1 /* Portions Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

     2  * All rights reserved.

     3  */

     4 

     5 /* trees.cpp -- output deflated data using Huffman coding

     6  * Copyright (C) 1995-2005 Jean-loup Gailly

     7  * For conditions of distribution and use, see copyright notice in zlib.h

     8  */

     9 

    10 /*

    11  *  ALGORITHM

    12  *

    13  *      The "deflation" process uses several Huffman trees. The more

    14  *      common source values are represented by shorter bit sequences.

    15  *

    16  *      Each code tree is stored in a compressed form which is itself

    17  * a Huffman encoding of the lengths of all the code strings (in

    18  * ascending order by source values).  The actual code strings are

    19  * reconstructed from the lengths in the inflate process, as described

    20  * in the deflate specification.

    21  *

    22  *  REFERENCES

    23  *

    24  *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".

    25  *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc

    26  *

    27  *      Storer, James A.

    28  *          Data Compression:  Methods and Theory, pp. 49-50.

    29  *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.

    30  *

    31  *      Sedgewick, R.

    32  *          Algorithms, p290.

    33  *          Addison-Wesley, 1983. ISBN 0-201-06672-6.

    34  */

    35 

    36 /* @(#) $Id$ */

    37 

    38 /* #define GEN_TREES_H */

    39 

    40 #include "deflate.h"

    41 

    42 #ifdef DEBUG

    43 #  include <ctype.h>

    44 #endif

    45 

    46 /* ===========================================================================

    47  * Constants

    48  */

    49 

    50 #define MAX_BL_BITS 7

    51 /* Bit length codes must not exceed MAX_BL_BITS bits */

    52 

    53 #define END_BLOCK 256

    54 /* end of block literal code */

    55 

    56 #define REP_3_6      16

    57 /* repeat previous bit length 3-6 times (2 bits of repeat count) */

    58 

    59 #define REPZ_3_10    17

    60 /* repeat a zero length 3-10 times  (3 bits of repeat count) */

    61 

    62 #define REPZ_11_138  18

    63 /* repeat a zero length 11-138 times  (7 bits of repeat count) */

    64 

    65 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */

    66    = {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};

    67 

    68 local const int extra_dbits[D_CODES] /* extra bits for each distance code */

    69    = {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};

    70 

    71 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */

    72    = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};

    73 

    74 local const uch bl_order[BL_CODES]

    75    = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};

    76 /* The lengths of the bit length codes are sent in order of decreasing

    77  * probability, to avoid transmitting the lengths for unused bit length codes.

    78  */

    79 

    80 #define Buf_size (8 * 2*sizeof(char))

    81 /* Number of bits used within bi_buf. (bi_buf might be implemented on

    82  * more than 16 bits on some systems.)

    83  */

    84 

    85 /* ===========================================================================

    86  * Local data. These are initialized only once.

    87  */

    88 

    89 #define DIST_CODE_LEN  512 /* see definition of array dist_code below */

    90 

    91 #if defined(GEN_TREES_H) || !defined(STDC)

    92 /* non ANSI compilers may not accept trees.h */

    93 

    94 local ct_data static_ltree[L_CODES+2];

    95 /* The static literal tree. Since the bit lengths are imposed, there is no

    96  * need for the L_CODES extra codes used during heap construction. However

    97  * The codes 286 and 287 are needed to build a canonical tree (see _tr_init

    98  * below).

    99  */

   100 

   101 local ct_data static_dtree[D_CODES];

   102 /* The static distance tree. (Actually a trivial tree since all codes use

   103  * 5 bits.)

   104  */

   105 

   106 uch _dist_code[DIST_CODE_LEN];

   107 /* Distance codes. The first 256 values correspond to the distances

   108  * 3 .. 258, the last 256 values correspond to the top 8 bits of

   109  * the 15 bit distances.

   110  */

   111 

   112 uch _length_code[MAX_MATCH-MIN_MATCH+1];

   113 /* length code for each normalized match length (0 == MIN_MATCH) */

   114 

   115 local int base_length[LENGTH_CODES];

   116 /* First normalized length for each code (0 = MIN_MATCH) */

   117 

   118 local int base_dist[D_CODES];

   119 /* First normalized distance for each code (0 = distance of 1) */

   120 

   121 #else

   122 #  include "trees.h"

   123 #endif /* GEN_TREES_H */

   124 

   125 struct static_tree_desc_s {

   126     const ct_data *static_tree;  /* static tree or NULL */

   127     const intf *extra_bits;      /* extra bits for each code or NULL */

   128     int     extra_base;          /* base index for extra_bits */

   129     int     elems;               /* max number of elements in the tree */

   130     int     max_length;          /* max bit length for the codes */

   131 };

   132 #ifndef SYMBIAN_EZLIB_DEVICE

   133 local static_tree_desc  static_l_desc =

   134 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};

   135 

   136 local static_tree_desc  static_d_desc =

   137 {static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};

   138 

   139 local static_tree_desc  static_bl_desc =

   140 {(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};

   141 

   142 #else

   143 

   144 local const static_tree_desc  static_l_desc =

   145 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};

   146 

   147 local const static_tree_desc  static_d_desc =

   148 {static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};

   149 

   150 local const static_tree_desc  static_bl_desc =

   151 {(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};

   152 

   153 #endif //SYMBIAN_EZLIB_DEVICE

   154 

   155 

   156 /* ===========================================================================

   157  * Local (static) routines in this file.

   158  */

   159 

   160 local void tr_static_init OF((void));

   161 local void init_block     OF((deflate_state *s));

   162 local void pqdownheap     OF((deflate_state *s, ct_data *tree, int k));

   163 local void gen_bitlen     OF((deflate_state *s, tree_desc *desc));

   164 local void gen_codes      OF((ct_data *tree, int max_code, ushf *bl_count));

   165 local void build_tree     OF((deflate_state *s, tree_desc *desc));

   166 local void scan_tree      OF((deflate_state *s, ct_data *tree, int max_code));

   167 local void send_tree      OF((deflate_state *s, ct_data *tree, int max_code));

   168 local int  build_bl_tree  OF((deflate_state *s));

   169 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,

   170                               int blcodes));

   171 local void compress_block OF((deflate_state *s, ct_data *ltree,

   172                               ct_data *dtree));

   173 local void set_data_type  OF((deflate_state *s));

   174 local unsigned bi_reverse OF((unsigned value, int length));

   175 local void bi_windup      OF((deflate_state *s));

   176 local void bi_flush       OF((deflate_state *s));

   177 local void copy_block     OF((deflate_state *s, charf *buf, unsigned len,

   178                               int header));

   179 

   180 #ifdef GEN_TREES_H

   181 local void gen_trees_header OF((void));

   182 #endif

   183 

   184 #ifndef DEBUG

   185 #  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)

   186    /* Send a code of the given tree. c and tree must not have side effects */

   187 

   188 #else /* DEBUG */

   189 #  define send_code(s, c, tree) \

   190      { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \

   191        send_bits(s, tree[c].Code, tree[c].Len); }

   192 #endif

   193 

   194 /* ===========================================================================

   195  * Output a short LSB first on the stream.

   196  * IN assertion: there is enough room in pendingBuf.

   197  */

   198 #define put_short(s, w) { \

   199     put_byte(s, (uch)((w) & 0xff)); \

   200     put_byte(s, (uch)((ush)(w) >> 8)); \

   201 }

   202 

   203 /* ===========================================================================

   204  * Send a value on a given number of bits.

   205  * IN assertion: length <= 16 and value fits in length bits.

   206  */

   207 #ifdef DEBUG

   208 local void send_bits      OF((deflate_state *s, int value, int length));

   209 

   210 #ifdef __SYMBIAN32__

   211 local void send_bits(deflate_state * s, int value,int  length)

   212 #else	

   213 local void send_bits(s, value, length)

   214     deflate_state *s;

   215     int value;  /* value to send */

   216     int length; /* number of bits */

   217 #endif //__SYMBIAN32__

   218 {

   219     Tracevv((stderr," l %2d v %4x ", length, value));

   220     Assert(length > 0 && length <= 15, "invalid length");

   221     s->bits_sent += (ulg)length;

   222 

   223     /* If not enough room in bi_buf, use (valid) bits from bi_buf and

   224      * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))

   225      * unused bits in value.

   226      */

   227     if (s->bi_valid > (int)Buf_size - length) {

   228         s->bi_buf |= (value << s->bi_valid);

   229         put_short(s, s->bi_buf);

   230         s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);

   231         s->bi_valid += length - Buf_size;

   232     } else {

   233         s->bi_buf |= value << s->bi_valid;

   234         s->bi_valid += length;

   235     }

   236 }

   237 #else /* !DEBUG */

   238 

   239 #define send_bits(s, value, length) \

   240 { int len = length;\

   241   if (s->bi_valid > (int)Buf_size - len) {\

   242     int val = value;\

   243     s->bi_buf |= (val << s->bi_valid);\

   244     put_short(s, s->bi_buf);\

   245 	s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\

   246     s->bi_valid += len - Buf_size;\

   247   } else {\

   248     s->bi_buf |= (value) << s->bi_valid;\

   249     s->bi_valid += len;\

   250   }\

   251 }

   252 #endif /* DEBUG */

   253 

   254 

   255 /* the arguments must not have side effects */

   256 

   257 /* ===========================================================================

   258  * Initialize the various 'constant' tables.

   259  */

   260 local void tr_static_init()

   261 {

   262 #if defined(GEN_TREES_H) || !defined(STDC)

   263     static int static_init_done = 0;

   264     int n;        /* iterates over tree elements */

   265     int bits;     /* bit counter */

   266     int length;   /* length value */

   267     int code;     /* code value */

   268     int dist;     /* distance index */

   269     ush bl_count[MAX_BITS+1];

   270     /* number of codes at each bit length for an optimal tree */

   271 

   272     if (static_init_done) return;

   273 

   274     /* For some embedded targets, global variables are not initialized: */

   275     static_l_desc.static_tree = static_ltree;

   276     static_l_desc.extra_bits = extra_lbits;

   277     static_d_desc.static_tree = static_dtree;

   278     static_d_desc.extra_bits = extra_dbits;

   279     static_bl_desc.extra_bits = extra_blbits;

   280 

   281     /* Initialize the mapping length (0..255) -> length code (0..28) */

   282     length = 0;

   283     for (code = 0; code < LENGTH_CODES-1; code++) {

   284         base_length[code] = length;

   285         for (n = 0; n < (1<<extra_lbits[code]); n++) {

   286             _length_code[length++] = (uch)code;

   287         }

   288     }

   289     Assert (length == 256, "tr_static_init: length != 256");

   290     /* Note that the length 255 (match length 258) can be represented

   291      * in two different ways: code 284 + 5 bits or code 285, so we

   292      * overwrite length_code[255] to use the best encoding:

   293      */

   294     _length_code[length-1] = (uch)code;

   295 

   296     /* Initialize the mapping dist (0..32K) -> dist code (0..29) */

   297     dist = 0;

   298     for (code = 0 ; code < 16; code++) {

   299         base_dist[code] = dist;

   300         for (n = 0; n < (1<<extra_dbits[code]); n++) {

   301             _dist_code[dist++] = (uch)code;

   302         }

   303     }

   304     Assert (dist == 256, "tr_static_init: dist != 256");

   305     dist >>= 7; /* from now on, all distances are divided by 128 */

   306     for ( ; code < D_CODES; code++) {

   307         base_dist[code] = dist << 7;

   308         for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {

   309             _dist_code[256 + dist++] = (uch)code;

   310         }

   311     }

   312     Assert (dist == 256, "tr_static_init: 256+dist != 512");

   313 

   314     /* Construct the codes of the static literal tree */

   315     for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;

   316     n = 0;

   317     while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;

   318     while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;

   319     while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;

   320     while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;

   321     /* Codes 286 and 287 do not exist, but we must include them in the

   322      * tree construction to get a canonical Huffman tree (longest code

   323      * all ones)

   324      */

   325     gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);

   326 

   327     /* The static distance tree is trivial: */

   328     for (n = 0; n < D_CODES; n++) {

   329         static_dtree[n].Len = 5;

   330         static_dtree[n].Code = bi_reverse((unsigned)n, 5);

   331     }

   332     static_init_done = 1;

   333 

   334 #  ifdef GEN_TREES_H

   335     gen_trees_header();

   336 #  endif

   337 #endif /* defined(GEN_TREES_H) || !defined(STDC) */

   338 }

   339 /* ===========================================================================

   340  * Genererate the file trees.h describing the static trees.

   341  */

   342 #ifdef GEN_TREES_H

   343 #  ifndef DEBUG

   344 #    include <stdio.h>

   345 #  endif

   346 

   347 #  define SEPARATOR(i, last, width) \

   348       ((i) == (last)? "\n};\n\n" :    \

   349        ((i) % (width) == (width)-1 ? ",\n" : ", "))

   350 

   351 void gen_trees_header()

   352 {

   353     FILE *header = fopen("trees.h", "w");

   354     int i;

   355 

   356     Assert (header != NULL, "Can't open trees.h");

   357     fprintf(header,

   358             "/* header created automatically with -DGEN_TREES_H */\n\n");

   359 

   360     fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");

   361     for (i = 0; i < L_CODES+2; i++) {

   362         fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,

   363                 static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));

   364     }

   365 

   366     fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");

   367     for (i = 0; i < D_CODES; i++) {

   368         fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,

   369                 static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));

   370     }

   371 

   372     fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");

   373     for (i = 0; i < DIST_CODE_LEN; i++) {

   374         fprintf(header, "%2u%s", _dist_code[i],

   375                 SEPARATOR(i, DIST_CODE_LEN-1, 20));

   376     }

   377 

   378     fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");

   379     for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {

   380         fprintf(header, "%2u%s", _length_code[i],

   381                 SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));

   382     }

   383 

   384     fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");

   385     for (i = 0; i < LENGTH_CODES; i++) {

   386         fprintf(header, "%1u%s", base_length[i],

   387                 SEPARATOR(i, LENGTH_CODES-1, 20));

   388     }

   389 

   390     fprintf(header, "local const int base_dist[D_CODES] = {\n");

   391     for (i = 0; i < D_CODES; i++) {

   392         fprintf(header, "%5u%s", base_dist[i],

   393                 SEPARATOR(i, D_CODES-1, 10));

   394     }

   395 

   396     fclose(header);

   397 }

   398 #endif /* GEN_TREES_H */

   399 

   400 /* ===========================================================================

   401  * Initialize the tree data structures for a new zlib stream.

   402  */

   403 #ifdef __SYMBIAN32__

   404 void _tr_init(   deflate_state * s)

   405 #else    

   406 void _tr_init(s)

   407     deflate_state *s;

   408 #endif //__SYMBIAN32__

   409 {

   410     tr_static_init();

   411 

   412     s->l_desc.dyn_tree = s->dyn_ltree;

   413     s->l_desc.stat_desc = &static_l_desc;

   414 

   415     s->d_desc.dyn_tree = s->dyn_dtree;

   416     s->d_desc.stat_desc = &static_d_desc;

   417 

   418     s->bl_desc.dyn_tree = s->bl_tree;

   419     s->bl_desc.stat_desc = &static_bl_desc;

   420 

   421     s->bi_buf = 0;

   422     s->bi_valid = 0;

   423     s->last_eob_len = 8; /* enough lookahead for inflate */

   424 #ifdef DEBUG

   425     s->compressed_len = 0L;

   426     s->bits_sent = 0L;

   427 #endif

   428 

   429     /* Initialize the first block of the first file: */

   430     init_block(s);

   431 }

   432 

   433 /* ===========================================================================

   434  * Initialize a new block.

   435  */

   436 #ifdef __SYMBIAN32__

   437 local void init_block(    deflate_state * s)

   438 #else

   439 local void init_block(s)

   440     deflate_state *s;

   441 #endif //__SYMBIAN32__

   442 {

   443     int n; /* iterates over tree elements */

   444 

   445     /* Initialize the trees. */

   446     for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;

   447     for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;

   448     for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;

   449 

   450     s->dyn_ltree[END_BLOCK].Freq = 1;

   451     s->opt_len = s->static_len = 0L;

   452     s->last_lit = s->matches = 0;

   453 }

   454 

   455 #define SMALLEST 1

   456 /* Index within the heap array of least frequent node in the Huffman tree */

   457 

   458 

   459 /* ===========================================================================

   460  * Remove the smallest element from the heap and recreate the heap with

   461  * one less element. Updates heap and heap_len.

   462  */

   463 #define pqremove(s, tree, top) \

   464 {\

   465     top = s->heap[SMALLEST]; \

   466     s->heap[SMALLEST] = s->heap[s->heap_len--]; \

   467     pqdownheap(s, tree, SMALLEST); \

   468 }

   469 

   470 /* ===========================================================================

   471  * Compares to subtrees, using the tree depth as tie breaker when

   472  * the subtrees have equal frequency. This minimizes the worst case length.

   473  */

   474 #define smaller(tree, n, m, depth) \

   475    (tree[n].Freq < tree[m].Freq || \

   476    (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))

   477 

   478 /* ===========================================================================

   479  * Restore the heap property by moving down the tree starting at node k,

   480  * exchanging a node with the smallest of its two sons if necessary, stopping

   481  * when the heap property is re-established (each father smaller than its

   482  * two sons).

   483  */

   484 #ifdef __SYMBIAN32__

   485 local void pqdownheap(  deflate_state * s,ct_data *  tree,int k)

   486 #else

   487 local void pqdownheap(s, tree, k)

   488     deflate_state *s;

   489     ct_data *tree;  /* the tree to restore */

   490     int k;               /* node to move down */

   491 #endif //__SYMBIAN32__	

   492 {

   493     int v = s->heap[k];

   494     int j = k << 1;  /* left son of k */

   495     while (j <= s->heap_len) {

   496         /* Set j to the smallest of the two sons: */

   497         if (j < s->heap_len &&

   498             smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {

   499             j++;

   500         }

   501         /* Exit if v is smaller than both sons */

   502         if (smaller(tree, v, s->heap[j], s->depth)) break;

   503 

   504         /* Exchange v with the smallest son */

   505         s->heap[k] = s->heap[j];  k = j;

   506 

   507         /* And continue down the tree, setting j to the left son of k */

   508         j <<= 1;

   509     }

   510     s->heap[k] = v;

   511 }

   512 

   513 /* ===========================================================================

   514  * Compute the optimal bit lengths for a tree and update the total bit length

   515  * for the current block.

   516  * IN assertion: the fields freq and dad are set, heap[heap_max] and

   517  *    above are the tree nodes sorted by increasing frequency.

   518  * OUT assertions: the field len is set to the optimal bit length, the

   519  *     array bl_count contains the frequencies for each bit length.

   520  *     The length opt_len is updated; static_len is also updated if stree is

   521  *     not null.

   522  */

   523 #ifdef __SYMBIAN32__

   524 local void gen_bitlen(    deflate_state * s,     tree_desc * desc)

   525 #else

   526 local void gen_bitlen(s, desc)

   527     deflate_state *s;

   528     tree_desc *desc;    /* the tree descriptor */

   529 #endif //__SYMBIAN32__

   530 {

   531     ct_data *tree        = desc->dyn_tree;

   532     int max_code         = desc->max_code;

   533     const ct_data *stree = desc->stat_desc->static_tree;

   534     const intf *extra    = desc->stat_desc->extra_bits;

   535     int base             = desc->stat_desc->extra_base;

   536     int max_length       = desc->stat_desc->max_length;

   537     int h;              /* heap index */

   538     int n, m;           /* iterate over the tree elements */

   539     int bits;           /* bit length */

   540     int xbits;          /* extra bits */

   541     ush f;              /* frequency */

   542     int overflow = 0;   /* number of elements with bit length too large */

   543 

   544     for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;

   545 

   546     /* In a first pass, compute the optimal bit lengths (which may

   547      * overflow in the case of the bit length tree).

   548      */

   549     tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */

   550 

   551     for (h = s->heap_max+1; h < HEAP_SIZE; h++) {

   552         n = s->heap[h];

   553         bits = tree[tree[n].Dad].Len + 1;

   554         if (bits > max_length) bits = max_length, overflow++;

   555         tree[n].Len = (ush)bits;

   556         /* We overwrite tree[n].Dad which is no longer needed */

   557 

   558         if (n > max_code) continue; /* not a leaf node */

   559 

   560         s->bl_count[bits]++;

   561         xbits = 0;

   562         if (n >= base) xbits = extra[n-base];

   563         f = tree[n].Freq;

   564         s->opt_len += (ulg)f * (bits + xbits);

   565         if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);

   566     }

   567     if (overflow == 0) return;

   568 

   569     Trace((stderr,"\nbit length overflow\n"));

   570     /* This happens for example on obj2 and pic of the Calgary corpus */

   571 

   572     /* Find the first bit length which could increase: */

   573     do {

   574         bits = max_length-1;

   575         while (s->bl_count[bits] == 0) bits--;

   576         s->bl_count[bits]--;      /* move one leaf down the tree */

   577         s->bl_count[bits+1] += 2; /* move one overflow item as its brother */

   578         s->bl_count[max_length]--;

   579         /* The brother of the overflow item also moves one step up,

   580          * but this does not affect bl_count[max_length]

   581          */

   582         overflow -= 2;

   583     } while (overflow > 0);

   584 

   585     /* Now recompute all bit lengths, scanning in increasing frequency.

   586      * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all

   587      * lengths instead of fixing only the wrong ones. This idea is taken

   588      * from 'ar' written by Haruhiko Okumura.)

   589      */

   590     for (bits = max_length; bits != 0; bits--) {

   591         n = s->bl_count[bits];

   592         while (n != 0) {

   593             m = s->heap[--h];

   594             if (m > max_code) continue;

   595             if ((unsigned) tree[m].Len != (unsigned) bits) {

   596                 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));

   597                 s->opt_len += ((long)bits - (long)tree[m].Len)

   598                               *(long)tree[m].Freq;

   599                 tree[m].Len = (ush)bits;

   600             }

   601             n--;

   602         }

   603     }

   604 }

   605 

   606 /* ===========================================================================

   607  * Generate the codes for a given tree and bit counts (which need not be

   608  * optimal).

   609  * IN assertion: the array bl_count contains the bit length statistics for

   610  * the given tree and the field len is set for all tree elements.

   611  * OUT assertion: the field code is set for all tree elements of non

   612  *     zero code length.

   613  */

   614 #ifdef __SYMBIAN32__

   615 local void gen_codes (    ct_data * tree, int max_code,    ushf *  bl_count)

   616 #else

   617 local void gen_codes (tree, max_code, bl_count)

   618     ct_data *tree;             /* the tree to decorate */

   619     int max_code;              /* largest code with non zero frequency */

   620     ushf *bl_count;            /* number of codes at each bit length */

   621 #endif //__SYMBIAN32__

   622 {

   623     ush next_code[MAX_BITS+1]; /* next code value for each bit length */

   624     ush code = 0;              /* running code value */

   625     int bits;                  /* bit index */

   626     int n;                     /* code index */

   627 

   628     /* The distribution counts are first used to generate the code values

   629      * without bit reversal.

   630      */

   631     for (bits = 1; bits <= MAX_BITS; bits++) {

   632         next_code[bits] = code = (code + bl_count[bits-1]) << 1;

   633     }

   634     /* Check that the bit counts in bl_count are consistent. The last code

   635      * must be all ones.

   636      */

   637     Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,

   638             "inconsistent bit counts");

   639     Tracev((stderr,"\ngen_codes: max_code %d ", max_code));

   640 

   641     for (n = 0;  n <= max_code; n++) {

   642         int len = tree[n].Len;

   643         if (len == 0) continue;

   644         /* Now reverse the bits */

   645         tree[n].Code = bi_reverse(next_code[len]++, len);

   646 

   647         Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",

   648              n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));

   649     }

   650 }

   651 

   652 /* ===========================================================================

   653  * Construct one Huffman tree and assigns the code bit strings and lengths.

   654  * Update the total bit length for the current block.

   655  * IN assertion: the field freq is set for all tree elements.

   656  * OUT assertions: the fields len and code are set to the optimal bit length

   657  *     and corresponding code. The length opt_len is updated; static_len is

   658  *     also updated if stree is not null. The field max_code is set.

   659  */

   660 #ifdef __SYMBIAN32__

   661 local void build_tree(    deflate_state * s,    tree_desc *  desc)

   662 #else

   663 local void build_tree(s, desc)

   664     deflate_state *s;

   665     tree_desc *desc; /* the tree descriptor */

   666 #endif //__SYMBIAN32__

   667 {

   668     ct_data *tree         = desc->dyn_tree;

   669     const ct_data *stree  = desc->stat_desc->static_tree;

   670     int elems             = desc->stat_desc->elems;

   671     int n, m;          /* iterate over heap elements */

   672     int max_code = -1; /* largest code with non zero frequency */

   673     int node;          /* new node being created */

   674 

   675     /* Construct the initial heap, with least frequent element in

   676      * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].

   677      * heap[0] is not used.

   678      */

   679     s->heap_len = 0, s->heap_max = HEAP_SIZE;

   680 

   681     for (n = 0; n < elems; n++) {

   682         if (tree[n].Freq != 0) {

   683             s->heap[++(s->heap_len)] = max_code = n;

   684             s->depth[n] = 0;

   685         } else {

   686             tree[n].Len = 0;

   687         }

   688     }

   689 

   690     /* The pkzip format requires that at least one distance code exists,

   691      * and that at least one bit should be sent even if there is only one

   692      * possible code. So to avoid special checks later on we force at least

   693      * two codes of non zero frequency.

   694      */

   695     while (s->heap_len < 2) {

   696         node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);

   697         tree[node].Freq = 1;

   698         s->depth[node] = 0;

   699         s->opt_len--; if (stree) s->static_len -= stree[node].Len;

   700         /* node is 0 or 1 so it does not have extra bits */

   701     }

   702     desc->max_code = max_code;

   703 

   704     /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,

   705      * establish sub-heaps of increasing lengths:

   706      */

   707     for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);

   708 

   709     /* Construct the Huffman tree by repeatedly combining the least two

   710      * frequent nodes.

   711      */

   712     node = elems;              /* next internal node of the tree */

   713     do {

   714         pqremove(s, tree, n);  /* n = node of least frequency */

   715         m = s->heap[SMALLEST]; /* m = node of next least frequency */

   716 

   717         s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */

   718         s->heap[--(s->heap_max)] = m;

   719 

   720         /* Create a new node father of n and m */

   721         tree[node].Freq = tree[n].Freq + tree[m].Freq;

   722         s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?

   723                                 s->depth[n] : s->depth[m]) + 1);

   724         tree[n].Dad = tree[m].Dad = (ush)node;

   725 #ifdef DUMP_BL_TREE

   726         if (tree == s->bl_tree) {

   727             fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",

   728                     node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);

   729         }

   730 #endif

   731         /* and insert the new node in the heap */

   732         s->heap[SMALLEST] = node++;

   733         pqdownheap(s, tree, SMALLEST);

   734 

   735     } while (s->heap_len >= 2);

   736 

   737     s->heap[--(s->heap_max)] = s->heap[SMALLEST];

   738 

   739     /* At this point, the fields freq and dad are set. We can now

   740      * generate the bit lengths.

   741      */

   742     gen_bitlen(s, (tree_desc *)desc);

   743 

   744     /* The field len is now set, we can generate the bit codes */

   745     gen_codes ((ct_data *)tree, max_code, s->bl_count);

   746 }

   747 

   748 /* ===========================================================================

   749  * Scan a literal or distance tree to determine the frequencies of the codes

   750  * in the bit length tree.

   751  */

   752  #ifdef __SYMBIAN32__

   753  local void scan_tree (   deflate_state * s,   ct_data *  tree,int  max_code)

   754  #else

   755 local void scan_tree (s, tree, max_code)

   756     deflate_state *s;

   757     ct_data *tree;   /* the tree to be scanned */

   758     int max_code;    /* and its largest code of non zero frequency */

   759 #endif //__SYMBIAN32__

   760 {

   761     int n;                     /* iterates over all tree elements */

   762     int prevlen = -1;          /* last emitted length */

   763     int curlen;                /* length of current code */

   764     int nextlen = tree[0].Len; /* length of next code */

   765     int count = 0;             /* repeat count of the current code */

   766     int max_count = 7;         /* max repeat count */

   767     int min_count = 4;         /* min repeat count */

   768 

   769     if (nextlen == 0) max_count = 138, min_count = 3;

   770     tree[max_code+1].Len = (ush)0xffff; /* guard */

   771 

   772     for (n = 0; n <= max_code; n++) {

   773         curlen = nextlen; nextlen = tree[n+1].Len;

   774         if (++count < max_count && curlen == nextlen) {

   775             continue;

   776         } else if (count < min_count) {

   777             s->bl_tree[curlen].Freq += count;

   778         } else if (curlen != 0) {

   779             if (curlen != prevlen) s->bl_tree[curlen].Freq++;

   780             s->bl_tree[REP_3_6].Freq++;

   781         } else if (count <= 10) {

   782             s->bl_tree[REPZ_3_10].Freq++;

   783         } else {

   784             s->bl_tree[REPZ_11_138].Freq++;

   785         }

   786         count = 0; prevlen = curlen;

   787         if (nextlen == 0) {

   788             max_count = 138, min_count = 3;

   789         } else if (curlen == nextlen) {

   790             max_count = 6, min_count = 3;

   791         } else {

   792             max_count = 7, min_count = 4;

   793         }

   794     }

   795 }

   796 

   797 /* ===========================================================================

   798  * Send a literal or distance tree in compressed form, using the codes in

   799  * bl_tree.

   800  */

   801 #ifdef __SYMBIAN32__

   802 local void send_tree (    deflate_state * s,    ct_data *  tree, int max_code)

   803 #else

   804 local void send_tree (s, tree, max_code)

   805     deflate_state *s;

   806     ct_data *tree; /* the tree to be scanned */

   807     int max_code;       /* and its largest code of non zero frequency */

   808 #endif //__SYMBIAN32__

   809 {

   810     int n;                     /* iterates over all tree elements */

   811     int prevlen = -1;          /* last emitted length */

   812     int curlen;                /* length of current code */

   813     int nextlen = tree[0].Len; /* length of next code */

   814     int count = 0;             /* repeat count of the current code */

   815     int max_count = 7;         /* max repeat count */

   816     int min_count = 4;         /* min repeat count */

   817 

   818     /* tree[max_code+1].Len = -1; */  /* guard already set */

   819     if (nextlen == 0) max_count = 138, min_count = 3;

   820 

   821     for (n = 0; n <= max_code; n++) {

   822         curlen = nextlen; nextlen = tree[n+1].Len;

   823         if (++count < max_count && curlen == nextlen) {

   824             continue;

   825         } else if (count < min_count) {

   826             do { send_code(s, curlen, s->bl_tree); } while (--count != 0);

   827 

   828         } else if (curlen != 0) {

   829             if (curlen != prevlen) {

   830                 send_code(s, curlen, s->bl_tree); count--;

   831             }

   832             Assert(count >= 3 && count <= 6, " 3_6?");

   833             send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);

   834 

   835         } else if (count <= 10) {

   836             send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);

   837 

   838         } else {

   839             send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);

   840         }

   841         count = 0; prevlen = curlen;

   842         if (nextlen == 0) {

   843             max_count = 138, min_count = 3;

   844         } else if (curlen == nextlen) {

   845             max_count = 6, min_count = 3;

   846         } else {

   847             max_count = 7, min_count = 4;

   848         }

   849     }

   850 }

   851 

   852 /* ===========================================================================

   853  * Construct the Huffman tree for the bit lengths and return the index in

   854  * bl_order of the last bit length code to send.

   855  */

   856 #ifdef __SYMBIAN32__

   857 local int build_bl_tree(  deflate_state * s)

   858 #else

   859 local int build_bl_tree(s)

   860     deflate_state *s;

   861 #endif //__SYMBIAN32__

   862 {

   863     int max_blindex;  /* index of last bit length code of non zero freq */

   864 

   865     /* Determine the bit length frequencies for literal and distance trees */

   866     scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);

   867     scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);

   868 

   869     /* Build the bit length tree: */

   870     build_tree(s, (tree_desc *)(&(s->bl_desc)));

   871     /* opt_len now includes the length of the tree representations, except

   872      * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.

   873      */

   874 

   875     /* Determine the number of bit length codes to send. The pkzip format

   876      * requires that at least 4 bit length codes be sent. (appnote.txt says

   877      * 3 but the actual value used is 4.)

   878      */

   879     for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {

   880         if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;

   881     }

   882     /* Update opt_len to include the bit length tree and counts */

   883     s->opt_len += 3*(max_blindex+1) + 5+5+4;

   884     Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",

   885             s->opt_len, s->static_len));

   886 

   887     return max_blindex;

   888 }

   889 

   890 /* ===========================================================================

   891  * Send the header for a block using dynamic Huffman trees: the counts, the

   892  * lengths of the bit length codes, the literal tree and the distance tree.

   893  * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.

   894  */

   895 #ifdef __SYMBIAN32__

   896 local void send_all_trees(   deflate_state * s, int lcodes, int dcodes, int blcodes)

   897 #else	

   898 local void send_all_trees(s, lcodes, dcodes, blcodes)

   899     deflate_state *s;

   900     int lcodes, dcodes, blcodes; /* number of codes for each tree */

   901 #endif //__SYMBIAN32__

   902 {

   903     int rank;                    /* index in bl_order */

   904 

   905     Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");

   906     Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,

   907             "too many codes");

   908     Tracev((stderr, "\nbl counts: "));

   909     send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */

   910     send_bits(s, dcodes-1,   5);

   911     send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */

   912     for (rank = 0; rank < blcodes; rank++) {

   913         Tracev((stderr, "\nbl code %2d ", bl_order[rank]));

   914         send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);

   915     }

   916     Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));

   917 

   918     send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */

   919     Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));

   920 

   921     send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */

   922     Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));

   923 }

   924 

   925 /* ===========================================================================

   926  * Send a stored block

   927  */

   928 #ifdef __SYMBIAN32__

   929 void _tr_stored_block(   deflate_state * s,    charf *  buf,ulg  stored_len, int eof)

   930 #else

   931 void _tr_stored_block(s, buf, stored_len, eof)

   932     deflate_state *s;

   933     charf *buf;       /* input block */

   934     ulg stored_len;   /* length of input block */

   935     int eof;          /* true if this is the last block for a file */

   936 #endif //__SYMBIAN32__	

   937 {

   938     send_bits(s, (STORED_BLOCK<<1)+eof, 3);  /* send block type */

   939 #ifdef DEBUG

   940     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;

   941     s->compressed_len += (stored_len + 4) << 3;

   942 #endif

   943     copy_block(s, buf, (unsigned)stored_len, 1); /* with header */

   944 }

   945 

   946 /* ===========================================================================

   947  * Send one empty static block to give enough lookahead for inflate.

   948  * This takes 10 bits, of which 7 may remain in the bit buffer.

   949  * The current inflate code requires 9 bits of lookahead. If the

   950  * last two codes for the previous block (real code plus EOB) were coded

   951  * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode

   952  * the last real code. In this case we send two empty static blocks instead

   953  * of one. (There are no problems if the previous block is stored or fixed.)

   954  * To simplify the code, we assume the worst case of last real code encoded

   955  * on one bit only.

   956  */

   957 #ifdef __SYMBIAN32__

   958 void _tr_align(    deflate_state * s)

   959 #else

   960 void _tr_align(s)

   961     deflate_state *s;

   962 #endif //__SYMBIAN32__

   963 {

   964     send_bits(s, STATIC_TREES<<1, 3);

   965     send_code(s, END_BLOCK, static_ltree);

   966 #ifdef DEBUG

   967     s->compressed_len += 10L; /* 3 for block type, 7 for EOB */

   968 #endif

   969     bi_flush(s);

   970     /* Of the 10 bits for the empty block, we have already sent

   971      * (10 - bi_valid) bits. The lookahead for the last real code (before

   972      * the EOB of the previous block) was thus at least one plus the length

   973      * of the EOB plus what we have just sent of the empty static block.

   974      */

   975     if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {

   976         send_bits(s, STATIC_TREES<<1, 3);

   977         send_code(s, END_BLOCK, static_ltree);

   978 #ifdef DEBUG

   979         s->compressed_len += 10L;

   980 #endif

   981         bi_flush(s);

   982     }

   983     s->last_eob_len = 7;

   984 }

   985 

   986 /* ===========================================================================

   987  * Determine the best encoding for the current block: dynamic trees, static

   988  * trees or store, and output the encoded block to the zip file.

   989  */

   990 #ifdef __SYMBIAN32__

   991 void _tr_flush_block(  deflate_state * s,    charf *  buf,ulg  stored_len,int  eof)

   992 #else

   993 void _tr_flush_block(s, buf, stored_len, eof)

   994     deflate_state *s;

   995     charf *buf;       /* input block, or NULL if too old */

   996     ulg stored_len;   /* length of input block */

   997     int eof;          /* true if this is the last block for a file */

   998 #endif //__SYMBIAN32__	

   999 {

  1000     ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */

  1001     int max_blindex = 0;  /* index of last bit length code of non zero freq */

  1002 

  1003     /* Build the Huffman trees unless a stored block is forced */

  1004     if (s->level > 0) {

  1005 

  1006         /* Check if the file is binary or text */

  1007         if (stored_len > 0 && s->strm->data_type == Z_UNKNOWN)

  1008             set_data_type(s);

  1009 

  1010         /* Construct the literal and distance trees */

  1011         build_tree(s, (tree_desc *)(&(s->l_desc)));

  1012         Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,

  1013                 s->static_len));

  1014 

  1015         build_tree(s, (tree_desc *)(&(s->d_desc)));

  1016         Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,

  1017                 s->static_len));

  1018         /* At this point, opt_len and static_len are the total bit lengths of

  1019          * the compressed block data, excluding the tree representations.

  1020          */

  1021 

  1022         /* Build the bit length tree for the above two trees, and get the index

  1023          * in bl_order of the last bit length code to send.

  1024          */

  1025         max_blindex = build_bl_tree(s);

  1026 

  1027         /* Determine the best encoding. Compute the block lengths in bytes. */

  1028         opt_lenb = (s->opt_len+3+7)>>3;

  1029         static_lenb = (s->static_len+3+7)>>3;

  1030 

  1031         Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",

  1032                 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,

  1033                 s->last_lit));

  1034 

  1035         if (static_lenb <= opt_lenb) opt_lenb = static_lenb;

  1036 

  1037     } else {

  1038         Assert(buf != (char*)0, "lost buf");

  1039         opt_lenb = static_lenb = stored_len + 5; /* force a stored block */

  1040     }

  1041 

  1042 #ifdef FORCE_STORED

  1043     if (buf != (char*)0) { /* force stored block */

  1044 #else

  1045     if (stored_len+4 <= opt_lenb && buf != (char*)0) {

  1046                        /* 4: two words for the lengths */

  1047 #endif

  1048         /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.

  1049          * Otherwise we can't have processed more than WSIZE input bytes since

  1050          * the last block flush, because compression would have been

  1051          * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to

  1052          * transform a block into a stored block.

  1053          */

  1054         _tr_stored_block(s, buf, stored_len, eof);

  1055 

  1056 #ifdef FORCE_STATIC

  1057     } else if (static_lenb >= 0) { /* force static trees */

  1058 #else

  1059     } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {

  1060 #endif

  1061         send_bits(s, (STATIC_TREES<<1)+eof, 3);

  1062         compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);

  1063 #ifdef DEBUG

  1064         s->compressed_len += 3 + s->static_len;

  1065 #endif

  1066     } else {

  1067         send_bits(s, (DYN_TREES<<1)+eof, 3);

  1068         send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,

  1069                        max_blindex+1);

  1070         compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);

  1071 #ifdef DEBUG

  1072         s->compressed_len += 3 + s->opt_len;

  1073 #endif

  1074     }

  1075     Assert (s->compressed_len == s->bits_sent, "bad compressed size");

  1076     /* The above check is made mod 2^32, for files larger than 512 MB

  1077      * and uLong implemented on 32 bits.

  1078      */

  1079     init_block(s);

  1080 

  1081     if (eof) {

  1082         bi_windup(s);

  1083 #ifdef DEBUG

  1084         s->compressed_len += 7;  /* align on byte boundary */

  1085 #endif

  1086     }

  1087     Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,

  1088            s->compressed_len-7*eof));

  1089 }

  1090 

  1091 /* ===========================================================================

  1092  * Save the match info and tally the frequency counts. Return true if

  1093  * the current block must be flushed.

  1094  */

  1095 #ifndef SYMBIAN_EZLIB_DEVICE

  1096 

  1097 #ifdef __SYMBIAN32__

  1098 int _tr_tally (   deflate_state * s,unsigned  dist,unsigned  lc)

  1099 #else

  1100 int _tr_tally (s, dist, lc)

  1101     deflate_state *s;

  1102     unsigned dist;  /* distance of matched string */

  1103     unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */

  1104 #endif //__SYMBIAN32__

  1105 {

  1106     s->d_buf[s->last_lit] = (ush)dist;

  1107     s->l_buf[s->last_lit++] = (uch)lc;

  1108     if (dist == 0) {

  1109         /* lc is the unmatched char */

  1110         s->dyn_ltree[lc].Freq++;

  1111     } else {

  1112         s->matches++;

  1113         /* Here, lc is the match length - MIN_MATCH */

  1114         dist--;             /* dist = match distance - 1 */

  1115         Assert((ush)dist < (ush)MAX_DIST(s) &&

  1116                (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&

  1117                (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");

  1118 

  1119         s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;

  1120         s->dyn_dtree[d_code(dist)].Freq++;

  1121     }

  1122 

  1123 #ifdef TRUNCATE_BLOCK

  1124     /* Try to guess if it is profitable to stop the current block here */

  1125     if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {

  1126         /* Compute an upper bound for the compressed length */

  1127         ulg out_length = (ulg)s->last_lit*8L;

  1128         ulg in_length = (ulg)((long)s->strstart - s->block_start);

  1129         int dcode;

  1130         for (dcode = 0; dcode < D_CODES; dcode++) {

  1131             out_length += (ulg)s->dyn_dtree[dcode].Freq *

  1132                 (5L+extra_dbits[dcode]);

  1133         }

  1134         out_length >>= 3;

  1135         Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",