usr.bin/window/compress.c

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Edward Wang at The University of California, Berkeley.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  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.
  23  *
  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
  34  * SUCH DAMAGE.
  35  *
  36  * @(#)compress.c       8.1 (Berkeley) 6/6/93
  37  * $FreeBSD: src/usr.bin/window/compress.c,v 1.2.12.1 2001/05/17 09:45:00 obrien Exp $
  38  * $DragonFly: src/usr.bin/window/compress.c,v 1.2 2003/06/17 04:29:33 dillon Exp $
  39  */
  40
  41 #include "ww.h"
  42 #include "tt.h"
  43
  44         /* special */
  45 #include <stdio.h>
  46 #include <fcntl.h>
  47 #include <stdlib.h>
  48 int cc_trace = 0;
  49 FILE *cc_trace_fp;
  50
  51         /* tunable parameters */
  52
  53 int cc_reverse = 1;
  54 int cc_sort = 0;
  55 int cc_chop = 0;
  56
  57 int cc_token_max = 8;           /* <= TOKEN_MAX */
  58 int cc_token_min = 2;           /* > tt.tt_put_token_cost */
  59 int cc_npass0 = 1;
  60 int cc_npass1 = 1;
  61
  62 int cc_bufsize = 1024 * 3;      /* XXX, or 80 * 24 * 2 */
  63
  64 int cc_ntoken = 8192;
  65
  66 #define cc_weight XXX
  67 #ifndef cc_weight
  68 int cc_weight = 0;
  69 #endif
  70
  71 #define TOKEN_MAX 16
  72
  73 struct cc {
  74         char string[TOKEN_MAX];
  75         char length;
  76         char flag;
  77 #ifndef cc_weight
  78         short weight;
  79 #endif
  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;
  87 };
  88
  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])
  93
  94 #ifndef cc_weight
  95 short cc_wthresholds[TOKEN_MAX + 1];
  96 #define wthresh(length) (cc_wthresholds[length])
  97 #define wthreshp(weight, length) ((short) (weight) >= cc_wthresholds[length])
  98 #else
  99 #define wthreshp(weight, length) (0)
 100 #endif
 101
 102 #ifndef cc_weight
 103 short cc_wlimits[TOKEN_MAX + 1];
 104 #define wlimit(length) (cc_wlimits[length])
 105 #endif
 106
 107 #define put_token_score(length) ((length) - tt.tt_put_token_cost)
 108
 109 int cc_score_adjustments[TOKEN_MAX + 1][8]; /* XXX, 8 > max of cc_thresholds */
 110 #define score_adjust(score, p) \
 111         do { \
 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; \
 117                 else \
 118                         (score) += cc_score_adjustments[length][ccount]; \
 119         } while (0)
 120
 121 int cc_initial_scores[TOKEN_MAX + 1][8]; /* XXX, 8 > max of cc_thresholds */
 122
 123 struct cc cc_q0a, cc_q0b, cc_q1a, cc_q1b;
 124
 125 #define qinsert(p1, p2) \
 126         do { \
 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); \
 136         } while (0)
 137
 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, \
 144           (q)->qforw = (q), \
 145           (q)->qback = (q)))
 146
 147 #define H               (14)
 148 #define HSIZE           (1 << H)
 149 #define hash(h, c)      ((((h) >> H - 8 | (h) << 8) ^ (c)) & HSIZE - 1)
 150
 151 char *cc_buffer;
 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 */
 157 struct cc_undo {
 158         struct cc **pos;
 159         struct cc *val;
 160 } *cc_undo;
 161
 162 long cc_time, cc_time0;
 163
 164 char *cc_tt_ob, *cc_tt_obe;
 165
 166 ccinit()
 167 {
 168         register i, j;
 169         register struct cc *p;
 170
 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) {
 176                 tt.tt_ntoken = 0;
 177                 return 0;
 178         }
 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;
 184                 if (h > 0)
 185                         cc_thresholds[i] =
 186                                 (tt.tt_set_token_cost + 1 + h - 1) / h + 1;
 187                 else
 188                         cc_thresholds[i] = 0;
 189         }
 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++) {
 193                         if (j >= t)
 194                                 cc_score_adjustments[i][j] =
 195                                         - (i - tt.tt_put_token_cost);
 196                         else if (j < t - 1)
 197                                 cc_score_adjustments[i][j] = 0;
 198                         else
 199                                 /*
 200                                  * cost now is
 201                                  *      length * (ccount + 1)           a
 202                                  * cost before was
 203                                  *      set-token-cost + length +
 204                                  *              ccount * put-token-cost b
 205                                  * the score adjustment is (b - a)
 206                                  */
 207                                 cc_score_adjustments[i][j] =
 208                                         tt.tt_set_token_cost + i +
 209                                                 j * tt.tt_put_token_cost -
 210                                                         i * (j + 1);
 211                         if (j >= t)
 212                                 cc_initial_scores[i][j] = 0;
 213                         else
 214                                 /*
 215                                  * - (set-token-cost +
 216                                  *      (length - put-token-cost) -
 217                                  *      (length - put-token-cost) * ccount)
 218                                  */
 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);
 223                 }
 224         }
 225 #ifndef cc_weight
 226         for (i = 1; i < C(cc_wthresholds); i++) {
 227                 cc_wthresholds[i] =
 228                         ((tt.tt_set_token_cost + tt.tt_put_token_cost) / i +
 229                                 i / 5 + 1) *
 230                                 cc_weight + 1;
 231                 cc_wlimits[i] = cc_wthresholds[i] + cc_weight;
 232         }
 233 #endif
 234 #undef C
 235         if ((cc_output = (struct cc **)
 236              malloc((unsigned) cc_bufsize * sizeof *cc_output)) == 0)
 237                 goto nomem;
 238         if ((cc_hashcodes = (short *)
 239              malloc((unsigned) cc_bufsize * sizeof *cc_hashcodes)) == 0)
 240                 goto nomem;
 241         if ((cc_htab = (struct cc **) malloc(HSIZE * sizeof *cc_htab)) == 0)
 242                 goto nomem;
 243         if ((cc_tokens = (struct cc **)
 244              malloc((unsigned)
 245                     (cc_ntoken + tt.tt_token_max - tt.tt_token_min + 1) *
 246                     sizeof *cc_tokens)) == 0)
 247                 goto nomem;
 248         if ((cc_undo = (struct cc_undo *)
 249              malloc((unsigned) cc_bufsize * sizeof *cc_undo)) == 0)
 250                 goto nomem;
 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)
 254                         goto nomem;
 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)
 260                 goto nomem;
 261         for (i = 0; i < tt.tt_ntoken; i++) {
 262                 p->code = i;
 263                 p->time = -1;
 264                 p->qback = cc_q0a.qback;
 265                 p->qforw = &cc_q0a;
 266                 p->qback->qforw = p;
 267                 cc_q0a.qback = p;
 268                 p++;
 269         }
 270         for (; i < cc_ntoken; i++) {
 271                 p->code = -1;
 272                 p->time = -1;
 273                 p->qback = cc_q1a.qback;
 274                 p->qforw = &cc_q1a;
 275                 p->qback->qforw = p;
 276                 cc_q1a.qback = p;
 277                 p++;
 278         }
 279         cc_tt_ob = tt_ob;
 280         cc_tt_obe = tt_obe;
 281         if ((cc_buffer = malloc((unsigned) cc_bufsize)) == 0)
 282                 goto nomem;
 283         return 0;
 284 nomem:
 285         wwerrno = WWE_NOMEM;
 286         return -1;
 287 }
 288
 289 ccstart()
 290 {
 291         int ccflush();
 292
 293         ttflush();
 294         tt_obp = tt_ob = cc_buffer;
 295         tt_obe = tt_ob + cc_bufsize;
 296         tt.tt_flush = ccflush;
 297         if (cc_trace) {
 298                 cc_trace_fp = fopen("window-trace", "a");
 299                 (void) fcntl(fileno(cc_trace_fp), F_SETFD, 1);
 300         }
 301         ccreset();
 302 }
 303
 304 ccreset()
 305 {
 306         register struct cc *p;
 307
 308         bzero((char *) cc_htab, HSIZE * sizeof *cc_htab);
 309         for (p = cc_q0a.qforw; p != &cc_q0a; p = p->qforw)
 310                 p->hback = 0;
 311         for (p = cc_q1a.qforw; p != &cc_q1a; p = p->qforw)
 312                 p->hback = 0;
 313 }
 314
 315 ccend()
 316 {
 317
 318         ttflush();
 319         tt_obp = tt_ob = cc_tt_ob;
 320         tt_obe = cc_tt_obe;
 321         tt.tt_flush = 0;
 322         if (cc_trace_fp != NULL) {
 323                 (void) fclose(cc_trace_fp);
 324                 cc_trace_fp = NULL;
 325         }
 326 }
 327
 328 ccflush()
 329 {
 330         int bufsize = tt_obp - tt_ob;
 331         int n;
 332
 333         if (tt_ob != cc_buffer)
 334                 abort();
 335         if (cc_trace_fp != NULL) {
 336                 (void) fwrite(tt_ob, 1, bufsize, cc_trace_fp);
 337                 (void) putc(-1, cc_trace_fp);
 338         }
 339         tt.tt_flush = 0;
 340         (*tt.tt_compress)(1);
 341         if (bufsize < tt.tt_token_min) {
 342                 ttflush();
 343                 goto out;
 344         }
 345         tt_obp = tt_ob = cc_tt_ob;
 346         tt_obe = cc_tt_obe;
 347         cc_time0 = cc_time;
 348         cc_time += bufsize;
 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);
 352         ttflush();
 353         tt_obp = tt_ob = cc_buffer;
 354         tt_obe = cc_buffer + cc_bufsize;
 355 out:
 356         (*tt.tt_compress)(0);
 357         tt.tt_flush = ccflush;
 358 }
 359
 360 cc_sweep_phase(buffer, bufsize, tokens)
 361         char *buffer;
 362         struct cc **tokens;
 363 {
 364         register struct cc **pp = tokens;
 365         register i, n;
 366 #ifdef STATS
 367         int nn, ii;
 368 #endif
 369
 370 #ifdef STATS
 371         if (verbose >= 0)
 372                 time_begin();
 373         if (verbose > 0)
 374                 printf("Sweep:");
 375 #endif
 376         cc_sweep0(buffer, bufsize, tt.tt_token_min - 1);
 377 #ifdef STATS
 378         ntoken_stat = 0;
 379         nn = 0;
 380         ii = 0;
 381 #endif
 382         for (i = tt.tt_token_min; i <= tt.tt_token_max; i++) {
 383 #ifdef STATS
 384                 if (verbose > 0) {
 385                         if (ii > 7) {
 386                                 printf("\n      ");
 387                                 ii = 0;
 388                         }
 389                         ii++;
 390                         printf(" (%d", i);
 391                         (void) fflush(stdout);
 392                 }
 393 #endif
 394                 n = cc_sweep(buffer, bufsize, pp, i);
 395                 pp += n;
 396 #ifdef STATS
 397                 if (verbose > 0) {
 398                         if (--n > 0) {
 399                                 printf(" %d", n);
 400                                 nn += n;
 401                         }
 402                         putchar(')');
 403                 }
 404 #endif
 405         }
 406         qinsertq(&cc_q1b, &cc_q1a);
 407 #ifdef STATS
 408         if (verbose > 0)
 409                 printf("\n       %d tokens, %d candidates\n",
 410                         ntoken_stat, nn);
 411         if (verbose >= 0)
 412                 time_end();
 413 #endif
 414         return pp - tokens;
 415 }
 416
 417 cc_sweep0(buffer, n, length)
 418         char *buffer;
 419 {
 420         register char *p;
 421         register short *hc;
 422         register i;
 423         register short c;
 424         register short pc = tt.tt_padc;
 425
 426         /* n and length are at least 1 */
 427         p = buffer++;
 428         hc = cc_hashcodes;
 429         i = n;
 430         do {
 431                 if ((*hc++ = *p++) == pc)
 432                         hc[-1] = -1;
 433         } while (--i);
 434         while (--length) {
 435                 p = buffer++;
 436                 hc = cc_hashcodes;
 437                 for (i = n--; --i;) {
 438                         if ((c = *p++) == pc || *hc < 0)
 439                                 c = -1;
 440                         else
 441                                 c = hash(*hc, c);
 442                         *hc++ = c;
 443                 }
 444         }
 445 }
 446
 447 cc_sweep(buffer, bufsize, tokens, length)
 448         char *buffer;
 449         struct cc **tokens;
 450         register length;
 451 {
 452         register struct cc *p;
 453         register char *cp;
 454         register i;
 455         short *hc;
 456         short *places = cc_places[length];
 457         struct cc **pp = tokens;
 458         short threshold = thresh(length);
 459 #ifndef cc_weight
 460         short wthreshold = wthresh(length);
 461         short limit = wlimit(length);
 462 #endif
 463         int time;
 464         short pc = tt.tt_padc;
 465
 466         i = length - 1;
 467         bufsize -= i;
 468         cp = buffer + i;
 469         hc = cc_hashcodes;
 470         time = cc_time0;
 471         for (i = 0; i < bufsize; i++, time++) {
 472                 struct cc **h;
 473
 474                 {
 475                         register short *hc1 = hc;
 476                         register short c = *cp++;
 477                         register short hh;
 478                         if ((hh = *hc1) < 0 || c == pc) {
 479                                 *hc1++ = -1;
 480                                 hc = hc1;
 481                                 continue;
 482                         }
 483                         h = cc_htab + (*hc1++ = hash(hh, c));
 484                         hc = hc1;
 485                 }
 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;
 490                                 register n = length;
 491                                 do
 492                                         if (*p1++ != *p2++)
 493                                                 goto fail;
 494                                 while (--n);
 495                                 break;
 496                         fail:;
 497                         }
 498                 if (p == 0) {
 499                         p = cc_q1a.qback;
 500                         if (p == &cc_q1a ||
 501                             p->time >= cc_time0 && p->length == (char) length)
 502                                 continue;
 503                         if (p->hback != 0)
 504                                 if ((*p->hback = p->hforw) != 0)
 505                                         p->hforw->hback = p->hback;
 506                         {
 507                                 register char *p1 = p->string;
 508                                 register char *p2 = cp - length;
 509                                 register n = length;
 510                                 do
 511                                         *p1++ = *p2++;
 512                                 while (--n);
 513                         }
 514                         p->length = length;
 515 #ifndef cc_weight
 516                         p->weight = cc_weight;
 517 #endif
 518                         p->time = time;
 519                         p->bcount = 1;
 520                         p->ccount = 0;
 521                         p->flag = 0;
 522                         if ((p->hforw = *h) != 0)
 523                                 p->hforw->hback = &p->hforw;
 524                         *h = p;
 525                         p->hback = h;
 526                         qinsert(p, &cc_q1a);
 527                         places[i] = -1;
 528                         p->places = i;
 529 #ifdef STATS
 530                         ntoken_stat++;
 531 #endif
 532                 } else if (p->time < cc_time0) {
 533 #ifndef cc_weight
 534                         if ((p->weight += p->time - time) < 0)
 535                                 p->weight = cc_weight;
 536                         else if ((p->weight += cc_weight) > limit)
 537                                 p->weight = limit;
 538 #endif
 539                         p->time = time;
 540                         p->bcount = 1;
 541                         p->ccount = 0;
 542                         if (p->code >= 0) {
 543                                 p->flag = 1;
 544                                 *pp++ = p;
 545                         } else
 546 #ifndef cc_weight
 547                         if (p->weight >= wthreshold) {
 548                                 p->flag = 1;
 549                                 *pp++ = p;
 550                                 qinsert(p, &cc_q1b);
 551                         } else
 552 #endif
 553                         {
 554                                 p->flag = 0;
 555                                 qinsert(p, &cc_q1a);
 556                         }
 557                         places[i] = -1;
 558                         p->places = i;
 559 #ifdef STATS
 560                         ntoken_stat++;
 561 #endif
 562                 } else if (p->time + length > time) {
 563                         /*
 564                          * overlapping token, don't count as two and
 565                          * don't update time, but do adjust weight to offset
 566                          * the difference
 567                          */
 568 #ifndef cc_weight
 569                         if (cc_weight != 0) {   /* XXX */
 570                                 p->weight += time - p->time;
 571                                 if (!p->flag && p->weight >= wthreshold) {
 572                                         p->flag = 1;
 573                                         *pp++ = p;
 574                                         qinsert(p, &cc_q1b);
 575                                 }
 576                         }
 577 #endif
 578                         places[i] = p->places;
 579                         p->places = i;
 580                 } else {
 581 #ifndef cc_weight
 582                         if ((p->weight += p->time - time) < 0)
 583                                 p->weight = cc_weight;
 584                         else if ((p->weight += cc_weight) > limit)
 585                                 p->weight = limit;
 586 #endif
 587                         p->time = time;
 588                         p->bcount++;
 589                         if (!p->flag &&
 590                             /* code must be < 0 if flag false here */
 591                             (p->bcount >= threshold
 592 #ifndef cc_weight
 593                              || p->weight >= wthreshold
 594 #endif
 595                              )) {
 596                                 p->flag = 1;
 597                                 *pp++ = p;
 598                                 qinsert(p, &cc_q1b);
 599                         }
 600                         places[i] = p->places;
 601                         p->places = i;
 602                 }
 603         }
 604         if ((i = pp - tokens) > 0) {
 605                 *pp = 0;
 606                 if (cc_reverse)
 607                         cc_sweep_reverse(tokens, places);
 608                 if (cc_sort && i > 1) {
 609                         int cc_token_compare();
 610                         qsort((char *) tokens, i, sizeof *tokens,
 611                               cc_token_compare);
 612                 }
 613                 if (cc_chop) {
 614                         if ((i = i * cc_chop / 100) == 0)
 615                                 i = 1;
 616                         tokens[i] = 0;
 617                 }
 618                 i++;
 619         }
 620         return i;
 621 }
 622
 623 cc_sweep_reverse(pp, places)
 624         register struct cc **pp;
 625         register short *places;
 626 {
 627         register struct cc *p;
 628         register short front, back, t;
 629
 630         while ((p = *pp++) != 0) {
 631                 back = -1;
 632                 t = p->places;
 633                 /* the list is never empty */
 634                 do {
 635                         front = places[t];
 636                         places[t] = back;
 637                         back = t;
 638                 } while ((t = front) >= 0);
 639                 p->places = back;
 640         }
 641 }
 642
 643 cc_compress_phase(output, bufsize, tokens, ntoken)
 644         struct cc **output;
 645         struct cc **tokens;
 646 {
 647         register i;
 648
 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);
 655 }
 656
 657 cc_compress_phase1(output, tokens, ntoken, flag)
 658         register struct cc **output;
 659         struct cc **tokens;
 660 {
 661         register struct cc **pp;
 662 #ifdef STATS
 663         register int i = 0;
 664         int nt = 0, cc = 0, nc = 0;
 665 #endif
 666
 667 #ifdef STATS
 668         if (verbose >= 0)
 669                 time_begin();
 670         if (verbose > 0)
 671                 printf("Compress:");
 672 #endif
 673         pp = tokens;
 674         while (pp < tokens + ntoken) {
 675 #ifdef STATS
 676                 if (verbose > 0) {
 677                         ntoken_stat = 0;
 678                         ccount_stat = 0;
 679                         ncover_stat = 0;
 680                         if (i > 2) {
 681                                 printf("\n         ");
 682                                 i = 0;
 683                         }
 684                         i++;
 685                         printf(" (%d", (*pp)->length);
 686                         (void) fflush(stdout);
 687                 }
 688 #endif
 689                 pp += cc_compress(output, pp, flag);
 690 #ifdef STATS
 691                 if (verbose > 0) {
 692                         printf(" %dt %du %dc)", ntoken_stat, ccount_stat,
 693                                ncover_stat);
 694                         nt += ntoken_stat;
 695                         cc += ccount_stat;
 696                         nc += ncover_stat;
 697                 }
 698 #endif
 699         }
 700 #ifdef STATS
 701         if (verbose > 0)
 702                 printf("\n   total: (%dt %du %dc)\n", nt, cc, nc);
 703         if (verbose >= 0)
 704                 time_end();
 705 #endif
 706 }
 707
 708 cc_compress_cleanup(output, bufsize)
 709         register struct cc **output;
 710 {
 711         register struct cc **end;
 712
 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;
 717                 register length;
 718                 if ((p = *output) == 0) {
 719                         output++;
 720                         continue;
 721                 }
 722                 length = p->length;
 723                 if (!p->flag) {
 724                 } else if (p->code >= 0) {
 725                         qinsert(p, &cc_q0b);
 726                         p->flag = 0;
 727                 } else if (p->ccount == 0) {
 728                         *output = 0;
 729                 } else if (p->ccount >= thresh(length)
 730 #ifndef cc_weight
 731                            || wthreshp(p->weight, length)
 732 #endif
 733                            ) {
 734                         p->flag = 0;
 735                 } else {
 736                         p->ccount = 0;
 737                         *output = 0;
 738                 }
 739                 output += length;
 740         }
 741 }
 742
 743 cc_compress(output, tokens, flag)
 744         struct cc **output;
 745         struct cc **tokens;
 746         char flag;
 747 {
 748         struct cc **pp = tokens;
 749         register struct cc *p = *pp++;
 750         int length = p->length;
 751         int threshold = thresh(length);
 752 #ifndef cc_weight
 753         short wthreshold = wthresh(length);
 754 #endif
 755         short *places = cc_places[length];
 756         int *initial_scores = cc_initial_scores[length];
 757         int initial_score0 = put_token_score(length);
 758
 759         do {
 760                 int score;
 761                 register struct cc_undo *undop;
 762                 int ccount;
 763 #ifdef STATS
 764                 int ncover;
 765 #endif
 766                 int i;
 767
 768                 ccount = p->ccount;
 769                 if ((short) ccount >= p->bcount)
 770                         continue;
 771                 if (p->code >= 0 || ccount >= threshold)
 772                         score = 0;
 773 #ifndef cc_weight
 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;
 778 #endif
 779                 else
 780                         score = initial_scores[ccount];
 781                 undop = cc_undo;
 782 #ifdef STATS
 783                 ncover = 0;
 784 #endif
 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;
 792
 793                         if ((x = *(jp = ip)) != 0)
 794                                 goto z;
 795                         while (--jp >= output)
 796                                 if ((x = *jp) != 0) {
 797                                         if (jp + x->length > ip)
 798                                                 goto z;
 799                                         break;
 800                                 }
 801                         jp = ip + 1;
 802                         while (jp < iip) {
 803                                 if ((x = *jp) == 0) {
 804                                         jp++;
 805                                         continue;
 806                                 }
 807                         z:
 808                                 if (x == p)
 809                                         goto undo;
 810 #ifdef STATS
 811                                 ncover++;
 812 #endif
 813                                 undop->pos = jp;
 814                                 undop->val = x;
 815                                 undop++;
 816                                 *jp = 0;
 817                                 x->ccount--;
 818                                 score_adjust(score0, x);
 819                                 if (score0 < 0 && flag)
 820                                         goto undo;
 821                                 jp += x->length;
 822                         }
 823                         undop->pos = ip;
 824                         undop->val = 0;
 825                         undop++;
 826                         *ip = p;
 827                         ccount++;
 828                         score += score0;
 829                         continue;
 830                 undo:
 831                         while (--undop >= undop1)
 832                                 if (*undop->pos = x = undop->val)
 833                                         x->ccount++;
 834                         undop++;
 835                 }
 836                 if (score > 0) {
 837 #ifdef STATS
 838                         ccount_stat += ccount - p->ccount;
 839                         ntoken_stat++;
 840                         ncover_stat += ncover;
 841 #endif
 842                         p->ccount = ccount;
 843                 } else {
 844                         register struct cc_undo *u = cc_undo;
 845                         while (--undop >= u) {
 846                                 register struct cc *x;
 847                                 if (*undop->pos = x = undop->val)
 848                                         x->ccount++;
 849                         }
 850                 }
 851         } while ((p = *pp++) != 0);
 852         return pp - tokens;
 853 }
 854
 855 cc_output_phase(buffer, output, bufsize)
 856         register char *buffer;
 857         register struct cc **output;
 858         register bufsize;
 859 {
 860         register i;
 861         register struct cc *p, *p1;
 862
 863         for (i = 0; i < bufsize;) {
 864                 if ((p = output[i]) == 0) {
 865                         ttputc(buffer[i]);
 866                         i++;
 867                 } else if (p->code >= 0) {
 868                         if (--p->ccount == 0)
 869                                 qinsert(p, &cc_q0a);
 870                         (*tt.tt_put_token)(p->code, p->string, p->length);
 871                         wwntokuse++;
 872                         wwntoksave += put_token_score(p->length);
 873                         i += p->length;
 874                 } else if ((p1 = cc_q0a.qback) != &cc_q0a) {
 875                         p->code = p1->code;
 876                         p1->code = -1;
 877                         qinsert(p1, &cc_q1a);
 878                         if (--p->ccount == 0)
 879                                 qinsert(p, &cc_q0a);
 880                         else
 881                                 qinsert(p, &cc_q0b);
 882                         (*tt.tt_set_token)(p->code, p->string, p->length);
 883                         wwntokdef++;
 884                         wwntoksave -= tt.tt_set_token_cost;
 885                         i += p->length;
 886                 } else {
 887                         p->ccount--;
 888                         ttwrite(p->string, p->length);
 889                         wwntokbad++;
 890                         i += p->length;
 891                 }
 892         }
 893         wwntokc += bufsize;
 894 }
 895
 896 cc_token_compare(p1, p2)
 897         struct cc **p1, **p2;
 898 {
 899         return (*p2)->bcount - (*p1)->bcount;
 900 }