diff options
Diffstat (limited to 'lib/zlib/include/deflate.h')
| -rw-r--r-- | lib/zlib/include/deflate.h | 636 |
1 files changed, 318 insertions, 318 deletions
diff --git a/lib/zlib/include/deflate.h b/lib/zlib/include/deflate.h index d39189a..0630d9f 100644 --- a/lib/zlib/include/deflate.h +++ b/lib/zlib/include/deflate.h @@ -1,318 +1,318 @@ -/* deflate.h -- internal compression state - * Copyright (C) 1995-2002 Jean-loup Gailly - * For conditions of distribution and use, see copyright notice in zlib.h - */ - -/* WARNING: this file should *not* be used by applications. It is - part of the implementation of the compression library and is - subject to change. Applications should only use zlib.h. - */ - -/* @(#) $Id: deflate.h,v 1.1 2003-09-14 18:16:26 pixel Exp $ */ - -#ifndef _DEFLATE_H -#define _DEFLATE_H - -#include "zutil.h" - -/* =========================================================================== - * Internal compression state. - */ - -#define LENGTH_CODES 29 -/* number of length codes, not counting the special END_BLOCK code */ - -#define LITERALS 256 -/* number of literal bytes 0..255 */ - -#define L_CODES (LITERALS+1+LENGTH_CODES) -/* number of Literal or Length codes, including the END_BLOCK code */ - -#define D_CODES 30 -/* number of distance codes */ - -#define BL_CODES 19 -/* number of codes used to transfer the bit lengths */ - -#define HEAP_SIZE (2*L_CODES+1) -/* maximum heap size */ - -#define MAX_BITS 15 -/* All codes must not exceed MAX_BITS bits */ - -#define INIT_STATE 42 -#define BUSY_STATE 113 -#define FINISH_STATE 666 -/* Stream status */ - - -/* Data structure describing a single value and its code string. */ -typedef struct ct_data_s { - union { - 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 internal_state { - z_streamp strm; /* pointer back to this zlib stream */ - int status; /* as the name implies */ - Bytef *pending_buf; /* output still pending */ - ulg pending_buf_size; /* size of pending_buf */ - Bytef *pending_out; /* next pending byte to output to the stream */ - int pending; /* nb of bytes in the pending buffer */ - int noheader; /* suppress zlib header and adler32 */ - Byte data_type; /* UNKNOWN, BINARY or ASCII */ - Byte method; /* STORED (for zip only) or DEFLATED */ - int last_flush; /* value of flush param for previous deflate call */ - - /* 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 */ - uInt matches; /* number of string matches in current block */ - int last_eob_len; /* bit length of EOB code for last block */ - -#ifdef DEBUG - ulg compressed_len; /* total bit length of compressed file mod 2^32 */ - ulg bits_sent; /* bit length of compressed data sent mod 2^32 */ -#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. - */ - -} 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 */ -void _tr_init OF((deflate_state *s)); -int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); -void _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, - int eof)); -void _tr_align OF((deflate_state *s)); -void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, - int eof)); - -#define d_code(dist) \ - ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)]) -/* Mapping from a distance to a distance code. dist is the distance - 1 and - * must not have side effects. _dist_code[256] and _dist_code[257] are never - * used. - */ - -#ifndef DEBUG -/* Inline versions of _tr_tally for speed: */ - -#if defined(GEN_TREES_H) || !defined(STDC) - extern uch _length_code[]; - extern uch _dist_code[]; -#else - extern const uch _length_code[]; - extern const uch _dist_code[]; -#endif - -# define _tr_tally_lit(s, c, flush) \ - { uch cc = (c); \ - s->d_buf[s->last_lit] = 0; \ - s->l_buf[s->last_lit++] = cc; \ - s->dyn_ltree[cc].Freq++; \ - flush = (s->last_lit == s->lit_bufsize-1); \ - } -# define _tr_tally_dist(s, distance, length, flush) \ - { uch len = (length); \ - ush dist = (distance); \ - s->d_buf[s->last_lit] = dist; \ - s->l_buf[s->last_lit++] = len; \ - dist--; \ - s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \ - s->dyn_dtree[d_code(dist)].Freq++; \ - flush = (s->last_lit == s->lit_bufsize-1); \ - } -#else -# define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c) -# define _tr_tally_dist(s, distance, length, flush) \ - flush = _tr_tally(s, distance, length) -#endif - -#endif +/* deflate.h -- internal compression state
+ * Copyright (C) 1995-2002 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+ part of the implementation of the compression library and is
+ subject to change. Applications should only use zlib.h.
+ */
+
+/* @(#) $Id: deflate.h,v 1.2 2004-11-27 21:43:51 pixel Exp $ */
+
+#ifndef _DEFLATE_H
+#define _DEFLATE_H
+
+#include "zutil.h"
+
+/* ===========================================================================
+ * Internal compression state.
+ */
+
+#define LENGTH_CODES 29
+/* number of length codes, not counting the special END_BLOCK code */
+
+#define LITERALS 256
+/* number of literal bytes 0..255 */
+
+#define L_CODES (LITERALS+1+LENGTH_CODES)
+/* number of Literal or Length codes, including the END_BLOCK code */
+
+#define D_CODES 30
+/* number of distance codes */
+
+#define BL_CODES 19
+/* number of codes used to transfer the bit lengths */
+
+#define HEAP_SIZE (2*L_CODES+1)
+/* maximum heap size */
+
+#define MAX_BITS 15
+/* All codes must not exceed MAX_BITS bits */
+
+#define INIT_STATE 42
+#define BUSY_STATE 113
+#define FINISH_STATE 666
+/* Stream status */
+
+
+/* Data structure describing a single value and its code string. */
+typedef struct ct_data_s {
+ union {
+ 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 internal_state {
+ z_streamp strm; /* pointer back to this zlib stream */
+ int status; /* as the name implies */
+ Bytef *pending_buf; /* output still pending */
+ ulg pending_buf_size; /* size of pending_buf */
+ Bytef *pending_out; /* next pending byte to output to the stream */
+ int pending; /* nb of bytes in the pending buffer */
+ int noheader; /* suppress zlib header and adler32 */
+ Byte data_type; /* UNKNOWN, BINARY or ASCII */
+ Byte method; /* STORED (for zip only) or DEFLATED */
+ int last_flush; /* value of flush param for previous deflate call */
+
+ /* 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 */
+ uInt matches; /* number of string matches in current block */
+ int last_eob_len; /* bit length of EOB code for last block */
+
+#ifdef DEBUG
+ ulg compressed_len; /* total bit length of compressed file mod 2^32 */
+ ulg bits_sent; /* bit length of compressed data sent mod 2^32 */
+#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.
+ */
+
+} 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 */
+void _tr_init OF((deflate_state *s));
+int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
+void _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
+ int eof));
+void _tr_align OF((deflate_state *s));
+void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
+ int eof));
+
+#define d_code(dist) \
+ ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
+/* Mapping from a distance to a distance code. dist is the distance - 1 and
+ * must not have side effects. _dist_code[256] and _dist_code[257] are never
+ * used.
+ */
+
+#ifndef DEBUG
+/* Inline versions of _tr_tally for speed: */
+
+#if defined(GEN_TREES_H) || !defined(STDC)
+ extern uch _length_code[];
+ extern uch _dist_code[];
+#else
+ extern const uch _length_code[];
+ extern const uch _dist_code[];
+#endif
+
+# define _tr_tally_lit(s, c, flush) \
+ { uch cc = (c); \
+ s->d_buf[s->last_lit] = 0; \
+ s->l_buf[s->last_lit++] = cc; \
+ s->dyn_ltree[cc].Freq++; \
+ flush = (s->last_lit == s->lit_bufsize-1); \
+ }
+# define _tr_tally_dist(s, distance, length, flush) \
+ { uch len = (length); \
+ ush dist = (distance); \
+ s->d_buf[s->last_lit] = dist; \
+ s->l_buf[s->last_lit++] = len; \
+ dist--; \
+ s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
+ s->dyn_dtree[d_code(dist)].Freq++; \
+ flush = (s->last_lit == s->lit_bufsize-1); \
+ }
+#else
+# define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
+# define _tr_tally_dist(s, distance, length, flush) \
+ flush = _tr_tally(s, distance, length)
+#endif
+
+#endif
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