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fixed RLE detection test

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This commit is contained in:
Yann Collet 2024-10-17 13:21:55 -07:00
parent 83a3402a92
commit f83ed087f6
2 changed files with 16 additions and 13 deletions
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10
lib/compress/zstd_compress.c
View File

@ -4491,14 +4491,14 @@ static void ZSTD_overflowCorrectIfNeeded(ZSTD_matchState_t* ms,
static size_t ZSTD_optimalBlockSize(const void* src, size_t srcSize, size_t blockSizeMax, ZSTD_strategy strat, S64 savings) static size_t ZSTD_optimalBlockSize(const void* src, size_t srcSize, size_t blockSizeMax, ZSTD_strategy strat, S64 savings)
{ {
if (srcSize <= 128 KB || blockSizeMax < 128 KB)
return MIN(srcSize, blockSizeMax);
(void)strat;
if (strat >= ZSTD_btlazy2) if (strat >= ZSTD_btlazy2)
return ZSTD_splitBlock_4k(src, srcSize, blockSizeMax); return ZSTD_splitBlock_4k(src, srcSize, blockSizeMax);
if (srcSize <= 128 KB || blockSizeMax < 128 KB)
return MIN(srcSize, blockSizeMax);
/* blind split strategy /* blind split strategy
* heuristic, just tested as being "generally better" * no cpu cost, but can over-split homegeneous data.
* do not split incompressible data though: just respect the 3 bytes per block overhead limit. * heuristic, tested as being "generally better".
* do not split incompressible data though: respect the 3 bytes per block overhead limit.
*/ */
return savings ? 92 KB : 128 KB; return savings ? 92 KB : 128 KB;
} }

19
tests/fuzzer.c
View File

@ -3653,16 +3653,19 @@ static int basicUnitTests(U32 const seed, double compressibility)
ZSTD_freeDCtx(dctx); ZSTD_freeDCtx(dctx);
} }
/* long rle test */ /* rle detection test: must compress better blocks with a single identical byte repeated */
{ size_t sampleSize = 0; { size_t sampleSize = 0;
size_t expectedCompressedSize = 39; /* block 1, 2: compressed, block 3: RLE, zstd 1.4.4 */ size_t maxCompressedSize = 46; /* block 1, 2: compressed, block 3: RLE, zstd 1.4.4 */
DISPLAYLEVEL(3, "test%3i : Long RLE test : ", testNb++); DISPLAYLEVEL(3, "test%3i : RLE detection test : ", testNb++);
memset((char*)CNBuffer+sampleSize, 'B', 256 KB - 1); memset((char*)CNBuffer+sampleSize, 'B', 256 KB - 2);
sampleSize += 256 KB - 1; sampleSize += 256 KB - 2;
memset((char*)CNBuffer+sampleSize, 'A', 96 KB); memset((char*)CNBuffer+sampleSize, 'A', 100 KB);
sampleSize += 96 KB; sampleSize += 100 KB;
cSize = ZSTD_compress(compressedBuffer, ZSTD_compressBound(sampleSize), CNBuffer, sampleSize, 1); cSize = ZSTD_compress(compressedBuffer, ZSTD_compressBound(sampleSize), CNBuffer, sampleSize, 1);
if (ZSTD_isError(cSize) || cSize > expectedCompressedSize) goto _output_error; if (ZSTD_isError(cSize) || cSize > maxCompressedSize) {
DISPLAYLEVEL(4, "error: cSize %u > %u expected ! \n", (unsigned)cSize, (unsigned)maxCompressedSize);
goto _output_error;
}
{ CHECK_NEWV(regenSize, ZSTD_decompress(decodedBuffer, sampleSize, compressedBuffer, cSize)); { CHECK_NEWV(regenSize, ZSTD_decompress(decodedBuffer, sampleSize, compressedBuffer, cSize));
if (regenSize!=sampleSize) goto _output_error; } if (regenSize!=sampleSize) goto _output_error; }
DISPLAYLEVEL(3, "OK \n"); DISPLAYLEVEL(3, "OK \n");