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first version supporting legacy streams (transparent decoding)

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This commit is contained in:
Yann Collet
2016-08-28 07:43:34 -07:00
parent bbd5bb75a6
commit 4bf317dd00
5 changed files with 215 additions and 31 deletions
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lib/decompress/zstd_decompress.c
+45 -5
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@@ -1308,8 +1308,8 @@ ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
if (ZSTD_isLegacy(src, srcSize)) return ZSTD_decompressLegacy(dst, dstCapacity, src, srcSize, ddict->dict, ddict->dictSize);
#endif
return ZSTD_decompress_usingPreparedDCtx(dctx, ddict->refContext,
dst, dstCapacity,
src, srcSize);
dst, dstCapacity,
src, srcSize);
}
@@ -1337,6 +1337,11 @@ struct ZSTD_DStream_s {
BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
size_t lhSize;
ZSTD_customMem customMem;
void* dictContent;
size_t dictSize;
const void* dictSource;
void* legacyContext;
U32 legacyVersion;
}; /* typedef'd to ZSTD_DStream within "zstd.h" */
@@ -1372,6 +1377,13 @@ size_t ZSTD_freeDStream(ZSTD_DStream* zds)
ZSTD_freeDCtx(zds->zd);
if (zds->inBuff) zds->customMem.customFree(zds->customMem.opaque, zds->inBuff);
if (zds->outBuff) zds->customMem.customFree(zds->customMem.opaque, zds->outBuff);
if (zds->dictContent) zds->customMem.customFree(zds->customMem.opaque, zds->dictContent);
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
if (zds->legacyContext) {
ZSTD_freeLegacyStreamContext(zds->legacyContext, zds->legacyVersion);
zds->legacyContext = NULL;
}
#endif
zds->customMem.customFree(zds->customMem.opaque, zds);
return 0;
}
@@ -1386,7 +1398,18 @@ size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t di
{
zds->stage = zdss_loadHeader;
zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
return ZSTD_decompressBegin_usingDict(zds->zd, dict, dictSize);
if ((dict != zds->dictSource) || (dictSize != zds->dictSize)) { /* new dictionary */
if (dictSize > zds->dictSize) {
if (zds->dictContent) zds->customMem.customFree(zds->customMem.opaque, zds->dictContent);
zds->dictContent = zds->customMem.customAlloc(zds->customMem.opaque, dictSize);
if (zds->dictContent == NULL) return ERROR(memory_allocation);
}
memcpy(zds->dictContent, dict, dictSize);
zds->dictSize = dictSize;
}
if (zds->legacyContext) zds->customMem.customFree(zds->customMem.opaque, zds->dictContent); /* legacy restarts from scratch on each call, to detect restart */
zds->legacyVersion = 0;
return 0;
}
size_t ZSTD_initDStream(ZSTD_DStream* zds)
@@ -1432,6 +1455,11 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
char* op = ostart;
U32 someMoreWork = 1;
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
if (zds->legacyVersion)
return ZSTD_decompressLegacyStream(&zds->legacyContext, zds->legacyVersion, output, input);
#endif
while (someMoreWork) {
switch(zds->stage)
{
@@ -1439,8 +1467,19 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
return ERROR(init_missing);
case zdss_loadHeader :
{ size_t const hSize = ZSTD_getFrameParams(&(zds->fParams), zds->headerBuffer, zds->lhSize);
if (ZSTD_isError(hSize)) return hSize;
{ size_t const hSize = ZSTD_getFrameParams(&zds->fParams, zds->headerBuffer, zds->lhSize);
if (ZSTD_isError(hSize))
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
{ U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart)
if (legacyVersion) {
zds->legacyVersion = legacyVersion;
return ZSTD_decompressLegacyStream(&zds->legacyContext, zds->legacyVersion, output, input);
} else {
return hSize; /* error */
} }
#else
return hSize;
#endif
if (hSize != 0) { /* need more input */
size_t const toLoad = hSize - zds->lhSize; /* if hSize!=0, hSize > zds->lhSize */
if (toLoad > (size_t)(iend-ip)) { /* not enough input to load full header */
@@ -1454,6 +1493,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
} }
/* Consume header */
ZSTD_decompressBegin_usingDict(zds->zd, zds->dictContent, zds->dictSize);
{ size_t const h1Size = ZSTD_nextSrcSizeToDecompress(zds->zd); /* == ZSTD_frameHeaderSize_min */
size_t const h1Result = ZSTD_decompressContinue(zds->zd, NULL, 0, zds->headerBuffer, h1Size);
if (ZSTD_isError(h1Result)) return h1Result; /* should not happen : already checked */