more complete support for literals repeat mode
This commit is contained in:
Yann Collet
parent
9f2d82d4a4
commit
772d912c2f
@ -460,140 +460,130 @@ static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity, const void* src,
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size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
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const void* src, size_t srcSize) /* note : srcSize < BLOCKSIZE */
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{
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const BYTE* const istart = (const BYTE*) src;
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if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
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switch((litBlockType_t)(istart[0] & 3))
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{
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case lbt_huffman:
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if (srcSize < 5) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for lhSize, + cSize (+nbSeq) */
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{ size_t lhSize, litSize, litCSize;
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U32 singleStream=0;
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U32 const lhlCode = (istart[0] >> 2) & 3;
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U32 const lhc = MEM_readLE32(istart);
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switch(lhlCode)
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{
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case 0: case 1: default: /* note : default is impossible, since lhlCode into [0..3] */
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/* 2 - 2 - 10 - 10 */
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{ singleStream = lhlCode;
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lhSize = 3;
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litSize = (lhc >> 4) & 0x3FF;
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litCSize = (lhc >> 14) & 0x3FF;
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break;
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{ const BYTE* const istart = (const BYTE*) src;
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litBlockType_t const litBlockType = (litBlockType_t)(istart[0] & 3);
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switch(litBlockType)
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{
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case lbt_repeat:
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if (dctx->litEntropy==0) return ERROR(dictionary_corrupted);
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/* fall-through */
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case lbt_huffman:
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if (srcSize < 5) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for case 3 */
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{ size_t lhSize, litSize, litCSize;
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U32 singleStream=0;
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U32 const lhlCode = (istart[0] >> 2) & 3;
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U32 const lhc = MEM_readLE32(istart);
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switch(lhlCode)
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{
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case 0: case 1: default: /* note : default is impossible, since lhlCode into [0..3] */
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/* 2 - 2 - 10 - 10 */
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{ singleStream = lhlCode;
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lhSize = 3;
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litSize = (lhc >> 4) & 0x3FF;
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litCSize = (lhc >> 14) & 0x3FF;
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break;
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}
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case 2:
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/* 2 - 2 - 14 - 14 */
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{ lhSize = 4;
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litSize = (lhc >> 4) & 0x3FFF;
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litCSize = lhc >> 18;
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break;
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}
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case 3:
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/* 2 - 2 - 18 - 18 */
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{ lhSize = 5;
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litSize = (lhc >> 4) & 0x3FFFF;
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litCSize = (lhc >> 22) + (istart[4] << 10);
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break;
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}
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}
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case 2:
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/* 2 - 2 - 14 - 14 */
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{ lhSize = 4;
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litSize = (lhc >> 4) & 0x3FFF;
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litCSize = lhc >> 18;
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break;
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}
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case 3:
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/* 2 - 2 - 18 - 18 */
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{ lhSize = 5;
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litSize = (lhc >> 4) & 0x3FFFF;
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litCSize = (lhc >> 22) + (istart[4] << 10);
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break;
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}
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}
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if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
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if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
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if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
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if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
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if (HUF_isError(singleStream ?
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HUF_decompress1X2_DCtx(dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize) :
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HUF_decompress4X_hufOnly (dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize) ))
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return ERROR(corruption_detected);
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if (HUF_isError((litBlockType==lbt_repeat) ?
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( singleStream ?
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HUF_decompress1X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->hufTable) :
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HUF_decompress4X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->hufTable) ) :
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( singleStream ?
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HUF_decompress1X2_DCtx(dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize) :
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HUF_decompress4X_hufOnly (dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize)) ))
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return ERROR(corruption_detected);
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dctx->litPtr = dctx->litBuffer;
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dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
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dctx->litSize = litSize;
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dctx->litEntropy = 1;
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return litCSize + lhSize;
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}
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case lbt_repeat:
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{ size_t litSize, litCSize, lhSize;
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U32 const lhc = MEM_readLE24(istart) >> 4;
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if ((((istart[0]) >> 2) & 3) != 1) /* only case supported for now : small litSize, single stream */
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return ERROR(corruption_detected);
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if (dctx->litEntropy==0)
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return ERROR(dictionary_corrupted);
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/* 2 - 2 - 10 - 10 */
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lhSize = 3;
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litSize = lhc & 0x3FF;
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litCSize = lhc >> 10;
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if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
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{ size_t const errorCode = HUF_decompress1X4_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->hufTable);
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if (HUF_isError(errorCode)) return ERROR(corruption_detected);
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}
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dctx->litPtr = dctx->litBuffer;
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dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
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dctx->litSize = litSize;
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return litCSize + lhSize;
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}
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case lbt_raw:
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{ size_t litSize, lhSize;
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U32 const lhlCode = ((istart[0]) >> 2) & 3;
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switch(lhlCode)
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{
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case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
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lhSize = 1;
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litSize = istart[0] >> 3;
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break;
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case 1:
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lhSize = 2;
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litSize = MEM_readLE16(istart) >> 4;
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break;
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case 3:
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lhSize = 3;
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litSize = MEM_readLE24(istart) >> 4;
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break;
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}
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if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */
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if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
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memcpy(dctx->litBuffer, istart+lhSize, litSize);
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dctx->litPtr = dctx->litBuffer;
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dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+8;
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dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
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dctx->litSize = litSize;
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dctx->litEntropy = 1;
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return litCSize + lhSize;
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}
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case lbt_raw:
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{ size_t litSize, lhSize;
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U32 const lhlCode = ((istart[0]) >> 2) & 3;
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switch(lhlCode)
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{
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case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
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lhSize = 1;
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litSize = istart[0] >> 3;
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break;
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case 1:
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lhSize = 2;
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litSize = MEM_readLE16(istart) >> 4;
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break;
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case 3:
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lhSize = 3;
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litSize = MEM_readLE24(istart) >> 4;
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break;
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}
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if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */
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if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
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memcpy(dctx->litBuffer, istart+lhSize, litSize);
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dctx->litPtr = dctx->litBuffer;
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dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+8;
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dctx->litSize = litSize;
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return lhSize+litSize;
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}
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/* direct reference into compressed stream */
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dctx->litPtr = istart+lhSize;
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dctx->litBufSize = srcSize-lhSize;
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dctx->litSize = litSize;
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return lhSize+litSize;
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}
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/* direct reference into compressed stream */
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dctx->litPtr = istart+lhSize;
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dctx->litBufSize = srcSize-lhSize;
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dctx->litSize = litSize;
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return lhSize+litSize;
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}
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case lbt_rle:
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{ U32 const lhlCode = ((istart[0]) >> 2) & 3;
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size_t litSize, lhSize;
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switch(lhlCode)
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{
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case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
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lhSize = 1;
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litSize = istart[0] >> 3;
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break;
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case 1:
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lhSize = 2;
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litSize = MEM_readLE16(istart) >> 4;
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break;
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case 3:
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lhSize = 3;
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litSize = MEM_readLE24(istart) >> 4;
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if (srcSize<4) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */
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break;
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case lbt_rle:
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{ U32 const lhlCode = ((istart[0]) >> 2) & 3;
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size_t litSize, lhSize;
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switch(lhlCode)
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{
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case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
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lhSize = 1;
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litSize = istart[0] >> 3;
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break;
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case 1:
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lhSize = 2;
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litSize = MEM_readLE16(istart) >> 4;
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break;
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case 3:
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lhSize = 3;
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litSize = MEM_readLE24(istart) >> 4;
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if (srcSize<4) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */
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break;
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}
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if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
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memset(dctx->litBuffer, istart[lhSize], litSize);
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dctx->litPtr = dctx->litBuffer;
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dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
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dctx->litSize = litSize;
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return lhSize+1;
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}
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if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
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memset(dctx->litBuffer, istart[lhSize], litSize);
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dctx->litPtr = dctx->litBuffer;
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dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
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dctx->litSize = litSize;
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return lhSize+1;
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default:
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return ERROR(corruption_detected); /* impossible */
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}
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default:
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return ERROR(corruption_detected); /* impossible */
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}
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}
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