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| author | Paul Mackerras <paulus@ozlabs.org> | 2023-03-18 17:32:20 +1100 |
|---|---|---|
| committer | Paul Mackerras <paulus@ozlabs.org> | 2023-03-18 17:32:20 +1100 |
| commit | 3b0fe68ef1e28bd0db095a1a7c9bdcbe83a58588 (patch) | |
| tree | befc4134da51ab757d8d08a3132829ce81624b1d | |
| parent | 1fe83840992fc139eda4cc51899be5224c246ddd (diff) | |
| download | ppp-3b0fe68ef1e28bd0db095a1a7c9bdcbe83a58588.tar.gz | |
pppdump: Remove compression functions from local copy of zlib
They aren't used (pppdump only needs decompression), and removing the
unused code avoids getting reports from automated tools about possible
errors in the unused code.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
| -rw-r--r-- | pppdump/zlib.c | 2465 | ||||
| -rw-r--r-- | pppdump/zlib.h | 220 |
2 files changed, 1 insertions, 2684 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 diff --git a/pppdump/zlib.h b/pppdump/zlib.h index 082f649..4bdb164 100644 --- a/pppdump/zlib.h +++ b/pppdump/zlib.h @@ -69,15 +69,6 @@ # include <unix.h> #endif -/* Maximum value for memLevel in deflateInit2 */ -#ifndef MAX_MEM_LEVEL -# ifdef MAXSEG_64K -# define MAX_MEM_LEVEL 8 -# else -# define MAX_MEM_LEVEL 9 -# endif -#endif - #ifndef FAR # define FAR #endif @@ -87,14 +78,7 @@ # define MAX_WBITS 15 /* 32K LZ77 window */ #endif -/* The memory requirements for deflate are (in bytes): - 1 << (windowBits+2) + 1 << (memLevel+9) - that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values) - plus a few kilobytes for small objects. For example, if you want to reduce - the default memory requirements from 256K to 128K, compile with - make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7" - Of course this will generally degrade compression (there's no free lunch). - +/* The memory requirements for inflate are (in bytes) 1 << windowBits that is, 32K for windowBits=15 (default value) plus a few kilobytes for small objects. @@ -248,114 +232,6 @@ extern char *zlib_version; /* basic functions */ -extern int deflateInit OF((z_stream *strm, int level)); -/* - Initializes the internal stream state for compression. The fields - zalloc, zfree and opaque must be initialized before by the caller. - If zalloc and zfree are set to Z_NULL, deflateInit updates them to - use default allocation functions. - - The compression level must be Z_DEFAULT_COMPRESSION, or between 1 and 9: - 1 gives best speed, 9 gives best compression. Z_DEFAULT_COMPRESSION requests - a default compromise between speed and compression (currently equivalent - to level 6). - - deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not - enough memory, Z_STREAM_ERROR if level is not a valid compression level. - msg is set to null if there is no error message. deflateInit does not - perform any compression: this will be done by deflate(). -*/ - - -extern int deflate OF((z_stream *strm, int flush)); -/* - Performs one or both of the following actions: - - - Compress more input starting at next_in and update next_in and avail_in - accordingly. If not all input can be processed (because there is not - enough room in the output buffer), next_in and avail_in are updated and - processing will resume at this point for the next call of deflate(). - - - Provide more output starting at next_out and update next_out and avail_out - accordingly. This action is forced if the parameter flush is non zero. - Forcing flush frequently degrades the compression ratio, so this parameter - should be set only when necessary (in interactive applications). - Some output may be provided even if flush is not set. - - Before the call of deflate(), the application should ensure that at least - one of the actions is possible, by providing more input and/or consuming - more output, and updating avail_in or avail_out accordingly; avail_out - should never be zero before the call. The application can consume the - compressed output when it wants, for example when the output buffer is full - (avail_out == 0), or after each call of deflate(). - - If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression - block is terminated and flushed to the output buffer so that the - decompressor can get all input data available so far. For method 9, a future - variant on method 8, the current block will be flushed but not terminated. - If flush is set to Z_FULL_FLUSH, the compression block is terminated, a - special marker is output and the compression dictionary is discarded; this - is useful to allow the decompressor to synchronize if one compressed block - has been damaged (see inflateSync below). Flushing degrades compression and - so should be used only when necessary. Using Z_FULL_FLUSH too often can - seriously degrade the compression. If deflate returns with avail_out == 0, - this function must be called again with the same value of the flush - parameter and more output space (updated avail_out), until the flush is - complete (deflate returns with non-zero avail_out). - - If the parameter flush is set to Z_PACKET_FLUSH, the compression - block is terminated, and a zero-length stored block is output, - omitting the length bytes (the effect of this is that the 3-bit type - code 000 for a stored block is output, and the output is then - byte-aligned). This is designed for use at the end of a PPP packet. - In addition, if the current compression block contains all the data - since the last Z_PACKET_FLUSH, it is never output as a stored block. - If the current compression block output as a static or dynamic block - would not be at least `minCompression' bytes smaller than the - original data, then nothing is output for that block. (The type - code for the zero-length stored block is still output, resulting in - a single zero byte being output for the whole packet.) - `MinCompression' is a parameter to deflateInit2, or 0 if deflateInit - is used. - - If the parameter flush is set to Z_FINISH, all pending input is processed, - all pending output is flushed and deflate returns with Z_STREAM_END if there - was enough output space; if deflate returns with Z_OK, this function must be - called again with Z_FINISH and more output space (updated avail_out) but no - more input data, until it returns with Z_STREAM_END or an error. After - deflate has returned Z_STREAM_END, the only possible operations on the - stream are deflateReset or deflateEnd. - - Z_FINISH can be used immediately after deflateInit if all the compression - is to be done in a single step. In this case, avail_out must be at least - 0.1% larger than avail_in plus 12 bytes. If deflate does not return - Z_STREAM_END, then it must be called again as described above. - - deflate() may update data_type if it can make a good guess about - the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered - binary. This field is only for information purposes and does not affect - the compression algorithm in any manner. - - deflate() returns Z_OK if some progress has been made (more input - processed or more output produced), Z_STREAM_END if all input has been - consumed and all output has been produced (only when flush is set to - Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example - if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible. -*/ - - -extern int deflateEnd OF((z_stream *strm)); -/* - All dynamically allocated data structures for this stream are freed. - This function discards any unprocessed input and does not flush any - pending output. - - deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the - stream state was inconsistent. In the error case, msg may be set - but then points to a static string (which must not be deallocated). -*/ - - extern int inflateInit OF((z_stream *strm)); /* Initializes the internal stream state for decompression. The fields @@ -438,100 +314,6 @@ extern int inflateEnd OF((z_stream *strm)); The following functions are needed only in some special applications. */ -extern int deflateInit2 OF((z_stream *strm, - int level, - int method, - int windowBits, - int memLevel, - int strategy, - int minCompression)); -/* - This is another version of deflateInit with more compression options. The - fields next_in, zalloc and zfree must be initialized before by the caller. - - The method parameter is the compression method. It must be 8 in this - version of the library. (Method 9 will allow a 64K history buffer and - partial block flushes.) - - The windowBits parameter is the base two logarithm of the window size - (the size of the history buffer). It should be in the range 8..15 for this - version of the library (the value 16 will be allowed for method 9). Larger - values of this parameter result in better compression at the expense of - memory usage. The default value is 15 if deflateInit is used instead. - - The memLevel parameter specifies how much memory should be allocated - for the internal compression state. memLevel=1 uses minimum memory but - is slow and reduces compression ratio; memLevel=9 uses maximum memory - for optimal speed. The default value is 8. See zconf.h for total memory - usage as a function of windowBits and memLevel. - - The strategy parameter is used to tune the compression algorithm. Use - the value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data - produced by a filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman - encoding only (no string match). Filtered data consists mostly of small - values with a somewhat random distribution. In this case, the - compression algorithm is tuned to compress them better. The strategy - parameter only affects the compression ratio but not the correctness of - the compressed output even if it is not set appropriately. - - The minCompression parameter specifies the minimum reduction in size - required for a compressed block to be output when Z_PACKET_FLUSH is - used (see the description of deflate above). - - If next_in is not null, the library will use this buffer to hold also - some history information; the buffer must either hold the entire input - data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in - is null, the library will allocate its own history buffer (and leave next_in - null). next_out need not be provided here but must be provided by the - application for the next call of deflate(). - - If the history buffer is provided by the application, next_in must - must never be changed by the application since the compressor maintains - information inside this buffer from call to call; the application - must provide more input only by increasing avail_in. next_in is always - reset by the library in this case. - - deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was - not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as - an invalid method). msg is set to null if there is no error message. - deflateInit2 does not perform any compression: this will be done by - deflate(). -*/ - -extern int deflateCopy OF((z_stream *dest, - z_stream *source)); -/* - Sets the destination stream as a complete copy of the source stream. If - the source stream is using an application-supplied history buffer, a new - buffer is allocated for the destination stream. The compressed output - buffer is always application-supplied. It's the responsibility of the - application to provide the correct values of next_out and avail_out for the - next call of deflate. - - This function is useful when several compression strategies will be - tried, for example when there are several ways of pre-processing the input - data with a filter. The streams that will be discarded should then be freed - by calling deflateEnd. Note that deflateCopy duplicates the internal - compression state which can be quite large, so this strategy is slow and - can consume lots of memory. - - deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not - enough memory, Z_STREAM_ERROR if the source stream state was inconsistent - (such as zalloc being NULL). msg is left unchanged in both source and - destination. -*/ - -extern int deflateReset OF((z_stream *strm)); -/* - This function is equivalent to deflateEnd followed by deflateInit, - but does not free and reallocate all the internal compression state. - The stream will keep the same compression level and any other attributes - that may have been set by deflateInit2. - - deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent (such as zalloc or state being NULL). -*/ - extern int inflateInit2 OF((z_stream *strm, int windowBits)); /* |