facebook/zstd
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add a fallback in case the total blocksize of split blocks exceeds raw block size

Browse Source
This commit is contained in:
Sen Huang 2021-03-22 14:38:21 -07:00
parent c90e81a692
commit 0ef1f935b7
1 changed files with 9 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
lib/compress/zstd_compress.c
View File

@ -3327,6 +3327,7 @@ static size_t ZSTD_compressBlock_splitBlock_internal(ZSTD_CCtx* zc, void* dst, s
seqStore_t nextSeqStore; seqStore_t nextSeqStore;
seqStore_t currSeqStore; seqStore_t currSeqStore;
U32 canEmitRLEorNoCompress = 1; U32 canEmitRLEorNoCompress = 1;
const size_t dstCapacityInitial = dstCapacity;
DEBUGLOG(5, "ZSTD_compressBlock_splitBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)", DEBUGLOG(5, "ZSTD_compressBlock_splitBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
(unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit, (unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit,
@ -3370,6 +3371,14 @@ static size_t ZSTD_compressBlock_splitBlock_internal(ZSTD_CCtx* zc, void* dst, s
cSize += cSizeChunk; cSize += cSizeChunk;
currSeqStore = nextSeqStore; currSeqStore = nextSeqStore;
} }
if (cSize > ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize) {
/* If too large, recompress the original block to avoid any chance of a single block exceeding ZSTD_BLOCKSIZE_MAX */
cSize = ZSTD_compressSequences_singleBlock(zc, &zc->seqStore, (BYTE*)dst, dstCapacityInitial, (const BYTE*)src, blockSize, lastBlock, 1);
FORWARD_IF_ERROR(cSize, "Compressing single block from splitBlock_internal() fallback failed!");
DEBUGLOG(5, "ZSTD_compressBlock_splitBlock_internal: Compressed split block too large, recompressed");
}
assert(cSize <= ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize);
return cSize; return cSize;
} }