Merge remote-tracking branch 'refs/remotes/lz4/dev' into dev

1 files changed, 125 insertions, 109 deletions

diff --git a/lib/lz4hc.h b/lib/lz4hc.h
index 563ad98..7adc8fa 100644
--- a/lib/lz4hc.h
+++ b/lib/lz4hc.h
@@ -1,7 +1,7 @@
 /*
    LZ4 HC - High Compression Mode of LZ4
    Header File
-   Copyright (C) 2011-2015, Yann Collet.
+   Copyright (C) 2011-2016, 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
@@ -34,121 +34,85 @@
 #ifndef LZ4_HC_H_19834876238432
 #define LZ4_HC_H_19834876238432
 
-
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
-/*-***************************
-*  Includes
-*****************************/
-#include <stddef.h>   /* size_t */
-
-/*-***************************************************************
-*  Export parameters
-*****************************************************************/
-/*!
-*  LZ4_DLL_EXPORT :
-*  Enable exporting of functions when building a Windows DLL
-*/
-#if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
-#  define LZ4HCLIB_API __declspec(dllexport)
-#elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1)
-#  define LZ4HCLIB_API __declspec(dllimport)
-#else
-#  define LZ4HCLIB_API
-#endif
+/* --- Dependency --- */
+/* note : lz4hc is not an independent module, it requires lz4.h/lz4.c for proper compilation */
+#include "lz4.h"   /* stddef, LZ4LIB_API, LZ4_DEPRECATED */
 
 
+/* --- Useful constants --- */
 #define LZ4HC_MIN_CLEVEL        3
 #define LZ4HC_DEFAULT_CLEVEL    9
 #define LZ4HC_MAX_CLEVEL        16
 
+
 /*-************************************
-*  Block Compression
-**************************************/
-/*!
-LZ4_compress_HC() :
-    Destination buffer `dst` must be already allocated.
-    Compression success is guaranteed if `dst` buffer is sized to handle worst circumstances (data not compressible)
-    Worst size evaluation is provided by function LZ4_compressBound() (see "lz4.h")
-      `srcSize`  : Max supported value is LZ4_MAX_INPUT_SIZE (see "lz4.h")
-      `compressionLevel` : Recommended values are between 4 and 9, although any value between 0 and LZ4HC_MAX_CLEVEL will work.
-                           0 means "use default value" (see lz4hc.c).
-                           Values >LZ4HC_MAX_CLEVEL behave the same as 16.
-      @return : the number of bytes written into buffer 'dst'
-             or 0 if compression fails.
-*/
-LZ4HCLIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
+ *  Block Compression
+ **************************************/
+/*! LZ4_compress_HC() :
+ * Compress data from `src` into `dst`, using the more powerful but slower "HC" algorithm.
+ * `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 16.
+ * @return : the number of bytes written into 'dst'
+ *           or 0 if compression fails.
+ */
+LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel);
 
 
 /* Note :
-   Decompression functions are provided within "lz4.h" (BSD license)
-*/
+ *   Decompression functions are provided within "lz4.h" (BSD license)
+ */
 
 
-/*!
-LZ4_compress_HC_extStateHC() :
-   Use this function if you prefer to manually allocate memory for compression tables.
-   To know how much memory must be allocated for the compression tables, use :
-      int LZ4_sizeofStateHC();
-
-   Allocated memory must be aligned on 8-bytes boundaries (which a normal malloc() will do properly).
-
-   The allocated memory can then be provided to the compression functions using 'void* state' parameter.
-   LZ4_compress_HC_extStateHC() is equivalent to previously described function.
-   It just uses externally allocated memory for stateHC.
-*/
-LZ4HCLIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
-LZ4HCLIB_API int LZ4_sizeofStateHC(void);
+/*! LZ4_compress_HC_extStateHC() :
+ * Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`.
+ * `state` size is provided by LZ4_sizeofStateHC().
+ * Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() will do properly).
+ */
+LZ4LIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
+LZ4LIB_API int LZ4_sizeofStateHC(void);
 
 
 /*-************************************
-*  Streaming Compression
-**************************************/
-#define LZ4_STREAMHCSIZE        262192
-#define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t))
-typedef struct { size_t table[LZ4_STREAMHCSIZE_SIZET]; } LZ4_streamHC_t;
-/*
-  LZ4_streamHC_t
-  This structure allows static allocation of LZ4 HC streaming state.
-  State must then be initialized using LZ4_resetStreamHC() before first use.
-
-  Static allocation should only be used in combination with static linking.
-  If you want to use LZ4 as a DLL, please use construction functions below, which are future-proof.
-*/
-
+ *  Streaming Compression
+ *  Bufferless synchronous API
+ **************************************/
+ typedef struct LZ4_streamHC_s LZ4_streamHC_t;   /* incomplete type (defined later) */
 
 /*! LZ4_createStreamHC() and LZ4_freeStreamHC() :
-  These functions create and release memory for LZ4 HC streaming state.
-  Newly created states are already initialized.
-  Existing state space can be re-used anytime using LZ4_resetStreamHC().
-  If you use LZ4 as a DLL, use these functions instead of static structure allocation,
-  to avoid size mismatch between different versions.
-*/
-LZ4HCLIB_API LZ4_streamHC_t* LZ4_createStreamHC(void);
-LZ4HCLIB_API int             LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr);
+ * These functions create and release memory for LZ4 HC streaming state.
+ * Newly created states are automatically initialized.
+ * Existing states can be re-used several times, using LZ4_resetStreamHC().
+ * These methods are API and ABI stable, they can be used in combination with a DLL.
+ */
+LZ4LIB_API LZ4_streamHC_t* LZ4_createStreamHC(void);
+LZ4LIB_API int             LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr);
 
-LZ4HCLIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel);
-LZ4HCLIB_API int  LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize);
+LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel);
+LZ4LIB_API int  LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize);
 
-LZ4HCLIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr, const char* src, char* dst, int srcSize, int maxDstSize);
+LZ4LIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr, const char* src, char* dst, int srcSize, int maxDstSize);
 
-LZ4HCLIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, int maxDictSize);
+LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, int maxDictSize);
 
 /*
   These functions compress data in successive blocks of any size, using previous blocks as dictionary.
   One key assumption is that previous blocks (up to 64 KB) remain read-accessible while compressing next blocks.
   There is an exception for ring buffers, which can be smaller than 64 KB.
-  Such case is automatically detected and correctly handled by LZ4_compress_HC_continue().
+  Ring buffers scenario is automatically detected and handled by LZ4_compress_HC_continue().
 
   Before starting compression, state must be properly initialized, using LZ4_resetStreamHC().
   A first "fictional block" can then be designated as initial dictionary, using LZ4_loadDictHC() (Optional).
 
   Then, use LZ4_compress_HC_continue() to compress each successive block.
-  It works like LZ4_compress_HC(), but use previous memory blocks as dictionary to improve compression.
   Previous memory blocks (including initial dictionary when present) must remain accessible and unmodified during compression.
-  As a reminder, size 'dst' buffer to handle worst cases, using LZ4_compressBound(), to ensure success of compression operation.
+  'dst' buffer should be sized to handle worst case scenarios, using LZ4_compressBound(), to ensure operation success.
 
   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().
@@ -156,50 +120,102 @@ LZ4HCLIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* 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 16
+#define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE)
+#define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1)
+
+#define LZ4HC_HASH_LOG (LZ4HC_DICTIONARY_LOGSIZE-1)
+#define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG)
+#define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1)
+
+
+#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
+#include <stdint.h>
+
+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   compressionLevel;
+} LZ4HC_CCtx_internal;
+
+#else
+
+typedef struct
+{
+    unsigned int   hashTable[LZ4HC_HASHTABLESIZE];
+    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 */
+    unsigned char* inputBuffer;      /* deprecated */
+    unsigned int   dictLimit;        /* below that point, need extDict */
+    unsigned int   lowLimit;         /* below that point, no more dict */
+    unsigned int   nextToUpdate;     /* index from which to continue dictionary update */
+    unsigned int   compressionLevel;
+} LZ4HC_CCtx_internal;
+
+#endif
+
+#define LZ4_STREAMHCSIZE        262192
+#define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t))
+struct LZ4_streamHC_s {
+  union {
+    size_t table[LZ4_STREAMHCSIZE_SIZET];
+    LZ4HC_CCtx_internal internal_donotuse;
+  };
+};   /* previously typedef'd to LZ4_streamHC_t */
+/*
+  LZ4_streamHC_t :
+  This structure allows static allocation of LZ4 HC streaming state.
+  State must be initialized using LZ4_resetStreamHC() before first use.
+
+  Static allocation shall only be used in combination with static linking.
+  When invoking LZ4 from a DLL, use create/free functions instead, which are API and ABI stable.
+*/
+
 
 /*-************************************
 *  Deprecated Functions
 **************************************/
-/* Deprecate Warnings */
-/* Should these warnings messages be a problem,
-   it is generally possible to disable them,
-   with -Wno-deprecated-declarations for gcc
-   or _CRT_SECURE_NO_WARNINGS in Visual for example.
-   You can also define LZ4_DEPRECATE_WARNING_DEFBLOCK. */
-#ifndef LZ4_DEPRECATE_WARNING_DEFBLOCK
-#  define LZ4_DEPRECATE_WARNING_DEFBLOCK
-#  define LZ4_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
-#  if (LZ4_GCC_VERSION >= 405) || defined(__clang__)
-#    define LZ4_DEPRECATED(message) __attribute__((deprecated(message)))
-#  elif (LZ4_GCC_VERSION >= 301)
-#    define LZ4_DEPRECATED(message) __attribute__((deprecated))
-#  elif defined(_MSC_VER)
-#    define LZ4_DEPRECATED(message) __declspec(deprecated(message))
-#  else
-#    pragma message("WARNING: You need to implement LZ4_DEPRECATED for this compiler")
-#    define LZ4_DEPRECATED(message)
-#  endif
-#endif /* LZ4_DEPRECATE_WARNING_DEFBLOCK */
+/* see lz4.h LZ4_DISABLE_DEPRECATE_WARNINGS to turn off deprecation warnings */
 
 /* deprecated compression functions */
 /* these functions will trigger warning messages in future releases */
-LZ4HCLIB_API int LZ4_compressHC                (const char* source, char* dest, int inputSize);
-LZ4HCLIB_API int LZ4_compressHC_limitedOutput  (const char* source, char* dest, int inputSize, int maxOutputSize);
+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);
-LZ4HCLIB_API int LZ4_compressHC_withStateHC               (void* state, const char* source, char* dest, int inputSize);
-LZ4HCLIB_API 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_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);
-LZ4HCLIB_API int LZ4_compressHC_continue               (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
-LZ4HCLIB_API int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
+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);
 
 /* 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_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);