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Merge pull request #2390 from animalize/clamp_level

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Clamp compression level
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Nick Terrell 2020-12-02 14:35:58 -08:00 committed by GitHub
commit 894ae36675
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1 changed files with 12 additions and 4 deletions
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16
lib/compress/zstd_compress.c
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@ -5139,13 +5139,21 @@ static ZSTD_compressionParameters ZSTD_getCParams_internal(int compressionLevel,
{
U64 const rSize = ZSTD_getCParamRowSize(srcSizeHint, dictSize, mode);
U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB);
int row = compressionLevel;
int row;
DEBUGLOG(5, "ZSTD_getCParams_internal (cLevel=%i)", compressionLevel);
/* row */
if (compressionLevel == 0) row = ZSTD_CLEVEL_DEFAULT; /* 0 == default */
if (compressionLevel < 0) row = 0; /* entry 0 is baseline for fast mode */
if (compressionLevel > ZSTD_MAX_CLEVEL) row = ZSTD_MAX_CLEVEL;
else if (compressionLevel < 0) row = 0; /* entry 0 is baseline for fast mode */
else if (compressionLevel > ZSTD_MAX_CLEVEL) row = ZSTD_MAX_CLEVEL;
else row = compressionLevel;
{ ZSTD_compressionParameters cp = ZSTD_defaultCParameters[tableID][row];
if (compressionLevel < 0) cp.targetLength = (unsigned)(-compressionLevel); /* acceleration factor */
/* acceleration factor */
if (compressionLevel < 0) {
int const clampedCompressionLevel = MAX(ZSTD_minCLevel(), compressionLevel);
cp.targetLength = (unsigned)(-clampedCompressionLevel);
}
/* refine parameters based on srcSize & dictSize */
return ZSTD_adjustCParams_internal(cp, srcSizeHint, dictSize, mode);
}