in cdk/extra/zstd/lib/decompress/zstd_decompress.c [2035:2335]
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;
}
}