Function ZSTD_resetCCtx_internal

freebsd/contrib/openzfs/module/zstd/lib/zstd.c:14503–14671

! ZSTD_resetCCtx_internal() : note : `params` are assumed fully validated at this stage */

/*! ZSTD_resetCCtx_internal() :
    note : `params` are assumed fully validated at this stage */
static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
                                      ZSTD_CCtx_params params,
                                      U64 const pledgedSrcSize,
                                      ZSTD_compResetPolicy_e const crp,
                                      ZSTD_buffered_policy_e const zbuff)
{
    ZSTD_cwksp* const ws = &zc->workspace;
    DEBUGLOG(4, "ZSTD_resetCCtx_internal: pledgedSrcSize=%u, wlog=%u",
                (U32)pledgedSrcSize, params.cParams.windowLog);
    assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));

    zc->isFirstBlock = 1;

    if (params.ldmParams.enableLdm) {
        /* Adjust long distance matching parameters */
        ZSTD_ldm_adjustParameters(&params.ldmParams, &params.cParams);
        assert(params.ldmParams.hashLog >= params.ldmParams.bucketSizeLog);
        assert(params.ldmParams.hashRateLog < 32);
        zc->ldmState.hashPower = ZSTD_rollingHash_primePower(params.ldmParams.minMatchLength);
    }

    {   size_t const windowSize = MAX(1, (size_t)MIN(((U64)1 << params.cParams.windowLog), pledgedSrcSize));
        size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
        U32    const divider = (params.cParams.minMatch==3) ? 3 : 4;
        size_t const maxNbSeq = blockSize / divider;
        size_t const tokenSpace = ZSTD_cwksp_alloc_size(WILDCOPY_OVERLENGTH + blockSize)
                                + ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(seqDef))
                                + 3 * ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(BYTE));
        size_t const buffOutSize = (zbuff==ZSTDb_buffered) ? ZSTD_compressBound(blockSize)+1 : 0;
        size_t const buffInSize = (zbuff==ZSTDb_buffered) ? windowSize + blockSize : 0;
        size_t const matchStateSize = ZSTD_sizeof_matchState(&params.cParams, /* forCCtx */ 1);
        size_t const maxNbLdmSeq = ZSTD_ldm_getMaxNbSeq(params.ldmParams, blockSize);

        ZSTD_indexResetPolicy_e needsIndexReset = zc->initialized ? ZSTDirp_continue : ZSTDirp_reset;

        if (ZSTD_indexTooCloseToMax(zc->blockState.matchState.window)) {
            needsIndexReset = ZSTDirp_reset;
        }

        if (!zc->staticSize) ZSTD_cwksp_bump_oversized_duration(ws, 0);

        /* Check if workspace is large enough, alloc a new one if needed */
        {   size_t const cctxSpace = zc->staticSize ? ZSTD_cwksp_alloc_size(sizeof(ZSTD_CCtx)) : 0;
            size_t const entropySpace = ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE);
            size_t const blockStateSpace = 2 * ZSTD_cwksp_alloc_size(sizeof(ZSTD_compressedBlockState_t));
            size_t const bufferSpace = ZSTD_cwksp_alloc_size(buffInSize) + ZSTD_cwksp_alloc_size(buffOutSize);
            size_t const ldmSpace = ZSTD_ldm_getTableSize(params.ldmParams);
            size_t const ldmSeqSpace = ZSTD_cwksp_alloc_size(maxNbLdmSeq * sizeof(rawSeq));

            size_t const neededSpace =
                cctxSpace +
                entropySpace +
                blockStateSpace +
                ldmSpace +
                ldmSeqSpace +
                matchStateSize +
                tokenSpace +
                bufferSpace;