(*((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
projects / ppp.git / commitdiff