created LZ4_initStreamHC()

- promoted LZ4_resetStreamHC_fast() to stable
- moved LZ4_resetStreamHC() to deprecated (but do not generate a warning yet)
- Updated doc, to highlight difference between init and reset
- switched all invocations of LZ4_resetStreamHC() onto LZ4_initStreamHC()
- misc: ensure `make all` also builds /tests

3 files changed, 190 insertions, 143 deletions

diff --git a/lib/lz4frame.c b/lib/lz4frame.c
index 2164470..f076204 100644
--- a/lib/lz4frame.c
+++ b/lib/lz4frame.c
@@ -1,41 +1,44 @@
 /*
-LZ4 auto-framing library
-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
-modification, are permitted provided that the following conditions are
-met:
-
-* Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-* Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-You can contact the author at :
-- LZ4 homepage : http://www.lz4.org
-- LZ4 source repository : https://github.com/lz4/lz4
-*/
+ * LZ4 auto-framing library
+ * 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
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following disclaimer
+ *   in the documentation and/or other materials provided with the
+ *   distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * You can contact the author at :
+ * - LZ4 homepage : http://www.lz4.org
+ * - LZ4 source repository : https://github.com/lz4/lz4
+ */
 
 /* LZ4F is a stand-alone API to create LZ4-compressed Frames
-*  in full conformance with specification v1.6.1 .
-*  This library rely upon memory management capabilities.
-* */
+ * in full conformance with specification v1.6.1 .
+ * This library rely upon memory management capabilities (malloc, free)
+ * provided either by <stdlib.h>,
+ * or redirected towards another library of user's choice
+ * (see Memory Routines below).
+ */
 
 
 /*-************************************
@@ -62,20 +65,27 @@ You can contact the author at :
 /*-************************************
 *  Memory routines
 **************************************/
+/*
+ * User may redirect invocations of
+ * malloc(), calloc() and free()
+ * towards another library or solution of their choice
+ * by modifying below section.
+ */
 #include <stdlib.h>   /* malloc, calloc, free */
 #define ALLOC(s)       malloc(s)
-#ifndef LZ4_SRC_INCLUDED
-#define ALLOC_AND_ZERO(s)  calloc(1,(s))
+#ifndef LZ4_SRC_INCLUDED   /* avoid redefinition when sources are coalesced */
+#  define ALLOC_AND_ZERO(s)  calloc(1,(s))
 #endif
 #define FREEMEM(p)     free(p)
+
 #include <string.h>   /* memset, memcpy, memmove */
-#ifndef LZ4_SRC_INCLUDED
-#define MEM_INIT       memset
+#ifndef LZ4_SRC_INCLUDED  /* avoid redefinition when sources are coalesced */
+#  define MEM_INIT       memset
 #endif
 
 
 /*-************************************
-*  Includes
+*  Library declarations
 **************************************/
 #define LZ4F_STATIC_LINKING_ONLY
 #include "lz4frame.h"
@@ -606,11 +616,12 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
         if (cctxPtr->lz4CtxAlloc < ctxTypeID) {
             FREEMEM(cctxPtr->lz4CtxPtr);
             if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
-                cctxPtr->lz4CtxPtr = (void*)LZ4_createStream();
+                cctxPtr->lz4CtxPtr = LZ4_createStream();
             } else {
-                cctxPtr->lz4CtxPtr = (void*)LZ4_createStreamHC();
+                cctxPtr->lz4CtxPtr = LZ4_createStreamHC();
             }
-            if (cctxPtr->lz4CtxPtr == NULL) return err0r(LZ4F_ERROR_allocation_failed);
+            if (cctxPtr->lz4CtxPtr == NULL)
+                return err0r(LZ4F_ERROR_allocation_failed);
             cctxPtr->lz4CtxAlloc = ctxTypeID;
             cctxPtr->lz4CtxState = ctxTypeID;
         } else if (cctxPtr->lz4CtxState != ctxTypeID) {
@@ -619,7 +630,7 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
             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);
+                LZ4_initStreamHC((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
             }
             cctxPtr->lz4CtxState = ctxTypeID;
         }
@@ -1268,9 +1279,10 @@ static void LZ4F_updateDict(LZ4F_dctx* dctx,
         return;
     }
 
-    if (dstPtr - dstBufferStart + dstSize >= 64 KB) {  /* history in dstBuffer becomes large enough to become dictionary */
+    assert(dstPtr >= dstBufferStart);
+    if ((size_t)(dstPtr - dstBufferStart) + dstSize >= 64 KB) {  /* history in dstBuffer becomes large enough to become dictionary */
         dctx->dict = (const BYTE*)dstBufferStart;
-        dctx->dictSize = dstPtr - dstBufferStart + dstSize;
+        dctx->dictSize = (size_t)(dstPtr - dstBufferStart) + dstSize;
         return;
     }
 
@@ -1286,7 +1298,7 @@ static void LZ4F_updateDict(LZ4F_dctx* dctx,
     }
 
     if (withinTmp) { /* copy relevant dict portion in front of tmpOut within tmpOutBuffer */
-        size_t const preserveSize = dctx->tmpOut - dctx->tmpOutBuffer;
+        size_t const preserveSize = (size_t)(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;
@@ -1371,7 +1383,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
 
         case dstage_getFrameHeader:
             if ((size_t)(srcEnd-srcPtr) >= maxFHSize) {  /* enough to decode - shortcut */
-                size_t const hSize = LZ4F_decodeHeader(dctx, srcPtr, srcEnd-srcPtr);  /* will update dStage appropriately */
+                size_t const hSize = LZ4F_decodeHeader(dctx, srcPtr, (size_t)(srcEnd-srcPtr));  /* will update dStage appropriately */
                 if (LZ4F_isError(hSize)) return hSize;
                 srcPtr += hSize;
                 break;
@@ -1593,13 +1605,13 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
                         dict, (int)dictSize);
                 if (decodedSize < 0) return err0r(LZ4F_ERROR_GENERIC);   /* decompression failed */
                 if (dctx->frameInfo.contentChecksumFlag)
-                    XXH32_update(&(dctx->xxh), dstPtr, decodedSize);
+                    XXH32_update(&(dctx->xxh), dstPtr, (size_t)decodedSize);
                 if (dctx->frameInfo.contentSize)
-                    dctx->frameRemainingSize -= decodedSize;
+                    dctx->frameRemainingSize -= (size_t)decodedSize;
 
                 /* dictionary management */
                 if (dctx->frameInfo.blockMode==LZ4F_blockLinked)
-                    LZ4F_updateDict(dctx, dstPtr, decodedSize, dstStart, 0);
+                    LZ4F_updateDict(dctx, dstPtr, (size_t)decodedSize, dstStart, 0);
 
                 dstPtr += decodedSize;
                 dctx->dStage = dstage_getBlockHeader;
@@ -1636,10 +1648,10 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
                 if (decodedSize < 0)  /* decompression failed */
                     return err0r(LZ4F_ERROR_decompressionFailed);
                 if (dctx->frameInfo.contentChecksumFlag)
-                    XXH32_update(&(dctx->xxh), dctx->tmpOut, decodedSize);
+                    XXH32_update(&(dctx->xxh), dctx->tmpOut, (size_t)decodedSize);
                 if (dctx->frameInfo.contentSize)
-                    dctx->frameRemainingSize -= decodedSize;
-                dctx->tmpOutSize = decodedSize;
+                    dctx->frameRemainingSize -= (size_t)decodedSize;
+                dctx->tmpOutSize = (size_t)decodedSize;
                 dctx->tmpOutStart = 0;
                 dctx->dStage = dstage_flushOut;
             }
@@ -1767,7 +1779,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
       && ((unsigned)(dctx->dStage)-2 < (unsigned)(dstage_getSuffix)-2) )  /* valid stages : [init ... getSuffix[ */
     {
         if (dctx->dStage == dstage_flushOut) {
-            size_t const preserveSize = dctx->tmpOut - dctx->tmpOutBuffer;
+            size_t const preserveSize = (size_t)(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;
@@ -1791,8 +1803,8 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
         }
     }
 
-    *srcSizePtr = (srcPtr - srcStart);
-    *dstSizePtr = (dstPtr - dstStart);
+    *srcSizePtr = (size_t)(srcPtr - srcStart);
+    *dstSizePtr = (size_t)(dstPtr - dstStart);
     return nextSrcSizeHint;
 }
 
diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index 129bf0c..644b8eb 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -105,7 +105,7 @@ static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4)
 
 static void LZ4HC_init (LZ4HC_CCtx_internal* hc4, const BYTE* start)
 {
-    uptrval startingOffset = hc4->end - hc4->base;
+    uptrval startingOffset = (uptrval)(hc4->end - hc4->base);
     if (startingOffset > 1 GB) {
         LZ4HC_clearTables(hc4);
         startingOffset = 0;
@@ -266,7 +266,7 @@ LZ4HC_InsertAndGetWiderMatch (
             if (LZ4_read16(iLowLimit + longest - 1) == LZ4_read16(matchPtr - lookBackLength + longest - 1)) {
                 if (LZ4_read32(matchPtr) == pattern) {
                     int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr) : 0;
-                    matchLength = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
+                    matchLength = MINMATCH + (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
                     matchLength -= back;
                     if (matchLength > longest) {
                         longest = matchLength;
@@ -280,7 +280,7 @@ LZ4HC_InsertAndGetWiderMatch (
                 int back = 0;
                 const BYTE* vLimit = ip + (dictLimit - matchIndex);
                 if (vLimit > iHighLimit) vLimit = iHighLimit;
-                matchLength = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
+                matchLength = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
                 if ((ip+matchLength == vLimit) && (vLimit < iHighLimit))
                     matchLength += LZ4_count(ip+matchLength, lowPrefixPtr, iHighLimit);
                 back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0;
@@ -293,11 +293,11 @@ LZ4HC_InsertAndGetWiderMatch (
 
         if (chainSwap && matchLength==longest) {    /* better match => select a better chain */
             assert(lookBackLength==0);   /* search forward only */
-            if (matchIndex + longest <= ipIndex) {
+            if (matchIndex + (U32)longest <= ipIndex) {
                 U32 distanceToNextMatch = 1;
                 int pos;
                 for (pos = 0; pos <= longest - MINMATCH; pos++) {
-                    U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + pos);
+                    U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + (U32)pos);
                     if (candidateDist > distanceToNextMatch) {
                         distanceToNextMatch = candidateDist;
                         matchChainPos = pos;
@@ -353,12 +353,14 @@ LZ4HC_InsertAndGetWiderMatch (
         }   }   /* PA optimization */
 
         /* follow current chain */
-        matchIndex -= DELTANEXTU16(chainTable, matchIndex+matchChainPos);
+        matchIndex -= DELTANEXTU16(chainTable, matchIndex + matchChainPos);
 
     }  /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */
 
-    if (dict == usingDictCtxHc && nbAttempts && ipIndex - lowestMatchIndex < MAX_DISTANCE) {
-        size_t const dictEndOffset = dictCtx->end - dictCtx->base;
+    if ( dict == usingDictCtxHc
+      && nbAttempts
+      && ipIndex - lowestMatchIndex < MAX_DISTANCE) {
+        size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->base);
         U32 dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)];
         assert(dictEndOffset <= 1 GB);
         matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset;
@@ -370,22 +372,19 @@ LZ4HC_InsertAndGetWiderMatch (
                 int back = 0;
                 const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex);
                 if (vLimit > iHighLimit) vLimit = iHighLimit;
-                mlt = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
+                mlt = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
                 back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->base + dictCtx->dictLimit) : 0;
                 mlt -= back;
                 if (mlt > longest) {
                     longest = mlt;
                     *matchpos = base + matchIndex + back;
                     *startpos = ip + back;
-                }
-            }
+            }   }
 
             {   U32 const nextOffset = DELTANEXTU16(dictCtx->chainTable, dictMatchIndex);
                 dictMatchIndex -= nextOffset;
                 matchIndex -= nextOffset;
-            }
-        }
-    }
+    }   }   }
 
     return longest;
 }
@@ -518,7 +517,7 @@ LZ4_FORCE_INLINE int LZ4HC_compress_hashChain (
 
     /* Main Loop */
     while (ip <= mflimit) {
-        ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict);
+        ml = LZ4HC_InsertAndFindBestMatch(ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict);
         if (ml<MINMATCH) { ip++; continue; }
 
         /* saved, in case we would skip too much */
@@ -768,29 +767,31 @@ LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal (
 
 static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock);
 
-static int LZ4HC_compress_generic_noDictCtx (
-    LZ4HC_CCtx_internal* const ctx,
-    const char* const src,
-    char* const dst,
-    int* const srcSizePtr,
-    int const dstCapacity,
-    int cLevel,
-    limitedOutput_directive limit
-    )
+static int
+LZ4HC_compress_generic_noDictCtx (
+        LZ4HC_CCtx_internal* const ctx,
+        const char* const src,
+        char* const dst,
+        int* const srcSizePtr,
+        int const dstCapacity,
+        int cLevel,
+        limitedOutput_directive limit
+        )
 {
     assert(ctx->dictCtx == NULL);
     return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, noDictCtx);
 }
 
-static int LZ4HC_compress_generic_dictCtx (
-    LZ4HC_CCtx_internal* const ctx,
-    const char* const src,
-    char* const dst,
-    int* const srcSizePtr,
-    int const dstCapacity,
-    int cLevel,
-    limitedOutput_directive limit
-    )
+static int
+LZ4HC_compress_generic_dictCtx (
+        LZ4HC_CCtx_internal* const ctx,
+        const char* const src,
+        char* const dst,
+        int* const srcSizePtr,
+        int const dstCapacity,
+        int cLevel,
+        limitedOutput_directive limit
+        )
 {
     const size_t position = ctx->end - ctx->base - ctx->lowLimit;
     assert(ctx->dictCtx != NULL);
@@ -807,15 +808,16 @@ static int LZ4HC_compress_generic_dictCtx (
     }
 }
 
-static int LZ4HC_compress_generic (
-    LZ4HC_CCtx_internal* const ctx,
-    const char* const src,
-    char* const dst,
-    int* const srcSizePtr,
-    int const dstCapacity,
-    int cLevel,
-    limitedOutput_directive limit
-    )
+static int
+LZ4HC_compress_generic (
+        LZ4HC_CCtx_internal* const ctx,
+        const char* const src,
+        char* const dst,
+        int* const srcSizePtr,
+        int const dstCapacity,
+        int cLevel,
+        limitedOutput_directive limit
+        )
 {
     if (ctx->dictCtx == NULL) {
         return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
@@ -842,7 +844,7 @@ int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* ds
 int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
 {
     if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0;   /* Error : state is not aligned for pointers (32 or 64 bits) */
-    LZ4_resetStreamHC ((LZ4_streamHC_t*)state, compressionLevel);
+    LZ4_initStreamHC (state, compressionLevel);   /* full initialization, as there is no guarantee on state's content (could be freshly malloc'ed) */
     return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel);
 }
 
@@ -861,12 +863,10 @@ int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, in
     return cSize;
 }
 
-/* LZ4_compress_HC_destSize() :
- * only compatible with regular HC parser */
 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;
-    LZ4_resetStreamHC((LZ4_streamHC_t*)LZ4HC_Data, cLevel);
+    LZ4_initStreamHC(LZ4HC_Data, cLevel);   /* full initialization, as there is no guarantee on state's content (could be freshly malloc'ed) */
     LZ4HC_init(ctx, (const BYTE*) source);
     return LZ4HC_compress_generic(ctx, source, dest, sourceSizePtr, targetDestSize, cLevel, limitedDestSize);
 }
@@ -877,14 +877,16 @@ int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, i
 *  Streaming Functions
 **************************************/
 /* allocation */
-LZ4_streamHC_t* LZ4_createStreamHC(void) {
+LZ4_streamHC_t* LZ4_createStreamHC(void)
+{
     LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
     if (LZ4_streamHCPtr==NULL) return NULL;
-    LZ4_resetStreamHC(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);
+    LZ4_initStreamHC(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);  /* full initialization, malloc'ed buffer can be full of garbage */
     return LZ4_streamHCPtr;
 }
 
-int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) {
+int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr)
+{
     DEBUGLOG(4, "LZ4_freeStreamHC(%p)", LZ4_streamHCPtr);
     if (!LZ4_streamHCPtr) return 0;  /* support free on NULL */
     free(LZ4_streamHCPtr);
@@ -893,9 +895,10 @@ int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) {
 
 
 /* initialization */
-void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
+void LZ4_initStreamHC (void* state, 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_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)state;
+    LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= LZ4_STREAMHCSIZE);   /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */
     DEBUGLOG(4, "LZ4_resetStreamHC(%p, %d)", LZ4_streamHCPtr, compressionLevel);
     LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1;
     LZ4_streamHCPtr->internal_donotuse.base = NULL;
@@ -905,11 +908,17 @@ void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
     LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
 }
 
+/* just a stub */
+void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
+{
+    return LZ4_initStreamHC(LZ4_streamHCPtr, compressionLevel);
+}
+
 void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
 {
     DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel);
     if (LZ4_streamHCPtr->internal_donotuse.dirty) {
-        LZ4_resetStreamHC(LZ4_streamHCPtr, compressionLevel);
+        LZ4_initStreamHC(LZ4_streamHCPtr, compressionLevel);
     } else {
         LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base;
         LZ4_streamHCPtr->internal_donotuse.base = NULL;
@@ -938,7 +947,7 @@ int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int
         dictionary += dictSize - 64 KB;
         dictSize = 64 KB;
     }
-    LZ4_resetStreamHC(LZ4_streamHCPtr, ctxPtr->compressionLevel);
+    LZ4_initStreamHC(LZ4_streamHCPtr, ctxPtr->compressionLevel);
     LZ4HC_init (ctxPtr, (const BYTE*)dictionary);
     ctxPtr->end = (const BYTE*)dictionary + dictSize;
     if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3);
@@ -1029,8 +1038,8 @@ int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictS
     {   U32 const endIndex = (U32)(streamPtr->end - streamPtr->base);
         streamPtr->end = (const BYTE*)safeBuffer + dictSize;
         streamPtr->base = streamPtr->end - endIndex;
-        streamPtr->dictLimit = endIndex - dictSize;
-        streamPtr->lowLimit = endIndex - dictSize;
+        streamPtr->dictLimit = endIndex - (U32)dictSize;
+        streamPtr->lowLimit = endIndex - (U32)dictSize;
         if (streamPtr->nextToUpdate < streamPtr->dictLimit) streamPtr->nextToUpdate = streamPtr->dictLimit;
     }
     return dictSize;
@@ -1061,7 +1070,7 @@ int LZ4_resetStreamStateHC(void* state, char* inputBuffer)
 {
     LZ4HC_CCtx_internal *ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
     if ((((size_t)state) & (sizeof(void*)-1)) != 0) return 1;   /* Error : pointer is not aligned for pointer (32 or 64 bits) */
-    LZ4_resetStreamHC((LZ4_streamHC_t*)state, ((LZ4_streamHC_t*)state)->internal_donotuse.compressionLevel);
+    LZ4_initStreamHC((LZ4_streamHC_t*)state, ((LZ4_streamHC_t*)state)->internal_donotuse.compressionLevel);
     LZ4HC_init(ctx, (const BYTE*)inputBuffer);
     return 0;
 }
@@ -1070,7 +1079,7 @@ void* LZ4_createHC (const char* inputBuffer)
 {
     LZ4_streamHC_t* hc4 = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
     if (hc4 == NULL) return NULL;   /* not enough memory */
-    LZ4_resetStreamHC(hc4, 0 /* compressionLevel */);
+    LZ4_initStreamHC(hc4, 0 /* compressionLevel */);
     LZ4HC_init (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
     return hc4;
 }
@@ -1102,7 +1111,7 @@ char* LZ4_slideInputBufferHC(void* LZ4HC_Data)
 
 
 /* ================================================
- * LZ4 Optimal parser (levels 10-12)
+ *  LZ4 Optimal parser (levels [LZ4HC_CLEVEL_OPT_MIN - LZ4HC_CLEVEL_MAX])
  * ===============================================*/
 typedef struct {
     int price;
@@ -1115,8 +1124,9 @@ typedef struct {
 LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen)
 {
     int price = litlen;
+    assert(litlen >= 0);
     if (litlen >= (int)RUN_MASK)
-        price += 1 + (litlen-RUN_MASK)/255;
+        price += 1 + ((litlen-(int)RUN_MASK) / 255);
     return price;
 }
 
@@ -1125,11 +1135,13 @@ LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen)
 LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen)
 {
     int price = 1 + 2 ; /* token + 16-bit offset */
+    assert(litlen >= 0);
+    assert(mlen >= MINMATCH);
 
     price += LZ4HC_literalsPrice(litlen);
 
     if (mlen >= (int)(ML_MASK+MINMATCH))
-        price += 1 + (mlen-(ML_MASK+MINMATCH))/255;
+        price += 1 + ((mlen-(int)(ML_MASK+MINMATCH)) / 255);
 
     return price;
 }
diff --git a/lib/lz4hc.h b/lib/lz4hc.h
index d1772f3..91b14ee 100644
--- a/lib/lz4hc.h
+++ b/lib/lz4hc.h
@@ -84,9 +84,9 @@ LZ4LIB_API int LZ4_compress_HC_extStateHC(void* stateHC, const char* src, char*
  *  Will compress as much data as possible from `src`
  *  to fit into `targetDstSize` budget.
  *  Result is provided in 2 parts :
- * @return : the number of bytes written into 'dst'
+ * @return : the number of bytes written into 'dst' (necessarily <= targetDstSize)
  *           or 0 if compression fails.
- * `srcSizePtr` : value will be updated to indicate how much bytes were read from `src`
+ * `srcSizePtr` : on success, *srcSizePtr is updated to indicate how much bytes were read from `src`
  */
 LZ4LIB_API int LZ4_compress_HC_destSize(void* stateHC,
                                   const char* src, char* dst,
@@ -103,8 +103,8 @@ LZ4LIB_API int LZ4_compress_HC_destSize(void* stateHC,
 /*! LZ4_createStreamHC() and LZ4_freeStreamHC() :
  *  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.
+ *  A same state can be used multiple times consecutively,
+ *  starting with LZ4_resetStreamHC_fast() to start a new stream of blocks.
  */
 LZ4LIB_API LZ4_streamHC_t* LZ4_createStreamHC(void);
 LZ4LIB_API int             LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr);
@@ -121,35 +121,38 @@ LZ4LIB_API int             LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr);
 
   Selecting the compression level can be done with LZ4_resetStreamHC_fast() (starts a new stream)
   or LZ4_setCompressionLevel() (anytime, between blocks in the same stream) (experimental).
-  LZ4_resetStreamHC_fast() only works on states which have been properly initialized at least once.
-
-  If state space is provided manually with no guarantee of its content, for example allocated on stack,
-  it must be fully initialized, using LZ4_resetStreamHC().
-  LZ4_resetStreamHC() is heavier, and it's guaranteed to succeed on any valid memory segment.
-  In contrast, LZ4_resetStreamHC_fast() only works on states which have been properly initialized at least once.
+  LZ4_resetStreamHC_fast() only works on states which have been properly initialized at least once,
+  which is automatically the case when state is created using LZ4_createStreamHC().
 
   After reset, a first "fictional block" can be designated as initial dictionary,
   using LZ4_loadDictHC() (Optional).
 
   Invoke LZ4_compress_HC_continue() to compress each successive block.
   The number of blocks is unlimited.
-  Previous input blocks (including initial dictionary when present) must remain accessible and unmodified during compression.
+  Previous input blocks, including initial dictionary when present,
+  must remain accessible and unmodified during compression.
+
+  It's allowed to update compression level anytime between blocks,
+  using LZ4_setCompressionLevel() (experimental).
 
-  'dst' buffer should be sized to handle worst case scenarios (see LZ4_compressBound()), ensuring compression success.
-  In case of failure, the API does not guarantee recovery, so the state _must_ be reset.
-  Whenever `dst` buffer size cannot be made >= LZ4_compressBound(),
-  consider using LZ4_compress_HC_continue_destSize() to ensure success.
+  'dst' buffer should be sized to handle worst case scenarios
+  (see LZ4_compressBound(), it ensures compression success).
+  In case of failure, the API does not guarantee recovery,
+  so the state _must_ be reset.
+  To ensure compression success
+  whenever `dst` buffer size cannot be made >= LZ4_compressBound(),
+  consider using LZ4_compress_HC_continue_destSize().
 
   Whenever previous input blocks can't be preserved unmodified in-place during compression of next blocks,
   it's possible to copy the last blocks into a more stable memory space, using LZ4_saveDictHC().
   Return value of LZ4_saveDictHC() is the size of dictionary effectively saved into 'safeBuffer' (<= 64 KB)
 
   After completing a streaming compression,
-  it's possible to start a new stream of blocks, and re-use the same LZ4_streamHC_t state 
-  by resetting it, using LZ4_resetStreamHC_fast().
+  it's possible to start a new stream of blocks, using the same LZ4_streamHC_t state,
+  just by resetting it, using LZ4_resetStreamHC_fast().
 */
 
-LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel);
+LZ4LIB_API void LZ4_resetStreamHC_fast(LZ4_streamHC_t* streamHCPtr, int compressionLevel);
 LZ4LIB_API int  LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize);
 
 LZ4LIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr,
@@ -239,22 +242,31 @@ struct LZ4HC_CCtx_internal
 #endif
 
 
-/* do not use these definitions directly.
- * allocate an LZ4_streamHC_t instead. */
+/* Do not use these definitions directly !
+ * Declare or allocate an LZ4_streamHC_t instead.
+ */
 #define LZ4_STREAMHCSIZE       (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56 + ((sizeof(void*)==16) ? 56 : 0) /* AS400*/ ) /* 262200 or 262256*/
 #define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t))
 union LZ4_streamHC_u {
     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.
+ * This can be used to allocate statically, on state, or as part of a larger structure.
+ *
+ * Such state **must** be initialized using LZ4_initStreamHC() before first use.
+ *
+ * Note that invoking LZ4_initStreamHC() is not required when
+ * the state was created using LZ4_createStreamHC() (which is recommended).
+ * Using the normal builder, a newly created state is automatically initialized.
  *
  * 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.
  */
 
+LZ4LIB_API void LZ4_initStreamHC (void* streamHCPtr, int compressionLevel);
+
 
 /*-************************************
 *  Deprecated Functions
@@ -264,11 +276,11 @@ union LZ4_streamHC_u {
 /* deprecated compression functions */
 LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC               (const char* source, char* dest, int inputSize);
 LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
-LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
-LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2              (const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_withStateHC               (void* state, const char* source, char* dest, int inputSize);
 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_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") LZ4LIB_API int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC2_withStateHC              (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
 LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API 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") LZ4LIB_API int LZ4_compressHC_continue               (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
 LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
@@ -284,12 +296,23 @@ LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_comp
 LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API void* LZ4_createHC (const char* inputBuffer);
 LZ4_DEPRECATED("use LZ4_saveDictHC() instead") LZ4LIB_API     char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
 LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") LZ4LIB_API   int   LZ4_freeHC (void* LZ4HC_Data);
-LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC2_continue               (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
 LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API 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") LZ4LIB_API int   LZ4_sizeofStreamStateHC(void);
 LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") LZ4LIB_API  int   LZ4_resetStreamStateHC(void* state, char* inputBuffer);
 
 
+/* LZ4_resetStreamHC() is now replaced by LZ4_initStreamHC().
+ * The intention is to emphasize the difference with LZ4_resetStreamHC_fast(),
+ * which is now the recommended function to start a new stream of blocks,
+ * but cannot be used to initialize a memory segment containing arbitrary garbage data.
+ *
+ * It is recommended to switch to LZ4_initStreamHC().
+ * LZ4_resetStreamHC() will generate deprecation warnings in a future version.
+ */
+LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel);
+
+
 #if defined (__cplusplus)
 }
 #endif