diff options
Diffstat (limited to 'pppdump/zlib.c')
| -rw-r--r-- | pppdump/zlib.c | 2465 |
1 files changed, 0 insertions, 2465 deletions
diff --git a/pppdump/zlib.c b/pppdump/zlib.c index c3c68f6..7b7dd63 100644 --- a/pppdump/zlib.c +++ b/pppdump/zlib.c @@ -129,2471 +129,6 @@ typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len)); (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size)) #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);} -/* deflate.h -- internal compression state - * Copyright (C) 1995 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. - */ - - -/*+++++*/ -/* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */ - -/* =========================================================================== - * Internal compression state. - */ - -/* Data type */ -#define BINARY 0 -#define ASCII 1 -#define UNKNOWN 2 - -#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 INIT_STATE 42 -#define BUSY_STATE 113 -#define FLUSH_STATE 124 -#define FINISH_STATE 666 -/* Stream status */ - - -/* Data structure describing a single value and its code string. */ -typedef struct ct_data_s { - union { - ush freq; /* frequency count */ - ush code; /* bit string */ - } fc; - union { - ush dad; /* father node in Huffman tree */ - ush len; /* length of bit string */ - } dl; -} FAR 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 */ - static_tree_desc *stat_desc; /* the corresponding static tree */ -} FAR tree_desc; - -typedef ush Pos; -typedef Pos FAR Posf; -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 deflate_state { - z_stream *strm; /* pointer back to this zlib stream */ - int status; /* as the name implies */ - Bytef *pending_buf; /* output still pending */ - Bytef *pending_out; /* next pending byte to output to the stream */ - int pending; /* nb of bytes in the pending buffer */ - uLong adler; /* adler32 of uncompressed data */ - int noheader; /* suppress zlib header and adler32 */ - Byte data_type; /* UNKNOWN, BINARY or ASCII */ - Byte method; /* STORED (for zip only) or DEFLATED */ - int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */ - - /* used by deflate.c: */ - - uInt w_size; /* LZ77 window size (32K by default) */ - uInt w_bits; /* log2(w_size) (8..16) */ - uInt w_mask; /* w_size - 1 */ - - Bytef *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. - */ - - ulg window_size; - /* Actual size of window: 2*wSize, except when the user input buffer - * is directly used as sliding window. - */ - - Posf *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. - */ - - Posf *head; /* Heads of the hash chains or NIL. */ - - uInt ins_h; /* hash index of string to be inserted */ - uInt hash_size; /* number of elements in hash table */ - uInt hash_bits; /* log2(hash_size) */ - uInt hash_mask; /* hash_size-1 */ - - uInt 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. - */ - - uInt match_length; /* length of best match */ - IPos prev_match; /* previous match */ - int match_available; /* set if previous match exists */ - uInt strstart; /* start of string to insert */ - uInt match_start; /* start of matching string */ - uInt lookahead; /* number of valid bytes ahead in window */ - - uInt 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. - */ - - uInt 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. - */ - - uInt 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*/ - - uInt 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 supress 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 */ - - ush 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. - */ - - uch depth[2*L_CODES+1]; - /* Depth of each subtree used as tie breaker for trees of equal frequency - */ - - uchf *l_buf; /* buffer for literals or lengths */ - - uInt 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 - */ - - uInt last_lit; /* running index in l_buf */ - - ushf *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. - */ - - ulg opt_len; /* bit length of current block with optimal trees */ - ulg static_len; /* bit length of current block with static trees */ - ulg compressed_len; /* total bit length of compressed file */ - uInt matches; /* number of string matches in current block */ - int last_eob_len; /* bit length of EOB code for last block */ - -#ifdef DEBUG_ZLIB - ulg bits_sent; /* bit length of the compressed data */ -#endif - - ush 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. - */ - - uInt blocks_in_packet; - /* Number of blocks produced since the last time Z_PACKET_FLUSH - * was used. - */ - -} FAR deflate_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);} - - -#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. - */ - - /* in trees.c */ -local void ct_init OF((deflate_state *s)); -local int ct_tally OF((deflate_state *s, int dist, int lc)); -local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, - int flush)); -local void ct_align OF((deflate_state *s)); -local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, - int eof)); -local void ct_stored_type_only OF((deflate_state *s)); - - -/*+++++*/ -/* deflate.c -- compress data using the deflation algorithm - * Copyright (C) 1995 Jean-loup Gailly. - * For conditions of distribution and use, see copyright notice in zlib.h - */ - -/* - * ALGORITHM - * - * The "deflation" process depends on being able to identify portions - * of the input text which are identical to earlier input (within a - * sliding window trailing behind the input currently being processed). - * - * The most straightforward technique turns out to be the fastest for - * most input files: try all possible matches and select the longest. - * The key feature of this algorithm is that insertions into the string - * dictionary are very simple and thus fast, and deletions are avoided - * completely. Insertions are performed at each input character, whereas - * string matches are performed only when the previous match ends. So it - * is preferable to spend more time in matches to allow very fast string - * insertions and avoid deletions. The matching algorithm for small - * strings is inspired from that of Rabin & Karp. A brute force approach - * is used to find longer strings when a small match has been found. - * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze - * (by Leonid Broukhis). - * A previous version of this file used a more sophisticated algorithm - * (by Fiala and Greene) which is guaranteed to run in linear amortized - * time, but has a larger average cost, uses more memory and is patented. - * However the F&G algorithm may be faster for some highly redundant - * files if the parameter max_chain_length (described below) is too large. - * - * ACKNOWLEDGEMENTS - * - * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and - * I found it in 'freeze' written by Leonid Broukhis. - * Thanks to many people for bug reports and testing. - * - * REFERENCES - * - * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". - * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc - * - * A description of the Rabin and Karp algorithm is given in the book - * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. - * - * Fiala,E.R., and Greene,D.H. - * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 - * - */ - -/* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */ - -local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly "; -/* - If you use the zlib library in a product, an acknowledgment is welcome - in the documentation of your product. If for some reason you cannot - include such an acknowledgment, I would appreciate that you keep this - copyright string in the executable of your product. - */ - -#define NIL 0 -/* Tail of hash chains */ - -#ifndef TOO_FAR -# define TOO_FAR 4096 -#endif -/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ - -#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. - */ - -/* Values for max_lazy_match, good_match and max_chain_length, depending on - * the desired pack level (0..9). The values given below have been tuned to - * exclude worst case performance for pathological files. Better values may be - * found for specific files. - */ - -typedef struct config_s { - ush good_length; /* reduce lazy search above this match length */ - ush max_lazy; /* do not perform lazy search above this match length */ - ush nice_length; /* quit search above this match length */ - ush max_chain; -} config; - -local config configuration_table[10] = { -/* good lazy nice chain */ -/* 0 */ {0, 0, 0, 0}, /* store only */ -/* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */ -/* 2 */ {4, 5, 16, 8}, -/* 3 */ {4, 6, 32, 32}, - -/* 4 */ {4, 4, 16, 16}, /* lazy matches */ -/* 5 */ {8, 16, 32, 32}, -/* 6 */ {8, 16, 128, 128}, -/* 7 */ {8, 32, 128, 256}, -/* 8 */ {32, 128, 258, 1024}, -/* 9 */ {32, 258, 258, 4096}}; /* maximum compression */ - -/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 - * For deflate_fast() (levels <= 3) good is ignored and lazy has a different - * meaning. - */ - -#define EQUAL 0 -/* result of memcmp for equal strings */ - -/* =========================================================================== - * Prototypes for local functions. - */ - -local void fill_window OF((deflate_state *s)); -local int deflate_fast OF((deflate_state *s, int flush)); -local int deflate_slow OF((deflate_state *s, int flush)); -local void lm_init OF((deflate_state *s)); -local int longest_match OF((deflate_state *s, IPos cur_match)); -local void putShortMSB OF((deflate_state *s, uInt b)); -local void flush_pending OF((z_stream *strm)); -local int read_buf OF((z_stream *strm, charf *buf, unsigned size)); -#ifdef ASMV - void match_init OF((void)); /* asm code initialization */ -#endif - -#ifdef DEBUG_ZLIB -local void check_match OF((deflate_state *s, IPos start, IPos match, - int 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. - */ -#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) - - -/* =========================================================================== - * Insert string str in the dictionary and set match_head to the previous head - * of the hash chain (the most recent string with same hash key). Return - * the previous length of the hash chain. - * IN assertion: all calls to to INSERT_STRING are made with consecutive - * input characters and the first MIN_MATCH bytes of str are valid - * (except for the last MIN_MATCH-1 bytes of the input file). - */ -#define INSERT_STRING(s, str, match_head) \ - (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ - s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ - s->head[s->ins_h] = (str)) - -/* =========================================================================== - * Initialize the hash table (avoiding 64K overflow for 16 bit systems). - * prev[] will be initialized on the fly. - */ -#define CLEAR_HASH(s) \ - s->head[s->hash_size-1] = NIL; \ - zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); - -/* ========================================================================= */ -int deflateInit (strm, level) - z_stream *strm; - int level; -{ - return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, - 0, 0); - /* To do: ignore strm->next_in if we use it as window */ -} - -/* ========================================================================= */ -int deflateInit2 (strm, level, method, windowBits, memLevel, - strategy, minCompression) - z_stream *strm; - int level; - int method; - int windowBits; - int memLevel; - int strategy; - int minCompression; -{ - deflate_state *s; - int noheader = 0; - - if (strm == Z_NULL) return Z_STREAM_ERROR; - - strm->msg = Z_NULL; -/* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */ -/* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */ - - if (level == Z_DEFAULT_COMPRESSION) level = 6; - - if (windowBits < 0) { /* undocumented feature: suppress zlib header */ - noheader = 1; - windowBits = -windowBits; - } - if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED || - windowBits < 8 || windowBits > 15 || level < 1 || level > 9) { - return Z_STREAM_ERROR; - } - s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); - if (s == Z_NULL) return Z_MEM_ERROR; - strm->state = (struct internal_state FAR *)s; - s->strm = strm; - - s->noheader = noheader; - s->w_bits = windowBits; - s->w_size = 1 << s->w_bits; - s->w_mask = s->w_size - 1; - - s->hash_bits = memLevel + 7; - s->hash_size = 1 << s->hash_bits; - s->hash_mask = s->hash_size - 1; - s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); - - s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); - s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); - s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); - - s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ - - s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush)); - - if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || - s->pending_buf == Z_NULL) { - strm->msg = z_errmsg[1-Z_MEM_ERROR]; - deflateEnd (strm); - return Z_MEM_ERROR; - } - s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]); - s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]); - /* We overlay pending_buf and d_buf+l_buf. This works since the average - * output size for (length,distance) codes is <= 32 bits (worst case - * is 15+15+13=33). - */ - - s->level = level; - s->strategy = strategy; - s->method = (Byte)method; - s->minCompr = minCompression; - s->blocks_in_packet = 0; - - return deflateReset(strm); -} - -/* ========================================================================= */ -int deflateReset (strm) - z_stream *strm; -{ - deflate_state *s; - - if (strm == Z_NULL || strm->state == Z_NULL || - strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; - - strm->total_in = strm->total_out = 0; - strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ - strm->data_type = Z_UNKNOWN; - - s = (deflate_state *)strm->state; - s->pending = 0; - s->pending_out = s->pending_buf; - - if (s->noheader < 0) { - s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ - } - s->status = s->noheader ? BUSY_STATE : INIT_STATE; - s->adler = 1; - - ct_init(s); - lm_init(s); - - return Z_OK; -} - -/* ========================================================================= - * Put a short in the pending buffer. The 16-bit value is put in MSB order. - * IN assertion: the stream state is correct and there is enough room in - * pending_buf. - */ -local void putShortMSB (s, b) - deflate_state *s; - uInt b; -{ - put_byte(s, (Byte)(b >> 8)); - put_byte(s, (Byte)(b & 0xff)); -} - -/* ========================================================================= - * Flush as much pending output as possible. - */ -local void flush_pending(strm) - z_stream *strm; -{ - deflate_state *state = (deflate_state *) strm->state; - unsigned len = state->pending; - - if (len > strm->avail_out) len = strm->avail_out; - if (len == 0) return; - - if (strm->next_out != NULL) { - zmemcpy(strm->next_out, state->pending_out, len); - strm->next_out += len; - } - state->pending_out += len; - strm->total_out += len; - strm->avail_out -= len; - state->pending -= len; - if (state->pending == 0) { - state->pending_out = state->pending_buf; - } -} - -/* ========================================================================= */ -int deflate (strm, flush) - z_stream *strm; - int flush; -{ - deflate_state *state = (deflate_state *) strm->state; - - if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR; - - if (strm->next_in == Z_NULL && strm->avail_in != 0) { - ERR_RETURN(strm, Z_STREAM_ERROR); - } - if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); - - state->strm = strm; /* just in case */ - - /* Write the zlib header */ - if (state->status == INIT_STATE) { - - uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8; - uInt level_flags = (state->level-1) >> 1; - - if (level_flags > 3) level_flags = 3; - header |= (level_flags << 6); - header += 31 - (header % 31); - - state->status = BUSY_STATE; - putShortMSB(state, header); - } - - /* Flush as much pending output as possible */ - if (state->pending != 0) { - flush_pending(strm); - if (strm->avail_out == 0) return Z_OK; - } - - /* If we came back in here to get the last output from - * a previous flush, we're done for now. - */ - if (state->status == FLUSH_STATE) { - state->status = BUSY_STATE; - if (flush != Z_NO_FLUSH && flush != Z_FINISH) - return Z_OK; - } - - /* User must not provide more input after the first FINISH: */ - if (state->status == FINISH_STATE && strm->avail_in != 0) { - ERR_RETURN(strm, Z_BUF_ERROR); - } - - /* Start a new block or continue the current one. - */ - if (strm->avail_in != 0 || state->lookahead != 0 || - (flush == Z_FINISH && state->status != FINISH_STATE)) { - int quit; - - if (flush == Z_FINISH) { - state->status = FINISH_STATE; - } - if (state->level <= 3) { - quit = deflate_fast(state, flush); - } else { - quit = deflate_slow(state, flush); - } - if (quit || strm->avail_out == 0) - return Z_OK; - /* If flush != Z_NO_FLUSH && avail_out == 0, the next call - * of deflate should use the same flush parameter to make sure - * that the flush is complete. So we don't have to output an - * empty block here, this will be done at next call. This also - * ensures that for a very small output buffer, we emit at most - * one empty block. - */ - } - - /* If a flush was requested, we have a little more to output now. */ - if (flush != Z_NO_FLUSH && flush != Z_FINISH - && state->status != FINISH_STATE) { - switch (flush) { - case Z_PARTIAL_FLUSH: - ct_align(state); - break; - case Z_PACKET_FLUSH: - /* Output just the 3-bit `stored' block type value, - but not a zero length. */ - ct_stored_type_only(state); - break; - default: - ct_stored_block(state, (char*)0, 0L, 0); - /* For a full flush, this empty block will be recognized - * as a special marker by inflate_sync(). - */ - if (flush == Z_FULL_FLUSH) { - CLEAR_HASH(state); /* forget history */ - } - } - flush_pending(strm); - if (strm->avail_out == 0) { - /* We'll have to come back to get the rest of the output; - * this ensures we don't output a second zero-length stored - * block (or whatever). - */ - state->status = FLUSH_STATE; - return Z_OK; - } - } - - Assert(strm->avail_out > 0, "bug2"); - - if (flush != Z_FINISH) return Z_OK; - if (state->noheader) return Z_STREAM_END; - - /* Write the zlib trailer (adler32) */ - putShortMSB(state, (uInt)(state->adler >> 16)); - putShortMSB(state, (uInt)(state->adler & 0xffff)); - flush_pending(strm); - /* If avail_out is zero, the application will call deflate again - * to flush the rest. - */ - state->noheader = -1; /* write the trailer only once! */ - return state->pending != 0 ? Z_OK : Z_STREAM_END; -} - -/* ========================================================================= */ -int deflateEnd (strm) - z_stream *strm; -{ - deflate_state *state = (deflate_state *) strm->state; - - if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR; - - TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte)); - TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos)); - TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos)); - TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush)); - - ZFREE(strm, state, sizeof(deflate_state)); - strm->state = Z_NULL; - - return Z_OK; -} - -/* =========================================================================== - * Read a new buffer from the current input stream, update the adler32 - * and total number of bytes read. - */ -local int read_buf(strm, buf, size) - z_stream *strm; - charf *buf; - unsigned size; -{ - unsigned len = strm->avail_in; - deflate_state *state = (deflate_state *) strm->state; - - if (len > size) len = size; - if (len == 0) return 0; - - strm->avail_in -= len; - - if (!state->noheader) { - state->adler = adler32(state->adler, strm->next_in, len); - } - zmemcpy(buf, strm->next_in, len); - strm->next_in += len; - strm->total_in += len; - - return (int)len; -} - -/* =========================================================================== - * Initialize the "longest match" routines for a new zlib stream - */ -local void lm_init (s) - deflate_state *s; -{ - s->window_size = (ulg)2L*s->w_size; - - CLEAR_HASH(s); - - /* Set the default configuration parameters: - */ - s->max_lazy_match = configuration_table[s->level].max_lazy; - s->good_match = configuration_table[s->level].good_length; - s->nice_match = configuration_table[s->level].nice_length; - s->max_chain_length = configuration_table[s->level].max_chain; - - s->strstart = 0; - s->block_start = 0L; - s->lookahead = 0; - s->match_length = MIN_MATCH-1; - s->match_available = 0; - s->ins_h = 0; -#ifdef ASMV - match_init(); /* initialize the asm code */ -#endif -} - -/* =========================================================================== - * Set match_start to the longest match starting at the given string and - * return its length. Matches shorter or equal to prev_length are discarded, - * in which case the result is equal to prev_length and match_start is - * garbage. - * IN assertions: cur_match is the head of the hash chain for the current - * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 - */ -#ifndef ASMV -/* For 80x86 and 680x0, an optimized version will be provided in match.asm or - * match.S. The code will be functionally equivalent. - */ -local int longest_match(s, cur_match) - deflate_state *s; - IPos cur_match; /* current match */ -{ - unsigned chain_length = s->max_chain_length;/* max hash chain length */ - register Bytef *scan = s->window + s->strstart; /* current string */ - register Bytef *match; /* matched string */ - register int len; /* length of current match */ - int best_len = s->prev_length; /* best match length so far */ - IPos limit = s->strstart > (IPos)MAX_DIST(s) ? - s->strstart - (IPos)MAX_DIST(s) : NIL; - /* Stop when cur_match becomes <= limit. To simplify the code, - * we prevent matches with the string of window index 0. - */ - Posf *prev = s->prev; - uInt wmask = s->w_mask; - -#ifdef UNALIGNED_OK - /* Compare two bytes at a time. Note: this is not always beneficial. - * Try with and without -DUNALIGNED_OK to check. - */ - register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; - register ush scan_start = *(ushf*)scan; - register ush scan_end = *(ushf*)(scan+best_len-1); -#else - register Bytef *strend = s->window + s->strstart + MAX_MATCH; - register Byte scan_end1 = scan[best_len-1]; - register Byte scan_end = scan[best_len]; -#endif - - /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. - * It is easy to get rid of this optimization if necessary. - */ - Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); - - /* Do not waste too much time if we already have a good match: */ - if (s->prev_length >= s->good_match) { - chain_length >>= 2; - } - Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); - - do { - Assert(cur_match < s->strstart, "no future"); - match = s->window + cur_match; - - /* Skip to next match if the match length cannot increase - * or if the match length is less than 2: - */ -#if (defined(UNALIGNED_OK) && MAX_MATCH == 258) - /* This code assumes sizeof(unsigned short) == 2. Do not use - * UNALIGNED_OK if your compiler uses a different size. - */ - if (*(ushf*)(match+best_len-1) != scan_end || - *(ushf*)match != scan_start) continue; - - /* It is not necessary to compare scan[2] and match[2] since they are - * always equal when the other bytes match, given that the hash keys - * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at - * strstart+3, +5, ... up to strstart+257. We check for insufficient - * lookahead only every 4th comparison; the 128th check will be made - * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is - * necessary to put more guard bytes at the end of the window, or - * to check more often for insufficient lookahead. - */ - Assert(scan[2] == match[2], "scan[2]?"); - scan++, match++; - do { - } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && - *(ushf*)(scan+=2) == *(ushf*)(match+=2) && - *(ushf*)(scan+=2) == *(ushf*)(match+=2) && - *(ushf*)(scan+=2) == *(ushf*)(match+=2) && - scan < strend); - /* The funny "do {}" generates better code on most compilers */ - - /* Here, scan <= window+strstart+257 */ - Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); - if (*scan == *match) scan++; - - len = (MAX_MATCH - 1) - (int)(strend-scan); - scan = strend - (MAX_MATCH-1); - -#else /* UNALIGNED_OK */ - - if (match[best_len] != scan_end || - match[best_len-1] != scan_end1 || - *match != *scan || - *++match != scan[1]) continue; - - /* The check at best_len-1 can be removed because it will be made - * again later. (This heuristic is not always a win.) - * It is not necessary to compare scan[2] and match[2] since they - * are always equal when the other bytes match, given that - * the hash keys are equal and that HASH_BITS >= 8. - */ - scan += 2, match++; - Assert(*scan == *match, "match[2]?"); - - /* We check for insufficient lookahead only every 8th comparison; - * the 256th check will be made at strstart+258. - */ - do { - } while (*++scan == *++match && *++scan == *++match && - *++scan == *++match && *++scan == *++match && - *++scan == *++match && *++scan == *++match && - *++scan == *++match && *++scan == *++match && - scan < strend); - - Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); - - len = MAX_MATCH - (int)(strend - scan); - scan = strend - MAX_MATCH; - -#endif /* UNALIGNED_OK */ - - if (len > best_len) { - s->match_start = cur_match; - best_len = len; - if (len >= s->nice_match) break; -#ifdef UNALIGNED_OK - scan_end = *(ushf*)(scan+best_len-1); -#else - scan_end1 = scan[best_len-1]; - scan_end = scan[best_len]; -#endif - } - } while ((cur_match = prev[cur_match & wmask]) > limit - && --chain_length != 0); - - return best_len; -} -#endif /* ASMV */ - -#ifdef DEBUG_ZLIB -/* =========================================================================== - * Check that the match at match_start is indeed a match. - */ -local void check_match(s, start, match, length) - deflate_state *s; - IPos start, match; - int length; -{ - /* check that the match is indeed a match */ - if (memcmp((charf *)s->window + match, - (charf *)s->window + start, length) != EQUAL) { - fprintf(stderr, - " start %u, match %u, length %d\n", - start, match, length); - do { fprintf(stderr, "%c%c", s->window[match++], - s->window[start++]); } while (--length != 0); - z_error("invalid match"); - } - if (verbose > 1) { - fprintf(stderr,"\\[%d,%d]", start-match, length); - do { putc(s->window[start++], stderr); } while (--length != 0); - } -} -#else -# define check_match(s, start, match, length) -#endif - -/* =========================================================================== - * Fill the window when the lookahead becomes insufficient. - * Updates strstart and lookahead. - * - * IN assertion: lookahead < MIN_LOOKAHEAD - * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD - * At least one byte has been read, or avail_in == 0; reads are - * performed for at least two bytes (required for the zip translate_eol - * option -- not supported here). - */ -local void fill_window(s) - deflate_state *s; -{ - register unsigned n, m; - register Posf *p; - unsigned more; /* Amount of free space at the end of the window. */ - uInt wsize = s->w_size; - - do { - more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); - - /* Deal with !@#$% 64K limit: */ - if (more == 0 && s->strstart == 0 && s->lookahead == 0) { - more = wsize; - } else if (more == (unsigned)(-1)) { - /* Very unlikely, but possible on 16 bit machine if strstart == 0 - * and lookahead == 1 (input done one byte at time) - */ - more--; - - /* If the window is almost full and there is insufficient lookahead, - * move the upper half to the lower one to make room in the upper half. - */ - } else if (s->strstart >= wsize+MAX_DIST(s)) { - - /* By the IN assertion, the window is not empty so we can't confuse - * more == 0 with more == 64K on a 16 bit machine. - */ - zmemcpy((charf *)s->window, (charf *)s->window+wsize, - (unsigned)wsize); - s->match_start -= wsize; - s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ - - s->block_start -= (long) wsize; - - /* Slide the hash table (could be avoided with 32 bit values - at the expense of memory usage): - */ - n = s->hash_size; - p = &s->head[n]; - do { - m = *--p; - *p = (Pos)(m >= wsize ? m-wsize : NIL); - } while (--n); - - n = wsize; - p = &s->prev[n]; - do { - m = *--p; - *p = (Pos)(m >= wsize ? m-wsize : NIL); - /* If n is not on any hash chain, prev[n] is garbage but - * its value will never be used. - */ - } while (--n); - - more += wsize; - } - if (s->strm->avail_in == 0) return; - - /* If there was no sliding: - * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && - * more == window_size - lookahead - strstart - * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) - * => more >= window_size - 2*WSIZE + 2 - * In the BIG_MEM or MMAP case (not yet supported), - * window_size == input_size + MIN_LOOKAHEAD && - * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. - * Otherwise, window_size == 2*WSIZE so more >= 2. - * If there was sliding, more >= WSIZE. So in all cases, more >= 2. - */ - Assert(more >= 2, "more < 2"); - - n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, - more); - s->lookahead += n; - - /* Initialize the hash value now that we have some input: */ - if (s->lookahead >= MIN_MATCH) { - s->ins_h = s->window[s->strstart]; - UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); -#if MIN_MATCH != 3 - Call UPDATE_HASH() MIN_MATCH-3 more times -#endif - } - /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, - * but this is not important since only literal bytes will be emitted. - */ - - } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); -} - -/* =========================================================================== - * Flush the current block, with given end-of-file flag. - * IN assertion: strstart is set to the end of the current match. - */ -#define FLUSH_BLOCK_ONLY(s, flush) { \ - ct_flush_block(s, (s->block_start >= 0L ? \ - (charf *)&s->window[(unsigned)s->block_start] : \ - (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \ - s->block_start = s->strstart; \ - flush_pending(s->strm); \ - Tracev((stderr,"[FLUSH]")); \ -} - -/* Same but force premature exit if necessary. */ -#define FLUSH_BLOCK(s, flush) { \ - FLUSH_BLOCK_ONLY(s, flush); \ - if (s->strm->avail_out == 0) return 1; \ -} - -/* =========================================================================== - * Compress as much as possible from the input stream, return true if - * processing was terminated prematurely (no more input or output space). - * This function does not perform lazy evaluationof matches and inserts - * new strings in the dictionary only for unmatched strings or for short - * matches. It is used only for the fast compression options. - */ -local int deflate_fast(s, flush) - deflate_state *s; - int flush; -{ - IPos hash_head = NIL; /* head of the hash chain */ - int bflush; /* set if current block must be flushed */ - - s->prev_length = MIN_MATCH-1; - - for (;;) { - /* Make sure that we always have enough lookahead, except - * at the end of the input file. We need MAX_MATCH bytes - * for the next match, plus MIN_MATCH bytes to insert the - * string following the next match. - */ - if (s->lookahead < MIN_LOOKAHEAD) { - fill_window(s); - if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; - - if (s->lookahead == 0) break; /* flush the current block */ - } - - /* Insert the string window[strstart .. strstart+2] in the - * dictionary, and set hash_head to the head of the hash chain: - */ - if (s->lookahead >= MIN_MATCH) { - INSERT_STRING(s, s->strstart, hash_head); - } - - /* Find the longest match, discarding those <= prev_length. - * At this point we have always match_length < MIN_MATCH - */ - if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { - /* To simplify the code, we prevent matches with the string - * of window index 0 (in particular we have to avoid a match - * of the string with itself at the start of the input file). - */ - if (s->strategy != Z_HUFFMAN_ONLY) { - s->match_length = longest_match (s, hash_head); - } - /* longest_match() sets match_start */ - - if (s->match_length > s->lookahead) s->match_length = s->lookahead; - } - if (s->match_length >= MIN_MATCH) { - check_match(s, s->strstart, s->match_start, s->match_length); - - bflush = ct_tally(s, s->strstart - s->match_start, - s->match_length - MIN_MATCH); - - s->lookahead -= s->match_length; - - /* Insert new strings in the hash table only if the match length - * is not too large. This saves time but degrades compression. - */ - if (s->match_length <= s->max_insert_length && - s->lookahead >= MIN_MATCH) { - s->match_length--; /* string at strstart already in hash table */ - do { - s->strstart++; - INSERT_STRING(s, s->strstart, hash_head); - /* strstart never exceeds WSIZE-MAX_MATCH, so there are - * always MIN_MATCH bytes ahead. - */ - } while (--s->match_length != 0); - s->strstart++; - } else { - s->strstart += s->match_length; - s->match_length = 0; - s->ins_h = s->window[s->strstart]; - UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); -#if MIN_MATCH != 3 - Call UPDATE_HASH() MIN_MATCH-3 more times -#endif - /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not - * matter since it will be recomputed at next deflate call. - */ - } - } else { - /* No match, output a literal byte */ - Tracevv((stderr,"%c", s->window[s->strstart])); - bflush = ct_tally (s, 0, s->window[s->strstart]); - s->lookahead--; - s->strstart++; - } - if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH); - } - FLUSH_BLOCK(s, flush); - return 0; /* normal exit */ -} - -/* =========================================================================== - * Same as above, but achieves better compression. We use a lazy - * evaluation for matches: a match is finally adopted only if there is - * no better match at the next window position. - */ -local int deflate_slow(s, flush) - deflate_state *s; - int flush; -{ - IPos hash_head = NIL; /* head of hash chain */ - int bflush; /* set if current block must be flushed */ - - /* Process the input block. */ - for (;;) { - /* Make sure that we always have enough lookahead, except - * at the end of the input file. We need MAX_MATCH bytes - * for the next match, plus MIN_MATCH bytes to insert the - * string following the next match. - */ - if (s->lookahead < MIN_LOOKAHEAD) { - fill_window(s); - if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; - - if (s->lookahead == 0) break; /* flush the current block */ - } - - /* Insert the string window[strstart .. strstart+2] in the - * dictionary, and set hash_head to the head of the hash chain: - */ - if (s->lookahead >= MIN_MATCH) { - INSERT_STRING(s, s->strstart, hash_head); - } - - /* Find the longest match, discarding those <= prev_length. - */ - s->prev_length = s->match_length, s->prev_match = s->match_start; - s->match_length = MIN_MATCH-1; - - if (hash_head != NIL && s->prev_length < s->max_lazy_match && - s->strstart - hash_head <= MAX_DIST(s)) { - /* To simplify the code, we prevent matches with the string - * of window index 0 (in particular we have to avoid a match - * of the string with itself at the start of the input file). - */ - if (s->strategy != Z_HUFFMAN_ONLY) { - s->match_length = longest_match (s, hash_head); - } - /* longest_match() sets match_start */ - if (s->match_length > s->lookahead) s->match_length = s->lookahead; - - if (s->match_length <= 5 && (s->strategy == Z_FILTERED || - (s->match_length == MIN_MATCH && - s->strstart - s->match_start > TOO_FAR))) { - - /* If prev_match is also MIN_MATCH, match_start is garbage - * but we will ignore the current match anyway. - */ - s->match_length = MIN_MATCH-1; - } - } - /* If there was a match at the previous step and the current - * match is not better, output the previous match: - */ - if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { - uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; - /* Do not insert strings in hash table beyond this. */ - - check_match(s, s->strstart-1, s->prev_match, s->prev_length); - - bflush = ct_tally(s, s->strstart -1 - s->prev_match, - s->prev_length - MIN_MATCH); - - /* Insert in hash table all strings up to the end of the match. - * strstart-1 and strstart are already inserted. If there is not - * enough lookahead, the last two strings are not inserted in - * the hash table. - */ - s->lookahead -= s->prev_length-1; - s->prev_length -= 2; - do { - if (++s->strstart <= max_insert) { - INSERT_STRING(s, s->strstart, hash_head); - } - } while (--s->prev_length != 0); - s->match_available = 0; - s->match_length = MIN_MATCH-1; - s->strstart++; - - if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH); - - } else if (s->match_available) { - /* If there was no match at the previous position, output a - * single literal. If there was a match but the current match - * is longer, truncate the previous match to a single literal. - */ - Tracevv((stderr,"%c", s->window[s->strstart-1])); - if (ct_tally (s, 0, s->window[s->strstart-1])) { - FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH); - } - s->strstart++; - s->lookahead--; - if (s->strm->avail_out == 0) return 1; - } else { - /* There is no previous match to compare with, wait for - * the next step to decide. - */ - s->match_available = 1; - s->strstart++; - s->lookahead--; - } - } - Assert (flush != Z_NO_FLUSH, "no flush?"); - if (s->match_available) { - Tracevv((stderr,"%c", s->window[s->strstart-1])); - ct_tally (s, 0, s->window[s->strstart-1]); - s->match_available = 0; - } - FLUSH_BLOCK(s, flush); - return 0; -} - - -/*+++++*/ -/* trees.c -- output deflated data using Huffman coding - * Copyright (C) 1995 Jean-loup Gailly - * For conditions of distribution and use, see copyright notice in zlib.h - */ - -/* - * ALGORITHM - * - * The "deflation" process uses several Huffman trees. The more - * common source values are represented by shorter bit sequences. - * - * Each code tree is stored in a compressed form which is itself - * a Huffman encoding of the lengths of all the code strings (in - * ascending order by source values). The actual code strings are - * reconstructed from the lengths in the inflate process, as described - * in the deflate specification. - * - * REFERENCES - * - * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". - * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc - * - * Storer, James A. - * Data Compression: Methods and Theory, pp. 49-50. - * Computer Science Press, 1988. ISBN 0-7167-8156-5. - * - * Sedgewick, R. - * Algorithms, p290. - * Addison-Wesley, 1983. ISBN 0-201-06672-6. - */ - -/* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */ - -#ifdef DEBUG_ZLIB -# include <ctype.h> -#endif - -/* =========================================================================== - * Constants - */ - -#define MAX_BL_BITS 7 -/* Bit length codes must not exceed MAX_BL_BITS bits */ - -#define END_BLOCK 256 -/* end of block literal code */ - -#define REP_3_6 16 -/* repeat previous bit length 3-6 times (2 bits of repeat count) */ - -#define REPZ_3_10 17 -/* repeat a zero length 3-10 times (3 bits of repeat count) */ - -#define REPZ_11_138 18 -/* repeat a zero length 11-138 times (7 bits of repeat count) */ - -local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ - = {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}; - -local int extra_dbits[D_CODES] /* extra bits for each distance code */ - = {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}; - -local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ - = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; - -local uch bl_order[BL_CODES] - = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; -/* The lengths of the bit length codes are sent in order of decreasing - * probability, to avoid transmitting the lengths for unused bit length codes. - */ - -#define Buf_size (8 * 2*sizeof(char)) -/* Number of bits used within bi_buf. (bi_buf might be implemented on - * more than 16 bits on some systems.) - */ - -/* =========================================================================== - * Local data. These are initialized only once. - * To do: initialize at compile time to be completely reentrant. ??? - */ - -local ct_data static_ltree[L_CODES+2]; -/* The static literal tree. Since the bit lengths are imposed, there is no - * need for the L_CODES extra codes used during heap construction. However - * The codes 286 and 287 are needed to build a canonical tree (see ct_init - * below). - */ - -local ct_data static_dtree[D_CODES]; -/* The static distance tree. (Actually a trivial tree since all codes use - * 5 bits.) - */ - -local uch dist_code[512]; -/* distance codes. The first 256 values correspond to the distances - * 3 .. 258, the last 256 values correspond to the top 8 bits of - * the 15 bit distances. - */ - -local uch length_code[MAX_MATCH-MIN_MATCH+1]; -/* length code for each normalized match length (0 == MIN_MATCH) */ - -local int base_length[LENGTH_CODES]; -/* First normalized length for each code (0 = MIN_MATCH) */ - -local int base_dist[D_CODES]; -/* First normalized distance for each code (0 = distance of 1) */ - -struct static_tree_desc_s { - ct_data *static_tree; /* static tree or NULL */ - intf *extra_bits; /* extra bits for each code or NULL */ - int extra_base; /* base index for extra_bits */ - int elems; /* max number of elements in the tree */ - int max_length; /* max bit length for the codes */ -}; - -local static_tree_desc static_l_desc = -{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; - -local static_tree_desc static_d_desc = -{static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; - -local static_tree_desc static_bl_desc = -{(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; - -/* =========================================================================== - * Local (static) routines in this file. - */ - -local void ct_static_init OF((void)); -local void init_block OF((deflate_state *s)); -local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); -local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); -local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); -local void build_tree OF((deflate_state *s, tree_desc *desc)); -local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); -local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); -local int build_bl_tree OF((deflate_state *s)); -local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, - int blcodes)); -local void compress_block OF((deflate_state *s, ct_data *ltree, - ct_data *dtree)); -local void set_data_type OF((deflate_state *s)); -local unsigned bi_reverse OF((unsigned value, int length)); -local void bi_windup OF((deflate_state *s)); -local void bi_flush OF((deflate_state *s)); -local void copy_block OF((deflate_state *s, charf *buf, unsigned len, - int header)); - -#ifndef DEBUG_ZLIB -# 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_ZLIB */ -# define send_code(s, c, tree) \ - { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \ - send_bits(s, tree[c].Code, tree[c].Len); } -#endif - -#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. - */ - -/* =========================================================================== - * Output a short LSB first on the stream. - * IN assertion: there is enough room in pendingBuf. - */ -#define put_short(s, w) { \ - put_byte(s, (uch)((w) & 0xff)); \ - put_byte(s, (uch)((ush)(w) >> 8)); \ -} - -/* =========================================================================== - * Send a value on a given number of bits. - * IN assertion: length <= 16 and value fits in length bits. - */ -#ifdef DEBUG_ZLIB -local void send_bits OF((deflate_state *s, int value, int length)); - -local void send_bits(s, value, length) - deflate_state *s; - int value; /* value to send */ - int length; /* number of bits */ -{ - Tracev((stderr," l %2d v %4x ", length, value)); - Assert(length > 0 && length <= 15, "invalid length"); - s->bits_sent += (ulg)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 |= (value << s->bi_valid); - put_short(s, s->bi_buf); - s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); - s->bi_valid += length - Buf_size; - } else { - s->bi_buf |= value << s->bi_valid; - s->bi_valid += length; - } -} -#else /* !DEBUG_ZLIB */ - -#define send_bits(s, value, length) \ -{ int len = length;\ - if (s->bi_valid > (int)Buf_size - len) {\ - int val = value;\ - s->bi_buf |= (val << s->bi_valid);\ - put_short(s, s->bi_buf);\ - s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ - s->bi_valid += len - Buf_size;\ - } else {\ - s->bi_buf |= (value) << s->bi_valid;\ - s->bi_valid += len;\ - }\ -} -#endif /* DEBUG_ZLIB */ - - -#define MAX(a,b) (a >= b ? a : b) -/* the arguments must not have side effects */ - -/* =========================================================================== - * Initialize the various 'constant' tables. - * To do: do this at compile time. - */ -local void ct_static_init() -{ - int n; /* iterates over tree elements */ - int bits; /* bit counter */ - int length; /* length value */ - int code; /* code value */ - int dist; /* distance index */ - ush bl_count[MAX_BITS+1]; - /* number of codes at each bit length for an optimal tree */ - - /* Initialize the mapping length (0..255) -> length code (0..28) */ - length = 0; - for (code = 0; code < LENGTH_CODES-1; code++) { - base_length[code] = length; - for (n = 0; n < (1<<extra_lbits[code]); n++) { - length_code[length++] = (uch)code; - } - } - Assert (length == 256, "ct_static_init: length != 256"); - /* Note that the length 255 (match length 258) can be represented - * in two different ways: code 284 + 5 bits or code 285, so we - * overwrite length_code[255] to use the best encoding: - */ - length_code[length-1] = (uch)code; - - /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ - dist = 0; - for (code = 0 ; code < 16; code++) { - base_dist[code] = dist; - for (n = 0; n < (1<<extra_dbits[code]); n++) { - dist_code[dist++] = (uch)code; - } - } - Assert (dist == 256, "ct_static_init: dist != 256"); - dist >>= 7; /* from now on, all distances are divided by 128 */ - for ( ; code < D_CODES; code++) { - base_dist[code] = dist << 7; - for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { - dist_code[256 + dist++] = (uch)code; - } - } - Assert (dist == 256, "ct_static_init: 256+dist != 512"); - - /* Construct the codes of the static literal tree */ - for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; - n = 0; - while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; - while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; - while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; - while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; - /* Codes 286 and 287 do not exist, but we must include them in the - * tree construction to get a canonical Huffman tree (longest code - * all ones) - */ - gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); - - /* The static distance tree is trivial: */ - for (n = 0; n < D_CODES; n++) { - static_dtree[n].Len = 5; - static_dtree[n].Code = bi_reverse(n, 5); - } -} - -/* =========================================================================== - * Initialize the tree data structures for a new zlib stream. - */ -local void ct_init(s) - deflate_state *s; -{ - if (static_dtree[0].Len == 0) { - ct_static_init(); /* To do: at compile time */ - } - - s->compressed_len = 0L; - - s->l_desc.dyn_tree = s->dyn_ltree; - s->l_desc.stat_desc = &static_l_desc; - - s->d_desc.dyn_tree = s->dyn_dtree; - s->d_desc.stat_desc = &static_d_desc; - - s->bl_desc.dyn_tree = s->bl_tree; - s->bl_desc.stat_desc = &static_bl_desc; - - s->bi_buf = 0; - s->bi_valid = 0; - s->last_eob_len = 8; /* enough lookahead for inflate */ -#ifdef DEBUG_ZLIB - s->bits_sent = 0L; -#endif - s->blocks_in_packet = 0; - - /* Initialize the first block of the first file: */ - init_block(s); -} - -/* =========================================================================== - * Initialize a new block. - */ -local void init_block(s) - deflate_state *s; -{ - int n; /* iterates over tree elements */ - - /* Initialize the trees. */ - for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; - for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; - for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; - - s->dyn_ltree[END_BLOCK].Freq = 1; - s->opt_len = s->static_len = 0L; - s->last_lit = s->matches = 0; -} - -#define SMALLEST 1 -/* Index within the heap array of least frequent node in the Huffman tree */ - - -/* =========================================================================== - * Remove the smallest element from the heap and recreate the heap with - * one less element. Updates heap and heap_len. - */ -#define pqremove(s, tree, top) \ -{\ - top = s->heap[SMALLEST]; \ - s->heap[SMALLEST] = s->heap[s->heap_len--]; \ - pqdownheap(s, tree, SMALLEST); \ -} - -/* =========================================================================== - * Compares to subtrees, using the tree depth as tie breaker when - * the subtrees have equal frequency. This minimizes the worst case length. - */ -#define smaller(tree, n, m, depth) \ - (tree[n].Freq < tree[m].Freq || \ - (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) - -/* =========================================================================== - * Restore the heap property by moving down the tree starting at node k, - * exchanging a node with the smallest of its two sons if necessary, stopping - * when the heap property is re-established (each father smaller than its - * two sons). - */ -local void pqdownheap(s, tree, k) - deflate_state *s; - ct_data *tree; /* the tree to restore */ - int k; /* node to move down */ -{ - int v = s->heap[k]; - int j = k << 1; /* left son of k */ - while (j <= s->heap_len) { - /* Set j to the smallest of the two sons: */ - if (j < s->heap_len && - smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { - j++; - } - /* Exit if v is smaller than both sons */ - if (smaller(tree, v, s->heap[j], s->depth)) break; - - /* Exchange v with the smallest son */ - s->heap[k] = s->heap[j]; k = j; - - /* And continue down the tree, setting j to the left son of k */ - j <<= 1; - } - s->heap[k] = v; -} - -/* =========================================================================== - * Compute the optimal bit lengths for a tree and update the total bit length - * for the current block. - * IN assertion: the fields freq and dad are set, heap[heap_max] and - * above are the tree nodes sorted by increasing frequency. - * OUT assertions: the field len is set to the optimal bit length, the - * array bl_count contains the frequencies for each bit length. - * The length opt_len is updated; static_len is also updated if stree is - * not null. - */ -local void gen_bitlen(s, desc) - deflate_state *s; - tree_desc *desc; /* the tree descriptor */ -{ - ct_data *tree = desc->dyn_tree; - int max_code = desc->max_code; - ct_data *stree = desc->stat_desc->static_tree; - intf *extra = desc->stat_desc->extra_bits; - int base = desc->stat_desc->extra_base; - int max_length = desc->stat_desc->max_length; - int h; /* heap index */ - int n, m; /* iterate over the tree elements */ - int bits; /* bit length */ - int xbits; /* extra bits */ - ush f; /* frequency */ - int overflow = 0; /* number of elements with bit length too large */ - - for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; - - /* In a first pass, compute the optimal bit lengths (which may - * overflow in the case of the bit length tree). - */ - tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ - - for (h = s->heap_max+1; h < HEAP_SIZE; h++) { - n = s->heap[h]; - bits = tree[tree[n].Dad].Len + 1; - if (bits > max_length) bits = max_length, overflow++; - tree[n].Len = (ush)bits; - /* We overwrite tree[n].Dad which is no longer needed */ - - if (n > max_code) continue; /* not a leaf node */ - - s->bl_count[bits]++; - xbits = 0; - if (n >= base) xbits = extra[n-base]; - f = tree[n].Freq; - s->opt_len += (ulg)f * (bits + xbits); - if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); - } - if (overflow == 0) return; - - Trace((stderr,"\nbit length overflow\n")); - /* This happens for example on obj2 and pic of the Calgary corpus */ - - /* Find the first bit length which could increase: */ - do { - bits = max_length-1; - while (s->bl_count[bits] == 0) bits--; - s->bl_count[bits]--; /* move one leaf down the tree */ - s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ - s->bl_count[max_length]--; - /* The brother of the overflow item also moves one step up, - * but this does not affect bl_count[max_length] - */ - overflow -= 2; - } while (overflow > 0); - - /* Now recompute all bit lengths, scanning in increasing frequency. - * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all - * lengths instead of fixing only the wrong ones. This idea is taken - * from 'ar' written by Haruhiko Okumura.) - */ - for (bits = max_length; bits != 0; bits--) { - n = s->bl_count[bits]; - while (n != 0) { - m = s->heap[--h]; - if (m > max_code) continue; - if (tree[m].Len != (unsigned) bits) { - Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); - s->opt_len += ((long)bits - (long)tree[m].Len) - *(long)tree[m].Freq; - tree[m].Len = (ush)bits; - } - n--; - } - } -} - -/* =========================================================================== - * Generate the codes for a given tree and bit counts (which need not be - * optimal). - * IN assertion: the array bl_count contains the bit length statistics for - * the given tree and the field len is set for all tree elements. - * OUT assertion: the field code is set for all tree elements of non - * zero code length. - */ -local void gen_codes (tree, max_code, bl_count) - ct_data *tree; /* the tree to decorate */ - int max_code; /* largest code with non zero frequency */ - ushf *bl_count; /* number of codes at each bit length */ -{ - ush next_code[MAX_BITS+1]; /* next code value for each bit length */ - ush code = 0; /* running code value */ - int bits; /* bit index */ - int n; /* code index */ - - /* The distribution counts are first used to generate the code values - * without bit reversal. - */ - for (bits = 1; bits <= MAX_BITS; bits++) { - next_code[bits] = code = (code + bl_count[bits-1]) << 1; - } - /* Check that the bit counts in bl_count are consistent. The last code - * must be all ones. - */ - Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, - "inconsistent bit counts"); - Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); - - for (n = 0; n <= max_code; n++) { - int len = tree[n].Len; - if (len == 0) continue; - /* Now reverse the bits */ - tree[n].Code = bi_reverse(next_code[len]++, len); - - Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", - n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); - } -} - -/* =========================================================================== - * Construct one Huffman tree and assigns the code bit strings and lengths. - * Update the total bit length for the current block. - * IN assertion: the field freq is set for all tree elements. - * OUT assertions: the fields len and code are set to the optimal bit length - * and corresponding code. The length opt_len is updated; static_len is - * also updated if stree is not null. The field max_code is set. - */ -local void build_tree(s, desc) - deflate_state *s; - tree_desc *desc; /* the tree descriptor */ -{ - ct_data *tree = desc->dyn_tree; - ct_data *stree = desc->stat_desc->static_tree; - int elems = desc->stat_desc->elems; - int n, m; /* iterate over heap elements */ - int max_code = -1; /* largest code with non zero frequency */ - int node; /* new node being created */ - - /* Construct the initial heap, with least frequent element in - * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. - * heap[0] is not used. - */ - s->heap_len = 0, s->heap_max = HEAP_SIZE; - - for (n = 0; n < elems; n++) { - if (tree[n].Freq != 0) { - s->heap[++(s->heap_len)] = max_code = n; - s->depth[n] = 0; - } else { - tree[n].Len = 0; - } - } - - /* The pkzip format requires that at least one distance code exists, - * and that at least one bit should be sent even if there is only one - * possible code. So to avoid special checks later on we force at least - * two codes of non zero frequency. - */ - while (s->heap_len < 2) { - node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); - tree[node].Freq = 1; - s->depth[node] = 0; - s->opt_len--; if (stree) s->static_len -= stree[node].Len; - /* node is 0 or 1 so it does not have extra bits */ - } - desc->max_code = max_code; - - /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, - * establish sub-heaps of increasing lengths: - */ - for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); - - /* Construct the Huffman tree by repeatedly combining the least two - * frequent nodes. - */ - node = elems; /* next internal node of the tree */ - do { - pqremove(s, tree, n); /* n = node of least frequency */ - m = s->heap[SMALLEST]; /* m = node of next least frequency */ - - s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ - s->heap[--(s->heap_max)] = m; - - /* Create a new node father of n and m */ - tree[node].Freq = tree[n].Freq + tree[m].Freq; - s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); - tree[n].Dad = tree[m].Dad = (ush)node; -#ifdef DUMP_BL_TREE - if (tree == s->bl_tree) { - fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", - node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); - } -#endif - /* and insert the new node in the heap */ - s->heap[SMALLEST] = node++; - pqdownheap(s, tree, SMALLEST); - - } while (s->heap_len >= 2); - - s->heap[--(s->heap_max)] = s->heap[SMALLEST]; - - /* At this point, the fields freq and dad are set. We can now - * generate the bit lengths. - */ - gen_bitlen(s, (tree_desc *)desc); - - /* The field len is now set, we can generate the bit codes */ - gen_codes ((ct_data *)tree, max_code, s->bl_count); -} - -/* =========================================================================== - * Scan a literal or distance tree to determine the frequencies of the codes - * in the bit length tree. - */ -local void scan_tree (s, tree, max_code) - deflate_state *s; - ct_data *tree; /* the tree to be scanned */ - int max_code; /* and its largest code of non zero frequency */ -{ - int n; /* iterates over all tree elements */ - int prevlen = -1; /* last emitted length */ - int curlen; /* length of current code */ - int nextlen = tree[0].Len; /* length of next code */ - int count = 0; /* repeat count of the current code */ - int max_count = 7; /* max repeat count */ - int min_count = 4; /* min repeat count */ - - if (nextlen == 0) max_count = 138, min_count = 3; - tree[max_code+1].Len = (ush)0xffff; /* guard */ - - for (n = 0; n <= max_code; n++) { - curlen = nextlen; nextlen = tree[n+1].Len; - if (++count < max_count && curlen == nextlen) { - continue; - } else if (count < min_count) { - s->bl_tree[curlen].Freq += count; - } else if (curlen != 0) { - if (curlen != prevlen) s->bl_tree[curlen].Freq++; - s->bl_tree[REP_3_6].Freq++; - } else if (count <= 10) { - s->bl_tree[REPZ_3_10].Freq++; - } else { - s->bl_tree[REPZ_11_138].Freq++; - } - count = 0; prevlen = curlen; - if (nextlen == 0) { - max_count = 138, min_count = 3; - } else if (curlen == nextlen) { - max_count = 6, min_count = 3; - } else { - max_count = 7, min_count = 4; - } - } -} - -/* =========================================================================== - * Send a literal or distance tree in compressed form, using the codes in - * bl_tree. - */ -local void send_tree (s, tree, max_code) - deflate_state *s; - ct_data *tree; /* the tree to be scanned */ - int max_code; /* and its largest code of non zero frequency */ -{ - int n; /* iterates over all tree elements */ - int prevlen = -1; /* last emitted length */ - int curlen; /* length of current code */ - int nextlen = tree[0].Len; /* length of next code */ - int count = 0; /* repeat count of the current code */ - int max_count = 7; /* max repeat count */ - int min_count = 4; /* min repeat count */ - - /* tree[max_code+1].Len = -1; */ /* guard already set */ - if (nextlen == 0) max_count = 138, min_count = 3; - - for (n = 0; n <= max_code; n++) { - curlen = nextlen; nextlen = tree[n+1].Len; - if (++count < max_count && curlen == nextlen) { - continue; - } else if (count < min_count) { - do { send_code(s, curlen, s->bl_tree); } while (--count != 0); - - } else if (curlen != 0) { - if (curlen != prevlen) { - send_code(s, curlen, s->bl_tree); count--; - } - Assert(count >= 3 && count <= 6, " 3_6?"); - send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); - - } else if (count <= 10) { - send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); - - } else { - send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); - } - count = 0; prevlen = curlen; - if (nextlen == 0) { - max_count = 138, min_count = 3; - } else if (curlen == nextlen) { - max_count = 6, min_count = 3; - } else { - max_count = 7, min_count = 4; - } - } -} - -/* =========================================================================== - * Construct the Huffman tree for the bit lengths and return the index in - * bl_order of the last bit length code to send. - */ -local int build_bl_tree(s) - deflate_state *s; -{ - int max_blindex; /* index of last bit length code of non zero freq */ - - /* Determine the bit length frequencies for literal and distance trees */ - scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); - scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); - - /* Build the bit length tree: */ - build_tree(s, (tree_desc *)(&(s->bl_desc))); - /* opt_len now includes the length of the tree representations, except - * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. - */ - - /* Determine the number of bit length codes to send. The pkzip format - * requires that at least 4 bit length codes be sent. (appnote.txt says - * 3 but the actual value used is 4.) - */ - for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { - if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; - } - /* Update opt_len to include the bit length tree and counts */ - s->opt_len += 3*(max_blindex+1) + 5+5+4; - Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", - s->opt_len, s->static_len)); - - return max_blindex; -} - -/* =========================================================================== - * Send the header for a block using dynamic Huffman trees: the counts, the - * lengths of the bit length codes, the literal tree and the distance tree. - * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. - */ -local void send_all_trees(s, lcodes, dcodes, blcodes) - deflate_state *s; - int lcodes, dcodes, blcodes; /* number of codes for each tree */ -{ - int rank; /* index in bl_order */ - - Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); - Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, - "too many codes"); - Tracev((stderr, "\nbl counts: ")); - send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ - send_bits(s, dcodes-1, 5); - send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ - for (rank = 0; rank < blcodes; rank++) { - Tracev((stderr, "\nbl code %2d ", bl_order[rank])); - send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); - } - Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); - - send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ - Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); - - send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ - Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); -} - -/* =========================================================================== - * Send a stored block - */ -local void ct_stored_block(s, buf, stored_len, eof) - deflate_state *s; - charf *buf; /* input block */ - ulg stored_len; /* length of input block */ - int eof; /* true if this is the last block for a file */ -{ - send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ - s->compressed_len = (s->compressed_len + 3 + 7) & ~7L; - s->compressed_len += (stored_len + 4) << 3; - - copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ -} - -/* Send just the `stored block' type code without any length bytes or data. - */ -local void ct_stored_type_only(s) - deflate_state *s; -{ - send_bits(s, (STORED_BLOCK << 1), 3); - bi_windup(s); - s->compressed_len = (s->compressed_len + 3) & ~7L; -} - - -/* =========================================================================== - * Send one empty static block to give enough lookahead for inflate. - * This takes 10 bits, of which 7 may remain in the bit buffer. - * The current inflate code requires 9 bits of lookahead. If the EOB - * code for the previous block was coded on 5 bits or less, inflate - * may have only 5+3 bits of lookahead to decode this EOB. - * (There are no problems if the previous block is stored or fixed.) - */ -local void ct_align(s) - deflate_state *s; -{ - send_bits(s, STATIC_TREES<<1, 3); - send_code(s, END_BLOCK, static_ltree); - s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ - bi_flush(s); - /* Of the 10 bits for the empty block, we have already sent - * (10 - bi_valid) bits. The lookahead for the EOB of the previous - * block was thus its length plus what we have just sent. - */ - if (s->last_eob_len + 10 - s->bi_valid < 9) { - send_bits(s, STATIC_TREES<<1, 3); - send_code(s, END_BLOCK, static_ltree); - s->compressed_len += 10L; - bi_flush(s); - } - s->last_eob_len = 7; -} - -/* =========================================================================== - * Determine the best encoding for the current block: dynamic trees, static - * trees or store, and output the encoded block to the zip file. This function - * returns the total compressed length for the file so far. - */ -local ulg ct_flush_block(s, buf, stored_len, flush) - deflate_state *s; - charf *buf; /* input block, or NULL if too old */ - ulg stored_len; /* length of input block */ - int flush; /* Z_FINISH if this is the last block for a file */ -{ - ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ - int max_blindex; /* index of last bit length code of non zero freq */ - int eof = flush == Z_FINISH; - - ++s->blocks_in_packet; - - /* Check if the file is ascii or binary */ - if (s->data_type == UNKNOWN) set_data_type(s); - - /* Construct the literal and distance trees */ - build_tree(s, (tree_desc *)(&(s->l_desc))); - Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, - s->static_len)); - - build_tree(s, (tree_desc *)(&(s->d_desc))); - Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, - s->static_len)); - /* At this point, opt_len and static_len are the total bit lengths of - * the compressed block data, excluding the tree representations. - */ - - /* Build the bit length tree for the above two trees, and get the index - * in bl_order of the last bit length code to send. - */ - max_blindex = build_bl_tree(s); - - /* Determine the best encoding. Compute first the block length in bytes */ - opt_lenb = (s->opt_len+3+7)>>3; - static_lenb = (s->static_len+3+7)>>3; - - Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", - opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, - s->last_lit)); - - if (static_lenb <= opt_lenb) opt_lenb = static_lenb; - - /* If compression failed and this is the first and last block, - * and if the .zip file can be seeked (to rewrite the local header), - * the whole file is transformed into a stored file: - */ -#ifdef STORED_FILE_OK -# ifdef FORCE_STORED_FILE - if (eof && compressed_len == 0L) /* force stored file */ -# else - if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) -# endif - { - /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ - if (buf == (charf*)0) error ("block vanished"); - - copy_block(buf, (unsigned)stored_len, 0); /* without header */ - s->compressed_len = stored_len << 3; - s->method = STORED; - } else -#endif /* STORED_FILE_OK */ - - /* For Z_PACKET_FLUSH, if we don't achieve the required minimum - * compression, and this block contains all the data since the last - * time we used Z_PACKET_FLUSH, then just omit this block completely - * from the output. - */ - if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1 - && opt_lenb > stored_len - s->minCompr) { - s->blocks_in_packet = 0; - /* output nothing */ - } else - -#ifdef FORCE_STORED - if (buf != (char*)0) /* force stored block */ -#else - if (stored_len+4 <= opt_lenb && buf != (char*)0) - /* 4: two words for the lengths */ -#endif - { - /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. - * Otherwise we can't have processed more than WSIZE input bytes since - * the last block flush, because compression would have been - * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to - * transform a block into a stored block. - */ - ct_stored_block(s, buf, stored_len, eof); - } else - -#ifdef FORCE_STATIC - if (static_lenb >= 0) /* force static trees */ -#else - if (static_lenb == opt_lenb) -#endif - { - send_bits(s, (STATIC_TREES<<1)+eof, 3); - compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); - s->compressed_len += 3 + s->static_len; - } else { - send_bits(s, (DYN_TREES<<1)+eof, 3); - send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, - max_blindex+1); - compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); - s->compressed_len += 3 + s->opt_len; - } - Assert (s->compressed_len == s->bits_sent, "bad compressed size"); - init_block(s); - - if (eof) { - bi_windup(s); - s->compressed_len += 7; /* align on byte boundary */ - } - Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, - s->compressed_len-7*eof)); - - return s->compressed_len >> 3; -} - -/* =========================================================================== - * Save the match info and tally the frequency counts. Return true if - * the current block must be flushed. - */ -local int ct_tally (s, dist, lc) - deflate_state *s; - int dist; /* distance of matched string */ - int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ -{ - s->d_buf[s->last_lit] = (ush)dist; - s->l_buf[s->last_lit++] = (uch)lc; - if (dist == 0) { - /* lc is the unmatched char */ - s->dyn_ltree[lc].Freq++; - } else { - s->matches++; - /* Here, lc is the match length - MIN_MATCH */ - dist--; /* dist = match distance - 1 */ - Assert((ush)dist < (ush)MAX_DIST(s) && - (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && - (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match"); - - s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; - s->dyn_dtree[d_code(dist)].Freq++; - } - - /* Try to guess if it is profitable to stop the current block here */ - if (s->level > 2 && (s->last_lit & 0xfff) == 0) { - /* Compute an upper bound for the compressed length */ - ulg out_length = (ulg)s->last_lit*8L; - ulg in_length = (ulg)s->strstart - s->block_start; - int dcode; - for (dcode = 0; dcode < D_CODES; dcode++) { - out_length += (ulg)s->dyn_dtree[dcode].Freq * - (5L+extra_dbits[dcode]); - } - out_length >>= 3; - Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", - s->last_lit, in_length, out_length, - 100L - out_length*100L/in_length)); - if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; - } - return (s->last_lit == s->lit_bufsize-1); - /* We avoid equality with lit_bufsize because of wraparound at 64K - * on 16 bit machines and because stored blocks are restricted to - * 64K-1 bytes. - */ -} - -/* =========================================================================== - * Send the block data compressed using the given Huffman trees - */ -local void compress_block(s, ltree, dtree) - deflate_state *s; - ct_data *ltree; /* literal tree */ - ct_data *dtree; /* distance tree */ -{ - unsigned dist; /* distance of matched string */ - int lc; /* match length or unmatched char (if dist == 0) */ - unsigned lx = 0; /* running index in l_buf */ - unsigned code; /* the code to send */ - int extra; /* number of extra bits to send */ - - if (s->last_lit != 0) do { - dist = s->d_buf[lx]; - lc = s->l_buf[lx++]; - if (dist == 0) { - send_code(s, lc, ltree); /* send a literal byte */ - Tracecv(isgraph(lc), (stderr," '%c' ", lc)); - } else { - /* Here, lc is the match length - MIN_MATCH */ - code = length_code[lc]; - send_code(s, code+LITERALS+1, ltree); /* send the length code */ - extra = extra_lbits[code]; - if (extra != 0) { - lc -= base_length[code]; - send_bits(s, lc, extra); /* send the extra length bits */ - } - dist--; /* dist is now the match distance - 1 */ - code = d_code(dist); - Assert (code < D_CODES, "bad d_code"); - - send_code(s, code, dtree); /* send the distance code */ - extra = extra_dbits[code]; - if (extra != 0) { - dist -= base_dist[code]; - send_bits(s, dist, extra); /* send the extra distance bits */ - } - } /* literal or match pair ? */ - - /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ - Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); - - } while (lx < s->last_lit); - - send_code(s, END_BLOCK, ltree); - s->last_eob_len = ltree[END_BLOCK].Len; -} - -/* =========================================================================== - * Set the data type to ASCII or BINARY, using a crude approximation: - * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. - * IN assertion: the fields freq of dyn_ltree are set and the total of all - * frequencies does not exceed 64K (to fit in an int on 16 bit machines). - */ -local void set_data_type(s) - deflate_state *s; -{ - int n = 0; - unsigned ascii_freq = 0; - unsigned bin_freq = 0; - while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; - while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; - while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; - s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII); -} - -/* =========================================================================== - * Reverse the first len bits of a code, using straightforward code (a faster - * method would use a table) - * IN assertion: 1 <= len <= 15 - */ -local unsigned bi_reverse(code, len) - unsigned code; /* the value to invert */ - int len; /* its bit length */ -{ - register unsigned res = 0; - do { - res |= code & 1; - code >>= 1, res <<= 1; - } while (--len > 0); - return res >> 1; -} - -/* =========================================================================== - * Flush the bit buffer, keeping at most 7 bits in it. - */ -local void bi_flush(s) - deflate_state *s; -{ - if (s->bi_valid == 16) { - put_short(s, s->bi_buf); - s->bi_buf = 0; - s->bi_valid = 0; - } else if (s->bi_valid >= 8) { - put_byte(s, (Byte)s->bi_buf); - s->bi_buf >>= 8; - s->bi_valid -= 8; - } -} - -/* =========================================================================== - * Flush the bit buffer and align the output on a byte boundary - */ -local void bi_windup(s) - deflate_state *s; -{ - if (s->bi_valid > 8) { - put_short(s, s->bi_buf); - } else if (s->bi_valid > 0) { - put_byte(s, (Byte)s->bi_buf); - } - s->bi_buf = 0; - s->bi_valid = 0; -#ifdef DEBUG_ZLIB - s->bits_sent = (s->bits_sent+7) & ~7; -#endif -} - -/* =========================================================================== - * Copy a stored block, storing first the length and its - * one's complement if requested. - */ -local void copy_block(s, buf, len, header) - deflate_state *s; - charf *buf; /* the input data */ - unsigned len; /* its length */ - int header; /* true if block header must be written */ -{ - bi_windup(s); /* align on byte boundary */ - s->last_eob_len = 8; /* enough lookahead for inflate */ - - if (header) { - put_short(s, (ush)len); - put_short(s, (ush)~len); -#ifdef DEBUG_ZLIB - s->bits_sent += 2*16; -#endif - } -#ifdef DEBUG_ZLIB - s->bits_sent += (ulg)len<<3; -#endif - while (len--) { - put_byte(s, *buf++); - } -} - - /*+++++*/ /* infblock.h -- header to use infblock.c * Copyright (C) 1995 Mark Adler |