1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/ossrv/compressionlibs/ziplib/src/zlib/deflate.h Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,339 @@
1.4 +/* Portions Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
1.5 + * All rights reserved.
1.6 + */
1.7 +
1.8 +/* deflate.h -- internal compression state
1.9 + * Copyright (C) 1995-2004 Jean-loup Gailly
1.10 + * For conditions of distribution and use, see copyright notice in zlib.h
1.11 + */
1.12 +
1.13 +/* WARNING: this file should *not* be used by applications. It is
1.14 + part of the implementation of the compression library and is
1.15 + subject to change. Applications should only use zlib.h.
1.16 + */
1.17 +
1.18 +/* @(#) $Id$ */
1.19 +
1.20 +#ifndef DEFLATE_H
1.21 +#define DEFLATE_H
1.22 +
1.23 +#include "zutil.h"
1.24 +
1.25 +/* define NO_GZIP when compiling if you want to disable gzip header and
1.26 + trailer creation by deflate(). NO_GZIP would be used to avoid linking in
1.27 + the crc code when it is not needed. For shared libraries, gzip encoding
1.28 + should be left enabled. */
1.29 +#ifndef NO_GZIP
1.30 +# define GZIP
1.31 +#endif
1.32 +
1.33 +/* ===========================================================================
1.34 + * Internal compression state.
1.35 + */
1.36 +
1.37 +#define LENGTH_CODES 29
1.38 +/* number of length codes, not counting the special END_BLOCK code */
1.39 +
1.40 +#define LITERALS 256
1.41 +/* number of literal bytes 0..255 */
1.42 +
1.43 +#define L_CODES (LITERALS+1+LENGTH_CODES)
1.44 +/* number of Literal or Length codes, including the END_BLOCK code */
1.45 +
1.46 +#define D_CODES 30
1.47 +/* number of distance codes */
1.48 +
1.49 +#define BL_CODES 19
1.50 +/* number of codes used to transfer the bit lengths */
1.51 +
1.52 +#define HEAP_SIZE (2*L_CODES+1)
1.53 +/* maximum heap size */
1.54 +
1.55 +#define MAX_BITS 15
1.56 +/* All codes must not exceed MAX_BITS bits */
1.57 +
1.58 +#define INIT_STATE 42
1.59 +#define EXTRA_STATE 69
1.60 +#define NAME_STATE 73
1.61 +#define COMMENT_STATE 91
1.62 +#define HCRC_STATE 103
1.63 +#define BUSY_STATE 113
1.64 +#define FINISH_STATE 666
1.65 +/* Stream status */
1.66 +
1.67 +
1.68 +/* Data structure describing a single value and its code string. */
1.69 +typedef struct ct_data_s {
1.70 + union {
1.71 + ush freq; /* frequency count */
1.72 + ush code; /* bit string */
1.73 + } fc;
1.74 + union {
1.75 + ush dad; /* father node in Huffman tree */
1.76 + ush len; /* length of bit string */
1.77 + } dl;
1.78 +} FAR ct_data;
1.79 +
1.80 +#define Freq fc.freq
1.81 +#define Code fc.code
1.82 +#define Dad dl.dad
1.83 +#define Len dl.len
1.84 +
1.85 +typedef struct static_tree_desc_s static_tree_desc;
1.86 +
1.87 +typedef struct tree_desc_s {
1.88 + ct_data *dyn_tree; /* the dynamic tree */
1.89 + int max_code; /* largest code with non zero frequency */
1.90 +#ifdef SYMBIAN_EZLIB_DEVICE
1.91 + const static_tree_desc *stat_desc; /* the corresponding static tree */
1.92 +#else
1.93 + static_tree_desc *stat_desc; /* the corresponding static tree */
1.94 +#endif //SYMBIAN_EZLIB_DEVICE
1.95 +} FAR tree_desc;
1.96 +
1.97 +typedef ush Pos;
1.98 +typedef Pos FAR Posf;
1.99 +typedef unsigned IPos;
1.100 +
1.101 +/* A Pos is an index in the character window. We use short instead of int to
1.102 + * save space in the various tables. IPos is used only for parameter passing.
1.103 + */
1.104 +
1.105 +typedef struct internal_state {
1.106 + z_streamp strm; /* pointer back to this zlib stream */
1.107 + int status; /* as the name implies */
1.108 + Bytef *pending_buf; /* output still pending */
1.109 + ulg pending_buf_size; /* size of pending_buf */
1.110 + Bytef *pending_out; /* next pending byte to output to the stream */
1.111 + uInt pending; /* nb of bytes in the pending buffer */
1.112 + int wrap; /* bit 0 true for zlib, bit 1 true for gzip */
1.113 + gz_headerp gzhead; /* gzip header information to write */
1.114 + uInt gzindex; /* where in extra, name, or comment */
1.115 + Byte method; /* STORED (for zip only) or DEFLATED */
1.116 + int last_flush; /* value of flush param for previous deflate call */
1.117 +
1.118 + /* used by deflate.c: */
1.119 +
1.120 + uInt w_size; /* LZ77 window size (32K by default) */
1.121 + uInt w_bits; /* log2(w_size) (8..16) */
1.122 + uInt w_mask; /* w_size - 1 */
1.123 +
1.124 + Bytef *window;
1.125 + /* Sliding window. Input bytes are read into the second half of the window,
1.126 + * and move to the first half later to keep a dictionary of at least wSize
1.127 + * bytes. With this organization, matches are limited to a distance of
1.128 + * wSize-MAX_MATCH bytes, but this ensures that IO is always
1.129 + * performed with a length multiple of the block size. Also, it limits
1.130 + * the window size to 64K, which is quite useful on MSDOS.
1.131 + * To do: use the user input buffer as sliding window.
1.132 + */
1.133 +
1.134 + ulg window_size;
1.135 + /* Actual size of window: 2*wSize, except when the user input buffer
1.136 + * is directly used as sliding window.
1.137 + */
1.138 +
1.139 + Posf *prev;
1.140 + /* Link to older string with same hash index. To limit the size of this
1.141 + * array to 64K, this link is maintained only for the last 32K strings.
1.142 + * An index in this array is thus a window index modulo 32K.
1.143 + */
1.144 +
1.145 + Posf *head; /* Heads of the hash chains or NIL. */
1.146 +
1.147 + uInt ins_h; /* hash index of string to be inserted */
1.148 + uInt hash_size; /* number of elements in hash table */
1.149 + uInt hash_bits; /* log2(hash_size) */
1.150 + uInt hash_mask; /* hash_size-1 */
1.151 +
1.152 + uInt hash_shift;
1.153 + /* Number of bits by which ins_h must be shifted at each input
1.154 + * step. It must be such that after MIN_MATCH steps, the oldest
1.155 + * byte no longer takes part in the hash key, that is:
1.156 + * hash_shift * MIN_MATCH >= hash_bits
1.157 + */
1.158 +
1.159 + long block_start;
1.160 + /* Window position at the beginning of the current output block. Gets
1.161 + * negative when the window is moved backwards.
1.162 + */
1.163 +
1.164 + uInt match_length; /* length of best match */
1.165 + IPos prev_match; /* previous match */
1.166 + int match_available; /* set if previous match exists */
1.167 + uInt strstart; /* start of string to insert */
1.168 + uInt match_start; /* start of matching string */
1.169 + uInt lookahead; /* number of valid bytes ahead in window */
1.170 +
1.171 + uInt prev_length;
1.172 + /* Length of the best match at previous step. Matches not greater than this
1.173 + * are discarded. This is used in the lazy match evaluation.
1.174 + */
1.175 +
1.176 + uInt max_chain_length;
1.177 + /* To speed up deflation, hash chains are never searched beyond this
1.178 + * length. A higher limit improves compression ratio but degrades the
1.179 + * speed.
1.180 + */
1.181 +
1.182 + uInt max_lazy_match;
1.183 + /* Attempt to find a better match only when the current match is strictly
1.184 + * smaller than this value. This mechanism is used only for compression
1.185 + * levels >= 4.
1.186 + */
1.187 +# define max_insert_length max_lazy_match
1.188 + /* Insert new strings in the hash table only if the match length is not
1.189 + * greater than this length. This saves time but degrades compression.
1.190 + * max_insert_length is used only for compression levels <= 3.
1.191 + */
1.192 +
1.193 + int level; /* compression level (1..9) */
1.194 + int strategy; /* favor or force Huffman coding*/
1.195 +
1.196 + uInt good_match;
1.197 + /* Use a faster search when the previous match is longer than this */
1.198 +
1.199 + int nice_match; /* Stop searching when current match exceeds this */
1.200 +
1.201 + /* used by trees.c: */
1.202 + /* Didn't use ct_data typedef below to supress compiler warning */
1.203 + struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
1.204 + struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
1.205 + struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
1.206 +
1.207 + struct tree_desc_s l_desc; /* desc. for literal tree */
1.208 + struct tree_desc_s d_desc; /* desc. for distance tree */
1.209 + struct tree_desc_s bl_desc; /* desc. for bit length tree */
1.210 +
1.211 + ush bl_count[MAX_BITS+1];
1.212 + /* number of codes at each bit length for an optimal tree */
1.213 +
1.214 + int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
1.215 + int heap_len; /* number of elements in the heap */
1.216 + int heap_max; /* element of largest frequency */
1.217 + /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
1.218 + * The same heap array is used to build all trees.
1.219 + */
1.220 +
1.221 + uch depth[2*L_CODES+1];
1.222 + /* Depth of each subtree used as tie breaker for trees of equal frequency
1.223 + */
1.224 +
1.225 + uchf *l_buf; /* buffer for literals or lengths */
1.226 +
1.227 + uInt lit_bufsize;
1.228 + /* Size of match buffer for literals/lengths. There are 4 reasons for
1.229 + * limiting lit_bufsize to 64K:
1.230 + * - frequencies can be kept in 16 bit counters
1.231 + * - if compression is not successful for the first block, all input
1.232 + * data is still in the window so we can still emit a stored block even
1.233 + * when input comes from standard input. (This can also be done for
1.234 + * all blocks if lit_bufsize is not greater than 32K.)
1.235 + * - if compression is not successful for a file smaller than 64K, we can
1.236 + * even emit a stored file instead of a stored block (saving 5 bytes).
1.237 + * This is applicable only for zip (not gzip or zlib).
1.238 + * - creating new Huffman trees less frequently may not provide fast
1.239 + * adaptation to changes in the input data statistics. (Take for
1.240 + * example a binary file with poorly compressible code followed by
1.241 + * a highly compressible string table.) Smaller buffer sizes give
1.242 + * fast adaptation but have of course the overhead of transmitting
1.243 + * trees more frequently.
1.244 + * - I can't count above 4
1.245 + */
1.246 +
1.247 + uInt last_lit; /* running index in l_buf */
1.248 +
1.249 + ushf *d_buf;
1.250 + /* Buffer for distances. To simplify the code, d_buf and l_buf have
1.251 + * the same number of elements. To use different lengths, an extra flag
1.252 + * array would be necessary.
1.253 + */
1.254 +
1.255 + ulg opt_len; /* bit length of current block with optimal trees */
1.256 + ulg static_len; /* bit length of current block with static trees */
1.257 + uInt matches; /* number of string matches in current block */
1.258 + int last_eob_len; /* bit length of EOB code for last block */
1.259 +
1.260 +#ifdef DEBUG
1.261 + ulg compressed_len; /* total bit length of compressed file mod 2^32 */
1.262 + ulg bits_sent; /* bit length of compressed data sent mod 2^32 */
1.263 +#endif
1.264 +
1.265 + ush bi_buf;
1.266 + /* Output buffer. bits are inserted starting at the bottom (least
1.267 + * significant bits).
1.268 + */
1.269 + int bi_valid;
1.270 + /* Number of valid bits in bi_buf. All bits above the last valid bit
1.271 + * are always zero.
1.272 + */
1.273 +
1.274 +} FAR deflate_state;
1.275 +
1.276 +/* Output a byte on the stream.
1.277 + * IN assertion: there is enough room in pending_buf.
1.278 + */
1.279 +#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
1.280 +
1.281 +
1.282 +#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
1.283 +/* Minimum amount of lookahead, except at the end of the input file.
1.284 + * See deflate.c for comments about the MIN_MATCH+1.
1.285 + */
1.286 +
1.287 +#define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
1.288 +/* In order to simplify the code, particularly on 16 bit machines, match
1.289 + * distances are limited to MAX_DIST instead of WSIZE.
1.290 + */
1.291 +
1.292 + /* in trees.c */
1.293 +void _tr_init OF((deflate_state *s));
1.294 +int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
1.295 +void _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
1.296 + int eof));
1.297 +void _tr_align OF((deflate_state *s));
1.298 +void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
1.299 + int eof));
1.300 +
1.301 +#define d_code(dist) \
1.302 + ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
1.303 +/* Mapping from a distance to a distance code. dist is the distance - 1 and
1.304 + * must not have side effects. _dist_code[256] and _dist_code[257] are never
1.305 + * used.
1.306 + */
1.307 +
1.308 +#ifndef DEBUG
1.309 +/* Inline versions of _tr_tally for speed: */
1.310 +
1.311 +#if defined(GEN_TREES_H) || !defined(STDC)
1.312 + extern uch _length_code[];
1.313 + extern uch _dist_code[];
1.314 +#else
1.315 + extern const uch _length_code[];
1.316 + extern const uch _dist_code[];
1.317 +#endif
1.318 +
1.319 +# define _tr_tally_lit(s, c, flush) \
1.320 + { uch cc = (c); \
1.321 + s->d_buf[s->last_lit] = 0; \
1.322 + s->l_buf[s->last_lit++] = cc; \
1.323 + s->dyn_ltree[cc].Freq++; \
1.324 + flush = (s->last_lit == s->lit_bufsize-1); \
1.325 + }
1.326 +# define _tr_tally_dist(s, distance, length, flush) \
1.327 + { uch len = (uch)(length); /* suspect downcast from uInt to uch */\
1.328 + ush dist = (ush)(distance); /* suspect downcast from uInt to ush */\
1.329 + s->d_buf[s->last_lit] = dist; \
1.330 + s->l_buf[s->last_lit++] = len; \
1.331 + dist--; \
1.332 + s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
1.333 + s->dyn_dtree[d_code(dist)].Freq++; \
1.334 + flush = (s->last_lit == s->lit_bufsize-1); \
1.335 + }
1.336 +#else
1.337 +# define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
1.338 +# define _tr_tally_dist(s, distance, length, flush) \
1.339 + flush = _tr_tally(s, distance, length)
1.340 +#endif
1.341 +
1.342 +#endif /* DEFLATE_H */