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jedi-academy/codemp/zlib32/deflate.cpp
Jonathan Gray 039ef2cb4a ditch dos style newlines
2013-04-23 15:21:39 +10:00

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#include "../game/q_shared.h"
#include "../qcommon/qcommon.h"
#include "zip.h"
#include "deflate.h"
#ifdef _TIMING
int totalDeflateTime[Z_MAX_COMPRESSION + 1];
int totalDeflateCount[Z_MAX_COMPRESSION + 1];
#endif
// If you use the zlib library in a product, an acknowledgment is welcome
// in the documentation of your product. If for some reason you cannot
// include such an acknowledgment, I would appreciate that you keep this
// copyright string in the executable of your product.
const char deflate_copyright[] = "Deflate 1.1.3 Copyright 1995-1998 Jean-loup Gailly ";
static const char *deflate_error = "OK";
// ALGORITHM
//
// The "deflation" process depends on being able to identify portions
// of the input text which are identical to earlier input (within a
// sliding window trailing behind the input currently being processed).
//
// The most straightforward technique turns out to be the fastest for
// most input files: try all possible matches and select the longest.
// The key feature of this algorithm is that insertions into the string
// dictionary are very simple and thus fast, and deletions are avoided
// completely. Insertions are performed at each input character, whereas
// string matches are performed only when the previous match ends. So it
// is preferable to spend more time in matches to allow very fast string
// insertions and avoid deletions. The matching algorithm for small
// strings is inspired from that of Rabin & Karp. A brute force approach
// is used to find longer strings when a small match has been found.
// A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
// (by Leonid Broukhis).
//
// ACKNOWLEDGEMENTS
//
// The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
// I found it in 'freeze' written by Leonid Broukhis.
// Thanks to many people for bug reports and testing.
//
// REFERENCES
//
// Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
// Available in ftp://ds.internic.net/rfc/rfc1951.txt
//
// A description of the Rabin and Karp algorithm is given in the book
// "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
//
// Fiala,E.R., and Greene,D.H.
// Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
// ===============================================================================
// A word is an index in the character window. We use short instead of int to
// save space in the various tables. ulong is used only for parameter passing.
// The static literal tree. Since the bit lengths are imposed, there is no
// need for the L_CODES extra codes used during heap construction. However
// The codes 286 and 287 are needed to build a canonical tree (see _tr_init
// below).
static const ct_data static_ltree[L_CODES + 2] =
{
{{ 12 }, { 8 }}, {{ 140 }, { 8 }}, {{ 76 }, { 8 }}, {{ 204 }, { 8 }}, {{ 44 }, { 8 }},
{{ 172 }, { 8 }}, {{ 108 }, { 8 }}, {{ 236 }, { 8 }}, {{ 28 }, { 8 }}, {{ 156 }, { 8 }},
{{ 92 }, { 8 }}, {{ 220 }, { 8 }}, {{ 60 }, { 8 }}, {{ 188 }, { 8 }}, {{ 124 }, { 8 }},
{{ 252 }, { 8 }}, {{ 2 }, { 8 }}, {{ 130 }, { 8 }}, {{ 66 }, { 8 }}, {{ 194 }, { 8 }},
{{ 34 }, { 8 }}, {{ 162 }, { 8 }}, {{ 98 }, { 8 }}, {{ 226 }, { 8 }}, {{ 18 }, { 8 }},
{{ 146 }, { 8 }}, {{ 82 }, { 8 }}, {{ 210 }, { 8 }}, {{ 50 }, { 8 }}, {{ 178 }, { 8 }},
{{ 114 }, { 8 }}, {{ 242 }, { 8 }}, {{ 10 }, { 8 }}, {{ 138 }, { 8 }}, {{ 74 }, { 8 }},
{{ 202 }, { 8 }}, {{ 42 }, { 8 }}, {{ 170 }, { 8 }}, {{ 106 }, { 8 }}, {{ 234 }, { 8 }},
{{ 26 }, { 8 }}, {{ 154 }, { 8 }}, {{ 90 }, { 8 }}, {{ 218 }, { 8 }}, {{ 58 }, { 8 }},
{{ 186 }, { 8 }}, {{ 122 }, { 8 }}, {{ 250 }, { 8 }}, {{ 6 }, { 8 }}, {{ 134 }, { 8 }},
{{ 70 }, { 8 }}, {{ 198 }, { 8 }}, {{ 38 }, { 8 }}, {{ 166 }, { 8 }}, {{ 102 }, { 8 }},
{{ 230 }, { 8 }}, {{ 22 }, { 8 }}, {{ 150 }, { 8 }}, {{ 86 }, { 8 }}, {{ 214 }, { 8 }},
{{ 54 }, { 8 }}, {{ 182 }, { 8 }}, {{ 118 }, { 8 }}, {{ 246 }, { 8 }}, {{ 14 }, { 8 }},
{{ 142 }, { 8 }}, {{ 78 }, { 8 }}, {{ 206 }, { 8 }}, {{ 46 }, { 8 }}, {{ 174 }, { 8 }},
{{ 110 }, { 8 }}, {{ 238 }, { 8 }}, {{ 30 }, { 8 }}, {{ 158 }, { 8 }}, {{ 94 }, { 8 }},
{{ 222 }, { 8 }}, {{ 62 }, { 8 }}, {{ 190 }, { 8 }}, {{ 126 }, { 8 }}, {{ 254 }, { 8 }},
{{ 1 }, { 8 }}, {{ 129 }, { 8 }}, {{ 65 }, { 8 }}, {{ 193 }, { 8 }}, {{ 33 }, { 8 }},
{{ 161 }, { 8 }}, {{ 97 }, { 8 }}, {{ 225 }, { 8 }}, {{ 17 }, { 8 }}, {{ 145 }, { 8 }},
{{ 81 }, { 8 }}, {{ 209 }, { 8 }}, {{ 49 }, { 8 }}, {{ 177 }, { 8 }}, {{ 113 }, { 8 }},
{{ 241 }, { 8 }}, {{ 9 }, { 8 }}, {{ 137 }, { 8 }}, {{ 73 }, { 8 }}, {{ 201 }, { 8 }},
{{ 41 }, { 8 }}, {{ 169 }, { 8 }}, {{ 105 }, { 8 }}, {{ 233 }, { 8 }}, {{ 25 }, { 8 }},
{{ 153 }, { 8 }}, {{ 89 }, { 8 }}, {{ 217 }, { 8 }}, {{ 57 }, { 8 }}, {{ 185 }, { 8 }},
{{ 121 }, { 8 }}, {{ 249 }, { 8 }}, {{ 5 }, { 8 }}, {{ 133 }, { 8 }}, {{ 69 }, { 8 }},
{{ 197 }, { 8 }}, {{ 37 }, { 8 }}, {{ 165 }, { 8 }}, {{ 101 }, { 8 }}, {{ 229 }, { 8 }},
{{ 21 }, { 8 }}, {{ 149 }, { 8 }}, {{ 85 }, { 8 }}, {{ 213 }, { 8 }}, {{ 53 }, { 8 }},
{{ 181 }, { 8 }}, {{ 117 }, { 8 }}, {{ 245 }, { 8 }}, {{ 13 }, { 8 }}, {{ 141 }, { 8 }},
{{ 77 }, { 8 }}, {{ 205 }, { 8 }}, {{ 45 }, { 8 }}, {{ 173 }, { 8 }}, {{ 109 }, { 8 }},
{{ 237 }, { 8 }}, {{ 29 }, { 8 }}, {{ 157 }, { 8 }}, {{ 93 }, { 8 }}, {{ 221 }, { 8 }},
{{ 61 }, { 8 }}, {{ 189 }, { 8 }}, {{ 125 }, { 8 }}, {{ 253 }, { 8 }}, {{ 19 }, { 9 }},
{{ 275 }, { 9 }}, {{ 147 }, { 9 }}, {{ 403 }, { 9 }}, {{ 83 }, { 9 }}, {{ 339 }, { 9 }},
{{ 211 }, { 9 }}, {{ 467 }, { 9 }}, {{ 51 }, { 9 }}, {{ 307 }, { 9 }}, {{ 179 }, { 9 }},
{{ 435 }, { 9 }}, {{ 115 }, { 9 }}, {{ 371 }, { 9 }}, {{ 243 }, { 9 }}, {{ 499 }, { 9 }},
{{ 11 }, { 9 }}, {{ 267 }, { 9 }}, {{ 139 }, { 9 }}, {{ 395 }, { 9 }}, {{ 75 }, { 9 }},
{{ 331 }, { 9 }}, {{ 203 }, { 9 }}, {{ 459 }, { 9 }}, {{ 43 }, { 9 }}, {{ 299 }, { 9 }},
{{ 171 }, { 9 }}, {{ 427 }, { 9 }}, {{ 107 }, { 9 }}, {{ 363 }, { 9 }}, {{ 235 }, { 9 }},
{{ 491 }, { 9 }}, {{ 27 }, { 9 }}, {{ 283 }, { 9 }}, {{ 155 }, { 9 }}, {{ 411 }, { 9 }},
{{ 91 }, { 9 }}, {{ 347 }, { 9 }}, {{ 219 }, { 9 }}, {{ 475 }, { 9 }}, {{ 59 }, { 9 }},
{{ 315 }, { 9 }}, {{ 187 }, { 9 }}, {{ 443 }, { 9 }}, {{ 123 }, { 9 }}, {{ 379 }, { 9 }},
{{ 251 }, { 9 }}, {{ 507 }, { 9 }}, {{ 7 }, { 9 }}, {{ 263 }, { 9 }}, {{ 135 }, { 9 }},
{{ 391 }, { 9 }}, {{ 71 }, { 9 }}, {{ 327 }, { 9 }}, {{ 199 }, { 9 }}, {{ 455 }, { 9 }},
{{ 39 }, { 9 }}, {{ 295 }, { 9 }}, {{ 167 }, { 9 }}, {{ 423 }, { 9 }}, {{ 103 }, { 9 }},
{{ 359 }, { 9 }}, {{ 231 }, { 9 }}, {{ 487 }, { 9 }}, {{ 23 }, { 9 }}, {{ 279 }, { 9 }},
{{ 151 }, { 9 }}, {{ 407 }, { 9 }}, {{ 87 }, { 9 }}, {{ 343 }, { 9 }}, {{ 215 }, { 9 }},
{{ 471 }, { 9 }}, {{ 55 }, { 9 }}, {{ 311 }, { 9 }}, {{ 183 }, { 9 }}, {{ 439 }, { 9 }},
{{ 119 }, { 9 }}, {{ 375 }, { 9 }}, {{ 247 }, { 9 }}, {{ 503 }, { 9 }}, {{ 15 }, { 9 }},
{{ 271 }, { 9 }}, {{ 143 }, { 9 }}, {{ 399 }, { 9 }}, {{ 79 }, { 9 }}, {{ 335 }, { 9 }},
{{ 207 }, { 9 }}, {{ 463 }, { 9 }}, {{ 47 }, { 9 }}, {{ 303 }, { 9 }}, {{ 175 }, { 9 }},
{{ 431 }, { 9 }}, {{ 111 }, { 9 }}, {{ 367 }, { 9 }}, {{ 239 }, { 9 }}, {{ 495 }, { 9 }},
{{ 31 }, { 9 }}, {{ 287 }, { 9 }}, {{ 159 }, { 9 }}, {{ 415 }, { 9 }}, {{ 95 }, { 9 }},
{{ 351 }, { 9 }}, {{ 223 }, { 9 }}, {{ 479 }, { 9 }}, {{ 63 }, { 9 }}, {{ 319 }, { 9 }},
{{ 191 }, { 9 }}, {{ 447 }, { 9 }}, {{ 127 }, { 9 }}, {{ 383 }, { 9 }}, {{ 255 }, { 9 }},
{{ 511 }, { 9 }}, {{ 0 }, { 7 }}, {{ 64 }, { 7 }}, {{ 32 }, { 7 }}, {{ 96 }, { 7 }},
{{ 16 }, { 7 }}, {{ 80 }, { 7 }}, {{ 48 }, { 7 }}, {{ 112 }, { 7 }}, {{ 8 }, { 7 }},
{{ 72 }, { 7 }}, {{ 40 }, { 7 }}, {{ 104 }, { 7 }}, {{ 24 }, { 7 }}, {{ 88 }, { 7 }},
{{ 56 }, { 7 }}, {{ 120 }, { 7 }}, {{ 4 }, { 7 }}, {{ 68 }, { 7 }}, {{ 36 }, { 7 }},
{{ 100 }, { 7 }}, {{ 20 }, { 7 }}, {{ 84 }, { 7 }}, {{ 52 }, { 7 }}, {{ 116 }, { 7 }},
{{ 3 }, { 8 }}, {{ 131 }, { 8 }}, {{ 67 }, { 8 }}, {{ 195 }, { 8 }}, {{ 35 }, { 8 }},
{{ 163 }, { 8 }}, {{ 99 }, { 8 }}, {{ 227 }, { 8 }}
};
// The static distance tree. (Actually a trivial tree since all codes use 5 bits.)
static const ct_data static_dtree[D_CODES] =
{
{{ 0 }, { 5 }}, {{ 16 }, { 5 }}, {{ 8 },{ 5 }}, {{ 24 },{ 5 }}, {{ 4 },{ 5 }},
{{ 20 }, { 5 }}, {{ 12 }, { 5 }}, {{ 28 },{ 5 }}, {{ 2 },{ 5 }}, {{ 18 },{ 5 }},
{{ 10 }, { 5 }}, {{ 26 }, { 5 }}, {{ 6 },{ 5 }}, {{ 22 },{ 5 }}, {{ 14 },{ 5 }},
{{ 30 }, { 5 }}, {{ 1 }, { 5 }}, {{ 17 },{ 5 }}, {{ 9 },{ 5 }}, {{ 25 },{ 5 }},
{{ 5 }, { 5 }}, {{ 21 }, { 5 }}, {{ 13 },{ 5 }}, {{ 29 },{ 5 }}, {{ 3 },{ 5 }},
{{ 19 }, { 5 }}, {{ 11 }, { 5 }}, {{ 27 },{ 5 }}, {{ 7 },{ 5 }}, {{ 23 },{ 5 }}
};
// Distance codes. The first 256 values correspond to the distances
// 3 .. 258, the last 256 values correspond to the top 8 bits of
// the 15 bit distances.
static const byte tr_dist_code[DIST_CODE_LEN] =
{
0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8,
8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 0, 0, 16, 17,
18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
};
// length code for each normalized match length (0 == MIN_MATCH)
static const byte tr_length_code[MAX_MATCH - MIN_MATCH + 1] =
{
0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28
};
// First normalized length for each code (0 = MIN_MATCH)
static const int base_length[LENGTH_CODES] =
{
0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
64, 80, 96, 112, 128, 160, 192, 224, 0
};
// First normalized distance for each code (0 = distance of 1)
static const int base_dist[D_CODES] =
{
0, 1, 2, 3, 4, 6, 8, 12, 16, 24,
32, 48, 64, 96, 128, 192, 256, 384, 512, 768,
1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384, 24576
};
// Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
// For deflate_fast() (levels <= 3) good is ignored and lazy has a different
// meaning.
static block_state deflate_stored(deflate_state *s, EFlush flush);
static block_state deflate_fast(deflate_state *s, EFlush flush);
static block_state deflate_slow(deflate_state *s, EFlush flush);
// Values for max_lazy_match, good_match and max_chain_length, depending on
// the desired pack level (0..9). The values given below have been tuned to
// exclude worst case performance for pathological files. Better values may be
// found for specific files.
static const config configuration_table[10] =
{
// good lazy nice chain
{ 0, 0, 0, 0, deflate_stored }, // store only
{ 4, 4, 8, 4, deflate_fast }, // maximum speed, no lazy matches
{ 4, 5, 16, 8, deflate_fast },
{ 4, 6, 32, 32, deflate_fast },
{ 4, 4, 16, 16, deflate_slow }, // lazy matches
{ 8, 16, 32, 32, deflate_slow },
{ 8, 16, 128, 128, deflate_slow },
{ 8, 32, 128, 256, deflate_slow },
{ 32, 128, 258, 1024, deflate_slow },
{ 32, 258, 258, 4096, deflate_slow } // maximum compression
};
// extra bits for each length code
static ulong extra_lbits[LENGTH_CODES] =
{
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
};
// Extra bits for distance codes
const ulong extra_dbits[D_CODES] =
{
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
};
// extra bits for each bit length code
static ulong extra_blbits[BL_CODES] =
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7
};
// The lengths of the bit length codes are sent in order of decreasing
// probability, to avoid transmitting the lengths for unused bit length codes.
static const byte bl_order[BL_CODES] =
{
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};
static static_tree_desc static_l_desc =
{
static_ltree, extra_lbits, LITERALS + 1, L_CODES, MAX_WBITS
};
static static_tree_desc static_d_desc =
{
static_dtree, extra_dbits, 0, D_CODES, MAX_WBITS
};
static static_tree_desc static_bl_desc =
{
NULL, extra_blbits, 0, BL_CODES, MAX_BL_BITS
};
// ===============================================================================
// Output bytes to the output stream. Inlined for speed
// ===============================================================================
inline void put_byte(deflate_state *s, const byte c)
{
s->pending_buf[s->pending++] = c;
}
// Fixme: write as 1 short
inline void put_short(deflate_state *s, const word w)
{
s->pending_buf[s->pending++] = (byte)(w & 0xff);
s->pending_buf[s->pending++] = (byte)(w >> 8);
}
inline void put_shortMSB(deflate_state *s, const word w)
{
s->pending_buf[s->pending++] = (byte)(w >> 8);
s->pending_buf[s->pending++] = (byte)(w & 0xff);
}
inline void put_longMSB(deflate_state *s, const ulong l)
{
s->pending_buf[s->pending++] = (byte)(l >> 24);
s->pending_buf[s->pending++] = (byte)(l >> 16);
s->pending_buf[s->pending++] = (byte)(l >> 8);
s->pending_buf[s->pending++] = (byte)(l & 0xff);
}
// ===============================================================================
// Send a value on a given number of bits.
// IN assertion: length <= 16 and value fits in length bits.
// ===============================================================================
static void send_bits(deflate_state *s, const ulong val, const ulong len)
{
assert(len <= 16);
assert(val <= 65536);
if(s->bi_valid > (BUF_SIZE - len))
{
s->bi_buf |= val << s->bi_valid;
put_short(s, s->bi_buf);
s->bi_buf = (word)(val >> (BUF_SIZE - s->bi_valid));
s->bi_valid += len - BUF_SIZE;
}
else
{
s->bi_buf |= val << s->bi_valid;
s->bi_valid += len;
}
}
// ===============================================================================
// Initialize a new block.
// ===============================================================================
static void init_block(deflate_state *s)
{
int n; // iterates over tree elements
// Initialize the trees.
for(n = 0; n < L_CODES; n++)
{
s->dyn_ltree[n].fc.freq = 0;
}
for(n = 0; n < D_CODES; n++)
{
s->dyn_dtree[n].fc.freq = 0;
}
for(n = 0; n < BL_CODES; n++)
{
s->bl_tree[n].fc.freq = 0;
}
s->dyn_ltree[END_BLOCK].fc.freq = 1;
s->opt_len = 0;
s->static_len = 0;
s->last_lit = 0;
s->matches = 0;
}
// ===============================================================================
// Initialize the tree data structures for a new zlib stream.
// ===============================================================================
static void tr_init(deflate_state *s)
{
s->l_desc.dyn_tree = s->dyn_ltree;
s->l_desc.stat_desc = &static_l_desc;
s->d_desc.dyn_tree = s->dyn_dtree;
s->d_desc.stat_desc = &static_d_desc;
s->bl_desc.dyn_tree = s->bl_tree;
s->bl_desc.stat_desc = &static_bl_desc;
s->bi_buf = 0;
s->bi_valid = 0;
// enough lookahead for inflate
s->last_eob_len = 8;
// Initialize the first block of the first file:
init_block(s);
}
// ===============================================================================
// Compares to subtrees, using the tree depth as tie breaker when
// the subtrees have equal frequency. This minimizes the worst case length.
// ===============================================================================
static bool smaller(ct_data *tree, ulong son, ulong daughter, byte *depth)
{
if(tree[son].fc.freq < tree[daughter].fc.freq)
{
return(true);
}
if((tree[son].fc.freq == tree[daughter].fc.freq) && (depth[son] <= depth[daughter]))
{
return(true);
}
return(false);
}
// ===============================================================================
// Restore the heap property by moving down the tree starting at node k,
// exchanging a node with the smallest of its two sons if necessary, stopping
// when the heap property is re-established (each father smaller than its
// two sons).
// ===============================================================================
static void pqdownheap(deflate_state *s, ct_data *tree, ulong node)
{
ulong base;
ulong sibling; // left son of node
base = s->heap[node];
sibling = node << 1;
while(sibling <= s->heap_len)
{
// Set sibling to the smallest of the two children
if((sibling < s->heap_len) && smaller(tree, s->heap[sibling + 1], s->heap[sibling], s->depth))
{
sibling++;
}
// Exit if base is smaller than both sons
if(smaller(tree, base, s->heap[sibling], s->depth))
{
break;
}
// Exchange base with the smallest son
s->heap[node] = s->heap[sibling];
node = sibling;
// And continue down the tree, setting sibling to the left son of base
sibling <<= 1;
}
s->heap[node] = base;
}
// ===============================================================================
// Compute the optimal bit lengths for a tree and update the total bit length
// for the current block.
// IN assertion: the fields freq and dad are set, heap[heap_max] and
// above are the tree nodes sorted by increasing frequency.
// OUT assertions: the field len is set to the optimal bit length, the
// array bl_count contains the frequencies for each bit length.
// The length opt_len is updated; static_len is also updated if stree is
// not null.
// ===============================================================================
static void gen_bitlen(deflate_state *s, tree_desc *desc)
{
const ct_data *stree;
const ulong *extra;
ulong base;
ulong max_length;
ulong heapIdx; // heap index
ulong n, m; // iterate over the tree elements
ulong bits; // bit length
ulong xbits; // extra bits
word freq; // frequency
ulong overflow; // number of elements with bit length too large
stree = desc->stat_desc->static_tree;
extra = desc->stat_desc->extra_bits;
base = desc->stat_desc->extra_base;
max_length = desc->stat_desc->max_length;
overflow = 0;
for(bits = 0; bits <= MAX_WBITS; bits++)
{
s->bl_count[bits] = 0;
}
// In a first pass, compute the optimal bit lengths (which may
// overflow in the case of the bit length tree).
// root of the heap
desc->dyn_tree[s->heap[s->heap_max]].dl.len = 0;
for(heapIdx = s->heap_max + 1; heapIdx < HEAP_SIZE; heapIdx++)
{
n = s->heap[heapIdx];
bits = desc->dyn_tree[desc->dyn_tree[n].dl.dad].dl.len + 1;
if(bits > max_length)
{
bits = max_length;
overflow++;
}
// We overwrite tree[n].dl.dad which is no longer needed
desc->dyn_tree[n].dl.len = (word)bits;
// not a leaf node
if(n > desc->max_code)
{
continue;
}
s->bl_count[bits]++;
xbits = 0;
if(n >= base)
{
xbits = extra[n - base];
}
freq = desc->dyn_tree[n].fc.freq;
s->opt_len += freq * (bits + xbits);
if(stree)
{
s->static_len += freq * (stree[n].dl.len + xbits);
}
}
if(!overflow)
{
return;
}
// Find the first bit length which could increase
do
{
bits = max_length - 1;
while(!s->bl_count[bits])
{
bits--;
}
// move one leaf down the tree
s->bl_count[bits]--;
// move one overflow item as its brother
s->bl_count[bits + 1] += 2;
// The brother of the overflow item also moves one step up,
// but this does not affect bl_count[max_length]
s->bl_count[max_length]--;
overflow -= 2;
}
while(overflow > 0);
// Now recompute all bit lengths, scanning in increasing frequency.
// heapIdx is still equal to HEAP_SIZE. (It is simpler to reconstruct all
// lengths instead of fixing only the wrong ones. This idea is taken
// from 'ar' written by Haruhiko Okumura.)
for(bits = max_length; bits; bits--)
{
n = s->bl_count[bits];
while(n)
{
m = s->heap[--heapIdx];
if(m > desc->max_code)
{
continue;
}
if(desc->dyn_tree[m].dl.len != bits)
{
s->opt_len += (bits - desc->dyn_tree[m].dl.len) * desc->dyn_tree[m].fc.freq;
desc->dyn_tree[m].dl.len = (word)bits;
}
n--;
}
}
}
// ===============================================================================
// Flush the bit buffer and align the output on a byte boundary
// ===============================================================================
static void bi_windup(deflate_state *s)
{
if(s->bi_valid > 8)
{
put_short(s, s->bi_buf);
}
else if(s->bi_valid > 0)
{
put_byte(s, (byte)s->bi_buf);
}
s->bi_buf = 0;
s->bi_valid = 0;
}
// ===============================================================================
// Reverse the first len bits of a code, using straightforward code (a faster
// method would use a table)
// ===============================================================================
static ulong bi_reverse(ulong code, ulong len)
{
ulong res;
assert(1 <= len);
assert(len <= 15);
res = 0;
do
{
res |= code & 1;
code >>= 1;
res <<= 1;
}
while(--len > 0);
return(res >> 1);
}
// ===============================================================================
// Generate the codes for a given tree and bit counts (which need not be optimal).
// IN assertion: the array bl_count contains the bit length statistics for
// the given tree and the field len is set for all tree elements.
// OUT assertion: the field code is set for all tree elements of non zero code length.
// ===============================================================================
static void gen_codes(ct_data *tree, ulong max_code, word *bl_count)
{
word next_code[MAX_WBITS + 1]; // next code value for each bit length
word code; // running code value
ulong bits; // bit index
ulong codes; // code index
ulong len;
// The distribution counts are first used to generate the code values
// without bit reversal.
code = 0;
for(bits = 1; bits <= MAX_WBITS; bits++)
{
code = (word)((code + bl_count[bits - 1]) << 1);
next_code[bits] = code;
}
// Check that the bit counts in bl_count are consistent. The last code
// must be all ones.
for(codes = 0; codes <= max_code; codes++)
{
len = tree[codes].dl.len;
if(!len)
{
continue;
}
// Now reverse the bits
tree[codes].fc.code = (word)bi_reverse(next_code[len]++, len);
}
}
// ===============================================================================
// Construct one Huffman tree and assigns the code bit strings and lengths.
// Update the total bit length for the current block.
// IN assertion: the field freq is set for all tree elements.
// OUT assertions: the fields len and code are set to the optimal bit length
// and corresponding code. The length opt_len is updated; static_len is
// also updated if stree is not null. The field max_code is set.
// ===============================================================================
static void build_tree(deflate_state *s, tree_desc *desc)
{
ct_data *tree;
const ct_data *stree;
ulong elems;
ulong n, m; // iterate over heap elements
ulong max_code; // largest code with non zero frequency
ulong node; // new node being created
tree = desc->dyn_tree;
stree = desc->stat_desc->static_tree;
elems = desc->stat_desc->elems;
max_code = 0;
// Construct the initial heap, with least frequent element in
// heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
// heap[0] is not used.
s->heap_len = 0;
s->heap_max = HEAP_SIZE;
for(n = 0; n < elems; n++)
{
if(tree[n].fc.freq)
{
max_code = n;
s->heap[++s->heap_len] = n;
s->depth[n] = 0;
}
else
{
tree[n].dl.len = 0;
}
}
// The pkzip format requires that at least one distance code exists,
// and that at least one bit should be sent even if there is only one
// possible code. So to avoid special checks later on we force at least
// two codes of non zero frequency.
while(s->heap_len < 2)
{
s->heap[++s->heap_len] = (max_code < 2 ? ++max_code : 0);
node = s->heap[s->heap_len];
tree[node].fc.freq = 1;
s->depth[node] = 0;
s->opt_len--;
if(stree)
{
s->static_len -= stree[node].dl.len;
}
// node is 0 or 1 so it does not have extra bits
}
desc->max_code = max_code;
// The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
// establish sub-heaps of increasing lengths:
for(n = s->heap_len >> 1; n >= 1; n--)
{
pqdownheap(s, tree, n);
}
// Construct the Huffman tree by repeatedly combining the least two
// frequent nodes.
// next internal node of the tree
node = elems;
do
{
n = s->heap[SMALLEST];
s->heap[SMALLEST] = s->heap[s->heap_len--];
pqdownheap(s, tree, SMALLEST);
m = s->heap[SMALLEST]; // m = node of next least frequency
s->heap[--s->heap_max] = n; // keep the nodes sorted by frequency
s->heap[--s->heap_max] = m;
// Create a new node father of n and m
tree[node].fc.freq = (word)(tree[n].fc.freq + tree[m].fc.freq);
if(s->depth[n] > s->depth[m])
{
s->depth[node] = s->depth[n];
}
else
{
s->depth[node] = s->depth[m];
s->depth[node]++;
}
tree[m].dl.dad = (word)node;
tree[n].dl.dad = (word)node;
// and insert the new node in the heap
s->heap[SMALLEST] = node++;
pqdownheap(s, tree, SMALLEST);
}
while(s->heap_len >= 2);
s->heap[--s->heap_max] = s->heap[SMALLEST];
// At this point, the fields freq and dad are set. We can now
// generate the bit lengths.
gen_bitlen(s, desc);
// The field len is now set, we can generate the bit codes
gen_codes (tree, max_code, s->bl_count);
}
// ===============================================================================
// Scan a literal or distance tree to determine the frequencies of the codes
// in the bit length tree.
// ===============================================================================
static void scan_tree (deflate_state *s, ct_data *tree, ulong max_code)
{
ulong n; // iterates over all tree elements
ulong prevlen; // last emitted length
ulong curlen; // length of current code
ulong nextlen; // length of next code
ulong count; // repeat count of the current code
ulong max_count; // max repeat count
ulong min_count; // min repeat count
prevlen = 0xffff;
nextlen = tree[0].dl.len;
count = 0;
max_count = 7;
min_count = 4;
if(!nextlen)
{
max_count = 138;
min_count = 3;
}
// guard
tree[max_code + 1].dl.len = (word)prevlen;
for(n = 0; n <= max_code; n++)
{
curlen = nextlen;
nextlen = tree[n + 1].dl.len;
if((++count < max_count) && (curlen == nextlen))
{
continue;
}
else if(count < min_count)
{
s->bl_tree[curlen].fc.freq += (word)count;
}
else if(curlen)
{
if(curlen != prevlen)
{
s->bl_tree[curlen].fc.freq++;
}
s->bl_tree[REP_3_6].fc.freq++;
}
else if(count <= 10)
{
s->bl_tree[REPZ_3_10].fc.freq++;
}
else
{
s->bl_tree[REPZ_11_138].fc.freq++;
}
count = 0;
prevlen = curlen;
if(!nextlen)
{
max_count = 138;
min_count = 3;
}
else if(curlen == nextlen)
{
max_count = 6;
min_count = 3;
}
else
{
max_count = 7;
min_count = 4;
}
}
}
// ===============================================================================
// Send a literal or distance tree in compressed form, using the codes in bl_tree.
// ===============================================================================
static void send_tree(deflate_state *s, ct_data *tree, ulong max_code)
{
ulong n; // iterates over all tree elements
ulong prevlen; // last emitted length
ulong curlen; // length of current code
ulong nextlen; // length of next code
ulong count; // repeat count of the current code
ulong max_count; // max repeat count
ulong min_count; // min repeat count
prevlen = 0xffff;
nextlen = tree[0].dl.len;
count = 0;
max_count = 7;
min_count = 4;
if(!nextlen)
{
max_count = 138;
min_count = 3;
}
for(n = 0; n <= max_code; n++)
{
curlen = nextlen;
nextlen = tree[n + 1].dl.len;
if((++count < max_count) && (curlen == nextlen))
{
continue;
}
else if(count < min_count)
{
do
{
send_bits(s, s->bl_tree[curlen].fc.code, s->bl_tree[curlen].dl.len);
}
while(--count);
}
else if(curlen)
{
if(curlen != prevlen)
{
send_bits(s, s->bl_tree[curlen].fc.code, s->bl_tree[curlen].dl.len);
count--;
}
send_bits(s, s->bl_tree[REP_3_6].fc.code, s->bl_tree[REP_3_6].dl.len);
send_bits(s, count - 3, 2);
}
else if(count <= 10)
{
send_bits(s, s->bl_tree[REPZ_3_10].fc.code, s->bl_tree[REPZ_3_10].dl.len);
send_bits(s, count - 3, 3);
}
else
{
send_bits(s, s->bl_tree[REPZ_11_138].fc.code, s->bl_tree[REPZ_11_138].dl.len);
send_bits(s, count - 11, 7);
}
count = 0;
prevlen = curlen;
if(!nextlen)
{
max_count = 138;
min_count = 3;
}
else if(curlen == nextlen)
{
max_count = 6;
min_count = 3;
}
else
{
max_count = 7;
min_count = 4;
}
}
}
// ===============================================================================
// Construct the Huffman tree for the bit lengths and return the index in
// bl_order of the last bit length code to send.
// ===============================================================================
static ulong build_bl_tree(deflate_state *s)
{
ulong max_blindex; // index of last bit length code of non zero freq
// Determine the bit length frequencies for literal and distance trees
scan_tree(s, s->dyn_ltree, s->l_desc.max_code);
scan_tree(s, s->dyn_dtree, s->d_desc.max_code);
// Build the bit length tree
build_tree(s, &s->bl_desc);
// opt_len now includes the length of the tree representations, except
// the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
// Determine the number of bit length codes to send. The pkzip format
// requires that at least 4 bit length codes be sent. (appnote.txt says
// 3 but the actual value used is 4.)
for(max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--)
{
if(s->bl_tree[bl_order[max_blindex]].dl.len)
{
break;
}
}
// Update opt_len to include the bit length tree and counts
s->opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
return(max_blindex);
}
// ===========================================================================
// Send the header for a block using dynamic Huffman trees: the counts, the
// lengths of the bit length codes, the literal tree and the distance tree.
// IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
// ===========================================================================
static void send_all_trees(deflate_state *s, ulong lcodes, ulong dcodes, ulong blcodes)
{
ulong rank; // index in bl_order
// not +255 as stated in appnote.txt
send_bits(s, lcodes - 257, 5);
send_bits(s, dcodes - 1, 5);
// not -3 as stated in appnote.txt
send_bits(s, blcodes - 4, 4);
for(rank = 0; rank < blcodes; rank++)
{
send_bits(s, s->bl_tree[bl_order[rank]].dl.len, 3);
}
// literal tree
send_tree(s, (ct_data *)s->dyn_ltree, lcodes - 1);
// distance tree
send_tree(s, (ct_data *)s->dyn_dtree, dcodes - 1);
}
// ===========================================================================
// Send the block data compressed using the given Huffman trees
// ===========================================================================
static void compress_block(deflate_state *s, const ct_data *ltree, const ct_data *dtree)
{
ulong dist; // distance of matched string
ulong lenCount; // match length or unmatched char (if dist == 0)
ulong lenIdx; // running index in l_buf
ulong code; // the code to send
ulong extra; // number of extra bits to send
lenIdx = 0;
if(s->last_lit)
{
do
{
dist = s->d_buf[lenIdx];
lenCount = s->l_buf[lenIdx++];
if(!dist)
{
// send a literal byte
send_bits(s, ltree[lenCount].fc.code, ltree[lenCount].dl.len);
}
else
{
// Here, lenCount is the match length - MIN_MATCH
code = tr_length_code[lenCount];
// send the length code
send_bits(s, ltree[code + LITERALS + 1].fc.code, ltree[code + LITERALS + 1].dl.len);
extra = extra_lbits[code];
if(extra)
{
lenCount -= base_length[code];
// send the extra length bits
send_bits(s, lenCount, extra);
}
// dist is now the match distance - 1
dist--;
code = (dist < 256 ? tr_dist_code[dist] : tr_dist_code[256 + (dist >> 7)]);
// send the distance code
send_bits(s, dtree[code].fc.code, dtree[code].dl.len);
extra = extra_dbits[code];
if(extra)
{
dist -= base_dist[code];
// send the extra distance bits
send_bits(s, dist, extra);
}
}
}
while(lenIdx < s->last_lit);
}
send_bits(s, ltree[END_BLOCK].fc.code, ltree[END_BLOCK].dl.len);
s->last_eob_len = ltree[END_BLOCK].dl.len;
}
// ===========================================================================
// Send a stored block
// ===========================================================================
static void tr_stored_block(deflate_state *s, const byte *buf, ulong stored_len, bool eof)
{
// send block type
send_bits(s, (STORED_BLOCK << 1) + (ulong)eof, 3);
// align on byte boundary
bi_windup(s);
// enough lookahead for inflate
s->last_eob_len = 8;
put_short(s, (word)stored_len);
put_short(s, (word)~stored_len);
while(stored_len--)
{
put_byte(s, *buf++);
}
}
// ===========================================================================
// Determine the best encoding for the current block: dynamic trees, static
// trees or store, and output the encoded block to the zip file.
// ===========================================================================
static void tr_flush_block(deflate_state *s, const byte *buf, ulong stored_len, bool eof)
{
ulong opt_lenb;
ulong static_lenb;
ulong max_blindex; // index of last bit length code of non zero freq
max_blindex = 0;
// Build the Huffman trees unless a stored block is forced
if(s->level > 0)
{
// Construct the literal and distance trees
build_tree(s, &s->l_desc);
build_tree(s, &s->d_desc);
// At this point, opt_len and static_len are the total bit lengths of
// the compressed block data, excluding the tree representations.
// Build the bit length tree for the above two trees, and get the index
// in bl_order of the last bit length code to send.
max_blindex = build_bl_tree(s);
// Determine the best encoding. Compute first the block length in bytes
opt_lenb = (s->opt_len + 3 + 7) >> 3;
static_lenb = (s->static_len + 3 + 7) >> 3;
if(static_lenb <= opt_lenb)
{
opt_lenb = static_lenb;
}
}
else
{
static_lenb = stored_len + 5;
// force a stored block
opt_lenb = static_lenb;
}
if(stored_len + 4 <= opt_lenb && buf)
{
// 4: two words for the lengths
// The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
// Otherwise we can't have processed more than WSIZE input bytes since
// the last block flush, because compression would have been
// successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
// transform a block into a stored block.
tr_stored_block(s, buf, stored_len, eof);
}
else if(static_lenb == opt_lenb)
{
send_bits(s, (STATIC_TREES << 1) + (ulong)eof, 3);
compress_block(s, static_ltree, static_dtree);
}
else
{
send_bits(s, (DYN_TREES << 1) + (ulong)eof, 3);
send_all_trees(s, s->l_desc.max_code + 1, s->d_desc.max_code + 1, max_blindex + 1);
compress_block(s, s->dyn_ltree, s->dyn_dtree);
}
// The above check is made mod 2^32, for files larger than 512 MB
// and uLong implemented on 32 bits.
init_block(s);
if(eof)
{
bi_windup(s);
}
}
// ===============================================================================
// ===============================================================================
inline bool tr_tally_lit(deflate_state *s, byte c)
{
s->d_buf[s->last_lit] = 0;
s->l_buf[s->last_lit++] = c;
s->dyn_ltree[c].fc.freq++;
return(s->last_lit == LIT_BUFSIZE - 1);
}
// ===============================================================================
// ===============================================================================
inline bool tr_tally_dist(deflate_state *s, ulong dist, ulong len)
{
assert(dist < 65536);
assert(len < 256);
dist &= 0xffff;
len &= 0xff;
s->d_buf[s->last_lit] = (word)dist;
s->l_buf[s->last_lit++] = (byte)len;
dist--;
s->dyn_ltree[tr_length_code[len] + LITERALS + 1].fc.freq++;
s->dyn_dtree[(dist < 256 ? tr_dist_code[dist] : tr_dist_code[256 + (dist >> 7)])].fc.freq++;
return(s->last_lit == LIT_BUFSIZE - 1);
}
// ===============================================================================
// Insert string str in the dictionary and set match_head to the previous head
// of the hash chain (the most recent string with same hash key). Return
// the previous length of the hash chain.
// If this file is compiled with -DFASTEST, the compression level is forced
// to 1, and no hash chains are maintained.
// IN assertion: all calls to to INSERT_STRING are made with consecutive
// input characters and the first MIN_MATCH bytes of str are valid
// (except for the last MIN_MATCH-1 bytes of the input file).
// ===============================================================================
inline void insert_string(deflate_state *s, ulong str, ulong &match_head)
{
s->ins_h = ((s->ins_h << HASH_SHIFT) ^ s->window[str + (MIN_MATCH - 1)]) & HASH_MASK;
match_head = s->head[s->ins_h];
s->prev[str & WINDOW_MASK] = s->head[s->ins_h];
s->head[s->ins_h] = (word)str;
}
// ===========================================================================
// Initialize the "longest match" routines for a new zlib stream
// ===========================================================================
static void lm_init(deflate_state *s)
{
s->head[HASH_SIZE - 1] = NULL;
memset(s->head, 0, (HASH_SIZE - 1) * sizeof(*s->head));
// Set the default configuration parameters:
s->max_lazy_match = configuration_table[s->level].max_lazy;
s->good_match = configuration_table[s->level].good_length;
s->nice_match = configuration_table[s->level].nice_length;
s->max_chain_length = configuration_table[s->level].max_chain;
s->strstart = 0;
s->block_start = 0;
s->lookahead = 0;
s->prev_length = MIN_MATCH - 1;
s->match_length = MIN_MATCH - 1;
s->match_available = 0;
s->ins_h = 0;
}
// ===========================================================================
// Set match_start to the longest match starting at the given string and
// return its length. Matches shorter or equal to prev_length are discarded,
// in which case the result is equal to prev_length and match_start is
// garbage.
// IN assertions: cur_match is the head of the hash chain for the current
// string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
// OUT assertion: the match length is not greater than s->lookahead.
// ===========================================================================
inline byte *qcmp(byte *scan, byte *match, ulong count)
{
byte *retval;
_asm
{
push esi
push edi
push ecx
mov esi, [scan]
mov edi, [match]
mov ecx, [count]
repe cmpsb
pop ecx
pop edi
mov [retval], esi
pop esi
}
return(--retval);
}
static ulong longest_match(deflate_state *s, ulong cur_match)
{
ulong chain_length; // max hash chain length
ulong limit;
byte *scan; // current string
byte *match; // matched string
ulong len; // length of current match
ulong best_len; // best match length so far
ulong nice_match; // stop if match long enough
byte scan_end1;
byte scan_end;
chain_length = s->max_chain_length;
scan = s->window + s->strstart;
best_len = s->prev_length;
nice_match = s->nice_match;
// Stop when cur_match becomes <= limit. To simplify the code,
// we prevent matches with the string of window index 0.
limit = s->strstart > (WINDOW_SIZE - MIN_LOOKAHEAD) ? s->strstart - (WINDOW_SIZE - MIN_LOOKAHEAD) : NULL;
scan_end1 = scan[best_len - 1];
scan_end = scan[best_len];
// Do not waste too much time if we already have a good match:
if(s->prev_length >= s->good_match)
{
chain_length >>= 2;
}
// Do not look for matches beyond the end of the input. This is necessary
// to make deflate deterministic.
if(nice_match > s->lookahead)
{
nice_match = s->lookahead;
}
do
{
match = s->window + cur_match;
// Skip to next match if the match length cannot increase
// or if the match length is less than 2:
if((match[best_len] != scan_end) || (match[best_len - 1] != scan_end1) || (match[0] != scan[0]) || (match[1] != scan[1]))
{
continue;
}
// The check at best_len-1 can be removed because it will be made
// again later. (This heuristic is not always a win.)
// It is not necessary to compare scan[2] and match[2] since they
// are always equal when the other bytes match, given that
// the hash keys are equal
scan = qcmp(scan + 3, match + 3, MAX_MATCH - 2);
len = scan - (s->window + s->strstart);
scan = s->window + s->strstart;
if(len > best_len)
{
s->match_start = cur_match;
best_len = len;
if(len >= nice_match)
{
break;
}
scan_end1 = scan[best_len - 1];
scan_end = scan[best_len];
}
} while((cur_match = s->prev[cur_match & WINDOW_MASK]) > limit && --chain_length);
if(best_len <= s->lookahead)
{
return(best_len);
}
return(s->lookahead);
}
// ===========================================================================
// Flush as much pending output as possible. All deflate() output goes
// through this function so some applications may wish to modify it
// to avoid allocating a large z->next_out buffer and copying into it.
// (See also read_buf()).
// ===========================================================================
static void flush_pending(z_stream *z)
{
ulong len = z->dstate->pending;
if(len > z->avail_out)
{
len = z->avail_out;
}
if(!len)
{
return;
}
assert(len <= MAX_BLOCK_SIZE + 5);
assert(z->dstate->pending_out + len <= z->dstate->pending_buf + MAX_BLOCK_SIZE + 5);
memcpy(z->next_out, z->dstate->pending_out, len);
z->next_out += len;
z->total_out += len;
z->dstate->pending_out += len;
z->avail_out -= len;
z->dstate->pending -= len;
if(!z->dstate->pending)
{
z->dstate->pending_out = z->dstate->pending_buf;
}
}
// ===========================================================================
// Read a new buffer from the current input stream, update the adler32
// and total number of bytes read. All deflate() input goes through
// this function so some applications may wish to modify it to avoid
// allocating a large z->next_in buffer and copying from it.
// (See also flush_pending()).
// ===========================================================================
static ulong read_buf(z_stream *z, byte *buf, ulong size)
{
ulong len;
len = z->avail_in;
if(len > size)
{
len = size;
}
if(!len)
{
return(0);
}
z->avail_in -= len;
if(!z->dstate->noheader)
{
z->dstate->adler = adler32(z->dstate->adler, z->next_in, len);
}
memcpy(buf, z->next_in, len);
z->next_in += len;
return(len);
}
// ===========================================================================
// Fill the window when the lookahead becomes insufficient.
// Updates strstart and lookahead.
//
// IN assertion: lookahead < MIN_LOOKAHEAD
// OUT assertions: strstart <= BIG_WINDOW_SIZE - MIN_LOOKAHEAD
// At least one byte has been read, or avail_in == 0; reads are
// performed for at least two bytes (required for the zip translate_eol
// option -- not supported here).
// ===========================================================================
static void fill_window(deflate_state *s)
{
ulong n, m;
word *p;
ulong more; // Amount of free space at the end of the window.
do
{
more = BIG_WINDOW_SIZE - s->lookahead - s->strstart;
if(s->strstart >= WINDOW_SIZE + (WINDOW_SIZE - MIN_LOOKAHEAD))
{
memcpy(s->window, s->window + WINDOW_SIZE, WINDOW_SIZE);
s->match_start -= WINDOW_SIZE;
// Make strstart >= MAX_DIST
s->strstart -= WINDOW_SIZE;
s->block_start -= WINDOW_SIZE;
// Slide the hash table (could be avoided with 32 bit values
// at the expense of memory usage). We slide even when level == 0
// to keep the hash table consistent if we switch back to level > 0
// later. (Using level 0 permanently is not an optimal usage of
// zlib, so we don't care about this pathological case.)
n = HASH_SIZE;
p = &s->head[n];
do
{
m = *--p;
*p = (word)(m >= WINDOW_SIZE ? m - WINDOW_SIZE : 0);
}
while(--n);
n = WINDOW_SIZE;
p = &s->prev[n];
do
{
m = *--p;
*p = (word)(m >= WINDOW_SIZE ? m - WINDOW_SIZE : 0);
// If n is not on any hash chain, prev[n] is garbage but
// its value will never be used.
}
while(--n);
more += WINDOW_SIZE;
}
if(!s->z->avail_in)
{
return;
}
// If there was no sliding:
// strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
// more == BIG_WINDOW_SIZE - lookahead - strstart
// => more >= BIG_WINDOW_SIZE - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
// => more >= BIG_WINDOW_SIZE- 2*WSIZE + 2
// If there was sliding, more >= WSIZE. So in all cases, more >= 2.
n = read_buf(s->z, s->window + s->strstart + s->lookahead, more);
s->lookahead += n;
// Initialize the hash value now that we have some input:
if(s->lookahead >= MIN_MATCH)
{
s->ins_h = ((s->window[s->strstart] << HASH_SHIFT) ^ s->window[s->strstart + 1]) & HASH_MASK;
}
// If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
// but this is not important since only literal bytes will be emitted.
}
while(s->lookahead < MIN_LOOKAHEAD && s->z->avail_in);
}
// ===========================================================================
// Flush the current block, with given end-of-file flag.
// IN assertion: strstart is set to the end of the current match.
// ===========================================================================
inline void flush_block_only(deflate_state *s, bool eof)
{
if(s->block_start >= 0)
{
tr_flush_block(s, &s->window[s->block_start], s->strstart - s->block_start, eof);
}
else
{
tr_flush_block(s, 0, s->strstart - s->block_start, eof);
}
s->block_start = s->strstart;
flush_pending(s->z);
}
// ===========================================================================
// Copy without compression as much as possible from the input stream, return
// the current block state.
// This function does not insert new strings in the dictionary since
// uncompressible data is probably not useful. This function is used
// only for the level=0 compression option.
// NOTE: this function should be optimized to avoid extra copying from
// window to pending_buf.
// ===========================================================================
static block_state deflate_stored(deflate_state *s, EFlush flush)
{
// Stored blocks are limited to 0xffff bytes, pending_buf is limited
// to pending_buf_size, and each stored block has a 5 byte header:
ulong max_start;
// Copy as much as possible from input to output:
while(true)
{
// Fill the window as much as possible
if(s->lookahead <= 1)
{
fill_window(s);
if(!s->lookahead && (flush == Z_NO_FLUSH))
{
return(NEED_MORE);
}
if(!s->lookahead)
{
// flush the current block
break;
}
}
s->strstart += s->lookahead;
s->lookahead = 0;
// Emit a stored block if pending_buf will be full
max_start = s->block_start + MAX_BLOCK_SIZE;
if(!s->strstart || (s->strstart >= max_start))
{
// strstart == 0 is possible when wraparound on 16-bit machine
s->lookahead = s->strstart - max_start;
s->strstart = max_start;
flush_block_only(s, false);
if(!s->z->avail_out)
{
return(NEED_MORE);
}
}
// Flush if we may have to slide, otherwise block_start may become
// negative and the data will be gone:
if(s->strstart - s->block_start >= WINDOW_SIZE - MIN_LOOKAHEAD)
{
flush_block_only(s, false);
if(!s->z->avail_out)
{
return(NEED_MORE);
}
}
}
flush_block_only(s, flush == Z_FINISH);
if(!s->z->avail_out)
{
return((flush == Z_FINISH) ? FINISH_STARTED : NEED_MORE);
}
return(flush == Z_FINISH ? FINISH_DONE : BLOCK_DONE);
}
// ===========================================================================
// Compress as much as possible from the input stream, return the current block state.
// This function does not perform lazy evaluation of matches and inserts
// new strings in the dictionary only for unmatched strings or for short
// matches. It is used only for the fast compression options.
// ===========================================================================
static block_state deflate_fast(deflate_state *s, EFlush flush)
{
ulong hash_head; // head of the hash chain
bool bflush; // set if current block must be flushed
hash_head = 0;
while(true)
{
// Make sure that we always have enough lookahead, except
// at the end of the input file. We need MAX_MATCH bytes
// for the next match, plus MIN_MATCH bytes to insert the
// string following the next match.
if(s->lookahead < MIN_LOOKAHEAD)
{
fill_window(s);
if((s->lookahead < MIN_LOOKAHEAD) && (flush == Z_NO_FLUSH))
{
return(NEED_MORE);
}
if(!s->lookahead)
{
// flush the current block
break;
}
}
// Insert the string window[strstart .. strstart+2] in the
// dictionary, and set hash_head to the head of the hash chain:
if(s->lookahead >= MIN_MATCH)
{
insert_string(s, s->strstart, hash_head);
}
// Find the longest match, discarding those <= prev_length.
// At this point we have always match_length < MIN_MATCH
if(hash_head && (s->strstart - hash_head <= WINDOW_SIZE - MIN_LOOKAHEAD))
{
// To simplify the code, we prevent matches with the string
// of window index 0 (in particular we have to avoid a match
// of the string with itself at the start of the input file).
s->match_length = longest_match(s, hash_head);
// longest_match() sets match_start
}
if(s->match_length >= MIN_MATCH)
{
s->z->quality++;
bflush = tr_tally_dist(s, s->strstart - s->match_start, s->match_length - MIN_MATCH);
s->lookahead -= s->match_length;
// Insert new strings in the hash table only if the match length
// is not too large. This saves time but degrades compression.
if((s->match_length <= s->max_lazy_match) && (s->lookahead >= MIN_MATCH))
{
// string at strstart already in hash table
s->match_length--;
do
{
// strstart never exceeds WSIZE-MAX_MATCH, so there are
// always MIN_MATCH bytes ahead.
s->strstart++;
insert_string(s, s->strstart, hash_head);
}
while(--s->match_length);
s->strstart++;
}
else
{
s->z->quality++;
s->strstart += s->match_length;
s->match_length = 0;
s->ins_h = ((s->window[s->strstart] << HASH_SHIFT) ^ s->window[s->strstart + 1]) & HASH_MASK;
// If lookahead < MIN_MATCH, ins_h is garbage, but it does not
// matter since it will be recomputed at next deflate call.
}
}
else
{
// No match, output a literal byte
bflush = tr_tally_lit(s, s->window[s->strstart]);
s->lookahead--;
s->strstart++;
}
if(bflush)
{
flush_block_only(s, false);
if(!s->z->avail_out)
{
return(NEED_MORE);
}
}
}
flush_block_only(s, flush == Z_FINISH);
if(!s->z->avail_out)
{
return(flush == Z_FINISH ? FINISH_STARTED : NEED_MORE);
}
return(flush == Z_FINISH ? FINISH_DONE : BLOCK_DONE);
}
// ===========================================================================
// Same as above, but achieves better compression. We use a lazy
// evaluation for matches: a match is finally adopted only if there is
// no better match at the next window position.
// ===========================================================================
static block_state deflate_slow(deflate_state *s, EFlush flush)
{
ulong hash_head; // head of hash chain
ulong max_insert;
bool bflush; // set if current block must be flushed
hash_head = 0;
// Process the input block.
while(true)
{
// Make sure that we always have enough lookahead, except
// at the end of the input file. We need MAX_MATCH bytes
// for the next match, plus MIN_MATCH bytes to insert the
// string following the next match.
if(s->lookahead < MIN_LOOKAHEAD)
{
fill_window(s);
if((s->lookahead < MIN_LOOKAHEAD) && (flush == Z_NO_FLUSH))
{
return(NEED_MORE);
}
if(!s->lookahead)
{
// flush the current block
break;
}
}
// Insert the string window[strstart .. strstart+2] in the
// dictionary, and set hash_head to the head of the hash chain:
if(s->lookahead >= MIN_MATCH)
{
insert_string(s, s->strstart, hash_head);
}
// Find the longest match, discarding those <= prev_length.
s->prev_length = s->match_length;
s->prev_match = s->match_start;
s->match_length = MIN_MATCH - 1;
if(hash_head && (s->prev_length < s->max_lazy_match) && (s->strstart - hash_head <= WINDOW_SIZE - MIN_LOOKAHEAD))
{
// To simplify the code, we prevent matches with the string
// of window index 0 (in particular we have to avoid a match
// of the string with itself at the start of the input file).
// longest_match() sets match_start
s->match_length = longest_match(s, hash_head);
if((s->match_length <= 5) && ((s->match_length == MIN_MATCH) && (s->strstart - s->match_start > TOO_FAR)))
{
// If prev_match is also MIN_MATCH, match_start is garbage
// but we will ignore the current match anyway.
s->match_length = MIN_MATCH - 1;
}
}
// If there was a match at the previous step and the current
// match is not better, output the previous match:
if((s->prev_length >= MIN_MATCH) && (s->match_length <= s->prev_length))
{
// Do not insert strings in hash table beyond this.
max_insert = s->strstart + s->lookahead - MIN_MATCH;
bflush = tr_tally_dist(s, s->strstart - 1 - s->prev_match, s->prev_length - MIN_MATCH);
// Insert in hash table all strings up to the end of the match.
// strstart-1 and strstart are already inserted. If there is not
// enough lookahead, the last two strings are not inserted in
// the hash table.
s->lookahead -= s->prev_length - 1;
s->prev_length -= 2;
do
{
if(++s->strstart <= max_insert)
{
insert_string(s, s->strstart, hash_head);
}
}
while(--s->prev_length);
s->match_available = 0;
s->match_length = MIN_MATCH - 1;
s->strstart++;
if(bflush)
{
flush_block_only(s, false);
if(!s->z->avail_out)
{
return(NEED_MORE);
}
}
}
else if(s->match_available)
{
// If there was no match at the previous position, output a
// single literal. If there was a match but the current match
// is longer, truncate the previous match to a single literal.
bflush = tr_tally_lit(s, s->window[s->strstart - 1]);
if(bflush)
{
flush_block_only(s, false);
}
s->strstart++;
s->lookahead--;
if(!s->z->avail_out)
{
return(NEED_MORE);
}
}
else
{
// There is no previous match to compare with, wait for
// the next step to decide.
s->match_available = 1;
s->strstart++;
s->lookahead--;
}
}
if(s->match_available)
{
bflush = tr_tally_lit(s, s->window[s->strstart - 1]);
s->match_available = 0;
}
flush_block_only(s, flush == Z_FINISH);
if(!s->z->avail_out)
{
return(flush == Z_FINISH ? FINISH_STARTED : NEED_MORE);
}
return(flush == Z_FINISH ? FINISH_DONE : BLOCK_DONE);
}
// -------------------------------------------------------------------------------------------------
// Controlling routines
// -------------------------------------------------------------------------------------------------
EStatus deflateInit(z_stream *z, ELevel level, int noWrap)
{
deflate_state *s;
assert(z);
deflate_error = "OK";
if((level < Z_STORE_COMPRESSION) || (level > Z_MAX_COMPRESSION))
{
deflate_error = "Invalid compression level";
return(Z_STREAM_ERROR);
}
s = (deflate_state *)Z_Malloc(sizeof(deflate_state), TAG_DEFLATE, qtrue);
z->dstate = (deflate_state *)s;
s->z = z;
// undocumented feature: suppress zlib header
s->noheader = noWrap;
s->level = level;
z->total_out = 0;
z->quality = 0;
s->pending = 0;
s->pending_out = s->pending_buf;
s->status = s->noheader ? BUSY_STATE : INIT_STATE;
s->adler = 1;
s->last_flush = Z_NO_FLUSH;
tr_init(s);
lm_init(s);
return(Z_OK);
}
// ===========================================================================
// Copy the source state to the destination state.
// To simplify the source, this is not supported for 16-bit MSDOS (which
// doesn't have enough memory anyway to duplicate compression states).
// ===========================================================================
EStatus deflateCopy(z_stream *dest, z_stream *source)
{
deflate_state *ds;
deflate_state *ss;
assert(source);
assert(dest);
assert(source->dstate);
assert(!dest->dstate);
*dest = *source;
ss = source->dstate;
ds = (deflate_state *)Z_Malloc(sizeof(deflate_state), TAG_DEFLATE, qtrue);
dest->dstate = ds;
*ds = *ss;
ds->z = dest;
ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
ds->l_desc.dyn_tree = ds->dyn_ltree;
ds->d_desc.dyn_tree = ds->dyn_dtree;
ds->bl_desc.dyn_tree = ds->bl_tree;
return(Z_OK);
}
// ===========================================================================
// ===========================================================================
EStatus deflate(z_stream *z, EFlush flush)
{
EFlush old_flush; // value of flush param for previous deflate call
deflate_state *s;
ulong header;
ulong level_flags;
assert(z);
assert(z->dstate);
if((flush > Z_FINISH) || (flush < Z_NO_FLUSH))
{
deflate_error = "Invalid flush type";
return(Z_STREAM_ERROR);
}
s = z->dstate;
if(!z->next_out || (!z->next_in && z->avail_in) || (s->status == FINISH_STATE && flush != Z_FINISH))
{
deflate_error = "Invalid output data";
return (Z_STREAM_ERROR);
}
if(!z->avail_out)
{
deflate_error = "No output space";
return (Z_BUF_ERROR);
}
old_flush = s->last_flush;
s->last_flush = flush;
// Write the zlib header
if(s->status == INIT_STATE)
{
header = (ZF_DEFLATED + ((MAX_WBITS - 8) << 4)) << 8;
level_flags = (s->level - 1) >> 1;
if(level_flags > 3)
{
level_flags = 3;
}
header |= (level_flags << 6);
header += 31 - (header % 31);
s->status = BUSY_STATE;
put_shortMSB(s, (word)header);
s->adler = 1;
}
// Flush as much pending output as possible
if(s->pending)
{
flush_pending(z);
if(!z->avail_out)
{
// Since avail_out is 0, deflate will be called again with
// more output space, but possibly with both pending and
// avail_in equal to zero. There won't be anything to do,
// but this is not an error situation so make sure we
// return OK instead of BUF_ERROR at next call of deflate:
s->last_flush = Z_NEED_MORE;
return(Z_OK);
}
// Make sure there is something to do and avoid duplicate consecutive
// flushes. For repeated and useless calls with Z_FINISH, we keep
// returning Z_STREAM_END instead of Z_BUFF_ERROR.
}
else if(!z->avail_in && (flush <= old_flush) && (flush != Z_FINISH))
{
deflate_error = "No available input";
return(Z_BUF_ERROR);
}
// User must not provide more input after the first FINISH
if((s->status == FINISH_STATE) && z->avail_in)
{
deflate_error = "Trying to finish while input available";
return(Z_BUF_ERROR);
}
// Start a new block or continue the current one.
if(z->avail_in || s->lookahead || ((flush != Z_NO_FLUSH) && (s->status != FINISH_STATE)))
{
block_state bstate;
bstate = (*(configuration_table[s->level].func))(s, flush);
if((bstate == FINISH_STARTED) || (bstate == FINISH_DONE))
{
s->status = FINISH_STATE;
}
if((bstate == NEED_MORE) || (bstate == FINISH_STARTED))
{
if(!z->avail_out)
{
// avoid BUF_ERROR next call, see above
s->last_flush = Z_NEED_MORE;
}
return(Z_OK);
// If flush != Z_NO_FLUSH && avail_out == 0, the next call
// of deflate should use the same flush parameter to make sure
// that the flush is complete. So we don't have to output an
// empty block here, this will be done at next call. This also
// ensures that for a very small output buffer, we emit at most
// one empty block.
}
if(bstate == BLOCK_DONE)
{
// FULL_FLUSH or SYNC_FLUSH
tr_stored_block(s, NULL, 0, false);
flush_pending(z);
if(!z->avail_out)
{
// avoid BUF_ERROR at next call, see above
s->last_flush = Z_NEED_MORE;
return(Z_OK);
}
}
}
if(flush != Z_FINISH)
{
return(Z_OK);
}
if(s->noheader)
{
return(Z_STREAM_END);
}
// Write the zlib trailer (adler32)
put_longMSB(s, s->adler);
flush_pending(z);
// If avail_out is zero, the application will call deflate again
// to flush the rest. Write the trailer only once!
s->noheader = -1;
return(!!s->pending ? Z_OK : Z_STREAM_END);
}
// ===========================================================================
// ===========================================================================
EStatus deflateEnd(z_stream *z)
{
int status;
assert(z);
assert(z->dstate);
status = z->dstate->status;
if((status != INIT_STATE) && (status != BUSY_STATE) && (status != FINISH_STATE))
{
deflate_error = "Invalid state while ending";
return(Z_STREAM_ERROR);
}
Z_Free(z->dstate);
z->dstate = NULL;
if(status == BUSY_STATE)
{
deflate_error = "Ending while in busy state";
return(Z_DATA_ERROR);
}
return(Z_OK);
}
// ===========================================================================
// ===========================================================================
const char *deflateError(void)
{
return(deflate_error);
}
// ===============================================================================
// External calls
// ===============================================================================
bool DeflateFile(byte *src, ulong uncompressedSize, byte *dst, ulong maxCompressedSize, ulong *compressedSize, ELevel level, int noWrap)
{
z_stream z = { 0 };
if(deflateInit(&z, level, noWrap) != Z_OK)
{
return(false);
}
z.next_in = src;
z.avail_in = uncompressedSize;
z.next_out = dst;
z.avail_out = maxCompressedSize;
#ifdef _TIMING
int temp = timeGetTime();
#endif
if(deflate(&z, Z_FINISH) != Z_STREAM_END)
{
deflateEnd(&z);
return(false);
}
#ifdef _TIMING
totalDeflateTime[level] += timeGetTime() - temp;
totalDeflateCount[level]++;
#endif
if(deflateEnd(&z) != Z_OK)
{
return(false);
}
*compressedSize = z.total_out;
return(true);
}
// end
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