2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Edward Wang at The University of California, Berkeley.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 static char sccsid[] = "@(#)compress.c 8.1 (Berkeley) 6/6/93";
51 /* tunable parameters */
57 int cc_token_max = 8; /* <= TOKEN_MAX */
58 int cc_token_min = 2; /* > tt.tt_put_token_cost */
62 int cc_bufsize = 1024 * 3; /* XXX, or 80 * 24 * 2 */
74 char string[TOKEN_MAX];
80 long time; /* time last seen */
81 short bcount; /* count in this buffer */
82 short ccount; /* count in compression */
83 short places; /* places in the buffer */
84 short code; /* token code */
85 struct cc *qforw, *qback;
86 struct cc *hforw, **hback;
89 short cc_thresholds[TOKEN_MAX + 1];
90 #define thresh(length) (cc_thresholds[length])
91 #define threshp(code, count, length) \
92 ((code) >= 0 || (short) (count) >= cc_thresholds[length])
95 short cc_wthresholds[TOKEN_MAX + 1];
96 #define wthresh(length) (cc_wthresholds[length])
97 #define wthreshp(weight, length) ((short) (weight) >= cc_wthresholds[length])
99 #define wthreshp(weight, length) (0)
103 short cc_wlimits[TOKEN_MAX + 1];
104 #define wlimit(length) (cc_wlimits[length])
107 #define put_token_score(length) ((length) - tt.tt_put_token_cost)
109 int cc_score_adjustments[TOKEN_MAX + 1][8]; /* XXX, 8 > max of cc_thresholds */
110 #define score_adjust(score, p) \
112 int length = (p)->length; \
113 int ccount = (p)->ccount; \
114 if (threshp((p)->code, ccount, length) || \
115 wthreshp((p)->weight, length)) /* XXX */ \
116 (score) -= length - tt.tt_put_token_cost; \
118 (score) += cc_score_adjustments[length][ccount]; \
121 int cc_initial_scores[TOKEN_MAX + 1][8]; /* XXX, 8 > max of cc_thresholds */
123 struct cc cc_q0a, cc_q0b, cc_q1a, cc_q1b;
125 #define qinsert(p1, p2) \
127 register struct cc *forw = (p1)->qforw; \
128 register struct cc *back = (p1)->qback; \
129 back->qforw = forw; \
130 forw->qback = back; \
131 forw = (p2)->qforw; \
132 (p1)->qforw = forw; \
133 forw->qback = (p1); \
134 (p2)->qforw = (p1); \
135 (p1)->qback = (p2); \
138 #define qinsertq(q, p) \
139 ((q)->qforw == (q) ? 0 : \
140 ((q)->qback->qforw = (p)->qforw, \
141 (p)->qforw->qback = (q)->qback, \
142 (q)->qforw->qback = (p), \
143 (p)->qforw = (q)->qforw, \
148 #define HSIZE (1 << H)
149 #define hash(h, c) ((((h) >> H - 8 | (h) << 8) ^ (c)) & HSIZE - 1)
152 struct cc **cc_output; /* the output array */
153 short *cc_places[TOKEN_MAX + 1];
154 short *cc_hashcodes; /* for computing hashcodes */
155 struct cc **cc_htab; /* the hash table */
156 struct cc **cc_tokens; /* holds all the active tokens */
162 long cc_time, cc_time0;
164 char *cc_tt_ob, *cc_tt_obe;
169 register struct cc *p;
171 if (tt.tt_token_max > cc_token_max)
172 tt.tt_token_max = cc_token_max;
173 if (tt.tt_token_min < cc_token_min)
174 tt.tt_token_min = cc_token_min;
175 if (tt.tt_token_min > tt.tt_token_max) {
179 if (tt.tt_ntoken > cc_ntoken / 2) /* not likely */
180 tt.tt_ntoken = cc_ntoken / 2;
181 #define C(x) (sizeof (x) / sizeof *(x))
182 for (i = 0; i < C(cc_thresholds); i++) {
183 int h = i - tt.tt_put_token_cost;
186 (tt.tt_set_token_cost + 1 + h - 1) / h + 1;
188 cc_thresholds[i] = 0;
190 for (i = 0; i < C(cc_score_adjustments); i++) {
191 int t = cc_thresholds[i];
192 for (j = 0; j < C(*cc_score_adjustments); j++) {
194 cc_score_adjustments[i][j] =
195 - (i - tt.tt_put_token_cost);
197 cc_score_adjustments[i][j] = 0;
201 * length * (ccount + 1) a
203 * set-token-cost + length +
204 * ccount * put-token-cost b
205 * the score adjustment is (b - a)
207 cc_score_adjustments[i][j] =
208 tt.tt_set_token_cost + i +
209 j * tt.tt_put_token_cost -
212 cc_initial_scores[i][j] = 0;
215 * - (set-token-cost +
216 * (length - put-token-cost) -
217 * (length - put-token-cost) * ccount)
219 cc_initial_scores[i][j] =
220 - (tt.tt_set_token_cost +
221 (i - tt.tt_put_token_cost) -
222 (i - tt.tt_put_token_cost) * j);
226 for (i = 1; i < C(cc_wthresholds); i++) {
228 ((tt.tt_set_token_cost + tt.tt_put_token_cost) / i +
231 cc_wlimits[i] = cc_wthresholds[i] + cc_weight;
235 if ((cc_output = (struct cc **)
236 malloc((unsigned) cc_bufsize * sizeof *cc_output)) == 0)
238 if ((cc_hashcodes = (short *)
239 malloc((unsigned) cc_bufsize * sizeof *cc_hashcodes)) == 0)
241 if ((cc_htab = (struct cc **) malloc(HSIZE * sizeof *cc_htab)) == 0)
243 if ((cc_tokens = (struct cc **)
245 (cc_ntoken + tt.tt_token_max - tt.tt_token_min + 1) *
246 sizeof *cc_tokens)) == 0)
248 if ((cc_undo = (struct cc_undo *)
249 malloc((unsigned) cc_bufsize * sizeof *cc_undo)) == 0)
251 for (i = tt.tt_token_min; i <= tt.tt_token_max; i++)
252 if ((cc_places[i] = (short *)
253 malloc((unsigned) cc_bufsize * sizeof **cc_places)) == 0)
255 cc_q0a.qforw = cc_q0a.qback = &cc_q0a;
256 cc_q0b.qforw = cc_q0b.qback = &cc_q0b;
257 cc_q1a.qforw = cc_q1a.qback = &cc_q1a;
258 cc_q1b.qforw = cc_q1b.qback = &cc_q1b;
259 if ((p = (struct cc *) malloc((unsigned) cc_ntoken * sizeof *p)) == 0)
261 for (i = 0; i < tt.tt_ntoken; i++) {
264 p->qback = cc_q0a.qback;
270 for (; i < cc_ntoken; i++) {
273 p->qback = cc_q1a.qback;
281 if ((cc_buffer = malloc((unsigned) cc_bufsize)) == 0)
294 tt_obp = tt_ob = cc_buffer;
295 tt_obe = tt_ob + cc_bufsize;
296 tt.tt_flush = ccflush;
298 cc_trace_fp = fopen("window-trace", "a");
299 (void) fcntl(fileno(cc_trace_fp), F_SETFD, 1);
306 register struct cc *p;
308 bzero((char *) cc_htab, HSIZE * sizeof *cc_htab);
309 for (p = cc_q0a.qforw; p != &cc_q0a; p = p->qforw)
311 for (p = cc_q1a.qforw; p != &cc_q1a; p = p->qforw)
319 tt_obp = tt_ob = cc_tt_ob;
322 if (cc_trace_fp != NULL) {
323 (void) fclose(cc_trace_fp);
330 int bufsize = tt_obp - tt_ob;
333 if (tt_ob != cc_buffer)
335 if (cc_trace_fp != NULL) {
336 (void) fwrite(tt_ob, 1, bufsize, cc_trace_fp);
337 (void) putc(-1, cc_trace_fp);
340 (*tt.tt_compress)(1);
341 if (bufsize < tt.tt_token_min) {
345 tt_obp = tt_ob = cc_tt_ob;
349 n = cc_sweep_phase(cc_buffer, bufsize, cc_tokens);
350 cc_compress_phase(cc_output, bufsize, cc_tokens, n);
351 cc_output_phase(cc_buffer, cc_output, bufsize);
353 tt_obp = tt_ob = cc_buffer;
354 tt_obe = cc_buffer + cc_bufsize;
356 (*tt.tt_compress)(0);
357 tt.tt_flush = ccflush;
360 cc_sweep_phase(buffer, bufsize, tokens)
364 register struct cc **pp = tokens;
376 cc_sweep0(buffer, bufsize, tt.tt_token_min - 1);
382 for (i = tt.tt_token_min; i <= tt.tt_token_max; i++) {
391 (void) fflush(stdout);
394 n = cc_sweep(buffer, bufsize, pp, i);
406 qinsertq(&cc_q1b, &cc_q1a);
409 printf("\n %d tokens, %d candidates\n",
417 cc_sweep0(buffer, n, length)
424 register short pc = tt.tt_padc;
426 /* n and length are at least 1 */
431 if ((*hc++ = *p++) == pc)
437 for (i = n--; --i;) {
438 if ((c = *p++) == pc || *hc < 0)
447 cc_sweep(buffer, bufsize, tokens, length)
452 register struct cc *p;
456 short *places = cc_places[length];
457 struct cc **pp = tokens;
458 short threshold = thresh(length);
460 short wthreshold = wthresh(length);
461 short limit = wlimit(length);
464 short pc = tt.tt_padc;
471 for (i = 0; i < bufsize; i++, time++) {
475 register short *hc1 = hc;
476 register short c = *cp++;
478 if ((hh = *hc1) < 0 || c == pc) {
483 h = cc_htab + (*hc1++ = hash(hh, c));
486 for (p = *h; p != 0; p = p->hforw)
487 if (p->length == (char) length) {
488 register char *p1 = p->string;
489 register char *p2 = cp - length;
501 p->time >= cc_time0 && p->length == (char) length)
504 if ((*p->hback = p->hforw) != 0)
505 p->hforw->hback = p->hback;
507 register char *p1 = p->string;
508 register char *p2 = cp - length;
516 p->weight = cc_weight;
522 if ((p->hforw = *h) != 0)
523 p->hforw->hback = &p->hforw;
532 } else if (p->time < cc_time0) {
534 if ((p->weight += p->time - time) < 0)
535 p->weight = cc_weight;
536 else if ((p->weight += cc_weight) > limit)
547 if (p->weight >= wthreshold) {
562 } else if (p->time + length > time) {
564 * overlapping token, don't count as two and
565 * don't update time, but do adjust weight to offset
569 if (cc_weight != 0) { /* XXX */
570 p->weight += time - p->time;
571 if (!p->flag && p->weight >= wthreshold) {
578 places[i] = p->places;
582 if ((p->weight += p->time - time) < 0)
583 p->weight = cc_weight;
584 else if ((p->weight += cc_weight) > limit)
590 /* code must be < 0 if flag false here */
591 (p->bcount >= threshold
593 || p->weight >= wthreshold
600 places[i] = p->places;
604 if ((i = pp - tokens) > 0) {
607 cc_sweep_reverse(tokens, places);
608 if (cc_sort && i > 1) {
609 int cc_token_compare();
610 qsort((char *) tokens, i, sizeof *tokens,
614 if ((i = i * cc_chop / 100) == 0)
623 cc_sweep_reverse(pp, places)
624 register struct cc **pp;
625 register short *places;
627 register struct cc *p;
628 register short front, back, t;
630 while ((p = *pp++) != 0) {
633 /* the list is never empty */
638 } while ((t = front) >= 0);
643 cc_compress_phase(output, bufsize, tokens, ntoken)
649 bzero((char *) output, bufsize * sizeof *output);
650 for (i = 0; i < cc_npass0; i++)
651 cc_compress_phase1(output, tokens, ntoken, 0);
652 for (i = 0; i < cc_npass1; i++)
653 cc_compress_phase1(output, tokens, ntoken, 1);
654 cc_compress_cleanup(output, bufsize);
657 cc_compress_phase1(output, tokens, ntoken, flag)
658 register struct cc **output;
661 register struct cc **pp;
664 int nt = 0, cc = 0, nc = 0;
674 while (pp < tokens + ntoken) {
685 printf(" (%d", (*pp)->length);
686 (void) fflush(stdout);
689 pp += cc_compress(output, pp, flag);
692 printf(" %dt %du %dc)", ntoken_stat, ccount_stat,
702 printf("\n total: (%dt %du %dc)\n", nt, cc, nc);
708 cc_compress_cleanup(output, bufsize)
709 register struct cc **output;
711 register struct cc **end;
713 /* the previous output phase may have been interrupted */
714 qinsertq(&cc_q0b, &cc_q0a);
715 for (end = output + bufsize; output < end;) {
716 register struct cc *p;
718 if ((p = *output) == 0) {
724 } else if (p->code >= 0) {
727 } else if (p->ccount == 0) {
729 } else if (p->ccount >= thresh(length)
731 || wthreshp(p->weight, length)
743 cc_compress(output, tokens, flag)
748 struct cc **pp = tokens;
749 register struct cc *p = *pp++;
750 int length = p->length;
751 int threshold = thresh(length);
753 short wthreshold = wthresh(length);
755 short *places = cc_places[length];
756 int *initial_scores = cc_initial_scores[length];
757 int initial_score0 = put_token_score(length);
761 register struct cc_undo *undop;
769 if ((short) ccount >= p->bcount)
771 if (p->code >= 0 || ccount >= threshold)
774 else if (p->weight >= wthreshold)
775 /* allow one fewer match than normal */
776 /* XXX, should adjust for ccount */
777 score = - tt.tt_set_token_cost;
780 score = initial_scores[ccount];
785 for (i = p->places; i >= 0; i = places[i]) {
786 register struct cc **jp;
787 register struct cc *x;
788 register struct cc **ip = output + i;
789 register score0 = initial_score0;
790 struct cc **iip = ip + length;
791 struct cc_undo *undop1 = undop;
793 if ((x = *(jp = ip)) != 0)
795 while (--jp >= output)
796 if ((x = *jp) != 0) {
797 if (jp + x->length > ip)
803 if ((x = *jp) == 0) {
818 score_adjust(score0, x);
819 if (score0 < 0 && flag)
831 while (--undop >= undop1)
832 if (*undop->pos = x = undop->val)
838 ccount_stat += ccount - p->ccount;
840 ncover_stat += ncover;
844 register struct cc_undo *u = cc_undo;
845 while (--undop >= u) {
846 register struct cc *x;
847 if (*undop->pos = x = undop->val)
851 } while ((p = *pp++) != 0);
855 cc_output_phase(buffer, output, bufsize)
856 register char *buffer;
857 register struct cc **output;
861 register struct cc *p, *p1;
863 for (i = 0; i < bufsize;) {
864 if ((p = output[i]) == 0) {
867 } else if (p->code >= 0) {
868 if (--p->ccount == 0)
870 (*tt.tt_put_token)(p->code, p->string, p->length);
872 wwntoksave += put_token_score(p->length);
874 } else if ((p1 = cc_q0a.qback) != &cc_q0a) {
877 qinsert(p1, &cc_q1a);
878 if (--p->ccount == 0)
882 (*tt.tt_set_token)(p->code, p->string, p->length);
884 wwntoksave -= tt.tt_set_token_cost;
888 ttwrite(p->string, p->length);
896 cc_token_compare(p1, p2)
897 struct cc **p1, **p2;
899 return (*p2)->bcount - (*p1)->bcount;