Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2078 insertions, 0 deletions

diff --git a/mfbt/lz4/lz4frame.c b/mfbt/lz4/lz4frame.c
new file mode 100644
index 0000000000..174f9ae4f2
--- /dev/null
+++ b/mfbt/lz4/lz4frame.c
@@ -0,0 +1,2078 @@
+/*
+ * 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 (malloc, free)
+ * provided either by <stdlib.h>,
+ * or redirected towards another library of user's choice
+ * (see Memory Routines below).
+ */
+
+
+/*-************************************
+*  Compiler Options
+**************************************/
+#ifdef _MSC_VER    /* Visual Studio */
+#  pragma warning(disable : 4127)   /* disable: C4127: conditional expression is constant */
+#endif
+
+
+/*-************************************
+*  Tuning parameters
+**************************************/
+/*
+ * LZ4F_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 LZ4F_HEAPMODE
+#  define LZ4F_HEAPMODE 0
+#endif
+
+
+/*-************************************
+*  Library declarations
+**************************************/
+#define LZ4F_STATIC_LINKING_ONLY
+#include "lz4frame.h"
+#define LZ4_STATIC_LINKING_ONLY
+#include "lz4.h"
+#define LZ4_HC_STATIC_LINKING_ONLY
+#include "lz4hc.h"
+#define XXH_STATIC_LINKING_ONLY
+#include "xxhash.h"
+
+
+/*-************************************
+*  Memory routines
+**************************************/
+/*
+ * User may redirect invocations of
+ * malloc(), calloc() and free()
+ * towards another library or solution of their choice
+ * by modifying below section.
+**/
+
+#include <string.h>   /* memset, memcpy, memmove */
+#ifndef LZ4_SRC_INCLUDED  /* avoid redefinition when sources are coalesced */
+#  define MEM_INIT(p,v,s)   memset((p),(v),(s))
+#endif
+
+#ifndef LZ4_SRC_INCLUDED   /* avoid redefinition when sources are coalesced */
+#  include <stdlib.h>   /* malloc, calloc, free */
+#  define ALLOC(s)          malloc(s)
+#  define ALLOC_AND_ZERO(s) calloc(1,(s))
+#  define FREEMEM(p)        free(p)
+#endif
+
+static void* LZ4F_calloc(size_t s, LZ4F_CustomMem cmem)
+{
+    /* custom calloc defined : use it */
+    if (cmem.customCalloc != NULL) {
+        return cmem.customCalloc(cmem.opaqueState, s);
+    }
+    /* nothing defined : use default <stdlib.h>'s calloc() */
+    if (cmem.customAlloc == NULL) {
+        return ALLOC_AND_ZERO(s);
+    }
+    /* only custom alloc defined : use it, and combine it with memset() */
+    {   void* const p = cmem.customAlloc(cmem.opaqueState, s);
+        if (p != NULL) MEM_INIT(p, 0, s);
+        return p;
+}   }
+
+static void* LZ4F_malloc(size_t s, LZ4F_CustomMem cmem)
+{
+    /* custom malloc defined : use it */
+    if (cmem.customAlloc != NULL) {
+        return cmem.customAlloc(cmem.opaqueState, s);
+    }
+    /* nothing defined : use default <stdlib.h>'s malloc() */
+    return ALLOC(s);
+}
+
+static void LZ4F_free(void* p, LZ4F_CustomMem cmem)
+{
+    /* custom malloc defined : use it */
+    if (cmem.customFree != NULL) {
+        cmem.customFree(cmem.opaqueState, p);
+        return;
+    }
+    /* nothing defined : use default <stdlib.h>'s free() */
+    FREEMEM(p);
+}
+
+
+/*-************************************
+*  Debug
+**************************************/
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1)
+#  include <assert.h>
+#else
+#  ifndef assert
+#    define assert(condition) ((void)0)
+#  endif
+#endif
+
+#define LZ4F_STATIC_ASSERT(c)    { enum { LZ4F_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
+
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2) && !defined(DEBUGLOG)
+#  include <stdio.h>
+static int g_debuglog_enable = 1;
+#  define DEBUGLOG(l, ...) {                                  \
+                if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) {  \
+                    fprintf(stderr, __FILE__ ": ");           \
+                    fprintf(stderr, __VA_ARGS__);             \
+                    fprintf(stderr, " \n");                   \
+            }   }
+#else
+#  define DEBUGLOG(l, ...)      {}    /* disabled */
+#endif
+
+
+/*-************************************
+*  Basic Types
+**************************************/
+#if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
+# include <stdint.h>
+  typedef  uint8_t BYTE;
+  typedef uint16_t U16;
+  typedef uint32_t U32;
+  typedef  int32_t S32;
+  typedef uint64_t U64;
+#else
+  typedef unsigned char       BYTE;
+  typedef unsigned short      U16;
+  typedef unsigned int        U32;
+  typedef   signed int        S32;
+  typedef unsigned long long  U64;
+#endif
+
+
+/* unoptimized version; solves endianness & alignment issues */
+static U32 LZ4F_readLE32 (const void* src)
+{
+    const BYTE* const srcPtr = (const BYTE*)src;
+    U32 value32 = srcPtr[0];
+    value32 += ((U32)srcPtr[1])<< 8;
+    value32 += ((U32)srcPtr[2])<<16;
+    value32 += ((U32)srcPtr[3])<<24;
+    return value32;
+}
+
+static void LZ4F_writeLE32 (void* dst, U32 value32)
+{
+    BYTE* const dstPtr = (BYTE*)dst;
+    dstPtr[0] = (BYTE)value32;
+    dstPtr[1] = (BYTE)(value32 >> 8);
+    dstPtr[2] = (BYTE)(value32 >> 16);
+    dstPtr[3] = (BYTE)(value32 >> 24);
+}
+
+static U64 LZ4F_readLE64 (const void* src)
+{
+    const BYTE* const srcPtr = (const BYTE*)src;
+    U64 value64 = srcPtr[0];
+    value64 += ((U64)srcPtr[1]<<8);
+    value64 += ((U64)srcPtr[2]<<16);
+    value64 += ((U64)srcPtr[3]<<24);
+    value64 += ((U64)srcPtr[4]<<32);
+    value64 += ((U64)srcPtr[5]<<40);
+    value64 += ((U64)srcPtr[6]<<48);
+    value64 += ((U64)srcPtr[7]<<56);
+    return value64;
+}
+
+static void LZ4F_writeLE64 (void* dst, U64 value64)
+{
+    BYTE* const dstPtr = (BYTE*)dst;
+    dstPtr[0] = (BYTE)value64;
+    dstPtr[1] = (BYTE)(value64 >> 8);
+    dstPtr[2] = (BYTE)(value64 >> 16);
+    dstPtr[3] = (BYTE)(value64 >> 24);
+    dstPtr[4] = (BYTE)(value64 >> 32);
+    dstPtr[5] = (BYTE)(value64 >> 40);
+    dstPtr[6] = (BYTE)(value64 >> 48);
+    dstPtr[7] = (BYTE)(value64 >> 56);
+}
+
+
+/*-************************************
+*  Constants
+**************************************/
+#ifndef LZ4_SRC_INCLUDED   /* avoid double definition */
+#  define KB *(1<<10)
+#  define MB *(1<<20)
+#  define GB *(1<<30)
+#endif
+
+#define _1BIT  0x01
+#define _2BITS 0x03
+#define _3BITS 0x07
+#define _4BITS 0x0F
+#define _8BITS 0xFF
+
+#define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U
+#define LZ4F_BLOCKSIZEID_DEFAULT LZ4F_max64KB
+
+static const size_t minFHSize = LZ4F_HEADER_SIZE_MIN;   /*  7 */
+static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX;   /* 19 */
+static const size_t BHSize = LZ4F_BLOCK_HEADER_SIZE;  /* block header : size, and compress flag */
+static const size_t BFSize = LZ4F_BLOCK_CHECKSUM_SIZE;  /* block footer : checksum (optional) */
+
+
+/*-************************************
+*  Structures and local types
+**************************************/
+
+typedef enum { LZ4B_COMPRESSED, LZ4B_UNCOMPRESSED} LZ4F_blockCompression_t;
+
+typedef struct LZ4F_cctx_s
+{
+    LZ4F_CustomMem cmem;
+    LZ4F_preferences_t prefs;
+    U32    version;
+    U32    cStage;
+    const LZ4F_CDict* cdict;
+    size_t maxBlockSize;
+    size_t maxBufferSize;
+    BYTE*  tmpBuff;    /* internal buffer, for streaming */
+    BYTE*  tmpIn;      /* starting position of data compress within internal buffer (>= tmpBuff) */
+    size_t tmpInSize;  /* amount of data to compress after tmpIn */
+    U64    totalInSize;
+    XXH32_state_t xxh;
+    void*  lz4CtxPtr;
+    U16    lz4CtxAlloc; /* sized for: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
+    U16    lz4CtxState; /* in use as: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
+    LZ4F_blockCompression_t  blockCompression;
+} LZ4F_cctx_t;
+
+
+/*-************************************
+*  Error management
+**************************************/
+#define LZ4F_GENERATE_STRING(STRING) #STRING,
+static const char* LZ4F_errorStrings[] = { LZ4F_LIST_ERRORS(LZ4F_GENERATE_STRING) };
+
+
+unsigned LZ4F_isError(LZ4F_errorCode_t code)
+{
+    return (code > (LZ4F_errorCode_t)(-LZ4F_ERROR_maxCode));
+}
+
+const char* LZ4F_getErrorName(LZ4F_errorCode_t code)
+{
+    static const char* codeError = "Unspecified error code";
+    if (LZ4F_isError(code)) return LZ4F_errorStrings[-(int)(code)];
+    return codeError;
+}
+
+LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult)
+{
+    if (!LZ4F_isError(functionResult)) return LZ4F_OK_NoError;
+    return (LZ4F_errorCodes)(-(ptrdiff_t)functionResult);
+}
+
+static LZ4F_errorCode_t LZ4F_returnErrorCode(LZ4F_errorCodes code)
+{
+    /* 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;
+}
+
+#define RETURN_ERROR(e) return LZ4F_returnErrorCode(LZ4F_ERROR_ ## e)
+
+#define RETURN_ERROR_IF(c,e) if (c) RETURN_ERROR(e)
+
+#define FORWARD_IF_ERROR(r)  if (LZ4F_isError(r)) return (r)
+
+unsigned LZ4F_getVersion(void) { return LZ4F_VERSION; }
+
+int LZ4F_compressionLevel_max(void) { return LZ4HC_CLEVEL_MAX; }
+
+size_t LZ4F_getBlockSize(LZ4F_blockSizeID_t blockSizeID)
+{
+    static const size_t blockSizes[4] = { 64 KB, 256 KB, 1 MB, 4 MB };
+
+    if (blockSizeID == 0) blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT;
+    if (blockSizeID < LZ4F_max64KB || blockSizeID > LZ4F_max4MB)
+        RETURN_ERROR(maxBlockSize_invalid);
+    {   int const blockSizeIdx = (int)blockSizeID - (int)LZ4F_max64KB;
+        return blockSizes[blockSizeIdx];
+}   }
+
+/*-************************************
+*  Private functions
+**************************************/
+#define MIN(a,b)   ( (a) < (b) ? (a) : (b) )
+
+static BYTE LZ4F_headerChecksum (const void* header, size_t length)
+{
+    U32 const xxh = XXH32(header, length, 0);
+    return (BYTE)(xxh >> 8);
+}
+
+
+/*-************************************
+*  Simple-pass compression functions
+**************************************/
+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;
+    while (requestedBSID > proposedBSID) {
+        if (srcSize <= maxBlockSize)
+            return proposedBSID;
+        proposedBSID = (LZ4F_blockSizeID_t)((int)proposedBSID + 1);
+        maxBlockSize <<= 2;
+    }
+    return requestedBSID;
+}
+
+/*! 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)
+{
+    LZ4F_preferences_t prefsNull = LZ4F_INIT_PREFERENCES;
+    prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled;   /* worst case */
+    prefsNull.frameInfo.blockChecksumFlag = LZ4F_blockChecksumEnabled;   /* worst case */
+    {   const LZ4F_preferences_t* const prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr;
+        U32 const flush = prefsPtr->autoFlush | (srcSize==0);
+        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;
+        unsigned const nbFullBlocks = (unsigned)(maxSrcSize / blockSize);
+        size_t const partialBlockSize = maxSrcSize & (blockSize-1);
+        size_t const lastBlockSize = flush ? partialBlockSize : 0;
+        unsigned const nbBlocks = nbFullBlocks + (lastBlockSize>0);
+
+        size_t const blockCRCSize = BFSize * prefsPtr->frameInfo.blockChecksumFlag;
+        size_t const frameEnd = BHSize + (prefsPtr->frameInfo.contentChecksumFlag*BFSize);
+
+        return ((BHSize + 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 optional fields */
+
+    if (preferencesPtr!=NULL) prefs = *preferencesPtr;
+    else MEM_INIT(&prefs, 0, sizeof(prefs));
+    prefs.autoFlush = 1;
+
+    return headerSize + LZ4F_compressBound_internal(srcSize, &prefs, 0);;
+}
+
+
+/*! 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(LZ4F_cctx* cctx,
+                                     void* dstBuffer, size_t dstCapacity,
+                               const void* srcBuffer, size_t srcSize,
+                               const LZ4F_CDict* cdict,
+                               const LZ4F_preferences_t* preferencesPtr)
+{
+    LZ4F_preferences_t prefs;
+    LZ4F_compressOptions_t options;
+    BYTE* const dstStart = (BYTE*) dstBuffer;
+    BYTE* dstPtr = dstStart;
+    BYTE* const dstEnd = dstStart + dstCapacity;
+
+    if (preferencesPtr!=NULL)
+        prefs = *preferencesPtr;
+    else
+        MEM_INIT(&prefs, 0, sizeof(prefs));
+    if (prefs.frameInfo.contentSize != 0)
+        prefs.frameInfo.contentSize = (U64)srcSize;   /* auto-correct content size if selected (!=0) */
+
+    prefs.frameInfo.blockSizeID = LZ4F_optimalBSID(prefs.frameInfo.blockSizeID, srcSize);
+    prefs.autoFlush = 1;
+    if (srcSize <= LZ4F_getBlockSize(prefs.frameInfo.blockSizeID))
+        prefs.frameInfo.blockMode = LZ4F_blockIndependent;   /* only one block => no need for inter-block link */
+
+    MEM_INIT(&options, 0, sizeof(options));
+    options.stableSrc = 1;
+
+    RETURN_ERROR_IF(dstCapacity < LZ4F_compressFrameBound(srcSize, &prefs), dstMaxSize_tooSmall);
+
+    { size_t const headerSize = LZ4F_compressBegin_usingCDict(cctx, dstBuffer, dstCapacity, cdict, &prefs);  /* write header */
+      FORWARD_IF_ERROR(headerSize);
+      dstPtr += headerSize;   /* header size */ }
+
+    assert(dstEnd >= dstPtr);
+    { size_t const cSize = LZ4F_compressUpdate(cctx, dstPtr, (size_t)(dstEnd-dstPtr), srcBuffer, srcSize, &options);
+      FORWARD_IF_ERROR(cSize);
+      dstPtr += cSize; }
+
+    assert(dstEnd >= dstPtr);
+    { size_t const tailSize = LZ4F_compressEnd(cctx, dstPtr, (size_t)(dstEnd-dstPtr), &options);   /* flush last block, and generate suffix */
+      FORWARD_IF_ERROR(tailSize);
+      dstPtr += tailSize; }
+
+    assert(dstEnd >= dstStart);
+    return (size_t)(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)
+{
+    size_t result;
+#if (LZ4F_HEAPMODE)
+    LZ4F_cctx_t* cctxPtr;
+    result = LZ4F_createCompressionContext(&cctxPtr, LZ4F_VERSION);
+    FORWARD_IF_ERROR(result);
+#else
+    LZ4F_cctx_t cctx;
+    LZ4_stream_t lz4ctx;
+    LZ4F_cctx_t* const cctxPtr = &cctx;
+
+    MEM_INIT(&cctx, 0, sizeof(cctx));
+    cctx.version = LZ4F_VERSION;
+    cctx.maxBufferSize = 5 MB;   /* mess with real buffer size to prevent dynamic allocation; works only because autoflush==1 & stableSrc==1 */
+    if ( preferencesPtr == NULL
+      || preferencesPtr->compressionLevel < LZ4HC_CLEVEL_MIN ) {
+        LZ4_initStream(&lz4ctx, sizeof(lz4ctx));
+        cctxPtr->lz4CtxPtr = &lz4ctx;
+        cctxPtr->lz4CtxAlloc = 1;
+        cctxPtr->lz4CtxState = 1;
+    }
+#endif
+    DEBUGLOG(4, "LZ4F_compressFrame");
+
+    result = LZ4F_compressFrame_usingCDict(cctxPtr, dstBuffer, dstCapacity,
+                                           srcBuffer, srcSize,
+                                           NULL, preferencesPtr);
+
+#if (LZ4F_HEAPMODE)
+    LZ4F_freeCompressionContext(cctxPtr);
+#else
+    if ( preferencesPtr != NULL
+      && preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN ) {
+        LZ4F_free(cctxPtr->lz4CtxPtr, cctxPtr->cmem);
+    }
+#endif
+    return result;
+}
+
+
+/*-***************************************************
+*   Dictionary compression
+*****************************************************/
+
+struct LZ4F_CDict_s {
+    LZ4F_CustomMem cmem;
+    void* dictContent;
+    LZ4_stream_t* fastCtx;
+    LZ4_streamHC_t* HCCtx;
+}; /* typedef'd to LZ4F_CDict within lz4frame_static.h */
+
+LZ4F_CDict*
+LZ4F_createCDict_advanced(LZ4F_CustomMem cmem, const void* dictBuffer, size_t dictSize)
+{
+    const char* dictStart = (const char*)dictBuffer;
+    LZ4F_CDict* const cdict = (LZ4F_CDict*)LZ4F_malloc(sizeof(*cdict), cmem);
+    DEBUGLOG(4, "LZ4F_createCDict_advanced");
+    if (!cdict) return NULL;
+    cdict->cmem = cmem;
+    if (dictSize > 64 KB) {
+        dictStart += dictSize - 64 KB;
+        dictSize = 64 KB;
+    }
+    cdict->dictContent = LZ4F_malloc(dictSize, cmem);
+    cdict->fastCtx = (LZ4_stream_t*)LZ4F_malloc(sizeof(LZ4_stream_t), cmem);
+    if (cdict->fastCtx)
+        LZ4_initStream(cdict->fastCtx, sizeof(LZ4_stream_t));
+    cdict->HCCtx = (LZ4_streamHC_t*)LZ4F_malloc(sizeof(LZ4_streamHC_t), cmem);
+    if (cdict->HCCtx)
+        LZ4_initStream(cdict->HCCtx, sizeof(LZ4_streamHC_t));
+    if (!cdict->dictContent || !cdict->fastCtx || !cdict->HCCtx) {
+        LZ4F_freeCDict(cdict);
+        return NULL;
+    }
+    memcpy(cdict->dictContent, dictStart, dictSize);
+    LZ4_loadDict (cdict->fastCtx, (const char*)cdict->dictContent, (int)dictSize);
+    LZ4_setCompressionLevel(cdict->HCCtx, LZ4HC_CLEVEL_DEFAULT);
+    LZ4_loadDictHC(cdict->HCCtx, (const char*)cdict->dictContent, (int)dictSize);
+    return cdict;
+}
+
+/*! 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)
+{
+    DEBUGLOG(4, "LZ4F_createCDict");
+    return LZ4F_createCDict_advanced(LZ4F_defaultCMem, dictBuffer, dictSize);
+}
+
+void LZ4F_freeCDict(LZ4F_CDict* cdict)
+{
+    if (cdict==NULL) return;  /* support free on NULL */
+    LZ4F_free(cdict->dictContent, cdict->cmem);
+    LZ4F_free(cdict->fastCtx, cdict->cmem);
+    LZ4F_free(cdict->HCCtx, cdict->cmem);
+    LZ4F_free(cdict, cdict->cmem);
+}
+
+
+/*-*********************************
+*  Advanced compression functions
+***********************************/
+
+LZ4F_cctx*
+LZ4F_createCompressionContext_advanced(LZ4F_CustomMem customMem, unsigned version)
+{
+    LZ4F_cctx* const cctxPtr =
+        (LZ4F_cctx*)LZ4F_calloc(sizeof(LZ4F_cctx), customMem);
+    if (cctxPtr==NULL) return NULL;
+
+    cctxPtr->cmem = customMem;
+    cctxPtr->version = version;
+    cctxPtr->cStage = 0;   /* Uninitialized. Next stage : init cctx */
+
+    return cctxPtr;
+}
+
+/*! 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 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_cctx** LZ4F_compressionContextPtr, unsigned version)
+{
+    assert(LZ4F_compressionContextPtr != NULL); /* considered a violation of narrow contract */
+    /* in case it nonetheless happen in production */
+    RETURN_ERROR_IF(LZ4F_compressionContextPtr == NULL, parameter_null);
+
+    *LZ4F_compressionContextPtr = LZ4F_createCompressionContext_advanced(LZ4F_defaultCMem, version);
+    RETURN_ERROR_IF(*LZ4F_compressionContextPtr==NULL, allocation_failed);
+    return LZ4F_OK_NoError;
+}
+
+
+LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctxPtr)
+{
+    if (cctxPtr != NULL) {  /* support free on NULL */
+       LZ4F_free(cctxPtr->lz4CtxPtr, cctxPtr->cmem);  /* note: LZ4_streamHC_t and LZ4_stream_t are simple POD types */
+       LZ4F_free(cctxPtr->tmpBuff, cctxPtr->cmem);
+       LZ4F_free(cctxPtr, cctxPtr->cmem);
+    }
+    return LZ4F_OK_NoError;
+}
+
+
+/**
+ * This function prepares the internal LZ4(HC) stream for a new compression,
+ * resetting the context and attaching the dictionary, if there is one.
+ *
+ * It needs to be called at the beginning of each independent compression
+ * stream (i.e., at the beginning of a frame in blockLinked mode, or at the
+ * beginning of each block in blockIndependent mode).
+ */
+static void LZ4F_initStream(void* ctx,
+                            const LZ4F_CDict* cdict,
+                            int level,
+                            LZ4F_blockMode_t blockMode) {
+    if (level < LZ4HC_CLEVEL_MIN) {
+        if (cdict != NULL || blockMode == LZ4F_blockLinked) {
+            /* In these cases, we will call LZ4_compress_fast_continue(),
+             * which needs an already reset context. Otherwise, we'll call a
+             * one-shot API. The non-continued APIs internally perform their own
+             * resets at the beginning of their calls, where they know what
+             * tableType they need the context to be in. So in that case this
+             * would be misguided / wasted work. */
+            LZ4_resetStream_fast((LZ4_stream_t*)ctx);
+        }
+        LZ4_attach_dictionary((LZ4_stream_t *)ctx, cdict ? cdict->fastCtx : NULL);
+    } else {
+        LZ4_resetStreamHC_fast((LZ4_streamHC_t*)ctx, level);
+        LZ4_attach_HC_dictionary((LZ4_streamHC_t *)ctx, cdict ? cdict->HCCtx : NULL);
+    }
+}
+
+static int ctxTypeID_to_size(int ctxTypeID) {
+    switch(ctxTypeID) {
+    case 1:
+        return LZ4_sizeofState();
+    case 2:
+        return LZ4_sizeofStateHC();
+    default:
+        return 0;
+    }
+}
+
+/*! LZ4F_compressBegin_usingCDict() :
+ *  init streaming compression AND writes frame header into @dstBuffer.
+ * @dstCapacity 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_usingCDict(LZ4F_cctx* cctxPtr,
+                          void* dstBuffer, size_t dstCapacity,
+                          const LZ4F_CDict* cdict,
+                          const LZ4F_preferences_t* preferencesPtr)
+{
+    LZ4F_preferences_t const prefNull = LZ4F_INIT_PREFERENCES;
+    BYTE* const dstStart = (BYTE*)dstBuffer;
+    BYTE* dstPtr = dstStart;
+
+    RETURN_ERROR_IF(dstCapacity < maxFHSize, dstMaxSize_tooSmall);
+    if (preferencesPtr == NULL) preferencesPtr = &prefNull;
+    cctxPtr->prefs = *preferencesPtr;
+
+    /* cctx Management */
+    {   U16 const ctxTypeID = (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) ? 1 : 2;
+        int requiredSize = ctxTypeID_to_size(ctxTypeID);
+        int allocatedSize = ctxTypeID_to_size(cctxPtr->lz4CtxAlloc);
+        if (allocatedSize < requiredSize) {
+            /* not enough space allocated */
+            LZ4F_free(cctxPtr->lz4CtxPtr, cctxPtr->cmem);
+            if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
+                /* must take ownership of memory allocation,
+                 * in order to respect custom allocator contract */
+                cctxPtr->lz4CtxPtr = LZ4F_malloc(sizeof(LZ4_stream_t), cctxPtr->cmem);
+                if (cctxPtr->lz4CtxPtr)
+                    LZ4_initStream(cctxPtr->lz4CtxPtr, sizeof(LZ4_stream_t));
+            } else {
+                cctxPtr->lz4CtxPtr = LZ4F_malloc(sizeof(LZ4_streamHC_t), cctxPtr->cmem);
+                if (cctxPtr->lz4CtxPtr)
+                    LZ4_initStreamHC(cctxPtr->lz4CtxPtr, sizeof(LZ4_streamHC_t));
+            }
+            RETURN_ERROR_IF(cctxPtr->lz4CtxPtr == NULL, allocation_failed);
+            cctxPtr->lz4CtxAlloc = ctxTypeID;
+            cctxPtr->lz4CtxState = ctxTypeID;
+        } else if (cctxPtr->lz4CtxState != ctxTypeID) {
+            /* otherwise, a sufficient buffer is already allocated,
+             * but we need to reset it to the correct context type */
+            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, sizeof(LZ4_streamHC_t));
+                LZ4_setCompressionLevel((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
+            }
+            cctxPtr->lz4CtxState = ctxTypeID;
+    }   }
+
+    /* Buffer Management */
+    if (cctxPtr->prefs.frameInfo.blockSizeID == 0)
+        cctxPtr->prefs.frameInfo.blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT;
+    cctxPtr->maxBlockSize = LZ4F_getBlockSize(cctxPtr->prefs.frameInfo.blockSizeID);
+
+    {   size_t const requiredBuffSize = preferencesPtr->autoFlush ?
+                ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 64 KB : 0) :  /* only needs past data up to window size */
+                cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 128 KB : 0);
+
+        if (cctxPtr->maxBufferSize < requiredBuffSize) {
+            cctxPtr->maxBufferSize = 0;
+            LZ4F_free(cctxPtr->tmpBuff, cctxPtr->cmem);
+            cctxPtr->tmpBuff = (BYTE*)LZ4F_calloc(requiredBuffSize, cctxPtr->cmem);
+            RETURN_ERROR_IF(cctxPtr->tmpBuff == NULL, allocation_failed);
+            cctxPtr->maxBufferSize = requiredBuffSize;
+    }   }
+    cctxPtr->tmpIn = cctxPtr->tmpBuff;
+    cctxPtr->tmpInSize = 0;
+    (void)XXH32_reset(&(cctxPtr->xxh), 0);
+
+    /* context init */
+    cctxPtr->cdict = cdict;
+    if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) {
+        /* frame init only for blockLinked : blockIndependent will be init at each block */
+        LZ4F_initStream(cctxPtr->lz4CtxPtr, cdict, cctxPtr->prefs.compressionLevel, LZ4F_blockLinked);
+    }
+    if (preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN) {
+        LZ4_favorDecompressionSpeed((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, (int)preferencesPtr->favorDecSpeed);
+    }
+
+    /* Magic Number */
+    LZ4F_writeLE32(dstPtr, LZ4F_MAGICNUMBER);
+    dstPtr += 4;
+    {   BYTE* const headerStart = dstPtr;
+
+        /* FLG Byte */
+        *dstPtr++ = (BYTE)(((1 & _2BITS) << 6)    /* Version('01') */
+            + ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5)
+            + ((cctxPtr->prefs.frameInfo.blockChecksumFlag & _1BIT ) << 4)
+            + ((unsigned)(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 */
+        if (cctxPtr->prefs.frameInfo.contentSize) {
+            LZ4F_writeLE64(dstPtr, cctxPtr->prefs.frameInfo.contentSize);
+            dstPtr += 8;
+            cctxPtr->totalInSize = 0;
+        }
+        /* 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, (size_t)(dstPtr - headerStart));
+        dstPtr++;
+    }
+
+    cctxPtr->cStage = 1;   /* header written, now request input data block */
+    return (size_t)(dstPtr - dstStart);
+}
+
+
+/*! LZ4F_compressBegin() :
+ *  init streaming compression AND writes frame header into @dstBuffer.
+ * @dstCapacity 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 minimum capacity of dstBuffer for a given srcSize to handle worst case scenario.
+ *  LZ4F_preferences_t structure is optional : if NULL, preferences will be set to cover worst case scenario.
+ *  This function cannot fail.
+ */
+size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
+{
+    if (preferencesPtr && preferencesPtr->autoFlush) {
+        return LZ4F_compressBound_internal(srcSize, preferencesPtr, 0);
+    }
+    return LZ4F_compressBound_internal(srcSize, preferencesPtr, (size_t)-1);
+}
+
+
+typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level, const LZ4F_CDict* cdict);
+
+
+/*! LZ4F_makeBlock():
+ *  compress a single block, add header and optional checksum.
+ *  assumption : dst buffer capacity is >= BHSize + srcSize + crcSize
+ */
+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)
+{
+    BYTE* const cSizePtr = (BYTE*)dst;
+    U32 cSize;
+    assert(compress != NULL);
+    cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+BHSize),
+                          (int)(srcSize), (int)(srcSize-1),
+                          level, cdict);
+
+    if (cSize == 0 || cSize >= srcSize) {
+        cSize = (U32)srcSize;
+        LZ4F_writeLE32(cSizePtr, cSize | LZ4F_BLOCKUNCOMPRESSED_FLAG);
+        memcpy(cSizePtr+BHSize, src, srcSize);
+    } else {
+        LZ4F_writeLE32(cSizePtr, cSize);
+    }
+    if (crcFlag) {
+        U32 const crc32 = XXH32(cSizePtr+BHSize, cSize, 0);  /* checksum of compressed data */
+        LZ4F_writeLE32(cSizePtr+BHSize+cSize, crc32);
+    }
+    return BHSize + cSize + ((U32)crcFlag)*BFSize;
+}
+
+
+static int LZ4F_compressBlock(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
+{
+    int const acceleration = (level < 0) ? -level + 1 : 1;
+    DEBUGLOG(5, "LZ4F_compressBlock (srcSize=%i)", srcSize);
+    LZ4F_initStream(ctx, cdict, level, LZ4F_blockIndependent);
+    if (cdict) {
+        return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration);
+    } else {
+        return LZ4_compress_fast_extState_fastReset(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 < 0) ? -level + 1 : 1;
+    (void)cdict; /* init once at beginning of frame */
+    DEBUGLOG(5, "LZ4F_compressBlock_continue (srcSize=%i)", srcSize);
+    return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration);
+}
+
+static int LZ4F_compressBlockHC(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
+{
+    LZ4F_initStream(ctx, cdict, level, LZ4F_blockIndependent);
+    if (cdict) {
+        return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
+    }
+    return LZ4_compress_HC_extStateHC_fastReset(ctx, src, dst, srcSize, dstCapacity, 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; (void)cdict; /* init once at beginning of frame */
+    return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
+}
+
+static int LZ4F_doNotCompressBlock(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
+{
+    (void)ctx; (void)src; (void)dst; (void)srcSize; (void)dstCapacity; (void)level; (void)cdict;
+    return 0;
+}
+
+static compressFunc_t LZ4F_selectCompression(LZ4F_blockMode_t blockMode, int level, LZ4F_blockCompression_t  compressMode)
+{
+    if (compressMode == LZ4B_UNCOMPRESSED) return LZ4F_doNotCompressBlock;
+    if (level < LZ4HC_CLEVEL_MIN) {
+        if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlock;
+        return LZ4F_compressBlock_continue;
+    }
+    if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlockHC;
+    return LZ4F_compressBlockHC_continue;
+}
+
+/* Save history (up to 64KB) into @tmpBuff */
+static int LZ4F_localSaveDict(LZ4F_cctx_t* cctxPtr)
+{
+    if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
+        return LZ4_saveDict ((LZ4_stream_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB);
+    return LZ4_saveDictHC ((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB);
+}
+
+typedef enum { notDone, fromTmpBuffer, fromSrcBuffer } LZ4F_lastBlockStatus;
+
+static const LZ4F_compressOptions_t k_cOptionsNull = { 0, { 0, 0, 0 } };
+
+
+ /*! LZ4F_compressUpdateImpl() :
+ *  LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
+ *  When successful, the function always entirely consumes @srcBuffer.
+ *  src data is either buffered or compressed into @dstBuffer.
+ *  If the block compression does not match the compression of the previous block, the old data is flushed
+ *  and operations continue with the new compression mode.
+ * @dstCapacity MUST be >= LZ4F_compressBound(srcSize, preferencesPtr) when block compression is turned on.
+ * @compressOptionsPtr is optional : provide NULL to mean "default".
+ * @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())
+ *  After an error, the state is left in a UB state, and must be re-initialized.
+ */
+static size_t LZ4F_compressUpdateImpl(LZ4F_cctx* cctxPtr,
+                     void* dstBuffer, size_t dstCapacity,
+                     const void* srcBuffer, size_t srcSize,
+                     const LZ4F_compressOptions_t* compressOptionsPtr,
+                     LZ4F_blockCompression_t blockCompression)
+  {
+    size_t const blockSize = cctxPtr->maxBlockSize;
+    const BYTE* srcPtr = (const BYTE*)srcBuffer;
+    const BYTE* const srcEnd = srcPtr + srcSize;
+    BYTE* const dstStart = (BYTE*)dstBuffer;
+    BYTE* dstPtr = dstStart;
+    LZ4F_lastBlockStatus lastBlockCompressed = notDone;
+    compressFunc_t const compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel, blockCompression);
+    size_t bytesWritten;
+    DEBUGLOG(4, "LZ4F_compressUpdate (srcSize=%zu)", srcSize);
+
+    RETURN_ERROR_IF(cctxPtr->cStage != 1, compressionState_uninitialized);   /* state must be initialized and waiting for next block */
+    if (dstCapacity < LZ4F_compressBound_internal(srcSize, &(cctxPtr->prefs), cctxPtr->tmpInSize))
+        RETURN_ERROR(dstMaxSize_tooSmall);
+
+    if (blockCompression == LZ4B_UNCOMPRESSED && dstCapacity < srcSize)
+        RETURN_ERROR(dstMaxSize_tooSmall);
+
+    /* flush currently written block, to continue with new block compression */
+    if (cctxPtr->blockCompression != blockCompression) {
+        bytesWritten = LZ4F_flush(cctxPtr, dstBuffer, dstCapacity, compressOptionsPtr);
+        dstPtr += bytesWritten;
+        cctxPtr->blockCompression = blockCompression;
+    }
+
+    if (compressOptionsPtr == NULL) compressOptionsPtr = &k_cOptionsNull;
+
+    /* complete tmp buffer */
+    if (cctxPtr->tmpInSize > 0) {   /* some data already within tmp buffer */
+        size_t const sizeToCopy = blockSize - cctxPtr->tmpInSize;
+        assert(blockSize > cctxPtr->tmpInSize);
+        if (sizeToCopy > srcSize) {
+            /* add src to tmpIn buffer */
+            memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, srcSize);
+            srcPtr = srcEnd;
+            cctxPtr->tmpInSize += srcSize;
+            /* still needs some CRC */
+        } else {
+            /* complete tmpIn block and then compress it */
+            lastBlockCompressed = fromTmpBuffer;
+            memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, sizeToCopy);
+            srcPtr += sizeToCopy;
+
+            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;
+    }   }
+
+    while ((size_t)(srcEnd - srcPtr) >= blockSize) {
+        /* compress full blocks */
+        lastBlockCompressed = fromSrcBuffer;
+        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)) {
+        /* autoFlush : remaining input (< blockSize) is compressed */
+        lastBlockCompressed = fromSrcBuffer;
+        dstPtr += LZ4F_makeBlock(dstPtr,
+                                 srcPtr, (size_t)(srcEnd - srcPtr),
+                                 compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
+                                 cctxPtr->cdict,
+                                 cctxPtr->prefs.frameInfo.blockChecksumFlag);
+        srcPtr = srcEnd;
+    }
+
+    /* preserve dictionary within @tmpBuff whenever necessary */
+    if ((cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) && (lastBlockCompressed==fromSrcBuffer)) {
+        /* linked blocks are only supported in compressed mode, see LZ4F_uncompressedUpdate */
+        assert(blockCompression == LZ4B_COMPRESSED);
+        if (compressOptionsPtr->stableSrc) {
+            cctxPtr->tmpIn = cctxPtr->tmpBuff;  /* src is stable : dictionary remains in src across invocations */
+        } else {
+            int const realDictSize = LZ4F_localSaveDict(cctxPtr);
+            assert(0 <= realDictSize && realDictSize <= 64 KB);
+            cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
+        }
+    }
+
+    /* keep tmpIn within limits */
+    if (!(cctxPtr->prefs.autoFlush)  /* no autoflush : there may be some data left within internal buffer */
+      && (cctxPtr->tmpIn + blockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize) )  /* not enough room to store next block */
+    {
+        /* only preserve 64KB within internal buffer. Ensures there is enough room for next block.
+         * note: this situation necessarily implies lastBlockCompressed==fromTmpBuffer */
+        int const realDictSize = LZ4F_localSaveDict(cctxPtr);
+        cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
+        assert((cctxPtr->tmpIn + blockSize) <= (cctxPtr->tmpBuff + cctxPtr->maxBufferSize));
+    }
+
+    /* some input data left, necessarily < blockSize */
+    if (srcPtr < srcEnd) {
+        /* fill tmp buffer */
+        size_t const sizeToCopy = (size_t)(srcEnd - srcPtr);
+        memcpy(cctxPtr->tmpIn, srcPtr, sizeToCopy);
+        cctxPtr->tmpInSize = sizeToCopy;
+    }
+
+    if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled)
+        (void)XXH32_update(&(cctxPtr->xxh), srcBuffer, srcSize);
+
+    cctxPtr->totalInSize += srcSize;
+    return (size_t)(dstPtr - dstStart);
+}
+
+/*! LZ4F_compressUpdate() :
+ *  LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
+ *  When successful, the function always entirely consumes @srcBuffer.
+ *  src data is either buffered or compressed into @dstBuffer.
+ *  If previously an uncompressed block was written, buffered data is flushed
+ *  before appending compressed data is continued.
+ * @dstCapacity MUST be >= LZ4F_compressBound(srcSize, preferencesPtr).
+ * @compressOptionsPtr is optional : provide NULL to mean "default".
+ * @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())
+ *  After an error, the state is left in a UB state, and must be re-initialized.
+ */
+size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
+                           void* dstBuffer, size_t dstCapacity,
+                     const void* srcBuffer, size_t srcSize,
+                     const LZ4F_compressOptions_t* compressOptionsPtr)
+{
+     return LZ4F_compressUpdateImpl(cctxPtr,
+                                   dstBuffer, dstCapacity,
+                                   srcBuffer, srcSize,
+                                   compressOptionsPtr, LZ4B_COMPRESSED);
+}
+
+/*! LZ4F_compressUpdate() :
+ *  LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
+ *  When successful, the function always entirely consumes @srcBuffer.
+ *  src data is either buffered or compressed into @dstBuffer.
+ *  If previously an uncompressed block was written, buffered data is flushed
+ *  before appending compressed data is continued.
+ *  This is only supported when LZ4F_blockIndependent is used
+ * @dstCapacity MUST be >= LZ4F_compressBound(srcSize, preferencesPtr).
+ * @compressOptionsPtr is optional : provide NULL to mean "default".
+ * @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())
+ *  After an error, the state is left in a UB state, and must be re-initialized.
+ */
+size_t LZ4F_uncompressedUpdate(LZ4F_cctx* cctxPtr,
+                               void* dstBuffer, size_t dstCapacity,
+                         const void* srcBuffer, size_t srcSize,
+                         const LZ4F_compressOptions_t* compressOptionsPtr) {
+    RETURN_ERROR_IF(cctxPtr->prefs.frameInfo.blockMode != LZ4F_blockIndependent, blockMode_invalid);
+    return LZ4F_compressUpdateImpl(cctxPtr,
+                                   dstBuffer, dstCapacity,
+                                   srcBuffer, srcSize,
+                                   compressOptionsPtr, LZ4B_UNCOMPRESSED);
+}
+
+
+/*! LZ4F_flush() :
+ *  When compressed data must be sent immediately, without waiting for a block to be filled,
+ *  invoke LZ4_flush(), which will immediately compress any remaining data stored within LZ4F_cctx.
+ *  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 LZ4F_cctx.
+ *  The function outputs an error code if it fails (can be tested using LZ4F_isError())
+ *  LZ4F_compressOptions_t* is optional. NULL is a valid argument.
+ */
+size_t LZ4F_flush(LZ4F_cctx* cctxPtr,
+                  void* dstBuffer, size_t dstCapacity,
+            const LZ4F_compressOptions_t* compressOptionsPtr)
+{
+    BYTE* const dstStart = (BYTE*)dstBuffer;
+    BYTE* dstPtr = dstStart;
+    compressFunc_t compress;
+
+    if (cctxPtr->tmpInSize == 0) return 0;   /* nothing to flush */
+    RETURN_ERROR_IF(cctxPtr->cStage != 1, compressionState_uninitialized);
+    RETURN_ERROR_IF(dstCapacity < (cctxPtr->tmpInSize + BHSize + BFSize), dstMaxSize_tooSmall);
+    (void)compressOptionsPtr;   /* not useful (yet) */
+
+    /* select compression function */
+    compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel, cctxPtr->blockCompression);
+
+    /* compress tmp buffer */
+    dstPtr += LZ4F_makeBlock(dstPtr,
+                             cctxPtr->tmpIn, cctxPtr->tmpInSize,
+                             compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
+                             cctxPtr->cdict,
+                             cctxPtr->prefs.frameInfo.blockChecksumFlag);
+    assert(((void)"flush overflows dstBuffer!", (size_t)(dstPtr - dstStart) <= dstCapacity));
+
+    if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked)
+        cctxPtr->tmpIn += cctxPtr->tmpInSize;
+    cctxPtr->tmpInSize = 0;
+
+    /* keep tmpIn within limits */
+    if ((cctxPtr->tmpIn + cctxPtr->maxBlockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize)) {  /* necessarily LZ4F_blockLinked */
+        int const realDictSize = LZ4F_localSaveDict(cctxPtr);
+        cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
+    }
+
+    return (size_t)(dstPtr - dstStart);
+}
+
+
+/*! 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 an (optional) checksum.
+ *  LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
+ * @return: the number of bytes written into dstBuffer (necessarily >= 4 (endMark size))
+ *       or an error code if it fails (can be tested using LZ4F_isError())
+ *  The context can then be used again to compress a new frame, starting with LZ4F_compressBegin().
+ */
+size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr,
+                        void* dstBuffer, size_t dstCapacity,
+                  const LZ4F_compressOptions_t* compressOptionsPtr)
+{
+    BYTE* const dstStart = (BYTE*)dstBuffer;
+    BYTE* dstPtr = dstStart;
+
+    size_t const flushSize = LZ4F_flush(cctxPtr, dstBuffer, dstCapacity, compressOptionsPtr);
+    DEBUGLOG(5,"LZ4F_compressEnd: dstCapacity=%u", (unsigned)dstCapacity);
+    FORWARD_IF_ERROR(flushSize);
+    dstPtr += flushSize;
+
+    assert(flushSize <= dstCapacity);
+    dstCapacity -= flushSize;
+
+    RETURN_ERROR_IF(dstCapacity < 4, dstMaxSize_tooSmall);
+    LZ4F_writeLE32(dstPtr, 0);
+    dstPtr += 4;   /* endMark */
+
+    if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled) {
+        U32 const xxh = XXH32_digest(&(cctxPtr->xxh));
+        RETURN_ERROR_IF(dstCapacity < 8, dstMaxSize_tooSmall);
+        DEBUGLOG(5,"Writing 32-bit content checksum");
+        LZ4F_writeLE32(dstPtr, xxh);
+        dstPtr+=4;   /* content Checksum */
+    }
+
+    cctxPtr->cStage = 0;   /* state is now re-usable (with identical preferences) */
+    cctxPtr->maxBufferSize = 0;  /* reuse HC context */
+
+    if (cctxPtr->prefs.frameInfo.contentSize) {
+        if (cctxPtr->prefs.frameInfo.contentSize != cctxPtr->totalInSize)
+            RETURN_ERROR(frameSize_wrong);
+    }
+
+    return (size_t)(dstPtr - dstStart);
+}
+
+
+/*-***************************************************
+*   Frame Decompression
+*****************************************************/
+
+typedef enum {
+    dstage_getFrameHeader=0, dstage_storeFrameHeader,
+    dstage_init,
+    dstage_getBlockHeader, dstage_storeBlockHeader,
+    dstage_copyDirect, dstage_getBlockChecksum,
+    dstage_getCBlock, dstage_storeCBlock,
+    dstage_flushOut,
+    dstage_getSuffix, dstage_storeSuffix,
+    dstage_getSFrameSize, dstage_storeSFrameSize,
+    dstage_skipSkippable
+} dStage_t;
+
+struct LZ4F_dctx_s {
+    LZ4F_CustomMem cmem;
+    LZ4F_frameInfo_t frameInfo;
+    U32    version;
+    dStage_t dStage;
+    U64    frameRemainingSize;
+    size_t maxBlockSize;
+    size_t maxBufferSize;
+    BYTE*  tmpIn;
+    size_t tmpInSize;
+    size_t tmpInTarget;
+    BYTE*  tmpOutBuffer;
+    const BYTE* dict;
+    size_t dictSize;
+    BYTE*  tmpOut;
+    size_t tmpOutSize;
+    size_t tmpOutStart;
+    XXH32_state_t xxh;
+    XXH32_state_t blockChecksum;
+    int    skipChecksum;
+    BYTE   header[LZ4F_HEADER_SIZE_MAX];
+};  /* typedef'd to LZ4F_dctx in lz4frame.h */
+
+
+LZ4F_dctx* LZ4F_createDecompressionContext_advanced(LZ4F_CustomMem customMem, unsigned version)
+{
+    LZ4F_dctx* const dctx = (LZ4F_dctx*)LZ4F_calloc(sizeof(LZ4F_dctx), customMem);
+    if (dctx == NULL) return NULL;
+
+    dctx->cmem = customMem;
+    dctx->version = version;
+    return dctx;
+}
+
+/*! 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.
+ */
+LZ4F_errorCode_t
+LZ4F_createDecompressionContext(LZ4F_dctx** LZ4F_decompressionContextPtr, unsigned versionNumber)
+{
+    assert(LZ4F_decompressionContextPtr != NULL);  /* violation of narrow contract */
+    RETURN_ERROR_IF(LZ4F_decompressionContextPtr == NULL, parameter_null);  /* in case it nonetheless happen in production */
+
+    *LZ4F_decompressionContextPtr = LZ4F_createDecompressionContext_advanced(LZ4F_defaultCMem, versionNumber);
+    if (*LZ4F_decompressionContextPtr == NULL) {  /* failed allocation */
+        RETURN_ERROR(allocation_failed);
+    }
+    return LZ4F_OK_NoError;
+}
+
+LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx)
+{
+    LZ4F_errorCode_t result = LZ4F_OK_NoError;
+    if (dctx != NULL) {   /* can accept NULL input, like free() */
+      result = (LZ4F_errorCode_t)dctx->dStage;
+      LZ4F_free(dctx->tmpIn, dctx->cmem);
+      LZ4F_free(dctx->tmpOutBuffer, dctx->cmem);
+      LZ4F_free(dctx, dctx->cmem);
+    }
+    return result;
+}
+
+
+/*==---   Streaming Decompression operations   ---==*/
+
+void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx)
+{
+    dctx->dStage = dstage_getFrameHeader;
+    dctx->dict = NULL;
+    dctx->dictSize = 0;
+    dctx->skipChecksum = 0;
+}
+
+
+/*! LZ4F_decodeHeader() :
+ *  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)
+{
+    unsigned blockMode, blockChecksumFlag, contentSizeFlag, contentChecksumFlag, dictIDFlag, blockSizeID;
+    size_t frameHeaderSize;
+    const BYTE* srcPtr = (const BYTE*)src;
+
+    DEBUGLOG(5, "LZ4F_decodeHeader");
+    /* need to decode header to get frameInfo */
+    RETURN_ERROR_IF(srcSize < minFHSize, frameHeader_incomplete);   /* minimal frame header size */
+    MEM_INIT(&(dctx->frameInfo), 0, sizeof(dctx->frameInfo));
+
+    /* special case : skippable frames */
+    if ((LZ4F_readLE32(srcPtr) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) {
+        dctx->frameInfo.frameType = LZ4F_skippableFrame;
+        if (src == (void*)(dctx->header)) {
+            dctx->tmpInSize = srcSize;
+            dctx->tmpInTarget = 8;
+            dctx->dStage = dstage_storeSFrameSize;
+            return srcSize;
+        } else {
+            dctx->dStage = dstage_getSFrameSize;
+            return 4;
+    }   }
+
+    /* control magic number */
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+    if (LZ4F_readLE32(srcPtr) != LZ4F_MAGICNUMBER) {
+        DEBUGLOG(4, "frame header error : unknown magic number");
+        RETURN_ERROR(frameType_unknown);
+    }
+#endif
+    dctx->frameInfo.frameType = LZ4F_frame;
+
+    /* Flags */
+    {   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_ERROR(reservedFlag_set); /* Reserved bit */
+        if (version != 1) RETURN_ERROR(headerVersion_wrong);       /* Version Number, only supported value */
+    }
+
+    /* Frame Header Size */
+    frameHeaderSize = minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0);
+
+    if (srcSize < frameHeaderSize) {
+        /* not enough input to fully decode frame header */
+        if (srcPtr != dctx->header)
+            memcpy(dctx->header, srcPtr, srcSize);
+        dctx->tmpInSize = srcSize;
+        dctx->tmpInTarget = frameHeaderSize;
+        dctx->dStage = dstage_storeFrameHeader;
+        return srcSize;
+    }
+
+    {   U32 const BD = srcPtr[5];
+        blockSizeID = (BD>>4) & _3BITS;
+        /* validate */
+        if (((BD>>7)&_1BIT) != 0) RETURN_ERROR(reservedFlag_set);   /* Reserved bit */
+        if (blockSizeID < 4) RETURN_ERROR(maxBlockSize_invalid);    /* 4-7 only supported values for the time being */
+        if (((BD>>0)&_4BITS) != 0) RETURN_ERROR(reservedFlag_set);  /* Reserved bits */
+    }
+
+    /* check header */
+    assert(frameHeaderSize > 5);
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+    {   BYTE const HC = LZ4F_headerChecksum(srcPtr+4, frameHeaderSize-5);
+        RETURN_ERROR_IF(HC != srcPtr[frameHeaderSize-1], headerChecksum_invalid);
+    }
+#endif
+
+    /* save */
+    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((LZ4F_blockSizeID_t)blockSizeID);
+    if (contentSizeFlag)
+        dctx->frameRemainingSize = dctx->frameInfo.contentSize = LZ4F_readLE64(srcPtr+6);
+    if (dictIDFlag)
+        dctx->frameInfo.dictID = LZ4F_readLE32(srcPtr + frameHeaderSize - 5);
+
+    dctx->dStage = dstage_init;
+
+    return frameHeaderSize;
+}
+
+
+/*! LZ4F_headerSize() :
+ * @return : size of frame header
+ *           or an error code, which can be tested using LZ4F_isError()
+ */
+size_t LZ4F_headerSize(const void* src, size_t srcSize)
+{
+    RETURN_ERROR_IF(src == NULL, srcPtr_wrong);
+
+    /* minimal srcSize to determine header size */
+    if (srcSize < LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH)
+        RETURN_ERROR(frameHeader_incomplete);
+
+    /* special case : skippable frames */
+    if ((LZ4F_readLE32(src) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START)
+        return 8;
+
+    /* control magic number */
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+    if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER)
+        RETURN_ERROR(frameType_unknown);
+#endif
+
+    /* Frame Header Size */
+    {   BYTE const FLG = ((const BYTE*)src)[4];
+        U32 const contentSizeFlag = (FLG>>3) & _1BIT;
+        U32 const dictIDFlag = FLG & _1BIT;
+        return minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0);
+    }
+}
+
+/*! LZ4F_getFrameInfo() :
+ *  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)
+{
+    LZ4F_STATIC_ASSERT(dstage_getFrameHeader < dstage_storeFrameHeader);
+    if (dctx->dStage > dstage_storeFrameHeader) {
+        /* frameInfo already decoded */
+        size_t o=0, i=0;
+        *srcSizePtr = 0;
+        *frameInfoPtr = dctx->frameInfo;
+        /* returns : recommended nb of bytes for LZ4F_decompress() */
+        return LZ4F_decompress(dctx, NULL, &o, NULL, &i, NULL);
+    } else {
+        if (dctx->dStage == dstage_storeFrameHeader) {
+            /* frame decoding already started, in the middle of header => automatic fail */
+            *srcSizePtr = 0;
+            RETURN_ERROR(frameDecoding_alreadyStarted);
+        } else {
+            size_t const hSize = LZ4F_headerSize(srcBuffer, *srcSizePtr);
+            if (LZ4F_isError(hSize)) { *srcSizePtr=0; return hSize; }
+            if (*srcSizePtr < hSize) {
+                *srcSizePtr=0;
+                RETURN_ERROR(frameHeader_incomplete);
+            }
+
+            {   size_t 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;
+    }   }   }
+}
+
+
+/* LZ4F_updateDict() :
+ * only used for LZ4F_blockLinked mode
+ * Condition : @dstPtr != NULL
+ */
+static void LZ4F_updateDict(LZ4F_dctx* dctx,
+                      const BYTE* dstPtr, size_t dstSize, const BYTE* dstBufferStart,
+                      unsigned withinTmp)
+{
+    assert(dstPtr != NULL);
+    if (dctx->dictSize==0) dctx->dict = (const BYTE*)dstPtr;  /* will lead to prefix mode */
+    assert(dctx->dict != NULL);
+
+    if (dctx->dict + dctx->dictSize == dstPtr) {  /* prefix mode, everything within dstBuffer */
+        dctx->dictSize += dstSize;
+        return;
+    }
+
+    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 = (size_t)(dstPtr - dstBufferStart) + dstSize;
+        return;
+    }
+
+    assert(dstSize < 64 KB);   /* if dstSize >= 64 KB, dictionary would be set into dstBuffer directly */
+
+    /* dstBuffer does not contain whole useful history (64 KB), so it must be saved within tmpOutBuffer */
+    assert(dctx->tmpOutBuffer != NULL);
+
+    if (withinTmp && (dctx->dict == dctx->tmpOutBuffer)) {   /* continue history within tmpOutBuffer */
+        /* withinTmp expectation : content of [dstPtr,dstSize] is same as [dict+dictSize,dstSize], so we just extend it */
+        assert(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 = (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;
+        if (copySize > preserveSize) copySize = preserveSize;
+
+        memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
+
+        dctx->dict = dctx->tmpOutBuffer;
+        dctx->dictSize = preserveSize + dctx->tmpOutStart + dstSize;
+        return;
+    }
+
+    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;
+            memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize);
+            dctx->dictSize = preserveSize;
+        }
+        memcpy(dctx->tmpOutBuffer + dctx->dictSize, dstPtr, dstSize);
+        dctx->dictSize += dstSize;
+        return;
+    }
+
+    /* join dict & dest into tmp */
+    {   size_t preserveSize = 64 KB - 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 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)
+{
+    LZ4F_decompressOptions_t optionsNull;
+    const BYTE* const srcStart = (const BYTE*)srcBuffer;
+    const BYTE* const srcEnd = srcStart + *srcSizePtr;
+    const BYTE* srcPtr = srcStart;
+    BYTE* const dstStart = (BYTE*)dstBuffer;
+    BYTE* const dstEnd = dstStart ? dstStart + *dstSizePtr : NULL;
+    BYTE* dstPtr = dstStart;
+    const BYTE* selectedIn = NULL;
+    unsigned doAnotherStage = 1;
+    size_t nextSrcSizeHint = 1;
+
+
+    DEBUGLOG(5, "LZ4F_decompress : %p,%u => %p,%u",
+            srcBuffer, (unsigned)*srcSizePtr, dstBuffer, (unsigned)*dstSizePtr);
+    if (dstBuffer == NULL) assert(*dstSizePtr == 0);
+    MEM_INIT(&optionsNull, 0, sizeof(optionsNull));
+    if (decompressOptionsPtr==NULL) decompressOptionsPtr = &optionsNull;
+    *srcSizePtr = 0;
+    *dstSizePtr = 0;
+    assert(dctx != NULL);
+    dctx->skipChecksum |= (decompressOptionsPtr->skipChecksums != 0); /* once set, disable for the remainder of the frame */
+
+    /* behaves as a state machine */
+
+    while (doAnotherStage) {
+
+        switch(dctx->dStage)
+        {
+
+        case dstage_getFrameHeader:
+            DEBUGLOG(6, "dstage_getFrameHeader");
+            if ((size_t)(srcEnd-srcPtr) >= maxFHSize) {  /* enough to decode - shortcut */
+                size_t const hSize = LZ4F_decodeHeader(dctx, srcPtr, (size_t)(srcEnd-srcPtr));  /* will update dStage appropriately */
+                FORWARD_IF_ERROR(hSize);
+                srcPtr += hSize;
+                break;
+            }
+            dctx->tmpInSize = 0;
+            if (srcEnd-srcPtr == 0) return minFHSize;   /* 0-size input */
+            dctx->tmpInTarget = minFHSize;   /* minimum size to decode header */
+            dctx->dStage = dstage_storeFrameHeader;
+            /* fall-through */
+
+        case dstage_storeFrameHeader:
+            DEBUGLOG(6, "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 (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;
+            }
+            FORWARD_IF_ERROR( LZ4F_decodeHeader(dctx, dctx->header, dctx->tmpInTarget) ); /* will update dStage appropriately */
+            break;
+
+        case dstage_init:
+            DEBUGLOG(6, "dstage_init");
+            if (dctx->frameInfo.contentChecksumFlag) (void)XXH32_reset(&(dctx->xxh), 0);
+            /* internal buffers allocation */
+            {   size_t const bufferNeeded = dctx->maxBlockSize
+                    + ((dctx->frameInfo.blockMode==LZ4F_blockLinked) ? 128 KB : 0);
+                if (bufferNeeded > dctx->maxBufferSize) {   /* tmp buffers too small */
+                    dctx->maxBufferSize = 0;   /* ensure allocation will be re-attempted on next entry*/
+                    LZ4F_free(dctx->tmpIn, dctx->cmem);
+                    dctx->tmpIn = (BYTE*)LZ4F_malloc(dctx->maxBlockSize + BFSize /* block checksum */, dctx->cmem);
+                    RETURN_ERROR_IF(dctx->tmpIn == NULL, allocation_failed);
+                    LZ4F_free(dctx->tmpOutBuffer, dctx->cmem);
+                    dctx->tmpOutBuffer= (BYTE*)LZ4F_malloc(bufferNeeded, dctx->cmem);
+                    RETURN_ERROR_IF(dctx->tmpOutBuffer== NULL, 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 */
+                dctx->tmpInSize = 0;
+                dctx->dStage = dstage_storeBlockHeader;
+            }
+
+            if (dctx->dStage == dstage_storeBlockHeader)   /* can be skipped */
+        case dstage_storeBlockHeader:
+            {   size_t const remainingInput = (size_t)(srcEnd - srcPtr);
+                size_t const wantedData = BHSize - dctx->tmpInSize;
+                size_t const sizeToCopy = MIN(wantedData, remainingInput);
+                memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
+                srcPtr += sizeToCopy;
+                dctx->tmpInSize += sizeToCopy;
+
+                if (dctx->tmpInSize < BHSize) {   /* not enough input for cBlockSize */
+                    nextSrcSizeHint = BHSize - dctx->tmpInSize;
+                    doAnotherStage  = 0;
+                    break;
+                }
+                selectedIn = dctx->tmpIn;
+            }   /* if (dctx->dStage == dstage_storeBlockHeader) */
+
+        /* decode block header */
+            {   U32 const blockHeader = LZ4F_readLE32(selectedIn);
+                size_t const nextCBlockSize = blockHeader & 0x7FFFFFFFU;
+                size_t const crcSize = dctx->frameInfo.blockChecksumFlag * BFSize;
+                if (blockHeader==0) {  /* frameEnd signal, no more block */
+                    DEBUGLOG(5, "end of frame");
+                    dctx->dStage = dstage_getSuffix;
+                    break;
+                }
+                if (nextCBlockSize > dctx->maxBlockSize) {
+                    RETURN_ERROR(maxBlockSize_invalid);
+                }
+                if (blockHeader & LZ4F_BLOCKUNCOMPRESSED_FLAG) {
+                    /* next block is uncompressed */
+                    dctx->tmpInTarget = nextCBlockSize;
+                    DEBUGLOG(5, "next block is uncompressed (size %u)", (U32)nextCBlockSize);
+                    if (dctx->frameInfo.blockChecksumFlag) {
+                        (void)XXH32_reset(&dctx->blockChecksum, 0);
+                    }
+                    dctx->dStage = dstage_copyDirect;
+                    break;
+                }
+                /* next block is a compressed block */
+                dctx->tmpInTarget = nextCBlockSize + crcSize;
+                dctx->dStage = dstage_getCBlock;
+                if (dstPtr==dstEnd || srcPtr==srcEnd) {
+                    nextSrcSizeHint = BHSize + nextCBlockSize + crcSize;
+                    doAnotherStage = 0;
+                }
+                break;
+            }
+
+        case dstage_copyDirect:   /* uncompressed block */
+            DEBUGLOG(6, "dstage_copyDirect");
+            {   size_t sizeToCopy;
+                if (dstPtr == NULL) {
+                    sizeToCopy = 0;
+                } else {
+                    size_t const minBuffSize = MIN((size_t)(srcEnd-srcPtr), (size_t)(dstEnd-dstPtr));
+                    sizeToCopy = MIN(dctx->tmpInTarget, minBuffSize);
+                    memcpy(dstPtr, srcPtr, sizeToCopy);
+                    if (!dctx->skipChecksum) {
+                        if (dctx->frameInfo.blockChecksumFlag) {
+                            (void)XXH32_update(&dctx->blockChecksum, srcPtr, sizeToCopy);
+                        }
+                        if (dctx->frameInfo.contentChecksumFlag)
+                            (void)XXH32_update(&dctx->xxh, srcPtr, sizeToCopy);
+                    }
+                    if (dctx->frameInfo.contentSize)
+                        dctx->frameRemainingSize -= sizeToCopy;
+
+                    /* history management (linked blocks only)*/
+                    if (dctx->frameInfo.blockMode == LZ4F_blockLinked) {
+                        LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 0);
+                }   }
+
+                srcPtr += sizeToCopy;
+                dstPtr += sizeToCopy;
+                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;
+                }
+                dctx->tmpInTarget -= sizeToCopy;  /* need to copy more */
+            }
+            nextSrcSizeHint = dctx->tmpInTarget +
+                            +(dctx->frameInfo.blockChecksumFlag ? BFSize : 0)
+                            + BHSize /* next header size */;
+            doAnotherStage = 0;
+            break;
+
+        /* check block checksum for recently transferred uncompressed block */
+        case dstage_getBlockChecksum:
+            DEBUGLOG(6, "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;
+                }
+                if (!dctx->skipChecksum) {
+                    U32 const readCRC = LZ4F_readLE32(crcSrc);
+                    U32 const calcCRC = XXH32_digest(&dctx->blockChecksum);
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+                    DEBUGLOG(6, "compare block checksum");
+                    if (readCRC != calcCRC) {
+                        DEBUGLOG(4, "incorrect block checksum: %08X != %08X",
+                                readCRC, calcCRC);
+                        RETURN_ERROR(blockChecksum_invalid);
+                    }
+#else
+                    (void)readCRC;
+                    (void)calcCRC;
+#endif
+            }   }
+            dctx->dStage = dstage_getBlockHeader;  /* new block */
+            break;
+
+        case dstage_getCBlock:
+            DEBUGLOG(6, "dstage_getCBlock");
+            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 += dctx->tmpInTarget;
+
+            if (0)  /* always jump over next block */
+        case dstage_storeCBlock:
+            {   size_t const wantedData = dctx->tmpInTarget - dctx->tmpInSize;
+                size_t const inputLeft = (size_t)(srcEnd-srcPtr);
+                size_t const sizeToCopy = MIN(wantedData, inputLeft);
+                memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
+                dctx->tmpInSize += sizeToCopy;
+                srcPtr += sizeToCopy;
+                if (dctx->tmpInSize < dctx->tmpInTarget) { /* need more input */
+                    nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize)
+                                    + (dctx->frameInfo.blockChecksumFlag ? BFSize : 0)
+                                    + BHSize /* next header size */;
+                    doAnotherStage = 0;
+                    break;
+                }
+                selectedIn = dctx->tmpIn;
+            }
+
+            /* At this stage, input is large enough to decode a block */
+
+            /* First, decode and control block checksum if it exists */
+            if (dctx->frameInfo.blockChecksumFlag) {
+                assert(dctx->tmpInTarget >= 4);
+                dctx->tmpInTarget -= 4;
+                assert(selectedIn != NULL);  /* selectedIn is defined at this stage (either srcPtr, or dctx->tmpIn) */
+                {   U32 const readBlockCrc = LZ4F_readLE32(selectedIn + dctx->tmpInTarget);
+                    U32 const calcBlockCrc = XXH32(selectedIn, dctx->tmpInTarget, 0);
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+                    RETURN_ERROR_IF(readBlockCrc != calcBlockCrc, blockChecksum_invalid);
+#else
+                    (void)readBlockCrc;
+                    (void)calcBlockCrc;
+#endif
+            }   }
+
+            /* decode directly into destination buffer if there is enough room */
+            if ( ((size_t)(dstEnd-dstPtr) >= dctx->maxBlockSize)
+                 /* unless the dictionary is stored in tmpOut:
+                  * in which case it's faster to decode within tmpOut
+                  * to benefit from prefix speedup */
+              && !(dctx->dict!= NULL && (const BYTE*)dctx->dict + dctx->dictSize == dctx->tmpOut) )
+            {
+                const char* dict = (const char*)dctx->dict;
+                size_t dictSize = dctx->dictSize;
+                int decodedSize;
+                assert(dstPtr != NULL);
+                if (dict && dictSize > 1 GB) {
+                    /* overflow control : dctx->dictSize is an int, avoid truncation / sign issues */
+                    dict += dictSize - 64 KB;
+                    dictSize = 64 KB;
+                }
+                decodedSize = LZ4_decompress_safe_usingDict(
+                        (const char*)selectedIn, (char*)dstPtr,
+                        (int)dctx->tmpInTarget, (int)dctx->maxBlockSize,
+                        dict, (int)dictSize);
+                RETURN_ERROR_IF(decodedSize < 0, decompressionFailed);
+                if ((dctx->frameInfo.contentChecksumFlag) && (!dctx->skipChecksum))
+                    XXH32_update(&(dctx->xxh), dstPtr, (size_t)decodedSize);
+                if (dctx->frameInfo.contentSize)
+                    dctx->frameRemainingSize -= (size_t)decodedSize;
+
+                /* dictionary management */
+                if (dctx->frameInfo.blockMode==LZ4F_blockLinked) {
+                    LZ4F_updateDict(dctx, dstPtr, (size_t)decodedSize, dstStart, 0);
+                }
+
+                dstPtr += decodedSize;
+                dctx->dStage = dstage_getBlockHeader;  /* end of block, let's get another one */
+                break;
+            }
+
+            /* not enough place into dst : decode into tmpOut */
+
+            /* manage dictionary */
+            if (dctx->frameInfo.blockMode == LZ4F_blockLinked) {
+                if (dctx->dict == dctx->tmpOutBuffer) {
+                    /* truncate dictionary to 64 KB if too big */
+                    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 tmpOut */
+                    size_t const reservedDictSpace = MIN(dctx->dictSize, 64 KB);
+                    dctx->tmpOut = dctx->tmpOutBuffer + reservedDictSpace;
+            }   }
+
+            /* Decode block into tmpOut */
+            {   const char* dict = (const char*)dctx->dict;
+                size_t dictSize = dctx->dictSize;
+                int decodedSize;
+                if (dict && dictSize > 1 GB) {
+                    /* the dictSize param is an int, avoid truncation / sign issues */
+                    dict += dictSize - 64 KB;
+                    dictSize = 64 KB;
+                }
+                decodedSize = LZ4_decompress_safe_usingDict(
+                        (const char*)selectedIn, (char*)dctx->tmpOut,
+                        (int)dctx->tmpInTarget, (int)dctx->maxBlockSize,
+                        dict, (int)dictSize);
+                RETURN_ERROR_IF(decodedSize < 0, decompressionFailed);
+                if (dctx->frameInfo.contentChecksumFlag && !dctx->skipChecksum)
+                    XXH32_update(&(dctx->xxh), dctx->tmpOut, (size_t)decodedSize);
+                if (dctx->frameInfo.contentSize)
+                    dctx->frameRemainingSize -= (size_t)decodedSize;
+                dctx->tmpOutSize = (size_t)decodedSize;
+                dctx->tmpOutStart = 0;
+                dctx->dStage = dstage_flushOut;
+            }
+            /* fall-through */
+
+        case dstage_flushOut:  /* flush decoded data from tmpOut to dstBuffer */
+            DEBUGLOG(6, "dstage_flushOut");
+            if (dstPtr != NULL) {
+                size_t const sizeToCopy = MIN(dctx->tmpOutSize - dctx->tmpOutStart, (size_t)(dstEnd-dstPtr));
+                memcpy(dstPtr, dctx->tmpOut + dctx->tmpOutStart, sizeToCopy);
+
+                /* dictionary management */
+                if (dctx->frameInfo.blockMode == LZ4F_blockLinked)
+                    LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 1 /*withinTmp*/);
+
+                dctx->tmpOutStart += sizeToCopy;
+                dstPtr += sizeToCopy;
+            }
+            if (dctx->tmpOutStart == dctx->tmpOutSize) { /* all flushed */
+                dctx->dStage = dstage_getBlockHeader;  /* get next block */
+                break;
+            }
+            /* could not flush everything : stop there, just request a block header */
+            doAnotherStage = 0;
+            nextSrcSizeHint = BHSize;
+            break;
+
+        case dstage_getSuffix:
+            RETURN_ERROR_IF(dctx->frameRemainingSize, frameSize_wrong);   /* incorrect frame size decoded */
+            if (!dctx->frameInfo.contentChecksumFlag) {  /* no checksum, frame is completed */
+                nextSrcSizeHint = 0;
+                LZ4F_resetDecompressionContext(dctx);
+                doAnotherStage = 0;
+                break;
+            }
+            if ((srcEnd - srcPtr) < 4) {  /* not enough size for entire CRC */
+                dctx->tmpInSize = 0;
+                dctx->dStage = dstage_storeSuffix;
+            } else {
+                selectedIn = srcPtr;
+                srcPtr += 4;
+            }
+
+            if (dctx->dStage == dstage_storeSuffix)   /* can be skipped */
+        case dstage_storeSuffix:
+            {   size_t const remainingInput = (size_t)(srcEnd - srcPtr);
+                size_t const wantedData = 4 - dctx->tmpInSize;
+                size_t const sizeToCopy = MIN(wantedData, remainingInput);
+                memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
+                srcPtr += sizeToCopy;
+                dctx->tmpInSize += sizeToCopy;
+                if (dctx->tmpInSize < 4) { /* not enough input to read complete suffix */
+                    nextSrcSizeHint = 4 - dctx->tmpInSize;
+                    doAnotherStage=0;
+                    break;
+                }
+                selectedIn = dctx->tmpIn;
+            }   /* if (dctx->dStage == dstage_storeSuffix) */
+
+        /* case dstage_checkSuffix: */   /* no direct entry, avoid initialization risks */
+            if (!dctx->skipChecksum) {
+                U32 const readCRC = LZ4F_readLE32(selectedIn);
+                U32 const resultCRC = XXH32_digest(&(dctx->xxh));
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+                RETURN_ERROR_IF(readCRC != resultCRC, contentChecksum_invalid);
+#else
+                (void)readCRC;
+                (void)resultCRC;
+#endif
+            }
+            nextSrcSizeHint = 0;
+            LZ4F_resetDecompressionContext(dctx);
+            doAnotherStage = 0;
+            break;
+
+        case dstage_getSFrameSize:
+            if ((srcEnd - srcPtr) >= 4) {
+                selectedIn = srcPtr;
+                srcPtr += 4;
+            } else {
+                /* not enough input to read cBlockSize field */
+                dctx->tmpInSize = 4;
+                dctx->tmpInTarget = 8;
+                dctx->dStage = dstage_storeSFrameSize;
+            }
+
+            if (dctx->dStage == dstage_storeSFrameSize)
+        case dstage_storeSFrameSize:
+            {   size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize,
+                                             (size_t)(srcEnd - srcPtr) );
+                memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
+                srcPtr += sizeToCopy;
+                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 = dctx->header + 4;
+            }   /* if (dctx->dStage == dstage_storeSFrameSize) */
+
+        /* case dstage_decodeSFrameSize: */   /* no direct entry */
+            {   size_t const SFrameSize = LZ4F_readLE32(selectedIn);
+                dctx->frameInfo.contentSize = SFrameSize;
+                dctx->tmpInTarget = SFrameSize;
+                dctx->dStage = dstage_skipSkippable;
+                break;
+            }
+
+        case dstage_skipSkippable:
+            {   size_t const skipSize = MIN(dctx->tmpInTarget, (size_t)(srcEnd-srcPtr));
+                srcPtr += skipSize;
+                dctx->tmpInTarget -= skipSize;
+                doAnotherStage = 0;
+                nextSrcSizeHint = dctx->tmpInTarget;
+                if (nextSrcSizeHint) break;  /* still more to skip */
+                /* frame fully skipped : prepare context for a new frame */
+                LZ4F_resetDecompressionContext(dctx);
+                break;
+            }
+        }   /* switch (dctx->dStage) */
+    }   /* while (doAnotherStage) */
+
+    /* preserve history within tmpOut whenever necessary */
+    LZ4F_STATIC_ASSERT((unsigned)dstage_init == 2);
+    if ( (dctx->frameInfo.blockMode==LZ4F_blockLinked)  /* next block will use up to 64KB from previous ones */
+      && (dctx->dict != dctx->tmpOutBuffer)             /* dictionary is not already within tmp */
+      && (dctx->dict != NULL)                           /* dictionary exists */
+      && (!decompressOptionsPtr->stableDst)             /* cannot rely on dst data to remain there for next call */
+      && ((unsigned)(dctx->dStage)-2 < (unsigned)(dstage_getSuffix)-2) )  /* valid stages : [init ... getSuffix[ */
+    {
+        if (dctx->dStage == dstage_flushOut) {
+            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;
+            if (copySize > preserveSize) copySize = preserveSize;
+            assert(dctx->tmpOutBuffer != NULL);
+
+            memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
+
+            dctx->dict = dctx->tmpOutBuffer;
+            dctx->dictSize = preserveSize + dctx->tmpOutStart;
+        } else {
+            const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize;
+            size_t const newDictSize = MIN(dctx->dictSize, 64 KB);
+
+            memcpy(dctx->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize);
+
+            dctx->dict = dctx->tmpOutBuffer;
+            dctx->dictSize = newDictSize;
+            dctx->tmpOut = dctx->tmpOutBuffer + newDictSize;
+        }
+    }
+
+    *srcSizePtr = (size_t)(srcPtr - srcStart);
+    *dstSizePtr = (size_t)(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);
+}