#ifndef DEFLATE_H_ #define DEFLATE_H_ /* deflate.h -- internal compression state * Copyright (C) 1995-2012 Jean-loup Gailly * For conditions of distribution and use, see copyright notice in zlib.h */ /* WARNING: this file should *not* be used by applications. It is part of the implementation of the compression library and is subject to change. Applications should only use zlib.h. */ /* @(#) $Id$ */ #include "zutil.h" /* define NO_GZIP when compiling if you want to disable gzip header and trailer creation by deflate(). NO_GZIP would be used to avoid linking in the crc code when it is not needed. For shared libraries, gzip encoding should be left enabled. */ #ifndef NO_GZIP # define GZIP #endif #define NIL 0 /* Tail of hash chains */ /* =========================================================================== * Internal compression state. */ #define LENGTH_CODES 29 /* number of length codes, not counting the special END_BLOCK code */ #define LITERALS 256 /* number of literal bytes 0..255 */ #define L_CODES (LITERALS+1+LENGTH_CODES) /* number of Literal or Length codes, including the END_BLOCK code */ #define D_CODES 30 /* number of distance codes */ #define BL_CODES 19 /* number of codes used to transfer the bit lengths */ #define HEAP_SIZE (2*L_CODES+1) /* maximum heap size */ #define MAX_BITS 15 /* All codes must not exceed MAX_BITS bits */ #define Buf_size 16 /* size of bit buffer in bi_buf */ #define END_BLOCK 256 /* end of block literal code */ #define INIT_STATE 42 #define EXTRA_STATE 69 #define NAME_STATE 73 #define COMMENT_STATE 91 #define HCRC_STATE 103 #define BUSY_STATE 113 #define FINISH_STATE 666 /* Stream status */ /* Data structure describing a single value and its code string. */ typedef struct ct_data_s { union { uint16_t freq; /* frequency count */ uint16_t code; /* bit string */ } fc; union { uint16_t dad; /* father node in Huffman tree */ uint16_t len; /* length of bit string */ } dl; } ct_data; #define Freq fc.freq #define Code fc.code #define Dad dl.dad #define Len dl.len typedef struct static_tree_desc_s static_tree_desc; typedef struct tree_desc_s { ct_data *dyn_tree; /* the dynamic tree */ int max_code; /* largest code with non zero frequency */ const static_tree_desc *stat_desc; /* the corresponding static tree */ } tree_desc; typedef uint16_t Pos; typedef unsigned IPos; /* A Pos is an index in the character window. We use short instead of int to * save space in the various tables. IPos is used only for parameter passing. */ typedef struct internal_state { z_stream *strm; /* pointer back to this zlib stream */ int status; /* as the name implies */ unsigned char *pending_buf; /* output still pending */ unsigned long pending_buf_size; /* size of pending_buf */ unsigned char *pending_out; /* next pending byte to output to the stream */ unsigned int pending; /* nb of bytes in the pending buffer */ int wrap; /* bit 0 true for zlib, bit 1 true for gzip */ gz_headerp gzhead; /* gzip header information to write */ unsigned int gzindex; /* where in extra, name, or comment */ unsigned char method; /* can only be DEFLATED */ int last_flush; /* value of flush param for previous deflate call */ #ifdef X86_PCLMULQDQ_CRC unsigned ALIGNED_(16) crc0[4 * 5]; #endif /* used by deflate.c: */ unsigned int w_size; /* LZ77 window size (32K by default) */ unsigned int w_bits; /* log2(w_size) (8..16) */ unsigned int w_mask; /* w_size - 1 */ unsigned char *window; /* Sliding window. Input bytes are read into the second half of the window, * and move to the first half later to keep a dictionary of at least wSize * bytes. With this organization, matches are limited to a distance of * wSize-MAX_MATCH bytes, but this ensures that IO is always * performed with a length multiple of the block size. Also, it limits * the window size to 64K, which is quite useful on MSDOS. * To do: use the user input buffer as sliding window. */ unsigned long window_size; /* Actual size of window: 2*wSize, except when the user input buffer * is directly used as sliding window. */ Pos *prev; /* Link to older string with same hash index. To limit the size of this * array to 64K, this link is maintained only for the last 32K strings. * An index in this array is thus a window index modulo 32K. */ Pos *head; /* Heads of the hash chains or NIL. */ unsigned int ins_h; /* hash index of string to be inserted */ unsigned int hash_size; /* number of elements in hash table */ unsigned int hash_bits; /* log2(hash_size) */ unsigned int hash_mask; /* hash_size-1 */ unsigned int hash_shift; /* Number of bits by which ins_h must be shifted at each input * step. It must be such that after MIN_MATCH steps, the oldest * byte no longer takes part in the hash key, that is: * hash_shift * MIN_MATCH >= hash_bits */ long block_start; /* Window position at the beginning of the current output block. Gets * negative when the window is moved backwards. */ unsigned int match_length; /* length of best match */ IPos prev_match; /* previous match */ int match_available; /* set if previous match exists */ unsigned int strstart; /* start of string to insert */ unsigned int match_start; /* start of matching string */ unsigned int lookahead; /* number of valid bytes ahead in window */ unsigned int prev_length; /* Length of the best match at previous step. Matches not greater than this * are discarded. This is used in the lazy match evaluation. */ unsigned int max_chain_length; /* To speed up deflation, hash chains are never searched beyond this * length. A higher limit improves compression ratio but degrades the * speed. */ unsigned int max_lazy_match; /* Attempt to find a better match only when the current match is strictly * smaller than this value. This mechanism is used only for compression * levels >= 4. */ # define max_insert_length max_lazy_match /* Insert new strings in the hash table only if the match length is not * greater than this length. This saves time but degrades compression. * max_insert_length is used only for compression levels <= 3. */ int level; /* compression level (1..9) */ int strategy; /* favor or force Huffman coding*/ unsigned int good_match; /* Use a faster search when the previous match is longer than this */ int nice_match; /* Stop searching when current match exceeds this */ /* used by trees.c: */ /* Didn't use ct_data typedef below to suppress compiler warning */ struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ struct tree_desc_s l_desc; /* desc. for literal tree */ struct tree_desc_s d_desc; /* desc. for distance tree */ struct tree_desc_s bl_desc; /* desc. for bit length tree */ uint16_t bl_count[MAX_BITS+1]; /* number of codes at each bit length for an optimal tree */ int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ int heap_len; /* number of elements in the heap */ int heap_max; /* element of largest frequency */ /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. * The same heap array is used to build all trees. */ unsigned char depth[2*L_CODES+1]; /* Depth of each subtree used as tie breaker for trees of equal frequency */ unsigned char *l_buf; /* buffer for literals or lengths */ unsigned int lit_bufsize; /* Size of match buffer for literals/lengths. There are 4 reasons for * limiting lit_bufsize to 64K: * - frequencies can be kept in 16 bit counters * - if compression is not successful for the first block, all input * data is still in the window so we can still emit a stored block even * when input comes from standard input. (This can also be done for * all blocks if lit_bufsize is not greater than 32K.) * - if compression is not successful for a file smaller than 64K, we can * even emit a stored file instead of a stored block (saving 5 bytes). * This is applicable only for zip (not gzip or zlib). * - creating new Huffman trees less frequently may not provide fast * adaptation to changes in the input data statistics. (Take for * example a binary file with poorly compressible code followed by * a highly compressible string table.) Smaller buffer sizes give * fast adaptation but have of course the overhead of transmitting * trees more frequently. * - I can't count above 4 */ unsigned int last_lit; /* running index in l_buf */ uint16_t *d_buf; /* Buffer for distances. To simplify the code, d_buf and l_buf have * the same number of elements. To use different lengths, an extra flag * array would be necessary. */ unsigned long opt_len; /* bit length of current block with optimal trees */ unsigned long static_len; /* bit length of current block with static trees */ unsigned int matches; /* number of string matches in current block */ unsigned int insert; /* bytes at end of window left to insert */ #ifdef DEBUG unsigned long compressed_len; /* total bit length of compressed file mod 2^32 */ unsigned long bits_sent; /* bit length of compressed data sent mod 2^32 */ #endif uint16_t bi_buf; /* Output buffer. bits are inserted starting at the bottom (least * significant bits). */ int bi_valid; /* Number of valid bits in bi_buf. All bits above the last valid bit * are always zero. */ unsigned long high_water; /* High water mark offset in window for initialized bytes -- bytes above * this are set to zero in order to avoid memory check warnings when * longest match routines access bytes past the input. This is then * updated to the new high water mark. */ } deflate_state; typedef enum { need_more, /* block not completed, need more input or more output */ block_done, /* block flush performed */ finish_started, /* finish started, need only more output at next deflate */ finish_done /* finish done, accept no more input or output */ } block_state; /* Output a byte on the stream. * IN assertion: there is enough room in pending_buf. */ #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} /* =========================================================================== * Output a short LSB first on the stream. * IN assertion: there is enough room in pendingBuf. */ #if defined(__x86_64) || defined(__i386_) /* Compared to the else-clause's implementation, there are few advantages: * - s->pending is loaded only once (else-clause's implementation needs to * load s->pending twice due to the alias between s->pending and * s->pending_buf[]. * - no instructions for extracting bytes from short. * - needs less registers * - stores to adjacent bytes are merged into a single store, albeit at the * cost of penalty of potentially unaligned access. */ #define put_short(s, w) { \ s->pending += 2; \ *(uint16_t*)(&s->pending_buf[s->pending - 2]) = (w) ; \ } #else #define put_short(s, w) { \ put_byte(s, (unsigned char)((w) & 0xff)); \ put_byte(s, (unsigned char)((uint16_t)(w) >> 8)); \ } #endif #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) /* Minimum amount of lookahead, except at the end of the input file. * See deflate.c for comments about the MIN_MATCH+1. */ #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) /* In order to simplify the code, particularly on 16 bit machines, match * distances are limited to MAX_DIST instead of WSIZE. */ #define WIN_INIT MAX_MATCH /* Number of bytes after end of data in window to initialize in order to avoid memory checker errors from longest match routines */ /* in trees.c */ void ZLIB_INTERNAL _tr_init(deflate_state *s); int ZLIB_INTERNAL _tr_tally(deflate_state *s, unsigned dist, unsigned lc); void ZLIB_INTERNAL _tr_flush_block(deflate_state *s, char *buf, unsigned long stored_len, int last); void ZLIB_INTERNAL _tr_flush_bits(deflate_state *s); void ZLIB_INTERNAL _tr_align(deflate_state *s); void ZLIB_INTERNAL _tr_stored_block(deflate_state *s, char *buf, unsigned long stored_len, int last); void ZLIB_INTERNAL bi_windup(deflate_state *s); #define d_code(dist) ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)]) /* Mapping from a distance to a distance code. dist is the distance - 1 and * must not have side effects. _dist_code[256] and _dist_code[257] are never * used. */ #ifndef DEBUG /* Inline versions of _tr_tally for speed: */ # if defined(GEN_TREES_H) extern unsigned char ZLIB_INTERNAL _length_code[]; extern unsigned char ZLIB_INTERNAL _dist_code[]; # else extern const unsigned char ZLIB_INTERNAL _length_code[]; extern const unsigned char ZLIB_INTERNAL _dist_code[]; # endif # define _tr_tally_lit(s, c, flush) \ { unsigned char cc = (c); \ s->d_buf[s->last_lit] = 0; \ s->l_buf[s->last_lit++] = cc; \ s->dyn_ltree[cc].Freq++; \ flush = (s->last_lit == s->lit_bufsize-1); \ } # define _tr_tally_dist(s, distance, length, flush) \ { unsigned char len = (length); \ uint16_t dist = (distance); \ s->d_buf[s->last_lit] = dist; \ s->l_buf[s->last_lit++] = len; \ dist--; \ s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \ s->dyn_dtree[d_code(dist)].Freq++; \ flush = (s->last_lit == s->lit_bufsize-1); \ } #else # define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c) # define _tr_tally_dist(s, distance, length, flush) \ flush = _tr_tally(s, distance, length) #endif /* =========================================================================== * Update a hash value with the given input byte * IN assertion: all calls to to UPDATE_HASH are made with consecutive * input characters, so that a running hash key can be computed from the * previous key instead of complete recalculation each time. */ #ifdef X86_SSE4_2_CRC_HASH #define UPDATE_HASH(s, h, i) \ do {\ if (s->level < 6) \ h = (3483 * (s->window[i]) +\ 23081* (s->window[i+1]) +\ 6954 * (s->window[i+2]) +\ 20947* (s->window[i+3])) & s->hash_mask;\ else\ h = (25881* (s->window[i]) +\ 24674* (s->window[i+1]) +\ 25811* (s->window[i+2])) & s->hash_mask;\ } while (0) #else # define UPDATE_HASH(s, h, i) (h = (((h) << s->hash_shift) ^ (s->window[i + (MIN_MATCH-1)])) & s->hash_mask) #endif #ifndef DEBUG # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) /* Send a code of the given tree. c and tree must not have side effects */ #else /* DEBUG */ # define send_code(s, c, tree) \ { if (z_verbose > 2) { \ fprintf(stderr, "\ncd %3d ", (c)); \ } \ send_bits(s, tree[c].Code, tree[c].Len); \ } #endif #ifdef DEBUG /* =========================================================================== * Send a value on a given number of bits. * IN assertion: length <= 16 and value fits in length bits. */ local void send_bits(deflate_state *s, int value, int length) { Tracevv((stderr, " l %2d v %4x ", length, value)); Assert(length > 0 && length <= 15, "invalid length"); s->bits_sent += (unsigned long)length; /* If not enough room in bi_buf, use (valid) bits from bi_buf and * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) * unused bits in value. */ if (s->bi_valid > (int)Buf_size - length) { s->bi_buf |= (uint16_t)value << s->bi_valid; put_short(s, s->bi_buf); s->bi_buf = (uint16_t)value >> (Buf_size - s->bi_valid); s->bi_valid += length - Buf_size; } else { s->bi_buf |= (uint16_t)value << s->bi_valid; s->bi_valid += length; } } #else #define send_bits(s, value, length) \ { int len = length;\ if (s->bi_valid > (int)Buf_size - len) {\ int val = value;\ s->bi_buf |= (uint16_t)val << s->bi_valid;\ put_short(s, s->bi_buf);\ s->bi_buf = (uint16_t)val >> (Buf_size - s->bi_valid);\ s->bi_valid += len - Buf_size;\ } else {\ s->bi_buf |= (uint16_t)(value) << s->bi_valid;\ s->bi_valid += len;\ }\ } #endif #endif /* DEFLATE_H_ */