sharpetronics/zstd
1
0
Fork 0
mirror of https://github.com/facebook/zstd.git synced 2025-10-04 00:02:33 -04:00
Code Issues Projects Releases Wiki Activity

fix minor visual static analyzer warning

Browse Source 
it's a false positive,
but change the code nonetheless to make it more obvious to the static analyzer.
This commit is contained in:
Yann Collet 2024-02-25 19:45:32 -08:00
parent 038a8a906b
commit 1fafd0c4ae
1 changed files with 45 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

96
lib/compress/zstd_compress_superblock.c
View File

@ -500,16 +500,12 @@ static size_t ZSTD_compressSubBlock_multi(const seqStore_t* seqStorePtr,
size_t const targetCBlockSize = MAX(minTarget, cctxParams->targetCBlockSize);
int writeLitEntropy = (entropyMetadata->hufMetadata.hType == set_compressed);
int writeSeqEntropy = 1;
size_t nbSubBlocks = 1;
size_t avgLitCost, avgSeqCost, avgBlockBudget;
DEBUGLOG(5, "ZSTD_compressSubBlock_multi (srcSize=%u, litSize=%u, nbSeq=%u)",
(unsigned)srcSize, (unsigned)(lend-lstart), (unsigned)(send-sstart));
/* let's start by a general estimation for the full block */
if (nbSeqs == 0) {
nbSubBlocks = 1;
} else {
if (nbSeqs > 0) {
EstimatedBlockSize const ebs =
ZSTD_estimateSubBlockSize(lp, nbLiterals,
ofCodePtr, llCodePtr, mlCodePtr, nbSeqs,
@ -517,19 +513,17 @@ static size_t ZSTD_compressSubBlock_multi(const seqStore_t* seqStorePtr,
workspace, wkspSize,
writeLitEntropy, writeSeqEntropy);
/* quick estimation */
avgLitCost = nbLiterals ? (ebs.estLitSize * BYTESCALE) / nbLiterals : BYTESCALE;
avgSeqCost = ((ebs.estBlockSize - ebs.estLitSize) * BYTESCALE) / nbSeqs;
nbSubBlocks = (ebs.estBlockSize + (targetCBlockSize-1)) / targetCBlockSize;
size_t const avgLitCost = nbLiterals ? (ebs.estLitSize * BYTESCALE) / nbLiterals : BYTESCALE;
size_t const avgSeqCost = ((ebs.estBlockSize - ebs.estLitSize) * BYTESCALE) / nbSeqs;
size_t nbSubBlocks = (ebs.estBlockSize + (targetCBlockSize-1)) / targetCBlockSize;
size_t n, avgBlockBudget, blockBudgetSupp=0;
if (nbSubBlocks<1) nbSubBlocks=1;
avgBlockBudget = (ebs.estBlockSize * BYTESCALE) / nbSubBlocks;
DEBUGLOG(5, "estimated fullblock size=%u bytes ; avgLitCost=%.2f ; avgSeqCost=%.2f ; targetCBlockSize=%u, nbSubBlocks=%u ; avgBlockBudget=%.0f bytes",
(unsigned)ebs.estBlockSize, (double)avgLitCost/BYTESCALE, (double)avgSeqCost/BYTESCALE,
(unsigned)targetCBlockSize, (unsigned)nbSubBlocks, (double)avgBlockBudget/BYTESCALE);
}
/* compress and write sub-blocks */
{ size_t n;
size_t blockBudgetSupp = 0;
for (n=0; n+1 < nbSubBlocks; n++) {
/* determine nb of sequences for current sub-block + nbLiterals from next sequence */
size_t seqCount = sizeBlockSequences(sp, (size_t)(send-sp), avgBlockBudget + blockBudgetSupp, avgLitCost, avgSeqCost, n==0);
@ -577,50 +571,50 @@ static size_t ZSTD_compressSubBlock_multi(const seqStore_t* seqStorePtr,
} }
/* otherwise : do not compress yet, coalesce current block with next one */
}
} /* if (nbSeqs > 0) */
/* write last block */
DEBUGLOG(2, "Generate last sub-block: %u sequences remaining", (unsigned)(send - sp));
{ int litEntropyWritten = 0;
int seqEntropyWritten = 0;
size_t litSize = (size_t)(lend - lp);
size_t seqCount = (size_t)(send - sp);
const size_t decompressedSize =
ZSTD_seqDecompressedSize(seqStorePtr, sp, seqCount, litSize, 1);
size_t const cSize = ZSTD_compressSubBlock(&nextCBlock->entropy, entropyMetadata,
sp, seqCount,
lp, litSize,
llCodePtr, mlCodePtr, ofCodePtr,
cctxParams,
op, (size_t)(oend-op),
bmi2, writeLitEntropy, writeSeqEntropy,
&litEntropyWritten, &seqEntropyWritten,
lastBlock);
FORWARD_IF_ERROR(cSize, "ZSTD_compressSubBlock failed");
/* write last block */
DEBUGLOG(2, "Generate last sub-block: %u sequences remaining", (unsigned)(send - sp));
{ int litEntropyWritten = 0;
int seqEntropyWritten = 0;
size_t litSize = (size_t)(lend - lp);
size_t seqCount = (size_t)(send - sp);
const size_t decompressedSize =
ZSTD_seqDecompressedSize(seqStorePtr, sp, seqCount, litSize, 1);
size_t const cSize = ZSTD_compressSubBlock(&nextCBlock->entropy, entropyMetadata,
sp, seqCount,
lp, litSize,
llCodePtr, mlCodePtr, ofCodePtr,
cctxParams,
op, (size_t)(oend-op),
bmi2, writeLitEntropy, writeSeqEntropy,
&litEntropyWritten, &seqEntropyWritten,
lastBlock);
FORWARD_IF_ERROR(cSize, "ZSTD_compressSubBlock failed");
/* update pointers, the nb of literals borrowed from next sequence must be preserved */
if (cSize > 0 && cSize < decompressedSize) {
DEBUGLOG(2, "Last sub-block compressed %u bytes => %u bytes",
(unsigned)decompressedSize, (unsigned)cSize);
assert(ip + decompressedSize <= iend);
ip += decompressedSize;
lp += litSize;
op += cSize;
llCodePtr += seqCount;
mlCodePtr += seqCount;
ofCodePtr += seqCount;
/* Entropy only needs to be written once */
if (litEntropyWritten) {
writeLitEntropy = 0;
}
if (seqEntropyWritten) {
writeSeqEntropy = 0;
}
sp += seqCount;
blockBudgetSupp = 0;
/* update pointers, the nb of literals borrowed from next sequence must be preserved */
if (cSize > 0 && cSize < decompressedSize) {
DEBUGLOG(2, "Last sub-block compressed %u bytes => %u bytes",
(unsigned)decompressedSize, (unsigned)cSize);
assert(ip + decompressedSize <= iend);
ip += decompressedSize;
lp += litSize;
op += cSize;
llCodePtr += seqCount;
mlCodePtr += seqCount;
ofCodePtr += seqCount;
/* Entropy only needs to be written once */
if (litEntropyWritten) {
writeLitEntropy = 0;
}
if (seqEntropyWritten) {
writeSeqEntropy = 0;
}
sp += seqCount;
}
}
if (writeLitEntropy) {
DEBUGLOG(5, "Literal entropy tables were never written");
ZSTD_memcpy(&nextCBlock->entropy.huf, &prevCBlock->entropy.huf, sizeof(prevCBlock->entropy.huf));
@ -653,8 +647,8 @@ static size_t ZSTD_compressSubBlock_multi(const seqStore_t* seqStorePtr,
}
}
DEBUGLOG(5, "ZSTD_compressSubBlock_multi compressed %u subBlocks: total compressed size = %u",
(unsigned)nbSubBlocks, (unsigned)(op-ostart));
DEBUGLOG(5, "ZSTD_compressSubBlock_multi compressed all subBlocks: total compressed size = %u",
(unsigned)(op-ostart));
return (size_t)(op-ostart);
}