Fix ZSTD_estimateCStreamSize_usingCCtxParams()

It wasn't using the ZSTD_CCtx_params correctly. It must actualize
the compression parameters by calling ZSTD_getCParamsFromCCtxParams()
to get the real window log.

Tested by updating the streaming memory usage example in the next
commit. The CHECK() failed before this patch, and passes after.

I also added a unit test to zstreamtest.c that failed before this
patch, and passes after.
This commit is contained in:
Nick Terrell 2019-04-01 17:51:28 -07:00
parent 425ce5547c
commit 56682a7709
2 changed files with 19 additions and 3 deletions

View File

@ -1106,9 +1106,11 @@ size_t ZSTD_estimateCCtxSize(int compressionLevel)
size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params)
{
RETURN_ERROR_IF(params->nbWorkers > 0, GENERIC, "Estimate CCtx size is supported for single-threaded compression only.");
{ size_t const CCtxSize = ZSTD_estimateCCtxSize_usingCCtxParams(params);
size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << params->cParams.windowLog);
size_t const inBuffSize = ((size_t)1 << params->cParams.windowLog) + blockSize;
{ ZSTD_compressionParameters const cParams =
ZSTD_getCParamsFromCCtxParams(params, 0, 0);
size_t const CCtxSize = ZSTD_estimateCCtxSize_usingCCtxParams(params);
size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
size_t const inBuffSize = ((size_t)1 << cParams.windowLog) + blockSize;
size_t const outBuffSize = ZSTD_compressBound(blockSize) + 1;
size_t const streamingSize = inBuffSize + outBuffSize;

View File

@ -344,6 +344,20 @@ static int basicUnitTests(U32 seed, double compressibility)
DISPLAYLEVEL(3, "OK (%u bytes) \n", (unsigned)(cstreamSize + cdictSize));
}
/* context size functions */
DISPLAYLEVEL(3, "test%3i : estimate CStream size using CCtxParams : ", testNb++);
{ ZSTD_CCtx_params* const params = ZSTD_createCCtxParams();
size_t cstreamSize, cctxSize;
CHECK_Z( ZSTD_CCtxParams_setParameter(params, ZSTD_c_compressionLevel, 19) );
cstreamSize = ZSTD_estimateCStreamSize_usingCCtxParams(params);
CHECK_Z(cstreamSize);
cctxSize = ZSTD_estimateCCtxSize_usingCCtxParams(params);
CHECK_Z(cctxSize);
if (cstreamSize <= cctxSize + 2 * ZSTD_BLOCKSIZE_MAX) goto _output_error;
ZSTD_freeCCtxParams(params);
DISPLAYLEVEL(3, "OK \n");
}
DISPLAYLEVEL(3, "test%3i : check actual CStream size : ", testNb++);
{ size_t const s = ZSTD_sizeof_CStream(zc);
if (ZSTD_isError(s)) goto _output_error;