Merge pull request #384 from lz4/dev

v1.8.0

10 files changed, 1517 insertions, 979 deletions

diff --git a/lib/Makefile b/lib/Makefile
index 2d9c8f3..9abb699 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -3,6 +3,8 @@
 # Copyright (C) Yann Collet 2011-2016
 # All rights reserved.
 #
+# This Makefile is validated for Linux, macOS, *BSD, Hurd, Solaris, MSYS2 targets
+#
 # BSD license
 # Redistribution and use in source and binary forms, with or without modification,
 # are permitted provided that the following conditions are met:
@@ -40,14 +42,14 @@ LIBVER_MINOR := $(shell echo $(LIBVER_MINOR_SCRIPT))
 LIBVER_PATCH := $(shell echo $(LIBVER_PATCH_SCRIPT))
 LIBVER  := $(shell echo $(LIBVER_SCRIPT))
 
-BUILD_STATIC:= yes
+BUILD_STATIC:=yes
 
 CPPFLAGS+= -DXXH_NAMESPACE=LZ4_
 CFLAGS  ?= -O3
-DEBUGFLAGS:=-g -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \
+DEBUGFLAGS:= -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \
            -Wswitch-enum -Wdeclaration-after-statement -Wstrict-prototypes -Wundef \
            -Wpointer-arith -Wstrict-aliasing=1
-CFLAGS  += $(MOREFLAGS)
+CFLAGS  += $(DEBUGFLAGS) $(MOREFLAGS)
 FLAGS    = $(CPPFLAGS) $(CFLAGS) $(LDFLAGS)
 
 
@@ -58,7 +60,7 @@ ifeq ($(shell uname), Darwin)
 	SHARED_EXT = dylib
 	SHARED_EXT_MAJOR = $(LIBVER_MAJOR).$(SHARED_EXT)
 	SHARED_EXT_VER = $(LIBVER).$(SHARED_EXT)
-	SONAME_FLAGS = -install_name $(PREFIX)/lib/liblz4.$(SHARED_EXT_MAJOR) -compatibility_version $(LIBVER_MAJOR) -current_version $(LIBVER)
+	SONAME_FLAGS = -install_name $(LIBDIR)/liblz4.$(SHARED_EXT_MAJOR) -compatibility_version $(LIBVER_MAJOR) -current_version $(LIBVER)
 else
 	SONAME_FLAGS = -Wl,-soname=liblz4.$(SHARED_EXT).$(LIBVER_MAJOR)
 	SHARED_EXT = so
@@ -68,12 +70,13 @@ endif
 
 LIBLZ4 = liblz4.$(SHARED_EXT_VER)
 
+.PHONY: default
 default: lib-release
 
-lib-release: liblz4.a liblz4
+lib-release: DEBUGFLAGS :=
+lib-release: lib
 
-lib: CFLAGS += $(DEBUGFLAGS)
-lib: lib-release
+lib: liblz4.a liblz4
 
 all: lib
 
@@ -81,7 +84,7 @@ all32: CFLAGS+=-m32
 all32: all
 
 liblz4.a: *.c
-ifeq ($(BUILD_STATIC),yes)
+ifeq ($(BUILD_STATIC),yes)  # can be disabled on command line
 	@echo compiling static library
 	@$(CC) $(CPPFLAGS) $(CFLAGS) -c $^
 	@$(AR) rcs $@ *.o
@@ -93,7 +96,7 @@ ifneq (,$(filter Windows%,$(OS)))
 	@$(CC) $(FLAGS) -DLZ4_DLL_EXPORT=1 -shared $^ -o dll\$@.dll
 	dlltool -D dll\liblz4.dll -d dll\liblz4.def -l dll\liblz4.lib
 else
-	@$(CC) $(FLAGS) -shared $^ -fPIC $(SONAME_FLAGS) -o $@
+	@$(CC) $(FLAGS) -shared $^ -fPIC -fvisibility=hidden $(SONAME_FLAGS) -o $@
 	@echo creating versioned links
 	@ln -sf $@ liblz4.$(SHARED_EXT_MAJOR)
 	@ln -sf $@ liblz4.$(SHARED_EXT)
@@ -112,16 +115,16 @@ clean:
 #-----------------------------------------------------------------------------
 ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU OpenBSD FreeBSD NetBSD DragonFly SunOS))
 
-ifneq (,$(filter $(shell uname),SunOS))
-INSTALL ?= ginstall
-else
-INSTALL ?= install
-endif
-
-PREFIX     ?= /usr/local
-DESTDIR    ?=
-LIBDIR     ?= $(PREFIX)/lib
-INCLUDEDIR ?= $(PREFIX)/include
+DESTDIR     ?=
+# directory variables : GNU convention prefers lowercase
+# support both lower and uppercase (BSD), use uppercase in script
+prefix      ?= /usr/local
+PREFIX      ?= $(prefix)
+exec_prefix ?= $(PREFIX)
+libdir      ?= $(exec_prefix)/lib
+LIBDIR      ?= $(libdir)
+includedir  ?= $(PREFIX)/include
+INCLUDEDIR  ?= $(includedir)
 
 ifneq (,$(filter $(shell uname),OpenBSD FreeBSD NetBSD DragonFly))
 PKGCONFIGDIR ?= $(PREFIX)/libdata/pkgconfig
@@ -129,8 +132,14 @@ else
 PKGCONFIGDIR ?= $(LIBDIR)/pkgconfig
 endif
 
-INSTALL_LIB  ?= $(INSTALL) -m 755
-INSTALL_DATA ?= $(INSTALL) -m 644
+ifneq (,$(filter $(shell uname),SunOS))
+INSTALL ?= ginstall
+else
+INSTALL ?= install
+endif
+
+INSTALL_PROGRAM ?= $(INSTALL)
+INSTALL_DATA    ?= $(INSTALL) -m 644
 
 liblz4.pc: liblz4.pc.in Makefile
 	@echo creating pkgconfig
@@ -141,20 +150,21 @@ liblz4.pc: liblz4.pc.in Makefile
           $< >$@
 
 install: lib liblz4.pc
-	@$(INSTALL) -d -m 755 $(DESTDIR)$(PKGCONFIGDIR)/ $(DESTDIR)$(INCLUDEDIR)/
+	@$(INSTALL) -d -m 755 $(DESTDIR)$(PKGCONFIGDIR)/ $(DESTDIR)$(INCLUDEDIR)/ $(DESTDIR)$(LIBDIR)/
 	@$(INSTALL_DATA) liblz4.pc $(DESTDIR)$(PKGCONFIGDIR)/
 	@echo Installing libraries
 ifeq ($(BUILD_STATIC),yes)
-	@$(INSTALL_LIB) liblz4.a $(DESTDIR)$(LIBDIR)/liblz4.a
+	@$(INSTALL_DATA) liblz4.a $(DESTDIR)$(LIBDIR)/liblz4.a
+	@$(INSTALL_DATA) lz4frame_static.h $(DESTDIR)$(INCLUDEDIR)/lz4frame_static.h
 endif
-	@$(INSTALL_LIB) liblz4.$(SHARED_EXT_VER) $(DESTDIR)$(LIBDIR)
+	@$(INSTALL_PROGRAM) liblz4.$(SHARED_EXT_VER) $(DESTDIR)$(LIBDIR)
 	@ln -sf liblz4.$(SHARED_EXT_VER) $(DESTDIR)$(LIBDIR)/liblz4.$(SHARED_EXT_MAJOR)
 	@ln -sf liblz4.$(SHARED_EXT_VER) $(DESTDIR)$(LIBDIR)/liblz4.$(SHARED_EXT)
-	@echo Installing includes
+	@echo Installing headers in $(INCLUDEDIR)
 	@$(INSTALL_DATA) lz4.h $(DESTDIR)$(INCLUDEDIR)/lz4.h
 	@$(INSTALL_DATA) lz4hc.h $(DESTDIR)$(INCLUDEDIR)/lz4hc.h
 	@$(INSTALL_DATA) lz4frame.h $(DESTDIR)$(INCLUDEDIR)/lz4frame.h
-	@echo lz4 static and shared libraries installed
+	@echo lz4 libraries installed
 
 uninstall:
 	@$(RM) $(DESTDIR)$(LIBDIR)/pkgconfig/liblz4.pc
diff --git a/lib/lz4.c b/lib/lz4.c
index 143c36e..41c0a28 100644
--- a/lib/lz4.c
+++ b/lib/lz4.c
@@ -1,6 +1,6 @@
 /*
    LZ4 - Fast LZ compression algorithm
-   Copyright (C) 2011-2016, Yann Collet.
+   Copyright (C) 2011-2017, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
@@ -37,12 +37,12 @@
 *  Tuning parameters
 **************************************/
 /*
- * HEAPMODE :
+ * LZ4_HEAPMODE :
  * Select how default compression functions will allocate memory for their hash table,
  * in memory stack (0:default, fastest), or in memory heap (1:requires malloc()).
  */
-#ifndef HEAPMODE
-#  define HEAPMODE 0
+#ifndef LZ4_HEAPMODE
+#  define LZ4_HEAPMODE 0
 #endif
 
 /*
@@ -63,16 +63,15 @@
  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method is portable but violate C standard.
- *            It can generate buggy code on targets which generate assembly depending on alignment.
+ *            It can generate buggy code on targets which assembly generation depends on alignment.
  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
  * See https://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
-#ifndef LZ4_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
+#ifndef LZ4_FORCE_MEMORY_ACCESS   /* can be defined externally */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define LZ4_FORCE_MEMORY_ACCESS 2
-#  elif defined(__INTEL_COMPILER) || \
-  (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
+#  elif defined(__INTEL_COMPILER) || defined(__GNUC__)
 #    define LZ4_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
@@ -97,20 +96,27 @@
 *  Compiler Options
 **************************************/
 #ifdef _MSC_VER    /* Visual Studio */
-#  define FORCE_INLINE static __forceinline
 #  include <intrin.h>
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4293)        /* disable: C4293: too large shift (32-bits) */
-#else
-#  if defined(__GNUC__) || defined(__clang__)
-#    define FORCE_INLINE static inline __attribute__((always_inline))
-#  elif defined(__cplusplus) || (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
-#    define FORCE_INLINE static inline
-#  else
-#    define FORCE_INLINE static
-#  endif
 #endif  /* _MSC_VER */
 
+#ifndef FORCE_INLINE
+#  ifdef _MSC_VER    /* Visual Studio */
+#    define FORCE_INLINE static __forceinline
+#  else
+#    if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
+#      ifdef __GNUC__
+#        define FORCE_INLINE static inline __attribute__((always_inline))
+#      else
+#        define FORCE_INLINE static inline
+#      endif
+#    else
+#      define FORCE_INLINE static
+#    endif /* __STDC_VERSION__ */
+#  endif  /* _MSC_VER */
+#endif /* FORCE_INLINE */
+
 #if (defined(__GNUC__) && (__GNUC__ >= 3)) || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) || defined(__clang__)
 #  define expect(expr,value)    (__builtin_expect ((expr),(value)) )
 #else
@@ -281,10 +287,22 @@ static const int LZ4_minLength = (MFLIMIT+1);
 
 
 /*-************************************
-*  Common Utils
+*  Error detection
 **************************************/
 #define LZ4_STATIC_ASSERT(c)    { enum { LZ4_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2)
+#  include <stdio.h>
+#  define DEBUGLOG(l, ...) {                          \
+                if (l<=LZ4_DEBUG) {                   \
+                    fprintf(stderr, __FILE__ ": ");   \
+                    fprintf(stderr, __VA_ARGS__);     \
+                    fprintf(stderr, " \n");           \
+            }   }
+#else
+#  define DEBUGLOG(l, ...)      {}    /* disabled */
+#endif
+
 
 /*-************************************
 *  Common functions
@@ -678,7 +696,7 @@ int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int
 
 int LZ4_compress_fast(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
 {
-#if (HEAPMODE)
+#if (LZ4_HEAPMODE)
     void* ctxPtr = ALLOCATOR(1, sizeof(LZ4_stream_t));   /* malloc-calloc always properly aligned */
 #else
     LZ4_stream_t ctx;
@@ -687,7 +705,7 @@ int LZ4_compress_fast(const char* source, char* dest, int inputSize, int maxOutp
 
     int const result = LZ4_compress_fast_extState(ctxPtr, source, dest, inputSize, maxOutputSize, acceleration);
 
-#if (HEAPMODE)
+#if (LZ4_HEAPMODE)
     FREEMEM(ctxPtr);
 #endif
     return result;
@@ -891,7 +909,7 @@ static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src,
 
 int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targetDstSize)
 {
-#if (HEAPMODE)
+#if (LZ4_HEAPMODE)
     LZ4_stream_t* ctx = (LZ4_stream_t*)ALLOCATOR(1, sizeof(LZ4_stream_t));   /* malloc-calloc always properly aligned */
 #else
     LZ4_stream_t ctxBody;
@@ -900,7 +918,7 @@ int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targe
 
     int result = LZ4_compress_destSize_extState(ctx, src, dst, srcSizePtr, targetDstSize);
 
-#if (HEAPMODE)
+#if (LZ4_HEAPMODE)
     FREEMEM(ctx);
 #endif
     return result;
@@ -927,6 +945,7 @@ void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
 
 int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
 {
+    if (!LZ4_stream) return 0;   /* support free on NULL */
     FREEMEM(LZ4_stream);
     return (0);
 }
@@ -1266,11 +1285,6 @@ int LZ4_decompress_fast(const char* source, char* dest, int originalSize)
 
 /*===== streaming decompression functions =====*/
 
-/*
- * If you prefer dynamic allocation methods,
- * LZ4_createStreamDecode()
- * provides a pointer (void*) towards an initialized LZ4_streamDecode_t structure.
- */
 LZ4_streamDecode_t* LZ4_createStreamDecode(void)
 {
     LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOCATOR(1, sizeof(LZ4_streamDecode_t));
@@ -1279,6 +1293,7 @@ LZ4_streamDecode_t* LZ4_createStreamDecode(void)
 
 int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream)
 {
+    if (!LZ4_stream) return 0;   /* support free on NULL */
     FREEMEM(LZ4_stream);
     return 0;
 }
diff --git a/lib/lz4.h b/lib/lz4.h
index 0aae19c..86ca0d5 100644
--- a/lib/lz4.h
+++ b/lib/lz4.h
@@ -1,7 +1,7 @@
 /*
  *  LZ4 - Fast LZ compression algorithm
  *  Header File
- *  Copyright (C) 2011-2016, Yann Collet.
+ *  Copyright (C) 2011-2017, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
@@ -32,13 +32,13 @@
     - LZ4 homepage : http://www.lz4.org
     - LZ4 source repository : https://github.com/lz4/lz4
 */
-#ifndef LZ4_H_2983827168210
-#define LZ4_H_2983827168210
-
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
+#ifndef LZ4_H_2983827168210
+#define LZ4_H_2983827168210
+
 /* --- Dependency --- */
 #include <stddef.h>   /* size_t */
 
@@ -72,20 +72,24 @@ extern "C" {
 /*
 *  LZ4_DLL_EXPORT :
 *  Enable exporting of functions when building a Windows DLL
+*  LZ4LIB_API :
+*  Control library symbols visibility.
 */
 #if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
 #  define LZ4LIB_API __declspec(dllexport)
 #elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1)
 #  define LZ4LIB_API __declspec(dllimport) /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
+#elif defined(__GNUC__) && (__GNUC__ >= 4)
+#  define LZ4LIB_API __attribute__ ((__visibility__ ("default")))
 #else
 #  define LZ4LIB_API
 #endif
 
 
-/*========== Version =========== */
+/*------   Version   ------*/
 #define LZ4_VERSION_MAJOR    1    /* for breaking interface changes  */
-#define LZ4_VERSION_MINOR    7    /* for new (non-breaking) interface capabilities */
-#define LZ4_VERSION_RELEASE  5    /* for tweaks, bug-fixes, or development */
+#define LZ4_VERSION_MINOR    8    /* for new (non-breaking) interface capabilities */
+#define LZ4_VERSION_RELEASE  0    /* for tweaks, bug-fixes, or development */
 
 #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
 
@@ -94,8 +98,8 @@ extern "C" {
 #define LZ4_EXPAND_AND_QUOTE(str) LZ4_QUOTE(str)
 #define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION)
 
-LZ4LIB_API int LZ4_versionNumber (void);
-LZ4LIB_API const char* LZ4_versionString (void);
+LZ4LIB_API int LZ4_versionNumber (void);  /**< library version number; to be used when checking dll version */
+LZ4LIB_API const char* LZ4_versionString (void);   /**< library version string; to be used when checking dll version */
 
 
 /*-************************************
@@ -108,8 +112,9 @@ LZ4LIB_API const char* LZ4_versionString (void);
  * Reduced memory usage can improve speed, due to cache effect
  * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
  */
-#define LZ4_MEMORY_USAGE 14
-
+#ifndef LZ4_MEMORY_USAGE
+# define LZ4_MEMORY_USAGE 14
+#endif
 
 /*-************************************
 *  Simple Functions
@@ -251,19 +256,19 @@ LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, in
 
 /*! LZ4_compress_fast_continue() :
  *  Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
- *  Important : Previous data blocks are assumed to still be present and unmodified !
+ *  Important : Previous data blocks are assumed to remain present and unmodified !
  *  'dst' buffer must be already allocated.
- *  If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
- *  If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function returns a zero.
+ *  If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
+ *  If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function @return==0.
+ *  After an error, the stream status is invalid, it can only be reset or freed.
  */
-LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration);
+LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
 
 /*! LZ4_saveDict() :
- *  If previously compressed data block is not guaranteed to remain available at its memory location,
+ *  If previously compressed data block is not guaranteed to remain available at its current memory location,
  *  save it into a safer place (char* safeBuffer).
- *  Note : you don't need to call LZ4_loadDict() afterwards,
- *         dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue().
- *  Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.
+ *  Note : it's not necessary to call LZ4_loadDict() after LZ4_saveDict(), dictionary is immediately usable.
+ *  @return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.
  */
 LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize);
 
@@ -274,7 +279,8 @@ LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dict
 ************************************************/
 typedef union LZ4_streamDecode_u LZ4_streamDecode_t;   /* incomplete type (defined later) */
 
-/* creation / destruction of streaming decompression tracking structure */
+/*! LZ4_createStreamDecode() and LZ4_freeStreamDecode() :
+ *  creation / destruction of streaming decompression tracking structure */
 LZ4LIB_API LZ4_streamDecode_t* LZ4_createStreamDecode(void);
 LZ4LIB_API int                 LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
 
@@ -285,22 +291,21 @@ LZ4LIB_API int                 LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_str
  */
 LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
 
-/*!
-LZ4_decompress_*_continue() :
-    These decoding functions allow decompression of multiple blocks in "streaming" mode.
-    Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB)
-    In the case of a ring buffers, decoding buffer must be either :
-    - Exactly same size as encoding buffer, with same update rule (block boundaries at same positions)
-      In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB).
-    - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
-      maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block.
-      In which case, encoding and decoding buffers do not need to be synchronized,
-      and encoding ring buffer can have any size, including small ones ( < 64 KB).
-    - _At least_ 64 KB + 8 bytes + maxBlockSize.
-      In which case, encoding and decoding buffers do not need to be synchronized,
-      and encoding ring buffer can have any size, including larger than decoding buffer.
-    Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
-    and indicate where it is saved using LZ4_setStreamDecode()
+/*! LZ4_decompress_*_continue() :
+ *  These decoding functions allow decompression of multiple blocks in "streaming" mode.
+ *  Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB)
+ *  In the case of a ring buffers, decoding buffer must be either :
+ *  - Exactly same size as encoding buffer, with same update rule (block boundaries at same positions)
+ *    In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB).
+ *  - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
+ *    maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block.
+ *    In which case, encoding and decoding buffers do not need to be synchronized,
+ *    and encoding ring buffer can have any size, including small ones ( < 64 KB).
+ *  - _At least_ 64 KB + 8 bytes + maxBlockSize.
+ *    In which case, encoding and decoding buffers do not need to be synchronized,
+ *    and encoding ring buffer can have any size, including larger than decoding buffer.
+ *  Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
+ *  and indicate where it is saved using LZ4_setStreamDecode()
 */
 LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize);
 LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);
@@ -374,7 +379,7 @@ typedef struct {
  * init this structure before first use.
  * note : only use in association with static linking !
  *        this definition is not API/ABI safe,
- *        and may change in a future version !
+ *        it may change in a future version !
  */
 #define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4)
 #define LZ4_STREAMSIZE     (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long))
@@ -400,11 +405,12 @@ union LZ4_streamDecode_u {
 } ;   /* previously typedef'd to LZ4_streamDecode_t */
 
 
-/*=************************************
+/*-************************************
 *  Obsolete Functions
 **************************************/
-/* Deprecation warnings */
-/* Should these warnings be a problem,
+
+/*! Deprecation warnings
+   Should deprecation warnings be a problem,
    it is generally possible to disable them,
    typically with -Wno-deprecated-declarations for gcc
    or _CRT_SECURE_NO_WARNINGS in Visual.
@@ -428,36 +434,30 @@ union LZ4_streamDecode_u {
 #endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */
 
 /* Obsolete compression functions */
-LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress               (const char* source, char* dest, int sourceSize);
-LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
-LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_withState               (void* state, const char* source, char* dest, int inputSize);
-LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
-LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_continue                (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
-LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_limitedOutput_continue  (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress               (const char* source, char* dest, int sourceSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_withState               (void* state, const char* source, char* dest, int inputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_continue                (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_limitedOutput_continue  (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
 
 /* Obsolete decompression functions */
-/* These function names are completely deprecated and must no longer be used.
-   They are only provided in lz4.c for compatibility with older programs.
-    - LZ4_uncompress is the same as LZ4_decompress_fast
-    - LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe
-   These function prototypes are now disabled; uncomment them only if you really need them.
-   It is highly recommended to stop using these prototypes and migrate to maintained ones */
-/* int LZ4_uncompress (const char* source, char* dest, int outputSize); */
-/* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_decompress_fast() instead") int LZ4_uncompress (const char* source, char* dest, int outputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_decompress_safe() instead") int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize);
 
 /* Obsolete streaming functions; use new streaming interface whenever possible */
-LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer);
-LZ4_DEPRECATED("use LZ4_createStream() instead") int   LZ4_sizeofStreamState(void);
-LZ4_DEPRECATED("use LZ4_resetStream() instead")  int   LZ4_resetStreamState(void* state, char* inputBuffer);
-LZ4_DEPRECATED("use LZ4_saveDict() instead")     char* LZ4_slideInputBuffer (void* state);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_createStream() instead") int   LZ4_sizeofStreamState(void);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_resetStream() instead")  int   LZ4_resetStreamState(void* state, char* inputBuffer);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_saveDict() instead")     char* LZ4_slideInputBuffer (void* state);
 
 /* Obsolete streaming decoding functions */
-LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
-LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
+
+#endif /* LZ4_H_2983827168210 */
 
 
 #if defined (__cplusplus)
 }
 #endif
-
-#endif /* LZ4_H_2983827168210 */
diff --git a/lib/lz4frame.c b/lib/lz4frame.c
index a0a625b..3408708 100644
--- a/lib/lz4frame.c
+++ b/lib/lz4frame.c
@@ -61,15 +61,16 @@ You can contact the author at :
 **************************************/
 #include "lz4frame_static.h"
 #include "lz4.h"
+#define LZ4_HC_STATIC_LINKING_ONLY
 #include "lz4hc.h"
 #define XXH_STATIC_LINKING_ONLY
 #include "xxhash.h"
 
 
 /*-************************************
-*  Common Utils
+*  Debug
 **************************************/
-#define LZ4_STATIC_ASSERT(c)    { enum { LZ4_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
+#define LZ4F_STATIC_ASSERT(c)    { enum { LZ4F_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
 /*-************************************
@@ -158,7 +159,7 @@ static void LZ4F_writeLE64 (void* dst, U64 value64)
 #define LZ4F_BLOCKSIZEID_DEFAULT LZ4F_max64KB
 
 static const size_t minFHSize = 7;
-static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX;   /* 15 */
+static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX;   /* 19 */
 static const size_t BHSize = 4;
 
 
@@ -170,6 +171,7 @@ typedef struct LZ4F_cctx_s
     LZ4F_preferences_t prefs;
     U32    version;
     U32    cStage;
+    const LZ4F_CDict* cdict;
     size_t maxBlockSize;
     size_t maxBufferSize;
     BYTE*  tmpBuff;
@@ -178,7 +180,7 @@ typedef struct LZ4F_cctx_s
     U64    totalInSize;
     XXH32_state_t xxh;
     void*  lz4CtxPtr;
-    U32    lz4CtxLevel;     /* 0: unallocated;  1: LZ4_stream_t;  3: LZ4_streamHC_t */
+    U32    lz4CtxLevel;   /* 0: unallocated;  1: LZ4_stream_t;  3: LZ4_streamHC_t */
 } LZ4F_cctx_t;
 
 
@@ -209,12 +211,15 @@ LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult)
 
 static LZ4F_errorCode_t err0r(LZ4F_errorCodes code)
 {
-    LZ4_STATIC_ASSERT(sizeof(ptrdiff_t) >= sizeof(size_t));    /* A compilation error here means sizeof(ptrdiff_t) is not large enough */
+    /* A compilation error here means sizeof(ptrdiff_t) is not large enough */
+    LZ4F_STATIC_ASSERT(sizeof(ptrdiff_t) >= sizeof(size_t));
     return (LZ4F_errorCode_t)-(ptrdiff_t)code;
 }
 
 unsigned LZ4F_getVersion(void) { return LZ4F_VERSION; }
 
+int LZ4F_compressionLevel_max(void) { return LZ4HC_CLEVEL_MAX; }
+
 
 /*-************************************
 *  Private functions
@@ -241,7 +246,8 @@ static BYTE LZ4F_headerChecksum (const void* header, size_t length)
 /*-************************************
 *  Simple-pass compression functions
 **************************************/
-static LZ4F_blockSizeID_t LZ4F_optimalBSID(const LZ4F_blockSizeID_t requestedBSID, const size_t srcSize)
+static LZ4F_blockSizeID_t LZ4F_optimalBSID(const LZ4F_blockSizeID_t requestedBSID,
+                                           const size_t srcSize)
 {
     LZ4F_blockSizeID_t proposedBSID = LZ4F_max64KB;
     size_t maxBlockSize = 64 KB;
@@ -254,21 +260,23 @@ static LZ4F_blockSizeID_t LZ4F_optimalBSID(const LZ4F_blockSizeID_t requestedBSI
     return requestedBSID;
 }
 
-/* LZ4F_compressBound() :
- * Provides dstCapacity given a srcSize to guarantee operation success in worst case situations.
- * prefsPtr is optional : you can provide NULL as argument, preferences will be set to cover worst case scenario.
- * Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers.
- * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
+/*! LZ4F_compressBound_internal() :
+ *  Provides dstCapacity given a srcSize to guarantee operation success in worst case situations.
+ *  prefsPtr is optional : if NULL is provided, preferences will be set to cover worst case scenario.
+ * @return is always the same for a srcSize and prefsPtr, so it can be relied upon to size reusable buffers.
+ *  When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
  */
-static size_t LZ4F_compressBound_internal(size_t srcSize, const LZ4F_preferences_t* preferencesPtr, size_t alreadyBuffered)
+static size_t LZ4F_compressBound_internal(size_t srcSize,
+                                    const LZ4F_preferences_t* preferencesPtr,
+                                          size_t alreadyBuffered)
 {
     LZ4F_preferences_t prefsNull;
     memset(&prefsNull, 0, sizeof(prefsNull));
     prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled;   /* worst case */
     {   const LZ4F_preferences_t* const prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr;
         U32 const flush = prefsPtr->autoFlush | (srcSize==0);
-        LZ4F_blockSizeID_t const bid = prefsPtr->frameInfo.blockSizeID;
-        size_t const blockSize = LZ4F_getBlockSize(bid);
+        LZ4F_blockSizeID_t const blockID = prefsPtr->frameInfo.blockSizeID;
+        size_t const blockSize = LZ4F_getBlockSize(blockID);
         size_t const maxBuffered = blockSize - 1;
         size_t const bufferedSize = MIN(alreadyBuffered, maxBuffered);
         size_t const maxSrcSize = srcSize + bufferedSize;
@@ -277,17 +285,19 @@ static size_t LZ4F_compressBound_internal(size_t srcSize, const LZ4F_preferences
         size_t const lastBlockSize = flush ? partialBlockSize : 0;
         unsigned const nbBlocks = nbFullBlocks + (lastBlockSize>0);
 
-        size_t const blockHeaderSize = 4;   /* default, without block CRC option (which cannot be generated with current API) */
+        size_t const blockHeaderSize = 4;
+        size_t const blockCRCSize = 4 * prefsPtr->frameInfo.blockChecksumFlag;
         size_t const frameEnd = 4 + (prefsPtr->frameInfo.contentChecksumFlag*4);
 
-        return (blockHeaderSize * nbBlocks) + (blockSize * nbFullBlocks) + lastBlockSize + frameEnd;;
+        return ((blockHeaderSize + blockCRCSize) * nbBlocks) +
+               (blockSize * nbFullBlocks) + lastBlockSize + frameEnd;
     }
 }
 
 size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
 {
     LZ4F_preferences_t prefs;
-    size_t const headerSize = maxFHSize;      /* max header size, including magic number and frame content size */
+    size_t const headerSize = maxFHSize;      /* max header size, including optional fields */
 
     if (preferencesPtr!=NULL) prefs = *preferencesPtr;
     else memset(&prefs, 0, sizeof(prefs));
@@ -297,16 +307,19 @@ size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* prefere
 }
 
 
-/*! LZ4F_compressFrame() :
-* Compress an entire srcBuffer into a valid LZ4 frame, as defined by specification v1.5.0, in a single step.
-* The most important rule is that dstBuffer MUST be large enough (dstMaxSize) to ensure compression completion even in worst case.
-* You can get the minimum value of dstMaxSize by using LZ4F_compressFrameBound()
-* If this condition is not respected, LZ4F_compressFrame() will fail (result is an errorCode)
-* The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will then be set to default.
-* The result of the function is the number of bytes written into dstBuffer.
-* The function outputs an error code if it fails (can be tested using LZ4F_isError())
-*/
-size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
+/*! LZ4F_compressFrame_usingCDict() :
+ *  Compress srcBuffer using a dictionary, in a single step.
+ *  cdict can be NULL, in which case, no dictionary is used.
+ *  dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
+ *  The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
+ *  however, it's the only way to provide a dictID, so it's not recommended.
+ * @return : number of bytes written into dstBuffer,
+ *           or an error code if it fails (can be tested using LZ4F_isError())
+ */
+size_t LZ4F_compressFrame_usingCDict(void* dstBuffer, size_t dstCapacity,
+                               const void* srcBuffer, size_t srcSize,
+                               const LZ4F_CDict* cdict,
+                               const LZ4F_preferences_t* preferencesPtr)
 {
     LZ4F_cctx_t cctxI;
     LZ4_stream_t lz4ctx;
@@ -316,11 +329,9 @@ size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity, const void* srcBu
     BYTE* dstPtr = dstStart;
     BYTE* const dstEnd = dstStart + dstCapacity;
 
-    memset(&cctxI, 0, sizeof(cctxI));   /* works because no allocation */
-    memset(&options, 0, sizeof(options));
-
+    memset(&cctxI, 0, sizeof(cctxI));
     cctxI.version = LZ4F_VERSION;
-    cctxI.maxBufferSize = 5 MB;   /* mess with real buffer size to prevent allocation; works because autoflush==1 & stableSrc==1 */
+    cctxI.maxBufferSize = 5 MB;   /* mess with real buffer size to prevent dynamic allocation; works only because autoflush==1 & stableSrc==1 */
 
     if (preferencesPtr!=NULL)
         prefs = *preferencesPtr;
@@ -329,22 +340,23 @@ size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity, const void* srcBu
     if (prefs.frameInfo.contentSize != 0)
         prefs.frameInfo.contentSize = (U64)srcSize;   /* auto-correct content size if selected (!=0) */
 
-    if (prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
-        cctxI.lz4CtxPtr = &lz4ctx;
-        cctxI.lz4CtxLevel = 1;
-    }
-
     prefs.frameInfo.blockSizeID = LZ4F_optimalBSID(prefs.frameInfo.blockSizeID, srcSize);
     prefs.autoFlush = 1;
     if (srcSize <= LZ4F_getBlockSize(prefs.frameInfo.blockSizeID))
-        prefs.frameInfo.blockMode = LZ4F_blockIndependent;   /* no need for linked blocks */
+        prefs.frameInfo.blockMode = LZ4F_blockIndependent;   /* only one block => no need for inter-block link */
 
+    if (prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
+        cctxI.lz4CtxPtr = &lz4ctx;
+        cctxI.lz4CtxLevel = 1;
+    }  /* fast compression context pre-created on stack */
+
+    memset(&options, 0, sizeof(options));
     options.stableSrc = 1;
 
-    if (dstCapacity < LZ4F_compressFrameBound(srcSize, &prefs))
+    if (dstCapacity < LZ4F_compressFrameBound(srcSize, &prefs))  /* condition to guarantee success */
         return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
 
-    { size_t const headerSize = LZ4F_compressBegin(&cctxI, dstBuffer, dstCapacity, &prefs);  /* write header */
+    { size_t const headerSize = LZ4F_compressBegin_usingCDict(&cctxI, dstBuffer, dstCapacity, cdict, &prefs);  /* write header */
       if (LZ4F_isError(headerSize)) return headerSize;
       dstPtr += headerSize;   /* header size */ }
 
@@ -356,24 +368,91 @@ size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity, const void* srcBu
       if (LZ4F_isError(tailSize)) return tailSize;
       dstPtr += tailSize; }
 
-    if (prefs.compressionLevel >= LZ4HC_CLEVEL_MIN)   /* no allocation done with lz4 fast */
+    if (prefs.compressionLevel >= LZ4HC_CLEVEL_MIN)  /* Ctx allocation only for lz4hc */
         FREEMEM(cctxI.lz4CtxPtr);
 
     return (dstPtr - dstStart);
 }
 
 
+/*! LZ4F_compressFrame() :
+ *  Compress an entire srcBuffer into a valid LZ4 frame, in a single step.
+ *  dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
+ *  The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default.
+ * @return : number of bytes written into dstBuffer.
+ *           or an error code if it fails (can be tested using LZ4F_isError())
+ */
+size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity,
+                    const void* srcBuffer, size_t srcSize,
+                    const LZ4F_preferences_t* preferencesPtr)
+{
+    return LZ4F_compressFrame_usingCDict(dstBuffer, dstCapacity,
+                                         srcBuffer, srcSize,
+                                         NULL, preferencesPtr);
+}
+
+
+/*-***************************************************
+*   Dictionary compression
+*****************************************************/
+
+struct LZ4F_CDict_s {
+    void* dictContent;
+    LZ4_stream_t* fastCtx;
+    LZ4_streamHC_t* HCCtx;
+}; /* typedef'd to LZ4F_CDict within lz4frame_static.h */
+
+/*! LZ4F_createCDict() :
+ *  When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
+ *  LZ4F_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
+ *  LZ4F_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
+ * `dictBuffer` can be released after LZ4F_CDict creation, since its content is copied within CDict
+ * @return : digested dictionary for compression, or NULL if failed */
+LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize)
+{
+    const char* dictStart = (const char*)dictBuffer;
+    LZ4F_CDict* cdict = (LZ4F_CDict*) malloc(sizeof(*cdict));
+    if (!cdict) return NULL;
+    if (dictSize > 64 KB) {
+        dictStart += dictSize - 64 KB;
+        dictSize = 64 KB;
+    }
+    cdict->dictContent = ALLOCATOR(dictSize);
+    cdict->fastCtx = LZ4_createStream();
+    cdict->HCCtx = LZ4_createStreamHC();
+    if (!cdict->dictContent || !cdict->fastCtx || !cdict->HCCtx) {
+        LZ4F_freeCDict(cdict);
+        return NULL;
+    }
+    memcpy(cdict->dictContent, dictStart, dictSize);
+    LZ4_resetStream(cdict->fastCtx);
+    LZ4_loadDict (cdict->fastCtx, (const char*)cdict->dictContent, (int)dictSize);
+    LZ4_resetStreamHC(cdict->HCCtx, LZ4HC_CLEVEL_DEFAULT);
+    LZ4_loadDictHC(cdict->HCCtx, (const char*)cdict->dictContent, (int)dictSize);
+    return cdict;
+}
+
+void LZ4F_freeCDict(LZ4F_CDict* cdict)
+{
+    if (cdict==NULL) return;  /* support free on NULL */
+    FREEMEM(cdict->dictContent);
+    LZ4_freeStream(cdict->fastCtx);
+    LZ4_freeStreamHC(cdict->HCCtx);
+    FREEMEM(cdict);
+}
+
+
 /*-*********************************
 *  Advanced compression functions
 ***********************************/
 
 /*! LZ4F_createCompressionContext() :
- * The first thing to do is to create a compressionContext object, which will be used in all compression operations.
- * This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure.
- * The version provided MUST be LZ4F_VERSION. It is intended to track potential version differences between different binaries.
- * The function will provide a pointer to an allocated LZ4F_compressionContext_t object.
- * If the result LZ4F_errorCode_t is not OK_NoError, there was an error during context creation.
- * Object can release its memory using LZ4F_freeCompressionContext();
+ *  The first thing to do is to create a compressionContext object, which will be used in all compression operations.
+ *  This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure.
+ *  The version provided MUST be LZ4F_VERSION. It is intended to track potential incompatible differences between different binaries.
+ *  The function will provide a pointer to an allocated LZ4F_compressionContext_t object.
+ *  If the result LZ4F_errorCode_t is not OK_NoError, there was an error during context creation.
+ *  Object can release its memory using LZ4F_freeCompressionContext();
  */
 LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_compressionContext_t* LZ4F_compressionContextPtr, unsigned version)
 {
@@ -381,7 +460,7 @@ LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_compressionContext_t* LZ4F_c
     if (cctxPtr==NULL) return err0r(LZ4F_ERROR_allocation_failed);
 
     cctxPtr->version = version;
-    cctxPtr->cStage = 0;   /* Next stage : write header */
+    cctxPtr->cStage = 0;   /* Next stage : init stream */
 
     *LZ4F_compressionContextPtr = (LZ4F_compressionContext_t)cctxPtr;
 
@@ -393,8 +472,8 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_compressionContext_t LZ4F_comp
 {
     LZ4F_cctx_t* const cctxPtr = (LZ4F_cctx_t*)LZ4F_compressionContext;
 
-    if (cctxPtr != NULL) {  /* null pointers can be safely provided to this function, like free() */
-       FREEMEM(cctxPtr->lz4CtxPtr);
+    if (cctxPtr != NULL) {  /* support free on NULL */
+       FREEMEM(cctxPtr->lz4CtxPtr);  /* works because LZ4_streamHC_t and LZ4_stream_t are simple POD types */
        FREEMEM(cctxPtr->tmpBuff);
        FREEMEM(LZ4F_compressionContext);
     }
@@ -403,27 +482,28 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_compressionContext_t LZ4F_comp
 }
 
 
-/*! LZ4F_compressBegin() :
- * will write the frame header into dstBuffer.
- * dstBuffer must be large enough to accommodate a header (dstCapacity). Maximum header size is LZ4F_HEADER_SIZE_MAX bytes.
+/*! LZ4F_compressBegin_usingCDict() :
+ *  init streaming compression and writes frame header into dstBuffer.
+ *  dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes.
  * @return : number of bytes written into dstBuffer for the header
  *           or an error code (can be tested using LZ4F_isError())
  */
-size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const LZ4F_preferences_t* preferencesPtr)
+size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
+                          void* dstBuffer, size_t dstCapacity,
+                          const LZ4F_CDict* cdict,
+                          const LZ4F_preferences_t* preferencesPtr)
 {
     LZ4F_preferences_t prefNull;
     BYTE* const dstStart = (BYTE*)dstBuffer;
     BYTE* dstPtr = dstStart;
     BYTE* headerStart;
-    size_t requiredBuffSize;
 
     if (dstCapacity < maxFHSize) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
-    if (cctxPtr->cStage != 0) return err0r(LZ4F_ERROR_GENERIC);
     memset(&prefNull, 0, sizeof(prefNull));
     if (preferencesPtr == NULL) preferencesPtr = &prefNull;
     cctxPtr->prefs = *preferencesPtr;
 
-    /* ctx Management */
+    /* Ctx Management */
     {   U32 const tableID = (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) ? 1 : 2;  /* 0:nothing ; 1:LZ4 table ; 2:HC tables */
         if (cctxPtr->lz4CtxLevel < tableID) {
             FREEMEM(cctxPtr->lz4CtxPtr);
@@ -431,31 +511,48 @@ size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacit
                 cctxPtr->lz4CtxPtr = (void*)LZ4_createStream();
             else
                 cctxPtr->lz4CtxPtr = (void*)LZ4_createStreamHC();
+            if (cctxPtr->lz4CtxPtr == NULL) return err0r(LZ4F_ERROR_allocation_failed);
             cctxPtr->lz4CtxLevel = tableID;
-        }
-    }
+    }   }
 
     /* Buffer Management */
-    if (cctxPtr->prefs.frameInfo.blockSizeID == 0) cctxPtr->prefs.frameInfo.blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT;
+    if (cctxPtr->prefs.frameInfo.blockSizeID == 0)
+        cctxPtr->prefs.frameInfo.blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT;
     cctxPtr->maxBlockSize = LZ4F_getBlockSize(cctxPtr->prefs.frameInfo.blockSizeID);
 
-    requiredBuffSize = cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) * 128 KB);
-    if (preferencesPtr->autoFlush)
-        requiredBuffSize = (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) * 64 KB;   /* just needs dict */
+    {   size_t const requiredBuffSize = preferencesPtr->autoFlush ?
+                (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) * 64 KB :  /* only needs windows size */
+                cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) * 128 KB);
 
-    if (cctxPtr->maxBufferSize < requiredBuffSize) {
-        cctxPtr->maxBufferSize = requiredBuffSize;
-        FREEMEM(cctxPtr->tmpBuff);
-        cctxPtr->tmpBuff = (BYTE*)ALLOCATOR(requiredBuffSize);
-        if (cctxPtr->tmpBuff == NULL) return err0r(LZ4F_ERROR_allocation_failed);
-    }
+        if (cctxPtr->maxBufferSize < requiredBuffSize) {
+            cctxPtr->maxBufferSize = 0;
+            FREEMEM(cctxPtr->tmpBuff);
+            cctxPtr->tmpBuff = (BYTE*)ALLOCATOR(requiredBuffSize);
+            if (cctxPtr->tmpBuff == NULL) return err0r(LZ4F_ERROR_allocation_failed);
+            cctxPtr->maxBufferSize = requiredBuffSize;
+    }   }
     cctxPtr->tmpIn = cctxPtr->tmpBuff;
     cctxPtr->tmpInSize = 0;
     XXH32_reset(&(cctxPtr->xxh), 0);
-    if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
-        LZ4_resetStream((LZ4_stream_t*)(cctxPtr->lz4CtxPtr));
-    else
-        LZ4_resetStreamHC((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), cctxPtr->prefs.compressionLevel);
+
+    /* context init */
+    cctxPtr->cdict = cdict;
+    if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) {
+        /* frame init only for blockLinked : blockIndependent will be init at each block */
+        if (cdict) {
+            if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
+                memcpy(cctxPtr->lz4CtxPtr, cdict->fastCtx, sizeof(*cdict->fastCtx));
+            } else {
+                memcpy(cctxPtr->lz4CtxPtr, cdict->HCCtx, sizeof(*cdict->HCCtx));
+                LZ4_setCompressionLevel((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
+            }
+        } else {
+            if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
+                LZ4_resetStream((LZ4_stream_t*)(cctxPtr->lz4CtxPtr));
+            else
+                LZ4_resetStreamHC((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), cctxPtr->prefs.compressionLevel);
+        }
+    }
 
     /* Magic Number */
     LZ4F_writeLE32(dstPtr, LZ4F_MAGICNUMBER);
@@ -464,9 +561,11 @@ size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacit
 
     /* FLG Byte */
     *dstPtr++ = (BYTE)(((1 & _2BITS) << 6)    /* Version('01') */
-        + ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5)    /* Block mode */
-        + ((cctxPtr->prefs.frameInfo.contentChecksumFlag & _1BIT ) << 2)   /* Frame checksum */
-        + ((cctxPtr->prefs.frameInfo.contentSize > 0) << 3));   /* Frame content size */
+        + ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5)
+        + ((cctxPtr->prefs.frameInfo.blockChecksumFlag & _1BIT ) << 4)
+        + ((cctxPtr->prefs.frameInfo.contentSize > 0) << 3)
+        + ((cctxPtr->prefs.frameInfo.contentChecksumFlag & _1BIT ) << 2)
+        +  (cctxPtr->prefs.frameInfo.dictID > 0) );
     /* BD Byte */
     *dstPtr++ = (BYTE)((cctxPtr->prefs.frameInfo.blockSizeID & _3BITS) << 4);
     /* Optional Frame content size field */
@@ -475,16 +574,36 @@ size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacit
         dstPtr += 8;
         cctxPtr->totalInSize = 0;
     }
-    /* CRC Byte */
+    /* Optional dictionary ID field */
+    if (cctxPtr->prefs.frameInfo.dictID) {
+        LZ4F_writeLE32(dstPtr, cctxPtr->prefs.frameInfo.dictID);
+        dstPtr += 4;
+    }
+    /* Header CRC Byte */
     *dstPtr = LZ4F_headerChecksum(headerStart, dstPtr - headerStart);
     dstPtr++;
 
     cctxPtr->cStage = 1;   /* header written, now request input data block */
-
     return (dstPtr - dstStart);
 }
 
 
+/*! LZ4F_compressBegin() :
+ *  init streaming compression and writes frame header into dstBuffer.
+ *  dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes.
+ *  preferencesPtr can be NULL, in which case default parameters are selected.
+ * @return : number of bytes written into dstBuffer for the header
+ *           or an error code (can be tested using LZ4F_isError())
+ */
+size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr,
+                          void* dstBuffer, size_t dstCapacity,
+                          const LZ4F_preferences_t* preferencesPtr)
+{
+    return LZ4F_compressBegin_usingCDict(cctxPtr, dstBuffer, dstCapacity,
+                                         NULL, preferencesPtr);
+}
+
+
 /* LZ4F_compressBound() :
  *      @ return size of Dst buffer given a srcSize to handle worst case situations.
  *      The LZ4F_frameInfo_t structure is optional : if NULL, preferences will be set to cover worst case situations.
@@ -496,49 +615,75 @@ size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesP
 }
 
 
-typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level);
+typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level, const LZ4F_CDict* cdict);
 
-static size_t LZ4F_compressBlock(void* dst, const void* src, size_t srcSize, compressFunc_t compress, void* lz4ctx, int level)
+
+/*! LZ4F_makeBlock():
+ *  compress a single block, add header and checksum
+ *  assumption : dst buffer capacity is >= srcSize */
+static size_t LZ4F_makeBlock(void* dst, const void* src, size_t srcSize,
+                             compressFunc_t compress, void* lz4ctx, int level,
+                             const LZ4F_CDict* cdict, LZ4F_blockChecksum_t crcFlag)
 {
-    /* compress a single block */
     BYTE* const cSizePtr = (BYTE*)dst;
-    U32 cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+4), (int)(srcSize), (int)(srcSize-1), level);
+    U32 cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+4),
+                                      (int)(srcSize), (int)(srcSize-1),
+                                      level, cdict);
     LZ4F_writeLE32(cSizePtr, cSize);
     if (cSize == 0) {  /* compression failed */
         cSize = (U32)srcSize;
         LZ4F_writeLE32(cSizePtr, cSize | LZ4F_BLOCKUNCOMPRESSED_FLAG);
         memcpy(cSizePtr+4, src, srcSize);
     }
-    return cSize + 4;
+    if (crcFlag) {
+        U32 const crc32 = XXH32(cSizePtr+4, cSize, 0);  /* checksum of compressed data */
+        LZ4F_writeLE32(cSizePtr+4+cSize, crc32);
+    }
+    return 4 + cSize + ((U32)crcFlag)*4;
 }
 
 
-static int LZ4F_localLZ4_compress_limitedOutput_withState(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level)
+static int LZ4F_compressBlock(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
 {
-    (void) level;
-    return LZ4_compress_fast_extState(ctx, src, dst, srcSize, dstCapacity, 1);
+    int const acceleration = (level < -1) ? -level : 1;
+    if (cdict) {
+        memcpy(ctx, cdict->fastCtx, sizeof(*cdict->fastCtx));
+        return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration);
+    }
+    return LZ4_compress_fast_extState(ctx, src, dst, srcSize, dstCapacity, acceleration);
+}
+
+static int LZ4F_compressBlock_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
+{
+    int const acceleration = (level < -1) ? -level : 1;
+    (void)cdict; /* init once at beginning of frame */
+    return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration);
 }
 
-static int LZ4F_localLZ4_compress_limitedOutput_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level)
+static int LZ4F_compressBlockHC(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
 {
-    (void) level;
-    return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, 1);
+    if (cdict) {
+        memcpy(ctx, cdict->HCCtx, sizeof(*cdict->HCCtx));
+        LZ4_setCompressionLevel((LZ4_streamHC_t*)ctx, level);
+        return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
+    }
+    return LZ4_compress_HC_extStateHC(ctx, src, dst, srcSize, dstCapacity, level);
 }
 
-static int LZ4F_localLZ4_compressHC_limitedOutput_continue(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level)
+static int LZ4F_compressBlockHC_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
 {
-    (void) level;
-    return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstSize);
+    (void)level; (void)cdict; /* init once at beginning of frame */
+    return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
 }
 
 static compressFunc_t LZ4F_selectCompression(LZ4F_blockMode_t blockMode, int level)
 {
     if (level < LZ4HC_CLEVEL_MIN) {
-        if (blockMode == LZ4F_blockIndependent) return LZ4F_localLZ4_compress_limitedOutput_withState;
-        return LZ4F_localLZ4_compress_limitedOutput_continue;
+        if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlock;
+        return LZ4F_compressBlock_continue;
     }
-    if (blockMode == LZ4F_blockIndependent) return LZ4_compress_HC_extStateHC;
-    return LZ4F_localLZ4_compressHC_limitedOutput_continue;
+    if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlockHC;
+    return LZ4F_compressBlockHC_continue;
 }
 
 static int LZ4F_localSaveDict(LZ4F_cctx_t* cctxPtr)
@@ -551,15 +696,16 @@ static int LZ4F_localSaveDict(LZ4F_cctx_t* cctxPtr)
 typedef enum { notDone, fromTmpBuffer, fromSrcBuffer } LZ4F_lastBlockStatus;
 
 /*! LZ4F_compressUpdate() :
-* LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
-* The most important rule is that dstBuffer MUST be large enough (dstCapacity) to ensure compression completion even in worst case.
-* If this condition is not respected, LZ4F_compress() will fail (result is an errorCode)
-* You can get the minimum value of dstCapacity by using LZ4F_compressBound()
-* The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
-* The result of the function is the number of bytes written into dstBuffer : it can be zero, meaning input data was just buffered.
-* The function outputs an error code if it fails (can be tested using LZ4F_isError())
-*/
-size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* compressOptionsPtr)
+ *  LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
+ *  dstBuffer MUST be >= LZ4F_compressBound(srcSize, preferencesPtr).
+ *  LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
+ * @return : the number of bytes written into dstBuffer. It can be zero, meaning input data was just buffered.
+ *           or an error code if it fails (which can be tested using LZ4F_isError())
+ */
+size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
+                           void* dstBuffer, size_t dstCapacity,
+                     const void* srcBuffer, size_t srcSize,
+                     const LZ4F_compressOptions_t* compressOptionsPtr)
 {
     LZ4F_compressOptions_t cOptionsNull;
     size_t const blockSize = cctxPtr->maxBlockSize;
@@ -591,7 +737,9 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapaci
             memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, sizeToCopy);
             srcPtr += sizeToCopy;
 
-            dstPtr += LZ4F_compressBlock(dstPtr, cctxPtr->tmpIn, blockSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
+            dstPtr += LZ4F_makeBlock(dstPtr, cctxPtr->tmpIn, blockSize,
+                                     compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
+                                     cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag);
 
             if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += blockSize;
             cctxPtr->tmpInSize = 0;
@@ -599,16 +747,20 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapaci
     }
 
     while ((size_t)(srcEnd - srcPtr) >= blockSize) {
-        /* compress full block */
+        /* compress full blocks */
         lastBlockCompressed = fromSrcBuffer;
-        dstPtr += LZ4F_compressBlock(dstPtr, srcPtr, blockSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
+        dstPtr += LZ4F_makeBlock(dstPtr, srcPtr, blockSize,
+                                 compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
+                                 cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag);
         srcPtr += blockSize;
     }
 
     if ((cctxPtr->prefs.autoFlush) && (srcPtr < srcEnd)) {
         /* compress remaining input < blockSize */
         lastBlockCompressed = fromSrcBuffer;
-        dstPtr += LZ4F_compressBlock(dstPtr, srcPtr, srcEnd - srcPtr, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
+        dstPtr += LZ4F_makeBlock(dstPtr, srcPtr, srcEnd - srcPtr,
+                                 compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
+                                 cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag);
         srcPtr  = srcEnd;
     }
 
@@ -617,7 +769,7 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapaci
         if (compressOptionsPtr->stableSrc) {
             cctxPtr->tmpIn = cctxPtr->tmpBuff;
         } else {
-            int realDictSize = LZ4F_localSaveDict(cctxPtr);
+            int const realDictSize = LZ4F_localSaveDict(cctxPtr);
             if (realDictSize==0) return err0r(LZ4F_ERROR_GENERIC);
             cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
         }
@@ -627,7 +779,7 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapaci
     if ((cctxPtr->tmpIn + blockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize)   /* necessarily LZ4F_blockLinked && lastBlockCompressed==fromTmpBuffer */
         && !(cctxPtr->prefs.autoFlush))
     {
-        int realDictSize = LZ4F_localSaveDict(cctxPtr);
+        int const realDictSize = LZ4F_localSaveDict(cctxPtr);
         cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
     }
 
@@ -648,13 +800,13 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapaci
 
 
 /*! LZ4F_flush() :
-* Should you need to create compressed data immediately, without waiting for a block to be filled,
-* you can call LZ4_flush(), which will immediately compress any remaining data stored within compressionContext.
-* The result of the function is the number of bytes written into dstBuffer
-* (it can be zero, this means there was no data left within compressionContext)
-* The function outputs an error code if it fails (can be tested using LZ4F_isError())
-* The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
-*/
+ *  Should you need to create compressed data immediately, without waiting for a block to be filled,
+ *  you can call LZ4_flush(), which will immediately compress any remaining data stored within compressionContext.
+ *  The result of the function is the number of bytes written into dstBuffer
+ *  (it can be zero, this means there was no data left within compressionContext)
+ *  The function outputs an error code if it fails (can be tested using LZ4F_isError())
+ *  The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
+ */
 size_t LZ4F_flush(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* compressOptionsPtr)
 {
     BYTE* const dstStart = (BYTE*)dstBuffer;
@@ -670,7 +822,9 @@ size_t LZ4F_flush(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const
     compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel);
 
     /* compress tmp buffer */
-    dstPtr += LZ4F_compressBlock(dstPtr, cctxPtr->tmpIn, cctxPtr->tmpInSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
+    dstPtr += LZ4F_makeBlock(dstPtr, cctxPtr->tmpIn, cctxPtr->tmpInSize,
+                             compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
+                             cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag);
     if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += cctxPtr->tmpInSize;
     cctxPtr->tmpInSize = 0;
 
@@ -685,14 +839,14 @@ size_t LZ4F_flush(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const
 
 
 /*! LZ4F_compressEnd() :
-* When you want to properly finish the compressed frame, just call LZ4F_compressEnd().
-* It will flush whatever data remained within compressionContext (like LZ4_flush())
-* but also properly finalize the frame, with an endMark and a checksum.
-* The result of the function is the number of bytes written into dstBuffer (necessarily >= 4 (endMark size))
-* The function outputs an error code if it fails (can be tested using LZ4F_isError())
-* The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
-* compressionContext can then be used again, starting with LZ4F_compressBegin(). The preferences will remain the same.
-*/
+ * When you want to properly finish the compressed frame, just call LZ4F_compressEnd().
+ * It will flush whatever data remained within compressionContext (like LZ4_flush())
+ * but also properly finalize the frame, with an endMark and a checksum.
+ * The result of the function is the number of bytes written into dstBuffer (necessarily >= 4 (endMark size))
+ * The function outputs an error code if it fails (can be tested using LZ4F_isError())
+ * The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
+ * compressionContext can then be used again, starting with LZ4F_compressBegin(). The preferences will remain the same.
+ */
 size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstMaxSize, const LZ4F_compressOptions_t* compressOptionsPtr)
 {
     BYTE* const dstStart = (BYTE*)dstBuffer;
@@ -727,10 +881,23 @@ size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstMaxSize,
 *   Frame Decompression
 *****************************************************/
 
+typedef enum {
+    dstage_getFrameHeader=0, dstage_storeFrameHeader,
+    dstage_init,
+    dstage_getBlockHeader, dstage_storeBlockHeader,
+    dstage_copyDirect, dstage_getBlockChecksum,
+    dstage_getCBlock, dstage_storeCBlock,
+    dstage_decodeCBlock, dstage_decodeCBlock_intoDst,
+    dstage_decodeCBlock_intoTmp, dstage_flushOut,
+    dstage_getSuffix, dstage_storeSuffix,
+    dstage_getSFrameSize, dstage_storeSFrameSize,
+    dstage_skipSkippable
+} dStage_t;
+
 struct LZ4F_dctx_s {
     LZ4F_frameInfo_t frameInfo;
     U32    version;
-    U32    dStage;
+    dStage_t dStage;
     U64    frameRemainingSize;
     size_t maxBlockSize;
     size_t maxBufferSize;
@@ -738,40 +905,41 @@ struct LZ4F_dctx_s {
     size_t tmpInSize;
     size_t tmpInTarget;
     BYTE*  tmpOutBuffer;
-    const BYTE*  dict;
+    const BYTE* dict;
     size_t dictSize;
     BYTE*  tmpOut;
     size_t tmpOutSize;
     size_t tmpOutStart;
     XXH32_state_t xxh;
-    BYTE   header[16];
+    XXH32_state_t blockChecksum;
+    BYTE   header[LZ4F_HEADER_SIZE_MAX];
 };  /* typedef'd to LZ4F_dctx in lz4frame.h */
 
 
 /*! LZ4F_createDecompressionContext() :
-*   Create a decompressionContext object, which will track all decompression operations.
-*   Provides a pointer to a fully allocated and initialized LZ4F_decompressionContext object.
-*   Object can later be released using LZ4F_freeDecompressionContext().
-*   @return : if != 0, there was an error during context creation.
-*/
+ *  Create a decompressionContext object, which will track all decompression operations.
+ *  Provides a pointer to a fully allocated and initialized LZ4F_decompressionContext object.
+ *  Object can later be released using LZ4F_freeDecompressionContext().
+ * @return : if != 0, there was an error during context creation.
+ */
 LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** LZ4F_decompressionContextPtr, unsigned versionNumber)
 {
-    LZ4F_dctx* const dctxPtr = (LZ4F_dctx*)ALLOCATOR(sizeof(LZ4F_dctx));
-    if (dctxPtr==NULL) return err0r(LZ4F_ERROR_GENERIC);
+    LZ4F_dctx* const dctx = (LZ4F_dctx*)ALLOCATOR(sizeof(LZ4F_dctx));
+    if (dctx==NULL) return err0r(LZ4F_ERROR_GENERIC);
 
-    dctxPtr->version = versionNumber;
-    *LZ4F_decompressionContextPtr = dctxPtr;
+    dctx->version = versionNumber;
+    *LZ4F_decompressionContextPtr = dctx;
     return LZ4F_OK_NoError;
 }
 
-LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* const dctxPtr)
+LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx)
 {
     LZ4F_errorCode_t result = LZ4F_OK_NoError;
-    if (dctxPtr != NULL) {   /* can accept NULL input, like free() */
-      result = (LZ4F_errorCode_t)dctxPtr->dStage;
-      FREEMEM(dctxPtr->tmpIn);
-      FREEMEM(dctxPtr->tmpOutBuffer);
-      FREEMEM(dctxPtr);
+    if (dctx != NULL) {   /* can accept NULL input, like free() */
+      result = (LZ4F_errorCode_t)dctx->dStage;
+      FREEMEM(dctx->tmpIn);
+      FREEMEM(dctx->tmpOutBuffer);
+      FREEMEM(dctx);
     }
     return result;
 }
@@ -779,22 +947,18 @@ LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* const dctxPtr)
 
 /*==---   Streaming Decompression operations   ---==*/
 
-typedef enum { dstage_getHeader=0, dstage_storeHeader,
-    dstage_getCBlockSize, dstage_storeCBlockSize,
-    dstage_copyDirect,
-    dstage_getCBlock, dstage_storeCBlock,
-    dstage_decodeCBlock, dstage_decodeCBlock_intoDst,
-    dstage_decodeCBlock_intoTmp, dstage_flushOut,
-    dstage_getSuffix, dstage_storeSuffix,
-    dstage_getSFrameSize, dstage_storeSFrameSize,
-    dstage_skipSkippable
-} dStage_t;
+void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx)
+{
+    dctx->dStage = dstage_getFrameHeader;
+    dctx->dict = NULL;
+    dctx->dictSize = 0;
+}
 
 
 /*! LZ4F_headerSize() :
-*   @return : size of frame header
-*             or an error code, which can be tested using LZ4F_isError()
-*/
+ *   @return : size of frame header
+ *             or an error code, which can be tested using LZ4F_isError()
+ */
 static size_t LZ4F_headerSize(const void* src, size_t srcSize)
 {
     /* minimal srcSize to determine header size */
@@ -804,244 +968,245 @@ static size_t LZ4F_headerSize(const void* src, size_t srcSize)
     if ((LZ4F_readLE32(src) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) return 8;
 
     /* control magic number */
-    if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER) return err0r(LZ4F_ERROR_frameType_unknown);
+    if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER)
+        return err0r(LZ4F_ERROR_frameType_unknown);
 
     /* Frame Header Size */
     {   BYTE const FLG = ((const BYTE*)src)[4];
         U32 const contentSizeFlag = (FLG>>3) & _1BIT;
-        return contentSizeFlag ? maxFHSize : minFHSize;
+        U32 const dictIDFlag = FLG & _1BIT;
+        return minFHSize + (contentSizeFlag*8) + (dictIDFlag*4);
     }
 }
 
 
 /*! LZ4F_decodeHeader() :
-   input   : `src` points at the **beginning of the frame**
-   output  : set internal values of dctx, such as
-             dctxPtr->frameInfo and dctxPtr->dStage.
-             Also allocates internal buffers.
-   @return : nb Bytes read from srcVoidPtr (necessarily <= srcSize)
-             or an error code (testable with LZ4F_isError())
-*/
-static size_t LZ4F_decodeHeader(LZ4F_dctx* dctxPtr, const void* src, size_t srcSize)
+ *  input   : `src` points at the **beginning of the frame**
+ *  output  : set internal values of dctx, such as
+ *            dctx->frameInfo and dctx->dStage.
+ *            Also allocates internal buffers.
+ *  @return : nb Bytes read from src (necessarily <= srcSize)
+ *            or an error code (testable with LZ4F_isError())
+ */
+static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize)
 {
-    BYTE FLG, BD;
-    unsigned version, blockMode, blockChecksumFlag, contentSizeFlag, contentChecksumFlag, blockSizeID;
+    unsigned blockMode, blockChecksumFlag, contentSizeFlag, contentChecksumFlag, dictIDFlag, blockSizeID;
     size_t frameHeaderSize;
     const BYTE* srcPtr = (const BYTE*)src;
 
     /* need to decode header to get frameInfo */
     if (srcSize < minFHSize) return err0r(LZ4F_ERROR_frameHeader_incomplete);   /* minimal frame header size */
-    memset(&(dctxPtr->frameInfo), 0, sizeof(dctxPtr->frameInfo));
+    memset(&(dctx->frameInfo), 0, sizeof(dctx->frameInfo));
 
     /* special case : skippable frames */
     if ((LZ4F_readLE32(srcPtr) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) {
-        dctxPtr->frameInfo.frameType = LZ4F_skippableFrame;
-        if (src == (void*)(dctxPtr->header)) {
-            dctxPtr->tmpInSize = srcSize;
-            dctxPtr->tmpInTarget = 8;
-            dctxPtr->dStage = dstage_storeSFrameSize;
+        dctx->frameInfo.frameType = LZ4F_skippableFrame;
+        if (src == (void*)(dctx->header)) {
+            dctx->tmpInSize = srcSize;
+            dctx->tmpInTarget = 8;
+            dctx->dStage = dstage_storeSFrameSize;
             return srcSize;
         } else {
-            dctxPtr->dStage = dstage_getSFrameSize;
+            dctx->dStage = dstage_getSFrameSize;
             return 4;
         }
     }
 
     /* control magic number */
-    if (LZ4F_readLE32(srcPtr) != LZ4F_MAGICNUMBER) return err0r(LZ4F_ERROR_frameType_unknown);
-    dctxPtr->frameInfo.frameType = LZ4F_frame;
+    if (LZ4F_readLE32(srcPtr) != LZ4F_MAGICNUMBER)
+        return err0r(LZ4F_ERROR_frameType_unknown);
+    dctx->frameInfo.frameType = LZ4F_frame;
 
     /* Flags */
-    FLG = srcPtr[4];
-    version = (FLG>>6) & _2BITS;
-    blockMode = (FLG>>5) & _1BIT;
-    blockChecksumFlag = (FLG>>4) & _1BIT;
-    contentSizeFlag = (FLG>>3) & _1BIT;
-    contentChecksumFlag = (FLG>>2) & _1BIT;
+    {   U32 const FLG = srcPtr[4];
+        U32 const version = (FLG>>6) & _2BITS;
+        blockChecksumFlag = (FLG>>4) & _1BIT;
+        blockMode = (FLG>>5) & _1BIT;
+        contentSizeFlag = (FLG>>3) & _1BIT;
+        contentChecksumFlag = (FLG>>2) & _1BIT;
+        dictIDFlag = FLG & _1BIT;
+        /* validate */
+        if (((FLG>>1)&_1BIT) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bit */
+        if (version != 1) return err0r(LZ4F_ERROR_headerVersion_wrong);        /* Version Number, only supported value */
+    }
 
     /* Frame Header Size */
-    frameHeaderSize = contentSizeFlag ? maxFHSize : minFHSize;
+    frameHeaderSize = minFHSize + (contentSizeFlag*8) + (dictIDFlag*4);
 
     if (srcSize < frameHeaderSize) {
         /* not enough input to fully decode frame header */
-        if (srcPtr != dctxPtr->header)
-            memcpy(dctxPtr->header, srcPtr, srcSize);
-        dctxPtr->tmpInSize = srcSize;
-        dctxPtr->tmpInTarget = frameHeaderSize;
-        dctxPtr->dStage = dstage_storeHeader;
+        if (srcPtr != dctx->header)
+            memcpy(dctx->header, srcPtr, srcSize);
+        dctx->tmpInSize = srcSize;
+        dctx->tmpInTarget = frameHeaderSize;
+        dctx->dStage = dstage_storeFrameHeader;
         return srcSize;
     }
 
-    BD = srcPtr[5];
-    blockSizeID = (BD>>4) & _3BITS;
-
-    /* validate */
-    if (version != 1) return err0r(LZ4F_ERROR_headerVersion_wrong);        /* Version Number, only supported value */
-    if (blockChecksumFlag != 0) return err0r(LZ4F_ERROR_blockChecksum_unsupported); /* Not supported for the time being */
-    if (((FLG>>0)&_2BITS) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bits */
-    if (((BD>>7)&_1BIT) != 0) return err0r(LZ4F_ERROR_reservedFlag_set);   /* Reserved bit */
-    if (blockSizeID < 4) return err0r(LZ4F_ERROR_maxBlockSize_invalid);    /* 4-7 only supported values for the time being */
-    if (((BD>>0)&_4BITS) != 0) return err0r(LZ4F_ERROR_reservedFlag_set);  /* Reserved bits */
+    {   U32 const BD = srcPtr[5];
+        blockSizeID = (BD>>4) & _3BITS;
+        /* validate */
+        if (((BD>>7)&_1BIT) != 0) return err0r(LZ4F_ERROR_reservedFlag_set);   /* Reserved bit */
+        if (blockSizeID < 4) return err0r(LZ4F_ERROR_maxBlockSize_invalid);    /* 4-7 only supported values for the time being */
+        if (((BD>>0)&_4BITS) != 0) return err0r(LZ4F_ERROR_reservedFlag_set);  /* Reserved bits */
+    }
 
     /* check header */
-    { BYTE const HC = LZ4F_headerChecksum(srcPtr+4, frameHeaderSize-5);
-      if (HC != srcPtr[frameHeaderSize-1]) return err0r(LZ4F_ERROR_headerChecksum_invalid); }
+    {   BYTE const HC = LZ4F_headerChecksum(srcPtr+4, frameHeaderSize-5);
+        if (HC != srcPtr[frameHeaderSize-1])
+            return err0r(LZ4F_ERROR_headerChecksum_invalid);
+    }
 
     /* save */
-    dctxPtr->frameInfo.blockMode = (LZ4F_blockMode_t)blockMode;
-    dctxPtr->frameInfo.contentChecksumFlag = (LZ4F_contentChecksum_t)contentChecksumFlag;
-    dctxPtr->frameInfo.blockSizeID = (LZ4F_blockSizeID_t)blockSizeID;
-    dctxPtr->maxBlockSize = LZ4F_getBlockSize(blockSizeID);
+    dctx->frameInfo.blockMode = (LZ4F_blockMode_t)blockMode;
+    dctx->frameInfo.blockChecksumFlag = (LZ4F_blockChecksum_t)blockChecksumFlag;
+    dctx->frameInfo.contentChecksumFlag = (LZ4F_contentChecksum_t)contentChecksumFlag;
+    dctx->frameInfo.blockSizeID = (LZ4F_blockSizeID_t)blockSizeID;
+    dctx->maxBlockSize = LZ4F_getBlockSize(blockSizeID);
     if (contentSizeFlag)
-        dctxPtr->frameRemainingSize = dctxPtr->frameInfo.contentSize = LZ4F_readLE64(srcPtr+6);
-
-    /* init */
-    if (contentChecksumFlag) XXH32_reset(&(dctxPtr->xxh), 0);
-
-    /* internal buffers allocation */
-    {   size_t const bufferNeeded = dctxPtr->maxBlockSize + ((dctxPtr->frameInfo.blockMode==LZ4F_blockLinked) * 128 KB);
-        if (bufferNeeded > dctxPtr->maxBufferSize) {   /* tmp buffers too small */
-            FREEMEM(dctxPtr->tmpIn);
-            dctxPtr->tmpIn = (BYTE*)ALLOCATOR(dctxPtr->maxBlockSize);
-            if (dctxPtr->tmpIn == NULL) return err0r(LZ4F_ERROR_allocation_failed);
-            FREEMEM(dctxPtr->tmpOutBuffer);
-            dctxPtr->maxBufferSize = 0;
-            dctxPtr->tmpOutBuffer= (BYTE*)ALLOCATOR(bufferNeeded);
-            if (dctxPtr->tmpOutBuffer== NULL) return err0r(LZ4F_ERROR_allocation_failed);
-            dctxPtr->maxBufferSize = bufferNeeded;
-    }   }
-    dctxPtr->tmpInSize = 0;
-    dctxPtr->tmpInTarget = 0;
-    dctxPtr->dict = dctxPtr->tmpOutBuffer;
-    dctxPtr->dictSize = 0;
-    dctxPtr->tmpOut = dctxPtr->tmpOutBuffer;
-    dctxPtr->tmpOutStart = 0;
-    dctxPtr->tmpOutSize = 0;
+        dctx->frameRemainingSize =
+            dctx->frameInfo.contentSize = LZ4F_readLE64(srcPtr+6);
+    if (dictIDFlag)
+        dctx->frameInfo.dictID = LZ4F_readLE32(srcPtr + frameHeaderSize - 5);
 
-    dctxPtr->dStage = dstage_getCBlockSize;
+    dctx->dStage = dstage_init;
 
     return frameHeaderSize;
 }
 
 
 /*! LZ4F_getFrameInfo() :
-*   Decodes frame header information, such as blockSize. Usage is optional.
-*   The objective is to extract header information before receiving decompressed data, typically for allocation purposes.
-*   LZ4F_getFrameInfo() can also be used *after* starting decompression, on a valid LZ4F_decompressionContext_t.
-*   The number of bytes consumed from srcBuffer will be provided within *srcSizePtr (necessarily <= original value).
-*   Decompression must resume from where it stopped (srcBuffer + *srcSizePtr)
-*   @return : hint of the better `srcSize` to use for next call to LZ4F_decompress,
-*             or an error code which can be tested using LZ4F_isError().
-*/
-LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctxPtr, LZ4F_frameInfo_t* frameInfoPtr,
+ *  This function extracts frame parameters (max blockSize, frame checksum, etc.).
+ *  Usage is optional. Objective is to provide relevant information for allocation purposes.
+ *  This function works in 2 situations :
+ *   - At the beginning of a new frame, in which case it will decode this information from `srcBuffer`, and start the decoding process.
+ *     Amount of input data provided must be large enough to successfully decode the frame header.
+ *     A header size is variable, but is guaranteed to be <= LZ4F_HEADER_SIZE_MAX bytes. It's possible to provide more input data than this minimum.
+ *   - After decoding has been started. In which case, no input is read, frame parameters are extracted from dctx.
+ *  The number of bytes consumed from srcBuffer will be updated within *srcSizePtr (necessarily <= original value).
+ *  Decompression must resume from (srcBuffer + *srcSizePtr).
+ * @return : an hint about how many srcSize bytes LZ4F_decompress() expects for next call,
+ *           or an error code which can be tested using LZ4F_isError()
+ *  note 1 : in case of error, dctx is not modified. Decoding operations can resume from where they stopped.
+ *  note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure.
+ */
+LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx, LZ4F_frameInfo_t* frameInfoPtr,
                                    const void* srcBuffer, size_t* srcSizePtr)
 {
-    if (dctxPtr->dStage > dstage_storeHeader) {  /* note : requires dstage_* header related to be at beginning of enum */
+    if (dctx->dStage > dstage_storeFrameHeader) {  /* assumption :  dstage_* header enum at beginning of range */
         /* frameInfo already decoded */
         size_t o=0, i=0;
         *srcSizePtr = 0;
-        *frameInfoPtr = dctxPtr->frameInfo;
-        return LZ4F_decompress(dctxPtr, NULL, &o, NULL, &i, NULL);  /* returns : recommended nb of bytes for LZ4F_decompress() */
+        *frameInfoPtr = dctx->frameInfo;
+        /* returns : recommended nb of bytes for LZ4F_decompress() */
+        return LZ4F_decompress(dctx, NULL, &o, NULL, &i, NULL);
     } else {
-        size_t nextSrcSize, o=0;
-        size_t const hSize = LZ4F_headerSize(srcBuffer, *srcSizePtr);
-        if (LZ4F_isError(hSize)) { *srcSizePtr=0; return hSize; }
-        if (*srcSizePtr < hSize) { *srcSizePtr=0; return err0r(LZ4F_ERROR_frameHeader_incomplete); }
-
-        *srcSizePtr = hSize;
-        nextSrcSize = LZ4F_decompress(dctxPtr, NULL, &o, srcBuffer, srcSizePtr, NULL);
-        if (dctxPtr->dStage <= dstage_storeHeader) return err0r(LZ4F_ERROR_frameHeader_incomplete); /* should not happen, already checked */
-        *frameInfoPtr = dctxPtr->frameInfo;
-        return nextSrcSize;
-    }
-}
-
+        if (dctx->dStage == dstage_storeFrameHeader) {
+            /* frame decoding already started, in the middle of header => automatic fail */
+            *srcSizePtr = 0;
+            return err0r(LZ4F_ERROR_frameDecoding_alreadyStarted);
+        } else {
+            size_t decodeResult;
+            size_t const hSize = LZ4F_headerSize(srcBuffer, *srcSizePtr);
+            if (LZ4F_isError(hSize)) { *srcSizePtr=0; return hSize; }
+            if (*srcSizePtr < hSize) {
+                *srcSizePtr=0;
+                return err0r(LZ4F_ERROR_frameHeader_incomplete);
+            }
 
-/* trivial redirector, for common prototype */
-static int LZ4F_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize)
-{
-    (void)dictStart; (void)dictSize;
-    return LZ4_decompress_safe (source, dest, compressedSize, maxDecompressedSize);
+            decodeResult = LZ4F_decodeHeader(dctx, srcBuffer, hSize);
+            if (LZ4F_isError(decodeResult)) {
+                *srcSizePtr = 0;
+            } else {
+                *srcSizePtr = decodeResult;
+                decodeResult = BHSize;   /* block header size */
+            }
+            *frameInfoPtr = dctx->frameInfo;
+            return decodeResult;
+    }   }
 }
 
 
-static void LZ4F_updateDict(LZ4F_dctx* dctxPtr, const BYTE* dstPtr, size_t dstSize, const BYTE* dstPtr0, unsigned withinTmp)
+/* LZ4F_updateDict() :
+ * only used for LZ4F_blockLinked mode */
+static void LZ4F_updateDict(LZ4F_dctx* dctx, const BYTE* dstPtr, size_t dstSize, const BYTE* dstPtr0, unsigned withinTmp)
 {
-    if (dctxPtr->dictSize==0)
-        dctxPtr->dict = (const BYTE*)dstPtr;   /* priority to dictionary continuity */
+    if (dctx->dictSize==0)
+        dctx->dict = (const BYTE*)dstPtr;   /* priority to dictionary continuity */
 
-    if (dctxPtr->dict + dctxPtr->dictSize == dstPtr) {  /* dictionary continuity */
-        dctxPtr->dictSize += dstSize;
+    if (dctx->dict + dctx->dictSize == dstPtr) {  /* dictionary continuity */
+        dctx->dictSize += dstSize;
         return;
     }
 
     if (dstPtr - dstPtr0 + dstSize >= 64 KB) {  /* dstBuffer large enough to become dictionary */
-        dctxPtr->dict = (const BYTE*)dstPtr0;
-        dctxPtr->dictSize = dstPtr - dstPtr0 + dstSize;
+        dctx->dict = (const BYTE*)dstPtr0;
+        dctx->dictSize = dstPtr - dstPtr0 + dstSize;
         return;
     }
 
-    if ((withinTmp) && (dctxPtr->dict == dctxPtr->tmpOutBuffer)) {
-        /* assumption : dctxPtr->dict + dctxPtr->dictSize == dctxPtr->tmpOut + dctxPtr->tmpOutStart */
-        dctxPtr->dictSize += dstSize;
+    if ((withinTmp) && (dctx->dict == dctx->tmpOutBuffer)) {
+        /* assumption : dctx->dict + dctx->dictSize == dctx->tmpOut + dctx->tmpOutStart */
+        dctx->dictSize += dstSize;
         return;
     }
 
     if (withinTmp) { /* copy relevant dict portion in front of tmpOut within tmpOutBuffer */
-        size_t const preserveSize = dctxPtr->tmpOut - dctxPtr->tmpOutBuffer;
-        size_t copySize = 64 KB - dctxPtr->tmpOutSize;
-        const BYTE* const oldDictEnd = dctxPtr->dict + dctxPtr->dictSize - dctxPtr->tmpOutStart;
-        if (dctxPtr->tmpOutSize > 64 KB) copySize = 0;
+        size_t const preserveSize = dctx->tmpOut - dctx->tmpOutBuffer;
+        size_t copySize = 64 KB - dctx->tmpOutSize;
+        const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart;
+        if (dctx->tmpOutSize > 64 KB) copySize = 0;
         if (copySize > preserveSize) copySize = preserveSize;
 
-        memcpy(dctxPtr->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
+        memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
 
-        dctxPtr->dict = dctxPtr->tmpOutBuffer;
-        dctxPtr->dictSize = preserveSize + dctxPtr->tmpOutStart + dstSize;
+        dctx->dict = dctx->tmpOutBuffer;
+        dctx->dictSize = preserveSize + dctx->tmpOutStart + dstSize;
         return;
     }
 
-    if (dctxPtr->dict == dctxPtr->tmpOutBuffer) {    /* copy dst into tmp to complete dict */
-        if (dctxPtr->dictSize + dstSize > dctxPtr->maxBufferSize) {  /* tmp buffer not large enough */
+    if (dctx->dict == dctx->tmpOutBuffer) {    /* copy dst into tmp to complete dict */
+        if (dctx->dictSize + dstSize > dctx->maxBufferSize) {  /* tmp buffer not large enough */
             size_t const preserveSize = 64 KB - dstSize;   /* note : dstSize < 64 KB */
-            memcpy(dctxPtr->tmpOutBuffer, dctxPtr->dict + dctxPtr->dictSize - preserveSize, preserveSize);
-            dctxPtr->dictSize = preserveSize;
+            memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize);
+            dctx->dictSize = preserveSize;
         }
-        memcpy(dctxPtr->tmpOutBuffer + dctxPtr->dictSize, dstPtr, dstSize);
-        dctxPtr->dictSize += dstSize;
+        memcpy(dctx->tmpOutBuffer + dctx->dictSize, dstPtr, dstSize);
+        dctx->dictSize += dstSize;
         return;
     }
 
     /* join dict & dest into tmp */
     {   size_t preserveSize = 64 KB - dstSize;   /* note : dstSize < 64 KB */
-        if (preserveSize > dctxPtr->dictSize) preserveSize = dctxPtr->dictSize;
-        memcpy(dctxPtr->tmpOutBuffer, dctxPtr->dict + dctxPtr->dictSize - preserveSize, preserveSize);
-        memcpy(dctxPtr->tmpOutBuffer + preserveSize, dstPtr, dstSize);
-        dctxPtr->dict = dctxPtr->tmpOutBuffer;
-        dctxPtr->dictSize = preserveSize + dstSize;
+        if (preserveSize > dctx->dictSize) preserveSize = dctx->dictSize;
+        memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize);
+        memcpy(dctx->tmpOutBuffer + preserveSize, dstPtr, dstSize);
+        dctx->dict = dctx->tmpOutBuffer;
+        dctx->dictSize = preserveSize + dstSize;
     }
 }
 
 
 
 /*! LZ4F_decompress() :
-* Call this function repetitively to regenerate data compressed within srcBuffer.
-* The function will attempt to decode up to *srcSizePtr bytes from srcBuffer, into dstBuffer of capacity *dstSizePtr.
-*
-* The number of bytes regenerated into dstBuffer will be provided within *dstSizePtr (necessarily <= original value).
-*
-* The number of bytes effectively read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value).
-* If the number of bytes read is < number of bytes provided, then the decompression operation is not complete.
-* Remaining data will have to be presented again in a subsequent invocation.
-*
-* The function result is an hint of the better srcSize to use for next call to LZ4F_decompress.
-* Basically, it's the size of the current (or remaining) compressed block + header of next block.
-* Respecting the hint provides some boost to performance, since it allows less buffer shuffling.
-* Note that this is just a hint, it's always possible to any srcSize value.
-* When a frame is fully decoded, @return will be 0.
-* If decompression failed, @return is an error code which can be tested using LZ4F_isError().
-*/
-size_t LZ4F_decompress(LZ4F_dctx* dctxPtr,
+ *  Call this function repetitively to regenerate compressed data in srcBuffer.
+ *  The function will attempt to decode up to *srcSizePtr bytes from srcBuffer
+ *  into dstBuffer of capacity *dstSizePtr.
+ *
+ *  The number of bytes regenerated into dstBuffer will be provided within *dstSizePtr (necessarily <= original value).
+ *
+ *  The number of bytes effectively read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value).
+ *  If number of bytes read is < number of bytes provided, then decompression operation is not complete.
+ *  Remaining data will have to be presented again in a subsequent invocation.
+ *
+ *  The function result is an hint of the better srcSize to use for next call to LZ4F_decompress.
+ *  Schematically, it's the size of the current (or remaining) compressed block + header of next block.
+ *  Respecting the hint provides a small boost to performance, since it allows less buffer shuffling.
+ *  Note that this is just a hint, and it's always possible to any srcSize value.
+ *  When a frame is fully decoded, @return will be 0.
+ *  If decompression failed, @return is an error code which can be tested using LZ4F_isError().
+ */
+size_t LZ4F_decompress(LZ4F_dctx* dctx,
                        void* dstBuffer, size_t* dstSizePtr,
                        const void* srcBuffer, size_t* srcSizePtr,
                        const LZ4F_decompressOptions_t* decompressOptionsPtr)
@@ -1063,219 +1228,288 @@ size_t LZ4F_decompress(LZ4F_dctx* dctxPtr,
     *srcSizePtr = 0;
     *dstSizePtr = 0;
 
-    /* programmed as a state machine */
+    /* behaves as a state machine */
 
     while (doAnotherStage) {
 
-        switch(dctxPtr->dStage)
+        switch(dctx->dStage)
         {
 
-        case dstage_getHeader:
+        case dstage_getFrameHeader:
             if ((size_t)(srcEnd-srcPtr) >= maxFHSize) {  /* enough to decode - shortcut */
-                LZ4F_errorCode_t const hSize = LZ4F_decodeHeader(dctxPtr, srcPtr, srcEnd-srcPtr);
+                size_t const hSize = LZ4F_decodeHeader(dctx, srcPtr, srcEnd-srcPtr);  /* will update dStage appropriately */
                 if (LZ4F_isError(hSize)) return hSize;
                 srcPtr += hSize;
                 break;
             }
-            dctxPtr->tmpInSize = 0;
-            dctxPtr->tmpInTarget = minFHSize;   /* minimum to attempt decode */
-            dctxPtr->dStage = dstage_storeHeader;
-            /* pass-through */
-
-        case dstage_storeHeader:
-            {   size_t sizeToCopy = dctxPtr->tmpInTarget - dctxPtr->tmpInSize;
-                if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy =  srcEnd - srcPtr;
-                memcpy(dctxPtr->header + dctxPtr->tmpInSize, srcPtr, sizeToCopy);
-                dctxPtr->tmpInSize += sizeToCopy;
+            dctx->tmpInSize = 0;
+            if (srcEnd-srcPtr == 0) return minFHSize;   /* 0-size input */
+            dctx->tmpInTarget = minFHSize;   /* minimum to attempt decode */
+            dctx->dStage = dstage_storeFrameHeader;
+            /* fall-through */
+
+        case dstage_storeFrameHeader:
+            {   size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize, (size_t)(srcEnd - srcPtr));
+                memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
+                dctx->tmpInSize += sizeToCopy;
                 srcPtr += sizeToCopy;
-                if (dctxPtr->tmpInSize < dctxPtr->tmpInTarget) {
-                    nextSrcSizeHint = (dctxPtr->tmpInTarget - dctxPtr->tmpInSize) + BHSize;   /* rest of header + nextBlockHeader */
+                if (dctx->tmpInSize < dctx->tmpInTarget) {
+                    nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + BHSize;   /* rest of header + nextBlockHeader */
                     doAnotherStage = 0;   /* not enough src data, ask for some more */
                     break;
                 }
-                {   LZ4F_errorCode_t const hSize = LZ4F_decodeHeader(dctxPtr, dctxPtr->header, dctxPtr->tmpInTarget);
+                {   size_t const hSize = LZ4F_decodeHeader(dctx, dctx->header, dctx->tmpInTarget);  /* will update dStage appropriately */
                     if (LZ4F_isError(hSize)) return hSize;
                 }
                 break;
             }
 
-        case dstage_getCBlockSize:
+        case dstage_init:
+            if (dctx->frameInfo.contentChecksumFlag) XXH32_reset(&(dctx->xxh), 0);
+            /* internal buffers allocation */
+            {   size_t const bufferNeeded = dctx->maxBlockSize + ((dctx->frameInfo.blockMode==LZ4F_blockLinked) * 128 KB) + 4 /* block checksum */;
+                if (bufferNeeded > dctx->maxBufferSize) {   /* tmp buffers too small */
+                    dctx->maxBufferSize = 0;   /* ensure allocation will be re-attempted on next entry*/
+                    FREEMEM(dctx->tmpIn);
+                    dctx->tmpIn = (BYTE*)ALLOCATOR(dctx->maxBlockSize);
+                    if (dctx->tmpIn == NULL) return err0r(LZ4F_ERROR_allocation_failed);
+                    FREEMEM(dctx->tmpOutBuffer);
+                    dctx->tmpOutBuffer= (BYTE*)ALLOCATOR(bufferNeeded);
+                    if (dctx->tmpOutBuffer== NULL) return err0r(LZ4F_ERROR_allocation_failed);
+                    dctx->maxBufferSize = bufferNeeded;
+            }   }
+            dctx->tmpInSize = 0;
+            dctx->tmpInTarget = 0;
+            dctx->tmpOut = dctx->tmpOutBuffer;
+            dctx->tmpOutStart = 0;
+            dctx->tmpOutSize = 0;
+
+            dctx->dStage = dstage_getBlockHeader;
+            /* fall-through */
+
+        case dstage_getBlockHeader:
             if ((size_t)(srcEnd - srcPtr) >= BHSize) {
                 selectedIn = srcPtr;
                 srcPtr += BHSize;
             } else {
                 /* not enough input to read cBlockSize field */
-                dctxPtr->tmpInSize = 0;
-                dctxPtr->dStage = dstage_storeCBlockSize;
+                dctx->tmpInSize = 0;
+                dctx->dStage = dstage_storeBlockHeader;
             }
 
-            if (dctxPtr->dStage == dstage_storeCBlockSize)   /* can be skipped */
-        case dstage_storeCBlockSize:
-            {   size_t sizeToCopy = BHSize - dctxPtr->tmpInSize;
+            if (dctx->dStage == dstage_storeBlockHeader)   /* can be skipped */
+        case dstage_storeBlockHeader:
+            {   size_t sizeToCopy = BHSize - dctx->tmpInSize;
                 if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr;
-                memcpy(dctxPtr->tmpIn + dctxPtr->tmpInSize, srcPtr, sizeToCopy);
+                memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
                 srcPtr += sizeToCopy;
-                dctxPtr->tmpInSize += sizeToCopy;
-                if (dctxPtr->tmpInSize < BHSize) {   /* not enough input to get full cBlockSize; wait for more */
-                    nextSrcSizeHint = BHSize - dctxPtr->tmpInSize;
+                dctx->tmpInSize += sizeToCopy;
+                if (dctx->tmpInSize < BHSize) {   /* not enough input for cBlockSize */
+                    nextSrcSizeHint = BHSize - dctx->tmpInSize;
                     doAnotherStage  = 0;
                     break;
                 }
-                selectedIn = dctxPtr->tmpIn;
+                selectedIn = dctx->tmpIn;
             }
 
-        /* case dstage_decodeCBlockSize: */   /* no more direct access, to prevent scan-build warning */
+        /* decode block header */
             {   size_t const nextCBlockSize = LZ4F_readLE32(selectedIn) & 0x7FFFFFFFU;
-                if (nextCBlockSize==0) {  /* frameEnd signal, no more CBlock */
-                    dctxPtr->dStage = dstage_getSuffix;
+                size_t const crcSize = dctx->frameInfo.blockChecksumFlag * 4;
+                if (nextCBlockSize==0) {  /* frameEnd signal, no more block */
+                    dctx->dStage = dstage_getSuffix;
                     break;
                 }
-                if (nextCBlockSize > dctxPtr->maxBlockSize) return err0r(LZ4F_ERROR_GENERIC);   /* invalid cBlockSize */
-                dctxPtr->tmpInTarget = nextCBlockSize;
+                if (nextCBlockSize > dctx->maxBlockSize)
+                    return err0r(LZ4F_ERROR_maxBlockSize_invalid);
                 if (LZ4F_readLE32(selectedIn) & LZ4F_BLOCKUNCOMPRESSED_FLAG) {
-                    dctxPtr->dStage = dstage_copyDirect;
+                    /* next block is uncompressed */
+                    dctx->tmpInTarget = nextCBlockSize;
+                    if (dctx->frameInfo.blockChecksumFlag) {
+                        XXH32_reset(&dctx->blockChecksum, 0);
+                    }
+                    dctx->dStage = dstage_copyDirect;
                     break;
                 }
-                dctxPtr->dStage = dstage_getCBlock;
+                /* next block is a compressed block */
+                dctx->tmpInTarget = nextCBlockSize + crcSize;
+                dctx->dStage = dstage_getCBlock;
                 if (dstPtr==dstEnd) {
-                    nextSrcSizeHint = nextCBlockSize + BHSize;
+                    nextSrcSizeHint = nextCBlockSize + crcSize + BHSize;
                     doAnotherStage = 0;
                 }
                 break;
             }
 
         case dstage_copyDirect:   /* uncompressed block */
-            {   size_t sizeToCopy = dctxPtr->tmpInTarget;
-                if ((size_t)(srcEnd-srcPtr) < sizeToCopy) sizeToCopy = srcEnd - srcPtr;  /* not enough input to read full block */
-                if ((size_t)(dstEnd-dstPtr) < sizeToCopy) sizeToCopy = dstEnd - dstPtr;
+            {   size_t const minBuffSize = MIN((size_t)(srcEnd-srcPtr), (size_t)(dstEnd-dstPtr));
+                size_t const sizeToCopy = MIN(dctx->tmpInTarget, minBuffSize);
                 memcpy(dstPtr, srcPtr, sizeToCopy);
-                if (dctxPtr->frameInfo.contentChecksumFlag) XXH32_update(&(dctxPtr->xxh), srcPtr, sizeToCopy);
-                if (dctxPtr->frameInfo.contentSize) dctxPtr->frameRemainingSize -= sizeToCopy;
+                if (dctx->frameInfo.blockChecksumFlag) {
+                    XXH32_update(&dctx->blockChecksum, srcPtr, sizeToCopy);
+                }
+                if (dctx->frameInfo.contentChecksumFlag)
+                    XXH32_update(&dctx->xxh, srcPtr, sizeToCopy);
+                if (dctx->frameInfo.contentSize)
+                    dctx->frameRemainingSize -= sizeToCopy;
 
-                /* dictionary management */
-                if (dctxPtr->frameInfo.blockMode==LZ4F_blockLinked)
-                    LZ4F_updateDict(dctxPtr, dstPtr, sizeToCopy, dstStart, 0);
+                /* history management (linked blocks only)*/
+                if (dctx->frameInfo.blockMode == LZ4F_blockLinked)
+                    LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 0);
 
                 srcPtr += sizeToCopy;
                 dstPtr += sizeToCopy;
-                if (sizeToCopy == dctxPtr->tmpInTarget) {  /* all copied */
-                    dctxPtr->dStage = dstage_getCBlockSize;
+                if (sizeToCopy == dctx->tmpInTarget) {   /* all done */
+                    if (dctx->frameInfo.blockChecksumFlag) {
+                        dctx->tmpInSize = 0;
+                        dctx->dStage = dstage_getBlockChecksum;
+                    } else
+                        dctx->dStage = dstage_getBlockHeader;  /* new block */
                     break;
                 }
-                dctxPtr->tmpInTarget -= sizeToCopy;   /* still need to copy more */
-                nextSrcSizeHint = dctxPtr->tmpInTarget + BHSize;
+                dctx->tmpInTarget -= sizeToCopy;  /* need to copy more */
+                nextSrcSizeHint = dctx->tmpInTarget +
+                                + dctx->frameInfo.contentChecksumFlag * 4  /* block checksum */
+                                + BHSize /* next header size */;
                 doAnotherStage = 0;
                 break;
             }
 
+        /* check block checksum for recently transferred uncompressed block */
+        case dstage_getBlockChecksum:
+            {   const void* crcSrc;
+                if ((srcEnd-srcPtr >= 4) && (dctx->tmpInSize==0)) {
+                    crcSrc = srcPtr;
+                    srcPtr += 4;
+                } else {
+                    size_t const stillToCopy = 4 - dctx->tmpInSize;
+                    size_t const sizeToCopy = MIN(stillToCopy, (size_t)(srcEnd-srcPtr));
+                    memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
+                    dctx->tmpInSize += sizeToCopy;
+                    srcPtr += sizeToCopy;
+                    if (dctx->tmpInSize < 4) {  /* all input consumed */
+                        doAnotherStage = 0;
+                        break;
+                    }
+                    crcSrc = dctx->header;
+                }
+                {   U32 const readCRC = LZ4F_readLE32(crcSrc);
+                    U32 const calcCRC = XXH32_digest(&dctx->blockChecksum);
+                    if (readCRC != calcCRC)
+                        return err0r(LZ4F_ERROR_blockChecksum_invalid);
+                }
+            }
+            dctx->dStage = dstage_getBlockHeader;  /* new block */
+            break;
+
         case dstage_getCBlock:   /* entry from dstage_decodeCBlockSize */
-            if ((size_t)(srcEnd-srcPtr) < dctxPtr->tmpInTarget) {
-                dctxPtr->tmpInSize = 0;
-                dctxPtr->dStage = dstage_storeCBlock;
+            if ((size_t)(srcEnd-srcPtr) < dctx->tmpInTarget) {
+                dctx->tmpInSize = 0;
+                dctx->dStage = dstage_storeCBlock;
                 break;
             }
+            /* input large enough to read full block directly */
             selectedIn = srcPtr;
-            srcPtr += dctxPtr->tmpInTarget;
-            dctxPtr->dStage = dstage_decodeCBlock;
+            srcPtr += dctx->tmpInTarget;
+            dctx->dStage = dstage_decodeCBlock;
             break;
 
         case dstage_storeCBlock:
-            {   size_t sizeToCopy = dctxPtr->tmpInTarget - dctxPtr->tmpInSize;
-                if (sizeToCopy > (size_t)(srcEnd-srcPtr)) sizeToCopy = srcEnd-srcPtr;
-                memcpy(dctxPtr->tmpIn + dctxPtr->tmpInSize, srcPtr, sizeToCopy);
-                dctxPtr->tmpInSize += sizeToCopy;
+            {   size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize, (size_t)(srcEnd-srcPtr));
+                memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
+                dctx->tmpInSize += sizeToCopy;
                 srcPtr += sizeToCopy;
-                if (dctxPtr->tmpInSize < dctxPtr->tmpInTarget) { /* need more input */
-                    nextSrcSizeHint = (dctxPtr->tmpInTarget - dctxPtr->tmpInSize) + BHSize;
+                if (dctx->tmpInSize < dctx->tmpInTarget) { /* need more input */
+                    nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + BHSize;
                     doAnotherStage=0;
                     break;
                 }
-                selectedIn = dctxPtr->tmpIn;
-                dctxPtr->dStage = dstage_decodeCBlock;
-                /* pass-through */
+                selectedIn = dctx->tmpIn;
+                dctx->dStage = dstage_decodeCBlock;
             }
+            /* fall-through */
 
+        /* At this stage, input is large enough to decode a block */
         case dstage_decodeCBlock:
-            if ((size_t)(dstEnd-dstPtr) < dctxPtr->maxBlockSize)   /* not enough place into dst : decode into tmpOut */
-                dctxPtr->dStage = dstage_decodeCBlock_intoTmp;
+            if (dctx->frameInfo.blockChecksumFlag) {
+                dctx->tmpInTarget -= 4;
+                {   U32 const readBlockCrc = LZ4F_readLE32(selectedIn + dctx->tmpInTarget);
+                    U32 const calcBlockCrc = XXH32(selectedIn, dctx->tmpInTarget, 0);
+                    if (readBlockCrc != calcBlockCrc)
+                        return err0r(LZ4F_ERROR_blockChecksum_invalid);
+            }   }
+            if ((size_t)(dstEnd-dstPtr) < dctx->maxBlockSize)   /* not enough place into dst : decode into tmpOut */
+                dctx->dStage = dstage_decodeCBlock_intoTmp;
             else
-                dctxPtr->dStage = dstage_decodeCBlock_intoDst;
+                dctx->dStage = dstage_decodeCBlock_intoDst;
             break;
 
         case dstage_decodeCBlock_intoDst:
-            {   int (*decoder)(const char*, char*, int, int, const char*, int);
-                int decodedSize;
-
-                if (dctxPtr->frameInfo.blockMode == LZ4F_blockLinked)
-                    decoder = LZ4_decompress_safe_usingDict;
-                else
-                    decoder = LZ4F_decompress_safe;
-
-                decodedSize = decoder((const char*)selectedIn, (char*)dstPtr, (int)dctxPtr->tmpInTarget, (int)dctxPtr->maxBlockSize, (const char*)dctxPtr->dict, (int)dctxPtr->dictSize);
+            {   int const decodedSize = LZ4_decompress_safe_usingDict(
+                        (const char*)selectedIn, (char*)dstPtr,
+                        (int)dctx->tmpInTarget, (int)dctx->maxBlockSize,
+                        (const char*)dctx->dict, (int)dctx->dictSize);
                 if (decodedSize < 0) return err0r(LZ4F_ERROR_GENERIC);   /* decompression failed */
-                if (dctxPtr->frameInfo.contentChecksumFlag) XXH32_update(&(dctxPtr->xxh), dstPtr, decodedSize);
-                if (dctxPtr->frameInfo.contentSize) dctxPtr->frameRemainingSize -= decodedSize;
+                if (dctx->frameInfo.contentChecksumFlag)
+                    XXH32_update(&(dctx->xxh), dstPtr, decodedSize);
+                if (dctx->frameInfo.contentSize)
+                    dctx->frameRemainingSize -= decodedSize;
 
                 /* dictionary management */
-                if (dctxPtr->frameInfo.blockMode==LZ4F_blockLinked)
-                    LZ4F_updateDict(dctxPtr, dstPtr, decodedSize, dstStart, 0);
+                if (dctx->frameInfo.blockMode==LZ4F_blockLinked)
+                    LZ4F_updateDict(dctx, dstPtr, decodedSize, dstStart, 0);
 
                 dstPtr += decodedSize;
-                dctxPtr->dStage = dstage_getCBlockSize;
+                dctx->dStage = dstage_getBlockHeader;
                 break;
             }
 
         case dstage_decodeCBlock_intoTmp:
             /* not enough place into dst : decode into tmpOut */
-            {   int (*decoder)(const char*, char*, int, int, const char*, int);
-                int decodedSize;
-
-                if (dctxPtr->frameInfo.blockMode == LZ4F_blockLinked)
-                    decoder = LZ4_decompress_safe_usingDict;
-                else
-                    decoder = LZ4F_decompress_safe;
-
-                /* ensure enough place for tmpOut */
-                if (dctxPtr->frameInfo.blockMode == LZ4F_blockLinked) {
-                    if (dctxPtr->dict == dctxPtr->tmpOutBuffer) {
-                        if (dctxPtr->dictSize > 128 KB) {
-                            memcpy(dctxPtr->tmpOutBuffer, dctxPtr->dict + dctxPtr->dictSize - 64 KB, 64 KB);
-                            dctxPtr->dictSize = 64 KB;
-                        }
-                        dctxPtr->tmpOut = dctxPtr->tmpOutBuffer + dctxPtr->dictSize;
-                    } else {  /* dict not within tmp */
-                        size_t reservedDictSpace = dctxPtr->dictSize;
-                        if (reservedDictSpace > 64 KB) reservedDictSpace = 64 KB;
-                        dctxPtr->tmpOut = dctxPtr->tmpOutBuffer + reservedDictSpace;
+
+            /* ensure enough place for tmpOut */
+            if (dctx->frameInfo.blockMode == LZ4F_blockLinked) {
+                if (dctx->dict == dctx->tmpOutBuffer) {
+                    if (dctx->dictSize > 128 KB) {
+                        memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - 64 KB, 64 KB);
+                        dctx->dictSize = 64 KB;
                     }
+                    dctx->tmpOut = dctx->tmpOutBuffer + dctx->dictSize;
+                } else {  /* dict not within tmp */
+                    size_t const reservedDictSpace = MIN(dctx->dictSize, 64 KB);
+                    dctx->tmpOut = dctx->tmpOutBuffer + reservedDictSpace;
                 }
+            }
 
-                /* Decode */
-                decodedSize = decoder((const char*)selectedIn, (char*)dctxPtr->tmpOut, (int)dctxPtr->tmpInTarget, (int)dctxPtr->maxBlockSize, (const char*)dctxPtr->dict, (int)dctxPtr->dictSize);
-                if (decodedSize < 0) return err0r(LZ4F_ERROR_decompressionFailed);   /* decompression failed */
-                if (dctxPtr->frameInfo.contentChecksumFlag) XXH32_update(&(dctxPtr->xxh), dctxPtr->tmpOut, decodedSize);
-                if (dctxPtr->frameInfo.contentSize) dctxPtr->frameRemainingSize -= decodedSize;
-                dctxPtr->tmpOutSize = decodedSize;
-                dctxPtr->tmpOutStart = 0;
-                dctxPtr->dStage = dstage_flushOut;
-                break;
+            /* Decode block */
+            {   int const decodedSize = LZ4_decompress_safe_usingDict(
+                        (const char*)selectedIn, (char*)dctx->tmpOut,
+                        (int)dctx->tmpInTarget, (int)dctx->maxBlockSize,
+                        (const char*)dctx->dict, (int)dctx->dictSize);
+                if (decodedSize < 0)  /* decompression failed */
+                    return err0r(LZ4F_ERROR_decompressionFailed);
+                if (dctx->frameInfo.contentChecksumFlag)
+                    XXH32_update(&(dctx->xxh), dctx->tmpOut, decodedSize);
+                if (dctx->frameInfo.contentSize)
+                    dctx->frameRemainingSize -= decodedSize;
+                dctx->tmpOutSize = decodedSize;
+                dctx->tmpOutStart = 0;
+                dctx->dStage = dstage_flushOut;
             }
+            /* fall-through */
 
         case dstage_flushOut:  /* flush decoded data from tmpOut to dstBuffer */
-            {   size_t sizeToCopy = dctxPtr->tmpOutSize - dctxPtr->tmpOutStart;
-                if (sizeToCopy > (size_t)(dstEnd-dstPtr)) sizeToCopy = dstEnd-dstPtr;
-                memcpy(dstPtr, dctxPtr->tmpOut + dctxPtr->tmpOutStart, sizeToCopy);
+            {   size_t const sizeToCopy = MIN(dctx->tmpOutSize - dctx->tmpOutStart, (size_t)(dstEnd-dstPtr));
+                memcpy(dstPtr, dctx->tmpOut + dctx->tmpOutStart, sizeToCopy);
 
                 /* dictionary management */
-                if (dctxPtr->frameInfo.blockMode==LZ4F_blockLinked)
-                    LZ4F_updateDict(dctxPtr, dstPtr, sizeToCopy, dstStart, 1);
+                if (dctx->frameInfo.blockMode==LZ4F_blockLinked)
+                    LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 1);
 
-                dctxPtr->tmpOutStart += sizeToCopy;
+                dctx->tmpOutStart += sizeToCopy;
                 dstPtr += sizeToCopy;
 
-                /* end of flush ? */
-                if (dctxPtr->tmpOutStart == dctxPtr->tmpOutSize) {
-                    dctxPtr->dStage = dstage_getCBlockSize;
+                if (dctx->tmpOutStart == dctx->tmpOutSize) { /* all flushed */
+                    dctx->dStage = dstage_getBlockHeader;  /* get next block */
                     break;
                 }
                 nextSrcSizeHint = BHSize;
@@ -1284,45 +1518,47 @@ size_t LZ4F_decompress(LZ4F_dctx* dctxPtr,
             }
 
         case dstage_getSuffix:
-            {   size_t const suffixSize = dctxPtr->frameInfo.contentChecksumFlag * 4;
-                if (dctxPtr->frameRemainingSize) return err0r(LZ4F_ERROR_frameSize_wrong);   /* incorrect frame size decoded */
+            {   size_t const suffixSize = dctx->frameInfo.contentChecksumFlag * 4;
+                if (dctx->frameRemainingSize)
+                    return err0r(LZ4F_ERROR_frameSize_wrong);   /* incorrect frame size decoded */
                 if (suffixSize == 0) {  /* frame completed */
                     nextSrcSizeHint = 0;
-                    dctxPtr->dStage = dstage_getHeader;
+                    LZ4F_resetDecompressionContext(dctx);
                     doAnotherStage = 0;
                     break;
                 }
                 if ((srcEnd - srcPtr) < 4) {  /* not enough size for entire CRC */
-                    dctxPtr->tmpInSize = 0;
-                    dctxPtr->dStage = dstage_storeSuffix;
+                    dctx->tmpInSize = 0;
+                    dctx->dStage = dstage_storeSuffix;
                 } else {
                     selectedIn = srcPtr;
                     srcPtr += 4;
                 }
             }
 
-            if (dctxPtr->dStage == dstage_storeSuffix)   /* can be skipped */
+            if (dctx->dStage == dstage_storeSuffix)   /* can be skipped */
         case dstage_storeSuffix:
             {
-                size_t sizeToCopy = 4 - dctxPtr->tmpInSize;
+                size_t sizeToCopy = 4 - dctx->tmpInSize;
                 if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr;
-                memcpy(dctxPtr->tmpIn + dctxPtr->tmpInSize, srcPtr, sizeToCopy);
+                memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
                 srcPtr += sizeToCopy;
-                dctxPtr->tmpInSize += sizeToCopy;
-                if (dctxPtr->tmpInSize < 4) { /* not enough input to read complete suffix */
-                    nextSrcSizeHint = 4 - dctxPtr->tmpInSize;
+                dctx->tmpInSize += sizeToCopy;
+                if (dctx->tmpInSize < 4) { /* not enough input to read complete suffix */
+                    nextSrcSizeHint = 4 - dctx->tmpInSize;
                     doAnotherStage=0;
                     break;
                 }
-                selectedIn = dctxPtr->tmpIn;
+                selectedIn = dctx->tmpIn;
             }
 
-        /* case dstage_checkSuffix: */   /* no direct call, to avoid scan-build warning */
+        /* case dstage_checkSuffix: */   /* no direct call, avoid scan-build warning */
             {   U32 const readCRC = LZ4F_readLE32(selectedIn);
-                U32 const resultCRC = XXH32_digest(&(dctxPtr->xxh));
-                if (readCRC != resultCRC) return err0r(LZ4F_ERROR_contentChecksum_invalid);
+                U32 const resultCRC = XXH32_digest(&(dctx->xxh));
+                if (readCRC != resultCRC)
+                    return err0r(LZ4F_ERROR_contentChecksum_invalid);
                 nextSrcSizeHint = 0;
-                dctxPtr->dStage = dstage_getHeader;
+                LZ4F_resetDecompressionContext(dctx);
                 doAnotherStage = 0;
                 break;
             }
@@ -1333,77 +1569,77 @@ size_t LZ4F_decompress(LZ4F_dctx* dctxPtr,
                 srcPtr += 4;
             } else {
                 /* not enough input to read cBlockSize field */
-                dctxPtr->tmpInSize = 4;
-                dctxPtr->tmpInTarget = 8;
-                dctxPtr->dStage = dstage_storeSFrameSize;
+                dctx->tmpInSize = 4;
+                dctx->tmpInTarget = 8;
+                dctx->dStage = dstage_storeSFrameSize;
             }
 
-            if (dctxPtr->dStage == dstage_storeSFrameSize)
+            if (dctx->dStage == dstage_storeSFrameSize)
         case dstage_storeSFrameSize:
             {
-                size_t sizeToCopy = dctxPtr->tmpInTarget - dctxPtr->tmpInSize;
-                if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr;
-                memcpy(dctxPtr->header + dctxPtr->tmpInSize, srcPtr, sizeToCopy);
+                size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize,
+                                             (size_t)(srcEnd - srcPtr) );
+                memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
                 srcPtr += sizeToCopy;
-                dctxPtr->tmpInSize += sizeToCopy;
-                if (dctxPtr->tmpInSize < dctxPtr->tmpInTarget) { /* not enough input to get full sBlockSize; wait for more */
-                    nextSrcSizeHint = dctxPtr->tmpInTarget - dctxPtr->tmpInSize;
+                dctx->tmpInSize += sizeToCopy;
+                if (dctx->tmpInSize < dctx->tmpInTarget) {
+                    /* not enough input to get full sBlockSize; wait for more */
+                    nextSrcSizeHint = dctx->tmpInTarget - dctx->tmpInSize;
                     doAnotherStage = 0;
                     break;
                 }
-                selectedIn = dctxPtr->header + 4;
+                selectedIn = dctx->header + 4;
             }
 
         /* case dstage_decodeSFrameSize: */   /* no direct access */
             {   size_t const SFrameSize = LZ4F_readLE32(selectedIn);
-                dctxPtr->frameInfo.contentSize = SFrameSize;
-                dctxPtr->tmpInTarget = SFrameSize;
-                dctxPtr->dStage = dstage_skipSkippable;
+                dctx->frameInfo.contentSize = SFrameSize;
+                dctx->tmpInTarget = SFrameSize;
+                dctx->dStage = dstage_skipSkippable;
                 break;
             }
 
         case dstage_skipSkippable:
-            {   size_t skipSize = dctxPtr->tmpInTarget;
-                if (skipSize > (size_t)(srcEnd-srcPtr)) skipSize = srcEnd-srcPtr;
+            {   size_t const skipSize = MIN(dctx->tmpInTarget, (size_t)(srcEnd-srcPtr));
                 srcPtr += skipSize;
-                dctxPtr->tmpInTarget -= skipSize;
+                dctx->tmpInTarget -= skipSize;
                 doAnotherStage = 0;
-                nextSrcSizeHint = dctxPtr->tmpInTarget;
-                if (nextSrcSizeHint) break;
-                dctxPtr->dStage = dstage_getHeader;
+                nextSrcSizeHint = dctx->tmpInTarget;
+                if (nextSrcSizeHint) break;  /* still more to skip */
+                LZ4F_resetDecompressionContext(dctx);
                 break;
             }
         }
     }
 
-    /* preserve dictionary within tmp if necessary */
-    if ( (dctxPtr->frameInfo.blockMode==LZ4F_blockLinked)
-        &&(dctxPtr->dict != dctxPtr->tmpOutBuffer)
-        &&(!decompressOptionsPtr->stableDst)
-        &&((unsigned)(dctxPtr->dStage-1) < (unsigned)(dstage_getSuffix-1))
-        )
+    /* preserve history within tmp if necessary */
+    if ( (dctx->frameInfo.blockMode==LZ4F_blockLinked)
+      && (dctx->dict != dctx->tmpOutBuffer)
+      && (dctx->dStage != dstage_getFrameHeader)
+      && (!decompressOptionsPtr->stableDst)
+      && ((unsigned)(dctx->dStage-1) < (unsigned)(dstage_getSuffix-1)) )
     {
-        if (dctxPtr->dStage == dstage_flushOut) {
-            size_t preserveSize = dctxPtr->tmpOut - dctxPtr->tmpOutBuffer;
-            size_t copySize = 64 KB - dctxPtr->tmpOutSize;
-            const BYTE* oldDictEnd = dctxPtr->dict + dctxPtr->dictSize - dctxPtr->tmpOutStart;
-            if (dctxPtr->tmpOutSize > 64 KB) copySize = 0;
+        if (dctx->dStage == dstage_flushOut) {
+            size_t preserveSize = dctx->tmpOut - dctx->tmpOutBuffer;
+            size_t copySize = 64 KB - dctx->tmpOutSize;
+            const BYTE* oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart;
+            if (dctx->tmpOutSize > 64 KB) copySize = 0;
             if (copySize > preserveSize) copySize = preserveSize;
 
-            memcpy(dctxPtr->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
+            memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
 
-            dctxPtr->dict = dctxPtr->tmpOutBuffer;
-            dctxPtr->dictSize = preserveSize + dctxPtr->tmpOutStart;
+            dctx->dict = dctx->tmpOutBuffer;
+            dctx->dictSize = preserveSize + dctx->tmpOutStart;
         } else {
-            size_t newDictSize = dctxPtr->dictSize;
-            const BYTE* oldDictEnd = dctxPtr->dict + dctxPtr->dictSize;
+            size_t newDictSize = dctx->dictSize;
+            const BYTE* oldDictEnd = dctx->dict + dctx->dictSize;
             if ((newDictSize) > 64 KB) newDictSize = 64 KB;
 
-            memcpy(dctxPtr->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize);
+            memcpy(dctx->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize);
 
-            dctxPtr->dict = dctxPtr->tmpOutBuffer;
-            dctxPtr->dictSize = newDictSize;
-            dctxPtr->tmpOut = dctxPtr->tmpOutBuffer + newDictSize;
+            dctx->dict = dctx->tmpOutBuffer;
+            dctx->dictSize = newDictSize;
+            dctx->tmpOut = dctx->tmpOutBuffer + newDictSize;
         }
     }
 
@@ -1411,3 +1647,23 @@ size_t LZ4F_decompress(LZ4F_dctx* dctxPtr,
     *dstSizePtr = (dstPtr - dstStart);
     return nextSrcSizeHint;
 }
+
+/*! LZ4F_decompress_usingDict() :
+ *  Same as LZ4F_decompress(), using a predefined dictionary.
+ *  Dictionary is used "in place", without any preprocessing.
+ *  It must remain accessible throughout the entire frame decoding.
+ */
+size_t LZ4F_decompress_usingDict(LZ4F_dctx* dctx,
+                       void* dstBuffer, size_t* dstSizePtr,
+                       const void* srcBuffer, size_t* srcSizePtr,
+                       const void* dict, size_t dictSize,
+                       const LZ4F_decompressOptions_t* decompressOptionsPtr)
+{
+    if (dctx->dStage <= dstage_init) {
+        dctx->dict = (const BYTE*)dict;
+        dctx->dictSize = dictSize;
+    }
+    return LZ4F_decompress(dctx, dstBuffer, dstSizePtr,
+                           srcBuffer, srcSizePtr,
+                           decompressOptionsPtr);
+}
diff --git a/lib/lz4frame.h b/lib/lz4frame.h
index a4a4ce6..88a6513 100644
--- a/lib/lz4frame.h
+++ b/lib/lz4frame.h
@@ -1,7 +1,7 @@
 /*
    LZ4 auto-framing library
    Header File
-   Copyright (C) 2011-2016, Yann Collet.
+   Copyright (C) 2011-2017, Yann Collet.
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
@@ -48,49 +48,68 @@ extern "C" {
 /* ---   Dependency   --- */
 #include <stddef.h>   /* size_t */
 
-/*-***************************************************************
-*  Compiler specifics
-*****************************************************************/
-/*!
-*  LZ4_DLL_EXPORT :
-*  Enable exporting of functions when building a Windows DLL
+
+/**
+  Introduction
+
+  lz4frame.h implements LZ4 frame specification (doc/lz4_Frame_format.md).
+  lz4frame.h provides frame compression functions that take care
+  of encoding standard metadata alongside LZ4-compressed blocks.
 */
+
+/*-***************************************************************
+ *  Compiler specifics
+ *****************************************************************/
+/*  LZ4_DLL_EXPORT :
+ *  Enable exporting of functions when building a Windows DLL
+ *  LZ4FLIB_API :
+ *  Control library symbols visibility.
+ */
 #if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
 #  define LZ4FLIB_API __declspec(dllexport)
 #elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1)
 #  define LZ4FLIB_API __declspec(dllimport)
+#elif defined(__GNUC__) && (__GNUC__ >= 4)
+#  define LZ4FLIB_API __attribute__ ((__visibility__ ("default")))
 #else
 #  define LZ4FLIB_API
 #endif
 
-#if defined(_MSC_VER)
-#  define LZ4F_DEPRECATE(x) x   /* __declspec(deprecated) x - only works with C++ */
-#elif defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 6))
-#  define LZ4F_DEPRECATE(x) x __attribute__((deprecated))
+#ifdef LZ4F_DISABLE_DEPRECATE_WARNINGS
+#  define LZ4F_DEPRECATE(x) x
 #else
-#  define LZ4F_DEPRECATE(x) x   /* no deprecation warning for this compiler */
+#  if defined(_MSC_VER)
+#    define LZ4F_DEPRECATE(x) x   /* __declspec(deprecated) x - only works with C++ */
+#  elif defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 6))
+#    define LZ4F_DEPRECATE(x) x __attribute__((deprecated))
+#  else
+#    define LZ4F_DEPRECATE(x) x   /* no deprecation warning for this compiler */
+#  endif
 #endif
 
 
 /*-************************************
-*  Error management
-**************************************/
+ *  Error management
+ **************************************/
 typedef size_t LZ4F_errorCode_t;
 
-LZ4FLIB_API unsigned    LZ4F_isError(LZ4F_errorCode_t code);
-LZ4FLIB_API const char* LZ4F_getErrorName(LZ4F_errorCode_t code);   /* return error code string; useful for debugging */
+LZ4FLIB_API unsigned    LZ4F_isError(LZ4F_errorCode_t code);   /**< tells if a `LZ4F_errorCode_t` function result is an error code */
+LZ4FLIB_API const char* LZ4F_getErrorName(LZ4F_errorCode_t code);   /**< return error code string; useful for debugging */
 
 
 /*-************************************
-*  Frame compression types
-**************************************/
-/* #define LZ4F_DISABLE_OBSOLETE_ENUMS */  /* uncomment to disable obsolete enums */
-#ifndef LZ4F_DISABLE_OBSOLETE_ENUMS
+ *  Frame compression types
+ **************************************/
+/* #define LZ4F_ENABLE_OBSOLETE_ENUMS   // uncomment to enable obsolete enums */
+#ifdef LZ4F_ENABLE_OBSOLETE_ENUMS
 #  define LZ4F_OBSOLETE_ENUM(x) , LZ4F_DEPRECATE(x) = LZ4F_##x
 #else
 #  define LZ4F_OBSOLETE_ENUM(x)
 #endif
 
+/* The larger the block size, the (slightly) better the compression ratio,
+ * though there are diminishing returns.
+ * Larger blocks also increase memory usage on both compression and decompression sides. */
 typedef enum {
     LZ4F_default=0,
     LZ4F_max64KB=4,
@@ -103,6 +122,9 @@ typedef enum {
     LZ4F_OBSOLETE_ENUM(max4MB)
 } LZ4F_blockSizeID_t;
 
+/* Linked blocks sharply reduce inefficiencies when using small blocks,
+ * they compress better.
+ * However, some LZ4 decoders are only compatible with independent blocks */
 typedef enum {
     LZ4F_blockLinked=0,
     LZ4F_blockIndependent
@@ -118,63 +140,70 @@ typedef enum {
 } LZ4F_contentChecksum_t;
 
 typedef enum {
+    LZ4F_noBlockChecksum=0,
+    LZ4F_blockChecksumEnabled
+} LZ4F_blockChecksum_t;
+
+typedef enum {
     LZ4F_frame=0,
     LZ4F_skippableFrame
     LZ4F_OBSOLETE_ENUM(skippableFrame)
 } LZ4F_frameType_t;
 
-#ifndef LZ4F_DISABLE_OBSOLETE_ENUMS
+#ifdef LZ4F_ENABLE_OBSOLETE_ENUMS
 typedef LZ4F_blockSizeID_t blockSizeID_t;
 typedef LZ4F_blockMode_t blockMode_t;
 typedef LZ4F_frameType_t frameType_t;
 typedef LZ4F_contentChecksum_t contentChecksum_t;
 #endif
 
-/* LZ4F_frameInfo_t :
- * makes it possible to supply detailed frame parameters to the stream interface.
- * It's not required to set all fields, as long as the structure was initially memset() to zero.
- * All reserved fields must be set to zero. */
+/*! LZ4F_frameInfo_t :
+ *  makes it possible to set or read frame parameters.
+ *  It's not required to set all fields, as long as the structure was initially memset() to zero.
+ *  For all fields, 0 sets it to default value */
 typedef struct {
-  LZ4F_blockSizeID_t     blockSizeID;           /* max64KB, max256KB, max1MB, max4MB ; 0 == default */
-  LZ4F_blockMode_t       blockMode;             /* blockLinked, blockIndependent ; 0 == default */
-  LZ4F_contentChecksum_t contentChecksumFlag;   /* noContentChecksum, contentChecksumEnabled ; 0 == default  */
-  LZ4F_frameType_t       frameType;             /* LZ4F_frame, skippableFrame ; 0 == default */
-  unsigned long long     contentSize;           /* Size of uncompressed (original) content ; 0 == unknown */
-  unsigned               reserved[2];           /* must be zero for forward compatibility */
+  LZ4F_blockSizeID_t     blockSizeID;          /* max64KB, max256KB, max1MB, max4MB ; 0 == default */
+  LZ4F_blockMode_t       blockMode;            /* LZ4F_blockLinked, LZ4F_blockIndependent ; 0 == default */
+  LZ4F_contentChecksum_t contentChecksumFlag;  /* if enabled, frame is terminated with a 32-bits checksum of decompressed data ; 0 == disabled (default)  */
+  LZ4F_frameType_t       frameType;            /* read-only field : LZ4F_frame or LZ4F_skippableFrame */
+  unsigned long long     contentSize;          /* Size of uncompressed content ; 0 == unknown */
+  unsigned               dictID;               /* Dictionary ID, sent by the compressor to help decoder select the correct dictionary; 0 == no dictID provided */
+  LZ4F_blockChecksum_t   blockChecksumFlag;    /* if enabled, each block is followed by a checksum of block's compressed data ; 0 == disabled (default)  */
 } LZ4F_frameInfo_t;
 
-/* LZ4F_preferences_t :
- * makes it possible to supply detailed compression parameters to the stream interface.
- * It's not required to set all fields, as long as the structure was initially memset() to zero.
- * All reserved fields must be set to zero. */
+/*! LZ4F_preferences_t :
+ *  makes it possible to supply detailed compression parameters to the stream interface.
+ *  It's not required to set all fields, as long as the structure was initially memset() to zero.
+ *  All reserved fields must be set to zero. */
 typedef struct {
   LZ4F_frameInfo_t frameInfo;
-  int      compressionLevel;       /* 0 == default (fast mode); values above 16 count as 16; values below 0 count as 0 */
-  unsigned autoFlush;              /* 1 == always flush (reduce usage of tmp buffer) */
+  int      compressionLevel;       /* 0 == default (fast mode); values above LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values below 0 trigger "fast acceleration", proportional to value */
+  unsigned autoFlush;              /* 1 == always flush, to reduce usage of internal buffers */
   unsigned reserved[4];            /* must be zero for forward compatibility */
 } LZ4F_preferences_t;
 
+LZ4FLIB_API int LZ4F_compressionLevel_max(void);
+
 
 /*-*********************************
 *  Simple compression function
 ***********************************/
-/*!LZ4F_compressFrameBound() :
- * Returns the maximum possible size of a frame compressed with LZ4F_compressFrame() given srcSize content and preferences.
- * Note : this result is only usable with LZ4F_compressFrame(), not with multi-segments compression.
+/*! LZ4F_compressFrameBound() :
+ *  Returns the maximum possible size of a frame compressed with LZ4F_compressFrame() given srcSize content and preferences.
+ *  Note : this result is only usable with LZ4F_compressFrame(), not with multi-segments compression.
  */
 LZ4FLIB_API size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr);
 
-/*!LZ4F_compressFrame() :
- * Compress an entire srcBuffer into a valid LZ4 frame, as defined by specification v1.5.1
- * An important rule is that dstBuffer MUST be large enough (dstCapacity) to store the result in worst case situation.
- * This value is supplied by LZ4F_compressFrameBound().
- * If this condition is not respected, LZ4F_compressFrame() will fail (result is an errorCode).
- * The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default.
+/*! LZ4F_compressFrame() :
+ *  Compress an entire srcBuffer into a valid LZ4 frame.
+ *  dstCapacity MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
+ *  The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default.
  * @return : number of bytes written into dstBuffer.
  *           or an error code if it fails (can be tested using LZ4F_isError())
  */
-LZ4FLIB_API size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_preferences_t* preferencesPtr);
-
+LZ4FLIB_API size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity,
+                                const void* srcBuffer, size_t srcSize,
+                                const LZ4F_preferences_t* preferencesPtr);
 
 
 /*-***********************************
@@ -188,44 +217,45 @@ typedef struct {
   unsigned reserved[3];
 } LZ4F_compressOptions_t;
 
-/* Resource Management */
+/*---   Resource Management   ---*/
 
 #define LZ4F_VERSION 100
 LZ4FLIB_API unsigned LZ4F_getVersion(void);
-LZ4FLIB_API LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_cctx** cctxPtr, unsigned version);
-LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
-/* LZ4F_createCompressionContext() :
+/*! LZ4F_createCompressionContext() :
  * The first thing to do is to create a compressionContext object, which will be used in all compression operations.
- * This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure.
+ * This is achieved using LZ4F_createCompressionContext(), which takes as argument a version.
  * The version provided MUST be LZ4F_VERSION. It is intended to track potential version mismatch, notably when using DLL.
  * The function will provide a pointer to a fully allocated LZ4F_cctx object.
  * If @return != zero, there was an error during context creation.
  * Object can release its memory using LZ4F_freeCompressionContext();
  */
+LZ4FLIB_API LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_cctx** cctxPtr, unsigned version);
+LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
 
 
-/* Compression */
+/*----    Compression    ----*/
 
-#define LZ4F_HEADER_SIZE_MAX 15
-LZ4FLIB_API size_t LZ4F_compressBegin(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_preferences_t* prefsPtr);
-/* LZ4F_compressBegin() :
- * will write the frame header into dstBuffer.
- * dstCapacity must be large enough to store the header. Maximum header size is LZ4F_HEADER_SIZE_MAX bytes.
+#define LZ4F_HEADER_SIZE_MAX 19
+/*! LZ4F_compressBegin() :
+ *  will write the frame header into dstBuffer.
+ *  dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
  * `prefsPtr` is optional : you can provide NULL as argument, all preferences will then be set to default.
  * @return : number of bytes written into dstBuffer for the header
  *           or an error code (which can be tested using LZ4F_isError())
  */
+LZ4FLIB_API size_t LZ4F_compressBegin(LZ4F_cctx* cctx,
+                                      void* dstBuffer, size_t dstCapacity,
+                                      const LZ4F_preferences_t* prefsPtr);
 
-LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr);
-/* LZ4F_compressBound() :
+/*! LZ4F_compressBound() :
  * Provides dstCapacity given a srcSize to guarantee operation success in worst case situations.
  * prefsPtr is optional : you can provide NULL as argument, preferences will be set to cover worst case scenario.
  * Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers.
  * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
  */
+LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr);
 
-LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* cOptPtr);
-/* LZ4F_compressUpdate() :
+/*! LZ4F_compressUpdate() :
  * LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
  * An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations.
  * This value is provided by LZ4F_compressBound().
@@ -235,9 +265,9 @@ LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, void* dstBuffer, size_t
  * @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
  *           or an error code if it fails (which can be tested using LZ4F_isError())
  */
+LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* cOptPtr);
 
-LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
-/* LZ4F_flush() :
+/*! LZ4F_flush() :
  * When data must be generated and sent immediately, without waiting for a block to be completely filled,
  * it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
  * `dstCapacity` must be large enough to ensure the operation will be successful.
@@ -245,17 +275,18 @@ LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapaci
  * @return : number of bytes written into dstBuffer (it can be zero, which means there was no data stored within cctx)
  *           or an error code if it fails (which can be tested using LZ4F_isError())
  */
+LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
 
-LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
-/* LZ4F_compressEnd() :
- * To properly finish an LZ4 frame, invoke LZ4F_compressEnd().
- * It will flush whatever data remained within `cctx` (like LZ4_flush())
- * and properly finalize the frame, with an endMark and a checksum.
+/*! LZ4F_compressEnd() :
+ *  To properly finish an LZ4 frame, invoke LZ4F_compressEnd().
+ *  It will flush whatever data remained within `cctx` (like LZ4_flush())
+ *  and properly finalize the frame, with an endMark and a checksum.
  * `cOptPtr` is optional : NULL can be provided, in which case all options will be set to default.
  * @return : number of bytes written into dstBuffer (necessarily >= 4 (endMark), or 8 if optional frame checksum is enabled)
  *           or an error code if it fails (which can be tested using LZ4F_isError())
- * A successful call to LZ4F_compressEnd() makes `cctx` available again for another compression task.
+ *  A successful call to LZ4F_compressEnd() makes `cctx` available again for another compression task.
  */
+LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
 
 
 /*-*********************************
@@ -265,66 +296,78 @@ typedef struct LZ4F_dctx_s LZ4F_dctx;   /* incomplete type */
 typedef LZ4F_dctx* LZ4F_decompressionContext_t;   /* compatibility with previous API versions */
 
 typedef struct {
-  unsigned stableDst;       /* guarantee that decompressed data will still be there on next function calls (avoid storage into tmp buffers) */
-  unsigned reserved[3];
+  unsigned stableDst;    /* pledge that at least 64KB+64Bytes of previously decompressed data remain unmodifed where it was decoded. This optimization skips storage operations in tmp buffers */
+  unsigned reserved[3];  /* must be set to zero for forward compatibility */
 } LZ4F_decompressOptions_t;
 
 
 /* Resource management */
 
 /*!LZ4F_createDecompressionContext() :
- * Create an LZ4F_decompressionContext_t object, which will be used to track all decompression operations.
- * The version provided MUST be LZ4F_VERSION. It is intended to track potential breaking differences between different versions.
- * The function will provide a pointer to a fully allocated and initialized LZ4F_decompressionContext_t object.
+ * Create an LZ4F_dctx object, to track all decompression operations.
+ * The version provided MUST be LZ4F_VERSION.
+ * The function provides a pointer to an allocated and initialized LZ4F_dctx object.
  * The result is an errorCode, which can be tested using LZ4F_isError().
  * dctx memory can be released using LZ4F_freeDecompressionContext();
  * The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released.
  * That is, it should be == 0 if decompression has been completed fully and correctly.
  */
 LZ4FLIB_API LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** dctxPtr, unsigned version);
-LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* const dctx);
+LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
 
 
-/*======   Decompression   ======*/
+/*-***********************************
+*  Streaming decompression functions
+*************************************/
 
-/*!LZ4F_getFrameInfo() :
- * This function decodes frame header information (such as max blockSize, frame checksum, etc.).
- * Its usage is optional. The objective is to extract frame header information, typically for allocation purposes.
- * A header size is variable and can length from 7 to 15 bytes. It's possible to provide more input bytes than that.
- * The number of bytes consumed from srcBuffer will be updated within *srcSizePtr (necessarily <= original value).
- * Decompression must resume from this point (srcBuffer + *srcSizePtr).
- * Note that LZ4F_getFrameInfo() can also be used anytime *after* decompression is started, in which case 0 input byte can be enough.
- * Frame header info is *copied into* an already allocated LZ4F_frameInfo_t structure.
+/*! LZ4F_getFrameInfo() :
+ *  This function extracts frame parameters (max blockSize, dictID, etc.).
+ *  Its usage is optional.
+ *  Extracted information is typically useful for allocation and dictionary.
+ *  This function works in 2 situations :
+ *   - At the beginning of a new frame, in which case
+ *     it will decode information from `srcBuffer`, starting the decoding process.
+ *     Input size must be large enough to successfully decode the entire frame header.
+ *     Frame header size is variable, but is guaranteed to be <= LZ4F_HEADER_SIZE_MAX bytes.
+ *     It's allowed to provide more input data than this minimum.
+ *   - After decoding has been started.
+ *     In which case, no input is read, frame parameters are extracted from dctx.
+ *   - If decoding has barely started, but not yet extracted information from header,
+ *     LZ4F_getFrameInfo() will fail.
+ *  The number of bytes consumed from srcBuffer will be updated within *srcSizePtr (necessarily <= original value).
+ *  Decompression must resume from (srcBuffer + *srcSizePtr).
  * @return : an hint about how many srcSize bytes LZ4F_decompress() expects for next call,
- *           or an error code which can be tested using LZ4F_isError()
- *           (typically, when there is not enough src bytes to fully decode the frame header)
+ *           or an error code which can be tested using LZ4F_isError().
+ *  note 1 : in case of error, dctx is not modified. Decoding operation can resume from beginning safely.
+ *  note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure.
  */
 LZ4FLIB_API size_t LZ4F_getFrameInfo(LZ4F_dctx* dctx,
                                      LZ4F_frameInfo_t* frameInfoPtr,
                                      const void* srcBuffer, size_t* srcSizePtr);
 
-/*!LZ4F_decompress() :
- * Call this function repetitively to regenerate data compressed within `srcBuffer`.
- * The function will attempt to decode up to *srcSizePtr bytes from srcBuffer, into dstBuffer of capacity *dstSizePtr.
+/*! LZ4F_decompress() :
+ *  Call this function repetitively to regenerate compressed data from `srcBuffer`.
+ *  The function will attempt to decode up to *srcSizePtr bytes from srcBuffer, into dstBuffer of capacity *dstSizePtr.
  *
- * The number of bytes regenerated into dstBuffer will be provided within *dstSizePtr (necessarily <= original value).
+ *  The number of bytes regenerated into dstBuffer is provided within *dstSizePtr (necessarily <= original value).
  *
- * The number of bytes read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value).
- * Number of bytes read can be < number of bytes provided, meaning there is some more data to decode.
- * It typically happens when dstBuffer is not large enough to contain all decoded data.
- * Remaining data will have to be presented again in a subsequent invocation.
+ *  The number of bytes consumed from srcBuffer is provided within *srcSizePtr (necessarily <= original value).
+ *  Number of bytes consumed can be < number of bytes provided.
+ *  It typically happens when dstBuffer is not large enough to contain all decoded data.
+ *  Unconsumed source data must be presented again in subsequent invocations.
  *
  * `dstBuffer` content is expected to be flushed between each invocation, as its content will be overwritten.
- * `dstBuffer` can be changed at will between each consecutive function invocation.
+ * `dstBuffer` itself can be changed at will between each consecutive function invocation.
  *
- * @return is an hint of how many `srcSize` bytes LZ4F_decompress() expects for next call.
- * Schematically, it's the size of the current (or remaining) compressed block + header of next block.
- * Respecting the hint provides some boost to performance, since it does skip intermediate buffers.
- * This is just a hint though, it's always possible to provide any srcSize.
- * When a frame is fully decoded, @return will be 0 (no more data expected).
- * If decompression failed, @return is an error code, which can be tested using LZ4F_isError().
+ * @return : an hint of how many `srcSize` bytes LZ4F_decompress() expects for next call.
+ *  Schematically, it's the size of the current (or remaining) compressed block + header of next block.
+ *  Respecting the hint provides some small speed benefit, because it skips intermediate buffers.
+ *  This is just a hint though, it's always possible to provide any srcSize.
+ *  When a frame is fully decoded, @return will be 0 (no more data expected).
+ *  If decompression failed, @return is an error code, which can be tested using LZ4F_isError().
  *
- * After a frame is fully decoded, dctx can be used again to decompress another frame.
+ *  After a frame is fully decoded, dctx can be used again to decompress another frame.
+ *  After a decompression error, use LZ4F_resetDecompressionContext() before re-using dctx, to return to clean state.
  */
 LZ4FLIB_API size_t LZ4F_decompress(LZ4F_dctx* dctx,
                                    void* dstBuffer, size_t* dstSizePtr,
@@ -332,6 +375,14 @@ LZ4FLIB_API size_t LZ4F_decompress(LZ4F_dctx* dctx,
                                    const LZ4F_decompressOptions_t* dOptPtr);
 
 
+/*! LZ4F_resetDecompressionContext() : v1.8.0
+ *  In case of an error, the context is left in "undefined" state.
+ *  In which case, it's necessary to reset it, before re-using it.
+ *  This method can also be used to abruptly stop an unfinished decompression,
+ *  and start a new one using the same context. */
+LZ4FLIB_API void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx);   /* always successful */
+
+
 
 #if defined (__cplusplus)
 }
diff --git a/lib/lz4frame_static.h b/lib/lz4frame_static.h
index f2228a5..1899f8e 100644
--- a/lib/lz4frame_static.h
+++ b/lib/lz4frame_static.h
@@ -43,7 +43,7 @@ extern "C" {
 /* lz4frame_static.h should be used solely in the context of static linking.
  * It contains definitions which are not stable and may change in the future.
  * Never use it in the context of DLL linking.
- * */
+ */
 
 
 /* ---   Dependency   --- */
@@ -52,29 +52,90 @@ extern "C" {
 
 /* ---   Error List   --- */
 #define LZ4F_LIST_ERRORS(ITEM) \
-        ITEM(OK_NoError) ITEM(ERROR_GENERIC) \
-        ITEM(ERROR_maxBlockSize_invalid) ITEM(ERROR_blockMode_invalid) ITEM(ERROR_contentChecksumFlag_invalid) \
+        ITEM(OK_NoError) \
+        ITEM(ERROR_GENERIC) \
+        ITEM(ERROR_maxBlockSize_invalid) \
+        ITEM(ERROR_blockMode_invalid) \
+        ITEM(ERROR_contentChecksumFlag_invalid) \
         ITEM(ERROR_compressionLevel_invalid) \
-        ITEM(ERROR_headerVersion_wrong) ITEM(ERROR_blockChecksum_unsupported) ITEM(ERROR_reservedFlag_set) \
+        ITEM(ERROR_headerVersion_wrong) \
+        ITEM(ERROR_blockChecksum_invalid) \
+        ITEM(ERROR_reservedFlag_set) \
         ITEM(ERROR_allocation_failed) \
-        ITEM(ERROR_srcSize_tooLarge) ITEM(ERROR_dstMaxSize_tooSmall) \
-        ITEM(ERROR_frameHeader_incomplete) ITEM(ERROR_frameType_unknown) ITEM(ERROR_frameSize_wrong) \
+        ITEM(ERROR_srcSize_tooLarge) \
+        ITEM(ERROR_dstMaxSize_tooSmall) \
+        ITEM(ERROR_frameHeader_incomplete) \
+        ITEM(ERROR_frameType_unknown) \
+        ITEM(ERROR_frameSize_wrong) \
         ITEM(ERROR_srcPtr_wrong) \
         ITEM(ERROR_decompressionFailed) \
-        ITEM(ERROR_headerChecksum_invalid) ITEM(ERROR_contentChecksum_invalid) \
+        ITEM(ERROR_headerChecksum_invalid) \
+        ITEM(ERROR_contentChecksum_invalid) \
+        ITEM(ERROR_frameDecoding_alreadyStarted) \
         ITEM(ERROR_maxCode)
 
-#define LZ4F_DISABLE_OLD_ENUMS   /* comment to enable deprecated enums */
-#ifndef LZ4F_DISABLE_OLD_ENUMS
-#  define LZ4F_GENERATE_ENUM(ENUM) LZ4F_##ENUM, ENUM = LZ4F_##ENUM,
-#else
-#  define LZ4F_GENERATE_ENUM(ENUM) LZ4F_##ENUM,
-#endif
-typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) } LZ4F_errorCodes;  /* enum is exposed, to handle specific errors; compare function result to -enum value */
+#define LZ4F_GENERATE_ENUM(ENUM) LZ4F_##ENUM,
+
+/* enum list is exposed, to handle specific errors */
+typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) } LZ4F_errorCodes;
 
 LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult);
 
 
+
+/**********************************
+ *  Bulk processing dictionary API
+ *********************************/
+typedef struct LZ4F_CDict_s LZ4F_CDict;
+
+/*! LZ4_createCDict() :
+ *  When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
+ *  LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
+ *  LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
+ * `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict */
+LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize);
+void        LZ4F_freeCDict(LZ4F_CDict* CDict);
+
+
+/*! LZ4_compressFrame_usingCDict() :
+ *  Compress an entire srcBuffer into a valid LZ4 frame using a digested Dictionary.
+ *  If cdict==NULL, compress without a dictionary.
+ *  dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
+ *  If this condition is not respected, function will fail (@return an errorCode).
+ *  The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
+ *  but it's not recommended, as it's the only way to provide dictID in the frame header.
+ * @return : number of bytes written into dstBuffer.
+ *           or an error code if it fails (can be tested using LZ4F_isError()) */
+size_t LZ4F_compressFrame_usingCDict(void* dst, size_t dstCapacity,
+                               const void* src, size_t srcSize,
+                               const LZ4F_CDict* cdict,
+                               const LZ4F_preferences_t* preferencesPtr);
+
+
+/*! LZ4F_compressBegin_usingCDict() :
+ *  Inits streaming dictionary compression, and writes the frame header into dstBuffer.
+ *  dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
+ * `prefsPtr` is optional : you may provide NULL as argument,
+ *  however, it's the only way to provide dictID in the frame header.
+ * @return : number of bytes written into dstBuffer for the header,
+ *           or an error code (which can be tested using LZ4F_isError()) */
+size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctx,
+                                     void* dstBuffer, size_t dstCapacity,
+                                     const LZ4F_CDict* cdict,
+                                     const LZ4F_preferences_t* prefsPtr);
+
+
+/*! LZ4F_decompress_usingDict() :
+ *  Same as LZ4F_decompress(), using a predefined dictionary.
+ *  Dictionary is used "in place", without any preprocessing.
+ *  It must remain accessible throughout the entire frame decoding. */
+size_t LZ4F_decompress_usingDict(LZ4F_dctx* dctxPtr,
+                       void* dstBuffer, size_t* dstSizePtr,
+                       const void* srcBuffer, size_t* srcSizePtr,
+                       const void* dict, size_t dictSize,
+                       const LZ4F_decompressOptions_t* decompressOptionsPtr);
+
+
 #if defined (__cplusplus)
 }
 #endif
diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index 5d4ea3e..22eb071 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -1,6 +1,6 @@
 /*
     LZ4 HC - High Compression Mode of LZ4
-    Copyright (C) 2011-2016, Yann Collet.
+    Copyright (C) 2011-2017, Yann Collet.
 
     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
@@ -38,54 +38,42 @@
 *  Tuning Parameter
 ***************************************/
 
-/*!
- * HEAPMODE :
- * Select how default compression function will allocate workplace memory,
- * in stack (0:fastest), or in heap (1:requires malloc()).
- * Since workplace is rather large, heap mode is recommended.
+/*! HEAPMODE :
+ *  Select how default compression function will allocate workplace memory,
+ *  in stack (0:fastest), or in heap (1:requires malloc()).
+ *  Since workplace is rather large, heap mode is recommended.
  */
 #ifndef LZ4HC_HEAPMODE
 #  define LZ4HC_HEAPMODE 1
 #endif
 
 
-/* *************************************
-*  Dependency
-***************************************/
+/*===    Dependency    ===*/
 #include "lz4hc.h"
 
 
-/* *************************************
-*  Local Compiler Options
-***************************************/
+/*===   Common LZ4 definitions   ===*/
 #if defined(__GNUC__)
 #  pragma GCC diagnostic ignored "-Wunused-function"
 #endif
-
 #if defined (__clang__)
 #  pragma clang diagnostic ignored "-Wunused-function"
 #endif
 
-
-/* *************************************
-*  Common LZ4 definition
-***************************************/
 #define LZ4_COMMONDEFS_ONLY
-#include "lz4.c"
+#include "lz4.c"   /* LZ4_count, constants, mem */
 
 
-/* *************************************
-*  Local Constants
-***************************************/
+/*===   Constants   ===*/
 #define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
 
 
-/**************************************
-*  Local Macros
-**************************************/
-#define HASH_FUNCTION(i)       (((i) * 2654435761U) >> ((MINMATCH*8)-LZ4HC_HASH_LOG))
-#define DELTANEXTMAXD(p)       chainTable[(p) & LZ4HC_MAXD_MASK]    /* flexible, LZ4HC_MAXD dependent */
-#define DELTANEXTU16(p)        chainTable[(U16)(p)]   /* faster */
+/*===   Macros   ===*/
+#define MIN(a,b)   ( (a) < (b) ? (a) : (b) )
+#define MAX(a,b)   ( (a) > (b) ? (a) : (b) )
+#define HASH_FUNCTION(i)         (((i) * 2654435761U) >> ((MINMATCH*8)-LZ4HC_HASH_LOG))
+#define DELTANEXTMAXD(p)         chainTable[(p) & LZ4HC_MAXD_MASK]    /* flexible, LZ4HC_MAXD dependent */
+#define DELTANEXTU16(table, pos) table[(U16)(pos)]   /* faster */
 
 static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); }
 
@@ -120,7 +108,7 @@ FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip)
         U32 const h = LZ4HC_hashPtr(base+idx);
         size_t delta = idx - hashTable[h];
         if (delta>MAX_DISTANCE) delta = MAX_DISTANCE;
-        DELTANEXTU16(idx) = (U16)delta;
+        DELTANEXTU16(chainTable, idx) = (U16)delta;
         hashTable[h] = idx;
         idx++;
     }
@@ -129,8 +117,8 @@ FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip)
 }
 
 
-FORCE_INLINE int LZ4HC_InsertAndFindBestMatch (LZ4HC_CCtx_internal* hc4,   /* Index table will be updated */
-                                               const BYTE* ip, const BYTE* const iLimit,
+FORCE_INLINE int LZ4HC_InsertAndFindBestMatch (LZ4HC_CCtx_internal* const hc4,   /* Index table will be updated */
+                                               const BYTE* const ip, const BYTE* const iLimit,
                                                const BYTE** matchpos,
                                                const int maxNbAttempts)
 {
@@ -141,8 +129,8 @@ FORCE_INLINE int LZ4HC_InsertAndFindBestMatch (LZ4HC_CCtx_internal* hc4,   /* In
     const U32 dictLimit = hc4->dictLimit;
     const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - (64 KB - 1);
     U32 matchIndex;
-    int nbAttempts=maxNbAttempts;
-    size_t ml=0;
+    int nbAttempts = maxNbAttempts;
+    size_t ml = 0;
 
     /* HC4 match finder */
     LZ4HC_Insert(hc4, ip);
@@ -152,8 +140,8 @@ FORCE_INLINE int LZ4HC_InsertAndFindBestMatch (LZ4HC_CCtx_internal* hc4,   /* In
         nbAttempts--;
         if (matchIndex >= dictLimit) {
             const BYTE* const match = base + matchIndex;
-            if (*(match+ml) == *(ip+ml)
-                && (LZ4_read32(match) == LZ4_read32(ip)))
+            if ( (*(match+ml) == *(ip+ml))   /* can be longer */
+               && (LZ4_read32(match) == LZ4_read32(ip)) )
             {
                 size_t const mlt = LZ4_count(ip+MINMATCH, match+MINMATCH, iLimit) + MINMATCH;
                 if (mlt > ml) { ml = mlt; *matchpos = match; }
@@ -170,7 +158,7 @@ FORCE_INLINE int LZ4HC_InsertAndFindBestMatch (LZ4HC_CCtx_internal* hc4,   /* In
                 if (mlt > ml) { ml = mlt; *matchpos = base + matchIndex; }   /* virtual matchpos */
             }
         }
-        matchIndex -= DELTANEXTU16(matchIndex);
+        matchIndex -= DELTANEXTU16(chainTable, matchIndex);
     }
 
     return (int)ml;
@@ -194,9 +182,9 @@ FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch (
     const BYTE* const lowPrefixPtr = base + dictLimit;
     const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - (64 KB - 1);
     const BYTE* const dictBase = hc4->dictBase;
-    U32   matchIndex;
+    int const delta = (int)(ip-iLowLimit);
     int nbAttempts = maxNbAttempts;
-    int delta = (int)(ip-iLowLimit);
+    U32 matchIndex;
 
 
     /* First Match */
@@ -206,30 +194,29 @@ FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch (
     while ((matchIndex>=lowLimit) && (nbAttempts)) {
         nbAttempts--;
         if (matchIndex >= dictLimit) {
-            const BYTE* matchPtr = base + matchIndex;
+            const BYTE* const matchPtr = base + matchIndex;
             if (*(iLowLimit + longest) == *(matchPtr - delta + longest)) {
                 if (LZ4_read32(matchPtr) == LZ4_read32(ip)) {
                     int mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
                     int back = 0;
 
-                    while ((ip+back > iLowLimit)
-                           && (matchPtr+back > lowPrefixPtr)
-                           && (ip[back-1] == matchPtr[back-1]))
+                    while ( (ip+back > iLowLimit)
+                         && (matchPtr+back > lowPrefixPtr)
+                         && (ip[back-1] == matchPtr[back-1])) {
                             back--;
+                    }
 
                     mlt -= back;
 
                     if (mlt > longest) {
-                        longest = (int)mlt;
+                        longest = mlt;
                         *matchpos = matchPtr+back;
                         *startpos = ip+back;
-                    }
-                }
-            }
+            }   }   }
         } else {
             const BYTE* const matchPtr = dictBase + matchIndex;
             if (LZ4_read32(matchPtr) == LZ4_read32(ip)) {
-                size_t mlt;
+                int mlt;
                 int back=0;
                 const BYTE* vLimit = ip + (dictLimit - matchIndex);
                 if (vLimit > iHighLimit) vLimit = iHighLimit;
@@ -238,45 +225,57 @@ FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch (
                     mlt += LZ4_count(ip+mlt, base+dictLimit, iHighLimit);
                 while ((ip+back > iLowLimit) && (matchIndex+back > lowLimit) && (ip[back-1] == matchPtr[back-1])) back--;
                 mlt -= back;
-                if ((int)mlt > longest) { longest = (int)mlt; *matchpos = base + matchIndex + back; *startpos = ip+back; }
+                if (mlt > longest) { longest = mlt; *matchpos = base + matchIndex + back; *startpos = ip+back; }
             }
         }
-        matchIndex -= DELTANEXTU16(matchIndex);
+        matchIndex -= DELTANEXTU16(chainTable, matchIndex);
     }
 
     return longest;
 }
 
 
-typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
+typedef enum {
+    noLimit = 0,
+    limitedOutput = 1,
+    limitedDestSize = 2,
+} limitedOutput_directive;
 
-#define LZ4HC_DEBUG 0
-#if LZ4HC_DEBUG
-static unsigned debug = 0;
+#ifndef LZ4HC_DEBUG
+#  define LZ4HC_DEBUG 0
 #endif
 
+/* LZ4HC_encodeSequence() :
+ * @return : 0 if ok,
+ *           1 if buffer issue detected */
 FORCE_INLINE int LZ4HC_encodeSequence (
     const BYTE** ip,
     BYTE** op,
     const BYTE** anchor,
     int matchLength,
     const BYTE* const match,
-    limitedOutput_directive limitedOutputBuffer,
+    limitedOutput_directive limit,
     BYTE* oend)
 {
-    int length;
-    BYTE* token;
+    size_t length;
+    BYTE* const token = (*op)++;
 
 #if LZ4HC_DEBUG
-    if (debug) printf("literal : %u  --  match : %u  --  offset : %u\n", (U32)(*ip - *anchor), (U32)matchLength, (U32)(*ip-match));
+    printf("literal : %u  --  match : %u  --  offset : %u\n",
+           (U32)(*ip - *anchor), (U32)matchLength, (U32)(*ip-match));
 #endif
 
     /* Encode Literal length */
-    length = (int)(*ip - *anchor);
-    token = (*op)++;
-    if ((limitedOutputBuffer) && ((*op + (length>>8) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1;   /* Check output limit */
-    if (length>=(int)RUN_MASK) { int len; *token=(RUN_MASK<<ML_BITS); len = length-RUN_MASK; for(; len > 254 ; len-=255) *(*op)++ = 255;  *(*op)++ = (BYTE)len; }
-    else *token = (BYTE)(length<<ML_BITS);
+    length = (size_t)(*ip - *anchor);
+    if ((limit) && ((*op + (length >> 8) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1;   /* Check output limit */
+    if (length >= RUN_MASK) {
+        size_t len = length - RUN_MASK;
+        *token = (RUN_MASK << ML_BITS);
+        for(; len >= 255 ; len -= 255) *(*op)++ = 255;
+        *(*op)++ = (BYTE)len;
+    } else {
+        *token = (BYTE)(length << ML_BITS);
+    }
 
     /* Copy Literals */
     LZ4_wildCopy(*op, *anchor, (*op) + length);
@@ -286,13 +285,13 @@ FORCE_INLINE int LZ4HC_encodeSequence (
     LZ4_writeLE16(*op, (U16)(*ip-match)); *op += 2;
 
     /* Encode MatchLength */
-    length = (int)(matchLength-MINMATCH);
-    if ((limitedOutputBuffer) && (*op + (length>>8) + (1 + LASTLITERALS) > oend)) return 1;   /* Check output limit */
-    if (length>=(int)ML_MASK) {
+    length = (size_t)(matchLength - MINMATCH);
+    if ((limit) && (*op + (length >> 8) + (1 + LASTLITERALS) > oend)) return 1;   /* Check output limit */
+    if (length >= ML_MASK) {
         *token += ML_MASK;
         length -= ML_MASK;
-        for(; length > 509 ; length-=510) { *(*op)++ = 255; *(*op)++ = 255; }
-        if (length > 254) { length-=255; *(*op)++ = 255; }
+        for(; length >= 510 ; length -= 510) { *(*op)++ = 255; *(*op)++ = 255; }
+        if (length >= 255) { length -= 255; *(*op)++ = 255; }
         *(*op)++ = (BYTE)length;
     } else {
         *token += (BYTE)(length);
@@ -305,26 +304,31 @@ FORCE_INLINE int LZ4HC_encodeSequence (
     return 0;
 }
 
+/* btopt */
 #include "lz4opt.h"
 
+
 static int LZ4HC_compress_hashChain (
     LZ4HC_CCtx_internal* const ctx,
     const char* const source,
     char* const dest,
-    int const inputSize,
+    int* srcSizePtr,
     int const maxOutputSize,
     unsigned maxNbAttempts,
     limitedOutput_directive limit
     )
 {
+    const int inputSize = *srcSizePtr;
+
     const BYTE* ip = (const BYTE*) source;
     const BYTE* anchor = ip;
     const BYTE* const iend = ip + inputSize;
     const BYTE* const mflimit = iend - MFLIMIT;
     const BYTE* const matchlimit = (iend - LASTLITERALS);
 
+    BYTE* optr = (BYTE*) dest;
     BYTE* op = (BYTE*) dest;
-    BYTE* const oend = op + maxOutputSize;
+    BYTE* oend = op + maxOutputSize;
 
     int   ml, ml2, ml3, ml0;
     const BYTE* ref = NULL;
@@ -336,7 +340,13 @@ static int LZ4HC_compress_hashChain (
     const BYTE* ref0;
 
     /* init */
+    *srcSizePtr = 0;
+    if (limit == limitedDestSize && maxOutputSize < 1) return 0;         /* Impossible to store anything */
+    if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0;              /* Unsupported input size, too large (or negative) */
+
     ctx->end += inputSize;
+    if (limit == limitedDestSize) oend -= LASTLITERALS;                  /* Hack for support limitations LZ4 decompressor */
+    if (inputSize < LZ4_minLength) goto _last_literals;                  /* Input too small, no compression (all literals) */
 
     ip++;
 
@@ -353,10 +363,12 @@ static int LZ4HC_compress_hashChain (
 _Search2:
         if (ip+ml < mflimit)
             ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 0, matchlimit, ml, &ref2, &start2, maxNbAttempts);
-        else ml2 = ml;
+        else
+            ml2 = ml;
 
         if (ml2 == ml) { /* No better match */
-            if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0;
+            optr = op;
+            if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
             continue;
         }
 
@@ -377,11 +389,9 @@ _Search2:
         }
 
 _Search3:
-        /*
-        * Currently we have :
-        * ml2 > ml1, and
-        * ip1+3 <= ip2 (usually < ip1+ml1)
-        */
+        /* At this stage, we have :
+        *  ml2 > ml1, and
+        *  ip1+3 <= ip2 (usually < ip1+ml1) */
         if ((start2 - ip) < OPTIMAL_ML) {
             int correction;
             int new_ml = ml;
@@ -398,15 +408,18 @@ _Search3:
 
         if (start2 + ml2 < mflimit)
             ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3, maxNbAttempts);
-        else ml3 = ml2;
+        else
+            ml3 = ml2;
 
         if (ml3 == ml2) {  /* No better match : 2 sequences to encode */
             /* ip & ref are known; Now for ml */
             if (start2 < ip+ml)  ml = (int)(start2 - ip);
             /* Now, encode 2 sequences */
-            if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0;
+            optr = op;
+            if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
             ip = start2;
-            if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) return 0;
+            optr = op;
+            if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) goto _dest_overflow;
             continue;
         }
 
@@ -424,7 +437,8 @@ _Search3:
                     }
                 }
 
-                if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0;
+                optr = op;
+                if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
                 ip  = start3;
                 ref = ref3;
                 ml  = ml3;
@@ -460,7 +474,8 @@ _Search3:
                 ml = (int)(start2 - ip);
             }
         }
-        if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0;
+        optr = op;
+        if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
 
         ip = start2;
         ref = ref2;
@@ -473,65 +488,99 @@ _Search3:
         goto _Search3;
     }
 
+_last_literals:
     /* Encode Last Literals */
-    {   int lastRun = (int)(iend - anchor);
-        if ((limit) && (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize)) return 0;  /* Check output limit */
-        if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; }
-        else *op++ = (BYTE)(lastRun<<ML_BITS);
-        memcpy(op, anchor, iend - anchor);
-        op += iend-anchor;
+    {   size_t lastRunSize = (size_t)(iend - anchor);  /* literals */
+        size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255;
+        size_t const totalSize = 1 + litLength + lastRunSize;
+        if (limit == limitedDestSize) oend += LASTLITERALS;  /* restore correct value */
+        if (limit && (op + totalSize > oend)) {
+            if (limit == limitedOutput) return 0;  /* Check output limit */
+            /* adapt lastRunSize to fill 'dest' */
+            lastRunSize  = (size_t)(oend - op) - 1;
+            litLength = (lastRunSize + 255 - RUN_MASK) / 255;
+            lastRunSize -= litLength;
+        }
+        ip = anchor + lastRunSize;
+
+        if (lastRunSize >= RUN_MASK) {
+            size_t accumulator = lastRunSize - RUN_MASK;
+            *op++ = (RUN_MASK << ML_BITS);
+            for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255;
+            *op++ = (BYTE) accumulator;
+        } else {
+            *op++ = (BYTE)(lastRunSize << ML_BITS);
+        }
+        memcpy(op, anchor, lastRunSize);
+        op += lastRunSize;
     }
 
     /* End */
+    *srcSizePtr = (int) (((const char*)ip) - source);
     return (int) (((char*)op)-dest);
+
+_dest_overflow:
+    if (limit == limitedDestSize) {
+        op = optr;  /* restore correct out pointer */
+        goto _last_literals;
+    }
+    return 0;
 }
 
 static int LZ4HC_getSearchNum(int compressionLevel)
 {
     switch (compressionLevel) {
         default: return 0; /* unused */
-        case 11: return 128; 
-        case 12: return 1<<10; 
+        case 11: return 128;
+        case 12: return 1<<10;
     }
 }
 
 static int LZ4HC_compress_generic (
     LZ4HC_CCtx_internal* const ctx,
-    const char* const source,
-    char* const dest,
-    int const inputSize,
-    int const maxOutputSize,
-    int compressionLevel,
+    const char* const src,
+    char* const dst,
+    int* const srcSizePtr,
+    int const dstCapacity,
+    int cLevel,
     limitedOutput_directive limit
     )
 {
-    if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT;
-    if (compressionLevel > 9) {
-        switch (compressionLevel) {
-            case 10: return LZ4HC_compress_hashChain(ctx, source, dest, inputSize, maxOutputSize, 1 << (16-1), limit);
-            case 11: ctx->searchNum = LZ4HC_getSearchNum(compressionLevel); return LZ4HC_compress_optimal(ctx, source, dest, inputSize, maxOutputSize, limit, 128, 0);
+    if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT;   /* note : convention is different from lz4frame, maybe to reconsider */
+    if (cLevel > 9) {
+        if (limit == limitedDestSize) cLevel = 10;
+        switch (cLevel) {
+            case 10:
+                return LZ4HC_compress_hashChain(ctx, src, dst, srcSizePtr, dstCapacity, 1 << 12, limit);
+            case 11:
+                ctx->searchNum = LZ4HC_getSearchNum(cLevel);
+                return LZ4HC_compress_optimal(ctx, src, dst, *srcSizePtr, dstCapacity, limit, 128, 0);
             default:
-            case 12: ctx->searchNum = LZ4HC_getSearchNum(compressionLevel); return LZ4HC_compress_optimal(ctx, source, dest, inputSize, maxOutputSize, limit, LZ4_OPT_NUM, 1);
+                cLevel = 12;
+                /* fall-through */
+            case 12:
+                ctx->searchNum = LZ4HC_getSearchNum(cLevel);
+                return LZ4HC_compress_optimal(ctx, src, dst, *srcSizePtr, dstCapacity, limit, LZ4_OPT_NUM, 1);
         }
     }
-    return LZ4HC_compress_hashChain(ctx, source, dest, inputSize, maxOutputSize, 1 << (compressionLevel-1), limit);
+    return LZ4HC_compress_hashChain(ctx, src, dst, srcSizePtr, dstCapacity, 1 << (cLevel-1), limit);  /* levels 1-9 */
 }
 
 
 int LZ4_sizeofStateHC(void) { return sizeof(LZ4_streamHC_t); }
 
-int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel)
+int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
 {
-    LZ4HC_CCtx_internal* ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
+    LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
     if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0;   /* Error : state is not aligned for pointers (32 or 64 bits) */
     LZ4HC_init (ctx, (const BYTE*)src);
-    if (maxDstSize < LZ4_compressBound(srcSize))
-        return LZ4HC_compress_generic (ctx, src, dst, srcSize, maxDstSize, compressionLevel, limitedOutput);
+    if (dstCapacity < LZ4_compressBound(srcSize))
+        return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput);
     else
-        return LZ4HC_compress_generic (ctx, src, dst, srcSize, maxDstSize, compressionLevel, noLimit);
+        return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, noLimit);
 }
 
-int LZ4_compress_HC(const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel)
+int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
 {
 #if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
     LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)malloc(sizeof(LZ4_streamHC_t));
@@ -539,13 +588,23 @@ int LZ4_compress_HC(const char* src, char* dst, int srcSize, int maxDstSize, int
     LZ4_streamHC_t state;
     LZ4_streamHC_t* const statePtr = &state;
 #endif
-    int const cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, maxDstSize, compressionLevel);
+    int const cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, dstCapacity, compressionLevel);
 #if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
     free(statePtr);
 #endif
     return cSize;
 }
 
+/* LZ4_compress_HC_destSize() :
+ * currently, only compatible with Hash Chain implementation,
+ * hence limit compression level to LZ4HC_CLEVEL_OPT_MIN-1*/
+int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel)
+{
+    LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse;
+    LZ4HC_init(ctx, (const BYTE*) source);
+    return LZ4HC_compress_generic(ctx, source, dest, sourceSizePtr, targetDestSize, cLevel, limitedDestSize);
+}
+
 
 
 /**************************************
@@ -553,7 +612,11 @@ int LZ4_compress_HC(const char* src, char* dst, int srcSize, int maxDstSize, int
 **************************************/
 /* allocation */
 LZ4_streamHC_t* LZ4_createStreamHC(void) { return (LZ4_streamHC_t*)malloc(sizeof(LZ4_streamHC_t)); }
-int             LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) { free(LZ4_streamHCPtr); return 0; }
+int             LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) {
+    if (!LZ4_streamHCPtr) return 0;  /* support free on NULL */
+    free(LZ4_streamHCPtr);
+    return 0;
+}
 
 
 /* initialization */
@@ -561,13 +624,24 @@ void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
 {
     LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= sizeof(size_t) * LZ4_STREAMHCSIZE_SIZET);   /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */
     LZ4_streamHCPtr->internal_donotuse.base = NULL;
-    LZ4_streamHCPtr->internal_donotuse.compressionLevel = (unsigned)compressionLevel;
+    if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX;  /* cap compression level */
+    LZ4_streamHCPtr->internal_donotuse.compressionLevel = compressionLevel;
     LZ4_streamHCPtr->internal_donotuse.searchNum = LZ4HC_getSearchNum(compressionLevel);
 }
 
+void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
+{
+    int const currentCLevel = LZ4_streamHCPtr->internal_donotuse.compressionLevel;
+    int const minCLevel = currentCLevel < LZ4HC_CLEVEL_OPT_MIN ? 1 : LZ4HC_CLEVEL_OPT_MIN;
+    int const maxCLevel = currentCLevel < LZ4HC_CLEVEL_OPT_MIN ? LZ4HC_CLEVEL_OPT_MIN-1 : LZ4HC_CLEVEL_MAX;
+    compressionLevel = MIN(compressionLevel, minCLevel);
+    compressionLevel = MAX(compressionLevel, maxCLevel);
+    LZ4_streamHCPtr->internal_donotuse.compressionLevel = compressionLevel;
+}
+
 int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize)
 {
-    LZ4HC_CCtx_internal* ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+    LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
     if (dictSize > 64 KB) {
         dictionary += dictSize - 64 KB;
         dictSize = 64 KB;
@@ -601,12 +675,13 @@ static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBl
 }
 
 static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr,
-                                            const char* source, char* dest,
-                                            int inputSize, int maxOutputSize, limitedOutput_directive limit)
+                                            const char* src, char* dst,
+                                            int* srcSizePtr, int dstCapacity,
+                                            limitedOutput_directive limit)
 {
-    LZ4HC_CCtx_internal* ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+    LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
     /* auto-init if forgotten */
-    if (ctxPtr->base == NULL) LZ4HC_init (ctxPtr, (const BYTE*) source);
+    if (ctxPtr->base == NULL) LZ4HC_init (ctxPtr, (const BYTE*) src);
 
     /* Check overflow */
     if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 GB) {
@@ -616,31 +691,39 @@ static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr,
     }
 
     /* Check if blocks follow each other */
-    if ((const BYTE*)source != ctxPtr->end) LZ4HC_setExternalDict(ctxPtr, (const BYTE*)source);
+    if ((const BYTE*)src != ctxPtr->end) LZ4HC_setExternalDict(ctxPtr, (const BYTE*)src);
 
     /* Check overlapping input/dictionary space */
-    {   const BYTE* sourceEnd = (const BYTE*) source + inputSize;
+    {   const BYTE* sourceEnd = (const BYTE*) src + *srcSizePtr;
         const BYTE* const dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit;
         const BYTE* const dictEnd   = ctxPtr->dictBase + ctxPtr->dictLimit;
-        if ((sourceEnd > dictBegin) && ((const BYTE*)source < dictEnd)) {
+        if ((sourceEnd > dictBegin) && ((const BYTE*)src < dictEnd)) {
             if (sourceEnd > dictEnd) sourceEnd = dictEnd;
             ctxPtr->lowLimit = (U32)(sourceEnd - ctxPtr->dictBase);
             if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4) ctxPtr->lowLimit = ctxPtr->dictLimit;
         }
     }
 
-    return LZ4HC_compress_generic (ctxPtr, source, dest, inputSize, maxOutputSize, ctxPtr->compressionLevel, limit);
+    return LZ4HC_compress_generic (ctxPtr, src, dst, srcSizePtr, dstCapacity, ctxPtr->compressionLevel, limit);
 }
 
-int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize)
+int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int srcSize, int dstCapacity)
 {
-    if (maxOutputSize < LZ4_compressBound(inputSize))
-        return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, source, dest, inputSize, maxOutputSize, limitedOutput);
+    if (dstCapacity < LZ4_compressBound(srcSize))
+        return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, limitedOutput);
     else
-        return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, source, dest, inputSize, maxOutputSize, noLimit);
+        return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, src, dst, &srcSize, dstCapacity, noLimit);
+}
+
+int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int* srcSizePtr, int targetDestSize)
+{
+    LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+    if (ctxPtr->compressionLevel >= LZ4HC_CLEVEL_OPT_MIN) LZ4HC_init(ctxPtr, (const BYTE*)src);   /* not compatible with btopt implementation */
+    return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, limitedDestSize);
 }
 
 
+
 /* dictionary saving */
 
 int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictSize)
@@ -700,16 +783,20 @@ void* LZ4_createHC (char* inputBuffer)
     return hc4;
 }
 
-int LZ4_freeHC (void* LZ4HC_Data) { FREEMEM(LZ4HC_Data); return 0; }
+int LZ4_freeHC (void* LZ4HC_Data) {
+    if (!LZ4HC_Data) return 0;  /* support free on NULL */
+    FREEMEM(LZ4HC_Data);
+    return 0;
+}
 
-int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel)
+int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int cLevel)
 {
-    return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, source, dest, inputSize, 0, compressionLevel, noLimit);
+    return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, 0, cLevel, noLimit);
 }
 
-int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel)
+int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* src, char* dst, int srcSize, int dstCapacity, int cLevel)
 {
-    return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, source, dest, inputSize, maxOutputSize, compressionLevel, limitedOutput);
+    return LZ4HC_compress_generic (&((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse, src, dst, &srcSize, dstCapacity, cLevel, limitedOutput);
 }
 
 char* LZ4_slideInputBufferHC(void* LZ4HC_Data)
diff --git a/lib/lz4hc.h b/lib/lz4hc.h
index 1036fd0..66d5636 100644
--- a/lib/lz4hc.h
+++ b/lib/lz4hc.h
@@ -1,7 +1,7 @@
 /*
    LZ4 HC - High Compression Mode of LZ4
    Header File
-   Copyright (C) 2011-2016, Yann Collet.
+   Copyright (C) 2011-2017, Yann Collet.
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
@@ -58,8 +58,8 @@ extern "C" {
  * `dst` must be already allocated.
  * Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h")
  * Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h")
- * `compressionLevel` : Recommended values are between 4 and 9, although any value between 1 and LZ4HC_MAX_CLEVEL will work.
- *                      Values >LZ4HC_MAX_CLEVEL behave the same as LZ4HC_MAX_CLEVEL.
+ * `compressionLevel` : Recommended values are between 4 and 9, although any value between 1 and LZ4HC_CLEVEL_MAX will work.
+ *                      Values >LZ4HC_CLEVEL_MAX behave the same as LZ4HC_CLEVEL_MAX.
  * @return : the number of bytes written into 'dst'
  *           or 0 if compression fails.
  */
@@ -113,25 +113,23 @@ LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, in
 
   Then, use LZ4_compress_HC_continue() to compress each successive block.
   Previous memory blocks (including initial dictionary when present) must remain accessible and unmodified during compression.
-  'dst' buffer should be sized to handle worst case scenarios, using LZ4_compressBound(), to ensure operation success.
+  'dst' buffer should be sized to handle worst case scenarios (see LZ4_compressBound()), to ensure operation success.
+  Because in case of failure, the API does not guarantee context recovery, and context will have to be reset.
+  If `dst` buffer budget cannot be >= LZ4_compressBound(), consider using LZ4_compress_HC_continue_destSize() instead.
 
-  If, for any reason, previous data blocks can't be preserved unmodified in memory during next compression block,
-  you must save it to a safer memory space, using LZ4_saveDictHC().
+  If, for any reason, previous data block can't be preserved unmodified in memory for next compression block,
+  you can save it to a more stable memory space, using LZ4_saveDictHC().
   Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer'.
 */
 
 
-/*-******************************************
- * !!!!!   STATIC LINKING ONLY   !!!!!
- *******************************************/
-
  /*-*************************************
  * PRIVATE DEFINITIONS :
  * Do not use these definitions.
  * They are exposed to allow static allocation of `LZ4_streamHC_t`.
  * Using these definitions makes the code vulnerable to potential API break when upgrading LZ4
  **************************************/
-#define LZ4HC_DICTIONARY_LOGSIZE 17
+#define LZ4HC_DICTIONARY_LOGSIZE 17   /* because of btopt, hc would only need 16 */
 #define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE)
 #define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1)
 
@@ -147,14 +145,14 @@ typedef struct
 {
     uint32_t   hashTable[LZ4HC_HASHTABLESIZE];
     uint16_t   chainTable[LZ4HC_MAXD];
-    const uint8_t* end;        /* next block here to continue on current prefix */
-    const uint8_t* base;       /* All index relative to this position */
-    const uint8_t* dictBase;   /* alternate base for extDict */
-    uint8_t* inputBuffer;      /* deprecated */
-    uint32_t   dictLimit;        /* below that point, need extDict */
-    uint32_t   lowLimit;         /* below that point, no more dict */
-    uint32_t   nextToUpdate;     /* index from which to continue dictionary update */
-    uint32_t   searchNum;        /* only for optimal parser */
+    const uint8_t* end;         /* next block here to continue on current prefix */
+    const uint8_t* base;        /* All index relative to this position */
+    const uint8_t* dictBase;    /* alternate base for extDict */
+    uint8_t* inputBuffer;       /* deprecated */
+    uint32_t   dictLimit;       /* below that point, need extDict */
+    uint32_t   lowLimit;        /* below that point, no more dict */
+    uint32_t   nextToUpdate;    /* index from which to continue dictionary update */
+    uint32_t   searchNum;       /* only for optimal parser */
     uint32_t   compressionLevel;
 } LZ4HC_CCtx_internal;
 
@@ -163,7 +161,7 @@ typedef struct
 typedef struct
 {
     unsigned int   hashTable[LZ4HC_HASHTABLESIZE];
-    unsigned short   chainTable[LZ4HC_MAXD];
+    unsigned short chainTable[LZ4HC_MAXD];
     const unsigned char* end;        /* next block here to continue on current prefix */
     const unsigned char* base;       /* All index relative to this position */
     const unsigned char* dictBase;   /* alternate base for extDict */
@@ -172,7 +170,7 @@ typedef struct
     unsigned int   lowLimit;         /* below that point, no more dict */
     unsigned int   nextToUpdate;     /* index from which to continue dictionary update */
     unsigned int   searchNum;        /* only for optimal parser */
-    unsigned int   compressionLevel;
+    int            compressionLevel;
 } LZ4HC_CCtx_internal;
 
 #endif
@@ -200,25 +198,25 @@ union LZ4_streamHC_u {
 
 /* deprecated compression functions */
 /* these functions will trigger warning messages in future releases */
-LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC               (const char* source, char* dest, int inputSize);
-LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
-LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
-LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
-LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_withStateHC               (void* state, const char* source, char* dest, int inputSize);
-LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
-LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
-LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
-LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_continue               (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
-LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC               (const char* source, char* dest, int inputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_withStateHC               (void* state, const char* source, char* dest, int inputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_continue               (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
 
 /* Deprecated Streaming functions using older model; should no longer be used */
-LZ4_DEPRECATED("use LZ4_createStreamHC() instead") void* LZ4_createHC (char* inputBuffer);
-LZ4_DEPRECATED("use LZ4_saveDictHC() instead")     char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
-LZ4_DEPRECATED("use LZ4_freeStreamHC() instead")   int   LZ4_freeHC (void* LZ4HC_Data);
-LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
-LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
-LZ4_DEPRECATED("use LZ4_createStreamHC() instead") int   LZ4_sizeofStreamStateHC(void);
-LZ4_DEPRECATED("use LZ4_resetStreamHC() instead")  int   LZ4_resetStreamStateHC(void* state, char* inputBuffer);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_createStreamHC() instead") void* LZ4_createHC (char* inputBuffer);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_saveDictHC() instead")     char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_freeStreamHC() instead")   int   LZ4_freeHC (void* LZ4HC_Data);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_createStreamHC() instead") int   LZ4_sizeofStreamStateHC(void);
+LZ4LIB_API LZ4_DEPRECATED("use LZ4_resetStreamHC() instead")  int   LZ4_resetStreamStateHC(void* state, char* inputBuffer);
 
 
 #if defined (__cplusplus)
@@ -226,3 +224,55 @@ LZ4_DEPRECATED("use LZ4_resetStreamHC() instead")  int   LZ4_resetStreamStateHC(
 #endif
 
 #endif /* LZ4_HC_H_19834876238432 */
+
+/*-************************************************
+ * !!!!!     STATIC LINKING ONLY     !!!!!
+ * Following definitions are considered experimental.
+ * They should not be linked from DLL,
+ * as there is no guarantee of API stability yet.
+ * Prototypes will be promoted to "stable" status
+ * after successfull usage in real-life scenarios.
+ *************************************************/
+#ifdef LZ4_HC_STATIC_LINKING_ONLY   /* protection macro */
+#ifndef LZ4_HC_SLO_098092834
+#define LZ4_HC_SLO_098092834
+
+/*! LZ4_compress_HC_destSize() : v1.8.0 (experimental)
+ *  Will try to compress as much data from `src` as possible
+ *  that can fit into `targetDstSize` budget.
+ *  Result is provided in 2 parts :
+ * @return : the number of bytes written into 'dst'
+ *           or 0 if compression fails.
+ * `srcSizePtr` : value will be updated to indicate how much bytes were read from `src`
+ */
+int LZ4_compress_HC_destSize(void* LZ4HC_Data,
+                            const char* src, char* dst,
+                            int* srcSizePtr, int targetDstSize,
+                            int compressionLevel);
+
+/*! LZ4_compress_HC_continue_destSize() : v1.8.0 (experimental)
+ *  Similar as LZ4_compress_HC_continue(),
+ *  but will read a variable nb of bytes from `src`
+ *  to fit into `targetDstSize` budget.
+ *  Result is provided in 2 parts :
+ * @return : the number of bytes written into 'dst'
+ *           or 0 if compression fails.
+ * `srcSizePtr` : value will be updated to indicate how much bytes were read from `src`.
+ *  Important : due to limitations, this prototype only works well up to cLevel < LZ4HC_CLEVEL_OPT_MIN
+ *              beyond that level, compression performance will be much reduced due to internal incompatibilities
+ */
+int LZ4_compress_HC_continue_destSize(LZ4_streamHC_t* LZ4_streamHCPtr,
+                            const char* src, char* dst,
+                            int* srcSizePtr, int targetDstSize);
+
+/*! LZ4_setCompressionLevel() : v1.8.0 (experimental)
+ *  It's possible to change compression level after LZ4_resetStreamHC(), between 2 invocations of LZ4_compress_HC_continue*(),
+ *  but that requires to stay in the same mode (aka 1-10 or 11-12).
+ *  This function ensures this condition.
+ */
+void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
+
+
+
+#endif   /* LZ4_HC_SLO_098092834 */
+#endif   /* LZ4_HC_STATIC_LINKING_ONLY */
diff --git a/lib/lz4opt.h b/lib/lz4opt.h
index d1913fe..e9e54d8 100644
--- a/lib/lz4opt.h
+++ b/lib/lz4opt.h
@@ -1,6 +1,6 @@
 /*
     lz4opt.h - Optimal Mode of LZ4
-    Copyright (C) 2015-2016, Przemyslaw Skibinski <inikep@gmail.com>
+    Copyright (C) 2015-2017, Przemyslaw Skibinski <inikep@gmail.com>
     Note : this file is intended to be included within lz4hc.c
 
     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
@@ -36,14 +36,12 @@
 #define LZ4_OPT_NUM   (1<<12)
 
 
-typedef struct
-{
+typedef struct {
     int off;
     int len;
 } LZ4HC_match_t;
 
-typedef struct
-{
+typedef struct {
     int price;
     int off;
     int mlen;
@@ -51,11 +49,12 @@ typedef struct
 } LZ4HC_optimal_t;
 
 
-/* price in bits */
+/* price in bytes */
 FORCE_INLINE size_t LZ4HC_literalsPrice(size_t litlen)
 {
-    size_t price = 8*litlen;
-    if (litlen >= (size_t)RUN_MASK) price+=8*(1+(litlen-RUN_MASK)/255);
+    size_t price = litlen;
+    if (litlen >= (size_t)RUN_MASK)
+        price += 1 + (litlen-RUN_MASK)/255;
     return price;
 }
 
@@ -63,12 +62,12 @@ FORCE_INLINE size_t LZ4HC_literalsPrice(size_t litlen)
 /* requires mlen >= MINMATCH */
 FORCE_INLINE size_t LZ4HC_sequencePrice(size_t litlen, size_t mlen)
 {
-    size_t price = 16 + 8; /* 16-bit offset + token */
+    size_t price = 2 + 1; /* 16-bit offset + token */
 
     price += LZ4HC_literalsPrice(litlen);
 
-    mlen -= MINMATCH;
-    if (mlen >= (size_t)ML_MASK) price+=8*(1+(mlen-ML_MASK)/255);
+    if (mlen >= (size_t)(ML_MASK+MINMATCH))
+        price+= 1 + (mlen-(ML_MASK+MINMATCH))/255;
 
     return price;
 }
@@ -123,6 +122,8 @@ FORCE_INLINE int LZ4HC_BinTree_InsertAndGetAllMatches (
             matchLength = LZ4_count(ip, match, vLimit);
             if ((ip+matchLength == vLimit) && (vLimit < iHighLimit))
                 matchLength += LZ4_count(ip+matchLength, base+dictLimit, iHighLimit);
+            if (matchIndex+matchLength >= dictLimit)
+                match = base + matchIndex;   /* to prepare for next usage of match[matchLength] */
         }
 
         if (matchLength > best_mlen) {
@@ -141,6 +142,8 @@ FORCE_INLINE int LZ4HC_BinTree_InsertAndGetAllMatches (
         if (ip+matchLength >= iHighLimit)   /* equal : no way to know if inf or sup */
             break;   /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt the tree */
 
+        DEBUGLOG(6, "ip   :%016llX", (U64)ip);
+        DEBUGLOG(6, "match:%016llX", (U64)match);
         if (*(ip+matchLength) < *(match+matchLength)) {
             *ptr0 = delta0;
             ptr0 = &DELTANEXTMAXD(matchIndex*2);
@@ -192,13 +195,13 @@ FORCE_INLINE int LZ4HC_BinTree_GetAllMatches (
 }
 
 
-#define SET_PRICE(pos, mlen, offset, litlen, price)    \
+#define SET_PRICE(pos, ml, offset, ll, cost)           \
 {                                                      \
     while (last_pos < pos)  { opt[last_pos+1].price = 1<<30; last_pos++; } \
-    opt[pos].mlen = (int)mlen;                         \
+    opt[pos].mlen = (int)ml;                           \
     opt[pos].off = (int)offset;                        \
-    opt[pos].litlen = (int)litlen;                     \
-    opt[pos].price = (int)price;                       \
+    opt[pos].litlen = (int)ll;                         \
+    opt[pos].price = (int)cost;                        \
 }
 
 
@@ -209,15 +212,12 @@ static int LZ4HC_compress_optimal (
     int inputSize,
     int maxOutputSize,
     limitedOutput_directive limit,
-    const size_t sufficient_len,
+    size_t sufficient_len,
     const int fullUpdate
     )
 {
-    LZ4HC_optimal_t opt[LZ4_OPT_NUM + 1];
+    LZ4HC_optimal_t opt[LZ4_OPT_NUM + 1];   /* this uses a bit too much stack memory to my taste ... */
     LZ4HC_match_t matches[LZ4_OPT_NUM + 1];
-    const BYTE *inr = NULL;
-    size_t res, cur, cur2;
-    size_t i, llen, litlen, mlen, best_mlen, price, offset, best_off, match_num, last_pos;
 
     const BYTE* ip = (const BYTE*) source;
     const BYTE* anchor = ip;
@@ -228,18 +228,23 @@ static int LZ4HC_compress_optimal (
     BYTE* const oend = op + maxOutputSize;
 
     /* init */
+    DEBUGLOG(5, "LZ4HC_compress_optimal");
+    if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1;
     ctx->end += inputSize;
     ip++;
 
     /* Main Loop */
     while (ip < mflimit) {
-        memset(opt, 0, sizeof(LZ4HC_optimal_t));
-        last_pos = 0;
-        llen = ip - anchor;
+        size_t const llen = ip - anchor;
+        size_t last_pos = 0;
+        size_t match_num, cur, best_mlen, best_off;
+        memset(opt, 0, sizeof(LZ4HC_optimal_t));  /* memset only the first one */
+
         match_num = LZ4HC_BinTree_GetAllMatches(ctx, ip, matchlimit, MINMATCH-1, matches, fullUpdate);
         if (!match_num) { ip++; continue; }
 
         if ((size_t)matches[match_num-1].len > sufficient_len) {
+            /* good enough solution : immediate encoding */
             best_mlen = matches[match_num-1].len;
             best_off = matches[match_num-1].off;
             cur = 0;
@@ -248,45 +253,46 @@ static int LZ4HC_compress_optimal (
         }
 
         /* set prices using matches at position = 0 */
-        for (i = 0; i < match_num; i++) {
-           mlen = (i>0) ? (size_t)matches[i-1].len+1 : MINMATCH;
-           best_mlen = (matches[i].len < LZ4_OPT_NUM) ? matches[i].len : LZ4_OPT_NUM;
-           while (mlen <= best_mlen) {
-                litlen = 0;
-                price = LZ4HC_sequencePrice(llen + litlen, mlen) - LZ4HC_literalsPrice(llen);
-                SET_PRICE(mlen, mlen, matches[i].off, litlen, price);
-                mlen++;
-           }
-        }
+        {   size_t matchNb;
+            for (matchNb = 0; matchNb < match_num; matchNb++) {
+                size_t mlen = (matchNb>0) ? (size_t)matches[matchNb-1].len+1 : MINMATCH;
+                best_mlen = matches[matchNb].len;   /* necessarily < sufficient_len < LZ4_OPT_NUM */
+                for ( ; mlen <= best_mlen ; mlen++) {
+                    size_t const cost = LZ4HC_sequencePrice(llen, mlen) - LZ4HC_literalsPrice(llen);
+                    SET_PRICE(mlen, mlen, matches[matchNb].off, 0, cost);   /* updates last_pos and opt[pos] */
+        }   }   }
 
-        if (last_pos < MINMATCH) { ip++; continue; }
+        if (last_pos < MINMATCH) { ip++; continue; }  /* note : on clang at least, this test improves performance */
 
         /* check further positions */
         opt[0].mlen = opt[1].mlen = 1;
         for (cur = 1; cur <= last_pos; cur++) {
-            inr = ip + cur;
-
-            if (opt[cur-1].mlen == 1) {
-                litlen = opt[cur-1].litlen + 1;
-                if (cur != litlen) {
-                    price = opt[cur - litlen].price + LZ4HC_literalsPrice(litlen);
+            const BYTE* const curPtr = ip + cur;
+
+            /* establish baseline price if cur is literal */
+            {   size_t price, litlen;
+                if (opt[cur-1].mlen == 1) {
+                    /* no match at previous position */
+                    litlen = opt[cur-1].litlen + 1;
+                    if (cur > litlen) {
+                        price = opt[cur - litlen].price + LZ4HC_literalsPrice(litlen);
+                    } else {
+                        price = LZ4HC_literalsPrice(llen + litlen) - LZ4HC_literalsPrice(llen);
+                    }
                 } else {
-                    price = LZ4HC_literalsPrice(llen + litlen) - LZ4HC_literalsPrice(llen);
+                    litlen = 1;
+                    price = opt[cur - 1].price + LZ4HC_literalsPrice(1);
                 }
-            } else {
-                litlen = 1;
-                price = opt[cur - 1].price + LZ4HC_literalsPrice(litlen);
-            }
 
-            mlen = 1;
-            best_mlen = 0;
-            if (cur > last_pos || price < (size_t)opt[cur].price)
-                SET_PRICE(cur, mlen, best_mlen, litlen, price);
+                if (price < (size_t)opt[cur].price)
+                    SET_PRICE(cur, 1 /*mlen*/, 0 /*off*/, litlen, price);   /* note : increases last_pos */
+            }
 
-            if (cur == last_pos || inr >= mflimit) break;
+            if (cur == last_pos || curPtr >= mflimit) break;
 
-            match_num = LZ4HC_BinTree_GetAllMatches(ctx, inr, matchlimit, MINMATCH-1, matches, fullUpdate);
-            if (match_num > 0 && (size_t)matches[match_num-1].len > sufficient_len) {
+            match_num = LZ4HC_BinTree_GetAllMatches(ctx, curPtr, matchlimit, MINMATCH-1, matches, fullUpdate);
+            if ((match_num > 0) && (size_t)matches[match_num-1].len > sufficient_len) {
+                /* immediate encoding */
                 best_mlen = matches[match_num-1].len;
                 best_off = matches[match_num-1].off;
                 last_pos = cur + 1;
@@ -294,60 +300,57 @@ static int LZ4HC_compress_optimal (
             }
 
             /* set prices using matches at position = cur */
-            for (i = 0; i < match_num; i++) {
-                mlen = (i>0) ? (size_t)matches[i-1].len+1 : MINMATCH;
-                cur2 = cur;
-                best_mlen = (cur2 + matches[i].len < LZ4_OPT_NUM) ? (size_t)matches[i].len : LZ4_OPT_NUM - cur2;
-
-                while (mlen <= best_mlen) {
-                    if (opt[cur2].mlen == 1) {
-                        litlen = opt[cur2].litlen;
-
-                        if (cur2 != litlen)
-                            price = opt[cur2 - litlen].price + LZ4HC_sequencePrice(litlen, mlen);
-                        else
-                            price = LZ4HC_sequencePrice(llen + litlen, mlen) - LZ4HC_literalsPrice(llen);
-                    } else {
-                        litlen = 0;
-                        price = opt[cur2].price + LZ4HC_sequencePrice(litlen, mlen);
-                    }
-
-                    if (cur2 + mlen > last_pos || price < (size_t)opt[cur2 + mlen].price) { // || (((int)price == opt[cur2 + mlen].price) && (opt[cur2 + mlen-1].mlen == 1))) {
-                        SET_PRICE(cur2 + mlen, mlen, matches[i].off, litlen, price);
-                    }
-                    mlen++;
-                }
-            }
+            {   size_t matchNb;
+                for (matchNb = 0; matchNb < match_num; matchNb++) {
+                    size_t ml = (matchNb>0) ? (size_t)matches[matchNb-1].len+1 : MINMATCH;
+                    best_mlen = (cur + matches[matchNb].len < LZ4_OPT_NUM) ?
+                                (size_t)matches[matchNb].len : LZ4_OPT_NUM - cur;
+
+                    for ( ; ml <= best_mlen ; ml++) {
+                        size_t ll, price;
+                        if (opt[cur].mlen == 1) {
+                            ll = opt[cur].litlen;
+                            if (cur > ll)
+                                price = opt[cur - ll].price + LZ4HC_sequencePrice(ll, ml);
+                            else
+                                price = LZ4HC_sequencePrice(llen + ll, ml) - LZ4HC_literalsPrice(llen);
+                        } else {
+                            ll = 0;
+                            price = opt[cur].price + LZ4HC_sequencePrice(0, ml);
+                        }
+
+                        if (cur + ml > last_pos || price < (size_t)opt[cur + ml].price) {
+                            SET_PRICE(cur + ml, ml, matches[matchNb].off, ll, price);
+            }   }   }   }
         } /* for (cur = 1; cur <= last_pos; cur++) */
 
         best_mlen = opt[last_pos].mlen;
         best_off = opt[last_pos].off;
         cur = last_pos - best_mlen;
 
-encode: /* cur, last_pos, best_mlen, best_off have to be set */
+encode: /* cur, last_pos, best_mlen, best_off must be set */
         opt[0].mlen = 1;
-        while (1) {
-            mlen = opt[cur].mlen;
-            offset = opt[cur].off;
+        while (1) {  /* from end to beginning */
+            size_t const ml = opt[cur].mlen;
+            int const offset = opt[cur].off;
             opt[cur].mlen = (int)best_mlen;
             opt[cur].off = (int)best_off;
-            best_mlen = mlen;
+            best_mlen = ml;
             best_off = offset;
-            if (mlen > cur) break;
-            cur -= mlen;
+            if (ml > cur) break;   /* can this happen ? */
+            cur -= ml;
         }
 
+        /* encode all recorded sequences */
         cur = 0;
         while (cur < last_pos) {
-            mlen = opt[cur].mlen;
-            if (mlen == 1) { ip++; cur++; continue; }
-            offset = opt[cur].off;
-            cur += mlen;
-
-            res = LZ4HC_encodeSequence(&ip, &op, &anchor, (int)mlen, ip - offset, limit, oend);
-            if (res) return 0;
+            int const ml = opt[cur].mlen;
+            int const offset = opt[cur].off;
+            if (ml == 1) { ip++; cur++; continue; }
+            cur += ml;
+            if ( LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ip - offset, limit, oend) ) return 0;
         }
-    }
+    }  /* while (ip < mflimit) */
 
     /* Encode Last Literals */
     {   int lastRun = (int)(iend - anchor);
diff --git a/lib/xxhash.c b/lib/xxhash.c
index e9ff2d4..a532358 100644
--- a/lib/xxhash.c
+++ b/lib/xxhash.c
@@ -113,19 +113,24 @@ static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcp
 ***************************************/
 #ifdef _MSC_VER    /* Visual Studio */
 #  pragma warning(disable : 4127)      /* disable: C4127: conditional expression is constant */
-#  define FORCE_INLINE static __forceinline
-#else
-#  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
-#    ifdef __GNUC__
-#      define FORCE_INLINE static inline __attribute__((always_inline))
-#    else
-#      define FORCE_INLINE static inline
-#    endif
-#  else
-#    define FORCE_INLINE static
-#  endif /* __STDC_VERSION__ */
 #endif
 
+#ifndef FORCE_INLINE
+#  ifdef _MSC_VER    /* Visual Studio */
+#    define FORCE_INLINE static __forceinline
+#  else
+#    if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
+#      ifdef __GNUC__
+#        define FORCE_INLINE static inline __attribute__((always_inline))
+#      else
+#        define FORCE_INLINE static inline
+#      endif
+#    else
+#      define FORCE_INLINE static
+#    endif /* __STDC_VERSION__ */
+#  endif  /* _MSC_VER */
+#endif /* FORCE_INLINE */
+
 
 /* *************************************
 *  Basic Types