1 /* +++ trees.c */ 1 /* +++ trees.c */
2 /* trees.c -- output deflated data using Huffm 2 /* trees.c -- output deflated data using Huffman coding
3 * Copyright (C) 1995-1996 Jean-loup Gailly 3 * Copyright (C) 1995-1996 Jean-loup Gailly
4 * For conditions of distribution and use, see 4 * For conditions of distribution and use, see copyright notice in zlib.h
5 */ 5 */
6 6
7 /* 7 /*
8 * ALGORITHM 8 * ALGORITHM
9 * 9 *
10 * The "deflation" process uses several H 10 * The "deflation" process uses several Huffman trees. The more
11 * common source values are represented b 11 * common source values are represented by shorter bit sequences.
12 * 12 *
13 * Each code tree is stored in a compress 13 * Each code tree is stored in a compressed form which is itself
14 * a Huffman encoding of the lengths of all th 14 * a Huffman encoding of the lengths of all the code strings (in
15 * ascending order by source values). The act 15 * ascending order by source values). The actual code strings are
16 * reconstructed from the lengths in the infla 16 * reconstructed from the lengths in the inflate process, as described
17 * in the deflate specification. 17 * in the deflate specification.
18 * 18 *
19 * REFERENCES 19 * REFERENCES
20 * 20 *
21 * Deutsch, L.P.,"'Deflate' Compressed Da 21 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
22 * Available in ftp.uu.net:/pub/archiving 22 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
23 * 23 *
24 * Storer, James A. 24 * Storer, James A.
25 * Data Compression: Methods and The 25 * Data Compression: Methods and Theory, pp. 49-50.
26 * Computer Science Press, 1988. ISB 26 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
27 * 27 *
28 * Sedgewick, R. 28 * Sedgewick, R.
29 * Algorithms, p290. 29 * Algorithms, p290.
30 * Addison-Wesley, 1983. ISBN 0-201-0 30 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
31 */ 31 */
32 32
33 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me 33 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
34 34
35 /* #include "deflate.h" */ 35 /* #include "deflate.h" */
36 36
37 #include <linux/zutil.h> 37 #include <linux/zutil.h>
38 #include <linux/bitrev.h> 38 #include <linux/bitrev.h>
39 #include "defutil.h" 39 #include "defutil.h"
40 40
41 #ifdef DEBUG_ZLIB 41 #ifdef DEBUG_ZLIB
42 # include <ctype.h> 42 # include <ctype.h>
43 #endif 43 #endif
44 44
45 /* =========================================== 45 /* ===========================================================================
46 * Constants 46 * Constants
47 */ 47 */
48 48
49 #define MAX_BL_BITS 7 49 #define MAX_BL_BITS 7
50 /* Bit length codes must not exceed MAX_BL_BIT 50 /* Bit length codes must not exceed MAX_BL_BITS bits */
51 51
52 #define END_BLOCK 256 52 #define END_BLOCK 256
53 /* end of block literal code */ 53 /* end of block literal code */
54 54
55 #define REP_3_6 16 55 #define REP_3_6 16
56 /* repeat previous bit length 3-6 times (2 bit 56 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
57 57
58 #define REPZ_3_10 17 58 #define REPZ_3_10 17
59 /* repeat a zero length 3-10 times (3 bits of 59 /* repeat a zero length 3-10 times (3 bits of repeat count) */
60 60
61 #define REPZ_11_138 18 61 #define REPZ_11_138 18
62 /* repeat a zero length 11-138 times (7 bits 62 /* repeat a zero length 11-138 times (7 bits of repeat count) */
63 63
64 static const int extra_lbits[LENGTH_CODES] /* 64 static const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
65 = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3, 65 = {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};
66 66
67 static const int extra_dbits[D_CODES] /* extra 67 static const int extra_dbits[D_CODES] /* extra bits for each distance code */
68 = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8, 68 = {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};
69 69
70 static const int extra_blbits[BL_CODES]/* extr 70 static const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
71 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 71 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
72 72
73 static const uch bl_order[BL_CODES] 73 static const uch bl_order[BL_CODES]
74 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,1 74 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
75 /* The lengths of the bit length codes are sen 75 /* The lengths of the bit length codes are sent in order of decreasing
76 * probability, to avoid transmitting the leng 76 * probability, to avoid transmitting the lengths for unused bit length codes.
77 */ 77 */
78 78
>> 79 #define Buf_size (8 * 2*sizeof(char))
>> 80 /* Number of bits used within bi_buf. (bi_buf might be implemented on
>> 81 * more than 16 bits on some systems.)
>> 82 */
>> 83
79 /* =========================================== 84 /* ===========================================================================
80 * Local data. These are initialized only once 85 * Local data. These are initialized only once.
81 */ 86 */
82 87
83 static ct_data static_ltree[L_CODES+2]; 88 static ct_data static_ltree[L_CODES+2];
84 /* The static literal tree. Since the bit leng 89 /* The static literal tree. Since the bit lengths are imposed, there is no
85 * need for the L_CODES extra codes used durin 90 * need for the L_CODES extra codes used during heap construction. However
86 * The codes 286 and 287 are needed to build a 91 * The codes 286 and 287 are needed to build a canonical tree (see zlib_tr_init
87 * below). 92 * below).
88 */ 93 */
89 94
90 static ct_data static_dtree[D_CODES]; 95 static ct_data static_dtree[D_CODES];
91 /* The static distance tree. (Actually a trivi 96 /* The static distance tree. (Actually a trivial tree since all codes use
92 * 5 bits.) 97 * 5 bits.)
93 */ 98 */
94 99
95 static uch dist_code[512]; 100 static uch dist_code[512];
96 /* distance codes. The first 256 values corres 101 /* distance codes. The first 256 values correspond to the distances
97 * 3 .. 258, the last 256 values correspond to 102 * 3 .. 258, the last 256 values correspond to the top 8 bits of
98 * the 15 bit distances. 103 * the 15 bit distances.
99 */ 104 */
100 105
101 static uch length_code[MAX_MATCH-MIN_MATCH+1]; 106 static uch length_code[MAX_MATCH-MIN_MATCH+1];
102 /* length code for each normalized match lengt 107 /* length code for each normalized match length (0 == MIN_MATCH) */
103 108
104 static int base_length[LENGTH_CODES]; 109 static int base_length[LENGTH_CODES];
105 /* First normalized length for each code (0 = 110 /* First normalized length for each code (0 = MIN_MATCH) */
106 111
107 static int base_dist[D_CODES]; 112 static int base_dist[D_CODES];
108 /* First normalized distance for each code (0 113 /* First normalized distance for each code (0 = distance of 1) */
109 114
110 struct static_tree_desc_s { 115 struct static_tree_desc_s {
111 const ct_data *static_tree; /* static tre 116 const ct_data *static_tree; /* static tree or NULL */
112 const int *extra_bits; /* extra bits 117 const int *extra_bits; /* extra bits for each code or NULL */
113 int extra_base; /* base index 118 int extra_base; /* base index for extra_bits */
114 int elems; /* max number 119 int elems; /* max number of elements in the tree */
115 int max_length; /* max bit le 120 int max_length; /* max bit length for the codes */
116 }; 121 };
117 122
118 static static_tree_desc static_l_desc = 123 static static_tree_desc static_l_desc =
119 {static_ltree, extra_lbits, LITERALS+1, L_CODE 124 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
120 125
121 static static_tree_desc static_d_desc = 126 static static_tree_desc static_d_desc =
122 {static_dtree, extra_dbits, 0, D_CODE 127 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
123 128
124 static static_tree_desc static_bl_desc = 129 static static_tree_desc static_bl_desc =
125 {(const ct_data *)0, extra_blbits, 0, BL_COD 130 {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
126 131
127 /* =========================================== 132 /* ===========================================================================
128 * Local (static) routines in this file. 133 * Local (static) routines in this file.
129 */ 134 */
130 135
131 static void tr_static_init (void); 136 static void tr_static_init (void);
132 static void init_block (deflate_state *s); 137 static void init_block (deflate_state *s);
133 static void pqdownheap (deflate_state *s, 138 static void pqdownheap (deflate_state *s, ct_data *tree, int k);
134 static void gen_bitlen (deflate_state *s, 139 static void gen_bitlen (deflate_state *s, tree_desc *desc);
135 static void gen_codes (ct_data *tree, int 140 static void gen_codes (ct_data *tree, int max_code, ush *bl_count);
136 static void build_tree (deflate_state *s, 141 static void build_tree (deflate_state *s, tree_desc *desc);
137 static void scan_tree (deflate_state *s, 142 static void scan_tree (deflate_state *s, ct_data *tree, int max_code);
138 static void send_tree (deflate_state *s, 143 static void send_tree (deflate_state *s, ct_data *tree, int max_code);
139 static int build_bl_tree (deflate_state *s); 144 static int build_bl_tree (deflate_state *s);
140 static void send_all_trees (deflate_state *s, 145 static void send_all_trees (deflate_state *s, int lcodes, int dcodes,
141 int blcodes); 146 int blcodes);
142 static void compress_block (deflate_state *s, 147 static void compress_block (deflate_state *s, ct_data *ltree,
143 ct_data *dtree); 148 ct_data *dtree);
144 static void set_data_type (deflate_state *s); 149 static void set_data_type (deflate_state *s);
>> 150 static void bi_windup (deflate_state *s);
145 static void bi_flush (deflate_state *s); 151 static void bi_flush (deflate_state *s);
146 static void copy_block (deflate_state *s, 152 static void copy_block (deflate_state *s, char *buf, unsigned len,
147 int header); 153 int header);
148 154
149 #ifndef DEBUG_ZLIB 155 #ifndef DEBUG_ZLIB
150 # define send_code(s, c, tree) send_bits(s, t 156 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
151 /* Send a code of the given tree. c and tre 157 /* Send a code of the given tree. c and tree must not have side effects */
152 158
153 #else /* DEBUG_ZLIB */ 159 #else /* DEBUG_ZLIB */
154 # define send_code(s, c, tree) \ 160 # define send_code(s, c, tree) \
155 { if (z_verbose>2) fprintf(stderr,"\ncd % 161 { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
156 send_bits(s, tree[c].Code, tree[c].Len) 162 send_bits(s, tree[c].Code, tree[c].Len); }
157 #endif 163 #endif
158 164
159 #define d_code(dist) \ 165 #define d_code(dist) \
160 ((dist) < 256 ? dist_code[dist] : dist_code 166 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
161 /* Mapping from a distance to a distance code. 167 /* Mapping from a distance to a distance code. dist is the distance - 1 and
162 * must not have side effects. dist_code[256] 168 * must not have side effects. dist_code[256] and dist_code[257] are never
163 * used. 169 * used.
164 */ 170 */
>> 171
>> 172 /* ===========================================================================
>> 173 * Send a value on a given number of bits.
>> 174 * IN assertion: length <= 16 and value fits in length bits.
>> 175 */
>> 176 #ifdef DEBUG_ZLIB
>> 177 static void send_bits (deflate_state *s, int value, int length);
>> 178
>> 179 static void send_bits(
>> 180 deflate_state *s,
>> 181 int value, /* value to send */
>> 182 int length /* number of bits */
>> 183 )
>> 184 {
>> 185 Tracevv((stderr," l %2d v %4x ", length, value));
>> 186 Assert(length > 0 && length <= 15, "invalid length");
>> 187 s->bits_sent += (ulg)length;
>> 188
>> 189 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
>> 190 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
>> 191 * unused bits in value.
>> 192 */
>> 193 if (s->bi_valid > (int)Buf_size - length) {
>> 194 s->bi_buf |= (value << s->bi_valid);
>> 195 put_short(s, s->bi_buf);
>> 196 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
>> 197 s->bi_valid += length - Buf_size;
>> 198 } else {
>> 199 s->bi_buf |= value << s->bi_valid;
>> 200 s->bi_valid += length;
>> 201 }
>> 202 }
>> 203 #else /* !DEBUG_ZLIB */
>> 204
>> 205 #define send_bits(s, value, length) \
>> 206 { int len = length;\
>> 207 if (s->bi_valid > (int)Buf_size - len) {\
>> 208 int val = value;\
>> 209 s->bi_buf |= (val << s->bi_valid);\
>> 210 put_short(s, s->bi_buf);\
>> 211 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
>> 212 s->bi_valid += len - Buf_size;\
>> 213 } else {\
>> 214 s->bi_buf |= (value) << s->bi_valid;\
>> 215 s->bi_valid += len;\
>> 216 }\
>> 217 }
>> 218 #endif /* DEBUG_ZLIB */
165 219
166 /* =========================================== 220 /* ===========================================================================
167 * Initialize the various 'constant' tables. I 221 * Initialize the various 'constant' tables. In a multi-threaded environment,
168 * this function may be called by two threads 222 * this function may be called by two threads concurrently, but this is
169 * harmless since both invocations do exactly 223 * harmless since both invocations do exactly the same thing.
170 */ 224 */
171 static void tr_static_init(void) 225 static void tr_static_init(void)
172 { 226 {
173 static int static_init_done; 227 static int static_init_done;
174 int n; /* iterates over tree elemen 228 int n; /* iterates over tree elements */
175 int bits; /* bit counter */ 229 int bits; /* bit counter */
176 int length; /* length value */ 230 int length; /* length value */
177 int code; /* code value */ 231 int code; /* code value */
178 int dist; /* distance index */ 232 int dist; /* distance index */
179 ush bl_count[MAX_BITS+1]; 233 ush bl_count[MAX_BITS+1];
180 /* number of codes at each bit length for 234 /* number of codes at each bit length for an optimal tree */
181 235
182 if (static_init_done) return; 236 if (static_init_done) return;
183 237
184 /* Initialize the mapping length (0..255) 238 /* Initialize the mapping length (0..255) -> length code (0..28) */
185 length = 0; 239 length = 0;
186 for (code = 0; code < LENGTH_CODES-1; code 240 for (code = 0; code < LENGTH_CODES-1; code++) {
187 base_length[code] = length; 241 base_length[code] = length;
188 for (n = 0; n < (1<<extra_lbits[code]) 242 for (n = 0; n < (1<<extra_lbits[code]); n++) {
189 length_code[length++] = (uch)code; 243 length_code[length++] = (uch)code;
190 } 244 }
191 } 245 }
192 Assert (length == 256, "tr_static_init: le 246 Assert (length == 256, "tr_static_init: length != 256");
193 /* Note that the length 255 (match length 247 /* Note that the length 255 (match length 258) can be represented
194 * in two different ways: code 284 + 5 bit 248 * in two different ways: code 284 + 5 bits or code 285, so we
195 * overwrite length_code[255] to use the b 249 * overwrite length_code[255] to use the best encoding:
196 */ 250 */
197 length_code[length-1] = (uch)code; 251 length_code[length-1] = (uch)code;
198 252
199 /* Initialize the mapping dist (0..32K) -> 253 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
200 dist = 0; 254 dist = 0;
201 for (code = 0 ; code < 16; code++) { 255 for (code = 0 ; code < 16; code++) {
202 base_dist[code] = dist; 256 base_dist[code] = dist;
203 for (n = 0; n < (1<<extra_dbits[code]) 257 for (n = 0; n < (1<<extra_dbits[code]); n++) {
204 dist_code[dist++] = (uch)code; 258 dist_code[dist++] = (uch)code;
205 } 259 }
206 } 260 }
207 Assert (dist == 256, "tr_static_init: dist 261 Assert (dist == 256, "tr_static_init: dist != 256");
208 dist >>= 7; /* from now on, all distances 262 dist >>= 7; /* from now on, all distances are divided by 128 */
209 for ( ; code < D_CODES; code++) { 263 for ( ; code < D_CODES; code++) {
210 base_dist[code] = dist << 7; 264 base_dist[code] = dist << 7;
211 for (n = 0; n < (1<<(extra_dbits[code] 265 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
212 dist_code[256 + dist++] = (uch)cod 266 dist_code[256 + dist++] = (uch)code;
213 } 267 }
214 } 268 }
215 Assert (dist == 256, "tr_static_init: 256+ 269 Assert (dist == 256, "tr_static_init: 256+dist != 512");
216 270
217 /* Construct the codes of the static liter 271 /* Construct the codes of the static literal tree */
218 for (bits = 0; bits <= MAX_BITS; bits++) b 272 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
219 n = 0; 273 n = 0;
220 while (n <= 143) static_ltree[n++].Len = 8 274 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
221 while (n <= 255) static_ltree[n++].Len = 9 275 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
222 while (n <= 279) static_ltree[n++].Len = 7 276 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
223 while (n <= 287) static_ltree[n++].Len = 8 277 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
224 /* Codes 286 and 287 do not exist, but we 278 /* Codes 286 and 287 do not exist, but we must include them in the
225 * tree construction to get a canonical Hu 279 * tree construction to get a canonical Huffman tree (longest code
226 * all ones) 280 * all ones)
227 */ 281 */
228 gen_codes((ct_data *)static_ltree, L_CODES 282 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
229 283
230 /* The static distance tree is trivial: */ 284 /* The static distance tree is trivial: */
231 for (n = 0; n < D_CODES; n++) { 285 for (n = 0; n < D_CODES; n++) {
232 static_dtree[n].Len = 5; 286 static_dtree[n].Len = 5;
233 static_dtree[n].Code = bitrev32((u32)n 287 static_dtree[n].Code = bitrev32((u32)n) >> (32 - 5);
234 } 288 }
235 static_init_done = 1; 289 static_init_done = 1;
236 } 290 }
237 291
238 /* =========================================== 292 /* ===========================================================================
239 * Initialize the tree data structures for a n 293 * Initialize the tree data structures for a new zlib stream.
240 */ 294 */
241 void zlib_tr_init( 295 void zlib_tr_init(
242 deflate_state *s 296 deflate_state *s
243 ) 297 )
244 { 298 {
245 tr_static_init(); 299 tr_static_init();
246 300
247 s->compressed_len = 0L; 301 s->compressed_len = 0L;
248 302
249 s->l_desc.dyn_tree = s->dyn_ltree; 303 s->l_desc.dyn_tree = s->dyn_ltree;
250 s->l_desc.stat_desc = &static_l_desc; 304 s->l_desc.stat_desc = &static_l_desc;
251 305
252 s->d_desc.dyn_tree = s->dyn_dtree; 306 s->d_desc.dyn_tree = s->dyn_dtree;
253 s->d_desc.stat_desc = &static_d_desc; 307 s->d_desc.stat_desc = &static_d_desc;
254 308
255 s->bl_desc.dyn_tree = s->bl_tree; 309 s->bl_desc.dyn_tree = s->bl_tree;
256 s->bl_desc.stat_desc = &static_bl_desc; 310 s->bl_desc.stat_desc = &static_bl_desc;
257 311
258 s->bi_buf = 0; 312 s->bi_buf = 0;
259 s->bi_valid = 0; 313 s->bi_valid = 0;
260 s->last_eob_len = 8; /* enough lookahead f 314 s->last_eob_len = 8; /* enough lookahead for inflate */
261 #ifdef DEBUG_ZLIB 315 #ifdef DEBUG_ZLIB
262 s->bits_sent = 0L; 316 s->bits_sent = 0L;
263 #endif 317 #endif
264 318
265 /* Initialize the first block of the first 319 /* Initialize the first block of the first file: */
266 init_block(s); 320 init_block(s);
267 } 321 }
268 322
269 /* =========================================== 323 /* ===========================================================================
270 * Initialize a new block. 324 * Initialize a new block.
271 */ 325 */
272 static void init_block( 326 static void init_block(
273 deflate_state *s 327 deflate_state *s
274 ) 328 )
275 { 329 {
276 int n; /* iterates over tree elements */ 330 int n; /* iterates over tree elements */
277 331
278 /* Initialize the trees. */ 332 /* Initialize the trees. */
279 for (n = 0; n < L_CODES; n++) s->dyn_ltre 333 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
280 for (n = 0; n < D_CODES; n++) s->dyn_dtre 334 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
281 for (n = 0; n < BL_CODES; n++) s->bl_tree[ 335 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
282 336
283 s->dyn_ltree[END_BLOCK].Freq = 1; 337 s->dyn_ltree[END_BLOCK].Freq = 1;
284 s->opt_len = s->static_len = 0L; 338 s->opt_len = s->static_len = 0L;
285 s->last_lit = s->matches = 0; 339 s->last_lit = s->matches = 0;
286 } 340 }
287 341
288 #define SMALLEST 1 342 #define SMALLEST 1
289 /* Index within the heap array of least freque 343 /* Index within the heap array of least frequent node in the Huffman tree */
290 344
291 345
292 /* =========================================== 346 /* ===========================================================================
293 * Remove the smallest element from the heap a 347 * Remove the smallest element from the heap and recreate the heap with
294 * one less element. Updates heap and heap_len 348 * one less element. Updates heap and heap_len.
295 */ 349 */
296 #define pqremove(s, tree, top) \ 350 #define pqremove(s, tree, top) \
297 {\ 351 {\
298 top = s->heap[SMALLEST]; \ 352 top = s->heap[SMALLEST]; \
299 s->heap[SMALLEST] = s->heap[s->heap_len--] 353 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
300 pqdownheap(s, tree, SMALLEST); \ 354 pqdownheap(s, tree, SMALLEST); \
301 } 355 }
302 356
303 /* =========================================== 357 /* ===========================================================================
304 * Compares to subtrees, using the tree depth 358 * Compares to subtrees, using the tree depth as tie breaker when
305 * the subtrees have equal frequency. This min 359 * the subtrees have equal frequency. This minimizes the worst case length.
306 */ 360 */
307 #define smaller(tree, n, m, depth) \ 361 #define smaller(tree, n, m, depth) \
308 (tree[n].Freq < tree[m].Freq || \ 362 (tree[n].Freq < tree[m].Freq || \
309 (tree[n].Freq == tree[m].Freq && depth[n] < 363 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
310 364
311 /* =========================================== 365 /* ===========================================================================
312 * Restore the heap property by moving down th 366 * Restore the heap property by moving down the tree starting at node k,
313 * exchanging a node with the smallest of its 367 * exchanging a node with the smallest of its two sons if necessary, stopping
314 * when the heap property is re-established (e 368 * when the heap property is re-established (each father smaller than its
315 * two sons). 369 * two sons).
316 */ 370 */
317 static void pqdownheap( 371 static void pqdownheap(
318 deflate_state *s, 372 deflate_state *s,
319 ct_data *tree, /* the tree to restore 373 ct_data *tree, /* the tree to restore */
320 int k /* node to move down * 374 int k /* node to move down */
321 ) 375 )
322 { 376 {
323 int v = s->heap[k]; 377 int v = s->heap[k];
324 int j = k << 1; /* left son of k */ 378 int j = k << 1; /* left son of k */
325 while (j <= s->heap_len) { 379 while (j <= s->heap_len) {
326 /* Set j to the smallest of the two so 380 /* Set j to the smallest of the two sons: */
327 if (j < s->heap_len && 381 if (j < s->heap_len &&
328 smaller(tree, s->heap[j+1], s->hea 382 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
329 j++; 383 j++;
330 } 384 }
331 /* Exit if v is smaller than both sons 385 /* Exit if v is smaller than both sons */
332 if (smaller(tree, v, s->heap[j], s->de 386 if (smaller(tree, v, s->heap[j], s->depth)) break;
333 387
334 /* Exchange v with the smallest son */ 388 /* Exchange v with the smallest son */
335 s->heap[k] = s->heap[j]; k = j; 389 s->heap[k] = s->heap[j]; k = j;
336 390
337 /* And continue down the tree, setting 391 /* And continue down the tree, setting j to the left son of k */
338 j <<= 1; 392 j <<= 1;
339 } 393 }
340 s->heap[k] = v; 394 s->heap[k] = v;
341 } 395 }
342 396
343 /* =========================================== 397 /* ===========================================================================
344 * Compute the optimal bit lengths for a tree 398 * Compute the optimal bit lengths for a tree and update the total bit length
345 * for the current block. 399 * for the current block.
346 * IN assertion: the fields freq and dad are s 400 * IN assertion: the fields freq and dad are set, heap[heap_max] and
347 * above are the tree nodes sorted by incre 401 * above are the tree nodes sorted by increasing frequency.
348 * OUT assertions: the field len is set to the 402 * OUT assertions: the field len is set to the optimal bit length, the
349 * array bl_count contains the frequencies 403 * array bl_count contains the frequencies for each bit length.
350 * The length opt_len is updated; static_l 404 * The length opt_len is updated; static_len is also updated if stree is
351 * not null. 405 * not null.
352 */ 406 */
353 static void gen_bitlen( 407 static void gen_bitlen(
354 deflate_state *s, 408 deflate_state *s,
355 tree_desc *desc /* the tree descrip 409 tree_desc *desc /* the tree descriptor */
356 ) 410 )
357 { 411 {
358 ct_data *tree = desc->dyn_tree; 412 ct_data *tree = desc->dyn_tree;
359 int max_code = desc->max_code; 413 int max_code = desc->max_code;
360 const ct_data *stree = desc->stat_desc->st 414 const ct_data *stree = desc->stat_desc->static_tree;
361 const int *extra = desc->stat_desc->ex 415 const int *extra = desc->stat_desc->extra_bits;
362 int base = desc->stat_desc->ex 416 int base = desc->stat_desc->extra_base;
363 int max_length = desc->stat_desc->ma 417 int max_length = desc->stat_desc->max_length;
364 int h; /* heap index */ 418 int h; /* heap index */
365 int n, m; /* iterate over the tr 419 int n, m; /* iterate over the tree elements */
366 int bits; /* bit length */ 420 int bits; /* bit length */
367 int xbits; /* extra bits */ 421 int xbits; /* extra bits */
368 ush f; /* frequency */ 422 ush f; /* frequency */
369 int overflow = 0; /* number of elements 423 int overflow = 0; /* number of elements with bit length too large */
370 424
371 for (bits = 0; bits <= MAX_BITS; bits++) s 425 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
372 426
373 /* In a first pass, compute the optimal bi 427 /* In a first pass, compute the optimal bit lengths (which may
374 * overflow in the case of the bit length 428 * overflow in the case of the bit length tree).
375 */ 429 */
376 tree[s->heap[s->heap_max]].Len = 0; /* roo 430 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
377 431
378 for (h = s->heap_max+1; h < HEAP_SIZE; h++ 432 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
379 n = s->heap[h]; 433 n = s->heap[h];
380 bits = tree[tree[n].Dad].Len + 1; 434 bits = tree[tree[n].Dad].Len + 1;
381 if (bits > max_length) bits = max_leng 435 if (bits > max_length) bits = max_length, overflow++;
382 tree[n].Len = (ush)bits; 436 tree[n].Len = (ush)bits;
383 /* We overwrite tree[n].Dad which is n 437 /* We overwrite tree[n].Dad which is no longer needed */
384 438
385 if (n > max_code) continue; /* not a l 439 if (n > max_code) continue; /* not a leaf node */
386 440
387 s->bl_count[bits]++; 441 s->bl_count[bits]++;
388 xbits = 0; 442 xbits = 0;
389 if (n >= base) xbits = extra[n-base]; 443 if (n >= base) xbits = extra[n-base];
390 f = tree[n].Freq; 444 f = tree[n].Freq;
391 s->opt_len += (ulg)f * (bits + xbits); 445 s->opt_len += (ulg)f * (bits + xbits);
392 if (stree) s->static_len += (ulg)f * ( 446 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
393 } 447 }
394 if (overflow == 0) return; 448 if (overflow == 0) return;
395 449
396 Trace((stderr,"\nbit length overflow\n")); 450 Trace((stderr,"\nbit length overflow\n"));
397 /* This happens for example on obj2 and pi 451 /* This happens for example on obj2 and pic of the Calgary corpus */
398 452
399 /* Find the first bit length which could i 453 /* Find the first bit length which could increase: */
400 do { 454 do {
401 bits = max_length-1; 455 bits = max_length-1;
402 while (s->bl_count[bits] == 0) bits--; 456 while (s->bl_count[bits] == 0) bits--;
403 s->bl_count[bits]--; /* move one 457 s->bl_count[bits]--; /* move one leaf down the tree */
404 s->bl_count[bits+1] += 2; /* move one 458 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
405 s->bl_count[max_length]--; 459 s->bl_count[max_length]--;
406 /* The brother of the overflow item al 460 /* The brother of the overflow item also moves one step up,
407 * but this does not affect bl_count[m 461 * but this does not affect bl_count[max_length]
408 */ 462 */
409 overflow -= 2; 463 overflow -= 2;
410 } while (overflow > 0); 464 } while (overflow > 0);
411 465
412 /* Now recompute all bit lengths, scanning 466 /* Now recompute all bit lengths, scanning in increasing frequency.
413 * h is still equal to HEAP_SIZE. (It is s 467 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
414 * lengths instead of fixing only the wron 468 * lengths instead of fixing only the wrong ones. This idea is taken
415 * from 'ar' written by Haruhiko Okumura.) 469 * from 'ar' written by Haruhiko Okumura.)
416 */ 470 */
417 for (bits = max_length; bits != 0; bits--) 471 for (bits = max_length; bits != 0; bits--) {
418 n = s->bl_count[bits]; 472 n = s->bl_count[bits];
419 while (n != 0) { 473 while (n != 0) {
420 m = s->heap[--h]; 474 m = s->heap[--h];
421 if (m > max_code) continue; 475 if (m > max_code) continue;
422 if (tree[m].Len != (unsigned) bits 476 if (tree[m].Len != (unsigned) bits) {
423 Trace((stderr,"code %d bits %d 477 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
424 s->opt_len += ((long)bits - (l 478 s->opt_len += ((long)bits - (long)tree[m].Len)
425 *(long)tree[m].F 479 *(long)tree[m].Freq;
426 tree[m].Len = (ush)bits; 480 tree[m].Len = (ush)bits;
427 } 481 }
428 n--; 482 n--;
429 } 483 }
430 } 484 }
431 } 485 }
432 486
433 /* =========================================== 487 /* ===========================================================================
434 * Generate the codes for a given tree and bit 488 * Generate the codes for a given tree and bit counts (which need not be
435 * optimal). 489 * optimal).
436 * IN assertion: the array bl_count contains t 490 * IN assertion: the array bl_count contains the bit length statistics for
437 * the given tree and the field len is set for 491 * the given tree and the field len is set for all tree elements.
438 * OUT assertion: the field code is set for al 492 * OUT assertion: the field code is set for all tree elements of non
439 * zero code length. 493 * zero code length.
440 */ 494 */
441 static void gen_codes( 495 static void gen_codes(
442 ct_data *tree, /* the tree 496 ct_data *tree, /* the tree to decorate */
443 int max_code, /* largest 497 int max_code, /* largest code with non zero frequency */
444 ush *bl_count /* number of 498 ush *bl_count /* number of codes at each bit length */
445 ) 499 )
446 { 500 {
447 ush next_code[MAX_BITS+1]; /* next code va 501 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
448 ush code = 0; /* running code 502 ush code = 0; /* running code value */
449 int bits; /* bit index */ 503 int bits; /* bit index */
450 int n; /* code index * 504 int n; /* code index */
451 505
452 /* The distribution counts are first used 506 /* The distribution counts are first used to generate the code values
453 * without bit reversal. 507 * without bit reversal.
454 */ 508 */
455 for (bits = 1; bits <= MAX_BITS; bits++) { 509 for (bits = 1; bits <= MAX_BITS; bits++) {
456 next_code[bits] = code = (code + bl_co 510 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
457 } 511 }
458 /* Check that the bit counts in bl_count a 512 /* Check that the bit counts in bl_count are consistent. The last code
459 * must be all ones. 513 * must be all ones.
460 */ 514 */
461 Assert (code + bl_count[MAX_BITS]-1 == (1< 515 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
462 "inconsistent bit counts"); 516 "inconsistent bit counts");
463 Tracev((stderr,"\ngen_codes: max_code %d " 517 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
464 518
465 for (n = 0; n <= max_code; n++) { 519 for (n = 0; n <= max_code; n++) {
466 int len = tree[n].Len; 520 int len = tree[n].Len;
467 if (len == 0) continue; 521 if (len == 0) continue;
468 /* Now reverse the bits */ 522 /* Now reverse the bits */
469 tree[n].Code = bitrev32((u32)(next_cod 523 tree[n].Code = bitrev32((u32)(next_code[len]++)) >> (32 - len);
470 524
471 Tracecv(tree != static_ltree, (stderr, 525 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
472 n, (isgraph(n) ? n : ' '), len, t 526 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
473 } 527 }
474 } 528 }
475 529
476 /* =========================================== 530 /* ===========================================================================
477 * Construct one Huffman tree and assigns the 531 * Construct one Huffman tree and assigns the code bit strings and lengths.
478 * Update the total bit length for the current 532 * Update the total bit length for the current block.
479 * IN assertion: the field freq is set for all 533 * IN assertion: the field freq is set for all tree elements.
480 * OUT assertions: the fields len and code are 534 * OUT assertions: the fields len and code are set to the optimal bit length
481 * and corresponding code. The length opt_ 535 * and corresponding code. The length opt_len is updated; static_len is
482 * also updated if stree is not null. The 536 * also updated if stree is not null. The field max_code is set.
483 */ 537 */
484 static void build_tree( 538 static void build_tree(
485 deflate_state *s, 539 deflate_state *s,
486 tree_desc *desc /* the tree descripto 540 tree_desc *desc /* the tree descriptor */
487 ) 541 )
488 { 542 {
489 ct_data *tree = desc->dyn_tree; 543 ct_data *tree = desc->dyn_tree;
490 const ct_data *stree = desc->stat_desc->s 544 const ct_data *stree = desc->stat_desc->static_tree;
491 int elems = desc->stat_desc->e 545 int elems = desc->stat_desc->elems;
492 int n, m; /* iterate over heap el 546 int n, m; /* iterate over heap elements */
493 int max_code = -1; /* largest code with no 547 int max_code = -1; /* largest code with non zero frequency */
494 int node; /* new node being creat 548 int node; /* new node being created */
495 549
496 /* Construct the initial heap, with least 550 /* Construct the initial heap, with least frequent element in
497 * heap[SMALLEST]. The sons of heap[n] are 551 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
498 * heap[0] is not used. 552 * heap[0] is not used.
499 */ 553 */
500 s->heap_len = 0, s->heap_max = HEAP_SIZE; 554 s->heap_len = 0, s->heap_max = HEAP_SIZE;
501 555
502 for (n = 0; n < elems; n++) { 556 for (n = 0; n < elems; n++) {
503 if (tree[n].Freq != 0) { 557 if (tree[n].Freq != 0) {
504 s->heap[++(s->heap_len)] = max_cod 558 s->heap[++(s->heap_len)] = max_code = n;
505 s->depth[n] = 0; 559 s->depth[n] = 0;
506 } else { 560 } else {
507 tree[n].Len = 0; 561 tree[n].Len = 0;
508 } 562 }
509 } 563 }
510 564
511 /* The pkzip format requires that at least 565 /* The pkzip format requires that at least one distance code exists,
512 * and that at least one bit should be sen 566 * and that at least one bit should be sent even if there is only one
513 * possible code. So to avoid special chec 567 * possible code. So to avoid special checks later on we force at least
514 * two codes of non zero frequency. 568 * two codes of non zero frequency.
515 */ 569 */
516 while (s->heap_len < 2) { 570 while (s->heap_len < 2) {
517 node = s->heap[++(s->heap_len)] = (max 571 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
518 tree[node].Freq = 1; 572 tree[node].Freq = 1;
519 s->depth[node] = 0; 573 s->depth[node] = 0;
520 s->opt_len--; if (stree) s->static_len 574 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
521 /* node is 0 or 1 so it does not have 575 /* node is 0 or 1 so it does not have extra bits */
522 } 576 }
523 desc->max_code = max_code; 577 desc->max_code = max_code;
524 578
525 /* The elements heap[heap_len/2+1 .. heap_ 579 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
526 * establish sub-heaps of increasing lengt 580 * establish sub-heaps of increasing lengths:
527 */ 581 */
528 for (n = s->heap_len/2; n >= 1; n--) pqdow 582 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
529 583
530 /* Construct the Huffman tree by repeatedl 584 /* Construct the Huffman tree by repeatedly combining the least two
531 * frequent nodes. 585 * frequent nodes.
532 */ 586 */
533 node = elems; /* next interna 587 node = elems; /* next internal node of the tree */
534 do { 588 do {
535 pqremove(s, tree, n); /* n = node of 589 pqremove(s, tree, n); /* n = node of least frequency */
536 m = s->heap[SMALLEST]; /* m = node of 590 m = s->heap[SMALLEST]; /* m = node of next least frequency */
537 591
538 s->heap[--(s->heap_max)] = n; /* keep 592 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
539 s->heap[--(s->heap_max)] = m; 593 s->heap[--(s->heap_max)] = m;
540 594
541 /* Create a new node father of n and m 595 /* Create a new node father of n and m */
542 tree[node].Freq = tree[n].Freq + tree[ 596 tree[node].Freq = tree[n].Freq + tree[m].Freq;
543 s->depth[node] = (uch) (max(s->depth[n 597 s->depth[node] = (uch) (max(s->depth[n], s->depth[m]) + 1);
544 tree[n].Dad = tree[m].Dad = (ush)node; 598 tree[n].Dad = tree[m].Dad = (ush)node;
545 #ifdef DUMP_BL_TREE 599 #ifdef DUMP_BL_TREE
546 if (tree == s->bl_tree) { 600 if (tree == s->bl_tree) {
547 fprintf(stderr,"\nnode %d(%d), son 601 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
548 node, tree[node].Freq, n, 602 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
549 } 603 }
550 #endif 604 #endif
551 /* and insert the new node in the heap 605 /* and insert the new node in the heap */
552 s->heap[SMALLEST] = node++; 606 s->heap[SMALLEST] = node++;
553 pqdownheap(s, tree, SMALLEST); 607 pqdownheap(s, tree, SMALLEST);
554 608
555 } while (s->heap_len >= 2); 609 } while (s->heap_len >= 2);
556 610
557 s->heap[--(s->heap_max)] = s->heap[SMALLES 611 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
558 612
559 /* At this point, the fields freq and dad 613 /* At this point, the fields freq and dad are set. We can now
560 * generate the bit lengths. 614 * generate the bit lengths.
561 */ 615 */
562 gen_bitlen(s, (tree_desc *)desc); 616 gen_bitlen(s, (tree_desc *)desc);
563 617
564 /* The field len is now set, we can genera 618 /* The field len is now set, we can generate the bit codes */
565 gen_codes ((ct_data *)tree, max_code, s->b 619 gen_codes ((ct_data *)tree, max_code, s->bl_count);
566 } 620 }
567 621
568 /* =========================================== 622 /* ===========================================================================
569 * Scan a literal or distance tree to determin 623 * Scan a literal or distance tree to determine the frequencies of the codes
570 * in the bit length tree. 624 * in the bit length tree.
571 */ 625 */
572 static void scan_tree( 626 static void scan_tree(
573 deflate_state *s, 627 deflate_state *s,
574 ct_data *tree, /* the tree to be sca 628 ct_data *tree, /* the tree to be scanned */
575 int max_code /* and its largest co 629 int max_code /* and its largest code of non zero frequency */
576 ) 630 )
577 { 631 {
578 int n; /* iterates ove 632 int n; /* iterates over all tree elements */
579 int prevlen = -1; /* last emitted 633 int prevlen = -1; /* last emitted length */
580 int curlen; /* length of cu 634 int curlen; /* length of current code */
581 int nextlen = tree[0].Len; /* length of ne 635 int nextlen = tree[0].Len; /* length of next code */
582 int count = 0; /* repeat count 636 int count = 0; /* repeat count of the current code */
583 int max_count = 7; /* max repeat c 637 int max_count = 7; /* max repeat count */
584 int min_count = 4; /* min repeat c 638 int min_count = 4; /* min repeat count */
585 639
586 if (nextlen == 0) max_count = 138, min_cou 640 if (nextlen == 0) max_count = 138, min_count = 3;
587 tree[max_code+1].Len = (ush)0xffff; /* gua 641 tree[max_code+1].Len = (ush)0xffff; /* guard */
588 642
589 for (n = 0; n <= max_code; n++) { 643 for (n = 0; n <= max_code; n++) {
590 curlen = nextlen; nextlen = tree[n+1]. 644 curlen = nextlen; nextlen = tree[n+1].Len;
591 if (++count < max_count && curlen == n 645 if (++count < max_count && curlen == nextlen) {
592 continue; 646 continue;
593 } else if (count < min_count) { 647 } else if (count < min_count) {
594 s->bl_tree[curlen].Freq += count; 648 s->bl_tree[curlen].Freq += count;
595 } else if (curlen != 0) { 649 } else if (curlen != 0) {
596 if (curlen != prevlen) s->bl_tree[ 650 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
597 s->bl_tree[REP_3_6].Freq++; 651 s->bl_tree[REP_3_6].Freq++;
598 } else if (count <= 10) { 652 } else if (count <= 10) {
599 s->bl_tree[REPZ_3_10].Freq++; 653 s->bl_tree[REPZ_3_10].Freq++;
600 } else { 654 } else {
601 s->bl_tree[REPZ_11_138].Freq++; 655 s->bl_tree[REPZ_11_138].Freq++;
602 } 656 }
603 count = 0; prevlen = curlen; 657 count = 0; prevlen = curlen;
604 if (nextlen == 0) { 658 if (nextlen == 0) {
605 max_count = 138, min_count = 3; 659 max_count = 138, min_count = 3;
606 } else if (curlen == nextlen) { 660 } else if (curlen == nextlen) {
607 max_count = 6, min_count = 3; 661 max_count = 6, min_count = 3;
608 } else { 662 } else {
609 max_count = 7, min_count = 4; 663 max_count = 7, min_count = 4;
610 } 664 }
611 } 665 }
612 } 666 }
613 667
614 /* =========================================== 668 /* ===========================================================================
615 * Send a literal or distance tree in compress 669 * Send a literal or distance tree in compressed form, using the codes in
616 * bl_tree. 670 * bl_tree.
617 */ 671 */
618 static void send_tree( 672 static void send_tree(
619 deflate_state *s, 673 deflate_state *s,
620 ct_data *tree, /* the tree to be scann 674 ct_data *tree, /* the tree to be scanned */
621 int max_code /* and its largest code 675 int max_code /* and its largest code of non zero frequency */
622 ) 676 )
623 { 677 {
624 int n; /* iterates ove 678 int n; /* iterates over all tree elements */
625 int prevlen = -1; /* last emitted 679 int prevlen = -1; /* last emitted length */
626 int curlen; /* length of cu 680 int curlen; /* length of current code */
627 int nextlen = tree[0].Len; /* length of ne 681 int nextlen = tree[0].Len; /* length of next code */
628 int count = 0; /* repeat count 682 int count = 0; /* repeat count of the current code */
629 int max_count = 7; /* max repeat c 683 int max_count = 7; /* max repeat count */
630 int min_count = 4; /* min repeat c 684 int min_count = 4; /* min repeat count */
631 685
632 /* tree[max_code+1].Len = -1; */ /* guard 686 /* tree[max_code+1].Len = -1; */ /* guard already set */
633 if (nextlen == 0) max_count = 138, min_cou 687 if (nextlen == 0) max_count = 138, min_count = 3;
634 688
635 for (n = 0; n <= max_code; n++) { 689 for (n = 0; n <= max_code; n++) {
636 curlen = nextlen; nextlen = tree[n+1]. 690 curlen = nextlen; nextlen = tree[n+1].Len;
637 if (++count < max_count && curlen == n 691 if (++count < max_count && curlen == nextlen) {
638 continue; 692 continue;
639 } else if (count < min_count) { 693 } else if (count < min_count) {
640 do { send_code(s, curlen, s->bl_tr 694 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
641 695
642 } else if (curlen != 0) { 696 } else if (curlen != 0) {
643 if (curlen != prevlen) { 697 if (curlen != prevlen) {
644 send_code(s, curlen, s->bl_tre 698 send_code(s, curlen, s->bl_tree); count--;
645 } 699 }
646 Assert(count >= 3 && count <= 6, " 700 Assert(count >= 3 && count <= 6, " 3_6?");
647 send_code(s, REP_3_6, s->bl_tree); 701 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
648 702
649 } else if (count <= 10) { 703 } else if (count <= 10) {
650 send_code(s, REPZ_3_10, s->bl_tree 704 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
651 705
652 } else { 706 } else {
653 send_code(s, REPZ_11_138, s->bl_tr 707 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
654 } 708 }
655 count = 0; prevlen = curlen; 709 count = 0; prevlen = curlen;
656 if (nextlen == 0) { 710 if (nextlen == 0) {
657 max_count = 138, min_count = 3; 711 max_count = 138, min_count = 3;
658 } else if (curlen == nextlen) { 712 } else if (curlen == nextlen) {
659 max_count = 6, min_count = 3; 713 max_count = 6, min_count = 3;
660 } else { 714 } else {
661 max_count = 7, min_count = 4; 715 max_count = 7, min_count = 4;
662 } 716 }
663 } 717 }
664 } 718 }
665 719
666 /* =========================================== 720 /* ===========================================================================
667 * Construct the Huffman tree for the bit leng 721 * Construct the Huffman tree for the bit lengths and return the index in
668 * bl_order of the last bit length code to sen 722 * bl_order of the last bit length code to send.
669 */ 723 */
670 static int build_bl_tree( 724 static int build_bl_tree(
671 deflate_state *s 725 deflate_state *s
672 ) 726 )
673 { 727 {
674 int max_blindex; /* index of last bit len 728 int max_blindex; /* index of last bit length code of non zero freq */
675 729
676 /* Determine the bit length frequencies fo 730 /* Determine the bit length frequencies for literal and distance trees */
677 scan_tree(s, (ct_data *)s->dyn_ltree, s->l 731 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
678 scan_tree(s, (ct_data *)s->dyn_dtree, s->d 732 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
679 733
680 /* Build the bit length tree: */ 734 /* Build the bit length tree: */
681 build_tree(s, (tree_desc *)(&(s->bl_desc)) 735 build_tree(s, (tree_desc *)(&(s->bl_desc)));
682 /* opt_len now includes the length of the 736 /* opt_len now includes the length of the tree representations, except
683 * the lengths of the bit lengths codes an 737 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
684 */ 738 */
685 739
686 /* Determine the number of bit length code 740 /* Determine the number of bit length codes to send. The pkzip format
687 * requires that at least 4 bit length cod 741 * requires that at least 4 bit length codes be sent. (appnote.txt says
688 * 3 but the actual value used is 4.) 742 * 3 but the actual value used is 4.)
689 */ 743 */
690 for (max_blindex = BL_CODES-1; max_blindex 744 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
691 if (s->bl_tree[bl_order[max_blindex]]. 745 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
692 } 746 }
693 /* Update opt_len to include the bit lengt 747 /* Update opt_len to include the bit length tree and counts */
694 s->opt_len += 3*(max_blindex+1) + 5+5+4; 748 s->opt_len += 3*(max_blindex+1) + 5+5+4;
695 Tracev((stderr, "\ndyn trees: dyn %ld, sta 749 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
696 s->opt_len, s->static_len)); 750 s->opt_len, s->static_len));
697 751
698 return max_blindex; 752 return max_blindex;
699 } 753 }
700 754
701 /* =========================================== 755 /* ===========================================================================
702 * Send the header for a block using dynamic H 756 * Send the header for a block using dynamic Huffman trees: the counts, the
703 * lengths of the bit length codes, the litera 757 * lengths of the bit length codes, the literal tree and the distance tree.
704 * IN assertion: lcodes >= 257, dcodes >= 1, b 758 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
705 */ 759 */
706 static void send_all_trees( 760 static void send_all_trees(
707 deflate_state *s, 761 deflate_state *s,
708 int lcodes, /* number of codes for ea 762 int lcodes, /* number of codes for each tree */
709 int dcodes, /* number of codes for ea 763 int dcodes, /* number of codes for each tree */
710 int blcodes /* number of codes for ea 764 int blcodes /* number of codes for each tree */
711 ) 765 )
712 { 766 {
713 int rank; /* index in b 767 int rank; /* index in bl_order */
714 768
715 Assert (lcodes >= 257 && dcodes >= 1 && bl 769 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
716 Assert (lcodes <= L_CODES && dcodes <= D_C 770 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
717 "too many codes"); 771 "too many codes");
718 Tracev((stderr, "\nbl counts: ")); 772 Tracev((stderr, "\nbl counts: "));
719 send_bits(s, lcodes-257, 5); /* not +255 a 773 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
720 send_bits(s, dcodes-1, 5); 774 send_bits(s, dcodes-1, 5);
721 send_bits(s, blcodes-4, 4); /* not -3 as 775 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
722 for (rank = 0; rank < blcodes; rank++) { 776 for (rank = 0; rank < blcodes; rank++) {
723 Tracev((stderr, "\nbl code %2d ", bl_o 777 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
724 send_bits(s, s->bl_tree[bl_order[rank] 778 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
725 } 779 }
726 Tracev((stderr, "\nbl tree: sent %ld", s-> 780 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
727 781
728 send_tree(s, (ct_data *)s->dyn_ltree, lcod 782 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
729 Tracev((stderr, "\nlit tree: sent %ld", s- 783 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
730 784
731 send_tree(s, (ct_data *)s->dyn_dtree, dcod 785 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
732 Tracev((stderr, "\ndist tree: sent %ld", s 786 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
733 } 787 }
734 788
735 /* =========================================== 789 /* ===========================================================================
736 * Send a stored block 790 * Send a stored block
737 */ 791 */
738 void zlib_tr_stored_block( 792 void zlib_tr_stored_block(
739 deflate_state *s, 793 deflate_state *s,
740 char *buf, /* input block */ 794 char *buf, /* input block */
741 ulg stored_len, /* length of input b 795 ulg stored_len, /* length of input block */
742 int eof /* true if this is t 796 int eof /* true if this is the last block for a file */
743 ) 797 )
744 { 798 {
745 send_bits(s, (STORED_BLOCK<<1)+eof, 3); / 799 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
746 s->compressed_len = (s->compressed_len + 3 800 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
747 s->compressed_len += (stored_len + 4) << 3 801 s->compressed_len += (stored_len + 4) << 3;
748 802
749 copy_block(s, buf, (unsigned)stored_len, 1 803 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
750 } 804 }
751 805
752 /* Send just the `stored block' type code with 806 /* Send just the `stored block' type code without any length bytes or data.
753 */ 807 */
754 void zlib_tr_stored_type_only( 808 void zlib_tr_stored_type_only(
755 deflate_state *s 809 deflate_state *s
756 ) 810 )
757 { 811 {
758 send_bits(s, (STORED_BLOCK << 1), 3); 812 send_bits(s, (STORED_BLOCK << 1), 3);
759 bi_windup(s); 813 bi_windup(s);
760 s->compressed_len = (s->compressed_len + 3 814 s->compressed_len = (s->compressed_len + 3) & ~7L;
761 } 815 }
762 816
763 817
764 /* =========================================== 818 /* ===========================================================================
765 * Send one empty static block to give enough 819 * Send one empty static block to give enough lookahead for inflate.
766 * This takes 10 bits, of which 7 may remain i 820 * This takes 10 bits, of which 7 may remain in the bit buffer.
767 * The current inflate code requires 9 bits of 821 * The current inflate code requires 9 bits of lookahead. If the
768 * last two codes for the previous block (real 822 * last two codes for the previous block (real code plus EOB) were coded
769 * on 5 bits or less, inflate may have only 5+ 823 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
770 * the last real code. In this case we send tw 824 * the last real code. In this case we send two empty static blocks instead
771 * of one. (There are no problems if the previ 825 * of one. (There are no problems if the previous block is stored or fixed.)
772 * To simplify the code, we assume the worst c 826 * To simplify the code, we assume the worst case of last real code encoded
773 * on one bit only. 827 * on one bit only.
774 */ 828 */
775 void zlib_tr_align( 829 void zlib_tr_align(
776 deflate_state *s 830 deflate_state *s
777 ) 831 )
778 { 832 {
779 send_bits(s, STATIC_TREES<<1, 3); 833 send_bits(s, STATIC_TREES<<1, 3);
780 send_code(s, END_BLOCK, static_ltree); 834 send_code(s, END_BLOCK, static_ltree);
781 s->compressed_len += 10L; /* 3 for block t 835 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
782 bi_flush(s); 836 bi_flush(s);
783 /* Of the 10 bits for the empty block, we 837 /* Of the 10 bits for the empty block, we have already sent
784 * (10 - bi_valid) bits. The lookahead for 838 * (10 - bi_valid) bits. The lookahead for the last real code (before
785 * the EOB of the previous block) was thus 839 * the EOB of the previous block) was thus at least one plus the length
786 * of the EOB plus what we have just sent 840 * of the EOB plus what we have just sent of the empty static block.
787 */ 841 */
788 if (1 + s->last_eob_len + 10 - s->bi_valid 842 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
789 send_bits(s, STATIC_TREES<<1, 3); 843 send_bits(s, STATIC_TREES<<1, 3);
790 send_code(s, END_BLOCK, static_ltree); 844 send_code(s, END_BLOCK, static_ltree);
791 s->compressed_len += 10L; 845 s->compressed_len += 10L;
792 bi_flush(s); 846 bi_flush(s);
793 } 847 }
794 s->last_eob_len = 7; 848 s->last_eob_len = 7;
795 } 849 }
796 850
797 /* =========================================== 851 /* ===========================================================================
798 * Determine the best encoding for the current 852 * Determine the best encoding for the current block: dynamic trees, static
799 * trees or store, and output the encoded bloc 853 * trees or store, and output the encoded block to the zip file. This function
800 * returns the total compressed length for the 854 * returns the total compressed length for the file so far.
801 */ 855 */
802 ulg zlib_tr_flush_block( 856 ulg zlib_tr_flush_block(
803 deflate_state *s, 857 deflate_state *s,
804 char *buf, /* input block, or N 858 char *buf, /* input block, or NULL if too old */
805 ulg stored_len, /* length of input b 859 ulg stored_len, /* length of input block */
806 int eof /* true if this is t 860 int eof /* true if this is the last block for a file */
807 ) 861 )
808 { 862 {
809 ulg opt_lenb, static_lenb; /* opt_len and 863 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
810 int max_blindex = 0; /* index of last bit 864 int max_blindex = 0; /* index of last bit length code of non zero freq */
811 865
812 /* Build the Huffman trees unless a stored 866 /* Build the Huffman trees unless a stored block is forced */
813 if (s->level > 0) { 867 if (s->level > 0) {
814 868
815 /* Check if the file is ascii or bina 869 /* Check if the file is ascii or binary */
816 if (s->data_type == Z_UNKNOWN) set_dat 870 if (s->data_type == Z_UNKNOWN) set_data_type(s);
817 871
818 /* Construct the literal and distance 872 /* Construct the literal and distance trees */
819 build_tree(s, (tree_desc *)(&(s->l_des 873 build_tree(s, (tree_desc *)(&(s->l_desc)));
820 Tracev((stderr, "\nlit data: dyn %ld, 874 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
821 s->static_len)); 875 s->static_len));
822 876
823 build_tree(s, (tree_desc *)(&(s->d_des 877 build_tree(s, (tree_desc *)(&(s->d_desc)));
824 Tracev((stderr, "\ndist data: dyn %ld, 878 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
825 s->static_len)); 879 s->static_len));
826 /* At this point, opt_len and static_l 880 /* At this point, opt_len and static_len are the total bit lengths of
827 * the compressed block data, excludin 881 * the compressed block data, excluding the tree representations.
828 */ 882 */
829 883
830 /* Build the bit length tree for the a 884 /* Build the bit length tree for the above two trees, and get the index
831 * in bl_order of the last bit length 885 * in bl_order of the last bit length code to send.
832 */ 886 */
833 max_blindex = build_bl_tree(s); 887 max_blindex = build_bl_tree(s);
834 888
835 /* Determine the best encoding. Comput 889 /* Determine the best encoding. Compute first the block length in bytes*/
836 opt_lenb = (s->opt_len+3+7)>>3; 890 opt_lenb = (s->opt_len+3+7)>>3;
837 static_lenb = (s->static_len+3+7)>>3; 891 static_lenb = (s->static_len+3+7)>>3;
838 892
839 Tracev((stderr, "\nopt %lu(%lu) stat % 893 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
840 opt_lenb, s->opt_len, static_l 894 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
841 s->last_lit)); 895 s->last_lit));
842 896
843 if (static_lenb <= opt_lenb) opt_lenb 897 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
844 898
845 } else { 899 } else {
846 Assert(buf != (char*)0, "lost buf"); 900 Assert(buf != (char*)0, "lost buf");
847 opt_lenb = static_lenb = stored_len + 901 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
848 } 902 }
849 903
850 /* If compression failed and this is the f 904 /* If compression failed and this is the first and last block,
851 * and if the .zip file can be seeked (to 905 * and if the .zip file can be seeked (to rewrite the local header),
852 * the whole file is transformed into a st 906 * the whole file is transformed into a stored file:
853 */ 907 */
854 #ifdef STORED_FILE_OK 908 #ifdef STORED_FILE_OK
855 # ifdef FORCE_STORED_FILE 909 # ifdef FORCE_STORED_FILE
856 if (eof && s->compressed_len == 0L) { /* f 910 if (eof && s->compressed_len == 0L) { /* force stored file */
857 # else 911 # else
858 if (stored_len <= opt_lenb && eof && s->co 912 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
859 # endif 913 # endif
860 /* Since LIT_BUFSIZE <= 2*WSIZE, the i 914 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
861 if (buf == (char*)0) error ("block van 915 if (buf == (char*)0) error ("block vanished");
862 916
863 copy_block(s, buf, (unsigned)stored_le 917 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
864 s->compressed_len = stored_len << 3; 918 s->compressed_len = stored_len << 3;
865 s->method = STORED; 919 s->method = STORED;
866 } else 920 } else
867 #endif /* STORED_FILE_OK */ 921 #endif /* STORED_FILE_OK */
868 922
869 #ifdef FORCE_STORED 923 #ifdef FORCE_STORED
870 if (buf != (char*)0) { /* force stored blo 924 if (buf != (char*)0) { /* force stored block */
871 #else 925 #else
872 if (stored_len+4 <= opt_lenb && buf != (ch 926 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
873 /* 4: two words for the 927 /* 4: two words for the lengths */
874 #endif 928 #endif
875 /* The test buf != NULL is only necess 929 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
876 * Otherwise we can't have processed m 930 * Otherwise we can't have processed more than WSIZE input bytes since
877 * the last block flush, because compr 931 * the last block flush, because compression would have been
878 * successful. If LIT_BUFSIZE <= WSIZE 932 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
879 * transform a block into a stored blo 933 * transform a block into a stored block.
880 */ 934 */
881 zlib_tr_stored_block(s, buf, stored_le 935 zlib_tr_stored_block(s, buf, stored_len, eof);
882 936
883 #ifdef FORCE_STATIC 937 #ifdef FORCE_STATIC
884 } else if (static_lenb >= 0) { /* force st 938 } else if (static_lenb >= 0) { /* force static trees */
885 #else 939 #else
886 } else if (static_lenb == opt_lenb) { 940 } else if (static_lenb == opt_lenb) {
887 #endif 941 #endif
888 send_bits(s, (STATIC_TREES<<1)+eof, 3) 942 send_bits(s, (STATIC_TREES<<1)+eof, 3);
889 compress_block(s, (ct_data *)static_lt 943 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
890 s->compressed_len += 3 + s->static_len 944 s->compressed_len += 3 + s->static_len;
891 } else { 945 } else {
892 send_bits(s, (DYN_TREES<<1)+eof, 3); 946 send_bits(s, (DYN_TREES<<1)+eof, 3);
893 send_all_trees(s, s->l_desc.max_code+1 947 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
894 max_blindex+1); 948 max_blindex+1);
895 compress_block(s, (ct_data *)s->dyn_lt 949 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
896 s->compressed_len += 3 + s->opt_len; 950 s->compressed_len += 3 + s->opt_len;
897 } 951 }
898 Assert (s->compressed_len == s->bits_sent, 952 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
899 init_block(s); 953 init_block(s);
900 954
901 if (eof) { 955 if (eof) {
902 bi_windup(s); 956 bi_windup(s);
903 s->compressed_len += 7; /* align on b 957 s->compressed_len += 7; /* align on byte boundary */
904 } 958 }
905 Tracev((stderr,"\ncomprlen %lu(%lu) ", s-> 959 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
906 s->compressed_len-7*eof)); 960 s->compressed_len-7*eof));
907 961
908 return s->compressed_len >> 3; 962 return s->compressed_len >> 3;
909 } 963 }
910 964
911 /* =========================================== 965 /* ===========================================================================
912 * Save the match info and tally the frequency 966 * Save the match info and tally the frequency counts. Return true if
913 * the current block must be flushed. 967 * the current block must be flushed.
914 */ 968 */
915 int zlib_tr_tally( 969 int zlib_tr_tally(
916 deflate_state *s, 970 deflate_state *s,
917 unsigned dist, /* distance of matched 971 unsigned dist, /* distance of matched string */
918 unsigned lc /* match length-MIN_MA 972 unsigned lc /* match length-MIN_MATCH or unmatched char (if dist==0) */
919 ) 973 )
920 { 974 {
921 s->d_buf[s->last_lit] = (ush)dist; 975 s->d_buf[s->last_lit] = (ush)dist;
922 s->l_buf[s->last_lit++] = (uch)lc; 976 s->l_buf[s->last_lit++] = (uch)lc;
923 if (dist == 0) { 977 if (dist == 0) {
924 /* lc is the unmatched char */ 978 /* lc is the unmatched char */
925 s->dyn_ltree[lc].Freq++; 979 s->dyn_ltree[lc].Freq++;
926 } else { 980 } else {
927 s->matches++; 981 s->matches++;
928 /* Here, lc is the match length - MIN_ 982 /* Here, lc is the match length - MIN_MATCH */
929 dist--; /* dist = match di 983 dist--; /* dist = match distance - 1 */
930 Assert((ush)dist < (ush)MAX_DIST(s) && 984 Assert((ush)dist < (ush)MAX_DIST(s) &&
931 (ush)lc <= (ush)(MAX_MATCH-MIN_ 985 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
932 (ush)d_code(dist) < (ush)D_CODE 986 (ush)d_code(dist) < (ush)D_CODES, "zlib_tr_tally: bad match");
933 987
934 s->dyn_ltree[length_code[lc]+LITERALS+ 988 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
935 s->dyn_dtree[d_code(dist)].Freq++; 989 s->dyn_dtree[d_code(dist)].Freq++;
936 } 990 }
937 991
938 /* Try to guess if it is profitable to sto 992 /* Try to guess if it is profitable to stop the current block here */
939 if ((s->last_lit & 0xfff) == 0 && s->level 993 if ((s->last_lit & 0xfff) == 0 && s->level > 2) {
940 /* Compute an upper bound for the comp 994 /* Compute an upper bound for the compressed length */
941 ulg out_length = (ulg)s->last_lit*8L; 995 ulg out_length = (ulg)s->last_lit*8L;
942 ulg in_length = (ulg)((long)s->strstar 996 ulg in_length = (ulg)((long)s->strstart - s->block_start);
943 int dcode; 997 int dcode;
944 for (dcode = 0; dcode < D_CODES; dcode 998 for (dcode = 0; dcode < D_CODES; dcode++) {
945 out_length += (ulg)s->dyn_dtree[dc 999 out_length += (ulg)s->dyn_dtree[dcode].Freq *
946 (5L+extra_dbits[dcode]); 1000 (5L+extra_dbits[dcode]);
947 } 1001 }
948 out_length >>= 3; 1002 out_length >>= 3;
949 Tracev((stderr,"\nlast_lit %u, in %ld, 1003 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
950 s->last_lit, in_length, out_len 1004 s->last_lit, in_length, out_length,
951 100L - out_length*100L/in_lengt 1005 100L - out_length*100L/in_length));
952 if (s->matches < s->last_lit/2 && out_ 1006 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
953 } 1007 }
954 return (s->last_lit == s->lit_bufsize-1); 1008 return (s->last_lit == s->lit_bufsize-1);
955 /* We avoid equality with lit_bufsize beca 1009 /* We avoid equality with lit_bufsize because of wraparound at 64K
956 * on 16 bit machines and because stored b 1010 * on 16 bit machines and because stored blocks are restricted to
957 * 64K-1 bytes. 1011 * 64K-1 bytes.
958 */ 1012 */
959 } 1013 }
960 1014
961 /* =========================================== 1015 /* ===========================================================================
962 * Send the block data compressed using the gi 1016 * Send the block data compressed using the given Huffman trees
963 */ 1017 */
964 static void compress_block( 1018 static void compress_block(
965 deflate_state *s, 1019 deflate_state *s,
966 ct_data *ltree, /* literal tree */ 1020 ct_data *ltree, /* literal tree */
967 ct_data *dtree /* distance tree */ 1021 ct_data *dtree /* distance tree */
968 ) 1022 )
969 { 1023 {
970 unsigned dist; /* distance of matched 1024 unsigned dist; /* distance of matched string */
971 int lc; /* match length or unm 1025 int lc; /* match length or unmatched char (if dist == 0) */
972 unsigned lx = 0; /* running index in l_ 1026 unsigned lx = 0; /* running index in l_buf */
973 unsigned code; /* the code to send */ 1027 unsigned code; /* the code to send */
974 int extra; /* number of extra bit 1028 int extra; /* number of extra bits to send */
975 1029
976 if (s->last_lit != 0) do { 1030 if (s->last_lit != 0) do {
977 dist = s->d_buf[lx]; 1031 dist = s->d_buf[lx];
978 lc = s->l_buf[lx++]; 1032 lc = s->l_buf[lx++];
979 if (dist == 0) { 1033 if (dist == 0) {
980 send_code(s, lc, ltree); /* send a 1034 send_code(s, lc, ltree); /* send a literal byte */
981 Tracecv(isgraph(lc), (stderr," '%c 1035 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
982 } else { 1036 } else {
983 /* Here, lc is the match length - 1037 /* Here, lc is the match length - MIN_MATCH */
984 code = length_code[lc]; 1038 code = length_code[lc];
985 send_code(s, code+LITERALS+1, ltre 1039 send_code(s, code+LITERALS+1, ltree); /* send the length code */
986 extra = extra_lbits[code]; 1040 extra = extra_lbits[code];
987 if (extra != 0) { 1041 if (extra != 0) {
988 lc -= base_length[code]; 1042 lc -= base_length[code];
989 send_bits(s, lc, extra); 1043 send_bits(s, lc, extra); /* send the extra length bits */
990 } 1044 }
991 dist--; /* dist is now the match d 1045 dist--; /* dist is now the match distance - 1 */
992 code = d_code(dist); 1046 code = d_code(dist);
993 Assert (code < D_CODES, "bad d_cod 1047 Assert (code < D_CODES, "bad d_code");
994 1048
995 send_code(s, code, dtree); / 1049 send_code(s, code, dtree); /* send the distance code */
996 extra = extra_dbits[code]; 1050 extra = extra_dbits[code];
997 if (extra != 0) { 1051 if (extra != 0) {
998 dist -= base_dist[code]; 1052 dist -= base_dist[code];
999 send_bits(s, dist, extra); / 1053 send_bits(s, dist, extra); /* send the extra distance bits */
1000 } 1054 }
1001 } /* literal or match pair ? */ 1055 } /* literal or match pair ? */
1002 1056
1003 /* Check that the overlay between pen 1057 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
1004 Assert(s->pending < s->lit_bufsize + 1058 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
1005 1059
1006 } while (lx < s->last_lit); 1060 } while (lx < s->last_lit);
1007 1061
1008 send_code(s, END_BLOCK, ltree); 1062 send_code(s, END_BLOCK, ltree);
1009 s->last_eob_len = ltree[END_BLOCK].Len; 1063 s->last_eob_len = ltree[END_BLOCK].Len;
1010 } 1064 }
1011 1065
1012 /* ========================================== 1066 /* ===========================================================================
1013 * Set the data type to ASCII or BINARY, usin 1067 * Set the data type to ASCII or BINARY, using a crude approximation:
1014 * binary if more than 20% of the bytes are < 1068 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
1015 * IN assertion: the fields freq of dyn_ltree 1069 * IN assertion: the fields freq of dyn_ltree are set and the total of all
1016 * frequencies does not exceed 64K (to fit in 1070 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
1017 */ 1071 */
1018 static void set_data_type( 1072 static void set_data_type(
1019 deflate_state *s 1073 deflate_state *s
1020 ) 1074 )
1021 { 1075 {
1022 int n = 0; 1076 int n = 0;
1023 unsigned ascii_freq = 0; 1077 unsigned ascii_freq = 0;
1024 unsigned bin_freq = 0; 1078 unsigned bin_freq = 0;
1025 while (n < 7) bin_freq += s->dyn_l 1079 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
1026 while (n < 128) ascii_freq += s->dyn_l 1080 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
1027 while (n < LITERALS) bin_freq += s->dyn_l 1081 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
1028 s->data_type = (Byte)(bin_freq > (ascii_f 1082 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
1029 } 1083 }
1030 1084
1031 /* ========================================== 1085 /* ===========================================================================
1032 * Copy a stored block, storing first the len 1086 * Copy a stored block, storing first the length and its
1033 * one's complement if requested. 1087 * one's complement if requested.
1034 */ 1088 */
1035 static void copy_block( 1089 static void copy_block(
1036 deflate_state *s, 1090 deflate_state *s,
1037 char *buf, /* the input data * 1091 char *buf, /* the input data */
1038 unsigned len, /* its length */ 1092 unsigned len, /* its length */
1039 int header /* true if block he 1093 int header /* true if block header must be written */
1040 ) 1094 )
1041 { 1095 {
1042 bi_windup(s); /* align on byte bou 1096 bi_windup(s); /* align on byte boundary */
1043 s->last_eob_len = 8; /* enough lookahead 1097 s->last_eob_len = 8; /* enough lookahead for inflate */
1044 1098
1045 if (header) { 1099 if (header) {
1046 put_short(s, (ush)len); 1100 put_short(s, (ush)len);
1047 put_short(s, (ush)~len); 1101 put_short(s, (ush)~len);
1048 #ifdef DEBUG_ZLIB 1102 #ifdef DEBUG_ZLIB
1049 s->bits_sent += 2*16; 1103 s->bits_sent += 2*16;
1050 #endif 1104 #endif
1051 } 1105 }
1052 #ifdef DEBUG_ZLIB 1106 #ifdef DEBUG_ZLIB
1053 s->bits_sent += (ulg)len<<3; 1107 s->bits_sent += (ulg)len<<3;
1054 #endif 1108 #endif
1055 /* bundle up the put_byte(s, *buf++) call 1109 /* bundle up the put_byte(s, *buf++) calls */
1056 memcpy(&s->pending_buf[s->pending], buf, 1110 memcpy(&s->pending_buf[s->pending], buf, len);
1057 s->pending += len; 1111 s->pending += len;
1058 } 1112 }
1059 1113
1060 1114
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