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1.1 ! root 1: /* trees.c -- output deflated data using Huffman coding ! 2: * Copyright (C) 1992-1993 Jean-loup Gailly ! 3: * This is free software; you can redistribute it and/or modify it under the ! 4: * terms of the GNU General Public License, see the file COPYING. ! 5: */ ! 6: ! 7: /* ! 8: * PURPOSE ! 9: * ! 10: * Encode various sets of source values using variable-length ! 11: * binary code trees. ! 12: * ! 13: * DISCUSSION ! 14: * ! 15: * The PKZIP "deflation" process uses several Huffman trees. The more ! 16: * common source values are represented by shorter bit sequences. ! 17: * ! 18: * Each code tree is stored in the ZIP file in a compressed form ! 19: * which is itself a Huffman encoding of the lengths of ! 20: * all the code strings (in ascending order by source values). ! 21: * The actual code strings are reconstructed from the lengths in ! 22: * the UNZIP process, as described in the "application note" ! 23: * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program. ! 24: * ! 25: * REFERENCES ! 26: * ! 27: * Lynch, Thomas J. ! 28: * Data Compression: Techniques and Applications, pp. 53-55. ! 29: * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7. ! 30: * ! 31: * Storer, James A. ! 32: * Data Compression: Methods and Theory, pp. 49-50. ! 33: * Computer Science Press, 1988. ISBN 0-7167-8156-5. ! 34: * ! 35: * Sedgewick, R. ! 36: * Algorithms, p290. ! 37: * Addison-Wesley, 1983. ISBN 0-201-06672-6. ! 38: * ! 39: * INTERFACE ! 40: * ! 41: * void ct_init (ush *attr, int *methodp) ! 42: * Allocate the match buffer, initialize the various tables and save ! 43: * the location of the internal file attribute (ascii/binary) and ! 44: * method (DEFLATE/STORE) ! 45: * ! 46: * void ct_tally (int dist, int lc); ! 47: * Save the match info and tally the frequency counts. ! 48: * ! 49: * long flush_block (char *buf, ulg stored_len, int eof) ! 50: * Determine the best encoding for the current block: dynamic trees, ! 51: * static trees or store, and output the encoded block to the zip ! 52: * file. Returns the total compressed length for the file so far. ! 53: * ! 54: */ ! 55: ! 56: #include "tailor.h" ! 57: #include "gzip.h" ! 58: ! 59: #include <ctype.h> ! 60: #include <stdio.h> ! 61: ! 62: #ifndef lint ! 63: static char rcsid[] = "$Id: trees.c,v 0.9 1993/02/10 16:07:22 jloup Exp $"; ! 64: #endif ! 65: ! 66: /* =========================================================================== ! 67: * Constants ! 68: */ ! 69: ! 70: #define MAX_BITS 15 ! 71: /* All codes must not exceed MAX_BITS bits */ ! 72: ! 73: #define MAX_BL_BITS 7 ! 74: /* Bit length codes must not exceed MAX_BL_BITS bits */ ! 75: ! 76: #define LENGTH_CODES 29 ! 77: /* number of length codes, not counting the special END_BLOCK code */ ! 78: ! 79: #define LITERALS 256 ! 80: /* number of literal bytes 0..255 */ ! 81: ! 82: #define END_BLOCK 256 ! 83: /* end of block literal code */ ! 84: ! 85: #define L_CODES (LITERALS+1+LENGTH_CODES) ! 86: /* number of Literal or Length codes, including the END_BLOCK code */ ! 87: ! 88: #define D_CODES 30 ! 89: /* number of distance codes */ ! 90: ! 91: #define BL_CODES 19 ! 92: /* number of codes used to transfer the bit lengths */ ! 93: ! 94: ! 95: local int near extra_lbits[LENGTH_CODES] /* extra bits for each length code */ ! 96: = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0}; ! 97: ! 98: local int near extra_dbits[D_CODES] /* extra bits for each distance code */ ! 99: = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13}; ! 100: ! 101: local int near extra_blbits[BL_CODES]/* extra bits for each bit length code */ ! 102: = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; ! 103: ! 104: #define STORED_BLOCK 0 ! 105: #define STATIC_TREES 1 ! 106: #define DYN_TREES 2 ! 107: /* The three kinds of block type */ ! 108: ! 109: #ifndef LIT_BUFSIZE ! 110: # ifdef SMALL_MEM ! 111: # define LIT_BUFSIZE 0x2000 ! 112: # else ! 113: # ifdef MEDIUM_MEM ! 114: # define LIT_BUFSIZE 0x4000 ! 115: # else ! 116: # define LIT_BUFSIZE 0x8000 ! 117: # endif ! 118: # endif ! 119: #endif ! 120: #ifndef DIST_BUFSIZE ! 121: # define DIST_BUFSIZE LIT_BUFSIZE ! 122: #endif ! 123: /* Sizes of match buffers for literals/lengths and distances. There are ! 124: * 4 reasons for limiting LIT_BUFSIZE to 64K: ! 125: * - frequencies can be kept in 16 bit counters ! 126: * - if compression is not successful for the first block, all input data is ! 127: * still in the window so we can still emit a stored block even when input ! 128: * comes from standard input. (This can also be done for all blocks if ! 129: * LIT_BUFSIZE is not greater than 32K.) ! 130: * - if compression is not successful for a file smaller than 64K, we can ! 131: * even emit a stored file instead of a stored block (saving 5 bytes). ! 132: * - creating new Huffman trees less frequently may not provide fast ! 133: * adaptation to changes in the input data statistics. (Take for ! 134: * example a binary file with poorly compressible code followed by ! 135: * a highly compressible string table.) Smaller buffer sizes give ! 136: * fast adaptation but have of course the overhead of transmitting trees ! 137: * more frequently. ! 138: * - I can't count above 4 ! 139: * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save ! 140: * memory at the expense of compression). Some optimizations would be possible ! 141: * if we rely on DIST_BUFSIZE == LIT_BUFSIZE. ! 142: */ ! 143: #if LIT_BUFSIZE > INBUFSIZ ! 144: error cannot overlay l_buf and inbuf ! 145: #endif ! 146: ! 147: #define REP_3_6 16 ! 148: /* repeat previous bit length 3-6 times (2 bits of repeat count) */ ! 149: ! 150: #define REPZ_3_10 17 ! 151: /* repeat a zero length 3-10 times (3 bits of repeat count) */ ! 152: ! 153: #define REPZ_11_138 18 ! 154: /* repeat a zero length 11-138 times (7 bits of repeat count) */ ! 155: ! 156: /* =========================================================================== ! 157: * Local data ! 158: */ ! 159: ! 160: /* Data structure describing a single value and its code string. */ ! 161: typedef struct ct_data { ! 162: union { ! 163: ush freq; /* frequency count */ ! 164: ush code; /* bit string */ ! 165: } fc; ! 166: union { ! 167: ush dad; /* father node in Huffman tree */ ! 168: ush len; /* length of bit string */ ! 169: } dl; ! 170: } ct_data; ! 171: ! 172: #define Freq fc.freq ! 173: #define Code fc.code ! 174: #define Dad dl.dad ! 175: #define Len dl.len ! 176: ! 177: #define HEAP_SIZE (2*L_CODES+1) ! 178: /* maximum heap size */ ! 179: ! 180: local ct_data near dyn_ltree[HEAP_SIZE]; /* literal and length tree */ ! 181: local ct_data near dyn_dtree[2*D_CODES+1]; /* distance tree */ ! 182: ! 183: local ct_data near static_ltree[L_CODES+2]; ! 184: /* The static literal tree. Since the bit lengths are imposed, there is no ! 185: * need for the L_CODES extra codes used during heap construction. However ! 186: * The codes 286 and 287 are needed to build a canonical tree (see ct_init ! 187: * below). ! 188: */ ! 189: ! 190: local ct_data near static_dtree[D_CODES]; ! 191: /* The static distance tree. (Actually a trivial tree since all codes use ! 192: * 5 bits.) ! 193: */ ! 194: ! 195: local ct_data near bl_tree[2*BL_CODES+1]; ! 196: /* Huffman tree for the bit lengths */ ! 197: ! 198: typedef struct tree_desc { ! 199: ct_data near *dyn_tree; /* the dynamic tree */ ! 200: ct_data near *static_tree; /* corresponding static tree or NULL */ ! 201: int near *extra_bits; /* extra bits for each code or NULL */ ! 202: int extra_base; /* base index for extra_bits */ ! 203: int elems; /* max number of elements in the tree */ ! 204: int max_length; /* max bit length for the codes */ ! 205: int max_code; /* largest code with non zero frequency */ ! 206: } tree_desc; ! 207: ! 208: local tree_desc near l_desc = ! 209: {dyn_ltree, static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS, 0}; ! 210: ! 211: local tree_desc near d_desc = ! 212: {dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0}; ! 213: ! 214: local tree_desc near bl_desc = ! 215: {bl_tree, (ct_data near *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS, 0}; ! 216: ! 217: ! 218: local ush near bl_count[MAX_BITS+1]; ! 219: /* number of codes at each bit length for an optimal tree */ ! 220: ! 221: local uch near bl_order[BL_CODES] ! 222: = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; ! 223: /* The lengths of the bit length codes are sent in order of decreasing ! 224: * probability, to avoid transmitting the lengths for unused bit length codes. ! 225: */ ! 226: ! 227: local int near heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ ! 228: local int heap_len; /* number of elements in the heap */ ! 229: local int heap_max; /* element of largest frequency */ ! 230: /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. ! 231: * The same heap array is used to build all trees. ! 232: */ ! 233: ! 234: local uch near depth[2*L_CODES+1]; ! 235: /* Depth of each subtree used as tie breaker for trees of equal frequency */ ! 236: ! 237: local uch length_code[MAX_MATCH-MIN_MATCH+1]; ! 238: /* length code for each normalized match length (0 == MIN_MATCH) */ ! 239: ! 240: local uch dist_code[512]; ! 241: /* distance codes. The first 256 values correspond to the distances ! 242: * 3 .. 258, the last 256 values correspond to the top 8 bits of ! 243: * the 15 bit distances. ! 244: */ ! 245: ! 246: local int near base_length[LENGTH_CODES]; ! 247: /* First normalized length for each code (0 = MIN_MATCH) */ ! 248: ! 249: local int near base_dist[D_CODES]; ! 250: /* First normalized distance for each code (0 = distance of 1) */ ! 251: ! 252: #define l_buf inbuf ! 253: /* DECLARE(uch, l_buf, LIT_BUFSIZE); buffer for literals or lengths */ ! 254: ! 255: /* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */ ! 256: ! 257: local uch near flag_buf[(LIT_BUFSIZE/8)]; ! 258: /* flag_buf is a bit array distinguishing literals from lengths in ! 259: * l_buf, thus indicating the presence or absence of a distance. ! 260: */ ! 261: ! 262: local unsigned last_lit; /* running index in l_buf */ ! 263: local unsigned last_dist; /* running index in d_buf */ ! 264: local unsigned last_flags; /* running index in flag_buf */ ! 265: local uch flags; /* current flags not yet saved in flag_buf */ ! 266: local uch flag_bit; /* current bit used in flags */ ! 267: /* bits are filled in flags starting at bit 0 (least significant). ! 268: * Note: these flags are overkill in the current code since we don't ! 269: * take advantage of DIST_BUFSIZE == LIT_BUFSIZE. ! 270: */ ! 271: ! 272: local ulg opt_len; /* bit length of current block with optimal trees */ ! 273: local ulg static_len; /* bit length of current block with static trees */ ! 274: ! 275: local ulg compressed_len; /* total bit length of compressed file */ ! 276: ! 277: local ulg input_len; /* total byte length of input file */ ! 278: /* input_len is for debugging only since we can get it by other means. */ ! 279: ! 280: ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */ ! 281: int *file_method; /* pointer to DEFLATE or STORE */ ! 282: ! 283: #ifdef DEBUG ! 284: extern ulg bits_sent; /* bit length of the compressed data */ ! 285: extern long isize; /* byte length of input file */ ! 286: #endif ! 287: ! 288: extern long block_start; /* window offset of current block */ ! 289: extern unsigned near strstart; /* window offset of current string */ ! 290: ! 291: /* =========================================================================== ! 292: * Local (static) routines in this file. ! 293: */ ! 294: ! 295: local void init_block OF((void)); ! 296: local void pqdownheap OF((ct_data near *tree, int k)); ! 297: local void gen_bitlen OF((tree_desc near *desc)); ! 298: local void gen_codes OF((ct_data near *tree, int max_code)); ! 299: local void build_tree OF((tree_desc near *desc)); ! 300: local void scan_tree OF((ct_data near *tree, int max_code)); ! 301: local void send_tree OF((ct_data near *tree, int max_code)); ! 302: local int build_bl_tree OF((void)); ! 303: local void send_all_trees OF((int lcodes, int dcodes, int blcodes)); ! 304: local void compress_block OF((ct_data near *ltree, ct_data near *dtree)); ! 305: local void set_file_type OF((void)); ! 306: ! 307: ! 308: #ifndef DEBUG ! 309: # define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len) ! 310: /* Send a code of the given tree. c and tree must not have side effects */ ! 311: ! 312: #else /* DEBUG */ ! 313: # define send_code(c, tree) \ ! 314: { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \ ! 315: send_bits(tree[c].Code, tree[c].Len); } ! 316: #endif ! 317: ! 318: #define d_code(dist) \ ! 319: ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) ! 320: /* Mapping from a distance to a distance code. dist is the distance - 1 and ! 321: * must not have side effects. dist_code[256] and dist_code[257] are never ! 322: * used. ! 323: */ ! 324: ! 325: #define MAX(a,b) (a >= b ? a : b) ! 326: /* the arguments must not have side effects */ ! 327: ! 328: /* =========================================================================== ! 329: * Allocate the match buffer, initialize the various tables and save the ! 330: * location of the internal file attribute (ascii/binary) and method ! 331: * (DEFLATE/STORE). ! 332: */ ! 333: void ct_init(attr, methodp) ! 334: ush *attr; /* pointer to internal file attribute */ ! 335: int *methodp; /* pointer to compression method */ ! 336: { ! 337: int n; /* iterates over tree elements */ ! 338: int bits; /* bit counter */ ! 339: int length; /* length value */ ! 340: int code; /* code value */ ! 341: int dist; /* distance index */ ! 342: ! 343: file_type = attr; ! 344: file_method = methodp; ! 345: compressed_len = input_len = 0L; ! 346: ! 347: if (static_dtree[0].Len != 0) return; /* ct_init already called */ ! 348: ! 349: /* Initialize the mapping length (0..255) -> length code (0..28) */ ! 350: length = 0; ! 351: for (code = 0; code < LENGTH_CODES-1; code++) { ! 352: base_length[code] = length; ! 353: for (n = 0; n < (1<<extra_lbits[code]); n++) { ! 354: length_code[length++] = (uch)code; ! 355: } ! 356: } ! 357: Assert (length == 256, "ct_init: length != 256"); ! 358: /* Note that the length 255 (match length 258) can be represented ! 359: * in two different ways: code 284 + 5 bits or code 285, so we ! 360: * overwrite length_code[255] to use the best encoding: ! 361: */ ! 362: length_code[length-1] = (uch)code; ! 363: ! 364: /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ ! 365: dist = 0; ! 366: for (code = 0 ; code < 16; code++) { ! 367: base_dist[code] = dist; ! 368: for (n = 0; n < (1<<extra_dbits[code]); n++) { ! 369: dist_code[dist++] = (uch)code; ! 370: } ! 371: } ! 372: Assert (dist == 256, "ct_init: dist != 256"); ! 373: dist >>= 7; /* from now on, all distances are divided by 128 */ ! 374: for ( ; code < D_CODES; code++) { ! 375: base_dist[code] = dist << 7; ! 376: for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { ! 377: dist_code[256 + dist++] = (uch)code; ! 378: } ! 379: } ! 380: Assert (dist == 256, "ct_init: 256+dist != 512"); ! 381: ! 382: /* Construct the codes of the static literal tree */ ! 383: for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; ! 384: n = 0; ! 385: while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; ! 386: while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; ! 387: while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; ! 388: while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; ! 389: /* Codes 286 and 287 do not exist, but we must include them in the ! 390: * tree construction to get a canonical Huffman tree (longest code ! 391: * all ones) ! 392: */ ! 393: gen_codes((ct_data near *)static_ltree, L_CODES+1); ! 394: ! 395: /* The static distance tree is trivial: */ ! 396: for (n = 0; n < D_CODES; n++) { ! 397: static_dtree[n].Len = 5; ! 398: static_dtree[n].Code = bi_reverse(n, 5); ! 399: } ! 400: ! 401: /* Initialize the first block of the first file: */ ! 402: init_block(); ! 403: } ! 404: ! 405: /* =========================================================================== ! 406: * Initialize a new block. ! 407: */ ! 408: local void init_block() ! 409: { ! 410: int n; /* iterates over tree elements */ ! 411: ! 412: /* Initialize the trees. */ ! 413: for (n = 0; n < L_CODES; n++) dyn_ltree[n].Freq = 0; ! 414: for (n = 0; n < D_CODES; n++) dyn_dtree[n].Freq = 0; ! 415: for (n = 0; n < BL_CODES; n++) bl_tree[n].Freq = 0; ! 416: ! 417: dyn_ltree[END_BLOCK].Freq = 1; ! 418: opt_len = static_len = 0L; ! 419: last_lit = last_dist = last_flags = 0; ! 420: flags = 0; flag_bit = 1; ! 421: } ! 422: ! 423: #define SMALLEST 1 ! 424: /* Index within the heap array of least frequent node in the Huffman tree */ ! 425: ! 426: ! 427: /* =========================================================================== ! 428: * Remove the smallest element from the heap and recreate the heap with ! 429: * one less element. Updates heap and heap_len. ! 430: */ ! 431: #define pqremove(tree, top) \ ! 432: {\ ! 433: top = heap[SMALLEST]; \ ! 434: heap[SMALLEST] = heap[heap_len--]; \ ! 435: pqdownheap(tree, SMALLEST); \ ! 436: } ! 437: ! 438: /* =========================================================================== ! 439: * Compares to subtrees, using the tree depth as tie breaker when ! 440: * the subtrees have equal frequency. This minimizes the worst case length. ! 441: */ ! 442: #define smaller(tree, n, m) \ ! 443: (tree[n].Freq < tree[m].Freq || \ ! 444: (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) ! 445: ! 446: /* =========================================================================== ! 447: * Restore the heap property by moving down the tree starting at node k, ! 448: * exchanging a node with the smallest of its two sons if necessary, stopping ! 449: * when the heap property is re-established (each father smaller than its ! 450: * two sons). ! 451: */ ! 452: local void pqdownheap(tree, k) ! 453: ct_data near *tree; /* the tree to restore */ ! 454: int k; /* node to move down */ ! 455: { ! 456: int v = heap[k]; ! 457: int j = k << 1; /* left son of k */ ! 458: while (j <= heap_len) { ! 459: /* Set j to the smallest of the two sons: */ ! 460: if (j < heap_len && smaller(tree, heap[j+1], heap[j])) j++; ! 461: ! 462: /* Exit if v is smaller than both sons */ ! 463: if (smaller(tree, v, heap[j])) break; ! 464: ! 465: /* Exchange v with the smallest son */ ! 466: heap[k] = heap[j]; k = j; ! 467: ! 468: /* And continue down the tree, setting j to the left son of k */ ! 469: j <<= 1; ! 470: } ! 471: heap[k] = v; ! 472: } ! 473: ! 474: /* =========================================================================== ! 475: * Compute the optimal bit lengths for a tree and update the total bit length ! 476: * for the current block. ! 477: * IN assertion: the fields freq and dad are set, heap[heap_max] and ! 478: * above are the tree nodes sorted by increasing frequency. ! 479: * OUT assertions: the field len is set to the optimal bit length, the ! 480: * array bl_count contains the frequencies for each bit length. ! 481: * The length opt_len is updated; static_len is also updated if stree is ! 482: * not null. ! 483: */ ! 484: local void gen_bitlen(desc) ! 485: tree_desc near *desc; /* the tree descriptor */ ! 486: { ! 487: ct_data near *tree = desc->dyn_tree; ! 488: int near *extra = desc->extra_bits; ! 489: int base = desc->extra_base; ! 490: int max_code = desc->max_code; ! 491: int max_length = desc->max_length; ! 492: ct_data near *stree = desc->static_tree; ! 493: int h; /* heap index */ ! 494: int n, m; /* iterate over the tree elements */ ! 495: int bits; /* bit length */ ! 496: int xbits; /* extra bits */ ! 497: ush f; /* frequency */ ! 498: int overflow = 0; /* number of elements with bit length too large */ ! 499: ! 500: for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; ! 501: ! 502: /* In a first pass, compute the optimal bit lengths (which may ! 503: * overflow in the case of the bit length tree). ! 504: */ ! 505: tree[heap[heap_max]].Len = 0; /* root of the heap */ ! 506: ! 507: for (h = heap_max+1; h < HEAP_SIZE; h++) { ! 508: n = heap[h]; ! 509: bits = tree[tree[n].Dad].Len + 1; ! 510: if (bits > max_length) bits = max_length, overflow++; ! 511: tree[n].Len = (ush)bits; ! 512: /* We overwrite tree[n].Dad which is no longer needed */ ! 513: ! 514: if (n > max_code) continue; /* not a leaf node */ ! 515: ! 516: bl_count[bits]++; ! 517: xbits = 0; ! 518: if (n >= base) xbits = extra[n-base]; ! 519: f = tree[n].Freq; ! 520: opt_len += (ulg)f * (bits + xbits); ! 521: if (stree) static_len += (ulg)f * (stree[n].Len + xbits); ! 522: } ! 523: if (overflow == 0) return; ! 524: ! 525: Trace((stderr,"\nbit length overflow\n")); ! 526: /* This happens for example on obj2 and pic of the Calgary corpus */ ! 527: ! 528: /* Find the first bit length which could increase: */ ! 529: do { ! 530: bits = max_length-1; ! 531: while (bl_count[bits] == 0) bits--; ! 532: bl_count[bits]--; /* move one leaf down the tree */ ! 533: bl_count[bits+1] += 2; /* move one overflow item as its brother */ ! 534: bl_count[max_length]--; ! 535: /* The brother of the overflow item also moves one step up, ! 536: * but this does not affect bl_count[max_length] ! 537: */ ! 538: overflow -= 2; ! 539: } while (overflow > 0); ! 540: ! 541: /* Now recompute all bit lengths, scanning in increasing frequency. ! 542: * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all ! 543: * lengths instead of fixing only the wrong ones. This idea is taken ! 544: * from 'ar' written by Haruhiko Okumura.) ! 545: */ ! 546: for (bits = max_length; bits != 0; bits--) { ! 547: n = bl_count[bits]; ! 548: while (n != 0) { ! 549: m = heap[--h]; ! 550: if (m > max_code) continue; ! 551: if (tree[m].Len != (unsigned) bits) { ! 552: Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); ! 553: opt_len += ((long)bits-(long)tree[m].Len)*(long)tree[m].Freq; ! 554: tree[m].Len = (ush)bits; ! 555: } ! 556: n--; ! 557: } ! 558: } ! 559: } ! 560: ! 561: /* =========================================================================== ! 562: * Generate the codes for a given tree and bit counts (which need not be ! 563: * optimal). ! 564: * IN assertion: the array bl_count contains the bit length statistics for ! 565: * the given tree and the field len is set for all tree elements. ! 566: * OUT assertion: the field code is set for all tree elements of non ! 567: * zero code length. ! 568: */ ! 569: local void gen_codes (tree, max_code) ! 570: ct_data near *tree; /* the tree to decorate */ ! 571: int max_code; /* largest code with non zero frequency */ ! 572: { ! 573: ush next_code[MAX_BITS+1]; /* next code value for each bit length */ ! 574: ush code = 0; /* running code value */ ! 575: int bits; /* bit index */ ! 576: int n; /* code index */ ! 577: ! 578: /* The distribution counts are first used to generate the code values ! 579: * without bit reversal. ! 580: */ ! 581: for (bits = 1; bits <= MAX_BITS; bits++) { ! 582: next_code[bits] = code = (code + bl_count[bits-1]) << 1; ! 583: } ! 584: /* Check that the bit counts in bl_count are consistent. The last code ! 585: * must be all ones. ! 586: */ ! 587: Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, ! 588: "inconsistent bit counts"); ! 589: Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); ! 590: ! 591: for (n = 0; n <= max_code; n++) { ! 592: int len = tree[n].Len; ! 593: if (len == 0) continue; ! 594: /* Now reverse the bits */ ! 595: tree[n].Code = bi_reverse(next_code[len]++, len); ! 596: ! 597: Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", ! 598: n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); ! 599: } ! 600: } ! 601: ! 602: /* =========================================================================== ! 603: * Construct one Huffman tree and assigns the code bit strings and lengths. ! 604: * Update the total bit length for the current block. ! 605: * IN assertion: the field freq is set for all tree elements. ! 606: * OUT assertions: the fields len and code are set to the optimal bit length ! 607: * and corresponding code. The length opt_len is updated; static_len is ! 608: * also updated if stree is not null. The field max_code is set. ! 609: */ ! 610: local void build_tree(desc) ! 611: tree_desc near *desc; /* the tree descriptor */ ! 612: { ! 613: ct_data near *tree = desc->dyn_tree; ! 614: ct_data near *stree = desc->static_tree; ! 615: int elems = desc->elems; ! 616: int n, m; /* iterate over heap elements */ ! 617: int max_code = -1; /* largest code with non zero frequency */ ! 618: int node = elems; /* next internal node of the tree */ ! 619: ! 620: /* Construct the initial heap, with least frequent element in ! 621: * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. ! 622: * heap[0] is not used. ! 623: */ ! 624: heap_len = 0, heap_max = HEAP_SIZE; ! 625: ! 626: for (n = 0; n < elems; n++) { ! 627: if (tree[n].Freq != 0) { ! 628: heap[++heap_len] = max_code = n; ! 629: depth[n] = 0; ! 630: } else { ! 631: tree[n].Len = 0; ! 632: } ! 633: } ! 634: ! 635: /* The pkzip format requires that at least one distance code exists, ! 636: * and that at least one bit should be sent even if there is only one ! 637: * possible code. So to avoid special checks later on we force at least ! 638: * two codes of non zero frequency. ! 639: */ ! 640: while (heap_len < 2) { ! 641: int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0); ! 642: tree[new].Freq = 1; ! 643: depth[new] = 0; ! 644: opt_len--; if (stree) static_len -= stree[new].Len; ! 645: /* new is 0 or 1 so it does not have extra bits */ ! 646: } ! 647: desc->max_code = max_code; ! 648: ! 649: /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, ! 650: * establish sub-heaps of increasing lengths: ! 651: */ ! 652: for (n = heap_len/2; n >= 1; n--) pqdownheap(tree, n); ! 653: ! 654: /* Construct the Huffman tree by repeatedly combining the least two ! 655: * frequent nodes. ! 656: */ ! 657: do { ! 658: pqremove(tree, n); /* n = node of least frequency */ ! 659: m = heap[SMALLEST]; /* m = node of next least frequency */ ! 660: ! 661: heap[--heap_max] = n; /* keep the nodes sorted by frequency */ ! 662: heap[--heap_max] = m; ! 663: ! 664: /* Create a new node father of n and m */ ! 665: tree[node].Freq = tree[n].Freq + tree[m].Freq; ! 666: depth[node] = (uch) (MAX(depth[n], depth[m]) + 1); ! 667: tree[n].Dad = tree[m].Dad = (ush)node; ! 668: #ifdef DUMP_BL_TREE ! 669: if (tree == bl_tree) { ! 670: fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", ! 671: node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); ! 672: } ! 673: #endif ! 674: /* and insert the new node in the heap */ ! 675: heap[SMALLEST] = node++; ! 676: pqdownheap(tree, SMALLEST); ! 677: ! 678: } while (heap_len >= 2); ! 679: ! 680: heap[--heap_max] = heap[SMALLEST]; ! 681: ! 682: /* At this point, the fields freq and dad are set. We can now ! 683: * generate the bit lengths. ! 684: */ ! 685: gen_bitlen((tree_desc near *)desc); ! 686: ! 687: /* The field len is now set, we can generate the bit codes */ ! 688: gen_codes ((ct_data near *)tree, max_code); ! 689: } ! 690: ! 691: /* =========================================================================== ! 692: * Scan a literal or distance tree to determine the frequencies of the codes ! 693: * in the bit length tree. Updates opt_len to take into account the repeat ! 694: * counts. (The contribution of the bit length codes will be added later ! 695: * during the construction of bl_tree.) ! 696: */ ! 697: local void scan_tree (tree, max_code) ! 698: ct_data near *tree; /* the tree to be scanned */ ! 699: int max_code; /* and its largest code of non zero frequency */ ! 700: { ! 701: int n; /* iterates over all tree elements */ ! 702: int prevlen = -1; /* last emitted length */ ! 703: int curlen; /* length of current code */ ! 704: int nextlen = tree[0].Len; /* length of next code */ ! 705: int count = 0; /* repeat count of the current code */ ! 706: int max_count = 7; /* max repeat count */ ! 707: int min_count = 4; /* min repeat count */ ! 708: ! 709: if (nextlen == 0) max_count = 138, min_count = 3; ! 710: tree[max_code+1].Len = (ush)-1; /* guard */ ! 711: ! 712: for (n = 0; n <= max_code; n++) { ! 713: curlen = nextlen; nextlen = tree[n+1].Len; ! 714: if (++count < max_count && curlen == nextlen) { ! 715: continue; ! 716: } else if (count < min_count) { ! 717: bl_tree[curlen].Freq += count; ! 718: } else if (curlen != 0) { ! 719: if (curlen != prevlen) bl_tree[curlen].Freq++; ! 720: bl_tree[REP_3_6].Freq++; ! 721: } else if (count <= 10) { ! 722: bl_tree[REPZ_3_10].Freq++; ! 723: } else { ! 724: bl_tree[REPZ_11_138].Freq++; ! 725: } ! 726: count = 0; prevlen = curlen; ! 727: if (nextlen == 0) { ! 728: max_count = 138, min_count = 3; ! 729: } else if (curlen == nextlen) { ! 730: max_count = 6, min_count = 3; ! 731: } else { ! 732: max_count = 7, min_count = 4; ! 733: } ! 734: } ! 735: } ! 736: ! 737: /* =========================================================================== ! 738: * Send a literal or distance tree in compressed form, using the codes in ! 739: * bl_tree. ! 740: */ ! 741: local void send_tree (tree, max_code) ! 742: ct_data near *tree; /* the tree to be scanned */ ! 743: int max_code; /* and its largest code of non zero frequency */ ! 744: { ! 745: int n; /* iterates over all tree elements */ ! 746: int prevlen = -1; /* last emitted length */ ! 747: int curlen; /* length of current code */ ! 748: int nextlen = tree[0].Len; /* length of next code */ ! 749: int count = 0; /* repeat count of the current code */ ! 750: int max_count = 7; /* max repeat count */ ! 751: int min_count = 4; /* min repeat count */ ! 752: ! 753: /* tree[max_code+1].Len = -1; */ /* guard already set */ ! 754: if (nextlen == 0) max_count = 138, min_count = 3; ! 755: ! 756: for (n = 0; n <= max_code; n++) { ! 757: curlen = nextlen; nextlen = tree[n+1].Len; ! 758: if (++count < max_count && curlen == nextlen) { ! 759: continue; ! 760: } else if (count < min_count) { ! 761: do { send_code(curlen, bl_tree); } while (--count != 0); ! 762: ! 763: } else if (curlen != 0) { ! 764: if (curlen != prevlen) { ! 765: send_code(curlen, bl_tree); count--; ! 766: } ! 767: Assert(count >= 3 && count <= 6, " 3_6?"); ! 768: send_code(REP_3_6, bl_tree); send_bits(count-3, 2); ! 769: ! 770: } else if (count <= 10) { ! 771: send_code(REPZ_3_10, bl_tree); send_bits(count-3, 3); ! 772: ! 773: } else { ! 774: send_code(REPZ_11_138, bl_tree); send_bits(count-11, 7); ! 775: } ! 776: count = 0; prevlen = curlen; ! 777: if (nextlen == 0) { ! 778: max_count = 138, min_count = 3; ! 779: } else if (curlen == nextlen) { ! 780: max_count = 6, min_count = 3; ! 781: } else { ! 782: max_count = 7, min_count = 4; ! 783: } ! 784: } ! 785: } ! 786: ! 787: /* =========================================================================== ! 788: * Construct the Huffman tree for the bit lengths and return the index in ! 789: * bl_order of the last bit length code to send. ! 790: */ ! 791: local int build_bl_tree() ! 792: { ! 793: int max_blindex; /* index of last bit length code of non zero freq */ ! 794: ! 795: /* Determine the bit length frequencies for literal and distance trees */ ! 796: scan_tree((ct_data near *)dyn_ltree, l_desc.max_code); ! 797: scan_tree((ct_data near *)dyn_dtree, d_desc.max_code); ! 798: ! 799: /* Build the bit length tree: */ ! 800: build_tree((tree_desc near *)(&bl_desc)); ! 801: /* opt_len now includes the length of the tree representations, except ! 802: * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. ! 803: */ ! 804: ! 805: /* Determine the number of bit length codes to send. The pkzip format ! 806: * requires that at least 4 bit length codes be sent. (appnote.txt says ! 807: * 3 but the actual value used is 4.) ! 808: */ ! 809: for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { ! 810: if (bl_tree[bl_order[max_blindex]].Len != 0) break; ! 811: } ! 812: /* Update opt_len to include the bit length tree and counts */ ! 813: opt_len += 3*(max_blindex+1) + 5+5+4; ! 814: Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len)); ! 815: ! 816: return max_blindex; ! 817: } ! 818: ! 819: /* =========================================================================== ! 820: * Send the header for a block using dynamic Huffman trees: the counts, the ! 821: * lengths of the bit length codes, the literal tree and the distance tree. ! 822: * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. ! 823: */ ! 824: local void send_all_trees(lcodes, dcodes, blcodes) ! 825: int lcodes, dcodes, blcodes; /* number of codes for each tree */ ! 826: { ! 827: int rank; /* index in bl_order */ ! 828: ! 829: Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); ! 830: Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, ! 831: "too many codes"); ! 832: Tracev((stderr, "\nbl counts: ")); ! 833: send_bits(lcodes-257, 5); /* not +255 as stated in appnote.txt */ ! 834: send_bits(dcodes-1, 5); ! 835: send_bits(blcodes-4, 4); /* not -3 as stated in appnote.txt */ ! 836: for (rank = 0; rank < blcodes; rank++) { ! 837: Tracev((stderr, "\nbl code %2d ", bl_order[rank])); ! 838: send_bits(bl_tree[bl_order[rank]].Len, 3); ! 839: } ! 840: Tracev((stderr, "\nbl tree: sent %ld", bits_sent)); ! 841: ! 842: send_tree((ct_data near *)dyn_ltree, lcodes-1); /* send the literal tree */ ! 843: Tracev((stderr, "\nlit tree: sent %ld", bits_sent)); ! 844: ! 845: send_tree((ct_data near *)dyn_dtree, dcodes-1); /* send the distance tree */ ! 846: Tracev((stderr, "\ndist tree: sent %ld", bits_sent)); ! 847: } ! 848: ! 849: /* =========================================================================== ! 850: * Determine the best encoding for the current block: dynamic trees, static ! 851: * trees or store, and output the encoded block to the zip file. This function ! 852: * returns the total compressed length for the file so far. ! 853: */ ! 854: ulg flush_block(buf, stored_len, eof) ! 855: char *buf; /* input block, or NULL if too old */ ! 856: ulg stored_len; /* length of input block */ ! 857: int eof; /* true if this is the last block for a file */ ! 858: { ! 859: ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ ! 860: int max_blindex; /* index of last bit length code of non zero freq */ ! 861: ! 862: flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */ ! 863: ! 864: /* Check if the file is ascii or binary */ ! 865: if (*file_type == (ush)UNKNOWN) set_file_type(); ! 866: ! 867: /* Construct the literal and distance trees */ ! 868: build_tree((tree_desc near *)(&l_desc)); ! 869: Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len)); ! 870: ! 871: build_tree((tree_desc near *)(&d_desc)); ! 872: Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len)); ! 873: /* At this point, opt_len and static_len are the total bit lengths of ! 874: * the compressed block data, excluding the tree representations. ! 875: */ ! 876: ! 877: /* Build the bit length tree for the above two trees, and get the index ! 878: * in bl_order of the last bit length code to send. ! 879: */ ! 880: max_blindex = build_bl_tree(); ! 881: ! 882: /* Determine the best encoding. Compute first the block length in bytes */ ! 883: opt_lenb = (opt_len+3+7)>>3; ! 884: static_lenb = (static_len+3+7)>>3; ! 885: input_len += stored_len; /* for debugging only */ ! 886: ! 887: Trace((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ", ! 888: opt_lenb, opt_len, static_lenb, static_len, stored_len, ! 889: last_lit, last_dist)); ! 890: ! 891: if (static_lenb <= opt_lenb) opt_lenb = static_lenb; ! 892: ! 893: /* If compression failed and this is the first and last block, ! 894: * and if the zip file can be seeked (to rewrite the local header), ! 895: * the whole file is transformed into a stored file: ! 896: */ ! 897: #ifdef FORCE_METHOD ! 898: if (level == 1 && eof && compressed_len == 0L) { /* force stored file */ ! 899: #else ! 900: if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) { ! 901: #endif ! 902: /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ ! 903: if (buf == (char*)0) error ("block vanished"); ! 904: ! 905: copy_block(buf, (unsigned)stored_len, 0); /* without header */ ! 906: compressed_len = stored_len << 3; ! 907: *file_method = STORED; ! 908: ! 909: #ifdef FORCE_METHOD ! 910: } else if (level == 2 && buf != (char*)0) { /* force stored block */ ! 911: #else ! 912: } else if (stored_len+4 <= opt_lenb && buf != (char*)0) { ! 913: /* 4: two words for the lengths */ ! 914: #endif ! 915: /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. ! 916: * Otherwise we can't have processed more than WSIZE input bytes since ! 917: * the last block flush, because compression would have been ! 918: * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to ! 919: * transform a block into a stored block. ! 920: */ ! 921: send_bits((STORED_BLOCK<<1)+eof, 3); /* send block type */ ! 922: compressed_len = (compressed_len + 3 + 7) & ~7L; ! 923: compressed_len += (stored_len + 4) << 3; ! 924: ! 925: copy_block(buf, (unsigned)stored_len, 1); /* with header */ ! 926: ! 927: #ifdef FORCE_METHOD ! 928: } else if (level == 3) { /* force static trees */ ! 929: #else ! 930: } else if (static_lenb == opt_lenb) { ! 931: #endif ! 932: send_bits((STATIC_TREES<<1)+eof, 3); ! 933: compress_block((ct_data near *)static_ltree, (ct_data near *)static_dtree); ! 934: compressed_len += 3 + static_len; ! 935: } else { ! 936: send_bits((DYN_TREES<<1)+eof, 3); ! 937: send_all_trees(l_desc.max_code+1, d_desc.max_code+1, max_blindex+1); ! 938: compress_block((ct_data near *)dyn_ltree, (ct_data near *)dyn_dtree); ! 939: compressed_len += 3 + opt_len; ! 940: } ! 941: Assert (compressed_len == bits_sent, "bad compressed size"); ! 942: init_block(); ! 943: ! 944: if (eof) { ! 945: Assert (input_len == isize, "bad input size"); ! 946: bi_windup(); ! 947: compressed_len += 7; /* align on byte boundary */ ! 948: } ! 949: Tracev((stderr,"\ncomprlen %lu(%lu) ", compressed_len>>3, ! 950: compressed_len-7*eof)); ! 951: ! 952: return compressed_len >> 3; ! 953: } ! 954: ! 955: /* =========================================================================== ! 956: * Save the match info and tally the frequency counts. Return true if ! 957: * the current block must be flushed. ! 958: */ ! 959: int ct_tally (dist, lc) ! 960: int dist; /* distance of matched string */ ! 961: int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ ! 962: { ! 963: l_buf[last_lit++] = (uch)lc; ! 964: if (dist == 0) { ! 965: /* lc is the unmatched char */ ! 966: dyn_ltree[lc].Freq++; ! 967: } else { ! 968: /* Here, lc is the match length - MIN_MATCH */ ! 969: dist--; /* dist = match distance - 1 */ ! 970: Assert((ush)dist < (ush)MAX_DIST && ! 971: (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && ! 972: (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match"); ! 973: ! 974: dyn_ltree[length_code[lc]+LITERALS+1].Freq++; ! 975: dyn_dtree[d_code(dist)].Freq++; ! 976: ! 977: d_buf[last_dist++] = (ush)dist; ! 978: flags |= flag_bit; ! 979: } ! 980: flag_bit <<= 1; ! 981: ! 982: /* Output the flags if they fill a byte: */ ! 983: if ((last_lit & 7) == 0) { ! 984: flag_buf[last_flags++] = flags; ! 985: flags = 0, flag_bit = 1; ! 986: } ! 987: /* Try to guess if it is profitable to stop the current block here */ ! 988: if (level > 2 && (last_lit & 0xfff) == 0) { ! 989: /* Compute an upper bound for the compressed length */ ! 990: ulg out_length = (ulg)last_lit*8L; ! 991: ulg in_length = (ulg)strstart-block_start; ! 992: int dcode; ! 993: for (dcode = 0; dcode < D_CODES; dcode++) { ! 994: out_length += (ulg)dyn_dtree[dcode].Freq*(5L+extra_dbits[dcode]); ! 995: } ! 996: out_length >>= 3; ! 997: Trace((stderr,"\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ", ! 998: last_lit, last_dist, in_length, out_length, ! 999: 100L - out_length*100L/in_length)); ! 1000: if (last_dist < last_lit/2 && out_length < in_length/2) return 1; ! 1001: } ! 1002: return (last_lit == LIT_BUFSIZE-1 || last_dist == DIST_BUFSIZE); ! 1003: /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K ! 1004: * on 16 bit machines and because stored blocks are restricted to ! 1005: * 64K-1 bytes. ! 1006: */ ! 1007: } ! 1008: ! 1009: /* =========================================================================== ! 1010: * Send the block data compressed using the given Huffman trees ! 1011: */ ! 1012: local void compress_block(ltree, dtree) ! 1013: ct_data near *ltree; /* literal tree */ ! 1014: ct_data near *dtree; /* distance tree */ ! 1015: { ! 1016: unsigned dist; /* distance of matched string */ ! 1017: int lc; /* match length or unmatched char (if dist == 0) */ ! 1018: unsigned lx = 0; /* running index in l_buf */ ! 1019: unsigned dx = 0; /* running index in d_buf */ ! 1020: unsigned fx = 0; /* running index in flag_buf */ ! 1021: uch flag = 0; /* current flags */ ! 1022: unsigned code; /* the code to send */ ! 1023: int extra; /* number of extra bits to send */ ! 1024: ! 1025: if (last_lit != 0) do { ! 1026: if ((lx & 7) == 0) flag = flag_buf[fx++]; ! 1027: lc = l_buf[lx++]; ! 1028: if ((flag & 1) == 0) { ! 1029: send_code(lc, ltree); /* send a literal byte */ ! 1030: Tracecv(isgraph(lc), (stderr," '%c' ", lc)); ! 1031: } else { ! 1032: /* Here, lc is the match length - MIN_MATCH */ ! 1033: code = length_code[lc]; ! 1034: send_code(code+LITERALS+1, ltree); /* send the length code */ ! 1035: extra = extra_lbits[code]; ! 1036: if (extra != 0) { ! 1037: lc -= base_length[code]; ! 1038: send_bits(lc, extra); /* send the extra length bits */ ! 1039: } ! 1040: dist = d_buf[dx++]; ! 1041: /* Here, dist is the match distance - 1 */ ! 1042: code = d_code(dist); ! 1043: Assert (code < D_CODES, "bad d_code"); ! 1044: ! 1045: send_code(code, dtree); /* send the distance code */ ! 1046: extra = extra_dbits[code]; ! 1047: if (extra != 0) { ! 1048: dist -= base_dist[code]; ! 1049: send_bits(dist, extra); /* send the extra distance bits */ ! 1050: } ! 1051: } /* literal or match pair ? */ ! 1052: flag >>= 1; ! 1053: } while (lx < last_lit); ! 1054: ! 1055: send_code(END_BLOCK, ltree); ! 1056: } ! 1057: ! 1058: /* =========================================================================== ! 1059: * Set the file type to ASCII or BINARY, using a crude approximation: ! 1060: * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. ! 1061: * IN assertion: the fields freq of dyn_ltree are set and the total of all ! 1062: * frequencies does not exceed 64K (to fit in an int on 16 bit machines). ! 1063: */ ! 1064: local void set_file_type() ! 1065: { ! 1066: int n = 0; ! 1067: unsigned ascii_freq = 0; ! 1068: unsigned bin_freq = 0; ! 1069: while (n < 7) bin_freq += dyn_ltree[n++].Freq; ! 1070: while (n < 128) ascii_freq += dyn_ltree[n++].Freq; ! 1071: while (n < LITERALS) bin_freq += dyn_ltree[n++].Freq; ! 1072: *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII; ! 1073: if (*file_type == BINARY && translate_eol) { ! 1074: warn("-l used on binary file", ""); ! 1075: } ! 1076: }
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