libkern/zlib/deflate.c

141 /* Minimum amount of lookahead, except at the end of the input file.
373      * s->lookahead stays null, so s->ins_h will be recomputed at the next
815     if (strm->avail_in != 0 || s->lookahead != 0 ||
1031     s->lookahead = 0;
1050  * OUT assertion: the match length is not greater than s->lookahead.
1099     if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1101     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1109          * for insufficient lookahead only occur occasionally for performance
1112          * However the length of the match is limited to the lookahead, so
1126          * lookahead only every 4th comparison; the 128th check will be made
1129          * to check more often for insufficient lookahead.
1164         /* We check for insufficient lookahead only every 8th comparison;
1195     if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1196     return s->lookahead;
1218     Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1237     /* We check for insufficient lookahead only every 8th comparison;
1254     return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
1286  * Fill the window when the lookahead becomes insufficient.
1287  * Updates strstart and lookahead.
1289  * IN assertion: lookahead < MIN_LOOKAHEAD
1304         more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1308             if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1313                  * strstart == 0 && lookahead == 1 (input done a byte at time)
1319         /* If the window is almost full and there is insufficient lookahead,
1359          *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1360          *    more == window_size - lookahead - strstart
1365          *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1371         n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1372         s->lookahead += n;
1375         if (s->lookahead >= MIN_MATCH) {
1386     } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1436         if (s->lookahead <= 1) {
1442             if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1444             if (s->lookahead == 0) break; /* flush the current block */
1448         s->strstart += s->lookahead;
1449         s->lookahead = 0;
1455             s->lookahead = (uInt)(s->strstart - max_start);
1485         /* Make sure that we always have enough lookahead, except
1490         if (s->lookahead < MIN_LOOKAHEAD) {
1492             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1495             if (s->lookahead == 0) break; /* flush the current block */
1501         if (s->lookahead >= MIN_MATCH) {
1533             s->lookahead -= s->match_length;
1540                 s->lookahead >= MIN_MATCH) {
1560                 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1568             s->lookahead--;
1592         /* Make sure that we always have enough lookahead, except
1597         if (s->lookahead < MIN_LOOKAHEAD) {
1599             if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1602             if (s->lookahead == 0) break; /* flush the current block */
1608         if (s->lookahead >= MIN_MATCH) {
1647             uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1657              * enough lookahead, the last two strings are not inserted in
1660             s->lookahead -= s->prev_length-1;
1684             s->lookahead--;
1692             s->lookahead--;
1723         /* Make sure that we always have enough lookahead, except
1727         if (s->lookahead < MAX_MATCH) {
1729             if (s->lookahead < MAX_MATCH && flush == Z_NO_FLUSH) {
1732             if (s->lookahead == 0) break; /* flush the current block */
1738             max = s->lookahead < MAX_MATCH ? s->lookahead : MAX_MATCH;
1751             s->lookahead -= run;
1757             s->lookahead--;