ddidderr/zstd-rs
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changed streaming decoder behavior : now, when all compressed frame is consumed, it means decompression is completed, with regenerated data fully flushed.

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This commit is contained in:
Yann Collet
2016-09-09 16:44:16 +02:00
parent b94fcc8d8a
commit b3060f7a9e
4 changed files with 33 additions and 18 deletions
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lib/decompress/zstd_decompress.c
+22 -7
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@@ -1286,6 +1286,7 @@ struct ZSTD_DStream_s {
void* legacyContext;
U32 previousLegacyVersion;
U32 legacyVersion;
U32 hostageByte;
}; /* typedef'd to ZSTD_DStream within "zstd.h" */
@@ -1349,6 +1350,7 @@ size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t di
zds->dictSize = dictSize;
}
zds->legacyVersion = 0;
zds->hostageByte = 0;
return ZSTD_frameHeaderSize_prefix;
}
@@ -1371,11 +1373,11 @@ size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds,
size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds)
{
return sizeof(*zds) + ZSTD_sizeof_DCtx(zds->zd) + zds->inBuffSize + zds->outBuffSize;
return sizeof(*zds) + ZSTD_sizeof_DCtx(zds->zd) + zds->inBuffSize + zds->outBuffSize + zds->dictSize;
}
/* *** Decompression *** */
/* ***** Decompression ***** */
MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
@@ -1445,7 +1447,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN);
if (zds->fParams.windowSize > zds->maxWindowSize) return ERROR(frameParameter_unsupported);
/* Frame header instruct buffer sizes */
/* Adapt buffer sizes to frame header instructions */
{ size_t const blockSize = MIN(zds->fParams.windowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX);
size_t const neededOutSize = zds->fParams.windowSize + blockSize;
zds->blockSize = blockSize;
@@ -1479,7 +1481,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
if (ZSTD_isError(decodedSize)) return decodedSize;
ip += neededInSize;
if (!decodedSize && !isSkipFrame) break; /* this was just a header */
zds->outEnd = zds->outStart + decodedSize;
zds->outEnd = zds->outStart + decodedSize;
zds->stage = zdss_flush;
break;
}
@@ -1522,7 +1524,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
zds->outStart = zds->outEnd = 0;
break;
}
/* cannot flush everything */
/* cannot complete flush */
someMoreWork = 0;
break;
}
@@ -1533,8 +1535,21 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
input->pos += (size_t)(ip-istart);
output->pos += (size_t)(op-ostart);
{ size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds->zd);
if (!nextSrcSizeHint) return (zds->outEnd != zds->outStart); /* return 0 only if fully flushed too */
nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds->zd) == ZSTDnit_block);
if (!nextSrcSizeHint) { /* frame fully decoded */
if (zds->outEnd == zds->outStart) { /* output fully flushed */
if (zds->hostageByte) {
if (input->pos >= input->size) { zds->stage = zdss_read; return 1; } /* can't release hostage (not present) */
input->pos++; /* release hostage */
}
return 0;
}
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 += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds->zd) == ZSTDnit_block); /* preload header of next block */
if (zds->inPos > nextSrcSizeHint) return ERROR(GENERIC); /* should never happen */
nextSrcSizeHint -= zds->inPos; /* already loaded*/
return nextSrcSizeHint;