LCOV - code coverage report
Current view: directory - modules/zlib/src - trees.c (source / functions) Found Hit Coverage
Test: app.info Lines: 306 261 85.3 %
Date: 2012-06-02 Functions: 21 16 76.2 %

       1                 : /* trees.c -- output deflated data using Huffman coding
       2                 :  * Copyright (C) 1995-2010 Jean-loup Gailly
       3                 :  * detect_data_type() function provided freely by Cosmin Truta, 2006
       4                 :  * For conditions of distribution and use, see copyright notice in zlib.h
       5                 :  */
       6                 : 
       7                 : /*
       8                 :  *  ALGORITHM
       9                 :  *
      10                 :  *      The "deflation" process uses several Huffman trees. The more
      11                 :  *      common source values are represented by shorter bit sequences.
      12                 :  *
      13                 :  *      Each code tree is stored in a compressed form which is itself
      14                 :  * a Huffman encoding of the lengths of all the code strings (in
      15                 :  * ascending order by source values).  The actual code strings are
      16                 :  * reconstructed from the lengths in the inflate process, as described
      17                 :  * in the deflate specification.
      18                 :  *
      19                 :  *  REFERENCES
      20                 :  *
      21                 :  *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
      22                 :  *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
      23                 :  *
      24                 :  *      Storer, James A.
      25                 :  *          Data Compression:  Methods and Theory, pp. 49-50.
      26                 :  *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
      27                 :  *
      28                 :  *      Sedgewick, R.
      29                 :  *          Algorithms, p290.
      30                 :  *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
      31                 :  */
      32                 : 
      33                 : /* @(#) $Id$ */
      34                 : 
      35                 : /* #define GEN_TREES_H */
      36                 : 
      37                 : #include "deflate.h"
      38                 : 
      39                 : #ifdef DEBUG
      40                 : #  include <ctype.h>
      41                 : #endif
      42                 : 
      43                 : /* ===========================================================================
      44                 :  * Constants
      45                 :  */
      46                 : 
      47                 : #define MAX_BL_BITS 7
      48                 : /* Bit length codes must not exceed MAX_BL_BITS bits */
      49                 : 
      50                 : #define END_BLOCK 256
      51                 : /* end of block literal code */
      52                 : 
      53                 : #define REP_3_6      16
      54                 : /* repeat previous bit length 3-6 times (2 bits of repeat count) */
      55                 : 
      56                 : #define REPZ_3_10    17
      57                 : /* repeat a zero length 3-10 times  (3 bits of repeat count) */
      58                 : 
      59                 : #define REPZ_11_138  18
      60                 : /* repeat a zero length 11-138 times  (7 bits of repeat count) */
      61                 : 
      62                 : local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
      63                 :    = {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};
      64                 : 
      65                 : local const int extra_dbits[D_CODES] /* extra bits for each distance code */
      66                 :    = {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};
      67                 : 
      68                 : local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
      69                 :    = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
      70                 : 
      71                 : local const uch bl_order[BL_CODES]
      72                 :    = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
      73                 : /* The lengths of the bit length codes are sent in order of decreasing
      74                 :  * probability, to avoid transmitting the lengths for unused bit length codes.
      75                 :  */
      76                 : 
      77                 : #define Buf_size (8 * 2*sizeof(char))
      78                 : /* Number of bits used within bi_buf. (bi_buf might be implemented on
      79                 :  * more than 16 bits on some systems.)
      80                 :  */
      81                 : 
      82                 : /* ===========================================================================
      83                 :  * Local data. These are initialized only once.
      84                 :  */
      85                 : 
      86                 : #define DIST_CODE_LEN  512 /* see definition of array dist_code below */
      87                 : 
      88                 : #if defined(GEN_TREES_H) || !defined(STDC)
      89                 : /* non ANSI compilers may not accept trees.h */
      90                 : 
      91                 : local ct_data static_ltree[L_CODES+2];
      92                 : /* The static literal tree. Since the bit lengths are imposed, there is no
      93                 :  * need for the L_CODES extra codes used during heap construction. However
      94                 :  * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
      95                 :  * below).
      96                 :  */
      97                 : 
      98                 : local ct_data static_dtree[D_CODES];
      99                 : /* The static distance tree. (Actually a trivial tree since all codes use
     100                 :  * 5 bits.)
     101                 :  */
     102                 : 
     103                 : uch _dist_code[DIST_CODE_LEN];
     104                 : /* Distance codes. The first 256 values correspond to the distances
     105                 :  * 3 .. 258, the last 256 values correspond to the top 8 bits of
     106                 :  * the 15 bit distances.
     107                 :  */
     108                 : 
     109                 : uch _length_code[MAX_MATCH-MIN_MATCH+1];
     110                 : /* length code for each normalized match length (0 == MIN_MATCH) */
     111                 : 
     112                 : local int base_length[LENGTH_CODES];
     113                 : /* First normalized length for each code (0 = MIN_MATCH) */
     114                 : 
     115                 : local int base_dist[D_CODES];
     116                 : /* First normalized distance for each code (0 = distance of 1) */
     117                 : 
     118                 : #else
     119                 : #  include "trees.h"
     120                 : #endif /* GEN_TREES_H */
     121                 : 
     122                 : struct static_tree_desc_s {
     123                 :     const ct_data *static_tree;  /* static tree or NULL */
     124                 :     const intf *extra_bits;      /* extra bits for each code or NULL */
     125                 :     int     extra_base;          /* base index for extra_bits */
     126                 :     int     elems;               /* max number of elements in the tree */
     127                 :     int     max_length;          /* max bit length for the codes */
     128                 : };
     129                 : 
     130                 : local static_tree_desc  static_l_desc =
     131                 : {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
     132                 : 
     133                 : local static_tree_desc  static_d_desc =
     134                 : {static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
     135                 : 
     136                 : local static_tree_desc  static_bl_desc =
     137                 : {(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};
     138                 : 
     139                 : /* ===========================================================================
     140                 :  * Local (static) routines in this file.
     141                 :  */
     142                 : 
     143                 : local void tr_static_init OF((void));
     144                 : local void init_block     OF((deflate_state *s));
     145                 : local void pqdownheap     OF((deflate_state *s, ct_data *tree, int k));
     146                 : local void gen_bitlen     OF((deflate_state *s, tree_desc *desc));
     147                 : local void gen_codes      OF((ct_data *tree, int max_code, ushf *bl_count));
     148                 : local void build_tree     OF((deflate_state *s, tree_desc *desc));
     149                 : local void scan_tree      OF((deflate_state *s, ct_data *tree, int max_code));
     150                 : local void send_tree      OF((deflate_state *s, ct_data *tree, int max_code));
     151                 : local int  build_bl_tree  OF((deflate_state *s));
     152                 : local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
     153                 :                               int blcodes));
     154                 : local void compress_block OF((deflate_state *s, ct_data *ltree,
     155                 :                               ct_data *dtree));
     156                 : local int  detect_data_type OF((deflate_state *s));
     157                 : local unsigned bi_reverse OF((unsigned value, int length));
     158                 : local void bi_windup      OF((deflate_state *s));
     159                 : local void bi_flush       OF((deflate_state *s));
     160                 : local void copy_block     OF((deflate_state *s, charf *buf, unsigned len,
     161                 :                               int header));
     162                 : 
     163                 : #ifdef GEN_TREES_H
     164                 : local void gen_trees_header OF((void));
     165                 : #endif
     166                 : 
     167                 : #ifndef DEBUG
     168                 : #  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
     169                 :    /* Send a code of the given tree. c and tree must not have side effects */
     170                 : 
     171                 : #else /* DEBUG */
     172                 : #  define send_code(s, c, tree) \
     173                 :      { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
     174                 :        send_bits(s, tree[c].Code, tree[c].Len); }
     175                 : #endif
     176                 : 
     177                 : /* ===========================================================================
     178                 :  * Output a short LSB first on the stream.
     179                 :  * IN assertion: there is enough room in pendingBuf.
     180                 :  */
     181                 : #define put_short(s, w) { \
     182                 :     put_byte(s, (uch)((w) & 0xff)); \
     183                 :     put_byte(s, (uch)((ush)(w) >> 8)); \
     184                 : }
     185                 : 
     186                 : /* ===========================================================================
     187                 :  * Send a value on a given number of bits.
     188                 :  * IN assertion: length <= 16 and value fits in length bits.
     189                 :  */
     190                 : #ifdef DEBUG
     191                 : local void send_bits      OF((deflate_state *s, int value, int length));
     192                 : 
     193                 : local void send_bits(s, value, length)
     194                 :     deflate_state *s;
     195                 :     int value;  /* value to send */
     196                 :     int length; /* number of bits */
     197                 : {
     198                 :     Tracevv((stderr," l %2d v %4x ", length, value));
     199                 :     Assert(length > 0 && length <= 15, "invalid length");
     200                 :     s->bits_sent += (ulg)length;
     201                 : 
     202                 :     /* If not enough room in bi_buf, use (valid) bits from bi_buf and
     203                 :      * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
     204                 :      * unused bits in value.
     205                 :      */
     206                 :     if (s->bi_valid > (int)Buf_size - length) {
     207                 :         s->bi_buf |= (ush)value << s->bi_valid;
     208                 :         put_short(s, s->bi_buf);
     209                 :         s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
     210                 :         s->bi_valid += length - Buf_size;
     211                 :     } else {
     212                 :         s->bi_buf |= (ush)value << s->bi_valid;
     213                 :         s->bi_valid += length;
     214                 :     }
     215                 : }
     216                 : #else /* !DEBUG */
     217                 : 
     218                 : #define send_bits(s, value, length) \
     219                 : { int len = length;\
     220                 :   if (s->bi_valid > (int)Buf_size - len) {\
     221                 :     int val = value;\
     222                 :     s->bi_buf |= (ush)val << s->bi_valid;\
     223                 :     put_short(s, s->bi_buf);\
     224                 :     s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
     225                 :     s->bi_valid += len - Buf_size;\
     226                 :   } else {\
     227                 :     s->bi_buf |= (ush)(value) << s->bi_valid;\
     228                 :     s->bi_valid += len;\
     229                 :   }\
     230                 : }
     231                 : #endif /* DEBUG */
     232                 : 
     233                 : 
     234                 : /* the arguments must not have side effects */
     235                 : 
     236                 : /* ===========================================================================
     237                 :  * Initialize the various 'constant' tables.
     238                 :  */
     239            5217 : local void tr_static_init()
     240                 : {
     241                 : #if defined(GEN_TREES_H) || !defined(STDC)
     242                 :     static int static_init_done = 0;
     243                 :     int n;        /* iterates over tree elements */
     244                 :     int bits;     /* bit counter */
     245                 :     int length;   /* length value */
     246                 :     int code;     /* code value */
     247                 :     int dist;     /* distance index */
     248                 :     ush bl_count[MAX_BITS+1];
     249                 :     /* number of codes at each bit length for an optimal tree */
     250                 : 
     251                 :     if (static_init_done) return;
     252                 : 
     253                 :     /* For some embedded targets, global variables are not initialized: */
     254                 : #ifdef NO_INIT_GLOBAL_POINTERS
     255                 :     static_l_desc.static_tree = static_ltree;
     256                 :     static_l_desc.extra_bits = extra_lbits;
     257                 :     static_d_desc.static_tree = static_dtree;
     258                 :     static_d_desc.extra_bits = extra_dbits;
     259                 :     static_bl_desc.extra_bits = extra_blbits;
     260                 : #endif
     261                 : 
     262                 :     /* Initialize the mapping length (0..255) -> length code (0..28) */
     263                 :     length = 0;
     264                 :     for (code = 0; code < LENGTH_CODES-1; code++) {
     265                 :         base_length[code] = length;
     266                 :         for (n = 0; n < (1<<extra_lbits[code]); n++) {
     267                 :             _length_code[length++] = (uch)code;
     268                 :         }
     269                 :     }
     270                 :     Assert (length == 256, "tr_static_init: length != 256");
     271                 :     /* Note that the length 255 (match length 258) can be represented
     272                 :      * in two different ways: code 284 + 5 bits or code 285, so we
     273                 :      * overwrite length_code[255] to use the best encoding:
     274                 :      */
     275                 :     _length_code[length-1] = (uch)code;
     276                 : 
     277                 :     /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
     278                 :     dist = 0;
     279                 :     for (code = 0 ; code < 16; code++) {
     280                 :         base_dist[code] = dist;
     281                 :         for (n = 0; n < (1<<extra_dbits[code]); n++) {
     282                 :             _dist_code[dist++] = (uch)code;
     283                 :         }
     284                 :     }
     285                 :     Assert (dist == 256, "tr_static_init: dist != 256");
     286                 :     dist >>= 7; /* from now on, all distances are divided by 128 */
     287                 :     for ( ; code < D_CODES; code++) {
     288                 :         base_dist[code] = dist << 7;
     289                 :         for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
     290                 :             _dist_code[256 + dist++] = (uch)code;
     291                 :         }
     292                 :     }
     293                 :     Assert (dist == 256, "tr_static_init: 256+dist != 512");
     294                 : 
     295                 :     /* Construct the codes of the static literal tree */
     296                 :     for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
     297                 :     n = 0;
     298                 :     while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
     299                 :     while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
     300                 :     while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
     301                 :     while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
     302                 :     /* Codes 286 and 287 do not exist, but we must include them in the
     303                 :      * tree construction to get a canonical Huffman tree (longest code
     304                 :      * all ones)
     305                 :      */
     306                 :     gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
     307                 : 
     308                 :     /* The static distance tree is trivial: */
     309                 :     for (n = 0; n < D_CODES; n++) {
     310                 :         static_dtree[n].Len = 5;
     311                 :         static_dtree[n].Code = bi_reverse((unsigned)n, 5);
     312                 :     }
     313                 :     static_init_done = 1;
     314                 : 
     315                 : #  ifdef GEN_TREES_H
     316                 :     gen_trees_header();
     317                 : #  endif
     318                 : #endif /* defined(GEN_TREES_H) || !defined(STDC) */
     319            5217 : }
     320                 : 
     321                 : /* ===========================================================================
     322                 :  * Genererate the file trees.h describing the static trees.
     323                 :  */
     324                 : #ifdef GEN_TREES_H
     325                 : #  ifndef DEBUG
     326                 : #    include <stdio.h>
     327                 : #  endif
     328                 : 
     329                 : #  define SEPARATOR(i, last, width) \
     330                 :       ((i) == (last)? "\n};\n\n" :    \
     331                 :        ((i) % (width) == (width)-1 ? ",\n" : ", "))
     332                 : 
     333                 : void gen_trees_header()
     334                 : {
     335                 :     FILE *header = fopen("trees.h", "w");
     336                 :     int i;
     337                 : 
     338                 :     Assert (header != NULL, "Can't open trees.h");
     339                 :     fprintf(header,
     340                 :             "/* header created automatically with -DGEN_TREES_H */\n\n");
     341                 : 
     342                 :     fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
     343                 :     for (i = 0; i < L_CODES+2; i++) {
     344                 :         fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
     345                 :                 static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
     346                 :     }
     347                 : 
     348                 :     fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
     349                 :     for (i = 0; i < D_CODES; i++) {
     350                 :         fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
     351                 :                 static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
     352                 :     }
     353                 : 
     354                 :     fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
     355                 :     for (i = 0; i < DIST_CODE_LEN; i++) {
     356                 :         fprintf(header, "%2u%s", _dist_code[i],
     357                 :                 SEPARATOR(i, DIST_CODE_LEN-1, 20));
     358                 :     }
     359                 : 
     360                 :     fprintf(header,
     361                 :         "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
     362                 :     for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
     363                 :         fprintf(header, "%2u%s", _length_code[i],
     364                 :                 SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
     365                 :     }
     366                 : 
     367                 :     fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
     368                 :     for (i = 0; i < LENGTH_CODES; i++) {
     369                 :         fprintf(header, "%1u%s", base_length[i],
     370                 :                 SEPARATOR(i, LENGTH_CODES-1, 20));
     371                 :     }
     372                 : 
     373                 :     fprintf(header, "local const int base_dist[D_CODES] = {\n");
     374                 :     for (i = 0; i < D_CODES; i++) {
     375                 :         fprintf(header, "%5u%s", base_dist[i],
     376                 :                 SEPARATOR(i, D_CODES-1, 10));
     377                 :     }
     378                 : 
     379                 :     fclose(header);
     380                 : }
     381                 : #endif /* GEN_TREES_H */
     382                 : 
     383                 : /* ===========================================================================
     384                 :  * Initialize the tree data structures for a new zlib stream.
     385                 :  */
     386            5217 : void ZLIB_INTERNAL _tr_init(s)
     387                 :     deflate_state *s;
     388                 : {
     389            5217 :     tr_static_init();
     390                 : 
     391            5217 :     s->l_desc.dyn_tree = s->dyn_ltree;
     392            5217 :     s->l_desc.stat_desc = &static_l_desc;
     393                 : 
     394            5217 :     s->d_desc.dyn_tree = s->dyn_dtree;
     395            5217 :     s->d_desc.stat_desc = &static_d_desc;
     396                 : 
     397            5217 :     s->bl_desc.dyn_tree = s->bl_tree;
     398            5217 :     s->bl_desc.stat_desc = &static_bl_desc;
     399                 : 
     400            5217 :     s->bi_buf = 0;
     401            5217 :     s->bi_valid = 0;
     402            5217 :     s->last_eob_len = 8; /* enough lookahead for inflate */
     403                 : #ifdef DEBUG
     404                 :     s->compressed_len = 0L;
     405                 :     s->bits_sent = 0L;
     406                 : #endif
     407                 : 
     408                 :     /* Initialize the first block of the first file: */
     409            5217 :     init_block(s);
     410            5217 : }
     411                 : 
     412                 : /* ===========================================================================
     413                 :  * Initialize a new block.
     414                 :  */
     415           12985 : local void init_block(s)
     416                 :     deflate_state *s;
     417                 : {
     418                 :     int n; /* iterates over tree elements */
     419                 : 
     420                 :     /* Initialize the trees. */
     421           12985 :     for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
     422           12985 :     for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
     423           12985 :     for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
     424                 : 
     425           12985 :     s->dyn_ltree[END_BLOCK].Freq = 1;
     426           12985 :     s->opt_len = s->static_len = 0L;
     427           12985 :     s->last_lit = s->matches = 0;
     428           12985 : }
     429                 : 
     430                 : #define SMALLEST 1
     431                 : /* Index within the heap array of least frequent node in the Huffman tree */
     432                 : 
     433                 : 
     434                 : /* ===========================================================================
     435                 :  * Remove the smallest element from the heap and recreate the heap with
     436                 :  * one less element. Updates heap and heap_len.
     437                 :  */
     438                 : #define pqremove(s, tree, top) \
     439                 : {\
     440                 :     top = s->heap[SMALLEST]; \
     441                 :     s->heap[SMALLEST] = s->heap[s->heap_len--]; \
     442                 :     pqdownheap(s, tree, SMALLEST); \
     443                 : }
     444                 : 
     445                 : /* ===========================================================================
     446                 :  * Compares to subtrees, using the tree depth as tie breaker when
     447                 :  * the subtrees have equal frequency. This minimizes the worst case length.
     448                 :  */
     449                 : #define smaller(tree, n, m, depth) \
     450                 :    (tree[n].Freq < tree[m].Freq || \
     451                 :    (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
     452                 : 
     453                 : /* ===========================================================================
     454                 :  * Restore the heap property by moving down the tree starting at node k,
     455                 :  * exchanging a node with the smallest of its two sons if necessary, stopping
     456                 :  * when the heap property is re-established (each father smaller than its
     457                 :  * two sons).
     458                 :  */
     459         5585638 : local void pqdownheap(s, tree, k)
     460                 :     deflate_state *s;
     461                 :     ct_data *tree;  /* the tree to restore */
     462                 :     int k;               /* node to move down */
     463                 : {
     464         5585638 :     int v = s->heap[k];
     465         5585638 :     int j = k << 1;  /* left son of k */
     466        34757997 :     while (j <= s->heap_len) {
     467                 :         /* Set j to the smallest of the two sons: */
     468        49543740 :         if (j < s->heap_len &&
     469        42838401 :             smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
     470        11868369 :             j++;
     471                 :         }
     472                 :         /* Exit if v is smaller than both sons */
     473        24904453 :         if (smaller(tree, v, s->heap[j], s->depth)) break;
     474                 : 
     475                 :         /* Exchange v with the smallest son */
     476        23586721 :         s->heap[k] = s->heap[j];  k = j;
     477                 : 
     478                 :         /* And continue down the tree, setting j to the left son of k */
     479        23586721 :         j <<= 1;
     480                 :     }
     481         5585638 :     s->heap[k] = v;
     482         5585638 : }
     483                 : 
     484                 : /* ===========================================================================
     485                 :  * Compute the optimal bit lengths for a tree and update the total bit length
     486                 :  * for the current block.
     487                 :  * IN assertion: the fields freq and dad are set, heap[heap_max] and
     488                 :  *    above are the tree nodes sorted by increasing frequency.
     489                 :  * OUT assertions: the field len is set to the optimal bit length, the
     490                 :  *     array bl_count contains the frequencies for each bit length.
     491                 :  *     The length opt_len is updated; static_len is also updated if stree is
     492                 :  *     not null.
     493                 :  */
     494           23304 : local void gen_bitlen(s, desc)
     495                 :     deflate_state *s;
     496                 :     tree_desc *desc;    /* the tree descriptor */
     497                 : {
     498           23304 :     ct_data *tree        = desc->dyn_tree;
     499           23304 :     int max_code         = desc->max_code;
     500           23304 :     const ct_data *stree = desc->stat_desc->static_tree;
     501           23304 :     const intf *extra    = desc->stat_desc->extra_bits;
     502           23304 :     int base             = desc->stat_desc->extra_base;
     503           23304 :     int max_length       = desc->stat_desc->max_length;
     504                 :     int h;              /* heap index */
     505                 :     int n, m;           /* iterate over the tree elements */
     506                 :     int bits;           /* bit length */
     507                 :     int xbits;          /* extra bits */
     508                 :     ush f;              /* frequency */
     509           23304 :     int overflow = 0;   /* number of elements with bit length too large */
     510                 : 
     511           23304 :     for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
     512                 : 
     513                 :     /* In a first pass, compute the optimal bit lengths (which may
     514                 :      * overflow in the case of the bit length tree).
     515                 :      */
     516           23304 :     tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
     517                 : 
     518         4486460 :     for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
     519         4463156 :         n = s->heap[h];
     520         4463156 :         bits = tree[tree[n].Dad].Len + 1;
     521         4463156 :         if (bits > max_length) bits = max_length, overflow++;
     522         4463156 :         tree[n].Len = (ush)bits;
     523                 :         /* We overwrite tree[n].Dad which is no longer needed */
     524                 : 
     525         4463156 :         if (n > max_code) continue; /* not a leaf node */
     526                 : 
     527         2254882 :         s->bl_count[bits]++;
     528         2254882 :         xbits = 0;
     529         2254882 :         if (n >= base) xbits = extra[n-base];
     530         2254882 :         f = tree[n].Freq;
     531         2254882 :         s->opt_len += (ulg)f * (bits + xbits);
     532         2254882 :         if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
     533                 :     }
     534           23304 :     if (overflow == 0) return;
     535                 : 
     536                 :     Trace((stderr,"\nbit length overflow\n"));
     537                 :     /* This happens for example on obj2 and pic of the Calgary corpus */
     538                 : 
     539                 :     /* Find the first bit length which could increase: */
     540                 :     do {
     541            1610 :         bits = max_length-1;
     542            1610 :         while (s->bl_count[bits] == 0) bits--;
     543            1610 :         s->bl_count[bits]--;      /* move one leaf down the tree */
     544            1610 :         s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
     545            1610 :         s->bl_count[max_length]--;
     546                 :         /* The brother of the overflow item also moves one step up,
     547                 :          * but this does not affect bl_count[max_length]
     548                 :          */
     549            1610 :         overflow -= 2;
     550            1610 :     } while (overflow > 0);
     551                 : 
     552                 :     /* Now recompute all bit lengths, scanning in increasing frequency.
     553                 :      * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
     554                 :      * lengths instead of fixing only the wrong ones. This idea is taken
     555                 :      * from 'ar' written by Haruhiko Okumura.)
     556                 :      */
     557           11672 :     for (bits = max_length; bits != 0; bits--) {
     558           10213 :         n = s->bl_count[bits];
     559           52677 :         while (n != 0) {
     560           32251 :             m = s->heap[--h];
     561           32251 :             if (m > max_code) continue;
     562           20973 :             if ((unsigned) tree[m].Len != (unsigned) bits) {
     563                 :                 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
     564            2982 :                 s->opt_len += ((long)bits - (long)tree[m].Len)
     565            1491 :                               *(long)tree[m].Freq;
     566            1491 :                 tree[m].Len = (ush)bits;
     567                 :             }
     568           20973 :             n--;
     569                 :         }
     570                 :     }
     571                 : }
     572                 : 
     573                 : /* ===========================================================================
     574                 :  * Generate the codes for a given tree and bit counts (which need not be
     575                 :  * optimal).
     576                 :  * IN assertion: the array bl_count contains the bit length statistics for
     577                 :  * the given tree and the field len is set for all tree elements.
     578                 :  * OUT assertion: the field code is set for all tree elements of non
     579                 :  *     zero code length.
     580                 :  */
     581           23304 : local void gen_codes (tree, max_code, bl_count)
     582                 :     ct_data *tree;             /* the tree to decorate */
     583                 :     int max_code;              /* largest code with non zero frequency */
     584                 :     ushf *bl_count;            /* number of codes at each bit length */
     585                 : {
     586                 :     ush next_code[MAX_BITS+1]; /* next code value for each bit length */
     587           23304 :     ush code = 0;              /* running code value */
     588                 :     int bits;                  /* bit index */
     589                 :     int n;                     /* code index */
     590                 : 
     591                 :     /* The distribution counts are first used to generate the code values
     592                 :      * without bit reversal.
     593                 :      */
     594          372864 :     for (bits = 1; bits <= MAX_BITS; bits++) {
     595          349560 :         next_code[bits] = code = (code + bl_count[bits-1]) << 1;
     596                 :     }
     597                 :     /* Check that the bit counts in bl_count are consistent. The last code
     598                 :      * must be all ones.
     599                 :      */
     600                 :     Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
     601                 :             "inconsistent bit counts");
     602                 :     Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
     603                 : 
     604         2595695 :     for (n = 0;  n <= max_code; n++) {
     605         2572391 :         int len = tree[n].Len;
     606         2572391 :         if (len == 0) continue;
     607                 :         /* Now reverse the bits */
     608         2254882 :         tree[n].Code = bi_reverse(next_code[len]++, len);
     609                 : 
     610                 :         Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
     611                 :              n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
     612                 :     }
     613           23304 : }
     614                 : 
     615                 : /* ===========================================================================
     616                 :  * Construct one Huffman tree and assigns the code bit strings and lengths.
     617                 :  * Update the total bit length for the current block.
     618                 :  * IN assertion: the field freq is set for all tree elements.
     619                 :  * OUT assertions: the fields len and code are set to the optimal bit length
     620                 :  *     and corresponding code. The length opt_len is updated; static_len is
     621                 :  *     also updated if stree is not null. The field max_code is set.
     622                 :  */
     623           23304 : local void build_tree(s, desc)
     624                 :     deflate_state *s;
     625                 :     tree_desc *desc; /* the tree descriptor */
     626                 : {
     627           23304 :     ct_data *tree         = desc->dyn_tree;
     628           23304 :     const ct_data *stree  = desc->stat_desc->static_tree;
     629           23304 :     int elems             = desc->stat_desc->elems;
     630                 :     int n, m;          /* iterate over heap elements */
     631           23304 :     int max_code = -1; /* largest code with non zero frequency */
     632                 :     int node;          /* new node being created */
     633                 : 
     634                 :     /* Construct the initial heap, with least frequent element in
     635                 :      * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
     636                 :      * heap[0] is not used.
     637                 :      */
     638           23304 :     s->heap_len = 0, s->heap_max = HEAP_SIZE;
     639                 : 
     640         2625584 :     for (n = 0; n < elems; n++) {
     641         2602280 :         if (tree[n].Freq != 0) {
     642         2254858 :             s->heap[++(s->heap_len)] = max_code = n;
     643         2254858 :             s->depth[n] = 0;
     644                 :         } else {
     645          347422 :             tree[n].Len = 0;
     646                 :         }
     647                 :     }
     648                 : 
     649                 :     /* The pkzip format requires that at least one distance code exists,
     650                 :      * and that at least one bit should be sent even if there is only one
     651                 :      * possible code. So to avoid special checks later on we force at least
     652                 :      * two codes of non zero frequency.
     653                 :      */
     654           46632 :     while (s->heap_len < 2) {
     655              24 :         node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
     656              24 :         tree[node].Freq = 1;
     657              24 :         s->depth[node] = 0;
     658              24 :         s->opt_len--; if (stree) s->static_len -= stree[node].Len;
     659                 :         /* node is 0 or 1 so it does not have extra bits */
     660                 :     }
     661           23304 :     desc->max_code = max_code;
     662                 : 
     663                 :     /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
     664                 :      * establish sub-heaps of increasing lengths:
     665                 :      */
     666           23304 :     for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
     667                 : 
     668                 :     /* Construct the Huffman tree by repeatedly combining the least two
     669                 :      * frequent nodes.
     670                 :      */
     671           23304 :     node = elems;              /* next internal node of the tree */
     672                 :     do {
     673         2231578 :         pqremove(s, tree, n);  /* n = node of least frequency */
     674         2231578 :         m = s->heap[SMALLEST]; /* m = node of next least frequency */
     675                 : 
     676         2231578 :         s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
     677         2231578 :         s->heap[--(s->heap_max)] = m;
     678                 : 
     679                 :         /* Create a new node father of n and m */
     680         2231578 :         tree[node].Freq = tree[n].Freq + tree[m].Freq;
     681         4463156 :         s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
     682         2231578 :                                 s->depth[n] : s->depth[m]) + 1);
     683         2231578 :         tree[n].Dad = tree[m].Dad = (ush)node;
     684                 : #ifdef DUMP_BL_TREE
     685                 :         if (tree == s->bl_tree) {
     686                 :             fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
     687                 :                     node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
     688                 :         }
     689                 : #endif
     690                 :         /* and insert the new node in the heap */
     691         2231578 :         s->heap[SMALLEST] = node++;
     692         2231578 :         pqdownheap(s, tree, SMALLEST);
     693                 : 
     694         2231578 :     } while (s->heap_len >= 2);
     695                 : 
     696           23304 :     s->heap[--(s->heap_max)] = s->heap[SMALLEST];
     697                 : 
     698                 :     /* At this point, the fields freq and dad are set. We can now
     699                 :      * generate the bit lengths.
     700                 :      */
     701           23304 :     gen_bitlen(s, (tree_desc *)desc);
     702                 : 
     703                 :     /* The field len is now set, we can generate the bit codes */
     704           23304 :     gen_codes ((ct_data *)tree, max_code, s->bl_count);
     705           23304 : }
     706                 : 
     707                 : /* ===========================================================================
     708                 :  * Scan a literal or distance tree to determine the frequencies of the codes
     709                 :  * in the bit length tree.
     710                 :  */
     711           15536 : local void scan_tree (s, tree, max_code)
     712                 :     deflate_state *s;
     713                 :     ct_data *tree;   /* the tree to be scanned */
     714                 :     int max_code;    /* and its largest code of non zero frequency */
     715                 : {
     716                 :     int n;                     /* iterates over all tree elements */
     717           15536 :     int prevlen = -1;          /* last emitted length */
     718                 :     int curlen;                /* length of current code */
     719           15536 :     int nextlen = tree[0].Len; /* length of next code */
     720           15536 :     int count = 0;             /* repeat count of the current code */
     721           15536 :     int max_count = 7;         /* max repeat count */
     722           15536 :     int min_count = 4;         /* min repeat count */
     723                 : 
     724           15536 :     if (nextlen == 0) max_count = 138, min_count = 3;
     725           15536 :     tree[max_code+1].Len = (ush)0xffff; /* guard */
     726                 : 
     727         2450017 :     for (n = 0; n <= max_code; n++) {
     728         2434481 :         curlen = nextlen; nextlen = tree[n+1].Len;
     729         2434481 :         if (++count < max_count && curlen == nextlen) {
     730         1055823 :             continue;
     731         1378658 :         } else if (count < min_count) {
     732         1233915 :             s->bl_tree[curlen].Freq += count;
     733          144743 :         } else if (curlen != 0) {
     734          117185 :             if (curlen != prevlen) s->bl_tree[curlen].Freq++;
     735          117185 :             s->bl_tree[REP_3_6].Freq++;
     736           27558 :         } else if (count <= 10) {
     737           23965 :             s->bl_tree[REPZ_3_10].Freq++;
     738                 :         } else {
     739            3593 :             s->bl_tree[REPZ_11_138].Freq++;
     740                 :         }
     741         1378658 :         count = 0; prevlen = curlen;
     742         1378658 :         if (nextlen == 0) {
     743          105648 :             max_count = 138, min_count = 3;
     744         1273010 :         } else if (curlen == nextlen) {
     745           23507 :             max_count = 6, min_count = 3;
     746                 :         } else {
     747         1249503 :             max_count = 7, min_count = 4;
     748                 :         }
     749                 :     }
     750           15536 : }
     751                 : 
     752                 : /* ===========================================================================
     753                 :  * Send a literal or distance tree in compressed form, using the codes in
     754                 :  * bl_tree.
     755                 :  */
     756           15472 : local void send_tree (s, tree, max_code)
     757                 :     deflate_state *s;
     758                 :     ct_data *tree; /* the tree to be scanned */
     759                 :     int max_code;       /* and its largest code of non zero frequency */
     760                 : {
     761                 :     int n;                     /* iterates over all tree elements */
     762           15472 :     int prevlen = -1;          /* last emitted length */
     763                 :     int curlen;                /* length of current code */
     764           15472 :     int nextlen = tree[0].Len; /* length of next code */
     765           15472 :     int count = 0;             /* repeat count of the current code */
     766           15472 :     int max_count = 7;         /* max repeat count */
     767           15472 :     int min_count = 4;         /* min repeat count */
     768                 : 
     769                 :     /* tree[max_code+1].Len = -1; */  /* guard already set */
     770           15472 :     if (nextlen == 0) max_count = 138, min_count = 3;
     771                 : 
     772         2441238 :     for (n = 0; n <= max_code; n++) {
     773         2425766 :         curlen = nextlen; nextlen = tree[n+1].Len;
     774         2425766 :         if (++count < max_count && curlen == nextlen) {
     775         1047732 :             continue;
     776         1378034 :         } else if (count < min_count) {
     777         1641609 :             do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
     778                 : 
     779          144587 :         } else if (curlen != 0) {
     780          117182 :             if (curlen != prevlen) {
     781          103315 :                 send_code(s, curlen, s->bl_tree); count--;
     782                 :             }
     783                 :             Assert(count >= 3 && count <= 6, " 3_6?");
     784          117182 :             send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
     785                 : 
     786           27405 :         } else if (count <= 10) {
     787           23891 :             send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
     788                 : 
     789                 :         } else {
     790            3514 :             send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
     791                 :         }
     792         1378034 :         count = 0; prevlen = curlen;
     793         1378034 :         if (nextlen == 0) {
     794          105413 :             max_count = 138, min_count = 3;
     795         1272621 :         } else if (curlen == nextlen) {
     796           23507 :             max_count = 6, min_count = 3;
     797                 :         } else {
     798         1249114 :             max_count = 7, min_count = 4;
     799                 :         }
     800                 :     }
     801           15472 : }
     802                 : 
     803                 : /* ===========================================================================
     804                 :  * Construct the Huffman tree for the bit lengths and return the index in
     805                 :  * bl_order of the last bit length code to send.
     806                 :  */
     807            7768 : local int build_bl_tree(s)
     808                 :     deflate_state *s;
     809                 : {
     810                 :     int max_blindex;  /* index of last bit length code of non zero freq */
     811                 : 
     812                 :     /* Determine the bit length frequencies for literal and distance trees */
     813            7768 :     scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
     814            7768 :     scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
     815                 : 
     816                 :     /* Build the bit length tree: */
     817            7768 :     build_tree(s, (tree_desc *)(&(s->bl_desc)));
     818                 :     /* opt_len now includes the length of the tree representations, except
     819                 :      * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
     820                 :      */
     821                 : 
     822                 :     /* Determine the number of bit length codes to send. The pkzip format
     823                 :      * requires that at least 4 bit length codes be sent. (appnote.txt says
     824                 :      * 3 but the actual value used is 4.)
     825                 :      */
     826           37349 :     for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
     827           37349 :         if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
     828                 :     }
     829                 :     /* Update opt_len to include the bit length tree and counts */
     830            7768 :     s->opt_len += 3*(max_blindex+1) + 5+5+4;
     831                 :     Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
     832                 :             s->opt_len, s->static_len));
     833                 : 
     834            7768 :     return max_blindex;
     835                 : }
     836                 : 
     837                 : /* ===========================================================================
     838                 :  * Send the header for a block using dynamic Huffman trees: the counts, the
     839                 :  * lengths of the bit length codes, the literal tree and the distance tree.
     840                 :  * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
     841                 :  */
     842            7736 : local void send_all_trees(s, lcodes, dcodes, blcodes)
     843                 :     deflate_state *s;
     844                 :     int lcodes, dcodes, blcodes; /* number of codes for each tree */
     845                 : {
     846                 :     int rank;                    /* index in bl_order */
     847                 : 
     848                 :     Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
     849                 :     Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
     850                 :             "too many codes");
     851                 :     Tracev((stderr, "\nbl counts: "));
     852            7736 :     send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
     853            7736 :     send_bits(s, dcodes-1,   5);
     854            7736 :     send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
     855          125175 :     for (rank = 0; rank < blcodes; rank++) {
     856                 :         Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
     857          117439 :         send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
     858                 :     }
     859                 :     Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
     860                 : 
     861            7736 :     send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
     862                 :     Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
     863                 : 
     864            7736 :     send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
     865                 :     Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
     866            7736 : }
     867                 : 
     868                 : /* ===========================================================================
     869                 :  * Send a stored block
     870                 :  */
     871               0 : void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
     872                 :     deflate_state *s;
     873                 :     charf *buf;       /* input block */
     874                 :     ulg stored_len;   /* length of input block */
     875                 :     int last;         /* one if this is the last block for a file */
     876                 : {
     877               0 :     send_bits(s, (STORED_BLOCK<<1)+last, 3);    /* send block type */
     878                 : #ifdef DEBUG
     879                 :     s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
     880                 :     s->compressed_len += (stored_len + 4) << 3;
     881                 : #endif
     882               0 :     copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
     883               0 : }
     884                 : 
     885                 : /* ===========================================================================
     886                 :  * Send one empty static block to give enough lookahead for inflate.
     887                 :  * This takes 10 bits, of which 7 may remain in the bit buffer.
     888                 :  * The current inflate code requires 9 bits of lookahead. If the
     889                 :  * last two codes for the previous block (real code plus EOB) were coded
     890                 :  * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
     891                 :  * the last real code. In this case we send two empty static blocks instead
     892                 :  * of one. (There are no problems if the previous block is stored or fixed.)
     893                 :  * To simplify the code, we assume the worst case of last real code encoded
     894                 :  * on one bit only.
     895                 :  */
     896               0 : void ZLIB_INTERNAL _tr_align(s)
     897                 :     deflate_state *s;
     898                 : {
     899               0 :     send_bits(s, STATIC_TREES<<1, 3);
     900               0 :     send_code(s, END_BLOCK, static_ltree);
     901                 : #ifdef DEBUG
     902                 :     s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
     903                 : #endif
     904               0 :     bi_flush(s);
     905                 :     /* Of the 10 bits for the empty block, we have already sent
     906                 :      * (10 - bi_valid) bits. The lookahead for the last real code (before
     907                 :      * the EOB of the previous block) was thus at least one plus the length
     908                 :      * of the EOB plus what we have just sent of the empty static block.
     909                 :      */
     910               0 :     if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
     911               0 :         send_bits(s, STATIC_TREES<<1, 3);
     912               0 :         send_code(s, END_BLOCK, static_ltree);
     913                 : #ifdef DEBUG
     914                 :         s->compressed_len += 10L;
     915                 : #endif
     916               0 :         bi_flush(s);
     917                 :     }
     918               0 :     s->last_eob_len = 7;
     919               0 : }
     920                 : 
     921                 : /* ===========================================================================
     922                 :  * Determine the best encoding for the current block: dynamic trees, static
     923                 :  * trees or store, and output the encoded block to the zip file.
     924                 :  */
     925            7768 : void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
     926                 :     deflate_state *s;
     927                 :     charf *buf;       /* input block, or NULL if too old */
     928                 :     ulg stored_len;   /* length of input block */
     929                 :     int last;         /* one if this is the last block for a file */
     930                 : {
     931                 :     ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
     932            7768 :     int max_blindex = 0;  /* index of last bit length code of non zero freq */
     933                 : 
     934                 :     /* Build the Huffman trees unless a stored block is forced */
     935            7768 :     if (s->level > 0) {
     936                 : 
     937                 :         /* Check if the file is binary or text */
     938            7768 :         if (s->strm->data_type == Z_UNKNOWN)
     939            5178 :             s->strm->data_type = detect_data_type(s);
     940                 : 
     941                 :         /* Construct the literal and distance trees */
     942            7768 :         build_tree(s, (tree_desc *)(&(s->l_desc)));
     943                 :         Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
     944                 :                 s->static_len));
     945                 : 
     946            7768 :         build_tree(s, (tree_desc *)(&(s->d_desc)));
     947                 :         Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
     948                 :                 s->static_len));
     949                 :         /* At this point, opt_len and static_len are the total bit lengths of
     950                 :          * the compressed block data, excluding the tree representations.
     951                 :          */
     952                 : 
     953                 :         /* Build the bit length tree for the above two trees, and get the index
     954                 :          * in bl_order of the last bit length code to send.
     955                 :          */
     956            7768 :         max_blindex = build_bl_tree(s);
     957                 : 
     958                 :         /* Determine the best encoding. Compute the block lengths in bytes. */
     959            7768 :         opt_lenb = (s->opt_len+3+7)>>3;
     960            7768 :         static_lenb = (s->static_len+3+7)>>3;
     961                 : 
     962                 :         Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
     963                 :                 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
     964                 :                 s->last_lit));
     965                 : 
     966            7768 :         if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
     967                 : 
     968                 :     } else {
     969                 :         Assert(buf != (char*)0, "lost buf");
     970               0 :         opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
     971                 :     }
     972                 : 
     973                 : #ifdef FORCE_STORED
     974                 :     if (buf != (char*)0) { /* force stored block */
     975                 : #else
     976            7768 :     if (stored_len+4 <= opt_lenb && buf != (char*)0) {
     977                 :                        /* 4: two words for the lengths */
     978                 : #endif
     979                 :         /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
     980                 :          * Otherwise we can't have processed more than WSIZE input bytes since
     981                 :          * the last block flush, because compression would have been
     982                 :          * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
     983                 :          * transform a block into a stored block.
     984                 :          */
     985               0 :         _tr_stored_block(s, buf, stored_len, last);
     986                 : 
     987                 : #ifdef FORCE_STATIC
     988                 :     } else if (static_lenb >= 0) { /* force static trees */
     989                 : #else
     990            7768 :     } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
     991                 : #endif
     992              32 :         send_bits(s, (STATIC_TREES<<1)+last, 3);
     993              32 :         compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
     994                 : #ifdef DEBUG
     995                 :         s->compressed_len += 3 + s->static_len;
     996                 : #endif
     997                 :     } else {
     998            7736 :         send_bits(s, (DYN_TREES<<1)+last, 3);
     999            7736 :         send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
    1000                 :                        max_blindex+1);
    1001            7736 :         compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
    1002                 : #ifdef DEBUG
    1003                 :         s->compressed_len += 3 + s->opt_len;
    1004                 : #endif
    1005                 :     }
    1006                 :     Assert (s->compressed_len == s->bits_sent, "bad compressed size");
    1007                 :     /* The above check is made mod 2^32, for files larger than 512 MB
    1008                 :      * and uLong implemented on 32 bits.
    1009                 :      */
    1010            7768 :     init_block(s);
    1011                 : 
    1012            7768 :     if (last) {
    1013            5191 :         bi_windup(s);
    1014                 : #ifdef DEBUG
    1015                 :         s->compressed_len += 7;  /* align on byte boundary */
    1016                 : #endif
    1017                 :     }
    1018                 :     Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
    1019                 :            s->compressed_len-7*last));
    1020            7768 : }
    1021                 : 
    1022                 : /* ===========================================================================
    1023                 :  * Save the match info and tally the frequency counts. Return true if
    1024                 :  * the current block must be flushed.
    1025                 :  */
    1026               0 : int ZLIB_INTERNAL _tr_tally (s, dist, lc)
    1027                 :     deflate_state *s;
    1028                 :     unsigned dist;  /* distance of matched string */
    1029                 :     unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
    1030                 : {
    1031               0 :     s->d_buf[s->last_lit] = (ush)dist;
    1032               0 :     s->l_buf[s->last_lit++] = (uch)lc;
    1033               0 :     if (dist == 0) {
    1034                 :         /* lc is the unmatched char */
    1035               0 :         s->dyn_ltree[lc].Freq++;
    1036                 :     } else {
    1037               0 :         s->matches++;
    1038                 :         /* Here, lc is the match length - MIN_MATCH */
    1039               0 :         dist--;             /* dist = match distance - 1 */
    1040                 :         Assert((ush)dist < (ush)MAX_DIST(s) &&
    1041                 :                (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
    1042                 :                (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");
    1043                 : 
    1044               0 :         s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
    1045               0 :         s->dyn_dtree[d_code(dist)].Freq++;
    1046                 :     }
    1047                 : 
    1048                 : #ifdef TRUNCATE_BLOCK
    1049                 :     /* Try to guess if it is profitable to stop the current block here */
    1050                 :     if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
    1051                 :         /* Compute an upper bound for the compressed length */
    1052                 :         ulg out_length = (ulg)s->last_lit*8L;
    1053                 :         ulg in_length = (ulg)((long)s->strstart - s->block_start);
    1054                 :         int dcode;
    1055                 :         for (dcode = 0; dcode < D_CODES; dcode++) {
    1056                 :             out_length += (ulg)s->dyn_dtree[dcode].Freq *
    1057                 :                 (5L+extra_dbits[dcode]);
    1058                 :         }
    1059                 :         out_length >>= 3;
    1060                 :         Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
    1061                 :                s->last_lit, in_length, out_length,
    1062                 :                100L - out_length*100L/in_length));
    1063                 :         if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
    1064                 :     }
    1065                 : #endif
    1066               0 :     return (s->last_lit == s->lit_bufsize-1);
    1067                 :     /* We avoid equality with lit_bufsize because of wraparound at 64K
    1068                 :      * on 16 bit machines and because stored blocks are restricted to
    1069                 :      * 64K-1 bytes.
    1070                 :      */
    1071                 : }
    1072                 : 
    1073                 : /* ===========================================================================
    1074                 :  * Send the block data compressed using the given Huffman trees
    1075                 :  */
    1076            7768 : local void compress_block(s, ltree, dtree)
    1077                 :     deflate_state *s;
    1078                 :     ct_data *ltree; /* literal tree */
    1079                 :     ct_data *dtree; /* distance tree */
    1080                 : {
    1081                 :     unsigned dist;      /* distance of matched string */
    1082                 :     int lc;             /* match length or unmatched char (if dist == 0) */
    1083            7768 :     unsigned lx = 0;    /* running index in l_buf */
    1084                 :     unsigned code;      /* the code to send */
    1085                 :     int extra;          /* number of extra bits to send */
    1086                 : 
    1087            7768 :     if (s->last_lit != 0) do {
    1088        69755658 :         dist = s->d_buf[lx];
    1089        69755658 :         lc = s->l_buf[lx++];
    1090        69755658 :         if (dist == 0) {
    1091        22855595 :             send_code(s, lc, ltree); /* send a literal byte */
    1092                 :             Tracecv(isgraph(lc), (stderr," '%c' ", lc));
    1093                 :         } else {
    1094                 :             /* Here, lc is the match length - MIN_MATCH */
    1095        46900063 :             code = _length_code[lc];
    1096        46900063 :             send_code(s, code+LITERALS+1, ltree); /* send the length code */
    1097        46900063 :             extra = extra_lbits[code];
    1098        46900063 :             if (extra != 0) {
    1099        14887972 :                 lc -= base_length[code];
    1100        14887972 :                 send_bits(s, lc, extra);       /* send the extra length bits */
    1101                 :             }
    1102        46900063 :             dist--; /* dist is now the match distance - 1 */
    1103        46900063 :             code = d_code(dist);
    1104                 :             Assert (code < D_CODES, "bad d_code");
    1105                 : 
    1106        46900063 :             send_code(s, code, dtree);       /* send the distance code */
    1107        46900063 :             extra = extra_dbits[code];
    1108        46900063 :             if (extra != 0) {
    1109        45935192 :                 dist -= base_dist[code];
    1110        45935192 :                 send_bits(s, dist, extra);   /* send the extra distance bits */
    1111                 :             }
    1112                 :         } /* literal or match pair ? */
    1113                 : 
    1114                 :         /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
    1115                 :         Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
    1116                 :                "pendingBuf overflow");
    1117                 : 
    1118        69755658 :     } while (lx < s->last_lit);
    1119                 : 
    1120            7768 :     send_code(s, END_BLOCK, ltree);
    1121            7768 :     s->last_eob_len = ltree[END_BLOCK].Len;
    1122            7768 : }
    1123                 : 
    1124                 : /* ===========================================================================
    1125                 :  * Check if the data type is TEXT or BINARY, using the following algorithm:
    1126                 :  * - TEXT if the two conditions below are satisfied:
    1127                 :  *    a) There are no non-portable control characters belonging to the
    1128                 :  *       "black list" (0..6, 14..25, 28..31).
    1129                 :  *    b) There is at least one printable character belonging to the
    1130                 :  *       "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
    1131                 :  * - BINARY otherwise.
    1132                 :  * - The following partially-portable control characters form a
    1133                 :  *   "gray list" that is ignored in this detection algorithm:
    1134                 :  *   (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
    1135                 :  * IN assertion: the fields Freq of dyn_ltree are set.
    1136                 :  */
    1137            5178 : local int detect_data_type(s)
    1138                 :     deflate_state *s;
    1139                 : {
    1140                 :     /* black_mask is the bit mask of black-listed bytes
    1141                 :      * set bits 0..6, 14..25, and 28..31
    1142                 :      * 0xf3ffc07f = binary 11110011111111111100000001111111
    1143                 :      */
    1144            5178 :     unsigned long black_mask = 0xf3ffc07fUL;
    1145                 :     int n;
    1146                 : 
    1147                 :     /* Check for non-textual ("black-listed") bytes. */
    1148            5466 :     for (n = 0; n <= 31; n++, black_mask >>= 1)
    1149            5457 :         if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
    1150            5169 :             return Z_BINARY;
    1151                 : 
    1152                 :     /* Check for textual ("white-listed") bytes. */
    1153               9 :     if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
    1154               7 :             || s->dyn_ltree[13].Freq != 0)
    1155               2 :         return Z_TEXT;
    1156             463 :     for (n = 32; n < LITERALS; n++)
    1157             461 :         if (s->dyn_ltree[n].Freq != 0)
    1158               5 :             return Z_TEXT;
    1159                 : 
    1160                 :     /* There are no "black-listed" or "white-listed" bytes:
    1161                 :      * this stream either is empty or has tolerated ("gray-listed") bytes only.
    1162                 :      */
    1163               2 :     return Z_BINARY;
    1164                 : }
    1165                 : 
    1166                 : /* ===========================================================================
    1167                 :  * Reverse the first len bits of a code, using straightforward code (a faster
    1168                 :  * method would use a table)
    1169                 :  * IN assertion: 1 <= len <= 15
    1170                 :  */
    1171         2254882 : local unsigned bi_reverse(code, len)
    1172                 :     unsigned code; /* the value to invert */
    1173                 :     int len;       /* its bit length */
    1174                 : {
    1175         2254882 :     register unsigned res = 0;
    1176                 :     do {
    1177        20372186 :         res |= code & 1;
    1178        20372186 :         code >>= 1, res <<= 1;
    1179        20372186 :     } while (--len > 0);
    1180         2254882 :     return res >> 1;
    1181                 : }
    1182                 : 
    1183                 : /* ===========================================================================
    1184                 :  * Flush the bit buffer, keeping at most 7 bits in it.
    1185                 :  */
    1186               0 : local void bi_flush(s)
    1187                 :     deflate_state *s;
    1188                 : {
    1189               0 :     if (s->bi_valid == 16) {
    1190               0 :         put_short(s, s->bi_buf);
    1191               0 :         s->bi_buf = 0;
    1192               0 :         s->bi_valid = 0;
    1193               0 :     } else if (s->bi_valid >= 8) {
    1194               0 :         put_byte(s, (Byte)s->bi_buf);
    1195               0 :         s->bi_buf >>= 8;
    1196               0 :         s->bi_valid -= 8;
    1197                 :     }
    1198               0 : }
    1199                 : 
    1200                 : /* ===========================================================================
    1201                 :  * Flush the bit buffer and align the output on a byte boundary
    1202                 :  */
    1203            5191 : local void bi_windup(s)
    1204                 :     deflate_state *s;
    1205                 : {
    1206            5191 :     if (s->bi_valid > 8) {
    1207            3200 :         put_short(s, s->bi_buf);
    1208            1991 :     } else if (s->bi_valid > 0) {
    1209            1991 :         put_byte(s, (Byte)s->bi_buf);
    1210                 :     }
    1211            5191 :     s->bi_buf = 0;
    1212            5191 :     s->bi_valid = 0;
    1213                 : #ifdef DEBUG
    1214                 :     s->bits_sent = (s->bits_sent+7) & ~7;
    1215                 : #endif
    1216            5191 : }
    1217                 : 
    1218                 : /* ===========================================================================
    1219                 :  * Copy a stored block, storing first the length and its
    1220                 :  * one's complement if requested.
    1221                 :  */
    1222               0 : local void copy_block(s, buf, len, header)
    1223                 :     deflate_state *s;
    1224                 :     charf    *buf;    /* the input data */
    1225                 :     unsigned len;     /* its length */
    1226                 :     int      header;  /* true if block header must be written */
    1227                 : {
    1228               0 :     bi_windup(s);        /* align on byte boundary */
    1229               0 :     s->last_eob_len = 8; /* enough lookahead for inflate */
    1230                 : 
    1231               0 :     if (header) {
    1232               0 :         put_short(s, (ush)len);
    1233               0 :         put_short(s, (ush)~len);
    1234                 : #ifdef DEBUG
    1235                 :         s->bits_sent += 2*16;
    1236                 : #endif
    1237                 :     }
    1238                 : #ifdef DEBUG
    1239                 :     s->bits_sent += (ulg)len<<3;
    1240                 : #endif
    1241               0 :     while (len--) {
    1242               0 :         put_byte(s, *buf++);
    1243                 :     }
    1244               0 : }

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