--- /dev/null
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+
+/* ***************************************************************
+* Tuning parameters
+*****************************************************************/
+/*!
+ * HEAPMODE :
+ * Select how default decompression function ZSTD_decompress() allocates its context,
+ * on stack (0), or into heap (1, default; requires malloc()).
+ * Note that functions with explicit context such as ZSTD_decompressDCtx() are unaffected.
+ */
+#ifndef ZSTD_HEAPMODE
+# define ZSTD_HEAPMODE 1
+#endif
+
+/*!
+* LEGACY_SUPPORT :
+* if set to 1+, ZSTD_decompress() can decode older formats (v0.1+)
+*/
+#ifndef ZSTD_LEGACY_SUPPORT
+# define ZSTD_LEGACY_SUPPORT 0
+#endif
+
+/*!
+ * MAXWINDOWSIZE_DEFAULT :
+ * maximum window size accepted by DStream __by default__.
+ * Frames requiring more memory will be rejected.
+ * It's possible to set a different limit using ZSTD_DCtx_setMaxWindowSize().
+ */
+#ifndef ZSTD_MAXWINDOWSIZE_DEFAULT
+# define ZSTD_MAXWINDOWSIZE_DEFAULT (((U32)1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT) + 1)
+#endif
+
+/*!
+ * NO_FORWARD_PROGRESS_MAX :
+ * maximum allowed nb of calls to ZSTD_decompressStream()
+ * without any forward progress
+ * (defined as: no byte read from input, and no byte flushed to output)
+ * before triggering an error.
+ */
+#ifndef ZSTD_NO_FORWARD_PROGRESS_MAX
+# define ZSTD_NO_FORWARD_PROGRESS_MAX 16
+#endif
+
+
+/*-*******************************************************
+* Dependencies
+*********************************************************/
+#include "../common/allocations.h" /* ZSTD_customMalloc, ZSTD_customCalloc, ZSTD_customFree */
+#include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memmove, ZSTD_memset */
+#include "../common/mem.h" /* low level memory routines */
+#define FSE_STATIC_LINKING_ONLY
+#include "../common/fse.h"
+#include "../common/huf.h"
+#include "../common/xxhash.h" /* XXH64_reset, XXH64_update, XXH64_digest, XXH64 */
+#include "../common/zstd_internal.h" /* blockProperties_t */
+#include "zstd_decompress_internal.h" /* ZSTD_DCtx */
+#include "zstd_ddict.h" /* ZSTD_DDictDictContent */
+#include "zstd_decompress_block.h" /* ZSTD_decompressBlock_internal */
+#include "../common/bits.h" /* ZSTD_highbit32 */
+
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+# include "../legacy/zstd_legacy.h"
+#endif
+
+
+
+/*************************************
+ * Multiple DDicts Hashset internals *
+ *************************************/
+
+#define DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT 4
+#define DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT 3 /* These two constants represent SIZE_MULT/COUNT_MULT load factor without using a float.
+ * Currently, that means a 0.75 load factor.
+ * So, if count * COUNT_MULT / size * SIZE_MULT != 0, then we've exceeded
+ * the load factor of the ddict hash set.
+ */
+
+#define DDICT_HASHSET_TABLE_BASE_SIZE 64
+#define DDICT_HASHSET_RESIZE_FACTOR 2
+
+/* Hash function to determine starting position of dict insertion within the table
+ * Returns an index between [0, hashSet->ddictPtrTableSize]
+ */
+static size_t ZSTD_DDictHashSet_getIndex(const ZSTD_DDictHashSet* hashSet, U32 dictID) {
+ const U64 hash = XXH64(&dictID, sizeof(U32), 0);
+ /* DDict ptr table size is a multiple of 2, use size - 1 as mask to get index within [0, hashSet->ddictPtrTableSize) */
+ return hash & (hashSet->ddictPtrTableSize - 1);
+}
+
+/* Adds DDict to a hashset without resizing it.
+ * If inserting a DDict with a dictID that already exists in the set, replaces the one in the set.
+ * Returns 0 if successful, or a zstd error code if something went wrong.
+ */
+static size_t ZSTD_DDictHashSet_emplaceDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict) {
+ const U32 dictID = ZSTD_getDictID_fromDDict(ddict);
+ size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID);
+ const size_t idxRangeMask = hashSet->ddictPtrTableSize - 1;
+ RETURN_ERROR_IF(hashSet->ddictPtrCount == hashSet->ddictPtrTableSize, GENERIC, "Hash set is full!");
+ DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx);
+ while (hashSet->ddictPtrTable[idx] != NULL) {
+ /* Replace existing ddict if inserting ddict with same dictID */
+ if (ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]) == dictID) {
+ DEBUGLOG(4, "DictID already exists, replacing rather than adding");
+ hashSet->ddictPtrTable[idx] = ddict;
+ return 0;
+ }
+ idx &= idxRangeMask;
+ idx++;
+ }
+ DEBUGLOG(4, "Final idx after probing for dictID %u is: %zu", dictID, idx);
+ hashSet->ddictPtrTable[idx] = ddict;
+ hashSet->ddictPtrCount++;
+ return 0;
+}
+
+/* Expands hash table by factor of DDICT_HASHSET_RESIZE_FACTOR and
+ * rehashes all values, allocates new table, frees old table.
+ * Returns 0 on success, otherwise a zstd error code.
+ */
+static size_t ZSTD_DDictHashSet_expand(ZSTD_DDictHashSet* hashSet, ZSTD_customMem customMem) {
+ size_t newTableSize = hashSet->ddictPtrTableSize * DDICT_HASHSET_RESIZE_FACTOR;
+ const ZSTD_DDict** newTable = (const ZSTD_DDict**)ZSTD_customCalloc(sizeof(ZSTD_DDict*) * newTableSize, customMem);
+ const ZSTD_DDict** oldTable = hashSet->ddictPtrTable;
+ size_t oldTableSize = hashSet->ddictPtrTableSize;
+ size_t i;
+
+ DEBUGLOG(4, "Expanding DDict hash table! Old size: %zu new size: %zu", oldTableSize, newTableSize);
+ RETURN_ERROR_IF(!newTable, memory_allocation, "Expanded hashset allocation failed!");
+ hashSet->ddictPtrTable = newTable;
+ hashSet->ddictPtrTableSize = newTableSize;
+ hashSet->ddictPtrCount = 0;
+ for (i = 0; i < oldTableSize; ++i) {
+ if (oldTable[i] != NULL) {
+ FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, oldTable[i]), "");
+ }
+ }
+ ZSTD_customFree((void*)oldTable, customMem);
+ DEBUGLOG(4, "Finished re-hash");
+ return 0;
+}
+
+/* Fetches a DDict with the given dictID
+ * Returns the ZSTD_DDict* with the requested dictID. If it doesn't exist, then returns NULL.
+ */
+static const ZSTD_DDict* ZSTD_DDictHashSet_getDDict(ZSTD_DDictHashSet* hashSet, U32 dictID) {
+ size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID);
+ const size_t idxRangeMask = hashSet->ddictPtrTableSize - 1;
+ DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx);
+ for (;;) {
+ size_t currDictID = ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]);
+ if (currDictID == dictID || currDictID == 0) {
+ /* currDictID == 0 implies a NULL ddict entry */
+ break;
+ } else {
+ idx &= idxRangeMask; /* Goes to start of table when we reach the end */
+ idx++;
+ }
+ }
+ DEBUGLOG(4, "Final idx after probing for dictID %u is: %zu", dictID, idx);
+ return hashSet->ddictPtrTable[idx];
+}
+
+/* Allocates space for and returns a ddict hash set
+ * The hash set's ZSTD_DDict* table has all values automatically set to NULL to begin with.
+ * Returns NULL if allocation failed.
+ */
+static ZSTD_DDictHashSet* ZSTD_createDDictHashSet(ZSTD_customMem customMem) {
+ ZSTD_DDictHashSet* ret = (ZSTD_DDictHashSet*)ZSTD_customMalloc(sizeof(ZSTD_DDictHashSet), customMem);
+ DEBUGLOG(4, "Allocating new hash set");
+ if (!ret)
+ return NULL;
+ ret->ddictPtrTable = (const ZSTD_DDict**)ZSTD_customCalloc(DDICT_HASHSET_TABLE_BASE_SIZE * sizeof(ZSTD_DDict*), customMem);
+ if (!ret->ddictPtrTable) {
+ ZSTD_customFree(ret, customMem);
+ return NULL;
+ }
+ ret->ddictPtrTableSize = DDICT_HASHSET_TABLE_BASE_SIZE;
+ ret->ddictPtrCount = 0;
+ return ret;
+}
+
+/* Frees the table of ZSTD_DDict* within a hashset, then frees the hashset itself.
+ * Note: The ZSTD_DDict* within the table are NOT freed.
+ */
+static void ZSTD_freeDDictHashSet(ZSTD_DDictHashSet* hashSet, ZSTD_customMem customMem) {
+ DEBUGLOG(4, "Freeing ddict hash set");
+ if (hashSet && hashSet->ddictPtrTable) {
+ ZSTD_customFree((void*)hashSet->ddictPtrTable, customMem);
+ }
+ if (hashSet) {
+ ZSTD_customFree(hashSet, customMem);
+ }
+}
+
+/* Public function: Adds a DDict into the ZSTD_DDictHashSet, possibly triggering a resize of the hash set.
+ * Returns 0 on success, or a ZSTD error.
+ */
+static size_t ZSTD_DDictHashSet_addDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict, ZSTD_customMem customMem) {
+ DEBUGLOG(4, "Adding dict ID: %u to hashset with - Count: %zu Tablesize: %zu", ZSTD_getDictID_fromDDict(ddict), hashSet->ddictPtrCount, hashSet->ddictPtrTableSize);
+ if (hashSet->ddictPtrCount * DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT / hashSet->ddictPtrTableSize * DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT != 0) {
+ FORWARD_IF_ERROR(ZSTD_DDictHashSet_expand(hashSet, customMem), "");
+ }
+ FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, ddict), "");
+ return 0;
+}
+
+/*-*************************************************************
+* Context management
+***************************************************************/
+size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx)
+{
+ if (dctx==NULL) return 0; /* support sizeof NULL */
+ return sizeof(*dctx)
+ + ZSTD_sizeof_DDict(dctx->ddictLocal)
+ + dctx->inBuffSize + dctx->outBuffSize;
+}
+
+size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); }
+
+
+static size_t ZSTD_startingInputLength(ZSTD_format_e format)
+{
+ size_t const startingInputLength = ZSTD_FRAMEHEADERSIZE_PREFIX(format);
+ /* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */
+ assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) );
+ return startingInputLength;
+}
+
+static void ZSTD_DCtx_resetParameters(ZSTD_DCtx* dctx)
+{
+ assert(dctx->streamStage == zdss_init);
+ dctx->format = ZSTD_f_zstd1;
+ dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
+ dctx->outBufferMode = ZSTD_bm_buffered;
+ dctx->forceIgnoreChecksum = ZSTD_d_validateChecksum;
+ dctx->refMultipleDDicts = ZSTD_rmd_refSingleDDict;
+ dctx->disableHufAsm = 0;
+}
+
+static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx)
+{
+ dctx->staticSize = 0;
+ dctx->ddict = NULL;
+ dctx->ddictLocal = NULL;
+ dctx->dictEnd = NULL;
+ dctx->ddictIsCold = 0;
+ dctx->dictUses = ZSTD_dont_use;
+ dctx->inBuff = NULL;
+ dctx->inBuffSize = 0;
+ dctx->outBuffSize = 0;
+ dctx->streamStage = zdss_init;
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+ dctx->legacyContext = NULL;
+ dctx->previousLegacyVersion = 0;
+#endif
+ dctx->noForwardProgress = 0;
+ dctx->oversizedDuration = 0;
+#if DYNAMIC_BMI2
+ dctx->bmi2 = ZSTD_cpuSupportsBmi2();
+#endif
+ dctx->ddictSet = NULL;
+ ZSTD_DCtx_resetParameters(dctx);
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ dctx->dictContentEndForFuzzing = NULL;
+#endif
+}
+
+ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize)
+{
+ ZSTD_DCtx* const dctx = (ZSTD_DCtx*) workspace;
+
+ if ((size_t)workspace & 7) return NULL; /* 8-aligned */
+ if (workspaceSize < sizeof(ZSTD_DCtx)) return NULL; /* minimum size */
+
+ ZSTD_initDCtx_internal(dctx);
+ dctx->staticSize = workspaceSize;
+ dctx->inBuff = (char*)(dctx+1);
+ return dctx;
+}
+
+static ZSTD_DCtx* ZSTD_createDCtx_internal(ZSTD_customMem customMem) {
+ if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL;
+
+ { ZSTD_DCtx* const dctx = (ZSTD_DCtx*)ZSTD_customMalloc(sizeof(*dctx), customMem);
+ if (!dctx) return NULL;
+ dctx->customMem = customMem;
+ ZSTD_initDCtx_internal(dctx);
+ return dctx;
+ }
+}
+
+ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
+{
+ return ZSTD_createDCtx_internal(customMem);
+}
+
+ZSTD_DCtx* ZSTD_createDCtx(void)
+{
+ DEBUGLOG(3, "ZSTD_createDCtx");
+ return ZSTD_createDCtx_internal(ZSTD_defaultCMem);
+}
+
+static void ZSTD_clearDict(ZSTD_DCtx* dctx)
+{
+ ZSTD_freeDDict(dctx->ddictLocal);
+ dctx->ddictLocal = NULL;
+ dctx->ddict = NULL;
+ dctx->dictUses = ZSTD_dont_use;
+}
+
+size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
+{
+ if (dctx==NULL) return 0; /* support free on NULL */
+ RETURN_ERROR_IF(dctx->staticSize, memory_allocation, "not compatible with static DCtx");
+ { ZSTD_customMem const cMem = dctx->customMem;
+ ZSTD_clearDict(dctx);
+ ZSTD_customFree(dctx->inBuff, cMem);
+ dctx->inBuff = NULL;
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
+ if (dctx->legacyContext)
+ ZSTD_freeLegacyStreamContext(dctx->legacyContext, dctx->previousLegacyVersion);
+#endif
+ if (dctx->ddictSet) {
+ ZSTD_freeDDictHashSet(dctx->ddictSet, cMem);
+ dctx->ddictSet = NULL;
+ }
+ ZSTD_customFree(dctx, cMem);
+ return 0;
+ }
+}
+
+/* no longer useful */
+void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
+{
+ size_t const toCopy = (size_t)((char*)(&dstDCtx->inBuff) - (char*)dstDCtx);
+ ZSTD_memcpy(dstDCtx, srcDCtx, toCopy); /* no need to copy workspace */
+}
+
+/* Given a dctx with a digested frame params, re-selects the correct ZSTD_DDict based on
+ * the requested dict ID from the frame. If there exists a reference to the correct ZSTD_DDict, then
+ * accordingly sets the ddict to be used to decompress the frame.
+ *
+ * If no DDict is found, then no action is taken, and the ZSTD_DCtx::ddict remains as-is.
+ *
+ * ZSTD_d_refMultipleDDicts must be enabled for this function to be called.
+ */
+static void ZSTD_DCtx_selectFrameDDict(ZSTD_DCtx* dctx) {
+ assert(dctx->refMultipleDDicts && dctx->ddictSet);
+ DEBUGLOG(4, "Adjusting DDict based on requested dict ID from frame");
+ if (dctx->ddict) {
+ const ZSTD_DDict* frameDDict = ZSTD_DDictHashSet_getDDict(dctx->ddictSet, dctx->fParams.dictID);
+ if (frameDDict) {
+ DEBUGLOG(4, "DDict found!");
+ ZSTD_clearDict(dctx);
+ dctx->dictID = dctx->fParams.dictID;
+ dctx->ddict = frameDDict;
+ dctx->dictUses = ZSTD_use_indefinitely;
+ }
+ }
+}
+
+
+/*-*************************************************************
+ * Frame header decoding
+ ***************************************************************/
+
+/*! ZSTD_isFrame() :
+ * Tells if the content of `buffer` starts with a valid Frame Identifier.
+ * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
+ * Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
+ * Note 3 : Skippable Frame Identifiers are considered valid. */
+unsigned ZSTD_isFrame(const void* buffer, size_t size)
+{
+ if (size < ZSTD_FRAMEIDSIZE) return 0;
+ { U32 const magic = MEM_readLE32(buffer);
+ if (magic == ZSTD_MAGICNUMBER) return 1;
+ if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1;
+ }
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
+ if (ZSTD_isLegacy(buffer, size)) return 1;
+#endif
+ return 0;
+}
+
+/*! ZSTD_isSkippableFrame() :
+ * Tells if the content of `buffer` starts with a valid Frame Identifier for a skippable frame.
+ * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
+ */
+unsigned ZSTD_isSkippableFrame(const void* buffer, size_t size)
+{
+ if (size < ZSTD_FRAMEIDSIZE) return 0;
+ { U32 const magic = MEM_readLE32(buffer);
+ if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1;
+ }
+ return 0;
+}
+
+/** ZSTD_frameHeaderSize_internal() :
+ * srcSize must be large enough to reach header size fields.
+ * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless.
+ * @return : size of the Frame Header
+ * or an error code, which can be tested with ZSTD_isError() */
+static size_t ZSTD_frameHeaderSize_internal(const void* src, size_t srcSize, ZSTD_format_e format)
+{
+ size_t const minInputSize = ZSTD_startingInputLength(format);
+ RETURN_ERROR_IF(srcSize < minInputSize, srcSize_wrong, "");
+
+ { BYTE const fhd = ((const BYTE*)src)[minInputSize-1];
+ U32 const dictID= fhd & 3;
+ U32 const singleSegment = (fhd >> 5) & 1;
+ U32 const fcsId = fhd >> 6;
+ return minInputSize + !singleSegment
+ + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId]
+ + (singleSegment && !fcsId);
+ }
+}
+
+/** ZSTD_frameHeaderSize() :
+ * srcSize must be >= ZSTD_frameHeaderSize_prefix.
+ * @return : size of the Frame Header,
+ * or an error code (if srcSize is too small) */
+size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize)
+{
+ return ZSTD_frameHeaderSize_internal(src, srcSize, ZSTD_f_zstd1);
+}
+
+
+/** ZSTD_getFrameHeader_advanced() :
+ * decode Frame Header, or require larger `srcSize`.
+ * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless
+ * @return : 0, `zfhPtr` is correctly filled,
+ * >0, `srcSize` is too small, value is wanted `srcSize` amount,
+** or an error code, which can be tested using ZSTD_isError() */
+size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format)
+{
+ const BYTE* ip = (const BYTE*)src;
+ size_t const minInputSize = ZSTD_startingInputLength(format);
+
+ DEBUGLOG(5, "ZSTD_getFrameHeader_advanced: minInputSize = %zu, srcSize = %zu", minInputSize, srcSize);
+
+ if (srcSize > 0) {
+ /* note : technically could be considered an assert(), since it's an invalid entry */
+ RETURN_ERROR_IF(src==NULL, GENERIC, "invalid parameter : src==NULL, but srcSize>0");
+ }
+ if (srcSize < minInputSize) {
+ if (srcSize > 0 && format != ZSTD_f_zstd1_magicless) {
+ /* when receiving less than @minInputSize bytes,
+ * control these bytes at least correspond to a supported magic number
+ * in order to error out early if they don't.
+ **/
+ size_t const toCopy = MIN(4, srcSize);
+ unsigned char hbuf[4]; MEM_writeLE32(hbuf, ZSTD_MAGICNUMBER);
+ assert(src != NULL);
+ ZSTD_memcpy(hbuf, src, toCopy);
+ if ( MEM_readLE32(hbuf) != ZSTD_MAGICNUMBER ) {
+ /* not a zstd frame : let's check if it's a skippable frame */
+ MEM_writeLE32(hbuf, ZSTD_MAGIC_SKIPPABLE_START);
+ ZSTD_memcpy(hbuf, src, toCopy);
+ if ((MEM_readLE32(hbuf) & ZSTD_MAGIC_SKIPPABLE_MASK) != ZSTD_MAGIC_SKIPPABLE_START) {
+ RETURN_ERROR(prefix_unknown,
+ "first bytes don't correspond to any supported magic number");
+ } } }
+ return minInputSize;
+ }
+
+ ZSTD_memset(zfhPtr, 0, sizeof(*zfhPtr)); /* not strictly necessary, but static analyzers may not understand that zfhPtr will be read only if return value is zero, since they are 2 different signals */
+ if ( (format != ZSTD_f_zstd1_magicless)
+ && (MEM_readLE32(src) != ZSTD_MAGICNUMBER) ) {
+ if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
+ /* skippable frame */
+ if (srcSize < ZSTD_SKIPPABLEHEADERSIZE)
+ return ZSTD_SKIPPABLEHEADERSIZE; /* magic number + frame length */
+ ZSTD_memset(zfhPtr, 0, sizeof(*zfhPtr));
+ zfhPtr->frameContentSize = MEM_readLE32((const char *)src + ZSTD_FRAMEIDSIZE);
+ zfhPtr->frameType = ZSTD_skippableFrame;
+ return 0;
+ }
+ RETURN_ERROR(prefix_unknown, "");
+ }
+
+ /* ensure there is enough `srcSize` to fully read/decode frame header */
+ { size_t const fhsize = ZSTD_frameHeaderSize_internal(src, srcSize, format);
+ if (srcSize < fhsize) return fhsize;
+ zfhPtr->headerSize = (U32)fhsize;
+ }
+
+ { BYTE const fhdByte = ip[minInputSize-1];
+ size_t pos = minInputSize;
+ U32 const dictIDSizeCode = fhdByte&3;
+ U32 const checksumFlag = (fhdByte>>2)&1;
+ U32 const singleSegment = (fhdByte>>5)&1;
+ U32 const fcsID = fhdByte>>6;
+ U64 windowSize = 0;
+ U32 dictID = 0;
+ U64 frameContentSize = ZSTD_CONTENTSIZE_UNKNOWN;
+ RETURN_ERROR_IF((fhdByte & 0x08) != 0, frameParameter_unsupported,
+ "reserved bits, must be zero");
+
+ if (!singleSegment) {
+ BYTE const wlByte = ip[pos++];
+ U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN;
+ RETURN_ERROR_IF(windowLog > ZSTD_WINDOWLOG_MAX, frameParameter_windowTooLarge, "");
+ windowSize = (1ULL << windowLog);
+ windowSize += (windowSize >> 3) * (wlByte&7);
+ }
+ switch(dictIDSizeCode)
+ {
+ default:
+ assert(0); /* impossible */
+ ZSTD_FALLTHROUGH;
+ case 0 : break;
+ case 1 : dictID = ip[pos]; pos++; break;
+ case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break;
+ case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break;
+ }
+ switch(fcsID)
+ {
+ default:
+ assert(0); /* impossible */
+ ZSTD_FALLTHROUGH;
+ case 0 : if (singleSegment) frameContentSize = ip[pos]; break;
+ case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break;
+ case 2 : frameContentSize = MEM_readLE32(ip+pos); break;
+ case 3 : frameContentSize = MEM_readLE64(ip+pos); break;
+ }
+ if (singleSegment) windowSize = frameContentSize;
+
+ zfhPtr->frameType = ZSTD_frame;
+ zfhPtr->frameContentSize = frameContentSize;
+ zfhPtr->windowSize = windowSize;
+ zfhPtr->blockSizeMax = (unsigned) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
+ zfhPtr->dictID = dictID;
+ zfhPtr->checksumFlag = checksumFlag;
+ }
+ return 0;
+}
+
+/** ZSTD_getFrameHeader() :
+ * decode Frame Header, or require larger `srcSize`.
+ * note : this function does not consume input, it only reads it.
+ * @return : 0, `zfhPtr` is correctly filled,
+ * >0, `srcSize` is too small, value is wanted `srcSize` amount,
+ * or an error code, which can be tested using ZSTD_isError() */
+size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize)
+{
+ return ZSTD_getFrameHeader_advanced(zfhPtr, src, srcSize, ZSTD_f_zstd1);
+}
+
+/** ZSTD_getFrameContentSize() :
+ * compatible with legacy mode
+ * @return : decompressed size of the single frame pointed to be `src` if known, otherwise
+ * - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
+ * - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */
+unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize)
+{
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
+ if (ZSTD_isLegacy(src, srcSize)) {
+ unsigned long long const ret = ZSTD_getDecompressedSize_legacy(src, srcSize);
+ return ret == 0 ? ZSTD_CONTENTSIZE_UNKNOWN : ret;
+ }
+#endif
+ { ZSTD_frameHeader zfh;
+ if (ZSTD_getFrameHeader(&zfh, src, srcSize) != 0)
+ return ZSTD_CONTENTSIZE_ERROR;
+ if (zfh.frameType == ZSTD_skippableFrame) {
+ return 0;
+ } else {
+ return zfh.frameContentSize;
+ } }
+}
+
+static size_t readSkippableFrameSize(void const* src, size_t srcSize)
+{
+ size_t const skippableHeaderSize = ZSTD_SKIPPABLEHEADERSIZE;
+ U32 sizeU32;
+
+ RETURN_ERROR_IF(srcSize < ZSTD_SKIPPABLEHEADERSIZE, srcSize_wrong, "");
+
+ sizeU32 = MEM_readLE32((BYTE const*)src + ZSTD_FRAMEIDSIZE);
+ RETURN_ERROR_IF((U32)(sizeU32 + ZSTD_SKIPPABLEHEADERSIZE) < sizeU32,
+ frameParameter_unsupported, "");
+ { size_t const skippableSize = skippableHeaderSize + sizeU32;
+ RETURN_ERROR_IF(skippableSize > srcSize, srcSize_wrong, "");
+ return skippableSize;
+ }
+}
+
+/*! ZSTD_readSkippableFrame() :
+ * Retrieves content of a skippable frame, and writes it to dst buffer.
+ *
+ * The parameter magicVariant will receive the magicVariant that was supplied when the frame was written,
+ * i.e. magicNumber - ZSTD_MAGIC_SKIPPABLE_START. This can be NULL if the caller is not interested
+ * in the magicVariant.
+ *
+ * Returns an error if destination buffer is not large enough, or if this is not a valid skippable frame.
+ *
+ * @return : number of bytes written or a ZSTD error.
+ */
+size_t ZSTD_readSkippableFrame(void* dst, size_t dstCapacity,
+ unsigned* magicVariant, /* optional, can be NULL */
+ const void* src, size_t srcSize)
+{
+ RETURN_ERROR_IF(srcSize < ZSTD_SKIPPABLEHEADERSIZE, srcSize_wrong, "");
+
+ { U32 const magicNumber = MEM_readLE32(src);
+ size_t skippableFrameSize = readSkippableFrameSize(src, srcSize);
+ size_t skippableContentSize = skippableFrameSize - ZSTD_SKIPPABLEHEADERSIZE;
+
+ /* check input validity */
+ RETURN_ERROR_IF(!ZSTD_isSkippableFrame(src, srcSize), frameParameter_unsupported, "");
+ RETURN_ERROR_IF(skippableFrameSize < ZSTD_SKIPPABLEHEADERSIZE || skippableFrameSize > srcSize, srcSize_wrong, "");
+ RETURN_ERROR_IF(skippableContentSize > dstCapacity, dstSize_tooSmall, "");
+
+ /* deliver payload */
+ if (skippableContentSize > 0 && dst != NULL)
+ ZSTD_memcpy(dst, (const BYTE *)src + ZSTD_SKIPPABLEHEADERSIZE, skippableContentSize);
+ if (magicVariant != NULL)
+ *magicVariant = magicNumber - ZSTD_MAGIC_SKIPPABLE_START;
+ return skippableContentSize;
+ }
+}
+
+/** ZSTD_findDecompressedSize() :
+ * `srcSize` must be the exact length of some number of ZSTD compressed and/or
+ * skippable frames
+ * note: compatible with legacy mode
+ * @return : decompressed size of the frames contained */
+unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize)
+{
+ unsigned long long totalDstSize = 0;
+
+ while (srcSize >= ZSTD_startingInputLength(ZSTD_f_zstd1)) {
+ U32 const magicNumber = MEM_readLE32(src);
+
+ if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
+ size_t const skippableSize = readSkippableFrameSize(src, srcSize);
+ if (ZSTD_isError(skippableSize)) return ZSTD_CONTENTSIZE_ERROR;
+ assert(skippableSize <= srcSize);
+
+ src = (const BYTE *)src + skippableSize;
+ srcSize -= skippableSize;
+ continue;
+ }
+
+ { unsigned long long const fcs = ZSTD_getFrameContentSize(src, srcSize);
+ if (fcs >= ZSTD_CONTENTSIZE_ERROR) return fcs;
+
+ if (totalDstSize + fcs < totalDstSize)
+ return ZSTD_CONTENTSIZE_ERROR; /* check for overflow */
+ totalDstSize += fcs;
+ }
+ /* skip to next frame */
+ { size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize);
+ if (ZSTD_isError(frameSrcSize)) return ZSTD_CONTENTSIZE_ERROR;
+ assert(frameSrcSize <= srcSize);
+
+ src = (const BYTE *)src + frameSrcSize;
+ srcSize -= frameSrcSize;
+ }
+ } /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */
+
+ if (srcSize) return ZSTD_CONTENTSIZE_ERROR;
+
+ return totalDstSize;
+}
+
+/** ZSTD_getDecompressedSize() :
+ * compatible with legacy mode
+ * @return : decompressed size if known, 0 otherwise
+ note : 0 can mean any of the following :
+ - frame content is empty
+ - decompressed size field is not present in frame header
+ - frame header unknown / not supported
+ - frame header not complete (`srcSize` too small) */
+unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize)
+{
+ unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
+ ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_ERROR < ZSTD_CONTENTSIZE_UNKNOWN);
+ return (ret >= ZSTD_CONTENTSIZE_ERROR) ? 0 : ret;
+}
+
+
+/** ZSTD_decodeFrameHeader() :
+ * `headerSize` must be the size provided by ZSTD_frameHeaderSize().
+ * If multiple DDict references are enabled, also will choose the correct DDict to use.
+ * @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */
+static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t headerSize)
+{
+ size_t const result = ZSTD_getFrameHeader_advanced(&(dctx->fParams), src, headerSize, dctx->format);
+ if (ZSTD_isError(result)) return result; /* invalid header */
+ RETURN_ERROR_IF(result>0, srcSize_wrong, "headerSize too small");
+
+ /* Reference DDict requested by frame if dctx references multiple ddicts */
+ if (dctx->refMultipleDDicts == ZSTD_rmd_refMultipleDDicts && dctx->ddictSet) {
+ ZSTD_DCtx_selectFrameDDict(dctx);
+ }
+
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ /* Skip the dictID check in fuzzing mode, because it makes the search
+ * harder.
+ */
+ RETURN_ERROR_IF(dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID),
+ dictionary_wrong, "");
+#endif
+ dctx->validateChecksum = (dctx->fParams.checksumFlag && !dctx->forceIgnoreChecksum) ? 1 : 0;
+ if (dctx->validateChecksum) XXH64_reset(&dctx->xxhState, 0);
+ dctx->processedCSize += headerSize;
+ return 0;
+}
+
+static ZSTD_frameSizeInfo ZSTD_errorFrameSizeInfo(size_t ret)
+{
+ ZSTD_frameSizeInfo frameSizeInfo;
+ frameSizeInfo.compressedSize = ret;
+ frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR;
+ return frameSizeInfo;
+}
+
+static ZSTD_frameSizeInfo ZSTD_findFrameSizeInfo(const void* src, size_t srcSize)
+{
+ ZSTD_frameSizeInfo frameSizeInfo;
+ ZSTD_memset(&frameSizeInfo, 0, sizeof(ZSTD_frameSizeInfo));
+
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
+ if (ZSTD_isLegacy(src, srcSize))
+ return ZSTD_findFrameSizeInfoLegacy(src, srcSize);
+#endif
+
+ if ((srcSize >= ZSTD_SKIPPABLEHEADERSIZE)
+ && (MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
+ frameSizeInfo.compressedSize = readSkippableFrameSize(src, srcSize);
+ assert(ZSTD_isError(frameSizeInfo.compressedSize) ||
+ frameSizeInfo.compressedSize <= srcSize);
+ return frameSizeInfo;
+ } else {
+ const BYTE* ip = (const BYTE*)src;
+ const BYTE* const ipstart = ip;
+ size_t remainingSize = srcSize;
+ size_t nbBlocks = 0;
+ ZSTD_frameHeader zfh;
+
+ /* Extract Frame Header */
+ { size_t const ret = ZSTD_getFrameHeader(&zfh, src, srcSize);
+ if (ZSTD_isError(ret))
+ return ZSTD_errorFrameSizeInfo(ret);
+ if (ret > 0)
+ return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
+ }
+
+ ip += zfh.headerSize;
+ remainingSize -= zfh.headerSize;
+
+ /* Iterate over each block */
+ while (1) {
+ blockProperties_t blockProperties;
+ size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
+ if (ZSTD_isError(cBlockSize))
+ return ZSTD_errorFrameSizeInfo(cBlockSize);
+
+ if (ZSTD_blockHeaderSize + cBlockSize > remainingSize)
+ return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
+
+ ip += ZSTD_blockHeaderSize + cBlockSize;
+ remainingSize -= ZSTD_blockHeaderSize + cBlockSize;
+ nbBlocks++;
+
+ if (blockProperties.lastBlock) break;
+ }
+
+ /* Final frame content checksum */
+ if (zfh.checksumFlag) {
+ if (remainingSize < 4)
+ return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
+ ip += 4;
+ }
+
+ frameSizeInfo.nbBlocks = nbBlocks;
+ frameSizeInfo.compressedSize = (size_t)(ip - ipstart);
+ frameSizeInfo.decompressedBound = (zfh.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN)
+ ? zfh.frameContentSize
+ : (unsigned long long)nbBlocks * zfh.blockSizeMax;
+ return frameSizeInfo;
+ }
+}
+
+/** ZSTD_findFrameCompressedSize() :
+ * compatible with legacy mode
+ * `src` must point to the start of a ZSTD frame, ZSTD legacy frame, or skippable frame
+ * `srcSize` must be at least as large as the frame contained
+ * @return : the compressed size of the frame starting at `src` */
+size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
+{
+ ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize);
+ return frameSizeInfo.compressedSize;
+}
+
+/** ZSTD_decompressBound() :
+ * compatible with legacy mode
+ * `src` must point to the start of a ZSTD frame or a skippeable frame
+ * `srcSize` must be at least as large as the frame contained
+ * @return : the maximum decompressed size of the compressed source
+ */
+unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize)
+{
+ unsigned long long bound = 0;
+ /* Iterate over each frame */
+ while (srcSize > 0) {
+ ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize);
+ size_t const compressedSize = frameSizeInfo.compressedSize;
+ unsigned long long const decompressedBound = frameSizeInfo.decompressedBound;
+ if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR)
+ return ZSTD_CONTENTSIZE_ERROR;
+ assert(srcSize >= compressedSize);
+ src = (const BYTE*)src + compressedSize;
+ srcSize -= compressedSize;
+ bound += decompressedBound;
+ }
+ return bound;
+}
+
+size_t ZSTD_decompressionMargin(void const* src, size_t srcSize)
+{
+ size_t margin = 0;
+ unsigned maxBlockSize = 0;
+
+ /* Iterate over each frame */
+ while (srcSize > 0) {
+ ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize);
+ size_t const compressedSize = frameSizeInfo.compressedSize;
+ unsigned long long const decompressedBound = frameSizeInfo.decompressedBound;
+ ZSTD_frameHeader zfh;
+
+ FORWARD_IF_ERROR(ZSTD_getFrameHeader(&zfh, src, srcSize), "");
+ if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR)
+ return ERROR(corruption_detected);
+
+ if (zfh.frameType == ZSTD_frame) {
+ /* Add the frame header to our margin */
+ margin += zfh.headerSize;
+ /* Add the checksum to our margin */
+ margin += zfh.checksumFlag ? 4 : 0;
+ /* Add 3 bytes per block */
+ margin += 3 * frameSizeInfo.nbBlocks;
+
+ /* Compute the max block size */
+ maxBlockSize = MAX(maxBlockSize, zfh.blockSizeMax);
+ } else {
+ assert(zfh.frameType == ZSTD_skippableFrame);
+ /* Add the entire skippable frame size to our margin. */
+ margin += compressedSize;
+ }
+
+ assert(srcSize >= compressedSize);
+ src = (const BYTE*)src + compressedSize;
+ srcSize -= compressedSize;
+ }
+
+ /* Add the max block size back to the margin. */
+ margin += maxBlockSize;
+
+ return margin;
+}
+
+/*-*************************************************************
+ * Frame decoding
+ ***************************************************************/
+
+/** ZSTD_insertBlock() :
+ * insert `src` block into `dctx` history. Useful to track uncompressed blocks. */
+size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize)
+{
+ DEBUGLOG(5, "ZSTD_insertBlock: %u bytes", (unsigned)blockSize);
+ ZSTD_checkContinuity(dctx, blockStart, blockSize);
+ dctx->previousDstEnd = (const char*)blockStart + blockSize;
+ return blockSize;
+}
+
+
+static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize)
+{
+ DEBUGLOG(5, "ZSTD_copyRawBlock");
+ RETURN_ERROR_IF(srcSize > dstCapacity, dstSize_tooSmall, "");
+ if (dst == NULL) {
+ if (srcSize == 0) return 0;
+ RETURN_ERROR(dstBuffer_null, "");
+ }
+ ZSTD_memmove(dst, src, srcSize);
+ return srcSize;
+}
+
+static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity,
+ BYTE b,
+ size_t regenSize)
+{
+ RETURN_ERROR_IF(regenSize > dstCapacity, dstSize_tooSmall, "");
+ if (dst == NULL) {
+ if (regenSize == 0) return 0;
+ RETURN_ERROR(dstBuffer_null, "");
+ }
+ ZSTD_memset(dst, b, regenSize);
+ return regenSize;
+}
+
+static void ZSTD_DCtx_trace_end(ZSTD_DCtx const* dctx, U64 uncompressedSize, U64 compressedSize, unsigned streaming)
+{
+#if ZSTD_TRACE
+ if (dctx->traceCtx && ZSTD_trace_decompress_end != NULL) {
+ ZSTD_Trace trace;
+ ZSTD_memset(&trace, 0, sizeof(trace));
+ trace.version = ZSTD_VERSION_NUMBER;
+ trace.streaming = streaming;
+ if (dctx->ddict) {
+ trace.dictionaryID = ZSTD_getDictID_fromDDict(dctx->ddict);
+ trace.dictionarySize = ZSTD_DDict_dictSize(dctx->ddict);
+ trace.dictionaryIsCold = dctx->ddictIsCold;
+ }
+ trace.uncompressedSize = (size_t)uncompressedSize;
+ trace.compressedSize = (size_t)compressedSize;
+ trace.dctx = dctx;
+ ZSTD_trace_decompress_end(dctx->traceCtx, &trace);
+ }
+#else
+ (void)dctx;
+ (void)uncompressedSize;
+ (void)compressedSize;
+ (void)streaming;
+#endif
+}
+
+
+/*! ZSTD_decompressFrame() :
+ * @dctx must be properly initialized
+ * will update *srcPtr and *srcSizePtr,
+ * to make *srcPtr progress by one frame. */
+static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void** srcPtr, size_t *srcSizePtr)
+{
+ const BYTE* const istart = (const BYTE*)(*srcPtr);
+ const BYTE* ip = istart;
+ BYTE* const ostart = (BYTE*)dst;
+ BYTE* const oend = dstCapacity != 0 ? ostart + dstCapacity : ostart;
+ BYTE* op = ostart;
+ size_t remainingSrcSize = *srcSizePtr;
+
+ DEBUGLOG(4, "ZSTD_decompressFrame (srcSize:%i)", (int)*srcSizePtr);
+
+ /* check */
+ RETURN_ERROR_IF(
+ remainingSrcSize < ZSTD_FRAMEHEADERSIZE_MIN(dctx->format)+ZSTD_blockHeaderSize,
+ srcSize_wrong, "");
+
+ /* Frame Header */
+ { size_t const frameHeaderSize = ZSTD_frameHeaderSize_internal(
+ ip, ZSTD_FRAMEHEADERSIZE_PREFIX(dctx->format), dctx->format);
+ if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
+ RETURN_ERROR_IF(remainingSrcSize < frameHeaderSize+ZSTD_blockHeaderSize,
+ srcSize_wrong, "");
+ FORWARD_IF_ERROR( ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize) , "");
+ ip += frameHeaderSize; remainingSrcSize -= frameHeaderSize;
+ }
+
+ /* Loop on each block */
+ while (1) {
+ BYTE* oBlockEnd = oend;
+ size_t decodedSize;
+ blockProperties_t blockProperties;
+ size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSrcSize, &blockProperties);
+ if (ZSTD_isError(cBlockSize)) return cBlockSize;
+
+ ip += ZSTD_blockHeaderSize;
+ remainingSrcSize -= ZSTD_blockHeaderSize;
+ RETURN_ERROR_IF(cBlockSize > remainingSrcSize, srcSize_wrong, "");
+
+ if (ip >= op && ip < oBlockEnd) {
+ /* We are decompressing in-place. Limit the output pointer so that we
+ * don't overwrite the block that we are currently reading. This will
+ * fail decompression if the input & output pointers aren't spaced
+ * far enough apart.
+ *
+ * This is important to set, even when the pointers are far enough
+ * apart, because ZSTD_decompressBlock_internal() can decide to store
+ * literals in the output buffer, after the block it is decompressing.
+ * Since we don't want anything to overwrite our input, we have to tell
+ * ZSTD_decompressBlock_internal to never write past ip.
+ *
+ * See ZSTD_allocateLiteralsBuffer() for reference.
+ */
+ oBlockEnd = op + (ip - op);
+ }
+
+ switch(blockProperties.blockType)
+ {
+ case bt_compressed:
+ decodedSize = ZSTD_decompressBlock_internal(dctx, op, (size_t)(oBlockEnd-op), ip, cBlockSize, /* frame */ 1, not_streaming);
+ break;
+ case bt_raw :
+ /* Use oend instead of oBlockEnd because this function is safe to overlap. It uses memmove. */
+ decodedSize = ZSTD_copyRawBlock(op, (size_t)(oend-op), ip, cBlockSize);
+ break;
+ case bt_rle :
+ decodedSize = ZSTD_setRleBlock(op, (size_t)(oBlockEnd-op), *ip, blockProperties.origSize);
+ break;
+ case bt_reserved :
+ default:
+ RETURN_ERROR(corruption_detected, "invalid block type");
+ }
+
+ if (ZSTD_isError(decodedSize)) return decodedSize;
+ if (dctx->validateChecksum)
+ XXH64_update(&dctx->xxhState, op, decodedSize);
+ if (decodedSize != 0)
+ op += decodedSize;
+ assert(ip != NULL);
+ ip += cBlockSize;
+ remainingSrcSize -= cBlockSize;
+ if (blockProperties.lastBlock) break;
+ }
+
+ if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) {
+ RETURN_ERROR_IF((U64)(op-ostart) != dctx->fParams.frameContentSize,
+ corruption_detected, "");
+ }
+ if (dctx->fParams.checksumFlag) { /* Frame content checksum verification */
+ RETURN_ERROR_IF(remainingSrcSize<4, checksum_wrong, "");
+ if (!dctx->forceIgnoreChecksum) {
+ U32 const checkCalc = (U32)XXH64_digest(&dctx->xxhState);
+ U32 checkRead;
+ checkRead = MEM_readLE32(ip);
+ RETURN_ERROR_IF(checkRead != checkCalc, checksum_wrong, "");
+ }
+ ip += 4;
+ remainingSrcSize -= 4;
+ }
+ ZSTD_DCtx_trace_end(dctx, (U64)(op-ostart), (U64)(ip-istart), /* streaming */ 0);
+ /* Allow caller to get size read */
+ DEBUGLOG(4, "ZSTD_decompressFrame: decompressed frame of size %zi, consuming %zi bytes of input", op-ostart, ip - (const BYTE*)*srcPtr);
+ *srcPtr = ip;
+ *srcSizePtr = remainingSrcSize;
+ return (size_t)(op-ostart);
+}
+
+static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict, size_t dictSize,
+ const ZSTD_DDict* ddict)
+{
+ void* const dststart = dst;
+ int moreThan1Frame = 0;
+
+ DEBUGLOG(5, "ZSTD_decompressMultiFrame");
+ assert(dict==NULL || ddict==NULL); /* either dict or ddict set, not both */
+
+ if (ddict) {
+ dict = ZSTD_DDict_dictContent(ddict);
+ dictSize = ZSTD_DDict_dictSize(ddict);
+ }
+
+ while (srcSize >= ZSTD_startingInputLength(dctx->format)) {
+
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
+ if (ZSTD_isLegacy(src, srcSize)) {
+ size_t decodedSize;
+ size_t const frameSize = ZSTD_findFrameCompressedSizeLegacy(src, srcSize);
+ if (ZSTD_isError(frameSize)) return frameSize;
+ RETURN_ERROR_IF(dctx->staticSize, memory_allocation,
+ "legacy support is not compatible with static dctx");
+
+ decodedSize = ZSTD_decompressLegacy(dst, dstCapacity, src, frameSize, dict, dictSize);
+ if (ZSTD_isError(decodedSize)) return decodedSize;
+
+ assert(decodedSize <= dstCapacity);
+ dst = (BYTE*)dst + decodedSize;
+ dstCapacity -= decodedSize;
+
+ src = (const BYTE*)src + frameSize;
+ srcSize -= frameSize;
+
+ continue;
+ }
+#endif
+
+ if (srcSize >= 4) {
+ U32 const magicNumber = MEM_readLE32(src);
+ DEBUGLOG(5, "reading magic number %08X", (unsigned)magicNumber);
+ if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
+ /* skippable frame detected : skip it */
+ size_t const skippableSize = readSkippableFrameSize(src, srcSize);
+ FORWARD_IF_ERROR(skippableSize, "invalid skippable frame");
+ assert(skippableSize <= srcSize);
+
+ src = (const BYTE *)src + skippableSize;
+ srcSize -= skippableSize;
+ continue; /* check next frame */
+ } }
+
+ if (ddict) {
+ /* we were called from ZSTD_decompress_usingDDict */
+ FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(dctx, ddict), "");
+ } else {
+ /* this will initialize correctly with no dict if dict == NULL, so
+ * use this in all cases but ddict */
+ FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize), "");
+ }
+ ZSTD_checkContinuity(dctx, dst, dstCapacity);
+
+ { const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity,
+ &src, &srcSize);
+ RETURN_ERROR_IF(
+ (ZSTD_getErrorCode(res) == ZSTD_error_prefix_unknown)
+ && (moreThan1Frame==1),
+ srcSize_wrong,
+ "At least one frame successfully completed, "
+ "but following bytes are garbage: "
+ "it's more likely to be a srcSize error, "
+ "specifying more input bytes than size of frame(s). "
+ "Note: one could be unlucky, it might be a corruption error instead, "
+ "happening right at the place where we expect zstd magic bytes. "
+ "But this is _much_ less likely than a srcSize field error.");
+ if (ZSTD_isError(res)) return res;
+ assert(res <= dstCapacity);
+ if (res != 0)
+ dst = (BYTE*)dst + res;
+ dstCapacity -= res;
+ }
+ moreThan1Frame = 1;
+ } /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */
+
+ RETURN_ERROR_IF(srcSize, srcSize_wrong, "input not entirely consumed");
+
+ return (size_t)((BYTE*)dst - (BYTE*)dststart);
+}
+
+size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict, size_t dictSize)
+{
+ return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, dict, dictSize, NULL);
+}
+
+
+static ZSTD_DDict const* ZSTD_getDDict(ZSTD_DCtx* dctx)
+{
+ switch (dctx->dictUses) {
+ default:
+ assert(0 /* Impossible */);
+ ZSTD_FALLTHROUGH;
+ case ZSTD_dont_use:
+ ZSTD_clearDict(dctx);
+ return NULL;
+ case ZSTD_use_indefinitely:
+ return dctx->ddict;
+ case ZSTD_use_once:
+ dctx->dictUses = ZSTD_dont_use;
+ return dctx->ddict;
+ }
+}
+
+size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+{
+ return ZSTD_decompress_usingDDict(dctx, dst, dstCapacity, src, srcSize, ZSTD_getDDict(dctx));
+}
+
+
+size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+{
+#if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE>=1)
+ size_t regenSize;
+ ZSTD_DCtx* const dctx = ZSTD_createDCtx_internal(ZSTD_defaultCMem);
+ RETURN_ERROR_IF(dctx==NULL, memory_allocation, "NULL pointer!");
+ regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize);
+ ZSTD_freeDCtx(dctx);
+ return regenSize;
+#else /* stack mode */
+ ZSTD_DCtx dctx;
+ ZSTD_initDCtx_internal(&dctx);
+ return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize);
+#endif
+}
+
+
+/*-**************************************
+* Advanced Streaming Decompression API
+* Bufferless and synchronous
+****************************************/
+size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; }
+
+/**
+ * Similar to ZSTD_nextSrcSizeToDecompress(), but when a block input can be streamed, we
+ * allow taking a partial block as the input. Currently only raw uncompressed blocks can
+ * be streamed.
+ *
+ * For blocks that can be streamed, this allows us to reduce the latency until we produce
+ * output, and avoid copying the input.
+ *
+ * @param inputSize - The total amount of input that the caller currently has.
+ */
+static size_t ZSTD_nextSrcSizeToDecompressWithInputSize(ZSTD_DCtx* dctx, size_t inputSize) {
+ if (!(dctx->stage == ZSTDds_decompressBlock || dctx->stage == ZSTDds_decompressLastBlock))
+ return dctx->expected;
+ if (dctx->bType != bt_raw)
+ return dctx->expected;
+ return BOUNDED(1, inputSize, dctx->expected);
+}
+
+ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) {
+ switch(dctx->stage)
+ {
+ default: /* should not happen */
+ assert(0);
+ ZSTD_FALLTHROUGH;
+ case ZSTDds_getFrameHeaderSize:
+ ZSTD_FALLTHROUGH;
+ case ZSTDds_decodeFrameHeader:
+ return ZSTDnit_frameHeader;
+ case ZSTDds_decodeBlockHeader:
+ return ZSTDnit_blockHeader;
+ case ZSTDds_decompressBlock:
+ return ZSTDnit_block;
+ case ZSTDds_decompressLastBlock:
+ return ZSTDnit_lastBlock;
+ case ZSTDds_checkChecksum:
+ return ZSTDnit_checksum;
+ case ZSTDds_decodeSkippableHeader:
+ ZSTD_FALLTHROUGH;
+ case ZSTDds_skipFrame:
+ return ZSTDnit_skippableFrame;
+ }
+}
+
+static int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; }
+
+/** ZSTD_decompressContinue() :
+ * srcSize : must be the exact nb of bytes expected (see ZSTD_nextSrcSizeToDecompress())
+ * @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity)
+ * or an error code, which can be tested using ZSTD_isError() */
+size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+{
+ DEBUGLOG(5, "ZSTD_decompressContinue (srcSize:%u)", (unsigned)srcSize);
+ /* Sanity check */
+ RETURN_ERROR_IF(srcSize != ZSTD_nextSrcSizeToDecompressWithInputSize(dctx, srcSize), srcSize_wrong, "not allowed");
+ ZSTD_checkContinuity(dctx, dst, dstCapacity);
+
+ dctx->processedCSize += srcSize;
+
+ switch (dctx->stage)
+ {
+ case ZSTDds_getFrameHeaderSize :
+ assert(src != NULL);
+ if (dctx->format == ZSTD_f_zstd1) { /* allows header */
+ assert(srcSize >= ZSTD_FRAMEIDSIZE); /* to read skippable magic number */
+ if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */
+ ZSTD_memcpy(dctx->headerBuffer, src, srcSize);
+ dctx->expected = ZSTD_SKIPPABLEHEADERSIZE - srcSize; /* remaining to load to get full skippable frame header */
+ dctx->stage = ZSTDds_decodeSkippableHeader;
+ return 0;
+ } }
+ dctx->headerSize = ZSTD_frameHeaderSize_internal(src, srcSize, dctx->format);
+ if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize;
+ ZSTD_memcpy(dctx->headerBuffer, src, srcSize);
+ dctx->expected = dctx->headerSize - srcSize;
+ dctx->stage = ZSTDds_decodeFrameHeader;
+ return 0;
+
+ case ZSTDds_decodeFrameHeader:
+ assert(src != NULL);
+ ZSTD_memcpy(dctx->headerBuffer + (dctx->headerSize - srcSize), src, srcSize);
+ FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize), "");
+ dctx->expected = ZSTD_blockHeaderSize;
+ dctx->stage = ZSTDds_decodeBlockHeader;
+ return 0;
+
+ case ZSTDds_decodeBlockHeader:
+ { blockProperties_t bp;
+ size_t const cBlockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
+ if (ZSTD_isError(cBlockSize)) return cBlockSize;
+ RETURN_ERROR_IF(cBlockSize > dctx->fParams.blockSizeMax, corruption_detected, "Block Size Exceeds Maximum");
+ dctx->expected = cBlockSize;
+ dctx->bType = bp.blockType;
+ dctx->rleSize = bp.origSize;
+ if (cBlockSize) {
+ dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock;
+ return 0;
+ }
+ /* empty block */
+ if (bp.lastBlock) {
+ if (dctx->fParams.checksumFlag) {
+ dctx->expected = 4;
+ dctx->stage = ZSTDds_checkChecksum;
+ } else {
+ dctx->expected = 0; /* end of frame */
+ dctx->stage = ZSTDds_getFrameHeaderSize;
+ }
+ } else {
+ dctx->expected = ZSTD_blockHeaderSize; /* jump to next header */
+ dctx->stage = ZSTDds_decodeBlockHeader;
+ }
+ return 0;
+ }
+
+ case ZSTDds_decompressLastBlock:
+ case ZSTDds_decompressBlock:
+ DEBUGLOG(5, "ZSTD_decompressContinue: case ZSTDds_decompressBlock");
+ { size_t rSize;
+ switch(dctx->bType)
+ {
+ case bt_compressed:
+ DEBUGLOG(5, "ZSTD_decompressContinue: case bt_compressed");
+ rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 1, is_streaming);
+ dctx->expected = 0; /* Streaming not supported */
+ break;
+ case bt_raw :
+ assert(srcSize <= dctx->expected);
+ rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize);
+ FORWARD_IF_ERROR(rSize, "ZSTD_copyRawBlock failed");
+ assert(rSize == srcSize);
+ dctx->expected -= rSize;
+ break;
+ case bt_rle :
+ rSize = ZSTD_setRleBlock(dst, dstCapacity, *(const BYTE*)src, dctx->rleSize);
+ dctx->expected = 0; /* Streaming not supported */
+ break;
+ case bt_reserved : /* should never happen */
+ default:
+ RETURN_ERROR(corruption_detected, "invalid block type");
+ }
+ FORWARD_IF_ERROR(rSize, "");
+ RETURN_ERROR_IF(rSize > dctx->fParams.blockSizeMax, corruption_detected, "Decompressed Block Size Exceeds Maximum");
+ DEBUGLOG(5, "ZSTD_decompressContinue: decoded size from block : %u", (unsigned)rSize);
+ dctx->decodedSize += rSize;
+ if (dctx->validateChecksum) XXH64_update(&dctx->xxhState, dst, rSize);
+ dctx->previousDstEnd = (char*)dst + rSize;
+
+ /* Stay on the same stage until we are finished streaming the block. */
+ if (dctx->expected > 0) {
+ return rSize;
+ }
+
+ if (dctx->stage == ZSTDds_decompressLastBlock) { /* end of frame */
+ DEBUGLOG(4, "ZSTD_decompressContinue: decoded size from frame : %u", (unsigned)dctx->decodedSize);
+ RETURN_ERROR_IF(
+ dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
+ && dctx->decodedSize != dctx->fParams.frameContentSize,
+ corruption_detected, "");
+ if (dctx->fParams.checksumFlag) { /* another round for frame checksum */
+ dctx->expected = 4;
+ dctx->stage = ZSTDds_checkChecksum;
+ } else {
+ ZSTD_DCtx_trace_end(dctx, dctx->decodedSize, dctx->processedCSize, /* streaming */ 1);
+ dctx->expected = 0; /* ends here */
+ dctx->stage = ZSTDds_getFrameHeaderSize;
+ }
+ } else {
+ dctx->stage = ZSTDds_decodeBlockHeader;
+ dctx->expected = ZSTD_blockHeaderSize;
+ }
+ return rSize;
+ }
+
+ case ZSTDds_checkChecksum:
+ assert(srcSize == 4); /* guaranteed by dctx->expected */
+ {
+ if (dctx->validateChecksum) {
+ U32 const h32 = (U32)XXH64_digest(&dctx->xxhState);
+ U32 const check32 = MEM_readLE32(src);
+ DEBUGLOG(4, "ZSTD_decompressContinue: checksum : calculated %08X :: %08X read", (unsigned)h32, (unsigned)check32);
+ RETURN_ERROR_IF(check32 != h32, checksum_wrong, "");
+ }
+ ZSTD_DCtx_trace_end(dctx, dctx->decodedSize, dctx->processedCSize, /* streaming */ 1);
+ dctx->expected = 0;
+ dctx->stage = ZSTDds_getFrameHeaderSize;
+ return 0;
+ }
+
+ case ZSTDds_decodeSkippableHeader:
+ assert(src != NULL);
+ assert(srcSize <= ZSTD_SKIPPABLEHEADERSIZE);
+ ZSTD_memcpy(dctx->headerBuffer + (ZSTD_SKIPPABLEHEADERSIZE - srcSize), src, srcSize); /* complete skippable header */
+ dctx->expected = MEM_readLE32(dctx->headerBuffer + ZSTD_FRAMEIDSIZE); /* note : dctx->expected can grow seriously large, beyond local buffer size */
+ dctx->stage = ZSTDds_skipFrame;
+ return 0;
+
+ case ZSTDds_skipFrame:
+ dctx->expected = 0;
+ dctx->stage = ZSTDds_getFrameHeaderSize;
+ return 0;
+
+ default:
+ assert(0); /* impossible */
+ RETURN_ERROR(GENERIC, "impossible to reach"); /* some compilers require default to do something */
+ }
+}
+
+
+static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
+{
+ dctx->dictEnd = dctx->previousDstEnd;
+ dctx->virtualStart = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
+ dctx->prefixStart = dict;
+ dctx->previousDstEnd = (const char*)dict + dictSize;
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ dctx->dictContentBeginForFuzzing = dctx->prefixStart;
+ dctx->dictContentEndForFuzzing = dctx->previousDstEnd;
+#endif
+ return 0;
+}
+
+/*! ZSTD_loadDEntropy() :
+ * dict : must point at beginning of a valid zstd dictionary.
+ * @return : size of entropy tables read */
+size_t
+ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
+ const void* const dict, size_t const dictSize)
+{
+ const BYTE* dictPtr = (const BYTE*)dict;
+ const BYTE* const dictEnd = dictPtr + dictSize;
+
+ RETURN_ERROR_IF(dictSize <= 8, dictionary_corrupted, "dict is too small");
+ assert(MEM_readLE32(dict) == ZSTD_MAGIC_DICTIONARY); /* dict must be valid */
+ dictPtr += 8; /* skip header = magic + dictID */
+
+ ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, OFTable) == offsetof(ZSTD_entropyDTables_t, LLTable) + sizeof(entropy->LLTable));
+ ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, MLTable) == offsetof(ZSTD_entropyDTables_t, OFTable) + sizeof(entropy->OFTable));
+ ZSTD_STATIC_ASSERT(sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable) >= HUF_DECOMPRESS_WORKSPACE_SIZE);
+ { void* const workspace = &entropy->LLTable; /* use fse tables as temporary workspace; implies fse tables are grouped together */
+ size_t const workspaceSize = sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable);
+#ifdef HUF_FORCE_DECOMPRESS_X1
+ /* in minimal huffman, we always use X1 variants */
+ size_t const hSize = HUF_readDTableX1_wksp(entropy->hufTable,
+ dictPtr, dictEnd - dictPtr,
+ workspace, workspaceSize, /* flags */ 0);
+#else
+ size_t const hSize = HUF_readDTableX2_wksp(entropy->hufTable,
+ dictPtr, (size_t)(dictEnd - dictPtr),
+ workspace, workspaceSize, /* flags */ 0);
+#endif
+ RETURN_ERROR_IF(HUF_isError(hSize), dictionary_corrupted, "");
+ dictPtr += hSize;
+ }
+
+ { short offcodeNCount[MaxOff+1];
+ unsigned offcodeMaxValue = MaxOff, offcodeLog;
+ size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, (size_t)(dictEnd-dictPtr));
+ RETURN_ERROR_IF(FSE_isError(offcodeHeaderSize), dictionary_corrupted, "");
+ RETURN_ERROR_IF(offcodeMaxValue > MaxOff, dictionary_corrupted, "");
+ RETURN_ERROR_IF(offcodeLog > OffFSELog, dictionary_corrupted, "");
+ ZSTD_buildFSETable( entropy->OFTable,
+ offcodeNCount, offcodeMaxValue,
+ OF_base, OF_bits,
+ offcodeLog,
+ entropy->workspace, sizeof(entropy->workspace),
+ /* bmi2 */0);
+ dictPtr += offcodeHeaderSize;
+ }
+
+ { short matchlengthNCount[MaxML+1];
+ unsigned matchlengthMaxValue = MaxML, matchlengthLog;
+ size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, (size_t)(dictEnd-dictPtr));
+ RETURN_ERROR_IF(FSE_isError(matchlengthHeaderSize), dictionary_corrupted, "");
+ RETURN_ERROR_IF(matchlengthMaxValue > MaxML, dictionary_corrupted, "");
+ RETURN_ERROR_IF(matchlengthLog > MLFSELog, dictionary_corrupted, "");
+ ZSTD_buildFSETable( entropy->MLTable,
+ matchlengthNCount, matchlengthMaxValue,
+ ML_base, ML_bits,
+ matchlengthLog,
+ entropy->workspace, sizeof(entropy->workspace),
+ /* bmi2 */ 0);
+ dictPtr += matchlengthHeaderSize;
+ }
+
+ { short litlengthNCount[MaxLL+1];
+ unsigned litlengthMaxValue = MaxLL, litlengthLog;
+ size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, (size_t)(dictEnd-dictPtr));
+ RETURN_ERROR_IF(FSE_isError(litlengthHeaderSize), dictionary_corrupted, "");
+ RETURN_ERROR_IF(litlengthMaxValue > MaxLL, dictionary_corrupted, "");
+ RETURN_ERROR_IF(litlengthLog > LLFSELog, dictionary_corrupted, "");
+ ZSTD_buildFSETable( entropy->LLTable,
+ litlengthNCount, litlengthMaxValue,
+ LL_base, LL_bits,
+ litlengthLog,
+ entropy->workspace, sizeof(entropy->workspace),
+ /* bmi2 */ 0);
+ dictPtr += litlengthHeaderSize;
+ }
+
+ RETURN_ERROR_IF(dictPtr+12 > dictEnd, dictionary_corrupted, "");
+ { int i;
+ size_t const dictContentSize = (size_t)(dictEnd - (dictPtr+12));
+ for (i=0; i<3; i++) {
+ U32 const rep = MEM_readLE32(dictPtr); dictPtr += 4;
+ RETURN_ERROR_IF(rep==0 || rep > dictContentSize,
+ dictionary_corrupted, "");
+ entropy->rep[i] = rep;
+ } }
+
+ return (size_t)(dictPtr - (const BYTE*)dict);
+}
+
+static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
+{
+ if (dictSize < 8) return ZSTD_refDictContent(dctx, dict, dictSize);
+ { U32 const magic = MEM_readLE32(dict);
+ if (magic != ZSTD_MAGIC_DICTIONARY) {
+ return ZSTD_refDictContent(dctx, dict, dictSize); /* pure content mode */
+ } }
+ dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
+
+ /* load entropy tables */
+ { size_t const eSize = ZSTD_loadDEntropy(&dctx->entropy, dict, dictSize);
+ RETURN_ERROR_IF(ZSTD_isError(eSize), dictionary_corrupted, "");
+ dict = (const char*)dict + eSize;
+ dictSize -= eSize;
+ }
+ dctx->litEntropy = dctx->fseEntropy = 1;
+
+ /* reference dictionary content */
+ return ZSTD_refDictContent(dctx, dict, dictSize);
+}
+
+size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx)
+{
+ assert(dctx != NULL);
+#if ZSTD_TRACE
+ dctx->traceCtx = (ZSTD_trace_decompress_begin != NULL) ? ZSTD_trace_decompress_begin(dctx) : 0;
+#endif
+ dctx->expected = ZSTD_startingInputLength(dctx->format); /* dctx->format must be properly set */
+ dctx->stage = ZSTDds_getFrameHeaderSize;
+ dctx->processedCSize = 0;
+ dctx->decodedSize = 0;
+ dctx->previousDstEnd = NULL;
+ dctx->prefixStart = NULL;
+ dctx->virtualStart = NULL;
+ dctx->dictEnd = NULL;
+ dctx->entropy.hufTable[0] = (HUF_DTable)((ZSTD_HUFFDTABLE_CAPACITY_LOG)*0x1000001); /* cover both little and big endian */
+ dctx->litEntropy = dctx->fseEntropy = 0;
+ dctx->dictID = 0;
+ dctx->bType = bt_reserved;
+ ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue));
+ ZSTD_memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue)); /* initial repcodes */
+ dctx->LLTptr = dctx->entropy.LLTable;
+ dctx->MLTptr = dctx->entropy.MLTable;
+ dctx->OFTptr = dctx->entropy.OFTable;
+ dctx->HUFptr = dctx->entropy.hufTable;
+ return 0;
+}
+
+size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
+{
+ FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) , "");
+ if (dict && dictSize)
+ RETURN_ERROR_IF(
+ ZSTD_isError(ZSTD_decompress_insertDictionary(dctx, dict, dictSize)),
+ dictionary_corrupted, "");
+ return 0;
+}
+
+
+/* ====== ZSTD_DDict ====== */
+
+size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
+{
+ DEBUGLOG(4, "ZSTD_decompressBegin_usingDDict");
+ assert(dctx != NULL);
+ if (ddict) {
+ const char* const dictStart = (const char*)ZSTD_DDict_dictContent(ddict);
+ size_t const dictSize = ZSTD_DDict_dictSize(ddict);
+ const void* const dictEnd = dictStart + dictSize;
+ dctx->ddictIsCold = (dctx->dictEnd != dictEnd);
+ DEBUGLOG(4, "DDict is %s",
+ dctx->ddictIsCold ? "~cold~" : "hot!");
+ }
+ FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) , "");
+ if (ddict) { /* NULL ddict is equivalent to no dictionary */
+ ZSTD_copyDDictParameters(dctx, ddict);
+ }
+ return 0;
+}
+
+/*! ZSTD_getDictID_fromDict() :
+ * Provides the dictID stored within dictionary.
+ * if @return == 0, the dictionary is not conformant with Zstandard specification.
+ * It can still be loaded, but as a content-only dictionary. */
+unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize)
+{
+ if (dictSize < 8) return 0;
+ if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) return 0;
+ return MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
+}
+
+/*! ZSTD_getDictID_fromFrame() :
+ * Provides the dictID required to decompress frame stored within `src`.
+ * If @return == 0, the dictID could not be decoded.
+ * This could for one of the following reasons :
+ * - The frame does not require a dictionary (most common case).
+ * - The frame was built with dictID intentionally removed.
+ * Needed dictionary is a hidden piece of information.
+ * Note : this use case also happens when using a non-conformant dictionary.
+ * - `srcSize` is too small, and as a result, frame header could not be decoded.
+ * Note : possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`.
+ * - This is not a Zstandard frame.
+ * When identifying the exact failure cause, it's possible to use
+ * ZSTD_getFrameHeader(), which will provide a more precise error code. */
+unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize)
+{
+ ZSTD_frameHeader zfp = { 0, 0, 0, ZSTD_frame, 0, 0, 0, 0, 0 };
+ size_t const hError = ZSTD_getFrameHeader(&zfp, src, srcSize);
+ if (ZSTD_isError(hError)) return 0;
+ return zfp.dictID;
+}
+
+
+/*! ZSTD_decompress_usingDDict() :
+* Decompression using a pre-digested Dictionary
+* Use dictionary without significant overhead. */
+size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const ZSTD_DDict* ddict)
+{
+ /* pass content and size in case legacy frames are encountered */
+ return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize,
+ NULL, 0,
+ ddict);
+}
+
+
+/*=====================================
+* Streaming decompression
+*====================================*/
+
+ZSTD_DStream* ZSTD_createDStream(void)
+{
+ DEBUGLOG(3, "ZSTD_createDStream");
+ return ZSTD_createDCtx_internal(ZSTD_defaultCMem);
+}
+
+ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize)
+{
+ return ZSTD_initStaticDCtx(workspace, workspaceSize);
+}
+
+ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem)
+{
+ return ZSTD_createDCtx_internal(customMem);
+}
+
+size_t ZSTD_freeDStream(ZSTD_DStream* zds)
+{
+ return ZSTD_freeDCtx(zds);
+}
+
+
+/* *** Initialization *** */
+
+size_t ZSTD_DStreamInSize(void) { return ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize; }
+size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_MAX; }
+
+size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx,
+ const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType)
+{
+ RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
+ ZSTD_clearDict(dctx);
+ if (dict && dictSize != 0) {
+ dctx->ddictLocal = ZSTD_createDDict_advanced(dict, dictSize, dictLoadMethod, dictContentType, dctx->customMem);
+ RETURN_ERROR_IF(dctx->ddictLocal == NULL, memory_allocation, "NULL pointer!");
+ dctx->ddict = dctx->ddictLocal;
+ dctx->dictUses = ZSTD_use_indefinitely;
+ }
+ return 0;
+}
+
+size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
+{
+ return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
+}
+
+size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
+{
+ return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
+}
+
+size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
+{
+ FORWARD_IF_ERROR(ZSTD_DCtx_loadDictionary_advanced(dctx, prefix, prefixSize, ZSTD_dlm_byRef, dictContentType), "");
+ dctx->dictUses = ZSTD_use_once;
+ return 0;
+}
+
+size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize)
+{
+ return ZSTD_DCtx_refPrefix_advanced(dctx, prefix, prefixSize, ZSTD_dct_rawContent);
+}
+
+
+/* ZSTD_initDStream_usingDict() :
+ * return : expected size, aka ZSTD_startingInputLength().
+ * this function cannot fail */
+size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize)
+{
+ DEBUGLOG(4, "ZSTD_initDStream_usingDict");
+ FORWARD_IF_ERROR( ZSTD_DCtx_reset(zds, ZSTD_reset_session_only) , "");
+ FORWARD_IF_ERROR( ZSTD_DCtx_loadDictionary(zds, dict, dictSize) , "");
+ return ZSTD_startingInputLength(zds->format);
+}
+
+/* note : this variant can't fail */
+size_t ZSTD_initDStream(ZSTD_DStream* zds)
+{
+ DEBUGLOG(4, "ZSTD_initDStream");
+ FORWARD_IF_ERROR(ZSTD_DCtx_reset(zds, ZSTD_reset_session_only), "");
+ FORWARD_IF_ERROR(ZSTD_DCtx_refDDict(zds, NULL), "");
+ return ZSTD_startingInputLength(zds->format);
+}
+
+/* ZSTD_initDStream_usingDDict() :
+ * ddict will just be referenced, and must outlive decompression session
+ * this function cannot fail */
+size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* dctx, const ZSTD_DDict* ddict)
+{
+ DEBUGLOG(4, "ZSTD_initDStream_usingDDict");
+ FORWARD_IF_ERROR( ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only) , "");
+ FORWARD_IF_ERROR( ZSTD_DCtx_refDDict(dctx, ddict) , "");
+ return ZSTD_startingInputLength(dctx->format);
+}
+
+/* ZSTD_resetDStream() :
+ * return : expected size, aka ZSTD_startingInputLength().
+ * this function cannot fail */
+size_t ZSTD_resetDStream(ZSTD_DStream* dctx)
+{
+ DEBUGLOG(4, "ZSTD_resetDStream");
+ FORWARD_IF_ERROR(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only), "");
+ return ZSTD_startingInputLength(dctx->format);
+}
+
+
+size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
+{
+ RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
+ ZSTD_clearDict(dctx);
+ if (ddict) {
+ dctx->ddict = ddict;
+ dctx->dictUses = ZSTD_use_indefinitely;
+ if (dctx->refMultipleDDicts == ZSTD_rmd_refMultipleDDicts) {
+ if (dctx->ddictSet == NULL) {
+ dctx->ddictSet = ZSTD_createDDictHashSet(dctx->customMem);
+ if (!dctx->ddictSet) {
+ RETURN_ERROR(memory_allocation, "Failed to allocate memory for hash set!");
+ }
+ }
+ assert(!dctx->staticSize); /* Impossible: ddictSet cannot have been allocated if static dctx */
+ FORWARD_IF_ERROR(ZSTD_DDictHashSet_addDDict(dctx->ddictSet, ddict, dctx->customMem), "");
+ }
+ }
+ return 0;
+}
+
+/* ZSTD_DCtx_setMaxWindowSize() :
+ * note : no direct equivalence in ZSTD_DCtx_setParameter,
+ * since this version sets windowSize, and the other sets windowLog */
+size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize)
+{
+ ZSTD_bounds const bounds = ZSTD_dParam_getBounds(ZSTD_d_windowLogMax);
+ size_t const min = (size_t)1 << bounds.lowerBound;
+ size_t const max = (size_t)1 << bounds.upperBound;
+ RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
+ RETURN_ERROR_IF(maxWindowSize < min, parameter_outOfBound, "");
+ RETURN_ERROR_IF(maxWindowSize > max, parameter_outOfBound, "");
+ dctx->maxWindowSize = maxWindowSize;
+ return 0;
+}
+
+size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format)
+{
+ return ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, (int)format);
+}
+
+ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam)
+{
+ ZSTD_bounds bounds = { 0, 0, 0 };
+ switch(dParam) {
+ case ZSTD_d_windowLogMax:
+ bounds.lowerBound = ZSTD_WINDOWLOG_ABSOLUTEMIN;
+ bounds.upperBound = ZSTD_WINDOWLOG_MAX;
+ return bounds;
+ case ZSTD_d_format:
+ bounds.lowerBound = (int)ZSTD_f_zstd1;
+ bounds.upperBound = (int)ZSTD_f_zstd1_magicless;
+ ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless);
+ return bounds;
+ case ZSTD_d_stableOutBuffer:
+ bounds.lowerBound = (int)ZSTD_bm_buffered;
+ bounds.upperBound = (int)ZSTD_bm_stable;
+ return bounds;
+ case ZSTD_d_forceIgnoreChecksum:
+ bounds.lowerBound = (int)ZSTD_d_validateChecksum;
+ bounds.upperBound = (int)ZSTD_d_ignoreChecksum;
+ return bounds;
+ case ZSTD_d_refMultipleDDicts:
+ bounds.lowerBound = (int)ZSTD_rmd_refSingleDDict;
+ bounds.upperBound = (int)ZSTD_rmd_refMultipleDDicts;
+ return bounds;
+ case ZSTD_d_disableHuffmanAssembly:
+ bounds.lowerBound = 0;
+ bounds.upperBound = 1;
+ return bounds;
+
+ default:;
+ }
+ bounds.error = ERROR(parameter_unsupported);
+ return bounds;
+}
+
+/* ZSTD_dParam_withinBounds:
+ * @return 1 if value is within dParam bounds,
+ * 0 otherwise */
+static int ZSTD_dParam_withinBounds(ZSTD_dParameter dParam, int value)
+{
+ ZSTD_bounds const bounds = ZSTD_dParam_getBounds(dParam);
+ if (ZSTD_isError(bounds.error)) return 0;
+ if (value < bounds.lowerBound) return 0;
+ if (value > bounds.upperBound) return 0;
+ return 1;
+}
+
+#define CHECK_DBOUNDS(p,v) { \
+ RETURN_ERROR_IF(!ZSTD_dParam_withinBounds(p, v), parameter_outOfBound, ""); \
+}
+
+size_t ZSTD_DCtx_getParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int* value)
+{
+ switch (param) {
+ case ZSTD_d_windowLogMax:
+ *value = (int)ZSTD_highbit32((U32)dctx->maxWindowSize);
+ return 0;
+ case ZSTD_d_format:
+ *value = (int)dctx->format;
+ return 0;
+ case ZSTD_d_stableOutBuffer:
+ *value = (int)dctx->outBufferMode;
+ return 0;
+ case ZSTD_d_forceIgnoreChecksum:
+ *value = (int)dctx->forceIgnoreChecksum;
+ return 0;
+ case ZSTD_d_refMultipleDDicts:
+ *value = (int)dctx->refMultipleDDicts;
+ return 0;
+ case ZSTD_d_disableHuffmanAssembly:
+ *value = (int)dctx->disableHufAsm;
+ return 0;
+ default:;
+ }
+ RETURN_ERROR(parameter_unsupported, "");
+}
+
+size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter dParam, int value)
+{
+ RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
+ switch(dParam) {
+ case ZSTD_d_windowLogMax:
+ if (value == 0) value = ZSTD_WINDOWLOG_LIMIT_DEFAULT;
+ CHECK_DBOUNDS(ZSTD_d_windowLogMax, value);
+ dctx->maxWindowSize = ((size_t)1) << value;
+ return 0;
+ case ZSTD_d_format:
+ CHECK_DBOUNDS(ZSTD_d_format, value);
+ dctx->format = (ZSTD_format_e)value;
+ return 0;
+ case ZSTD_d_stableOutBuffer:
+ CHECK_DBOUNDS(ZSTD_d_stableOutBuffer, value);
+ dctx->outBufferMode = (ZSTD_bufferMode_e)value;
+ return 0;
+ case ZSTD_d_forceIgnoreChecksum:
+ CHECK_DBOUNDS(ZSTD_d_forceIgnoreChecksum, value);
+ dctx->forceIgnoreChecksum = (ZSTD_forceIgnoreChecksum_e)value;
+ return 0;
+ case ZSTD_d_refMultipleDDicts:
+ CHECK_DBOUNDS(ZSTD_d_refMultipleDDicts, value);
+ if (dctx->staticSize != 0) {
+ RETURN_ERROR(parameter_unsupported, "Static dctx does not support multiple DDicts!");
+ }
+ dctx->refMultipleDDicts = (ZSTD_refMultipleDDicts_e)value;
+ return 0;
+ case ZSTD_d_disableHuffmanAssembly:
+ CHECK_DBOUNDS(ZSTD_d_disableHuffmanAssembly, value);
+ dctx->disableHufAsm = value != 0;
+ return 0;
+ default:;
+ }
+ RETURN_ERROR(parameter_unsupported, "");
+}
+
+size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset)
+{
+ if ( (reset == ZSTD_reset_session_only)
+ || (reset == ZSTD_reset_session_and_parameters) ) {
+ dctx->streamStage = zdss_init;
+ dctx->noForwardProgress = 0;
+ }
+ if ( (reset == ZSTD_reset_parameters)
+ || (reset == ZSTD_reset_session_and_parameters) ) {
+ RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
+ ZSTD_clearDict(dctx);
+ ZSTD_DCtx_resetParameters(dctx);
+ }
+ return 0;
+}
+
+
+size_t ZSTD_sizeof_DStream(const ZSTD_DStream* dctx)
+{
+ return ZSTD_sizeof_DCtx(dctx);
+}
+
+size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize)
+{
+ size_t const blockSize = (size_t) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
+ /* space is needed to store the litbuffer after the output of a given block without stomping the extDict of a previous run, as well as to cover both windows against wildcopy*/
+ unsigned long long const neededRBSize = windowSize + blockSize + ZSTD_BLOCKSIZE_MAX + (WILDCOPY_OVERLENGTH * 2);
+ unsigned long long const neededSize = MIN(frameContentSize, neededRBSize);
+ size_t const minRBSize = (size_t) neededSize;
+ RETURN_ERROR_IF((unsigned long long)minRBSize != neededSize,
+ frameParameter_windowTooLarge, "");
+ return minRBSize;
+}
+
+size_t ZSTD_estimateDStreamSize(size_t windowSize)
+{
+ size_t const blockSize = MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
+ size_t const inBuffSize = blockSize; /* no block can be larger */
+ size_t const outBuffSize = ZSTD_decodingBufferSize_min(windowSize, ZSTD_CONTENTSIZE_UNKNOWN);
+ return ZSTD_estimateDCtxSize() + inBuffSize + outBuffSize;
+}
+
+size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize)
+{
+ U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX; /* note : should be user-selectable, but requires an additional parameter (or a dctx) */
+ ZSTD_frameHeader zfh;
+ size_t const err = ZSTD_getFrameHeader(&zfh, src, srcSize);
+ if (ZSTD_isError(err)) return err;
+ RETURN_ERROR_IF(err>0, srcSize_wrong, "");
+ RETURN_ERROR_IF(zfh.windowSize > windowSizeMax,
+ frameParameter_windowTooLarge, "");
+ return ZSTD_estimateDStreamSize((size_t)zfh.windowSize);
+}
+
+
+/* ***** Decompression ***** */
+
+static int ZSTD_DCtx_isOverflow(ZSTD_DStream* zds, size_t const neededInBuffSize, size_t const neededOutBuffSize)
+{
+ return (zds->inBuffSize + zds->outBuffSize) >= (neededInBuffSize + neededOutBuffSize) * ZSTD_WORKSPACETOOLARGE_FACTOR;
+}
+
+static void ZSTD_DCtx_updateOversizedDuration(ZSTD_DStream* zds, size_t const neededInBuffSize, size_t const neededOutBuffSize)
+{
+ if (ZSTD_DCtx_isOverflow(zds, neededInBuffSize, neededOutBuffSize))
+ zds->oversizedDuration++;
+ else
+ zds->oversizedDuration = 0;
+}
+
+static int ZSTD_DCtx_isOversizedTooLong(ZSTD_DStream* zds)
+{
+ return zds->oversizedDuration >= ZSTD_WORKSPACETOOLARGE_MAXDURATION;
+}
+
+/* Checks that the output buffer hasn't changed if ZSTD_obm_stable is used. */
+static size_t ZSTD_checkOutBuffer(ZSTD_DStream const* zds, ZSTD_outBuffer const* output)
+{
+ ZSTD_outBuffer const expect = zds->expectedOutBuffer;
+ /* No requirement when ZSTD_obm_stable is not enabled. */
+ if (zds->outBufferMode != ZSTD_bm_stable)
+ return 0;
+ /* Any buffer is allowed in zdss_init, this must be the same for every other call until
+ * the context is reset.
+ */
+ if (zds->streamStage == zdss_init)
+ return 0;
+ /* The buffer must match our expectation exactly. */
+ if (expect.dst == output->dst && expect.pos == output->pos && expect.size == output->size)
+ return 0;
+ RETURN_ERROR(dstBuffer_wrong, "ZSTD_d_stableOutBuffer enabled but output differs!");
+}
+
+/* Calls ZSTD_decompressContinue() with the right parameters for ZSTD_decompressStream()
+ * and updates the stage and the output buffer state. This call is extracted so it can be
+ * used both when reading directly from the ZSTD_inBuffer, and in buffered input mode.
+ * NOTE: You must break after calling this function since the streamStage is modified.
+ */
+static size_t ZSTD_decompressContinueStream(
+ ZSTD_DStream* zds, char** op, char* oend,
+ void const* src, size_t srcSize) {
+ int const isSkipFrame = ZSTD_isSkipFrame(zds);
+ if (zds->outBufferMode == ZSTD_bm_buffered) {
+ size_t const dstSize = isSkipFrame ? 0 : zds->outBuffSize - zds->outStart;
+ size_t const decodedSize = ZSTD_decompressContinue(zds,
+ zds->outBuff + zds->outStart, dstSize, src, srcSize);
+ FORWARD_IF_ERROR(decodedSize, "");
+ if (!decodedSize && !isSkipFrame) {
+ zds->streamStage = zdss_read;
+ } else {
+ zds->outEnd = zds->outStart + decodedSize;
+ zds->streamStage = zdss_flush;
+ }
+ } else {
+ /* Write directly into the output buffer */
+ size_t const dstSize = isSkipFrame ? 0 : (size_t)(oend - *op);
+ size_t const decodedSize = ZSTD_decompressContinue(zds, *op, dstSize, src, srcSize);
+ FORWARD_IF_ERROR(decodedSize, "");
+ *op += decodedSize;
+ /* Flushing is not needed. */
+ zds->streamStage = zdss_read;
+ assert(*op <= oend);
+ assert(zds->outBufferMode == ZSTD_bm_stable);
+ }
+ return 0;
+}
+
+size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
+{
+ const char* const src = (const char*)input->src;
+ const char* const istart = input->pos != 0 ? src + input->pos : src;
+ const char* const iend = input->size != 0 ? src + input->size : src;
+ const char* ip = istart;
+ char* const dst = (char*)output->dst;
+ char* const ostart = output->pos != 0 ? dst + output->pos : dst;
+ char* const oend = output->size != 0 ? dst + output->size : dst;
+ char* op = ostart;
+ U32 someMoreWork = 1;
+
+ DEBUGLOG(5, "ZSTD_decompressStream");
+ RETURN_ERROR_IF(
+ input->pos > input->size,
+ srcSize_wrong,
+ "forbidden. in: pos: %u vs size: %u",
+ (U32)input->pos, (U32)input->size);
+ RETURN_ERROR_IF(
+ output->pos > output->size,
+ dstSize_tooSmall,
+ "forbidden. out: pos: %u vs size: %u",
+ (U32)output->pos, (U32)output->size);
+ DEBUGLOG(5, "input size : %u", (U32)(input->size - input->pos));
+ FORWARD_IF_ERROR(ZSTD_checkOutBuffer(zds, output), "");
+
+ while (someMoreWork) {
+ switch(zds->streamStage)
+ {
+ case zdss_init :
+ DEBUGLOG(5, "stage zdss_init => transparent reset ");
+ zds->streamStage = zdss_loadHeader;
+ zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+ zds->legacyVersion = 0;
+#endif
+ zds->hostageByte = 0;
+ zds->expectedOutBuffer = *output;
+ ZSTD_FALLTHROUGH;
+
+ case zdss_loadHeader :
+ DEBUGLOG(5, "stage zdss_loadHeader (srcSize : %u)", (U32)(iend - ip));
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+ if (zds->legacyVersion) {
+ RETURN_ERROR_IF(zds->staticSize, memory_allocation,
+ "legacy support is incompatible with static dctx");
+ { size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
+ if (hint==0) zds->streamStage = zdss_init;
+ return hint;
+ } }
+#endif
+ { size_t const hSize = ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format);
+ if (zds->refMultipleDDicts && zds->ddictSet) {
+ ZSTD_DCtx_selectFrameDDict(zds);
+ }
+ if (ZSTD_isError(hSize)) {
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+ U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart);
+ if (legacyVersion) {
+ ZSTD_DDict const* const ddict = ZSTD_getDDict(zds);
+ const void* const dict = ddict ? ZSTD_DDict_dictContent(ddict) : NULL;
+ size_t const dictSize = ddict ? ZSTD_DDict_dictSize(ddict) : 0;
+ DEBUGLOG(5, "ZSTD_decompressStream: detected legacy version v0.%u", legacyVersion);
+ RETURN_ERROR_IF(zds->staticSize, memory_allocation,
+ "legacy support is incompatible with static dctx");
+ FORWARD_IF_ERROR(ZSTD_initLegacyStream(&zds->legacyContext,
+ zds->previousLegacyVersion, legacyVersion,
+ dict, dictSize), "");
+ zds->legacyVersion = zds->previousLegacyVersion = legacyVersion;
+ { size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, legacyVersion, output, input);
+ if (hint==0) zds->streamStage = zdss_init; /* or stay in stage zdss_loadHeader */
+ return hint;
+ } }
+#endif
+ return hSize; /* error */
+ }
+ if (hSize != 0) { /* need more input */
+ size_t const toLoad = hSize - zds->lhSize; /* if hSize!=0, hSize > zds->lhSize */
+ size_t const remainingInput = (size_t)(iend-ip);
+ assert(iend >= ip);
+ if (toLoad > remainingInput) { /* not enough input to load full header */
+ if (remainingInput > 0) {
+ ZSTD_memcpy(zds->headerBuffer + zds->lhSize, ip, remainingInput);
+ zds->lhSize += remainingInput;
+ }
+ input->pos = input->size;
+ /* check first few bytes */
+ FORWARD_IF_ERROR(
+ ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format),
+ "First few bytes detected incorrect" );
+ /* return hint input size */
+ return (MAX((size_t)ZSTD_FRAMEHEADERSIZE_MIN(zds->format), hSize) - zds->lhSize) + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */
+ }
+ assert(ip != NULL);
+ ZSTD_memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad;
+ break;
+ } }
+
+ /* check for single-pass mode opportunity */
+ if (zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
+ && zds->fParams.frameType != ZSTD_skippableFrame
+ && (U64)(size_t)(oend-op) >= zds->fParams.frameContentSize) {
+ size_t const cSize = ZSTD_findFrameCompressedSize(istart, (size_t)(iend-istart));
+ if (cSize <= (size_t)(iend-istart)) {
+ /* shortcut : using single-pass mode */
+ size_t const decompressedSize = ZSTD_decompress_usingDDict(zds, op, (size_t)(oend-op), istart, cSize, ZSTD_getDDict(zds));
+ if (ZSTD_isError(decompressedSize)) return decompressedSize;
+ DEBUGLOG(4, "shortcut to single-pass ZSTD_decompress_usingDDict()")
+ assert(istart != NULL);
+ ip = istart + cSize;
+ op = op ? op + decompressedSize : op; /* can occur if frameContentSize = 0 (empty frame) */
+ zds->expected = 0;
+ zds->streamStage = zdss_init;
+ someMoreWork = 0;
+ break;
+ } }
+
+ /* Check output buffer is large enough for ZSTD_odm_stable. */
+ if (zds->outBufferMode == ZSTD_bm_stable
+ && zds->fParams.frameType != ZSTD_skippableFrame
+ && zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
+ && (U64)(size_t)(oend-op) < zds->fParams.frameContentSize) {
+ RETURN_ERROR(dstSize_tooSmall, "ZSTD_obm_stable passed but ZSTD_outBuffer is too small");
+ }
+
+ /* Consume header (see ZSTDds_decodeFrameHeader) */
+ DEBUGLOG(4, "Consume header");
+ FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(zds, ZSTD_getDDict(zds)), "");
+
+ if ((MEM_readLE32(zds->headerBuffer) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */
+ zds->expected = MEM_readLE32(zds->headerBuffer + ZSTD_FRAMEIDSIZE);
+ zds->stage = ZSTDds_skipFrame;
+ } else {
+ FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(zds, zds->headerBuffer, zds->lhSize), "");
+ zds->expected = ZSTD_blockHeaderSize;
+ zds->stage = ZSTDds_decodeBlockHeader;
+ }
+
+ /* control buffer memory usage */
+ DEBUGLOG(4, "Control max memory usage (%u KB <= max %u KB)",
+ (U32)(zds->fParams.windowSize >>10),
+ (U32)(zds->maxWindowSize >> 10) );
+ zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN);
+ RETURN_ERROR_IF(zds->fParams.windowSize > zds->maxWindowSize,
+ frameParameter_windowTooLarge, "");
+
+ /* Adapt buffer sizes to frame header instructions */
+ { size_t const neededInBuffSize = MAX(zds->fParams.blockSizeMax, 4 /* frame checksum */);
+ size_t const neededOutBuffSize = zds->outBufferMode == ZSTD_bm_buffered
+ ? ZSTD_decodingBufferSize_min(zds->fParams.windowSize, zds->fParams.frameContentSize)
+ : 0;
+
+ ZSTD_DCtx_updateOversizedDuration(zds, neededInBuffSize, neededOutBuffSize);
+
+ { int const tooSmall = (zds->inBuffSize < neededInBuffSize) || (zds->outBuffSize < neededOutBuffSize);
+ int const tooLarge = ZSTD_DCtx_isOversizedTooLong(zds);
+
+ if (tooSmall || tooLarge) {
+ size_t const bufferSize = neededInBuffSize + neededOutBuffSize;
+ DEBUGLOG(4, "inBuff : from %u to %u",
+ (U32)zds->inBuffSize, (U32)neededInBuffSize);
+ DEBUGLOG(4, "outBuff : from %u to %u",
+ (U32)zds->outBuffSize, (U32)neededOutBuffSize);
+ if (zds->staticSize) { /* static DCtx */
+ DEBUGLOG(4, "staticSize : %u", (U32)zds->staticSize);
+ assert(zds->staticSize >= sizeof(ZSTD_DCtx)); /* controlled at init */
+ RETURN_ERROR_IF(
+ bufferSize > zds->staticSize - sizeof(ZSTD_DCtx),
+ memory_allocation, "");
+ } else {
+ ZSTD_customFree(zds->inBuff, zds->customMem);
+ zds->inBuffSize = 0;
+ zds->outBuffSize = 0;
+ zds->inBuff = (char*)ZSTD_customMalloc(bufferSize, zds->customMem);
+ RETURN_ERROR_IF(zds->inBuff == NULL, memory_allocation, "");
+ }
+ zds->inBuffSize = neededInBuffSize;
+ zds->outBuff = zds->inBuff + zds->inBuffSize;
+ zds->outBuffSize = neededOutBuffSize;
+ } } }
+ zds->streamStage = zdss_read;
+ ZSTD_FALLTHROUGH;
+
+ case zdss_read:
+ DEBUGLOG(5, "stage zdss_read");
+ { size_t const neededInSize = ZSTD_nextSrcSizeToDecompressWithInputSize(zds, (size_t)(iend - ip));
+ DEBUGLOG(5, "neededInSize = %u", (U32)neededInSize);
+ if (neededInSize==0) { /* end of frame */
+ zds->streamStage = zdss_init;
+ someMoreWork = 0;
+ break;
+ }
+ if ((size_t)(iend-ip) >= neededInSize) { /* decode directly from src */
+ FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, ip, neededInSize), "");
+ assert(ip != NULL);
+ ip += neededInSize;
+ /* Function modifies the stage so we must break */
+ break;
+ } }
+ if (ip==iend) { someMoreWork = 0; break; } /* no more input */
+ zds->streamStage = zdss_load;
+ ZSTD_FALLTHROUGH;
+
+ case zdss_load:
+ { size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds);
+ size_t const toLoad = neededInSize - zds->inPos;
+ int const isSkipFrame = ZSTD_isSkipFrame(zds);
+ size_t loadedSize;
+ /* At this point we shouldn't be decompressing a block that we can stream. */
+ assert(neededInSize == ZSTD_nextSrcSizeToDecompressWithInputSize(zds, (size_t)(iend - ip)));
+ if (isSkipFrame) {
+ loadedSize = MIN(toLoad, (size_t)(iend-ip));
+ } else {
+ RETURN_ERROR_IF(toLoad > zds->inBuffSize - zds->inPos,
+ corruption_detected,
+ "should never happen");
+ loadedSize = ZSTD_limitCopy(zds->inBuff + zds->inPos, toLoad, ip, (size_t)(iend-ip));
+ }
+ if (loadedSize != 0) {
+ /* ip may be NULL */
+ ip += loadedSize;
+ zds->inPos += loadedSize;
+ }
+ if (loadedSize < toLoad) { someMoreWork = 0; break; } /* not enough input, wait for more */
+
+ /* decode loaded input */
+ zds->inPos = 0; /* input is consumed */
+ FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, zds->inBuff, neededInSize), "");
+ /* Function modifies the stage so we must break */
+ break;
+ }
+ case zdss_flush:
+ {
+ size_t const toFlushSize = zds->outEnd - zds->outStart;
+ size_t const flushedSize = ZSTD_limitCopy(op, (size_t)(oend-op), zds->outBuff + zds->outStart, toFlushSize);
+
+ op = op ? op + flushedSize : op;
+
+ zds->outStart += flushedSize;
+ if (flushedSize == toFlushSize) { /* flush completed */
+ zds->streamStage = zdss_read;
+ if ( (zds->outBuffSize < zds->fParams.frameContentSize)
+ && (zds->outStart + zds->fParams.blockSizeMax > zds->outBuffSize) ) {
+ DEBUGLOG(5, "restart filling outBuff from beginning (left:%i, needed:%u)",
+ (int)(zds->outBuffSize - zds->outStart),
+ (U32)zds->fParams.blockSizeMax);
+ zds->outStart = zds->outEnd = 0;
+ }
+ break;
+ } }
+ /* cannot complete flush */
+ someMoreWork = 0;
+ break;
+
+ default:
+ assert(0); /* impossible */
+ RETURN_ERROR(GENERIC, "impossible to reach"); /* some compilers require default to do something */
+ } }
+
+ /* result */
+ input->pos = (size_t)(ip - (const char*)(input->src));
+ output->pos = (size_t)(op - (char*)(output->dst));
+
+ /* Update the expected output buffer for ZSTD_obm_stable. */
+ zds->expectedOutBuffer = *output;
+
+ if ((ip==istart) && (op==ostart)) { /* no forward progress */
+ zds->noForwardProgress ++;
+ if (zds->noForwardProgress >= ZSTD_NO_FORWARD_PROGRESS_MAX) {
+ RETURN_ERROR_IF(op==oend, noForwardProgress_destFull, "");
+ RETURN_ERROR_IF(ip==iend, noForwardProgress_inputEmpty, "");
+ assert(0);
+ }
+ } else {
+ zds->noForwardProgress = 0;
+ }
+ { size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds);
+ if (!nextSrcSizeHint) { /* frame fully decoded */
+ if (zds->outEnd == zds->outStart) { /* output fully flushed */
+ if (zds->hostageByte) {
+ if (input->pos >= input->size) {
+ /* can't release hostage (not present) */
+ zds->streamStage = zdss_read;
+ return 1;
+ }
+ input->pos++; /* release hostage */
+ } /* zds->hostageByte */
+ return 0;
+ } /* zds->outEnd == zds->outStart */
+ if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */
+ input->pos--; /* note : pos > 0, otherwise, impossible to finish reading last block */
+ zds->hostageByte=1;
+ }
+ return 1;
+ } /* nextSrcSizeHint==0 */
+ nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds) == ZSTDnit_block); /* preload header of next block */
+ assert(zds->inPos <= nextSrcSizeHint);
+ nextSrcSizeHint -= zds->inPos; /* part already loaded*/
+ return nextSrcSizeHint;
+ }
+}
+
+size_t ZSTD_decompressStream_simpleArgs (
+ ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity, size_t* dstPos,
+ const void* src, size_t srcSize, size_t* srcPos)
+{
+ ZSTD_outBuffer output;
+ ZSTD_inBuffer input;
+ output.dst = dst;
+ output.size = dstCapacity;
+ output.pos = *dstPos;
+ input.src = src;
+ input.size = srcSize;
+ input.pos = *srcPos;
+ { size_t const cErr = ZSTD_decompressStream(dctx, &output, &input);
+ *dstPos = output.pos;
+ *srcPos = input.pos;
+ return cErr;
+ }
+}
notaz.gp2x.de / pcsx_rearmed.git / blobdiff