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[lib] Fix single-pass mode for empty frames

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This commit is contained in:
Nick Terrell 2020-04-27 18:10:45 -07:00
parent a4ff217baf
commit f33de06c3e
2 changed files with 28 additions and 1 deletions
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3
lib/decompress/zstd_decompress.c
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@ -1660,7 +1660,8 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
} }
/* check for single-pass mode opportunity */
if (zds->fParams.frameContentSize && zds->fParams.windowSize /* skippable frame if == 0 */
if (zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
&& zds->fParams.frameType != ZSTD_skippableFrame
&& (U64)(size_t)(oend-op) >= zds->fParams.frameContentSize) {
size_t const cSize = ZSTD_findFrameCompressedSize(istart, iend-istart);
if (cSize <= (size_t)(iend-istart)) {

26
tests/zstreamtest.c
View File

@ -641,6 +641,32 @@ static int basicUnitTests(U32 seed, double compressibility)
}
DISPLAYLEVEL(3, "OK \n");
/* Decompression single pass with empty frame */
cSize = ZSTD_compress(compressedBuffer, compressedBufferSize, NULL, 0, 1);
CHECK_Z(cSize);
DISPLAYLEVEL(3, "test%3i : ZSTD_decompressStream() single pass on empty frame : ", testNb++);
{ ZSTD_DCtx* dctx = ZSTD_createDCtx();
size_t const dctxSize = ZSTD_sizeof_DCtx(dctx);
CHECK_Z(ZSTD_DCtx_setParameter(dctx, ZSTD_d_stableOutBuffer, 1));
outBuff.dst = decodedBuffer;
outBuff.pos = 0;
outBuff.size = CNBufferSize;
inBuff.src = compressedBuffer;
inBuff.size = cSize;
inBuff.pos = 0;
{ size_t const r = ZSTD_decompressStream(dctx, &outBuff, &inBuff);
CHECK_Z(r);
CHECK(r != 0, "Entire frame must be decompressed");
CHECK(outBuff.pos != 0, "Wrong size!");
CHECK(memcmp(CNBuffer, outBuff.dst, CNBufferSize) != 0, "Corruption!");
}
CHECK(dctxSize != ZSTD_sizeof_DCtx(dctx), "No buffers allocated");
ZSTD_freeDCtx(dctx);
}
DISPLAYLEVEL(3, "OK \n");
/* Decompression with ZSTD_d_stableOutBuffer */
cSize = ZSTD_compress(compressedBuffer, compressedBufferSize, CNBuffer, CNBufferSize, 1);
CHECK_Z(cSize);