/var/lib/jenkins/workspace/firefox-scan-build/mfbt/lz4/lz4frame.c

Bug Summary

File:	var/lib/jenkins/workspace/firefox-scan-build/mfbt/lz4/lz4frame.c
Warning:	line 1579, column 9 Null pointer passed to 2nd parameter expecting 'nonnull'
Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name lz4frame.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -ffp-contract=off -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/mfbt -fcoverage-compilation-dir=/var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/mfbt -resource-dir /usr/lib/llvm-18/lib/clang/18 -include /var/lib/jenkins/workspace/firefox-scan-build/config/gcc_hidden.h -include /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/mozilla-config.h -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/system_wrappers -U _FORTIFY_SOURCE -D _FORTIFY_SOURCE=2 -D DEBUG=1 -D IMPL_MFBT -D LZ4LIB_VISIBILITY= -D MOZ_SUPPORT_LEAKCHECKING -I /var/lib/jenkins/workspace/firefox-scan-build/mfbt -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/mfbt -I /var/lib/jenkins/workspace/firefox-scan-build/mfbt/double-conversion -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/nspr -I /var/lib/jenkins/workspace/firefox-scan-build/obj-x86_64-pc-linux-gnu/dist/include/nss -D MOZILLA_CLIENT -internal-isystem /usr/lib/llvm-18/lib/clang/18/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-error=tautological-type-limit-compare -Wno-range-loop-analysis -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=free-nonheap-object -Wno-error=atomic-alignment -Wno-error=deprecated-builtins -Wno-psabi -Wno-error=builtin-macro-redefined -Wno-unknown-warning-option -std=gnu99 -ferror-limit 19 -stack-protector 2 -fstack-clash-protection -ftrivial-auto-var-init=pattern -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2024-07-27-022226-2793976-1 -x c /var/lib/jenkins/workspace/firefox-scan-build/mfbt/lz4/lz4frame.c
1/*
* 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
*/

35/* 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).
*/


44/*-************************************
45*  Compiler Options
46**************************************/
47#include <limits.h>
48#ifdef _MSC_VER    /* Visual Studio */
49#  pragma warning(disable : 4127)   /* disable: C4127: conditional expression is constant */
50#endif


53/*-************************************
54*  Tuning parameters
55**************************************/
56/*
* LZ4F_HEAPMODE :
* Control how LZ4F_compressFrame allocates the Compression State,
* either on stack (0:default, fastest), or in memory heap (1:requires malloc()).
*/
61#ifndef LZ4F_HEAPMODE0
62#  define LZ4F_HEAPMODE0 0
63#endif


66/*-************************************
67*  Library declarations
68**************************************/
69#define LZ4F_STATIC_LINKING_ONLY
70#include "lz4frame.h"
71#define LZ4_STATIC_LINKING_ONLY
72#include "lz4.h"
73#define LZ4_HC_STATIC_LINKING_ONLY
74#include "lz4hc.h"
75#define XXH_STATIC_LINKING_ONLY
76#include "xxhash.h"


79/*-************************************
80*  Memory routines
81**************************************/
82/*
* User may redirect invocations of
* malloc(), calloc() and free()
* towards another library or solution of their choice
* by modifying below section.
87**/

89#include <string.h>   /* memset, memcpy, memmove */
90#ifndef LZ4_SRC_INCLUDED  /* avoid redefinition when sources are coalesced */
91#  define MEM_INIT(p,v,s)memset((p),(v),(s))   memset((p),(v),(s))
92#endif

94#ifndef LZ4_SRC_INCLUDED   /* avoid redefinition when sources are coalesced */
95#  include <stdlib.h>   /* malloc, calloc, free */
96#  define ALLOC(s)malloc(s)          malloc(s)
97#  define ALLOC_AND_ZERO(s)calloc(1,(s)) calloc(1,(s))
98#  define FREEMEM(p)free(p)        free(p)
99#endif

101static void* LZ4F_calloc(size_t s, LZ4F_CustomMem cmem)
102{
  /* custom calloc defined : use it */
  if (cmem.customCalloc != NULL((void*)0)) {
      return cmem.customCalloc(cmem.opaqueState, s);
  }
  /* nothing defined : use default <stdlib.h>'s calloc() */
  if (cmem.customAlloc == NULL((void*)0)) {
      return ALLOC_AND_ZERO(s)calloc(1,(s));
  }
  /* only custom alloc defined : use it, and combine it with memset() */
  {   void* const p = cmem.customAlloc(cmem.opaqueState, s);
      if (p != NULL((void*)0)) MEM_INIT(p, 0, s)memset((p),(0),(s));
      return p;
115}   }

117static void* LZ4F_malloc(size_t s, LZ4F_CustomMem cmem)
118{
  /* custom malloc defined : use it */
  if (cmem.customAlloc != NULL((void*)0)) {
      return cmem.customAlloc(cmem.opaqueState, s);
  }
  /* nothing defined : use default <stdlib.h>'s malloc() */
  return ALLOC(s)malloc(s);
125}

127static void LZ4F_free(void* p, LZ4F_CustomMem cmem)
128{
  if (p == NULL((void*)0)) return;
  if (cmem.customFree != NULL((void*)0)) {
      /* custom allocation defined : use it */
      cmem.customFree(cmem.opaqueState, p);
      return;
  }
  /* nothing defined : use default <stdlib.h>'s free() */
  FREEMEM(p)free(p);
137}


140/*-************************************
141*  Debug
142**************************************/
143#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1)
144#  include <assert.h>
145#else
146#  ifndef assert
147#    define assert(condition)((void)0) ((void)0)
148#  endif
149#endif

151#define LZ4F_STATIC_ASSERT(c){ enum { LZ4F_static_assert = 1/(int)(!!(c)) }; }    { enum { LZ4F_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */

153#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2) && !defined(DEBUGLOG)
154#  include <stdio.h>
155static int g_debuglog_enable = 1;
156#  define DEBUGLOG(l, ...){} {                                  \
              if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) {  \
                  fprintf(stderr, __FILE__"/var/lib/jenkins/workspace/firefox-scan-build/mfbt/lz4/lz4frame.c" " (%i): ", __LINE__158 );  \
                  fprintf(stderr, __VA_ARGS__);             \
                  fprintf(stderr, " \n");                   \
          }   }
162#else
163#  define DEBUGLOG(l, ...){}      {}    /* disabled */
164#endif


167/*-************************************
168*  Basic Types
169**************************************/
170#if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__199901L) && (__STDC_VERSION__199901L >= 199901L) /* C99 */) )
171# include <stdint.h>
typedef  uint8_t BYTE;
typedef uint16_t U16;
typedef uint32_t U32;
typedef  int32_t S32;
typedef uint64_t U64;
177#else
typedef unsigned char       BYTE;
typedef unsigned short      U16;
typedef unsigned int        U32;
typedef   signed int        S32;
typedef unsigned long long  U64;
183#endif


186/* unoptimized version; solves endianness & alignment issues */
187static U32 LZ4F_readLE32 (const void* src)
188{
  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;
195}

197static void LZ4F_writeLE32 (void* dst, U32 value32)
198{
  BYTE* const dstPtr = (BYTE*)dst;
  dstPtr[0] = (BYTE)value32;
  dstPtr[1] = (BYTE)(value32 >> 8);
  dstPtr[2] = (BYTE)(value32 >> 16);
  dstPtr[3] = (BYTE)(value32 >> 24);
204}

206static U64 LZ4F_readLE64 (const void* src)
207{
  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;
218}

220static void LZ4F_writeLE64 (void* dst, U64 value64)
221{
  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);
231}


234/*-************************************
235*  Constants
236**************************************/
237#ifndef LZ4_SRC_INCLUDED   /* avoid double definition */
238#  define KB*(1<<10) *(1<<10)
239#  define MB*(1<<20) *(1<<20)
240#  define GB*(1<<30) *(1<<30)
241#endif

243#define _1BIT0x01  0x01
244#define _2BITS0x03 0x03
245#define _3BITS0x07 0x07
246#define _4BITS0x0F 0x0F
247#define _8BITS0xFF 0xFF

249#define LZ4F_BLOCKUNCOMPRESSED_FLAG0x80000000U 0x80000000U
250#define LZ4F_BLOCKSIZEID_DEFAULTLZ4F_max64KB LZ4F_max64KB

252static const size_t minFHSize = LZ4F_HEADER_SIZE_MIN7;   /*  7 */
253static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX19;   /* 19 */
254static const size_t BHSize = LZ4F_BLOCK_HEADER_SIZE4;  /* block header : size, and compress flag */
255static const size_t BFSize = LZ4F_BLOCK_CHECKSUM_SIZE4;  /* block footer : checksum (optional) */


258/*-************************************
259*  Structures and local types
260**************************************/

262typedef enum { LZ4B_COMPRESSED, LZ4B_UNCOMPRESSED} LZ4F_BlockCompressMode_e;
263typedef enum { ctxNone, ctxFast, ctxHC } LZ4F_CtxType_e;

265typedef struct LZ4F_cctx_s
266{
  LZ4F_CustomMem cmem;
  LZ4F_preferences_t prefs;
  U32    version;
  U32    cStage;     /* 0 : compression uninitialized ; 1 : initialized, can compress */
  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    lz4CtxType;  /* in use as: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
  LZ4F_BlockCompressMode_e  blockCompressMode;
283} LZ4F_cctx_t;


286/*-************************************
287*  Error management
288**************************************/
289#define LZ4F_GENERATE_STRING(STRING)"STRING", #STRING,
290static const char* LZ4F_errorStrings[] = { LZ4F_LIST_ERRORS(LZ4F_GENERATE_STRING)"OK_NoError", "ERROR_GENERIC", "ERROR_maxBlockSize_invalid", "ERROR_blockMode_invalid"
, "ERROR_parameter_invalid", "ERROR_compressionLevel_invalid"
, "ERROR_headerVersion_wrong", "ERROR_blockChecksum_invalid",
 "ERROR_reservedFlag_set", "ERROR_allocation_failed", "ERROR_srcSize_tooLarge"
, "ERROR_dstMaxSize_tooSmall", "ERROR_frameHeader_incomplete"
, "ERROR_frameType_unknown", "ERROR_frameSize_wrong", "ERROR_srcPtr_wrong"
, "ERROR_decompressionFailed", "ERROR_headerChecksum_invalid"
, "ERROR_contentChecksum_invalid", "ERROR_frameDecoding_alreadyStarted"
, "ERROR_compressionState_uninitialized", "ERROR_parameter_null"
, "ERROR_io_write", "ERROR_io_read", "ERROR_maxCode", };


293unsigned LZ4F_isError(LZ4F_errorCode_t code)
294{
  return (code > (LZ4F_errorCode_t)(-LZ4F_ERROR_maxCode));
296}

298const char* LZ4F_getErrorName(LZ4F_errorCode_t code)
299{
  static const char* codeError = "Unspecified error code";
  if (LZ4F_isError(code)) return LZ4F_errorStrings[-(int)(code)];
  return codeError;
303}

305LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult)
306{
  if (!LZ4F_isError(functionResult)) return LZ4F_OK_NoError;
  return (LZ4F_errorCodes)(-(ptrdiff_t)functionResult);
309}

311static LZ4F_errorCode_t LZ4F_returnErrorCode(LZ4F_errorCodes code)
312{
  /* A compilation error here means sizeof(ptrdiff_t) is not large enough */
  LZ4F_STATIC_ASSERT(sizeof(ptrdiff_t) >= sizeof(size_t)){ enum { LZ4F_static_assert = 1/(int)(!!(sizeof(ptrdiff_t) >=
 sizeof(size_t))) }; };
  return (LZ4F_errorCode_t)-(ptrdiff_t)code;
316}

318#define RETURN_ERROR(e)return LZ4F_returnErrorCode(LZ4F_ERROR_e) return LZ4F_returnErrorCode(LZ4F_ERROR_ ## e)

320#define RETURN_ERROR_IF(c,e)do { if (c) { {}; return LZ4F_returnErrorCode(LZ4F_ERROR_e); }
 } while (0) do {  \
      if (c) {                   \
          DEBUGLOG(3, "Error: " #c){}; \
          RETURN_ERROR(e)return LZ4F_returnErrorCode(LZ4F_ERROR_e);       \
      }                          \
  } while (0)

327#define FORWARD_IF_ERROR(r)do { if (LZ4F_isError(r)) return (r); } while (0) do { if (LZ4F_isError(r)) return (r); } while (0)

329unsigned LZ4F_getVersion(void) { return LZ4F_VERSION100; }

331int LZ4F_compressionLevel_max(void) { return LZ4HC_CLEVEL_MAX12; }

333size_t LZ4F_getBlockSize(LZ4F_blockSizeID_t blockSizeID)
334{
  static const size_t blockSizes[4] = { 64 KB*(1<<10), 256 KB*(1<<10), 1 MB*(1<<20), 4 MB*(1<<20) };

  if (blockSizeID == 0) blockSizeID = LZ4F_BLOCKSIZEID_DEFAULTLZ4F_max64KB;
  if (blockSizeID < LZ4F_max64KB || blockSizeID > LZ4F_max4MB)
      RETURN_ERROR(maxBlockSize_invalid)return LZ4F_returnErrorCode(LZ4F_ERROR_maxBlockSize_invalid);
  {   int const blockSizeIdx = (int)blockSizeID - (int)LZ4F_max64KB;
      return blockSizes[blockSizeIdx];
342}   }

344/*-************************************
345*  Private functions
346**************************************/
347#define MIN(a,b)( (a) < (b) ? (a) : (b) )   ( (a) < (b) ? (a) : (b) )

349static BYTE LZ4F_headerChecksum (const void* header, size_t length)
350{
  U32 const xxh = XXH32(header, length, 0);
  return (BYTE)(xxh >> 8);
353}


356/*-************************************
357*  Simple-pass compression functions
358**************************************/
359static LZ4F_blockSizeID_t LZ4F_optimalBSID(const LZ4F_blockSizeID_t requestedBSID,
                                         const size_t srcSize)
361{
  LZ4F_blockSizeID_t proposedBSID = LZ4F_max64KB;
  size_t maxBlockSize = 64 KB*(1<<10);
  while (requestedBSID > proposedBSID) {
      if (srcSize <= maxBlockSize)
          return proposedBSID;
      proposedBSID = (LZ4F_blockSizeID_t)((int)proposedBSID + 1);
      maxBlockSize <<= 2;
  }
  return requestedBSID;
371}

373/*! 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.
*/
379static size_t LZ4F_compressBound_internal(size_t srcSize,
                                  const LZ4F_preferences_t* preferencesPtr,
                                        size_t alreadyBuffered)
382{
  LZ4F_preferences_t prefsNull = LZ4F_INIT_PREFERENCES{ { LZ4F_max64KB, LZ4F_blockLinked, LZ4F_noContentChecksum, LZ4F_frame
, 0ULL, 0U, LZ4F_noBlockChecksum }, 0, 0u, 0u, { 0u, 0u, 0u }
 };
  prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled;   /* worst case */
  prefsNull.frameInfo.blockChecksumFlag = LZ4F_blockChecksumEnabled;   /* worst case */
  {   const LZ4F_preferences_t* const prefsPtr = (preferencesPtr==NULL((void*)0)) ? &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)( (alreadyBuffered) < (maxBuffered) ? (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;
  }
404}

406size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
407{
  LZ4F_preferences_t prefs;
  size_t const headerSize = maxFHSize;      /* max header size, including optional fields */

  if (preferencesPtr!=NULL((void*)0)) prefs = *preferencesPtr;
  else MEM_INIT(&prefs, 0, sizeof(prefs))memset((&prefs),(0),(sizeof(prefs)));
  prefs.autoFlush = 1;

  return headerSize + LZ4F_compressBound_internal(srcSize, &prefs, 0);;
416}


419/*! 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())
*/
428size_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)
433{
  LZ4F_preferences_t prefs;
  LZ4F_compressOptions_t options;
  BYTE* const dstStart = (BYTE*) dstBuffer;
  BYTE* dstPtr = dstStart;
  BYTE* const dstEnd = dstStart + dstCapacity;

  DEBUGLOG(4, "LZ4F_compressFrame_usingCDict (srcSize=%u)", (unsigned)srcSize){};
  if (preferencesPtr!=NULL((void*)0))
      prefs = *preferencesPtr;
  else
      MEM_INIT(&prefs, 0, sizeof(prefs))memset((&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))memset((&options),(0),(sizeof(options)));
  options.stableSrc = 1;

  RETURN_ERROR_IF(dstCapacity < LZ4F_compressFrameBound(srcSize, &prefs), dstMaxSize_tooSmall)do { if (dstCapacity < LZ4F_compressFrameBound(srcSize, &
prefs)) { {}; return LZ4F_returnErrorCode(LZ4F_ERROR_dstMaxSize_tooSmall
); } } while (0);

  { size_t const headerSize = LZ4F_compressBegin_usingCDict(cctx, dstBuffer, dstCapacity, cdict, &prefs);  /* write header */
    FORWARD_IF_ERROR(headerSize)do { if (LZ4F_isError(headerSize)) return (headerSize); } while
 (0);
    dstPtr += headerSize;   /* header size */ }

  assert(dstEnd >= dstPtr)((void)0);
  { size_t const cSize = LZ4F_compressUpdate(cctx, dstPtr, (size_t)(dstEnd-dstPtr), srcBuffer, srcSize, &options);
    FORWARD_IF_ERROR(cSize)do { if (LZ4F_isError(cSize)) return (cSize); } while (0);
    dstPtr += cSize; }

  assert(dstEnd >= dstPtr)((void)0);
  { size_t const tailSize = LZ4F_compressEnd(cctx, dstPtr, (size_t)(dstEnd-dstPtr), &options);   /* flush last block, and generate suffix */
    FORWARD_IF_ERROR(tailSize)do { if (LZ4F_isError(tailSize)) return (tailSize); } while (
0);
    dstPtr += tailSize; }

  assert(dstEnd >= dstStart)((void)0);
  return (size_t)(dstPtr - dstStart);
474}


477/*! 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())
*/
484size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity,
                  const void* srcBuffer, size_t srcSize,
                  const LZ4F_preferences_t* preferencesPtr)
487{
  size_t result;
489#if (LZ4F_HEAPMODE0)
  LZ4F_cctx_t* cctxPtr;
  result = LZ4F_createCompressionContext(&cctxPtr, LZ4F_VERSION100);
  FORWARD_IF_ERROR(result)do { if (LZ4F_isError(result)) return (result); } while (0);
493#else
  LZ4F_cctx_t cctx;
  LZ4_stream_t lz4ctx;
  LZ4F_cctx_t* const cctxPtr = &cctx;

  MEM_INIT(&cctx, 0, sizeof(cctx))memset((&cctx),(0),(sizeof(cctx)));
  cctx.version = LZ4F_VERSION100;
  cctx.maxBufferSize = 5 MB*(1<<20);   /* mess with real buffer size to prevent dynamic allocation; works only because autoflush==1 & stableSrc==1 */
  if ( preferencesPtr == NULL((void*)0)
    || preferencesPtr->compressionLevel < LZ4HC_CLEVEL_MIN2 ) {
      LZ4_initStream(&lz4ctx, sizeof(lz4ctx));
      cctxPtr->lz4CtxPtr = &lz4ctx;
      cctxPtr->lz4CtxAlloc = 1;
      cctxPtr->lz4CtxType = ctxFast;
  }
508#endif
  DEBUGLOG(4, "LZ4F_compressFrame"){};

  result = LZ4F_compressFrame_usingCDict(cctxPtr, dstBuffer, dstCapacity,
                                         srcBuffer, srcSize,
                                         NULL((void*)0), preferencesPtr);

515#if (LZ4F_HEAPMODE0)
  LZ4F_freeCompressionContext(cctxPtr);
517#else
  if ( preferencesPtr != NULL((void*)0)
    && preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN2 ) {
      LZ4F_free(cctxPtr->lz4CtxPtr, cctxPtr->cmem);
  }
522#endif
  return result;
524}


527/*-***************************************************
528*   Dictionary compression
529*****************************************************/

531struct LZ4F_CDict_s {
  LZ4F_CustomMem cmem;
  void* dictContent;
  LZ4_stream_t* fastCtx;
  LZ4_streamHC_t* HCCtx;
536}; /* typedef'd to LZ4F_CDict within lz4frame_static.h */

538LZ4F_CDict*
539LZ4F_createCDict_advanced(LZ4F_CustomMem cmem, const void* dictBuffer, size_t dictSize)
540{
  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((void*)0);
  cdict->cmem = cmem;
  if (dictSize > 64 KB*(1<<10)) {
      dictStart += dictSize - 64 KB*(1<<10);
      dictSize = 64 KB*(1<<10);
  }
  cdict->dictContent = LZ4F_malloc(dictSize, cmem);
  /* note: using @cmem to allocate => can't use default create */
  cdict->fastCtx = (LZ4_stream_t*)LZ4F_malloc(sizeof(LZ4_stream_t), cmem);
  cdict->HCCtx = (LZ4_streamHC_t*)LZ4F_malloc(sizeof(LZ4_streamHC_t), cmem);
  if (!cdict->dictContent || !cdict->fastCtx || !cdict->HCCtx) {
      LZ4F_freeCDict(cdict);
      return NULL((void*)0);
  }
  memcpy(cdict->dictContent, dictStart, dictSize);
  LZ4_initStream(cdict->fastCtx, sizeof(LZ4_stream_t));
  LZ4_loadDictSlow(cdict->fastCtx, (const char*)cdict->dictContent, (int)dictSize);
  LZ4_initStreamHC(cdict->HCCtx, sizeof(LZ4_streamHC_t));
  /* note: we don't know at this point which compression level is going to be used
   * as a consequence, HCCtx is created for the more common HC mode */
  LZ4_setCompressionLevel(cdict->HCCtx, LZ4HC_CLEVEL_DEFAULT9);
  LZ4_loadDictHC(cdict->HCCtx, (const char*)cdict->dictContent, (int)dictSize);
  return cdict;
567}

569/*! 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 */
575LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize)
576{
  DEBUGLOG(4, "LZ4F_createCDict"){};
  return LZ4F_createCDict_advanced(LZ4F_defaultCMem, dictBuffer, dictSize);
579}

581void LZ4F_freeCDict(LZ4F_CDict* cdict)
582{
  if (cdict==NULL((void*)0)) 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);
588}


591/*-*********************************
592*  Advanced compression functions
593***********************************/

595LZ4F_cctx*
596LZ4F_createCompressionContext_advanced(LZ4F_CustomMem customMem, unsigned version)
597{
  LZ4F_cctx* const cctxPtr =
      (LZ4F_cctx*)LZ4F_calloc(sizeof(LZ4F_cctx), customMem);
  if (cctxPtr==NULL((void*)0)) return NULL((void*)0);

  cctxPtr->cmem = customMem;
  cctxPtr->version = version;
  cctxPtr->cStage = 0;   /* Uninitialized. Next stage : init cctx */

  return cctxPtr;
607}

609/*! 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();
616**/
617LZ4F_errorCode_t
618LZ4F_createCompressionContext(LZ4F_cctx** LZ4F_compressionContextPtr, unsigned version)
619{
  assert(LZ4F_compressionContextPtr != NULL)((void)0); /* considered a violation of narrow contract */
  /* in case it nonetheless happen in production */
  RETURN_ERROR_IF(LZ4F_compressionContextPtr == NULL, parameter_null)do { if (LZ4F_compressionContextPtr == ((void*)0)) { {}; return
 LZ4F_returnErrorCode(LZ4F_ERROR_parameter_null); } } while (
0);

  *LZ4F_compressionContextPtr = LZ4F_createCompressionContext_advanced(LZ4F_defaultCMem, version);
  RETURN_ERROR_IF(*LZ4F_compressionContextPtr==NULL, allocation_failed)do { if (*LZ4F_compressionContextPtr==((void*)0)) { {}; return
 LZ4F_returnErrorCode(LZ4F_ERROR_allocation_failed); } } while
 (0);
  return LZ4F_OK_NoError;
627}

629LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctxPtr)
630{
  if (cctxPtr != NULL((void*)0)) {  /* 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;
637}


640/**
* 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).
*/
648static void LZ4F_initStream(void* ctx,
                          const LZ4F_CDict* cdict,
                          int level,
                          LZ4F_blockMode_t blockMode) {
  if (level < LZ4HC_CLEVEL_MIN2) {
      if (cdict || 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);
          if (cdict)
              LZ4_attach_dictionary((LZ4_stream_t*)ctx, cdict->fastCtx);
      }
      /* In these cases, 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
       * which tableType they need the context to be in.
       * Therefore, a reset here would be wasted work. */
  } else {
      LZ4_resetStreamHC_fast((LZ4_streamHC_t*)ctx, level);
      if (cdict)
          LZ4_attach_HC_dictionary((LZ4_streamHC_t*)ctx, cdict->HCCtx);
  }
674}

676static int ctxTypeID_to_size(int ctxTypeID) {
  switch(ctxTypeID) {
  case 1:
      return LZ4_sizeofState();
  case 2:
      return LZ4_sizeofStateHC();
  default:
      return 0;
  }
685}

687/* LZ4F_compressBegin_internal()
* Note: only accepts @cdict _or_ @dictBuffer as non NULL.
*/
690size_t LZ4F_compressBegin_internal(LZ4F_cctx* cctx,
                        void* dstBuffer, size_t dstCapacity,
                        const void* dictBuffer, size_t dictSize,
                        const LZ4F_CDict* cdict,
                        const LZ4F_preferences_t* preferencesPtr)
695{
  LZ4F_preferences_t const prefNull = LZ4F_INIT_PREFERENCES{ { LZ4F_max64KB, LZ4F_blockLinked, LZ4F_noContentChecksum, LZ4F_frame
, 0ULL, 0U, LZ4F_noBlockChecksum }, 0, 0u, 0u, { 0u, 0u, 0u }
 };
  BYTE* const dstStart = (BYTE*)dstBuffer;
  BYTE* dstPtr = dstStart;

  RETURN_ERROR_IF(dstCapacity < maxFHSize, dstMaxSize_tooSmall)do { if (dstCapacity < maxFHSize) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_dstMaxSize_tooSmall); } } while (0);
  if (preferencesPtr == NULL((void*)0)) preferencesPtr = &prefNull;
  cctx->prefs = *preferencesPtr;

  /* cctx Management */
  {   U16 const ctxTypeID = (cctx->prefs.compressionLevel < LZ4HC_CLEVEL_MIN2) ? 1 : 2;
      int requiredSize = ctxTypeID_to_size(ctxTypeID);
      int allocatedSize = ctxTypeID_to_size(cctx->lz4CtxAlloc);
      if (allocatedSize < requiredSize) {
          /* not enough space allocated */
          LZ4F_free(cctx->lz4CtxPtr, cctx->cmem);
          if (cctx->prefs.compressionLevel < LZ4HC_CLEVEL_MIN2) {
              /* must take ownership of memory allocation,
               * in order to respect custom allocator contract */
              cctx->lz4CtxPtr = LZ4F_malloc(sizeof(LZ4_stream_t), cctx->cmem);
              if (cctx->lz4CtxPtr)
                  LZ4_initStream(cctx->lz4CtxPtr, sizeof(LZ4_stream_t));
          } else {
              cctx->lz4CtxPtr = LZ4F_malloc(sizeof(LZ4_streamHC_t), cctx->cmem);
              if (cctx->lz4CtxPtr)
                  LZ4_initStreamHC(cctx->lz4CtxPtr, sizeof(LZ4_streamHC_t));
          }
          RETURN_ERROR_IF(cctx->lz4CtxPtr == NULL, allocation_failed)do { if (cctx->lz4CtxPtr == ((void*)0)) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_allocation_failed); } } while (0);
          cctx->lz4CtxAlloc = ctxTypeID;
          cctx->lz4CtxType = ctxTypeID;
      } else if (cctx->lz4CtxType != ctxTypeID) {
          /* otherwise, a sufficient buffer is already allocated,
           * but we need to reset it to the correct context type */
          if (cctx->prefs.compressionLevel < LZ4HC_CLEVEL_MIN2) {
              LZ4_initStream((LZ4_stream_t*)cctx->lz4CtxPtr, sizeof(LZ4_stream_t));
          } else {
              LZ4_initStreamHC((LZ4_streamHC_t*)cctx->lz4CtxPtr, sizeof(LZ4_streamHC_t));
              LZ4_setCompressionLevel((LZ4_streamHC_t*)cctx->lz4CtxPtr, cctx->prefs.compressionLevel);
          }
          cctx->lz4CtxType = ctxTypeID;
  }   }

  /* Buffer Management */
  if (cctx->prefs.frameInfo.blockSizeID == 0)
      cctx->prefs.frameInfo.blockSizeID = LZ4F_BLOCKSIZEID_DEFAULTLZ4F_max64KB;
  cctx->maxBlockSize = LZ4F_getBlockSize(cctx->prefs.frameInfo.blockSizeID);

  {   size_t const requiredBuffSize = preferencesPtr->autoFlush ?
              ((cctx->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 64 KB*(1<<10) : 0) :  /* only needs past data up to window size */
              cctx->maxBlockSize + ((cctx->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 128 KB*(1<<10) : 0);

      if (cctx->maxBufferSize < requiredBuffSize) {
          cctx->maxBufferSize = 0;
          LZ4F_free(cctx->tmpBuff, cctx->cmem);
          cctx->tmpBuff = (BYTE*)LZ4F_malloc(requiredBuffSize, cctx->cmem);
          RETURN_ERROR_IF(cctx->tmpBuff == NULL, allocation_failed)do { if (cctx->tmpBuff == ((void*)0)) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_allocation_failed); } } while (0);
          cctx->maxBufferSize = requiredBuffSize;
  }   }
  cctx->tmpIn = cctx->tmpBuff;
  cctx->tmpInSize = 0;
  (void)XXH32_reset(&(cctx->xxh), 0);

  /* context init */
  cctx->cdict = cdict;
  if (cctx->prefs.frameInfo.blockMode == LZ4F_blockLinked) {
      /* frame init only for blockLinked : blockIndependent will be init at each block */
      LZ4F_initStream(cctx->lz4CtxPtr, cdict, cctx->prefs.compressionLevel, LZ4F_blockLinked);
  }
  if (preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN2) {
      LZ4_favorDecompressionSpeed((LZ4_streamHC_t*)cctx->lz4CtxPtr, (int)preferencesPtr->favorDecSpeed);
  }
  if (dictBuffer) {
      assert(cdict == NULL)((void)0);
      RETURN_ERROR_IF(dictSize > INT_MAX, parameter_invalid)do { if (dictSize > 2147483647) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_parameter_invalid); } } while (0);
      if (cctx->lz4CtxType == ctxFast) {
          /* lz4 fast*/
          LZ4_loadDict((LZ4_stream_t*)cctx->lz4CtxPtr, (const char*)dictBuffer, (int)dictSize);
      } else {
          /* lz4hc */
          assert(cctx->lz4CtxType == ctxHC)((void)0);
          LZ4_loadDictHC((LZ4_streamHC_t*)cctx->lz4CtxPtr, (const char*)dictBuffer, (int)dictSize);
      }
  }

  /* Stage 2 : Write Frame Header */

  /* Magic Number */
  LZ4F_writeLE32(dstPtr, LZ4F_MAGICNUMBER0x184D2204U);
  dstPtr += 4;
  {   BYTE* const headerStart = dstPtr;

      /* FLG Byte */
      *dstPtr++ = (BYTE)(((1 & _2BITS0x03) << 6)    /* Version('01') */
          + ((cctx->prefs.frameInfo.blockMode & _1BIT0x01 ) << 5)
          + ((cctx->prefs.frameInfo.blockChecksumFlag & _1BIT0x01 ) << 4)
          + ((unsigned)(cctx->prefs.frameInfo.contentSize > 0) << 3)
          + ((cctx->prefs.frameInfo.contentChecksumFlag & _1BIT0x01 ) << 2)
          +  (cctx->prefs.frameInfo.dictID > 0) );
      /* BD Byte */
      *dstPtr++ = (BYTE)((cctx->prefs.frameInfo.blockSizeID & _3BITS0x07) << 4);
      /* Optional Frame content size field */
      if (cctx->prefs.frameInfo.contentSize) {
          LZ4F_writeLE64(dstPtr, cctx->prefs.frameInfo.contentSize);
          dstPtr += 8;
          cctx->totalInSize = 0;
      }
      /* Optional dictionary ID field */
      if (cctx->prefs.frameInfo.dictID) {
          LZ4F_writeLE32(dstPtr, cctx->prefs.frameInfo.dictID);
          dstPtr += 4;
      }
      /* Header CRC Byte */
      *dstPtr = LZ4F_headerChecksum(headerStart, (size_t)(dstPtr - headerStart));
      dstPtr++;
  }

  cctx->cStage = 1;   /* header written, now request input data block */
  return (size_t)(dstPtr - dstStart);
813}

815size_t LZ4F_compressBegin(LZ4F_cctx* cctx,
                        void* dstBuffer, size_t dstCapacity,
                        const LZ4F_preferences_t* preferencesPtr)
818{
  return LZ4F_compressBegin_internal(cctx, dstBuffer, dstCapacity,
                                      NULL((void*)0), 0,
                                      NULL((void*)0), preferencesPtr);
822}

824/* LZ4F_compressBegin_usingDictOnce:
* Hidden implementation,
* employed for multi-threaded compression
* when frame defines linked blocks */
828size_t LZ4F_compressBegin_usingDictOnce(LZ4F_cctx* cctx,
                        void* dstBuffer, size_t dstCapacity,
                        const void* dict, size_t dictSize,
                        const LZ4F_preferences_t* preferencesPtr)
832{
  return LZ4F_compressBegin_internal(cctx, dstBuffer, dstCapacity,
                                      dict, dictSize,
                                      NULL((void*)0), preferencesPtr);
836}

838size_t LZ4F_compressBegin_usingDict(LZ4F_cctx* cctx,
                        void* dstBuffer, size_t dstCapacity,
                        const void* dict, size_t dictSize,
                        const LZ4F_preferences_t* preferencesPtr)
842{
  /* note : incorrect implementation :
   * this will only use the dictionary once,
   * instead of once *per* block when frames defines independent blocks */
  return LZ4F_compressBegin_usingDictOnce(cctx, dstBuffer, dstCapacity,
                                      dict, dictSize,
                                      preferencesPtr);
849}

851size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctx,
                        void* dstBuffer, size_t dstCapacity,
                        const LZ4F_CDict* cdict,
                        const LZ4F_preferences_t* preferencesPtr)
855{
  return LZ4F_compressBegin_internal(cctx, dstBuffer, dstCapacity,
                                      NULL((void*)0), 0,
                                     cdict, preferencesPtr);
859}


862/*  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.
*/
867size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
868{
  if (preferencesPtr && preferencesPtr->autoFlush) {
      return LZ4F_compressBound_internal(srcSize, preferencesPtr, 0);
  }
  return LZ4F_compressBound_internal(srcSize, preferencesPtr, (size_t)-1);
873}


876typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level, const LZ4F_CDict* cdict);


879/*! LZ4F_makeBlock():
*  compress a single block, add header and optional checksum.
*  assumption : dst buffer capacity is >= BHSize + srcSize + crcSize
*/
883static 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)
888{
  BYTE* const cSizePtr = (BYTE*)dst;
  U32 cSize;
  assert(compress != NULL)((void)0);
  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_FLAG0x80000000U);
      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;
908}


911static int LZ4F_compressBlock(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
912{
  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);
  }
921}

923static int LZ4F_compressBlock_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
924{
  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);
929}

931static int LZ4F_compressBlockHC(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
932{
  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);
938}

940static int LZ4F_compressBlockHC_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
941{
  (void)level; (void)cdict; /* init once at beginning of frame */
  return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
944}

946static int LZ4F_doNotCompressBlock(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
947{
  (void)ctx; (void)src; (void)dst; (void)srcSize; (void)dstCapacity; (void)level; (void)cdict;
  return 0;
950}

952static compressFunc_t LZ4F_selectCompression(LZ4F_blockMode_t blockMode, int level, LZ4F_BlockCompressMode_e  compressMode)
953{
  if (compressMode == LZ4B_UNCOMPRESSED)
      return LZ4F_doNotCompressBlock;
  if (level < LZ4HC_CLEVEL_MIN2) {
      if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlock;
      return LZ4F_compressBlock_continue;
  }
  if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlockHC;
  return LZ4F_compressBlockHC_continue;
962}

964/* Save history (up to 64KB) into @tmpBuff */
965static int LZ4F_localSaveDict(LZ4F_cctx_t* cctxPtr)
966{
  if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN2)
      return LZ4_saveDict ((LZ4_stream_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB*(1<<10));
  return LZ4_saveDictHC ((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB*(1<<10));
970}

972typedef enum { notDone, fromTmpBuffer, fromSrcBuffer } LZ4F_lastBlockStatus;

974static 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.
*/
989static size_t LZ4F_compressUpdateImpl(LZ4F_cctx* cctxPtr,
                   void* dstBuffer, size_t dstCapacity,
                   const void* srcBuffer, size_t srcSize,
                   const LZ4F_compressOptions_t* compressOptionsPtr,
                   LZ4F_BlockCompressMode_e 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)do { if (cctxPtr->cStage != 1) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_compressionState_uninitialized); } } while (0);   /* state must be initialized and waiting for next block */
  if (dstCapacity < LZ4F_compressBound_internal(srcSize, &(cctxPtr->prefs), cctxPtr->tmpInSize))
      RETURN_ERROR(dstMaxSize_tooSmall)return LZ4F_returnErrorCode(LZ4F_ERROR_dstMaxSize_tooSmall);

  if (blockCompression == LZ4B_UNCOMPRESSED && dstCapacity < srcSize)
      RETURN_ERROR(dstMaxSize_tooSmall)return LZ4F_returnErrorCode(LZ4F_ERROR_dstMaxSize_tooSmall);

  /* flush currently written block, to continue with new block compression */
  if (cctxPtr->blockCompressMode != blockCompression) {
      bytesWritten = LZ4F_flush(cctxPtr, dstBuffer, dstCapacity, compressOptionsPtr);
      dstPtr += bytesWritten;
      cctxPtr->blockCompressMode = blockCompression;
  }

  if (compressOptionsPtr == NULL((void*)0)) 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)((void)0);
      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)((void)0);
      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)((void)0);
          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))((void)0);
  }

  /* 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);
1105}

1107/*! 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.
*/
1119size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
                         void* dstBuffer, size_t dstCapacity,
                   const void* srcBuffer, size_t srcSize,
                   const LZ4F_compressOptions_t* compressOptionsPtr)
1123{
   return LZ4F_compressUpdateImpl(cctxPtr,
                                 dstBuffer, dstCapacity,
                                 srcBuffer, srcSize,
                                 compressOptionsPtr, LZ4B_COMPRESSED);
1128}

1130/*! LZ4F_uncompressedUpdate() :
*  Same as LZ4F_compressUpdate(), but requests blocks to be sent uncompressed.
*  This symbol 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.
*/
1139size_t LZ4F_uncompressedUpdate(LZ4F_cctx* cctxPtr,
                             void* dstBuffer, size_t dstCapacity,
                       const void* srcBuffer, size_t srcSize,
                       const LZ4F_compressOptions_t* compressOptionsPtr)
1143{
  return LZ4F_compressUpdateImpl(cctxPtr,
                                 dstBuffer, dstCapacity,
                                 srcBuffer, srcSize,
                                 compressOptionsPtr, LZ4B_UNCOMPRESSED);
1148}


1151/*! 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.
*/
1159size_t LZ4F_flush(LZ4F_cctx* cctxPtr,
                void* dstBuffer, size_t dstCapacity,
          const LZ4F_compressOptions_t* compressOptionsPtr)
1162{
  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)do { if (cctxPtr->cStage != 1) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_compressionState_uninitialized); } } while (0);
  RETURN_ERROR_IF(dstCapacity < (cctxPtr->tmpInSize + BHSize + BFSize), dstMaxSize_tooSmall)do { if (dstCapacity < (cctxPtr->tmpInSize + BHSize + BFSize
)) { {}; return LZ4F_returnErrorCode(LZ4F_ERROR_dstMaxSize_tooSmall
); } } while (0);
  (void)compressOptionsPtr;   /* not useful (yet) */

  /* select compression function */
  compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel, cctxPtr->blockCompressMode);

  /* 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))((void)0);

  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);
1194}


1197/*! 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().
*/
1206size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr,
                      void* dstBuffer, size_t dstCapacity,
                const LZ4F_compressOptions_t* compressOptionsPtr)
1209{
  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)do { if (LZ4F_isError(flushSize)) return (flushSize); } while
 (0);
  dstPtr += flushSize;

  assert(flushSize <= dstCapacity)((void)0);
  dstCapacity -= flushSize;

  RETURN_ERROR_IF(dstCapacity < 4, dstMaxSize_tooSmall)do { if (dstCapacity < 4) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_dstMaxSize_tooSmall); } } while (0);
  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)do { if (dstCapacity < 8) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_dstMaxSize_tooSmall); } } while (0);
      DEBUGLOG(5,"Writing 32-bit content checksum (0x%0X)", xxh){};
      LZ4F_writeLE32(dstPtr, xxh);
      dstPtr+=4;   /* content Checksum */
  }

  cctxPtr->cStage = 0;   /* state is now re-usable (with identical preferences) */

  if (cctxPtr->prefs.frameInfo.contentSize) {
      if (cctxPtr->prefs.frameInfo.contentSize != cctxPtr->totalInSize)
          RETURN_ERROR(frameSize_wrong)return LZ4F_returnErrorCode(LZ4F_ERROR_frameSize_wrong);
  }

  return (size_t)(dstPtr - dstStart);
1241}


1244/*-***************************************************
1245*   Frame Decompression
1246*****************************************************/

1248typedef 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
1258} dStage_t;

1260struct 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_MAX19];
1281};  /* typedef'd to LZ4F_dctx in lz4frame.h */


1284LZ4F_dctx* LZ4F_createDecompressionContext_advanced(LZ4F_CustomMem customMem, unsigned version)
1285{
  LZ4F_dctx* const dctx = (LZ4F_dctx*)LZ4F_calloc(sizeof(LZ4F_dctx), customMem);
  if (dctx == NULL((void*)0)) return NULL((void*)0);

  dctx->cmem = customMem;
  dctx->version = version;
  return dctx;
1292}

1294/*! 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.
*/
1300LZ4F_errorCode_t
1301LZ4F_createDecompressionContext(LZ4F_dctx** LZ4F_decompressionContextPtr, unsigned versionNumber)
1302{
  assert(LZ4F_decompressionContextPtr != NULL)((void)0);  /* violation of narrow contract */
  RETURN_ERROR_IF(LZ4F_decompressionContextPtr == NULL, parameter_null)do { if (LZ4F_decompressionContextPtr == ((void*)0)) { {}; return
 LZ4F_returnErrorCode(LZ4F_ERROR_parameter_null); } } while (
0);  /* in case it nonetheless happen in production */

  *LZ4F_decompressionContextPtr = LZ4F_createDecompressionContext_advanced(LZ4F_defaultCMem, versionNumber);
  if (*LZ4F_decompressionContextPtr == NULL((void*)0)) {  /* failed allocation */
      RETURN_ERROR(allocation_failed)return LZ4F_returnErrorCode(LZ4F_ERROR_allocation_failed);
  }
  return LZ4F_OK_NoError;
1311}

1313LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx)
1314{
  LZ4F_errorCode_t result = LZ4F_OK_NoError;
  if (dctx != NULL((void*)0)) {   /* 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;
1323}


1326/*==---   Streaming Decompression operations   ---==*/
1327void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx)
1328{
  DEBUGLOG(5, "LZ4F_resetDecompressionContext"){};
  dctx->dStage = dstage_getFrameHeader;
  dctx->dict = NULL((void*)0);
  dctx->dictSize = 0;
  dctx->skipChecksum = 0;
  dctx->frameRemainingSize = 0;
1335}


1338/*! 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())
*/
1346static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize)
1347{
  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)do { if (srcSize < minFHSize) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_frameHeader_incomplete); } } while (0);   /* minimal frame header size */
  MEM_INIT(&(dctx->frameInfo), 0, sizeof(dctx->frameInfo))memset((&(dctx->frameInfo)),(0),(sizeof(dctx->frameInfo
)));

  /* special case : skippable frames */
  if ((LZ4F_readLE32(srcPtr) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START0x184D2A50U) {
      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 */
1371#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
  if (LZ4F_readLE32(srcPtr) != LZ4F_MAGICNUMBER0x184D2204U) {
      DEBUGLOG(4, "frame header error : unknown magic number"){};
      RETURN_ERROR(frameType_unknown)return LZ4F_returnErrorCode(LZ4F_ERROR_frameType_unknown);
  }
1376#endif
  dctx->frameInfo.frameType = LZ4F_frame;

  /* Flags */
  {   U32 const FLG = srcPtr[4];
      U32 const version = (FLG>>6) & _2BITS0x03;
      blockChecksumFlag = (FLG>>4) & _1BIT0x01;
      blockMode = (FLG>>5) & _1BIT0x01;
      contentSizeFlag = (FLG>>3) & _1BIT0x01;
      contentChecksumFlag = (FLG>>2) & _1BIT0x01;
      dictIDFlag = FLG & _1BIT0x01;
      /* validate */
      if (((FLG>>1)&_1BIT0x01) != 0) RETURN_ERROR(reservedFlag_set)return LZ4F_returnErrorCode(LZ4F_ERROR_reservedFlag_set); /* Reserved bit */
      if (version != 1) RETURN_ERROR(headerVersion_wrong)return LZ4F_returnErrorCode(LZ4F_ERROR_headerVersion_wrong);       /* Version Number, only supported value */
  }
  DEBUGLOG(6, "contentSizeFlag: %u", contentSizeFlag){};

  /* 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) & _3BITS0x07;
      /* validate */
      if (((BD>>7)&_1BIT0x01) != 0) RETURN_ERROR(reservedFlag_set)return LZ4F_returnErrorCode(LZ4F_ERROR_reservedFlag_set);   /* Reserved bit */
      if (blockSizeID < 4) RETURN_ERROR(maxBlockSize_invalid)return LZ4F_returnErrorCode(LZ4F_ERROR_maxBlockSize_invalid);    /* 4-7 only supported values for the time being */
      if (((BD>>0)&_4BITS0x0F) != 0) RETURN_ERROR(reservedFlag_set)return LZ4F_returnErrorCode(LZ4F_ERROR_reservedFlag_set);  /* Reserved bits */
  }

  /* check header */
  assert(frameHeaderSize > 5)((void)0);
1416#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)do { if (HC != srcPtr[frameHeaderSize-1]) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_headerChecksum_invalid); } } while (0);
  }
1420#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;
1437}


1440/*! LZ4F_headerSize() :
* @return : size of frame header
*           or an error code, which can be tested using LZ4F_isError()
*/
1444size_t LZ4F_headerSize(const void* src, size_t srcSize)
1445{
  RETURN_ERROR_IF(src == NULL, srcPtr_wrong)do { if (src == ((void*)0)) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_srcPtr_wrong); } } while (0);

  /* minimal srcSize to determine header size */
  if (srcSize < LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH5)
      RETURN_ERROR(frameHeader_incomplete)return LZ4F_returnErrorCode(LZ4F_ERROR_frameHeader_incomplete
);

  /* special case : skippable frames */
  if ((LZ4F_readLE32(src) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START0x184D2A50U)
      return 8;

  /* control magic number */
1457#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
  if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER0x184D2204U)
      RETURN_ERROR(frameType_unknown)return LZ4F_returnErrorCode(LZ4F_ERROR_frameType_unknown);
1460#endif

  /* Frame Header Size */
  {   BYTE const FLG = ((const BYTE*)src)[4];
      U32 const contentSizeFlag = (FLG>>3) & _1BIT0x01;
      U32 const dictIDFlag = FLG & _1BIT0x01;
      return minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0);
  }
1468}

1470/*! 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.
*/
1485LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx,
                                 LZ4F_frameInfo_t* frameInfoPtr,
                           const void* srcBuffer, size_t* srcSizePtr)
1488{
  LZ4F_STATIC_ASSERT(dstage_getFrameHeader < dstage_storeFrameHeader){ enum { LZ4F_static_assert = 1/(int)(!!(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((void*)0), &o, NULL((void*)0), &i, NULL((void*)0));
  } else {
      if (dctx->dStage == dstage_storeFrameHeader) {
          /* frame decoding already started, in the middle of header => automatic fail */
          *srcSizePtr = 0;
          RETURN_ERROR(frameDecoding_alreadyStarted)return LZ4F_returnErrorCode(LZ4F_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)return LZ4F_returnErrorCode(LZ4F_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;
  }   }   }
1520}


1523/* LZ4F_updateDict() :
* only used for LZ4F_blockLinked mode
* Condition : @dstPtr != NULL
*/
1527static void LZ4F_updateDict(LZ4F_dctx* dctx,
                    const BYTE* dstPtr, size_t dstSize, const BYTE* dstBufferStart,
                    unsigned withinTmp)
1530{
  assert(dstPtr != NULL)((void)0);
  if (dctx->dictSize==0) dctx->dict = (const BYTE*)dstPtr;  /* will lead to prefix mode */
32
←
Assuming field 'dictSize' is not equal to 0→
33
←
Taking false branch→
  assert(dctx->dict != NULL)((void)0);

  if (dctx->dict + dctx->dictSize == dstPtr) {  /* prefix mode, everything within dstBuffer */
34
←
Taking false branch→
      dctx->dictSize += dstSize;
      return;
  }

  assert(dstPtr >= dstBufferStart)((void)0);
  if ((size_t)(dstPtr - dstBufferStart) + dstSize >= 64 KB*(1<<10)) {  /* history in dstBuffer becomes large enough to become dictionary */
35
←
Assuming the condition is false→
36
←
Taking false branch→
      dctx->dict = (const BYTE*)dstBufferStart;
      dctx->dictSize = (size_t)(dstPtr - dstBufferStart) + dstSize;
      return;
  }

  assert(dstSize < 64 KB)((void)0);   /* 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)((void)0);

  if (withinTmp36.1
'withinTmp' is 0
 && (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)((void)0);
      dctx->dictSize += dstSize;
      return;
  }

  if (withinTmp36.2
'withinTmp' is 0
) { /* copy relevant dict portion in front of tmpOut within tmpOutBuffer */
37
←
Taking false branch→
      size_t const preserveSize = (size_t)(dctx->tmpOut - dctx->tmpOutBuffer);
      size_t copySize = 64 KB*(1<<10) - dctx->tmpOutSize;
      const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart;
      if (dctx->tmpOutSize > 64 KB*(1<<10)) 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 */
38
←
Assuming field 'dict' is equal to field 'tmpOutBuffer'→
39
←
Taking true branch→
      if (dctx->dictSize + dstSize > dctx->maxBufferSize) {  /* tmp buffer not large enough */
40
←
Assuming the condition is false→
41
←
Taking false branch→
          size_t const preserveSize = 64 KB*(1<<10) - dstSize;
          memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize);
          dctx->dictSize = preserveSize;
      }
      memcpy(dctx->tmpOutBuffer + dctx->dictSize, dstPtr, dstSize);
42
←
Null pointer passed to 2nd parameter expecting 'nonnull'
      dctx->dictSize += dstSize;
      return;
  }

  /* join dict & dest into tmp */
  {   size_t preserveSize = 64 KB*(1<<10) - 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;
  }
1592}


1595/*! 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().
*/
1613size_t LZ4F_decompress(LZ4F_dctx* dctx,
                     void* dstBuffer, size_t* dstSizePtr,
                     const void* srcBuffer, size_t* srcSizePtr,
                     const LZ4F_decompressOptions_t* decompressOptionsPtr)
1617{
  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;
1
'dstStart' initialized here→
  BYTE* const dstEnd = dstStart ? dstStart + *dstSizePtr : NULL((void*)0);
2
←
Assuming 'dstStart' is null→
3
←
'?' condition is false→
  BYTE* dstPtr = dstStart;
4
←
'dstPtr' initialized to a null pointer value→
  const BYTE* selectedIn = NULL((void*)0);
  unsigned doAnotherStage = 1;
  size_t nextSrcSizeHint = 1;


  DEBUGLOG(5, "LZ4F_decompress: src[%p](%u) => dst[%p](%u)",{}
          srcBuffer, (unsigned)*srcSizePtr, dstBuffer, (unsigned)*dstSizePtr){};
  if (dstBuffer4.1
'dstBuffer' is equal to NULL
 == NULL((void*)0)) assert(*dstSizePtr == 0)((void)0);
5
←
Taking true branch→
  MEM_INIT(&optionsNull, 0, sizeof(optionsNull))memset((&optionsNull),(0),(sizeof(optionsNull)));
  if (decompressOptionsPtr==NULL((void*)0)) decompressOptionsPtr = &optionsNull;
6
←
Assuming 'decompressOptionsPtr' is not equal to NULL→
7
←
Taking false branch→
  *srcSizePtr = 0;
  *dstSizePtr = 0;
  assert(dctx != NULL)((void)0);
  dctx->skipChecksum |= (decompressOptionsPtr->skipChecksums != 0); /* once set, disable for the remainder of the frame */
8
←
Assuming field 'skipChecksums' is equal to 0→

  /* behaves as a state machine */

  while (doAnotherStage) {
9
←
Loop condition is true.  Entering loop body→

      switch(dctx->dStage)
10
←
Control jumps to 'case dstage_storeCBlock:'  at line 1851→
      {

      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)do { if (LZ4F_isError(hSize)) return (hSize); } while (0);
              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))( (dctx->tmpInTarget - dctx->tmpInSize) < ((size_t)(
srcEnd - srcPtr)) ? (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) )do { if (LZ4F_isError(LZ4F_decodeHeader(dctx, dctx->header
, dctx->tmpInTarget))) return (LZ4F_decodeHeader(dctx, dctx
->header, dctx->tmpInTarget)); } while (0); /* 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*(1<<10) : 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)do { if (dctx->tmpIn == ((void*)0)) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_allocation_failed); } } while (0);
                  LZ4F_free(dctx->tmpOutBuffer, dctx->cmem);
                  dctx->tmpOutBuffer= (BYTE*)LZ4F_malloc(bufferNeeded, dctx->cmem);
                  RETURN_ERROR_IF(dctx->tmpOutBuffer== NULL, allocation_failed)do { if (dctx->tmpOutBuffer== ((void*)0)) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_allocation_failed); } } while (0);
                  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)( (wantedData) < (remainingInput) ? (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)return LZ4F_returnErrorCode(LZ4F_ERROR_maxBlockSize_invalid);
              }
              if (blockHeader & LZ4F_BLOCKUNCOMPRESSED_FLAG0x80000000U) {
                  /* 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((void*)0)) {
                  sizeToCopy = 0;
              } else {
                  size_t const minBuffSize = MIN((size_t)(srcEnd-srcPtr), (size_t)(dstEnd-dstPtr))( ((size_t)(srcEnd-srcPtr)) < ((size_t)(dstEnd-dstPtr)) ? (
(size_t)(srcEnd-srcPtr)) : ((size_t)(dstEnd-dstPtr)) );
                  sizeToCopy = MIN(dctx->tmpInTarget, minBuffSize)( (dctx->tmpInTarget) < (minBuffSize) ? (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))( (stillToCopy) < ((size_t)(srcEnd-srcPtr)) ? (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);
1824#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)return LZ4F_returnErrorCode(LZ4F_ERROR_blockChecksum_invalid);
                  }
1831#else
                  (void)readCRC;
                  (void)calcCRC;
1834#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)( (wantedData) < (inputLeft) ? (wantedData) : (inputLeft) );
11
←
Assuming 'wantedData' is >= 'inputLeft'→
12
←
'?' condition is false→
              memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
              dctx->tmpInSize += sizeToCopy;
              srcPtr += sizeToCopy;
              if (dctx->tmpInSize < dctx->tmpInTarget) { /* need more input */
13
←
Assuming field 'tmpInSize' is >= field 'tmpInTarget'→
14
←
Taking false branch→
                  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) {
15
←
Assuming field 'blockChecksumFlag' is 0→
              assert(dctx->tmpInTarget >= 4)((void)0);
              dctx->tmpInTarget -= 4;
              assert(selectedIn != NULL)((void)0);  /* 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);
1877#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
                  RETURN_ERROR_IF(readBlockCrc != calcBlockCrc, blockChecksum_invalid)do { if (readBlockCrc != calcBlockCrc) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_blockChecksum_invalid); } } while (0);
1879#else
                  (void)readBlockCrc;
                  (void)calcBlockCrc;
1882#endif
          }   }

          /* decode directly into destination buffer if there is enough room */
          if ( ((size_t)(dstEnd-dstPtr) >= dctx->maxBlockSize)
16
←
Assuming the condition is true→
19
←
Taking true branch→
               /* 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((void*)0) && (const BYTE*)dctx->dict + dctx->dictSize == dctx->tmpOut) )
17
←
Assuming field 'dict' is not equal to NULL→
18
←
Assuming the condition is true→
          {
              const char* dict = (const char*)dctx->dict;
              size_t dictSize = dctx->dictSize;
              int decodedSize;
              assert(dstPtr != NULL)((void)0);
              if (dict19.1
'dict' is non-null
 && dictSize > 1 GB*(1<<30)) {
20
←
Assuming the condition is false→
21
←
Taking false branch→
                  /* overflow control : dctx->dictSize is an int, avoid truncation / sign issues */
                  dict += dictSize - 64 KB*(1<<10);
                  dictSize = 64 KB*(1<<10);
              }
              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)do { if (decodedSize < 0) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_decompressionFailed); } } while (0);
22
←
Assuming 'decodedSize' is >= 0→
23
←
Taking false branch→
              if ((dctx->frameInfo.contentChecksumFlag) && (!dctx->skipChecksum))
24
←
Loop condition is false.  Exiting loop→
25
←
Assuming field 'contentChecksumFlag' is 0→
                  XXH32_update(&(dctx->xxh), dstPtr, (size_t)decodedSize);
              if (dctx->frameInfo.contentSize)
26
←
Assuming field 'contentSize' is 0→
27
←
Taking false branch→
                  dctx->frameRemainingSize -= (size_t)decodedSize;

              /* dictionary management */
              if (dctx->frameInfo.blockMode==LZ4F_blockLinked) {
28
←
Assuming field 'blockMode' is equal to LZ4F_blockLinked→
29
←
Taking true branch→
                  LZ4F_updateDict(dctx, dstPtr, (size_t)decodedSize, dstStart, 0);
30
←
Passing null pointer value via 2nd parameter 'dstPtr'→
31
←
Calling 'LZ4F_updateDict'→
              }

              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*(1<<10)) {
                      memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - 64 KB*(1<<10), 64 KB*(1<<10));
                      dctx->dictSize = 64 KB*(1<<10);
                  }
                  dctx->tmpOut = dctx->tmpOutBuffer + dctx->dictSize;
              } else {  /* dict not within tmpOut */
                  size_t const reservedDictSpace = MIN(dctx->dictSize, 64 KB)( (dctx->dictSize) < (64 *(1<<10)) ? (dctx->dictSize
) : (64 *(1<<10)) );
                  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*(1<<30)) {
                  /* the dictSize param is an int, avoid truncation / sign issues */
                  dict += dictSize - 64 KB*(1<<10);
                  dictSize = 64 KB*(1<<10);
              }
              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)do { if (decodedSize < 0) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_decompressionFailed); } } while (0);
              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((void*)0)) {
              size_t const sizeToCopy = MIN(dctx->tmpOutSize - dctx->tmpOutStart, (size_t)(dstEnd-dstPtr))( (dctx->tmpOutSize - dctx->tmpOutStart) < ((size_t)
(dstEnd-dstPtr)) ? (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)do { if (dctx->frameRemainingSize) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_frameSize_wrong); } } while (0);   /* 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)( (wantedData) < (remainingInput) ? (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));
              DEBUGLOG(4, "frame checksum: stored 0x%0X vs 0x%0X processed", readCRC, resultCRC){};
2020#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
              RETURN_ERROR_IF(readCRC != resultCRC, contentChecksum_invalid)do { if (readCRC != resultCRC) { {}; return LZ4F_returnErrorCode
(LZ4F_ERROR_contentChecksum_invalid); } } while (0);
2022#else
              (void)readCRC;
              (void)resultCRC;
2025#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,( (dctx->tmpInTarget - dctx->tmpInSize) < ((size_t)(
srcEnd - srcPtr)) ? (dctx->tmpInTarget - dctx->tmpInSize
) : ((size_t)(srcEnd - srcPtr)) )
                                           (size_t)(srcEnd - srcPtr) )( (dctx->tmpInTarget - dctx->tmpInSize) < ((size_t)(
srcEnd - srcPtr)) ? (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))( (dctx->tmpInTarget) < ((size_t)(srcEnd-srcPtr)) ? (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){ enum { LZ4F_static_assert = 1/(int)(!!((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((void*)0))                           /* 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*(1<<10) - dctx->tmpOutSize;
          const BYTE* oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart;
          if (dctx->tmpOutSize > 64 KB*(1<<10)) copySize = 0;
          if (copySize > preserveSize) copySize = preserveSize;
          assert(dctx->tmpOutBuffer != NULL)((void)0);

          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)( (dctx->dictSize) < (64 *(1<<10)) ? (dctx->dictSize
) : (64 *(1<<10)) );

          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;
2116}

2118/*! 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.
*/
2123size_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)
2128{
  if (dctx->dStage <= dstage_init) {
      dctx->dict = (const BYTE*)dict;
      dctx->dictSize = dictSize;
  }
  return LZ4F_decompress(dctx, dstBuffer, dstSizePtr,
                         srcBuffer, srcSizePtr,
                         decompressOptionsPtr);
2136}