modified LZ4_initStreamHC() to look like LZ4_initStream()

it is now a pure initializer, for statically allocated states.
It can initialize any memory area, and because of this, requires size.

7 files changed, 119 insertions, 72 deletions

diff --git a/doc/lz4_manual.html b/doc/lz4_manual.html
index 5db3ec9..1c6dba7 100644
--- a/doc/lz4_manual.html
+++ b/doc/lz4_manual.html
@@ -159,19 +159,23 @@ int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int src
 </b><p>  Use this to prepare an LZ4_stream_t for a new chain of dependent blocks
   (e.g., LZ4_compress_fast_continue()).
 
-  An LZ4_stream_t must be initialized once.
+  An LZ4_stream_t must be initialized once before usage.
   This is automatically done when created by LZ4_createStream().
   However, should the LZ4_stream_t be simply declared on stack (for example),
-  it's necessary to initialize first using LZ4_initStream().
+  it's necessary to initialize it first, using LZ4_initStream().
 
-  After that, start any new stream with LZ4_resetStream_fast().
+  After init, start any new stream with LZ4_resetStream_fast().
   A same LZ4_stream_t can be re-used multiple times consecutively
   and compress multiple streams,
   provided that it starts each new stream with LZ4_resetStream_fast().
 
   LZ4_resetStream_fast() is much faster than LZ4_initStream(),
   but is not compatible with memory regions containing garbage data.
-  For this reason, LZ4_stream_t must be initialized at least once,
+
+  Note: it's only useful to call LZ4_resetStream_fast()
+        in the context of streaming compression.
+        The *extState* functions perform their own resets.
+        Invoking LZ4_resetStream_fast() before is redundant, and even counterproductive.
  
 </p></pre><BR>
 
@@ -382,13 +386,16 @@ union LZ4_stream_u {
 
 <pre><b>LZ4_stream_t* LZ4_initStream (void* buffer, size_t size);
 </b><p>  An LZ4_stream_t structure must be initialized at least once.
-  While this is automatically done when invoking LZ4_createStream(),
-  it's not when the structure is simply declared on stack (for example).
-  Use this function to properly initialize a newly declared LZ4_stream_t.
-  It can also accept any arbitrary buffer of sufficient size as input,
-  and will return a pointer of proper type upon initialization.
-  Note : initialization can fail if size < sizeof(LZ4_stream_t).
-  In which case, the function will @return NULL.
+  This is automatically done when invoking LZ4_createStream(),
+  but it's not when the structure is simply declared on stack (for example).
+
+  Use LZ4_initStream() to properly initialize a newly declared LZ4_stream_t.
+  It can also initialize any arbitrary buffer of sufficient size,
+  and will @return a pointer of proper type upon initialization.
+
+  Note : initialization fails if size and alignment conditions are not respected.
+         In which case, the function will @return NULL.
+  Note2: An LZ4_stream_t structure guarantees correct alignment and size.
  
 </p></pre><BR>
 
@@ -468,7 +475,7 @@ int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize,
  
 </p></pre><BR>
 
-<pre><b>//LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr);
+<pre><b>void LZ4_resetStream (LZ4_stream_t* streamPtr);
 </b><p>  An LZ4_stream_t structure must be initialized at least once.
   This is done with LZ4_initStream(), or LZ4_resetStream().
   Consider switching to LZ4_initStream(),
diff --git a/lib/lz4.c b/lib/lz4.c
index 5fbc7c7..34587ce 100644
--- a/lib/lz4.c
+++ b/lib/lz4.c
@@ -1299,6 +1299,7 @@ static size_t LZ4_stream_t_alignment(void)
 LZ4_stream_t* LZ4_initStream (void* buffer, size_t size)
 {
     DEBUGLOG(5, "LZ4_initStream");
+    if (buffer == NULL) return NULL;
     if (size < sizeof(LZ4_stream_t)) return NULL;
 #ifndef _MSC_VER  /* for some reason, Visual fails the aligment test on 32-bit x86 :
                      it reports an aligment of 8-bytes,
diff --git a/lib/lz4frame.c b/lib/lz4frame.c
index 3b4fcee..efe38da 100644
--- a/lib/lz4frame.c
+++ b/lib/lz4frame.c
@@ -630,7 +630,8 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
             if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
                 LZ4_initStream((LZ4_stream_t *) cctxPtr->lz4CtxPtr, sizeof (LZ4_stream_t));
             } else {
-                LZ4_initStreamHC((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
+                LZ4_initStreamHC((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, sizeof(LZ4_streamHC_t));
+                LZ4_setCompressionLevel((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
             }
             cctxPtr->lz4CtxState = ctxTypeID;
         }
diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index 9e8b77e..693337a 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -103,7 +103,7 @@ static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4)
     MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable));
 }
 
-static void LZ4HC_init (LZ4HC_CCtx_internal* hc4, const BYTE* start)
+static void LZ4HC_init_internal (LZ4HC_CCtx_internal* hc4, const BYTE* start)
 {
     uptrval startingOffset = (uptrval)(hc4->end - hc4->base);
     if (startingOffset > 1 GB) {
@@ -239,7 +239,7 @@ LZ4HC_InsertAndGetWiderMatch (
     const BYTE* const dictBase = hc4->dictBase;
     int const lookBackLength = (int)(ip-iLowLimit);
     int nbAttempts = maxNbAttempts;
-    int matchChainPos = 0;
+    U32 matchChainPos = 0;
     U32 const pattern = LZ4_read32(ip);
     U32 matchIndex;
     repeat_state_e repeat = rep_untested;
@@ -300,7 +300,7 @@ LZ4HC_InsertAndGetWiderMatch (
                     U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + (U32)pos);
                     if (candidateDist > distanceToNextMatch) {
                         distanceToNextMatch = candidateDist;
-                        matchChainPos = pos;
+                        matchChainPos = (U32)pos;
                 }   }
                 if (distanceToNextMatch > 1) {
                     if (distanceToNextMatch > matchIndex) break;   /* avoid overflow */
@@ -793,7 +793,7 @@ LZ4HC_compress_generic_dictCtx (
         limitedOutput_directive limit
         )
 {
-    const size_t position = ctx->end - ctx->base - ctx->lowLimit;
+    const size_t position = (size_t)(ctx->end - ctx->base) - ctx->lowLimit;
     assert(ctx->dictCtx != NULL);
     if (position >= 64 KB) {
         ctx->dictCtx = NULL;
@@ -827,14 +827,31 @@ LZ4HC_compress_generic (
 }
 
 
-int LZ4_sizeofStateHC(void) { return sizeof(LZ4_streamHC_t); }
+int LZ4_sizeofStateHC(void) { return (int)sizeof(LZ4_streamHC_t); }
 
+#ifndef _MSC_VER  /* for some reason, Visual fails the aligment test on 32-bit x86 :
+                   * it reports an aligment of 8-bytes,
+                   * while actually aligning LZ4_streamHC_t on 4 bytes. */
+static size_t LZ4_streamHC_t_alignment(void)
+{
+    struct { char c; LZ4_streamHC_t t; } t_a;
+    return sizeof(t_a) - sizeof(t_a.t);
+}
+#endif
+
+/* state is presumed correctly initialized,
+ * in which case its size and alignment have already been validate */
 int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
 {
     LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
+#ifndef _MSC_VER  /* for some reason, Visual fails the aligment test on 32-bit x86 :
+                   * it reports an aligment of 8-bytes,
+                   * while actually aligning LZ4_streamHC_t on 4 bytes. */
+    assert(((size_t)state & (LZ4_streamHC_t_alignment() - 1)) == 0);  /* check alignment */
+#endif
     if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0;   /* Error : state is not aligned for pointers (32 or 64 bits) */
     LZ4_resetStreamHC_fast((LZ4_streamHC_t*)state, compressionLevel);
-    LZ4HC_init (ctx, (const BYTE*)src);
+    LZ4HC_init_internal (ctx, (const BYTE*)src);
     if (dstCapacity < LZ4_compressBound(srcSize))
         return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput);
     else
@@ -843,8 +860,8 @@ 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_initStreamHC (state, compressionLevel);   /* full initialization, as there is no guarantee on state's content (could be freshly malloc'ed) */
+    LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx));
+    if (ctx==NULL) return 0;   /* init failure */
     return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel);
 }
 
@@ -863,12 +880,14 @@ int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, in
     return cSize;
 }
 
-int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel)
+/* state is presumed sized correctly (>= sizeof(LZ4_streamHC_t)) */
+int LZ4_compress_HC_destSize(void* state, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel)
 {
-    LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse;
-    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);
+    LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx));
+    if (ctx==NULL) return 0;   /* init failure */
+    LZ4HC_init_internal(&ctx->internal_donotuse, (const BYTE*) source);
+    LZ4_setCompressionLevel(ctx, cLevel);
+    return LZ4HC_compress_generic(&ctx->internal_donotuse, source, dest, sourceSizePtr, targetDestSize, cLevel, limitedDestSize);
 }
 
 
@@ -881,7 +900,7 @@ 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_initStreamHC(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);  /* full initialization, malloc'ed buffer can be full of garbage */
+    LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));  /* full initialization, malloc'ed buffer can be full of garbage */
     return LZ4_streamHCPtr;
 }
 
@@ -894,37 +913,48 @@ int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr)
 }
 
 
-/* initialization */
-void LZ4_initStreamHC (void* state, int compressionLevel)
+LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size)
 {
-    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 */
+    LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)buffer;
+    if (buffer == NULL) return NULL;
+    if (size < sizeof(LZ4_streamHC_t)) return NULL;
+#ifndef _MSC_VER  /* for some reason, Visual fails the aligment test on 32-bit x86 :
+                   * it reports an aligment of 8-bytes,
+                   * while actually aligning LZ4_streamHC_t on 4 bytes. */
+    if (((size_t)buffer) & (LZ4_streamHC_t_alignment() - 1)) return NULL;  /* alignment check */
+#endif
+    /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */
+    LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= LZ4_STREAMHCSIZE);
     DEBUGLOG(4, "LZ4_resetStreamHC(%p, %d)", LZ4_streamHCPtr, compressionLevel);
+    /* end-base will trigger a clearTable on starting compression */
     LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1;
     LZ4_streamHCPtr->internal_donotuse.base = NULL;
     LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
     LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = 0;
     LZ4_streamHCPtr->internal_donotuse.dirty = 0;
-    LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
+    LZ4_setCompressionLevel(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);
+    return LZ4_streamHCPtr;
 }
 
 /* just a stub */
 void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
 {
-    LZ4_initStreamHC(LZ4_streamHCPtr, compressionLevel);
+    LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
+    LZ4_setCompressionLevel(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_initStreamHC(LZ4_streamHCPtr, compressionLevel);
+        LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
     } else {
+        /* preserve end - base : can trigger clearTable's threshold */
         LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base;
         LZ4_streamHCPtr->internal_donotuse.base = NULL;
         LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
-        LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
     }
+    LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
 }
 
 void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
@@ -939,16 +969,19 @@ void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor)
     LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = (favor!=0);
 }
 
+/* LZ4_loadDictHC() :
+ * LZ4_streamHCPtr is presumed properly initialized */
 int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize)
 {
     LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
     DEBUGLOG(4, "LZ4_loadDictHC(%p, %p, %d)", LZ4_streamHCPtr, dictionary, dictSize);
+    assert(LZ4_streamHCPtr != NULL);
     if (dictSize > 64 KB) {
         dictionary += dictSize - 64 KB;
         dictSize = 64 KB;
     }
-    LZ4_initStreamHC(LZ4_streamHCPtr, ctxPtr->compressionLevel);
-    LZ4HC_init (ctxPtr, (const BYTE*)dictionary);
+    LZ4_resetStreamHC_fast(LZ4_streamHCPtr, ctxPtr->compressionLevel);
+    LZ4HC_init_internal (ctxPtr, (const BYTE*)dictionary);
     ctxPtr->end = (const BYTE*)dictionary + dictSize;
     if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3);
     return dictSize;
@@ -982,8 +1015,9 @@ static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr,
 {
     LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
     DEBUGLOG(4, "LZ4_compressHC_continue_generic(%p, %p, %d)", LZ4_streamHCPtr, src, *srcSizePtr);
+    assert(ctxPtr != NULL);
     /* auto-init if forgotten */
-    if (ctxPtr->base == NULL) LZ4HC_init (ctxPtr, (const BYTE*) src);
+    if (ctxPtr->base == NULL) LZ4HC_init_internal (ctxPtr, (const BYTE*) src);
 
     /* Check overflow */
     if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 GB) {
@@ -1046,11 +1080,13 @@ int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictS
 }
 
 
-/***********************************
+/***************************************************
 *  Deprecated Functions
-***********************************/
+***************************************************/
+
 /* These functions currently generate deprecation warnings */
-/* Deprecated compression functions */
+
+/* Wrappers for deprecated compression functions */
 int LZ4_compressHC(const char* src, char* dst, int srcSize) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), 0); }
 int LZ4_compressHC_limitedOutput(const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_HC(src, dst, srcSize, maxDstSize, 0); }
 int LZ4_compressHC2(const char* src, char* dst, int srcSize, int cLevel) { return LZ4_compress_HC (src, dst, srcSize, LZ4_compressBound(srcSize), cLevel); }
@@ -1066,25 +1102,26 @@ int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* ctx, const char* src,
 /* Deprecated streaming functions */
 int LZ4_sizeofStreamStateHC(void) { return LZ4_STREAMHCSIZE; }
 
+/* state is presumed correctly sized, aka >= sizeof(LZ4_streamHC_t)
+ * @return : 0 on success, !=0 if error */
 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_initStreamHC((LZ4_streamHC_t*)state, ((LZ4_streamHC_t*)state)->internal_donotuse.compressionLevel);
-    LZ4HC_init(ctx, (const BYTE*)inputBuffer);
+    LZ4_streamHC_t* const hc4 = LZ4_initStreamHC(state, sizeof(*hc4));
+    if (hc4 == NULL) return 1;   /* init failed */
+    LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
     return 0;
 }
 
 void* LZ4_createHC (const char* inputBuffer)
 {
-    LZ4_streamHC_t* hc4 = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
+    LZ4_streamHC_t* const hc4 = LZ4_createStreamHC();
     if (hc4 == NULL) return NULL;   /* not enough memory */
-    LZ4_initStreamHC(hc4, 0 /* compressionLevel */);
-    LZ4HC_init (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
+    LZ4HC_init_internal (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
     return hc4;
 }
 
-int LZ4_freeHC (void* LZ4HC_Data) {
+int LZ4_freeHC (void* LZ4HC_Data)
+{
     if (!LZ4HC_Data) return 0;  /* support free on NULL */
     FREEMEM(LZ4HC_Data);
     return 0;
diff --git a/lib/lz4hc.h b/lib/lz4hc.h
index fbf4518..445c126 100644
--- a/lib/lz4hc.h
+++ b/lib/lz4hc.h
@@ -265,7 +265,7 @@ union LZ4_streamHC_u {
  * Static allocation shall only be used in combination with static linking.
  */
 
-LZ4LIB_API void LZ4_initStreamHC (void* streamHCPtr, int compressionLevel);  /* v1.9.0+ */
+LZ4LIB_API LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size);
 
 
 /*-************************************
@@ -299,7 +299,7 @@ LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") LZ4LIB_API   int   LZ4_freeHC (
 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_DEPRECATED("use LZ4_initStreamHC() instead") LZ4LIB_API  int   LZ4_resetStreamStateHC(void* state, char* inputBuffer);
 
 
 /* LZ4_resetStreamHC() is now replaced by LZ4_initStreamHC().
@@ -310,7 +310,7 @@ LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") LZ4LIB_API  int   LZ4_resetStr
  * 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);
+//LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionLevel);
 
 
 #if defined (__cplusplus)
diff --git a/tests/fullbench.c b/tests/fullbench.c
index 34c9b7b..456c916 100644
--- a/tests/fullbench.c
+++ b/tests/fullbench.c
@@ -245,7 +245,7 @@ static int local_LZ4_compress_forceDict(const char* in, char* out, int inSize)
 LZ4_streamHC_t LZ4_streamHC;
 static void local_LZ4_resetStreamHC(void)
 {
-    LZ4_initStreamHC(&LZ4_streamHC, 0);
+    LZ4_initStreamHC(&LZ4_streamHC, sizeof(LZ4_streamHC));
 }
 
 static int local_LZ4_saveDictHC(const char* in, char* out, int inSize)
diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index d899cef..8828c06 100644
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -345,7 +345,8 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
         DISPLAY("Not enough memory to start fuzzer tests");
         goto _output_error;
     }
-    memset(&LZ4dict, 0, sizeof(LZ4dict));
+    if ( LZ4_initStream(&LZ4dict, sizeof(LZ4dict)) == NULL) abort();
+    if ( LZ4_initStreamHC(&LZ4dictHC, sizeof(LZ4dictHC)) == NULL) abort();
     {   U32 randState = coreRandState ^ PRIME3;
         FUZ_fillCompressibleNoiseBuffer(CNBuffer, COMPRESSIBLE_NOISE_LENGTH, compressibility, &randState);
     }
@@ -800,7 +801,7 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
         ret = LZ4_decompress_safe_usingDict(compressedBuffer, decodedBuffer, blockContinueCompressedSize, blockSize, dict, dictSize);
         FUZ_CHECKTEST(ret!=blockSize, "LZ4_decompress_safe_usingDict did not regenerate original data");
         FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_safe_usingDict overrun specified output buffer size");
-        {   U32 const crcCheck = XXH32(decodedBuffer, blockSize, 0);
+        {   U32 const crcCheck = XXH32(decodedBuffer, (size_t)blockSize, 0);
             FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_safe_usingDict corrupted decoded data");
         }
 
@@ -829,9 +830,8 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
         FUZ_DISPLAYTEST("LZ4_compress_HC_continue with an external dictionary");
         dict -= (FUZ_rand(&randState) & 7);    /* even bigger separation */
         if (dict < (char*)CNBuffer) dict = (char*)CNBuffer;
-        LZ4_initStreamHC (&LZ4dictHC, compressionLevel);
         LZ4_loadDictHC(&LZ4dictHC, dict, dictSize);
-        LZ4_setCompressionLevel(&LZ4dictHC, compressionLevel-1);
+        LZ4_setCompressionLevel (&LZ4dictHC, compressionLevel);
         blockContinueCompressedSize = LZ4_compress_HC_continue(&LZ4dictHC, block, compressedBuffer, blockSize, (int)compressedBufferSize);
         FUZ_CHECKTEST(blockContinueCompressedSize==0, "LZ4_compress_HC_continue failed");
         FUZ_CHECKTEST(LZ4dictHC.internal_donotuse.dirty, "Context should be clean");
@@ -863,11 +863,11 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
         FUZ_DISPLAYTEST();
         {
             LZ4_streamHC_t LZ4_streamHC;
+            LZ4_initStreamHC(&LZ4_streamHC, sizeof(LZ4_streamHC));
 
-            LZ4_initStreamHC (&LZ4dictHC, compressionLevel);
             LZ4_loadDictHC(&LZ4dictHC, dict, dictSize);
-            LZ4_initStreamHC (&LZ4_streamHC, compressionLevel);
             LZ4_attach_HC_dictionary(&LZ4_streamHC, &LZ4dictHC);
+            LZ4_setCompressionLevel (&LZ4_streamHC, compressionLevel);
             blockContinueCompressedSize = LZ4_compress_HC_continue(&LZ4_streamHC, block, compressedBuffer, blockSize, (int)compressedBufferSize);
             FUZ_CHECKTEST(blockContinueCompressedSize==0, "LZ4_compress_HC_continue with ExtDictCtx failed");
             FUZ_CHECKTEST(LZ4_streamHC.internal_donotuse.dirty, "Context should be clean");
@@ -894,25 +894,25 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
             FUZ_CHECKTEST(ret!=blockContinueCompressedSize, "LZ4_compress_HC_continue using ExtDictCtx and fast reset size is different (%i != %i)", ret, blockContinueCompressedSize);
             FUZ_CHECKTEST(ret<=0, "LZ4_compress_HC_continue using ExtDictCtx and fast reset should work : enough size available within output buffer");
             FUZ_CHECKTEST(LZ4_streamHC.internal_donotuse.dirty, "Context should be clean");
+        }
 
-            FUZ_DISPLAYTEST();
-            decodedBuffer[blockSize] = 0;
-            ret = LZ4_decompress_safe_usingDict(compressedBuffer, decodedBuffer, blockContinueCompressedSize, blockSize, dict, dictSize);
-            FUZ_CHECKTEST(ret!=blockSize, "LZ4_decompress_safe_usingDict did not regenerate original data");
-            FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_safe_usingDict overrun specified output buffer size");
-            {   U32 const crcCheck = XXH32(decodedBuffer, (size_t)blockSize, 0);
-                if (crcCheck!=crcOrig) FUZ_findDiff(block, decodedBuffer);
-                FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_safe_usingDict corrupted decoded data");
-            }
+        FUZ_DISPLAYTEST();
+        decodedBuffer[blockSize] = 0;
+        ret = LZ4_decompress_safe_usingDict(compressedBuffer, decodedBuffer, blockContinueCompressedSize, blockSize, dict, dictSize);
+        FUZ_CHECKTEST(ret!=blockSize, "LZ4_decompress_safe_usingDict did not regenerate original data");
+        FUZ_CHECKTEST(decodedBuffer[blockSize], "LZ4_decompress_safe_usingDict overrun specified output buffer size");
+        {   U32 const crcCheck = XXH32(decodedBuffer, (size_t)blockSize, 0);
+            if (crcCheck!=crcOrig) FUZ_findDiff(block, decodedBuffer);
+            FUZ_CHECKTEST(crcCheck!=crcOrig, "LZ4_decompress_safe_usingDict corrupted decoded data");
         }
 
         /* Compress HC continue destSize */
         FUZ_DISPLAYTEST();
-        {   int const availableSpace = (FUZ_rand(&randState) % blockSize) + 5;
+        {   int const availableSpace = (int)(FUZ_rand(&randState) % blockSize) + 5;
             int consumedSize = blockSize;
             FUZ_DISPLAYTEST();
-            LZ4_initStreamHC (&LZ4dictHC, compressionLevel);
             LZ4_loadDictHC(&LZ4dictHC, dict, dictSize);
+            LZ4_setCompressionLevel(&LZ4dictHC, compressionLevel);
             blockContinueCompressedSize = LZ4_compress_HC_continue_destSize(&LZ4dictHC, block, compressedBuffer, &consumedSize, availableSpace);
             DISPLAYLEVEL(5, " LZ4_compress_HC_continue_destSize : compressed %6i/%6i into %6i/%6i at cLevel=%i\n", consumedSize, blockSize, blockContinueCompressedSize, availableSpace, compressionLevel);
             FUZ_CHECKTEST(blockContinueCompressedSize==0, "LZ4_compress_HC_continue_destSize failed");
@@ -1067,6 +1067,7 @@ static void FUZ_unitTests(int compressionLevel)
     {   LZ4_streamHC_t sHC;   /* statically allocated */
         U64 crcOrig;
         int result;
+        LZ4_initStreamHC(&sHC, sizeof(sHC));
 
         /* Allocation test */
         DISPLAYLEVEL(3, " Basic HC allocation : ");
@@ -1079,7 +1080,7 @@ static void FUZ_unitTests(int compressionLevel)
         /* simple HC compression test */
         DISPLAYLEVEL(3, " Simple HC round-trip : ");
         {   U64 const crc64 = XXH64(testInput, testCompressedSize, 0);
-            LZ4_initStreamHC(&sHC, compressionLevel);
+            LZ4_setCompressionLevel(&sHC, compressionLevel);
             result = LZ4_compress_HC_continue(&sHC, testInput, testCompressed, testCompressedSize, testCompressedSize-1);
             FUZ_CHECKTEST(result==0, "LZ4_compressHC_limitedOutput_continue() compression failed");
             FUZ_CHECKTEST(sHC.internal_donotuse.dirty, "Context should be clean");
@@ -1104,7 +1105,7 @@ static void FUZ_unitTests(int compressionLevel)
             memset(block, 0, blockSize);
             ((char*)dstBlock)[targetSize] = sentinel;
 
-            LZ4_initStreamHC(&sHC, 3);
+            LZ4_resetStreamHC_fast(&sHC, 3);
             assert(blockSize < INT_MAX);
             srcSize = (int)blockSize;
             assert(targetSize < INT_MAX);