5128eecc9f 2011-02-23 kinaba: /* trees.c -- output deflated data using Huffman coding 5128eecc9f 2011-02-23 kinaba: * Copyright (C) 1995-1998 Jean-loup Gailly 5128eecc9f 2011-02-23 kinaba: * For conditions of distribution and use, see copyright notice in zlib.h 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* 5128eecc9f 2011-02-23 kinaba: * ALGORITHM 5128eecc9f 2011-02-23 kinaba: * 5128eecc9f 2011-02-23 kinaba: * The "deflation" process uses several Huffman trees. The more 5128eecc9f 2011-02-23 kinaba: * common source values are represented by shorter bit sequences. 5128eecc9f 2011-02-23 kinaba: * 5128eecc9f 2011-02-23 kinaba: * Each code tree is stored in a compressed form which is itself 5128eecc9f 2011-02-23 kinaba: * a Huffman encoding of the lengths of all the code strings (in 5128eecc9f 2011-02-23 kinaba: * ascending order by source values). The actual code strings are 5128eecc9f 2011-02-23 kinaba: * reconstructed from the lengths in the inflate process, as described 5128eecc9f 2011-02-23 kinaba: * in the deflate specification. 5128eecc9f 2011-02-23 kinaba: * 5128eecc9f 2011-02-23 kinaba: * REFERENCES 5128eecc9f 2011-02-23 kinaba: * 5128eecc9f 2011-02-23 kinaba: * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 5128eecc9f 2011-02-23 kinaba: * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 5128eecc9f 2011-02-23 kinaba: * 5128eecc9f 2011-02-23 kinaba: * Storer, James A. 5128eecc9f 2011-02-23 kinaba: * Data Compression: Methods and Theory, pp. 49-50. 5128eecc9f 2011-02-23 kinaba: * Computer Science Press, 1988. ISBN 0-7167-8156-5. 5128eecc9f 2011-02-23 kinaba: * 5128eecc9f 2011-02-23 kinaba: * Sedgewick, R. 5128eecc9f 2011-02-23 kinaba: * Algorithms, p290. 5128eecc9f 2011-02-23 kinaba: * Addison-Wesley, 1983. ISBN 0-201-06672-6. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* @(#) $Id$ */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* #define GEN_TREES_H */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #include "deflate.h" 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: # include <ctype.h> 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Constants 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define MAX_BL_BITS 7 5128eecc9f 2011-02-23 kinaba: /* Bit length codes must not exceed MAX_BL_BITS bits */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define END_BLOCK 256 5128eecc9f 2011-02-23 kinaba: /* end of block literal code */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define REP_3_6 16 5128eecc9f 2011-02-23 kinaba: /* repeat previous bit length 3-6 times (2 bits of repeat count) */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define REPZ_3_10 17 5128eecc9f 2011-02-23 kinaba: /* repeat a zero length 3-10 times (3 bits of repeat count) */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define REPZ_11_138 18 5128eecc9f 2011-02-23 kinaba: /* repeat a zero length 11-138 times (7 bits of repeat count) */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 5128eecc9f 2011-02-23 kinaba: = {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}; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local const int extra_dbits[D_CODES] /* extra bits for each distance code */ 5128eecc9f 2011-02-23 kinaba: = {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}; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 5128eecc9f 2011-02-23 kinaba: = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local const uch bl_order[BL_CODES] 5128eecc9f 2011-02-23 kinaba: = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 5128eecc9f 2011-02-23 kinaba: /* The lengths of the bit length codes are sent in order of decreasing 5128eecc9f 2011-02-23 kinaba: * probability, to avoid transmitting the lengths for unused bit length codes. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define Buf_size (8 * 2*sizeof(char)) 5128eecc9f 2011-02-23 kinaba: /* Number of bits used within bi_buf. (bi_buf might be implemented on 5128eecc9f 2011-02-23 kinaba: * more than 16 bits on some systems.) 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Local data. These are initialized only once. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define DIST_CODE_LEN 512 /* see definition of array dist_code below */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #if defined(GEN_TREES_H) || !defined(STDC) 5128eecc9f 2011-02-23 kinaba: /* non ANSI compilers may not accept trees.h */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local ct_data static_ltree[L_CODES+2]; 5128eecc9f 2011-02-23 kinaba: /* The static literal tree. Since the bit lengths are imposed, there is no 5128eecc9f 2011-02-23 kinaba: * need for the L_CODES extra codes used during heap construction. However 5128eecc9f 2011-02-23 kinaba: * The codes 286 and 287 are needed to build a canonical tree (see _tr_init 5128eecc9f 2011-02-23 kinaba: * below). 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local ct_data static_dtree[D_CODES]; 5128eecc9f 2011-02-23 kinaba: /* The static distance tree. (Actually a trivial tree since all codes use 5128eecc9f 2011-02-23 kinaba: * 5 bits.) 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: uch _dist_code[DIST_CODE_LEN]; 5128eecc9f 2011-02-23 kinaba: /* Distance codes. The first 256 values correspond to the distances 5128eecc9f 2011-02-23 kinaba: * 3 .. 258, the last 256 values correspond to the top 8 bits of 5128eecc9f 2011-02-23 kinaba: * the 15 bit distances. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: uch _length_code[MAX_MATCH-MIN_MATCH+1]; 5128eecc9f 2011-02-23 kinaba: /* length code for each normalized match length (0 == MIN_MATCH) */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local int base_length[LENGTH_CODES]; 5128eecc9f 2011-02-23 kinaba: /* First normalized length for each code (0 = MIN_MATCH) */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local int base_dist[D_CODES]; 5128eecc9f 2011-02-23 kinaba: /* First normalized distance for each code (0 = distance of 1) */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #else 5128eecc9f 2011-02-23 kinaba: # include "trees.h" 5128eecc9f 2011-02-23 kinaba: #endif /* GEN_TREES_H */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: struct static_tree_desc_s { 5128eecc9f 2011-02-23 kinaba: const ct_data *static_tree; /* static tree or NULL */ 5128eecc9f 2011-02-23 kinaba: const intf *extra_bits; /* extra bits for each code or NULL */ 5128eecc9f 2011-02-23 kinaba: int extra_base; /* base index for extra_bits */ 5128eecc9f 2011-02-23 kinaba: int elems; /* max number of elements in the tree */ 5128eecc9f 2011-02-23 kinaba: int max_length; /* max bit length for the codes */ 5128eecc9f 2011-02-23 kinaba: }; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local static_tree_desc static_l_desc = 5128eecc9f 2011-02-23 kinaba: {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local static_tree_desc static_d_desc = 5128eecc9f 2011-02-23 kinaba: {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local static_tree_desc static_bl_desc = 5128eecc9f 2011-02-23 kinaba: {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Local (static) routines in this file. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local void tr_static_init OF((void)); 5128eecc9f 2011-02-23 kinaba: local void init_block OF((deflate_state *s)); 5128eecc9f 2011-02-23 kinaba: local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 5128eecc9f 2011-02-23 kinaba: local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 5128eecc9f 2011-02-23 kinaba: local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 5128eecc9f 2011-02-23 kinaba: local void build_tree OF((deflate_state *s, tree_desc *desc)); 5128eecc9f 2011-02-23 kinaba: local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 5128eecc9f 2011-02-23 kinaba: local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 5128eecc9f 2011-02-23 kinaba: local int build_bl_tree OF((deflate_state *s)); 5128eecc9f 2011-02-23 kinaba: local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 5128eecc9f 2011-02-23 kinaba: int blcodes)); 5128eecc9f 2011-02-23 kinaba: local void compress_block OF((deflate_state *s, ct_data *ltree, 5128eecc9f 2011-02-23 kinaba: ct_data *dtree)); 5128eecc9f 2011-02-23 kinaba: local void set_data_type OF((deflate_state *s)); 5128eecc9f 2011-02-23 kinaba: local unsigned bi_reverse OF((unsigned value, int length)); 5128eecc9f 2011-02-23 kinaba: local void bi_windup OF((deflate_state *s)); 5128eecc9f 2011-02-23 kinaba: local void bi_flush OF((deflate_state *s)); 5128eecc9f 2011-02-23 kinaba: local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 5128eecc9f 2011-02-23 kinaba: int header)); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #ifdef GEN_TREES_H 5128eecc9f 2011-02-23 kinaba: local void gen_trees_header OF((void)); 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #ifndef DEBUG 5128eecc9f 2011-02-23 kinaba: # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) 5128eecc9f 2011-02-23 kinaba: /* Send a code of the given tree. c and tree must not have side effects */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #else /* DEBUG */ 5128eecc9f 2011-02-23 kinaba: # define send_code(s, c, tree) \ 5128eecc9f 2011-02-23 kinaba: { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ 5128eecc9f 2011-02-23 kinaba: send_bits(s, tree[c].Code, tree[c].Len); } 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Output a short LSB first on the stream. 5128eecc9f 2011-02-23 kinaba: * IN assertion: there is enough room in pendingBuf. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: #define put_short(s, w) { \ 5128eecc9f 2011-02-23 kinaba: put_byte(s, (uch)((w) & 0xff)); \ 5128eecc9f 2011-02-23 kinaba: put_byte(s, (uch)((ush)(w) >> 8)); \ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Send a value on a given number of bits. 5128eecc9f 2011-02-23 kinaba: * IN assertion: length <= 16 and value fits in length bits. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: local void send_bits OF((deflate_state *s, int value, int length)); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: local void send_bits(s, value, length) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: int value; /* value to send */ 5128eecc9f 2011-02-23 kinaba: int length; /* number of bits */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: Tracevv((stderr," l %2d v %4x ", length, value)); 5128eecc9f 2011-02-23 kinaba: Assert(length > 0 && length <= 15, "invalid length"); 5128eecc9f 2011-02-23 kinaba: s->bits_sent += (ulg)length; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* If not enough room in bi_buf, use (valid) bits from bi_buf and 5128eecc9f 2011-02-23 kinaba: * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 5128eecc9f 2011-02-23 kinaba: * unused bits in value. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: if (s->bi_valid > (int)Buf_size - length) { 5128eecc9f 2011-02-23 kinaba: s->bi_buf |= (value << s->bi_valid); 5128eecc9f 2011-02-23 kinaba: put_short(s, s->bi_buf); 5128eecc9f 2011-02-23 kinaba: s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 5128eecc9f 2011-02-23 kinaba: s->bi_valid += length - Buf_size; 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: s->bi_buf |= value << s->bi_valid; 5128eecc9f 2011-02-23 kinaba: s->bi_valid += length; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: #else /* !DEBUG */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define send_bits(s, value, length) \ 5128eecc9f 2011-02-23 kinaba: { int len = length;\ 5128eecc9f 2011-02-23 kinaba: if (s->bi_valid > (int)Buf_size - len) {\ 5128eecc9f 2011-02-23 kinaba: int val = value;\ 5128eecc9f 2011-02-23 kinaba: s->bi_buf |= (val << s->bi_valid);\ 5128eecc9f 2011-02-23 kinaba: put_short(s, s->bi_buf);\ 5128eecc9f 2011-02-23 kinaba: s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ 5128eecc9f 2011-02-23 kinaba: s->bi_valid += len - Buf_size;\ 5128eecc9f 2011-02-23 kinaba: } else {\ 5128eecc9f 2011-02-23 kinaba: s->bi_buf |= (value) << s->bi_valid;\ 5128eecc9f 2011-02-23 kinaba: s->bi_valid += len;\ 5128eecc9f 2011-02-23 kinaba: }\ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: #endif /* DEBUG */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define MAX(a,b) (a >= b ? a : b) 5128eecc9f 2011-02-23 kinaba: /* the arguments must not have side effects */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Initialize the various 'constant' tables. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void tr_static_init() 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: #if defined(GEN_TREES_H) || !defined(STDC) 5128eecc9f 2011-02-23 kinaba: static int static_init_done = 0; 5128eecc9f 2011-02-23 kinaba: int n; /* iterates over tree elements */ 5128eecc9f 2011-02-23 kinaba: int bits; /* bit counter */ 5128eecc9f 2011-02-23 kinaba: int length; /* length value */ 5128eecc9f 2011-02-23 kinaba: int code; /* code value */ 5128eecc9f 2011-02-23 kinaba: int dist; /* distance index */ 5128eecc9f 2011-02-23 kinaba: ush bl_count[MAX_BITS+1]; 5128eecc9f 2011-02-23 kinaba: /* number of codes at each bit length for an optimal tree */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: if (static_init_done) return; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* For some embedded targets, global variables are not initialized: */ 5128eecc9f 2011-02-23 kinaba: static_l_desc.static_tree = static_ltree; 5128eecc9f 2011-02-23 kinaba: static_l_desc.extra_bits = extra_lbits; 5128eecc9f 2011-02-23 kinaba: static_d_desc.static_tree = static_dtree; 5128eecc9f 2011-02-23 kinaba: static_d_desc.extra_bits = extra_dbits; 5128eecc9f 2011-02-23 kinaba: static_bl_desc.extra_bits = extra_blbits; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Initialize the mapping length (0..255) -> length code (0..28) */ 5128eecc9f 2011-02-23 kinaba: length = 0; 5128eecc9f 2011-02-23 kinaba: for (code = 0; code < LENGTH_CODES-1; code++) { 5128eecc9f 2011-02-23 kinaba: base_length[code] = length; 5128eecc9f 2011-02-23 kinaba: for (n = 0; n < (1<<extra_lbits[code]); n++) { 5128eecc9f 2011-02-23 kinaba: _length_code[length++] = (uch)code; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: Assert (length == 256, "tr_static_init: length != 256"); 5128eecc9f 2011-02-23 kinaba: /* Note that the length 255 (match length 258) can be represented 5128eecc9f 2011-02-23 kinaba: * in two different ways: code 284 + 5 bits or code 285, so we 5128eecc9f 2011-02-23 kinaba: * overwrite length_code[255] to use the best encoding: 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: _length_code[length-1] = (uch)code; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 5128eecc9f 2011-02-23 kinaba: dist = 0; 5128eecc9f 2011-02-23 kinaba: for (code = 0 ; code < 16; code++) { 5128eecc9f 2011-02-23 kinaba: base_dist[code] = dist; 5128eecc9f 2011-02-23 kinaba: for (n = 0; n < (1<<extra_dbits[code]); n++) { 5128eecc9f 2011-02-23 kinaba: _dist_code[dist++] = (uch)code; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: Assert (dist == 256, "tr_static_init: dist != 256"); 5128eecc9f 2011-02-23 kinaba: dist >>= 7; /* from now on, all distances are divided by 128 */ 5128eecc9f 2011-02-23 kinaba: for ( ; code < D_CODES; code++) { 5128eecc9f 2011-02-23 kinaba: base_dist[code] = dist << 7; 5128eecc9f 2011-02-23 kinaba: for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 5128eecc9f 2011-02-23 kinaba: _dist_code[256 + dist++] = (uch)code; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: Assert (dist == 256, "tr_static_init: 256+dist != 512"); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Construct the codes of the static literal tree */ 5128eecc9f 2011-02-23 kinaba: for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 5128eecc9f 2011-02-23 kinaba: n = 0; 5128eecc9f 2011-02-23 kinaba: while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 5128eecc9f 2011-02-23 kinaba: while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 5128eecc9f 2011-02-23 kinaba: while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 5128eecc9f 2011-02-23 kinaba: while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 5128eecc9f 2011-02-23 kinaba: /* Codes 286 and 287 do not exist, but we must include them in the 5128eecc9f 2011-02-23 kinaba: * tree construction to get a canonical Huffman tree (longest code 5128eecc9f 2011-02-23 kinaba: * all ones) 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* The static distance tree is trivial: */ 5128eecc9f 2011-02-23 kinaba: for (n = 0; n < D_CODES; n++) { 5128eecc9f 2011-02-23 kinaba: static_dtree[n].Len = 5; 5128eecc9f 2011-02-23 kinaba: static_dtree[n].Code = bi_reverse((unsigned)n, 5); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: static_init_done = 1; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: # ifdef GEN_TREES_H 5128eecc9f 2011-02-23 kinaba: gen_trees_header(); 5128eecc9f 2011-02-23 kinaba: # endif 5128eecc9f 2011-02-23 kinaba: #endif /* defined(GEN_TREES_H) || !defined(STDC) */ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Genererate the file trees.h describing the static trees. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: #ifdef GEN_TREES_H 5128eecc9f 2011-02-23 kinaba: # ifndef DEBUG 5128eecc9f 2011-02-23 kinaba: # include <stdio.h> 5128eecc9f 2011-02-23 kinaba: # endif 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: # define SEPARATOR(i, last, width) \ 5128eecc9f 2011-02-23 kinaba: ((i) == (last)? "\n};\n\n" : \ 5128eecc9f 2011-02-23 kinaba: ((i) % (width) == (width)-1 ? ",\n" : ", ")) 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: void gen_trees_header() 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: FILE *header = fopen("trees.h", "w"); 5128eecc9f 2011-02-23 kinaba: int i; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: Assert (header != NULL, "Can't open trees.h"); 5128eecc9f 2011-02-23 kinaba: fprintf(header, 5128eecc9f 2011-02-23 kinaba: "/* header created automatically with -DGEN_TREES_H */\n\n"); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n"); 5128eecc9f 2011-02-23 kinaba: for (i = 0; i < L_CODES+2; i++) { 5128eecc9f 2011-02-23 kinaba: fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code, 5128eecc9f 2011-02-23 kinaba: static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n"); 5128eecc9f 2011-02-23 kinaba: for (i = 0; i < D_CODES; i++) { 5128eecc9f 2011-02-23 kinaba: fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code, 5128eecc9f 2011-02-23 kinaba: static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n"); 5128eecc9f 2011-02-23 kinaba: for (i = 0; i < DIST_CODE_LEN; i++) { 5128eecc9f 2011-02-23 kinaba: fprintf(header, "%2u%s", _dist_code[i], 5128eecc9f 2011-02-23 kinaba: SEPARATOR(i, DIST_CODE_LEN-1, 20)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n"); 5128eecc9f 2011-02-23 kinaba: for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) { 5128eecc9f 2011-02-23 kinaba: fprintf(header, "%2u%s", _length_code[i], 5128eecc9f 2011-02-23 kinaba: SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: fprintf(header, "local const int base_length[LENGTH_CODES] = {\n"); 5128eecc9f 2011-02-23 kinaba: for (i = 0; i < LENGTH_CODES; i++) { 5128eecc9f 2011-02-23 kinaba: fprintf(header, "%1u%s", base_length[i], 5128eecc9f 2011-02-23 kinaba: SEPARATOR(i, LENGTH_CODES-1, 20)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: fprintf(header, "local const int base_dist[D_CODES] = {\n"); 5128eecc9f 2011-02-23 kinaba: for (i = 0; i < D_CODES; i++) { 5128eecc9f 2011-02-23 kinaba: fprintf(header, "%5u%s", base_dist[i], 5128eecc9f 2011-02-23 kinaba: SEPARATOR(i, D_CODES-1, 10)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: fclose(header); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: #endif /* GEN_TREES_H */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Initialize the tree data structures for a new zlib stream. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: void _tr_init(s) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: tr_static_init(); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->l_desc.dyn_tree = s->dyn_ltree; 5128eecc9f 2011-02-23 kinaba: s->l_desc.stat_desc = &static_l_desc; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->d_desc.dyn_tree = s->dyn_dtree; 5128eecc9f 2011-02-23 kinaba: s->d_desc.stat_desc = &static_d_desc; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->bl_desc.dyn_tree = s->bl_tree; 5128eecc9f 2011-02-23 kinaba: s->bl_desc.stat_desc = &static_bl_desc; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->bi_buf = 0; 5128eecc9f 2011-02-23 kinaba: s->bi_valid = 0; 5128eecc9f 2011-02-23 kinaba: s->last_eob_len = 8; /* enough lookahead for inflate */ 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->compressed_len = 0L; 5128eecc9f 2011-02-23 kinaba: s->bits_sent = 0L; 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Initialize the first block of the first file: */ 5128eecc9f 2011-02-23 kinaba: init_block(s); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Initialize a new block. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void init_block(s) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: int n; /* iterates over tree elements */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Initialize the trees. */ 5128eecc9f 2011-02-23 kinaba: for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 5128eecc9f 2011-02-23 kinaba: for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 5128eecc9f 2011-02-23 kinaba: for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->dyn_ltree[END_BLOCK].Freq = 1; 5128eecc9f 2011-02-23 kinaba: s->opt_len = s->static_len = 0L; 5128eecc9f 2011-02-23 kinaba: s->last_lit = s->matches = 0; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #define SMALLEST 1 5128eecc9f 2011-02-23 kinaba: /* Index within the heap array of least frequent node in the Huffman tree */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Remove the smallest element from the heap and recreate the heap with 5128eecc9f 2011-02-23 kinaba: * one less element. Updates heap and heap_len. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: #define pqremove(s, tree, top) \ 5128eecc9f 2011-02-23 kinaba: {\ 5128eecc9f 2011-02-23 kinaba: top = s->heap[SMALLEST]; \ 5128eecc9f 2011-02-23 kinaba: s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 5128eecc9f 2011-02-23 kinaba: pqdownheap(s, tree, SMALLEST); \ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Compares to subtrees, using the tree depth as tie breaker when 5128eecc9f 2011-02-23 kinaba: * the subtrees have equal frequency. This minimizes the worst case length. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: #define smaller(tree, n, m, depth) \ 5128eecc9f 2011-02-23 kinaba: (tree[n].Freq < tree[m].Freq || \ 5128eecc9f 2011-02-23 kinaba: (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Restore the heap property by moving down the tree starting at node k, 5128eecc9f 2011-02-23 kinaba: * exchanging a node with the smallest of its two sons if necessary, stopping 5128eecc9f 2011-02-23 kinaba: * when the heap property is re-established (each father smaller than its 5128eecc9f 2011-02-23 kinaba: * two sons). 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void pqdownheap(s, tree, k) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: ct_data *tree; /* the tree to restore */ 5128eecc9f 2011-02-23 kinaba: int k; /* node to move down */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: int v = s->heap[k]; 5128eecc9f 2011-02-23 kinaba: int j = k << 1; /* left son of k */ 5128eecc9f 2011-02-23 kinaba: while (j <= s->heap_len) { 5128eecc9f 2011-02-23 kinaba: /* Set j to the smallest of the two sons: */ 5128eecc9f 2011-02-23 kinaba: if (j < s->heap_len && 5128eecc9f 2011-02-23 kinaba: smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 5128eecc9f 2011-02-23 kinaba: j++; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: /* Exit if v is smaller than both sons */ 5128eecc9f 2011-02-23 kinaba: if (smaller(tree, v, s->heap[j], s->depth)) break; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Exchange v with the smallest son */ 5128eecc9f 2011-02-23 kinaba: s->heap[k] = s->heap[j]; k = j; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* And continue down the tree, setting j to the left son of k */ 5128eecc9f 2011-02-23 kinaba: j <<= 1; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: s->heap[k] = v; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Compute the optimal bit lengths for a tree and update the total bit length 5128eecc9f 2011-02-23 kinaba: * for the current block. 5128eecc9f 2011-02-23 kinaba: * IN assertion: the fields freq and dad are set, heap[heap_max] and 5128eecc9f 2011-02-23 kinaba: * above are the tree nodes sorted by increasing frequency. 5128eecc9f 2011-02-23 kinaba: * OUT assertions: the field len is set to the optimal bit length, the 5128eecc9f 2011-02-23 kinaba: * array bl_count contains the frequencies for each bit length. 5128eecc9f 2011-02-23 kinaba: * The length opt_len is updated; static_len is also updated if stree is 5128eecc9f 2011-02-23 kinaba: * not null. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void gen_bitlen(s, desc) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: tree_desc *desc; /* the tree descriptor */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: ct_data *tree = desc->dyn_tree; 5128eecc9f 2011-02-23 kinaba: int max_code = desc->max_code; 5128eecc9f 2011-02-23 kinaba: const ct_data *stree = desc->stat_desc->static_tree; 5128eecc9f 2011-02-23 kinaba: const intf *extra = desc->stat_desc->extra_bits; 5128eecc9f 2011-02-23 kinaba: int base = desc->stat_desc->extra_base; 5128eecc9f 2011-02-23 kinaba: int max_length = desc->stat_desc->max_length; 5128eecc9f 2011-02-23 kinaba: int h; /* heap index */ 5128eecc9f 2011-02-23 kinaba: int n, m; /* iterate over the tree elements */ 5128eecc9f 2011-02-23 kinaba: int bits; /* bit length */ 5128eecc9f 2011-02-23 kinaba: int xbits; /* extra bits */ 5128eecc9f 2011-02-23 kinaba: ush f; /* frequency */ 5128eecc9f 2011-02-23 kinaba: int overflow = 0; /* number of elements with bit length too large */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* In a first pass, compute the optimal bit lengths (which may 5128eecc9f 2011-02-23 kinaba: * overflow in the case of the bit length tree). 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 5128eecc9f 2011-02-23 kinaba: n = s->heap[h]; 5128eecc9f 2011-02-23 kinaba: bits = tree[tree[n].Dad].Len + 1; 5128eecc9f 2011-02-23 kinaba: if (bits > max_length) bits = max_length, overflow++; 5128eecc9f 2011-02-23 kinaba: tree[n].Len = (ush)bits; 5128eecc9f 2011-02-23 kinaba: /* We overwrite tree[n].Dad which is no longer needed */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: if (n > max_code) continue; /* not a leaf node */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->bl_count[bits]++; 5128eecc9f 2011-02-23 kinaba: xbits = 0; 5128eecc9f 2011-02-23 kinaba: if (n >= base) xbits = extra[n-base]; 5128eecc9f 2011-02-23 kinaba: f = tree[n].Freq; 5128eecc9f 2011-02-23 kinaba: s->opt_len += (ulg)f * (bits + xbits); 5128eecc9f 2011-02-23 kinaba: if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: if (overflow == 0) return; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: Trace((stderr,"\nbit length overflow\n")); 5128eecc9f 2011-02-23 kinaba: /* This happens for example on obj2 and pic of the Calgary corpus */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Find the first bit length which could increase: */ 5128eecc9f 2011-02-23 kinaba: do { 5128eecc9f 2011-02-23 kinaba: bits = max_length-1; 5128eecc9f 2011-02-23 kinaba: while (s->bl_count[bits] == 0) bits--; 5128eecc9f 2011-02-23 kinaba: s->bl_count[bits]--; /* move one leaf down the tree */ 5128eecc9f 2011-02-23 kinaba: s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 5128eecc9f 2011-02-23 kinaba: s->bl_count[max_length]--; 5128eecc9f 2011-02-23 kinaba: /* The brother of the overflow item also moves one step up, 5128eecc9f 2011-02-23 kinaba: * but this does not affect bl_count[max_length] 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: overflow -= 2; 5128eecc9f 2011-02-23 kinaba: } while (overflow > 0); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Now recompute all bit lengths, scanning in increasing frequency. 5128eecc9f 2011-02-23 kinaba: * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 5128eecc9f 2011-02-23 kinaba: * lengths instead of fixing only the wrong ones. This idea is taken 5128eecc9f 2011-02-23 kinaba: * from 'ar' written by Haruhiko Okumura.) 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: for (bits = max_length; bits != 0; bits--) { 5128eecc9f 2011-02-23 kinaba: n = s->bl_count[bits]; 5128eecc9f 2011-02-23 kinaba: while (n != 0) { 5128eecc9f 2011-02-23 kinaba: m = s->heap[--h]; 5128eecc9f 2011-02-23 kinaba: if (m > max_code) continue; 5128eecc9f 2011-02-23 kinaba: if (tree[m].Len != (unsigned) bits) { 5128eecc9f 2011-02-23 kinaba: Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 5128eecc9f 2011-02-23 kinaba: s->opt_len += ((long)bits - (long)tree[m].Len) 5128eecc9f 2011-02-23 kinaba: *(long)tree[m].Freq; 5128eecc9f 2011-02-23 kinaba: tree[m].Len = (ush)bits; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: n--; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Generate the codes for a given tree and bit counts (which need not be 5128eecc9f 2011-02-23 kinaba: * optimal). 5128eecc9f 2011-02-23 kinaba: * IN assertion: the array bl_count contains the bit length statistics for 5128eecc9f 2011-02-23 kinaba: * the given tree and the field len is set for all tree elements. 5128eecc9f 2011-02-23 kinaba: * OUT assertion: the field code is set for all tree elements of non 5128eecc9f 2011-02-23 kinaba: * zero code length. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void gen_codes (tree, max_code, bl_count) 5128eecc9f 2011-02-23 kinaba: ct_data *tree; /* the tree to decorate */ 5128eecc9f 2011-02-23 kinaba: int max_code; /* largest code with non zero frequency */ 5128eecc9f 2011-02-23 kinaba: ushf *bl_count; /* number of codes at each bit length */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 5128eecc9f 2011-02-23 kinaba: ush code = 0; /* running code value */ 5128eecc9f 2011-02-23 kinaba: int bits; /* bit index */ 5128eecc9f 2011-02-23 kinaba: int n; /* code index */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* The distribution counts are first used to generate the code values 5128eecc9f 2011-02-23 kinaba: * without bit reversal. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: for (bits = 1; bits <= MAX_BITS; bits++) { 5128eecc9f 2011-02-23 kinaba: next_code[bits] = code = (code + bl_count[bits-1]) << 1; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: /* Check that the bit counts in bl_count are consistent. The last code 5128eecc9f 2011-02-23 kinaba: * must be all ones. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 5128eecc9f 2011-02-23 kinaba: "inconsistent bit counts"); 5128eecc9f 2011-02-23 kinaba: Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: for (n = 0; n <= max_code; n++) { 5128eecc9f 2011-02-23 kinaba: int len = tree[n].Len; 5128eecc9f 2011-02-23 kinaba: if (len == 0) continue; 5128eecc9f 2011-02-23 kinaba: /* Now reverse the bits */ 5128eecc9f 2011-02-23 kinaba: tree[n].Code = bi_reverse(next_code[len]++, len); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 5128eecc9f 2011-02-23 kinaba: n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Construct one Huffman tree and assigns the code bit strings and lengths. 5128eecc9f 2011-02-23 kinaba: * Update the total bit length for the current block. 5128eecc9f 2011-02-23 kinaba: * IN assertion: the field freq is set for all tree elements. 5128eecc9f 2011-02-23 kinaba: * OUT assertions: the fields len and code are set to the optimal bit length 5128eecc9f 2011-02-23 kinaba: * and corresponding code. The length opt_len is updated; static_len is 5128eecc9f 2011-02-23 kinaba: * also updated if stree is not null. The field max_code is set. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void build_tree(s, desc) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: tree_desc *desc; /* the tree descriptor */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: ct_data *tree = desc->dyn_tree; 5128eecc9f 2011-02-23 kinaba: const ct_data *stree = desc->stat_desc->static_tree; 5128eecc9f 2011-02-23 kinaba: int elems = desc->stat_desc->elems; 5128eecc9f 2011-02-23 kinaba: int n, m; /* iterate over heap elements */ 5128eecc9f 2011-02-23 kinaba: int max_code = -1; /* largest code with non zero frequency */ 5128eecc9f 2011-02-23 kinaba: int node; /* new node being created */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Construct the initial heap, with least frequent element in 5128eecc9f 2011-02-23 kinaba: * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 5128eecc9f 2011-02-23 kinaba: * heap[0] is not used. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: s->heap_len = 0, s->heap_max = HEAP_SIZE; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: for (n = 0; n < elems; n++) { 5128eecc9f 2011-02-23 kinaba: if (tree[n].Freq != 0) { 5128eecc9f 2011-02-23 kinaba: s->heap[++(s->heap_len)] = max_code = n; 5128eecc9f 2011-02-23 kinaba: s->depth[n] = 0; 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: tree[n].Len = 0; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* The pkzip format requires that at least one distance code exists, 5128eecc9f 2011-02-23 kinaba: * and that at least one bit should be sent even if there is only one 5128eecc9f 2011-02-23 kinaba: * possible code. So to avoid special checks later on we force at least 5128eecc9f 2011-02-23 kinaba: * two codes of non zero frequency. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: while (s->heap_len < 2) { 5128eecc9f 2011-02-23 kinaba: node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 5128eecc9f 2011-02-23 kinaba: tree[node].Freq = 1; 5128eecc9f 2011-02-23 kinaba: s->depth[node] = 0; 5128eecc9f 2011-02-23 kinaba: s->opt_len--; if (stree) s->static_len -= stree[node].Len; 5128eecc9f 2011-02-23 kinaba: /* node is 0 or 1 so it does not have extra bits */ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: desc->max_code = max_code; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 5128eecc9f 2011-02-23 kinaba: * establish sub-heaps of increasing lengths: 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Construct the Huffman tree by repeatedly combining the least two 5128eecc9f 2011-02-23 kinaba: * frequent nodes. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: node = elems; /* next internal node of the tree */ 5128eecc9f 2011-02-23 kinaba: do { 5128eecc9f 2011-02-23 kinaba: pqremove(s, tree, n); /* n = node of least frequency */ 5128eecc9f 2011-02-23 kinaba: m = s->heap[SMALLEST]; /* m = node of next least frequency */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 5128eecc9f 2011-02-23 kinaba: s->heap[--(s->heap_max)] = m; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Create a new node father of n and m */ 5128eecc9f 2011-02-23 kinaba: tree[node].Freq = tree[n].Freq + tree[m].Freq; 5128eecc9f 2011-02-23 kinaba: s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 5128eecc9f 2011-02-23 kinaba: tree[n].Dad = tree[m].Dad = (ush)node; 5128eecc9f 2011-02-23 kinaba: #ifdef DUMP_BL_TREE 5128eecc9f 2011-02-23 kinaba: if (tree == s->bl_tree) { 5128eecc9f 2011-02-23 kinaba: fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 5128eecc9f 2011-02-23 kinaba: node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: /* and insert the new node in the heap */ 5128eecc9f 2011-02-23 kinaba: s->heap[SMALLEST] = node++; 5128eecc9f 2011-02-23 kinaba: pqdownheap(s, tree, SMALLEST); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: } while (s->heap_len >= 2); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* At this point, the fields freq and dad are set. We can now 5128eecc9f 2011-02-23 kinaba: * generate the bit lengths. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: gen_bitlen(s, (tree_desc *)desc); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* The field len is now set, we can generate the bit codes */ 5128eecc9f 2011-02-23 kinaba: gen_codes ((ct_data *)tree, max_code, s->bl_count); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Scan a literal or distance tree to determine the frequencies of the codes 5128eecc9f 2011-02-23 kinaba: * in the bit length tree. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void scan_tree (s, tree, max_code) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: ct_data *tree; /* the tree to be scanned */ 5128eecc9f 2011-02-23 kinaba: int max_code; /* and its largest code of non zero frequency */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: int n; /* iterates over all tree elements */ 5128eecc9f 2011-02-23 kinaba: int prevlen = -1; /* last emitted length */ 5128eecc9f 2011-02-23 kinaba: int curlen; /* length of current code */ 5128eecc9f 2011-02-23 kinaba: int nextlen = tree[0].Len; /* length of next code */ 5128eecc9f 2011-02-23 kinaba: int count = 0; /* repeat count of the current code */ 5128eecc9f 2011-02-23 kinaba: int max_count = 7; /* max repeat count */ 5128eecc9f 2011-02-23 kinaba: int min_count = 4; /* min repeat count */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: if (nextlen == 0) max_count = 138, min_count = 3; 5128eecc9f 2011-02-23 kinaba: tree[max_code+1].Len = (ush)0xffff; /* guard */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: for (n = 0; n <= max_code; n++) { 5128eecc9f 2011-02-23 kinaba: curlen = nextlen; nextlen = tree[n+1].Len; 5128eecc9f 2011-02-23 kinaba: if (++count < max_count && curlen == nextlen) { 5128eecc9f 2011-02-23 kinaba: continue; 5128eecc9f 2011-02-23 kinaba: } else if (count < min_count) { 5128eecc9f 2011-02-23 kinaba: s->bl_tree[curlen].Freq += count; 5128eecc9f 2011-02-23 kinaba: } else if (curlen != 0) { 5128eecc9f 2011-02-23 kinaba: if (curlen != prevlen) s->bl_tree[curlen].Freq++; 5128eecc9f 2011-02-23 kinaba: s->bl_tree[REP_3_6].Freq++; 5128eecc9f 2011-02-23 kinaba: } else if (count <= 10) { 5128eecc9f 2011-02-23 kinaba: s->bl_tree[REPZ_3_10].Freq++; 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: s->bl_tree[REPZ_11_138].Freq++; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: count = 0; prevlen = curlen; 5128eecc9f 2011-02-23 kinaba: if (nextlen == 0) { 5128eecc9f 2011-02-23 kinaba: max_count = 138, min_count = 3; 5128eecc9f 2011-02-23 kinaba: } else if (curlen == nextlen) { 5128eecc9f 2011-02-23 kinaba: max_count = 6, min_count = 3; 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: max_count = 7, min_count = 4; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Send a literal or distance tree in compressed form, using the codes in 5128eecc9f 2011-02-23 kinaba: * bl_tree. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void send_tree (s, tree, max_code) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: ct_data *tree; /* the tree to be scanned */ 5128eecc9f 2011-02-23 kinaba: int max_code; /* and its largest code of non zero frequency */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: int n; /* iterates over all tree elements */ 5128eecc9f 2011-02-23 kinaba: int prevlen = -1; /* last emitted length */ 5128eecc9f 2011-02-23 kinaba: int curlen; /* length of current code */ 5128eecc9f 2011-02-23 kinaba: int nextlen = tree[0].Len; /* length of next code */ 5128eecc9f 2011-02-23 kinaba: int count = 0; /* repeat count of the current code */ 5128eecc9f 2011-02-23 kinaba: int max_count = 7; /* max repeat count */ 5128eecc9f 2011-02-23 kinaba: int min_count = 4; /* min repeat count */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* tree[max_code+1].Len = -1; */ /* guard already set */ 5128eecc9f 2011-02-23 kinaba: if (nextlen == 0) max_count = 138, min_count = 3; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: for (n = 0; n <= max_code; n++) { 5128eecc9f 2011-02-23 kinaba: curlen = nextlen; nextlen = tree[n+1].Len; 5128eecc9f 2011-02-23 kinaba: if (++count < max_count && curlen == nextlen) { 5128eecc9f 2011-02-23 kinaba: continue; 5128eecc9f 2011-02-23 kinaba: } else if (count < min_count) { 5128eecc9f 2011-02-23 kinaba: do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: } else if (curlen != 0) { 5128eecc9f 2011-02-23 kinaba: if (curlen != prevlen) { 5128eecc9f 2011-02-23 kinaba: send_code(s, curlen, s->bl_tree); count--; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: Assert(count >= 3 && count <= 6, " 3_6?"); 5128eecc9f 2011-02-23 kinaba: send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: } else if (count <= 10) { 5128eecc9f 2011-02-23 kinaba: send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: count = 0; prevlen = curlen; 5128eecc9f 2011-02-23 kinaba: if (nextlen == 0) { 5128eecc9f 2011-02-23 kinaba: max_count = 138, min_count = 3; 5128eecc9f 2011-02-23 kinaba: } else if (curlen == nextlen) { 5128eecc9f 2011-02-23 kinaba: max_count = 6, min_count = 3; 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: max_count = 7, min_count = 4; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Construct the Huffman tree for the bit lengths and return the index in 5128eecc9f 2011-02-23 kinaba: * bl_order of the last bit length code to send. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local int build_bl_tree(s) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: int max_blindex; /* index of last bit length code of non zero freq */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Determine the bit length frequencies for literal and distance trees */ 5128eecc9f 2011-02-23 kinaba: scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 5128eecc9f 2011-02-23 kinaba: scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Build the bit length tree: */ 5128eecc9f 2011-02-23 kinaba: build_tree(s, (tree_desc *)(&(s->bl_desc))); 5128eecc9f 2011-02-23 kinaba: /* opt_len now includes the length of the tree representations, except 5128eecc9f 2011-02-23 kinaba: * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Determine the number of bit length codes to send. The pkzip format 5128eecc9f 2011-02-23 kinaba: * requires that at least 4 bit length codes be sent. (appnote.txt says 5128eecc9f 2011-02-23 kinaba: * 3 but the actual value used is 4.) 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 5128eecc9f 2011-02-23 kinaba: if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: /* Update opt_len to include the bit length tree and counts */ 5128eecc9f 2011-02-23 kinaba: s->opt_len += 3*(max_blindex+1) + 5+5+4; 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 5128eecc9f 2011-02-23 kinaba: s->opt_len, s->static_len)); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: return max_blindex; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Send the header for a block using dynamic Huffman trees: the counts, the 5128eecc9f 2011-02-23 kinaba: * lengths of the bit length codes, the literal tree and the distance tree. 5128eecc9f 2011-02-23 kinaba: * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void send_all_trees(s, lcodes, dcodes, blcodes) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: int lcodes, dcodes, blcodes; /* number of codes for each tree */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: int rank; /* index in bl_order */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 5128eecc9f 2011-02-23 kinaba: Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 5128eecc9f 2011-02-23 kinaba: "too many codes"); 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\nbl counts: ")); 5128eecc9f 2011-02-23 kinaba: send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 5128eecc9f 2011-02-23 kinaba: send_bits(s, dcodes-1, 5); 5128eecc9f 2011-02-23 kinaba: send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 5128eecc9f 2011-02-23 kinaba: for (rank = 0; rank < blcodes; rank++) { 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 5128eecc9f 2011-02-23 kinaba: send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Send a stored block 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: void _tr_stored_block(s, buf, stored_len, eof) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: charf *buf; /* input block */ 5128eecc9f 2011-02-23 kinaba: ulg stored_len; /* length of input block */ 5128eecc9f 2011-02-23 kinaba: int eof; /* true if this is the last block for a file */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; 5128eecc9f 2011-02-23 kinaba: s->compressed_len += (stored_len + 4) << 3; 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Send one empty static block to give enough lookahead for inflate. 5128eecc9f 2011-02-23 kinaba: * This takes 10 bits, of which 7 may remain in the bit buffer. 5128eecc9f 2011-02-23 kinaba: * The current inflate code requires 9 bits of lookahead. If the 5128eecc9f 2011-02-23 kinaba: * last two codes for the previous block (real code plus EOB) were coded 5128eecc9f 2011-02-23 kinaba: * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode 5128eecc9f 2011-02-23 kinaba: * the last real code. In this case we send two empty static blocks instead 5128eecc9f 2011-02-23 kinaba: * of one. (There are no problems if the previous block is stored or fixed.) 5128eecc9f 2011-02-23 kinaba: * To simplify the code, we assume the worst case of last real code encoded 5128eecc9f 2011-02-23 kinaba: * on one bit only. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: void _tr_align(s) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: send_bits(s, STATIC_TREES<<1, 3); 5128eecc9f 2011-02-23 kinaba: send_code(s, END_BLOCK, static_ltree); 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: bi_flush(s); 5128eecc9f 2011-02-23 kinaba: /* Of the 10 bits for the empty block, we have already sent 5128eecc9f 2011-02-23 kinaba: * (10 - bi_valid) bits. The lookahead for the last real code (before 5128eecc9f 2011-02-23 kinaba: * the EOB of the previous block) was thus at least one plus the length 5128eecc9f 2011-02-23 kinaba: * of the EOB plus what we have just sent of the empty static block. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: if (1 + s->last_eob_len + 10 - s->bi_valid < 9) { 5128eecc9f 2011-02-23 kinaba: send_bits(s, STATIC_TREES<<1, 3); 5128eecc9f 2011-02-23 kinaba: send_code(s, END_BLOCK, static_ltree); 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->compressed_len += 10L; 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: bi_flush(s); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: s->last_eob_len = 7; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Determine the best encoding for the current block: dynamic trees, static 5128eecc9f 2011-02-23 kinaba: * trees or store, and output the encoded block to the zip file. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: void _tr_flush_block(s, buf, stored_len, eof) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: charf *buf; /* input block, or NULL if too old */ 5128eecc9f 2011-02-23 kinaba: ulg stored_len; /* length of input block */ 5128eecc9f 2011-02-23 kinaba: int eof; /* true if this is the last block for a file */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 5128eecc9f 2011-02-23 kinaba: int max_blindex = 0; /* index of last bit length code of non zero freq */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Build the Huffman trees unless a stored block is forced */ 5128eecc9f 2011-02-23 kinaba: if (s->level > 0) { 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Check if the file is ascii or binary */ 5128eecc9f 2011-02-23 kinaba: if (s->data_type == Z_UNKNOWN) set_data_type(s); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Construct the literal and distance trees */ 5128eecc9f 2011-02-23 kinaba: build_tree(s, (tree_desc *)(&(s->l_desc))); 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 5128eecc9f 2011-02-23 kinaba: s->static_len)); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: build_tree(s, (tree_desc *)(&(s->d_desc))); 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 5128eecc9f 2011-02-23 kinaba: s->static_len)); 5128eecc9f 2011-02-23 kinaba: /* At this point, opt_len and static_len are the total bit lengths of 5128eecc9f 2011-02-23 kinaba: * the compressed block data, excluding the tree representations. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Build the bit length tree for the above two trees, and get the index 5128eecc9f 2011-02-23 kinaba: * in bl_order of the last bit length code to send. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: max_blindex = build_bl_tree(s); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Determine the best encoding. Compute first the block length in bytes*/ 5128eecc9f 2011-02-23 kinaba: opt_lenb = (s->opt_len+3+7)>>3; 5128eecc9f 2011-02-23 kinaba: static_lenb = (s->static_len+3+7)>>3; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 5128eecc9f 2011-02-23 kinaba: opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 5128eecc9f 2011-02-23 kinaba: s->last_lit)); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: Assert(buf != (char*)0, "lost buf"); 5128eecc9f 2011-02-23 kinaba: opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #ifdef FORCE_STORED 5128eecc9f 2011-02-23 kinaba: if (buf != (char*)0) { /* force stored block */ 5128eecc9f 2011-02-23 kinaba: #else 5128eecc9f 2011-02-23 kinaba: if (stored_len+4 <= opt_lenb && buf != (char*)0) { 5128eecc9f 2011-02-23 kinaba: /* 4: two words for the lengths */ 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 5128eecc9f 2011-02-23 kinaba: * Otherwise we can't have processed more than WSIZE input bytes since 5128eecc9f 2011-02-23 kinaba: * the last block flush, because compression would have been 5128eecc9f 2011-02-23 kinaba: * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 5128eecc9f 2011-02-23 kinaba: * transform a block into a stored block. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: _tr_stored_block(s, buf, stored_len, eof); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #ifdef FORCE_STATIC 5128eecc9f 2011-02-23 kinaba: } else if (static_lenb >= 0) { /* force static trees */ 5128eecc9f 2011-02-23 kinaba: #else 5128eecc9f 2011-02-23 kinaba: } else if (static_lenb == opt_lenb) { 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: send_bits(s, (STATIC_TREES<<1)+eof, 3); 5128eecc9f 2011-02-23 kinaba: compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->compressed_len += 3 + s->static_len; 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: send_bits(s, (DYN_TREES<<1)+eof, 3); 5128eecc9f 2011-02-23 kinaba: send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 5128eecc9f 2011-02-23 kinaba: max_blindex+1); 5128eecc9f 2011-02-23 kinaba: compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->compressed_len += 3 + s->opt_len; 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 5128eecc9f 2011-02-23 kinaba: /* The above check is made mod 2^32, for files larger than 512 MB 5128eecc9f 2011-02-23 kinaba: * and uLong implemented on 32 bits. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: init_block(s); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: if (eof) { 5128eecc9f 2011-02-23 kinaba: bi_windup(s); 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->compressed_len += 7; /* align on byte boundary */ 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 5128eecc9f 2011-02-23 kinaba: s->compressed_len-7*eof)); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Save the match info and tally the frequency counts. Return true if 5128eecc9f 2011-02-23 kinaba: * the current block must be flushed. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: int _tr_tally (s, dist, lc) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: unsigned dist; /* distance of matched string */ 5128eecc9f 2011-02-23 kinaba: unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: s->d_buf[s->last_lit] = (ush)dist; 5128eecc9f 2011-02-23 kinaba: s->l_buf[s->last_lit++] = (uch)lc; 5128eecc9f 2011-02-23 kinaba: if (dist == 0) { 5128eecc9f 2011-02-23 kinaba: /* lc is the unmatched char */ 5128eecc9f 2011-02-23 kinaba: s->dyn_ltree[lc].Freq++; 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: s->matches++; 5128eecc9f 2011-02-23 kinaba: /* Here, lc is the match length - MIN_MATCH */ 5128eecc9f 2011-02-23 kinaba: dist--; /* dist = match distance - 1 */ 5128eecc9f 2011-02-23 kinaba: Assert((ush)dist < (ush)MAX_DIST(s) && 5128eecc9f 2011-02-23 kinaba: (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 5128eecc9f 2011-02-23 kinaba: (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++; 5128eecc9f 2011-02-23 kinaba: s->dyn_dtree[d_code(dist)].Freq++; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: #ifdef TRUNCATE_BLOCK 5128eecc9f 2011-02-23 kinaba: /* Try to guess if it is profitable to stop the current block here */ 5128eecc9f 2011-02-23 kinaba: if ((s->last_lit & 0x1fff) == 0 && s->level > 2) { 5128eecc9f 2011-02-23 kinaba: /* Compute an upper bound for the compressed length */ 5128eecc9f 2011-02-23 kinaba: ulg out_length = (ulg)s->last_lit*8L; 5128eecc9f 2011-02-23 kinaba: ulg in_length = (ulg)((long)s->strstart - s->block_start); 5128eecc9f 2011-02-23 kinaba: int dcode; 5128eecc9f 2011-02-23 kinaba: for (dcode = 0; dcode < D_CODES; dcode++) { 5128eecc9f 2011-02-23 kinaba: out_length += (ulg)s->dyn_dtree[dcode].Freq * 5128eecc9f 2011-02-23 kinaba: (5L+extra_dbits[dcode]); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: out_length >>= 3; 5128eecc9f 2011-02-23 kinaba: Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 5128eecc9f 2011-02-23 kinaba: s->last_lit, in_length, out_length, 5128eecc9f 2011-02-23 kinaba: 100L - out_length*100L/in_length)); 5128eecc9f 2011-02-23 kinaba: if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: return (s->last_lit == s->lit_bufsize-1); 5128eecc9f 2011-02-23 kinaba: /* We avoid equality with lit_bufsize because of wraparound at 64K 5128eecc9f 2011-02-23 kinaba: * on 16 bit machines and because stored blocks are restricted to 5128eecc9f 2011-02-23 kinaba: * 64K-1 bytes. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Send the block data compressed using the given Huffman trees 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void compress_block(s, ltree, dtree) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: ct_data *ltree; /* literal tree */ 5128eecc9f 2011-02-23 kinaba: ct_data *dtree; /* distance tree */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: unsigned dist; /* distance of matched string */ 5128eecc9f 2011-02-23 kinaba: int lc; /* match length or unmatched char (if dist == 0) */ 5128eecc9f 2011-02-23 kinaba: unsigned lx = 0; /* running index in l_buf */ 5128eecc9f 2011-02-23 kinaba: unsigned code; /* the code to send */ 5128eecc9f 2011-02-23 kinaba: int extra; /* number of extra bits to send */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: if (s->last_lit != 0) do { 5128eecc9f 2011-02-23 kinaba: dist = s->d_buf[lx]; 5128eecc9f 2011-02-23 kinaba: lc = s->l_buf[lx++]; 5128eecc9f 2011-02-23 kinaba: if (dist == 0) { 5128eecc9f 2011-02-23 kinaba: send_code(s, lc, ltree); /* send a literal byte */ 5128eecc9f 2011-02-23 kinaba: Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 5128eecc9f 2011-02-23 kinaba: } else { 5128eecc9f 2011-02-23 kinaba: /* Here, lc is the match length - MIN_MATCH */ 5128eecc9f 2011-02-23 kinaba: code = _length_code[lc]; 5128eecc9f 2011-02-23 kinaba: send_code(s, code+LITERALS+1, ltree); /* send the length code */ 5128eecc9f 2011-02-23 kinaba: extra = extra_lbits[code]; 5128eecc9f 2011-02-23 kinaba: if (extra != 0) { 5128eecc9f 2011-02-23 kinaba: lc -= base_length[code]; 5128eecc9f 2011-02-23 kinaba: send_bits(s, lc, extra); /* send the extra length bits */ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: dist--; /* dist is now the match distance - 1 */ 5128eecc9f 2011-02-23 kinaba: code = d_code(dist); 5128eecc9f 2011-02-23 kinaba: Assert (code < D_CODES, "bad d_code"); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: send_code(s, code, dtree); /* send the distance code */ 5128eecc9f 2011-02-23 kinaba: extra = extra_dbits[code]; 5128eecc9f 2011-02-23 kinaba: if (extra != 0) { 5128eecc9f 2011-02-23 kinaba: dist -= base_dist[code]; 5128eecc9f 2011-02-23 kinaba: send_bits(s, dist, extra); /* send the extra distance bits */ 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } /* literal or match pair ? */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 5128eecc9f 2011-02-23 kinaba: Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: } while (lx < s->last_lit); 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: send_code(s, END_BLOCK, ltree); 5128eecc9f 2011-02-23 kinaba: s->last_eob_len = ltree[END_BLOCK].Len; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Set the data type to ASCII or BINARY, using a crude approximation: 5128eecc9f 2011-02-23 kinaba: * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 5128eecc9f 2011-02-23 kinaba: * IN assertion: the fields freq of dyn_ltree are set and the total of all 5128eecc9f 2011-02-23 kinaba: * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void set_data_type(s) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: int n = 0; 5128eecc9f 2011-02-23 kinaba: unsigned ascii_freq = 0; 5128eecc9f 2011-02-23 kinaba: unsigned bin_freq = 0; 5128eecc9f 2011-02-23 kinaba: while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 5128eecc9f 2011-02-23 kinaba: while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 5128eecc9f 2011-02-23 kinaba: while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 5128eecc9f 2011-02-23 kinaba: s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Reverse the first len bits of a code, using straightforward code (a faster 5128eecc9f 2011-02-23 kinaba: * method would use a table) 5128eecc9f 2011-02-23 kinaba: * IN assertion: 1 <= len <= 15 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local unsigned bi_reverse(code, len) 5128eecc9f 2011-02-23 kinaba: unsigned code; /* the value to invert */ 5128eecc9f 2011-02-23 kinaba: int len; /* its bit length */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: register unsigned res = 0; 5128eecc9f 2011-02-23 kinaba: do { 5128eecc9f 2011-02-23 kinaba: res |= code & 1; 5128eecc9f 2011-02-23 kinaba: code >>= 1, res <<= 1; 5128eecc9f 2011-02-23 kinaba: } while (--len > 0); 5128eecc9f 2011-02-23 kinaba: return res >> 1; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Flush the bit buffer, keeping at most 7 bits in it. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void bi_flush(s) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: if (s->bi_valid == 16) { 5128eecc9f 2011-02-23 kinaba: put_short(s, s->bi_buf); 5128eecc9f 2011-02-23 kinaba: s->bi_buf = 0; 5128eecc9f 2011-02-23 kinaba: s->bi_valid = 0; 5128eecc9f 2011-02-23 kinaba: } else if (s->bi_valid >= 8) { 5128eecc9f 2011-02-23 kinaba: put_byte(s, (Byte)s->bi_buf); 5128eecc9f 2011-02-23 kinaba: s->bi_buf >>= 8; 5128eecc9f 2011-02-23 kinaba: s->bi_valid -= 8; 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Flush the bit buffer and align the output on a byte boundary 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void bi_windup(s) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: if (s->bi_valid > 8) { 5128eecc9f 2011-02-23 kinaba: put_short(s, s->bi_buf); 5128eecc9f 2011-02-23 kinaba: } else if (s->bi_valid > 0) { 5128eecc9f 2011-02-23 kinaba: put_byte(s, (Byte)s->bi_buf); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: s->bi_buf = 0; 5128eecc9f 2011-02-23 kinaba: s->bi_valid = 0; 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->bits_sent = (s->bits_sent+7) & ~7; 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: /* =========================================================================== 5128eecc9f 2011-02-23 kinaba: * Copy a stored block, storing first the length and its 5128eecc9f 2011-02-23 kinaba: * one's complement if requested. 5128eecc9f 2011-02-23 kinaba: */ 5128eecc9f 2011-02-23 kinaba: local void copy_block(s, buf, len, header) 5128eecc9f 2011-02-23 kinaba: deflate_state *s; 5128eecc9f 2011-02-23 kinaba: charf *buf; /* the input data */ 5128eecc9f 2011-02-23 kinaba: unsigned len; /* its length */ 5128eecc9f 2011-02-23 kinaba: int header; /* true if block header must be written */ 5128eecc9f 2011-02-23 kinaba: { 5128eecc9f 2011-02-23 kinaba: bi_windup(s); /* align on byte boundary */ 5128eecc9f 2011-02-23 kinaba: s->last_eob_len = 8; /* enough lookahead for inflate */ 5128eecc9f 2011-02-23 kinaba: 5128eecc9f 2011-02-23 kinaba: if (header) { 5128eecc9f 2011-02-23 kinaba: put_short(s, (ush)len); 5128eecc9f 2011-02-23 kinaba: put_short(s, (ush)~len); 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->bits_sent += 2*16; 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: #ifdef DEBUG 5128eecc9f 2011-02-23 kinaba: s->bits_sent += (ulg)len<<3; 5128eecc9f 2011-02-23 kinaba: #endif 5128eecc9f 2011-02-23 kinaba: while (len--) { 5128eecc9f 2011-02-23 kinaba: put_byte(s, *buf++); 5128eecc9f 2011-02-23 kinaba: } 5128eecc9f 2011-02-23 kinaba: }