Feature Request: setMaxCompression from zstd-1.5.7

[dajhorn]

Commit d3ebf11 imports zstd-1.5.7, which has a new exhaustive setMaxCompression feature.

It would be nice for smv.exe to expose this new compression level on the command line and for smartvs.exe to expose it in the GUI.

[gvollant]

setMaxCompression function is not on the zstd library, only on CLI

[dajhorn]

Right; this feature request is for a smv -compress level that uses the same library argument as the zstd cli:

static void setMaxCompression(ZSTD_compressionParameters* params)
{
    params->windowLog = ZSTD_WINDOWLOG_MAX;
    params->chainLog = ZSTD_CHAINLOG_MAX;
    params->hashLog = ZSTD_HASHLOG_MAX;
    params->searchLog = ZSTD_SEARCHLOG_MAX;
    params->minMatch = ZSTD_MINMATCH_MIN;
    params->targetLength = ZSTD_TARGETLENGTH_MAX;
    params->strategy = ZSTD_STRATEGY_MAX;
    g_overlapLog = ZSTD_OVERLAPLOG_MAX;
    g_ldmHashLog = ZSTD_LDM_HASHLOG_MAX;
    g_ldmHashRateLog = 0; /* automatically derived */
    g_ldmMinMatch = 16; /* heuristic */
    g_ldmBucketSizeLog = ZSTD_LDM_BUCKETSIZELOG_MAX;
}

Doing this sometimes reduces the size of 64-bit sized SVF files by a few percent. I use SmartVersion instead of xdelta3 for archiving large datasets in a place where saving a gigabyte of data is worth any amount of CPU time.