lib/zlib_deflate/deflate.c

99 /* Minimum amount of lookahead, except at the end of the input file.
405     if (strm->avail_in != 0 || s->lookahead != 0 ||
547     s->lookahead = 0;
560  * OUT assertion: the match length is not greater than s->lookahead.
609     if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
611     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
631          * lookahead only every 4th comparison; the 128th check will be made
634          * to check more often for insufficient lookahead.
669         /* We check for insufficient lookahead only every 8th comparison;
700     if ((uInt)best_len <= s->lookahead) return best_len;
701     return s->lookahead;
735  * Fill the window when the lookahead becomes insufficient.
736  * Updates strstart and lookahead.
738  * IN assertion: lookahead < MIN_LOOKAHEAD
754         more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
757         if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
762              * and lookahead == 1 (input done one byte at time)
766         /* If the window is almost full and there is insufficient lookahead,
804          *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
805          *    more == window_size - lookahead - strstart
810          *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
816         n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
817         s->lookahead += n;
820         if (s->lookahead >= MIN_MATCH) {
831     } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
882         if (s->lookahead <= 1) {
888             if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
890             if (s->lookahead == 0) break; /* flush the current block */
894 	s->strstart += s->lookahead;
895 	s->lookahead = 0;
901 	    s->lookahead = (uInt)(s->strstart - max_start);
932         /* Make sure that we always have enough lookahead, except
937         if (s->lookahead < MIN_LOOKAHEAD) {
939             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
942             if (s->lookahead == 0) break; /* flush the current block */
948         if (s->lookahead >= MIN_MATCH) {
971             s->lookahead -= s->match_length;
977                 s->lookahead >= MIN_MATCH) {
995                 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1003             s->lookahead--;
1027         /* Make sure that we always have enough lookahead, except
1032         if (s->lookahead < MIN_LOOKAHEAD) {
1034             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1037             if (s->lookahead == 0) break; /* flush the current block */
1043         if (s->lookahead >= MIN_MATCH) {
1077             uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1087              * enough lookahead, the last two strings are not inserted in
1090             s->lookahead -= s->prev_length-1;
1113             s->lookahead--;
1121             s->lookahead--;