slightly adjusted default-distribution threshold

depending on strategy. fast favors faster compression and decompression speeds.
2018-06-26 20:10:45 -07:00
parent ff773bfcde
commit 4489daec09
2 changed files with 26 additions and 1 deletions
@@ -1819,8 +1819,11 @@ ZSTD_selectEncodingType(
    if (strategy < ZSTD_lazy) {
        if (isDefaultAllowed) {
            size_t const staticFse_nbSeq_max = 1000;
-            size_t const dynamicFse_nbSeq_min = (size_t)1 << defaultNormLog;  /* 32 for offset, 64 for lengths */
+            size_t const mult = 10 - strategy;
+            size_t const baseLog = 3;
+            size_t const dynamicFse_nbSeq_min = (((size_t)1 << defaultNormLog) * mult) >> baseLog;  /* 28-36 for offset, 56-72 for lengths */
            assert(defaultNormLog >= 5 && defaultNormLog <= 6);  /* xx_DEFAULTNORMLOG */
+            assert(mult <= 9 && mult >= 7);
            if ( (*repeatMode == FSE_repeat_valid)
              && (nbSeq < staticFse_nbSeq_max) ) {
                DEBUGLOG(5, "Selected set_repeat");