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Added : zstd buffered API

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This commit is contained in:
Yann Collet
2015-11-25 14:42:45 +01:00
parent c36521571e
commit 88fcd2916e
14 changed files with 1177 additions and 500 deletions
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lib/zstd_decompress.c
+136 -64
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@@ -120,6 +120,9 @@ const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }
/* *************************************************************
* Context management
***************************************************************/
typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock } ZSTD_dStage;
struct ZSTD_DCtx_s
{
U32 LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
@@ -130,18 +133,21 @@ struct ZSTD_DCtx_s
void* vBase;
void* dictEnd;
size_t expected;
size_t headerSize;
ZSTD_parameters params;
blockType_t bType;
U32 phase;
ZSTD_dStage stage;
const BYTE* litPtr;
size_t litBufSize;
size_t litSize;
BYTE litBuffer[BLOCKSIZE + 8 /* margin for wildcopy */];
BYTE headerBuffer[ZSTD_frameHeaderSize_max];
}; /* typedef'd to ZSTD_Dctx within "zstd_static.h" */
size_t ZSTD_resetDCtx(ZSTD_DCtx* dctx)
{
dctx->expected = ZSTD_frameHeaderSize;
dctx->phase = 0;
dctx->expected = ZSTD_frameHeaderSize_min;
dctx->stage = ZSTDds_getFrameHeaderSize;
dctx->previousDstEnd = NULL;
dctx->base = NULL;
dctx->vBase = NULL;
@@ -167,6 +173,45 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
/* *************************************************************
* Decompression section
***************************************************************/
/** ZSTD_decodeFrameHeader_Part1
* decode the 1st part of the Frame Header, which tells Frame Header size.
* srcSize must be == ZSTD_frameHeaderSize_min
* @return : the full size of the Frame Header */
static size_t ZSTD_decodeFrameHeader_Part1(ZSTD_DCtx* zc, const void* src, size_t srcSize)
{
U32 magicNumber;
if (srcSize != ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong);
magicNumber = MEM_readLE32(src);
if (magicNumber != ZSTD_MAGICNUMBER) return ERROR(prefix_unknown);
zc->headerSize = ZSTD_frameHeaderSize_min;
return zc->headerSize;
}
/** ZSTD_decodeFrameHeader_Part2
* decode the full Frame Header
* srcSize must be the size provided by ZSTD_decodeFrameHeader_Part1
* @return : 0, or an error code, which can be tested using ZSTD_isError() */
static size_t ZSTD_decodeFrameHeader_Part2(ZSTD_DCtx* zc, const void* src, size_t srcSize)
{
const BYTE* ip = (const BYTE*)src;
if (srcSize != zc->headerSize) return ERROR(srcSize_wrong);
memset(&(zc->params), 0, sizeof(zc->params));
zc->params.windowLog = ip[4] + ZSTD_WINDOWLOG_ABSOLUTEMIN;
return 0;
}
size_t ZSTD_getFrameParams(ZSTD_parameters* params, const void* src, size_t srcSize)
{
U32 magicNumber;
if (srcSize < ZSTD_frameHeaderSize_min) return ZSTD_frameHeaderSize_max;
magicNumber = MEM_readLE32(src);
if (magicNumber != ZSTD_MAGICNUMBER) return ERROR(prefix_unknown);
memset(params, 0, sizeof(*params));
params->windowLog = ((const BYTE*)src)[4] + ZSTD_WINDOWLOG_ABSOLUTEMIN;
return 0;
}
size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
{
@@ -655,7 +700,6 @@ size_t ZSTD_decompressDCtx(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, const v
BYTE* op = ostart;
BYTE* const oend = ostart + maxDstSize;
size_t remainingSize = srcSize;
U32 magicNumber;
blockProperties_t blockProperties;
@@ -663,14 +707,23 @@ size_t ZSTD_decompressDCtx(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, const v
ctx->base = ctx->vBase = ctx->dictEnd = dst;
/* Frame Header */
if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
magicNumber = MEM_readLE32(src);
{
size_t frameHeaderSize;
if (srcSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1)
if (ZSTD_isLegacy(magicNumber))
return ZSTD_decompressLegacy(dst, maxDstSize, src, srcSize, magicNumber);
{
const U32 magicNumber = MEM_readLE32(src);
if (ZSTD_isLegacy(magicNumber))
return ZSTD_decompressLegacy(dst, maxDstSize, src, srcSize, magicNumber);
}
#endif
if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
frameHeaderSize = ZSTD_decodeFrameHeader_Part1(ctx, src, ZSTD_frameHeaderSize_min);
if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
if (srcSize < frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
ip += frameHeaderSize; remainingSize -= frameHeaderSize;
frameHeaderSize = ZSTD_decodeFrameHeader_Part2(ctx, src, frameHeaderSize);
if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
}
/* Loop on each block */
while (1)
@@ -722,7 +775,6 @@ size_t ZSTD_decompress(void* dst, size_t maxDstSize, const void* src, size_t src
/* ******************************
* Streaming Decompression API
********************************/
size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx)
{
return dctx->expected;
@@ -732,7 +784,7 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, con
{
/* Sanity check */
if (srcSize != ctx->expected) return ERROR(srcSize_wrong);
if (dst != ctx->previousDstEnd) /* not contiguous */
if (dst != ctx->previousDstEnd) /* not contiguous */
{
ctx->dictEnd = ctx->previousDstEnd;
if ((dst > ctx->base) && (dst < ctx->previousDstEnd)) /* rolling buffer : new segment right into tracked memory */
@@ -741,65 +793,85 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx* ctx, void* dst, size_t maxDstSize, con
ctx->base = dst;
}
/* Decompress : frame header */
if (ctx->phase == 0)
/* Decompress : frame header; part 1 */
switch (ctx->stage)
{
/* Check frame magic header */
U32 magicNumber = MEM_readLE32(src);
if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
ctx->phase = 1;
ctx->expected = ZSTD_blockHeaderSize;
return 0;
}
/* Decompress : block header */
if (ctx->phase == 1)
{
blockProperties_t bp;
size_t blockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
if (ZSTD_isError(blockSize)) return blockSize;
if (bp.blockType == bt_end)
case ZSTDds_getFrameHeaderSize :
{
ctx->expected = 0;
ctx->phase = 0;
/* get frame header size */
if (srcSize != ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong); /* impossible */
ctx->headerSize = ZSTD_decodeFrameHeader_Part1(ctx, src, ZSTD_frameHeaderSize_min);
if (ZSTD_isError(ctx->headerSize)) return ctx->headerSize;
memcpy(ctx->headerBuffer, src, ZSTD_frameHeaderSize_min);
if (ctx->headerSize > ZSTD_frameHeaderSize_min)
{
ctx->expected = ctx->headerSize - ZSTD_frameHeaderSize_min;
ctx->stage = ZSTDds_decodeFrameHeader;
return 0;
}
ctx->expected = 0; /* not necessary to copy more */
}
else
case ZSTDds_decodeFrameHeader:
{
ctx->expected = blockSize;
ctx->bType = bp.blockType;
ctx->phase = 2;
/* get frame header */
size_t result;
memcpy(ctx->headerBuffer + ZSTD_frameHeaderSize_min, src, ctx->expected);
result = ZSTD_decodeFrameHeader_Part2(ctx, ctx->headerBuffer, ctx->headerSize);
if (ZSTD_isError(result)) return result;
ctx->expected = ZSTD_blockHeaderSize;
ctx->stage = ZSTDds_decodeBlockHeader;
return 0;
}
ctx->previousDstEnd = dst;
return 0;
}
/* Decompress : block content */
{
size_t rSize;
switch(ctx->bType)
case ZSTDds_decodeBlockHeader:
{
case bt_compressed:
rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize);
break;
case bt_raw :
rSize = ZSTD_copyRawBlock(dst, maxDstSize, src, srcSize);
break;
case bt_rle :
return ERROR(GENERIC); /* not yet handled */
break;
case bt_end : /* should never happen (filtered at phase 1) */
rSize = 0;
break;
default:
return ERROR(GENERIC);
}
ctx->phase = 1;
ctx->expected = ZSTD_blockHeaderSize;
ctx->previousDstEnd = (char*)dst + rSize;
return rSize;
}
/* Decode block header */
blockProperties_t bp;
size_t blockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
if (ZSTD_isError(blockSize)) return blockSize;
if (bp.blockType == bt_end)
{
ctx->expected = 0;
ctx->stage = ZSTDds_getFrameHeaderSize;
}
else
{
ctx->expected = blockSize;
ctx->bType = bp.blockType;
ctx->stage = ZSTDds_decompressBlock;
}
ctx->previousDstEnd = dst;
return 0;
}
case 3:
{
/* Decompress : block content */
size_t rSize;
switch(ctx->bType)
{
case bt_compressed:
rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize);
break;
case bt_raw :
rSize = ZSTD_copyRawBlock(dst, maxDstSize, src, srcSize);
break;
case bt_rle :
return ERROR(GENERIC); /* not yet handled */
break;
case bt_end : /* should never happen (filtered at phase 1) */
rSize = 0;
break;
default:
return ERROR(GENERIC);
}
ctx->stage = ZSTDds_decodeBlockHeader;
ctx->expected = ZSTD_blockHeaderSize;
ctx->previousDstEnd = (char*)dst + rSize;
return rSize;
}
default:
return ERROR(GENERIC); /* impossible */
}
}