diff options
Diffstat (limited to 'lib/lz4opt.h')
| -rw-r--r-- | lib/lz4opt.h | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/lib/lz4opt.h b/lib/lz4opt.h index 69c48dc..f8eb50e 100644 --- a/lib/lz4opt.h +++ b/lib/lz4opt.h @@ -252,20 +252,29 @@ static int LZ4HC_compress_optimal ( continue; } - /* set prices using matches at position = 0 */ + /* set prices for first positions (literals) */ + { size_t rPos; + for (rPos = 0 ; rPos < MINMATCH ; rPos++) { + int const cost = (int)LZ4HC_literalsPrice(llen + rPos); + opt[rPos].mlen = 1; + opt[rPos].off = 0; + opt[rPos].litlen = (int)(llen + rPos); + opt[rPos].price = cost; + DEBUGLOG(7, "rPos:%3u => cost:%3i (litlen=%i)", + (U32)rPos, cost, opt[rPos].litlen); + } } + /* set prices using matches found for rPos = 0 */ { size_t matchNb; for (matchNb = 0; matchNb < match_num; matchNb++) { size_t mlen = (matchNb>0) ? (size_t)matches[matchNb-1].len+1 : MINMATCH; best_mlen = matches[matchNb].len; /* necessarily < sufficient_len < LZ4_OPT_NUM */ for ( ; mlen <= best_mlen ; mlen++) { - size_t const cost = LZ4HC_sequencePrice(llen, mlen) - LZ4HC_literalsPrice(llen); + size_t const cost = LZ4HC_sequencePrice(llen, mlen); SET_PRICE(mlen, mlen, matches[matchNb].off, 0, cost); /* updates last_match_pos and opt[pos] */ } } } - assert(last_match_pos >= MINMATCH); /* check further positions */ - opt[0].mlen = opt[1].mlen = 1; for (cur = 1; cur <= last_match_pos; cur++) { const BYTE* const curPtr = ip + cur; @@ -274,11 +283,7 @@ static int LZ4HC_compress_optimal ( if (opt[cur-1].mlen == 1) { /* no match at previous position */ litlen = opt[cur-1].litlen + 1; - if (cur > litlen) { - price = opt[cur - litlen].price + LZ4HC_literalsPrice(litlen); - } else { - price = LZ4HC_literalsPrice(llen + litlen) - LZ4HC_literalsPrice(llen); - } + price = opt[cur-1].price - LZ4HC_literalsPrice(litlen-1) + LZ4HC_literalsPrice(litlen); } else { litlen = 1; price = opt[cur - 1].price + LZ4HC_literalsPrice(1); @@ -313,7 +318,7 @@ static int LZ4HC_compress_optimal ( if (cur > ll) price = opt[cur - ll].price + LZ4HC_sequencePrice(ll, ml); else - price = LZ4HC_sequencePrice(llen + ll, ml) - LZ4HC_literalsPrice(llen); + price = LZ4HC_sequencePrice(ll, ml); } else { ll = 0; price = opt[cur].price + LZ4HC_sequencePrice(0, ml); |