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Sweden-Number/dlls/cabinet/deflate.c

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/* deflate.c -- compress data using the deflation algorithm
*
* Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*
* Jean-loup Gailly Mark Adler
* jloup@gzip.org madler@alumni.caltech.edu
*/
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "zlib.h"
#define DEF_MEM_LEVEL 8
#define DEF_WBITS MAX_WBITS
#define zmemcpy memcpy
#define zmemzero(dest, len) memset(dest, 0, len)
#define Assert(cond,msg)
#define Trace(x)
#define Tracev(x)
#define Tracevv(x)
#define Tracecv(c,x)
#define ZALLOC(strm, items, size) \
(*((strm)->zalloc))((strm)->opaque, (items), (size))
#define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
#define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
/* Reverse the bytes in a 32-bit value */
#define ZSWAP32(q) ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
(((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
static const char * const z_errmsg[10] = {
(z_const char *)"need dictionary", /* Z_NEED_DICT 2 */
(z_const char *)"stream end", /* Z_STREAM_END 1 */
(z_const char *)"", /* Z_OK 0 */
(z_const char *)"file error", /* Z_ERRNO (-1) */
(z_const char *)"stream error", /* Z_STREAM_ERROR (-2) */
(z_const char *)"data error", /* Z_DATA_ERROR (-3) */
(z_const char *)"insufficient memory", /* Z_MEM_ERROR (-4) */
(z_const char *)"buffer error", /* Z_BUF_ERROR (-5) */
(z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
(z_const char *)""
};
#define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
#define ERR_RETURN(strm,err) \
return (strm->msg = ERR_MSG(err), (err))
/* To be used only when the state is known to be valid */
#define STORED_BLOCK 0
#define STATIC_TREES 1
#define DYN_TREES 2
/* The three kinds of block type */
#define MIN_MATCH 3
#define MAX_MATCH 258
/* The minimum and maximum match lengths */
#define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
#define BASE 65521U /* largest prime smaller than 65536 */
#define NMAX 5552
/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
#define DO1(buf,i) {adler += (buf)[i]; sum2 += adler;}
#define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
#define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
#define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
#define DO16(buf) DO8(buf,0); DO8(buf,8);
#define MOD(a) a %= BASE
#define MOD28(a) a %= BASE
#define MOD63(a) a %= BASE
static uLong adler32( uLong adler, const Bytef *buf, uInt len )
{
unsigned long sum2;
unsigned n;
/* split Adler-32 into component sums */
sum2 = (adler >> 16) & 0xffff;
adler &= 0xffff;
/* in case user likes doing a byte at a time, keep it fast */
if (len == 1) {
adler += buf[0];
if (adler >= BASE)
adler -= BASE;
sum2 += adler;
if (sum2 >= BASE)
sum2 -= BASE;
return adler | (sum2 << 16);
}
/* initial Adler-32 value (deferred check for len == 1 speed) */
if (buf == Z_NULL)
return 1L;
/* in case short lengths are provided, keep it somewhat fast */
if (len < 16) {
while (len--) {
adler += *buf++;
sum2 += adler;
}
if (adler >= BASE)
adler -= BASE;
MOD28(sum2); /* only added so many BASE's */
return adler | (sum2 << 16);
}
/* do length NMAX blocks -- requires just one modulo operation */
while (len >= NMAX) {
len -= NMAX;
n = NMAX / 16; /* NMAX is divisible by 16 */
do {
DO16(buf); /* 16 sums unrolled */
buf += 16;
} while (--n);
MOD(adler);
MOD(sum2);
}
/* do remaining bytes (less than NMAX, still just one modulo) */
if (len) { /* avoid modulos if none remaining */
while (len >= 16) {
len -= 16;
DO16(buf);
buf += 16;
}
while (len--) {
adler += *buf++;
sum2 += adler;
}
MOD(adler);
MOD(sum2);
}
/* return recombined sums */
return adler | (sum2 << 16);
}
/* ===========================================================================
* 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 Buf_size 16
/* size of bit buffer in bi_buf */
#define INIT_STATE 42 /* zlib header -> BUSY_STATE */
#ifdef GZIP
# define GZIP_STATE 57 /* gzip header -> BUSY_STATE | EXTRA_STATE */
#endif
#define EXTRA_STATE 69 /* gzip extra block -> NAME_STATE */
#define NAME_STATE 73 /* gzip file name -> COMMENT_STATE */
#define COMMENT_STATE 91 /* gzip comment -> HCRC_STATE */
#define HCRC_STATE 103 /* gzip header CRC -> BUSY_STATE */
#define BUSY_STATE 113 /* deflate -> FINISH_STATE */
#define FINISH_STATE 666 /* stream complete */
/* 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 */
const 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 */
ulg pending; /* nb of bytes in the pending buffer */
int wrap; /* bit 0 true for zlib, bit 1 true for gzip */
gz_headerp gzhead; /* gzip header information to write */
ulg gzindex; /* where in extra, name, or comment */
Byte method; /* can only be 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 suppress 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 */
uInt insert; /* bytes at end of window left to insert */
#ifdef ZLIB_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.
*/
ulg high_water;
/* High water mark offset in window for initialized bytes -- bytes above
* this are set to zero in order to avoid memory check warnings when
* longest match routines access bytes past the input. This is then
* updated to the new high water mark.
*/
} 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++] = (Bytef)(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.
*/
#define WIN_INIT MAX_MATCH
/* Number of bytes after end of data in window to initialize in order to avoid
memory checker errors from longest match routines */
#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) */
static const 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};
static const 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};
static const 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};
static const 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.
*/
/* ===========================================================================
* Local data. These are initialized only once.
*/
#define DIST_CODE_LEN 512 /* see definition of array dist_code below */
static const ct_data static_ltree[L_CODES+2] = {
{{ 12},{ 8}}, {{140},{ 8}}, {{ 76},{ 8}}, {{204},{ 8}}, {{ 44},{ 8}},
{{172},{ 8}}, {{108},{ 8}}, {{236},{ 8}}, {{ 28},{ 8}}, {{156},{ 8}},
{{ 92},{ 8}}, {{220},{ 8}}, {{ 60},{ 8}}, {{188},{ 8}}, {{124},{ 8}},
{{252},{ 8}}, {{ 2},{ 8}}, {{130},{ 8}}, {{ 66},{ 8}}, {{194},{ 8}},
{{ 34},{ 8}}, {{162},{ 8}}, {{ 98},{ 8}}, {{226},{ 8}}, {{ 18},{ 8}},
{{146},{ 8}}, {{ 82},{ 8}}, {{210},{ 8}}, {{ 50},{ 8}}, {{178},{ 8}},
{{114},{ 8}}, {{242},{ 8}}, {{ 10},{ 8}}, {{138},{ 8}}, {{ 74},{ 8}},
{{202},{ 8}}, {{ 42},{ 8}}, {{170},{ 8}}, {{106},{ 8}}, {{234},{ 8}},
{{ 26},{ 8}}, {{154},{ 8}}, {{ 90},{ 8}}, {{218},{ 8}}, {{ 58},{ 8}},
{{186},{ 8}}, {{122},{ 8}}, {{250},{ 8}}, {{ 6},{ 8}}, {{134},{ 8}},
{{ 70},{ 8}}, {{198},{ 8}}, {{ 38},{ 8}}, {{166},{ 8}}, {{102},{ 8}},
{{230},{ 8}}, {{ 22},{ 8}}, {{150},{ 8}}, {{ 86},{ 8}}, {{214},{ 8}},
{{ 54},{ 8}}, {{182},{ 8}}, {{118},{ 8}}, {{246},{ 8}}, {{ 14},{ 8}},
{{142},{ 8}}, {{ 78},{ 8}}, {{206},{ 8}}, {{ 46},{ 8}}, {{174},{ 8}},
{{110},{ 8}}, {{238},{ 8}}, {{ 30},{ 8}}, {{158},{ 8}}, {{ 94},{ 8}},
{{222},{ 8}}, {{ 62},{ 8}}, {{190},{ 8}}, {{126},{ 8}}, {{254},{ 8}},
{{ 1},{ 8}}, {{129},{ 8}}, {{ 65},{ 8}}, {{193},{ 8}}, {{ 33},{ 8}},
{{161},{ 8}}, {{ 97},{ 8}}, {{225},{ 8}}, {{ 17},{ 8}}, {{145},{ 8}},
{{ 81},{ 8}}, {{209},{ 8}}, {{ 49},{ 8}}, {{177},{ 8}}, {{113},{ 8}},
{{241},{ 8}}, {{ 9},{ 8}}, {{137},{ 8}}, {{ 73},{ 8}}, {{201},{ 8}},
{{ 41},{ 8}}, {{169},{ 8}}, {{105},{ 8}}, {{233},{ 8}}, {{ 25},{ 8}},
{{153},{ 8}}, {{ 89},{ 8}}, {{217},{ 8}}, {{ 57},{ 8}}, {{185},{ 8}},
{{121},{ 8}}, {{249},{ 8}}, {{ 5},{ 8}}, {{133},{ 8}}, {{ 69},{ 8}},
{{197},{ 8}}, {{ 37},{ 8}}, {{165},{ 8}}, {{101},{ 8}}, {{229},{ 8}},
{{ 21},{ 8}}, {{149},{ 8}}, {{ 85},{ 8}}, {{213},{ 8}}, {{ 53},{ 8}},
{{181},{ 8}}, {{117},{ 8}}, {{245},{ 8}}, {{ 13},{ 8}}, {{141},{ 8}},
{{ 77},{ 8}}, {{205},{ 8}}, {{ 45},{ 8}}, {{173},{ 8}}, {{109},{ 8}},
{{237},{ 8}}, {{ 29},{ 8}}, {{157},{ 8}}, {{ 93},{ 8}}, {{221},{ 8}},
{{ 61},{ 8}}, {{189},{ 8}}, {{125},{ 8}}, {{253},{ 8}}, {{ 19},{ 9}},
{{275},{ 9}}, {{147},{ 9}}, {{403},{ 9}}, {{ 83},{ 9}}, {{339},{ 9}},
{{211},{ 9}}, {{467},{ 9}}, {{ 51},{ 9}}, {{307},{ 9}}, {{179},{ 9}},
{{435},{ 9}}, {{115},{ 9}}, {{371},{ 9}}, {{243},{ 9}}, {{499},{ 9}},
{{ 11},{ 9}}, {{267},{ 9}}, {{139},{ 9}}, {{395},{ 9}}, {{ 75},{ 9}},
{{331},{ 9}}, {{203},{ 9}}, {{459},{ 9}}, {{ 43},{ 9}}, {{299},{ 9}},
{{171},{ 9}}, {{427},{ 9}}, {{107},{ 9}}, {{363},{ 9}}, {{235},{ 9}},
{{491},{ 9}}, {{ 27},{ 9}}, {{283},{ 9}}, {{155},{ 9}}, {{411},{ 9}},
{{ 91},{ 9}}, {{347},{ 9}}, {{219},{ 9}}, {{475},{ 9}}, {{ 59},{ 9}},
{{315},{ 9}}, {{187},{ 9}}, {{443},{ 9}}, {{123},{ 9}}, {{379},{ 9}},
{{251},{ 9}}, {{507},{ 9}}, {{ 7},{ 9}}, {{263},{ 9}}, {{135},{ 9}},
{{391},{ 9}}, {{ 71},{ 9}}, {{327},{ 9}}, {{199},{ 9}}, {{455},{ 9}},
{{ 39},{ 9}}, {{295},{ 9}}, {{167},{ 9}}, {{423},{ 9}}, {{103},{ 9}},
{{359},{ 9}}, {{231},{ 9}}, {{487},{ 9}}, {{ 23},{ 9}}, {{279},{ 9}},
{{151},{ 9}}, {{407},{ 9}}, {{ 87},{ 9}}, {{343},{ 9}}, {{215},{ 9}},
{{471},{ 9}}, {{ 55},{ 9}}, {{311},{ 9}}, {{183},{ 9}}, {{439},{ 9}},
{{119},{ 9}}, {{375},{ 9}}, {{247},{ 9}}, {{503},{ 9}}, {{ 15},{ 9}},
{{271},{ 9}}, {{143},{ 9}}, {{399},{ 9}}, {{ 79},{ 9}}, {{335},{ 9}},
{{207},{ 9}}, {{463},{ 9}}, {{ 47},{ 9}}, {{303},{ 9}}, {{175},{ 9}},
{{431},{ 9}}, {{111},{ 9}}, {{367},{ 9}}, {{239},{ 9}}, {{495},{ 9}},
{{ 31},{ 9}}, {{287},{ 9}}, {{159},{ 9}}, {{415},{ 9}}, {{ 95},{ 9}},
{{351},{ 9}}, {{223},{ 9}}, {{479},{ 9}}, {{ 63},{ 9}}, {{319},{ 9}},
{{191},{ 9}}, {{447},{ 9}}, {{127},{ 9}}, {{383},{ 9}}, {{255},{ 9}},
{{511},{ 9}}, {{ 0},{ 7}}, {{ 64},{ 7}}, {{ 32},{ 7}}, {{ 96},{ 7}},
{{ 16},{ 7}}, {{ 80},{ 7}}, {{ 48},{ 7}}, {{112},{ 7}}, {{ 8},{ 7}},
{{ 72},{ 7}}, {{ 40},{ 7}}, {{104},{ 7}}, {{ 24},{ 7}}, {{ 88},{ 7}},
{{ 56},{ 7}}, {{120},{ 7}}, {{ 4},{ 7}}, {{ 68},{ 7}}, {{ 36},{ 7}},
{{100},{ 7}}, {{ 20},{ 7}}, {{ 84},{ 7}}, {{ 52},{ 7}}, {{116},{ 7}},
{{ 3},{ 8}}, {{131},{ 8}}, {{ 67},{ 8}}, {{195},{ 8}}, {{ 35},{ 8}},
{{163},{ 8}}, {{ 99},{ 8}}, {{227},{ 8}}
};
static const ct_data static_dtree[D_CODES] = {
{{ 0},{ 5}}, {{16},{ 5}}, {{ 8},{ 5}}, {{24},{ 5}}, {{ 4},{ 5}},
{{20},{ 5}}, {{12},{ 5}}, {{28},{ 5}}, {{ 2},{ 5}}, {{18},{ 5}},
{{10},{ 5}}, {{26},{ 5}}, {{ 6},{ 5}}, {{22},{ 5}}, {{14},{ 5}},
{{30},{ 5}}, {{ 1},{ 5}}, {{17},{ 5}}, {{ 9},{ 5}}, {{25},{ 5}},
{{ 5},{ 5}}, {{21},{ 5}}, {{13},{ 5}}, {{29},{ 5}}, {{ 3},{ 5}},
{{19},{ 5}}, {{11},{ 5}}, {{27},{ 5}}, {{ 7},{ 5}}, {{23},{ 5}}
};
static const uch _dist_code[DIST_CODE_LEN] = {
0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8,
8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 0, 0, 16, 17,
18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
};
static const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {
0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28
};
static const int base_length[LENGTH_CODES] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
64, 80, 96, 112, 128, 160, 192, 224, 0
};
static const int base_dist[D_CODES] = {
0, 1, 2, 3, 4, 6, 8, 12, 16, 24,
32, 48, 64, 96, 128, 192, 256, 384, 512, 768,
1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384, 24576
};
struct static_tree_desc_s {
const ct_data *static_tree; /* static tree or NULL */
const 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 */
};
static const static_tree_desc static_l_desc =
{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
static const static_tree_desc static_d_desc =
{static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
static const static_tree_desc static_bl_desc =
{(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
#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 */
#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.
*/
# 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 = (uch)(length); \
ush dist = (ush)(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); \
}
/* ===========================================================================
* 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)); \
}
#define send_bits(s, value, length) \
{ int len = length;\
if (s->bi_valid > (int)Buf_size - len) {\
int val = (int)value;\
s->bi_buf |= (ush)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 |= (ush)(value) << s->bi_valid;\
s->bi_valid += len;\
}\
}
/* ===========================================================================
* Send the block data compressed using the given Huffman trees
*/
static void compress_block( deflate_state *s, const ct_data *ltree, const ct_data *dtree )
{
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 -= (unsigned)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((uInt)(s->pending) < s->lit_bufsize + 2*lx,
"pendingBuf overflow");
} while (lx < s->last_lit);
send_code(s, END_BLOCK, ltree);
}
/* ===========================================================================
* Check if the data type is TEXT or BINARY, using the following algorithm:
* - TEXT if the two conditions below are satisfied:
* a) There are no non-portable control characters belonging to the
* "black list" (0..6, 14..25, 28..31).
* b) There is at least one printable character belonging to the
* "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
* - BINARY otherwise.
* - The following partially-portable control characters form a
* "gray list" that is ignored in this detection algorithm:
* (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
* IN assertion: the fields Freq of dyn_ltree are set.
*/
static int detect_data_type( deflate_state *s )
{
/* black_mask is the bit mask of black-listed bytes
* set bits 0..6, 14..25, and 28..31
* 0xf3ffc07f = binary 11110011111111111100000001111111
*/
unsigned long black_mask = 0xf3ffc07fUL;
int n;
/* Check for non-textual ("black-listed") bytes. */
for (n = 0; n <= 31; n++, black_mask >>= 1)
if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
return Z_BINARY;
/* Check for textual ("white-listed") bytes. */
if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
|| s->dyn_ltree[13].Freq != 0)
return Z_TEXT;
for (n = 32; n < LITERALS; n++)
if (s->dyn_ltree[n].Freq != 0)
return Z_TEXT;
/* There are no "black-listed" or "white-listed" bytes:
* this stream either is empty or has tolerated ("gray-listed") bytes only.
*/
return Z_BINARY;
}
/* ===========================================================================
* Reverse the first len bits of a code, using straightforward code (a faster
* method would use a table)
* IN assertion: 1 <= len <= 15
*/
static unsigned bi_reverse( unsigned code, int len )
{
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.
*/
static void bi_flush( 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
*/
static void bi_windup( 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 ZLIB_DEBUG
s->bits_sent = (s->bits_sent+7) & ~7;
#endif
}
/* ===========================================================================
* Initialize a new block.
*/
static void init_block( 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;
}
/* ===========================================================================
* Initialize the tree data structures for a new zlib stream.
*/
static void _tr_init( deflate_state *s )
{
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;
#ifdef ZLIB_DEBUG
s->compressed_len = 0L;
s->bits_sent = 0L;
#endif
/* Initialize the first block of the first file: */
init_block(s);
}
#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).
*/
static void pqdownheap( deflate_state *s, ct_data *tree, int k )
{
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.
*/
static void gen_bitlen( deflate_state *s, tree_desc *desc )
{
ct_data *tree = desc->dyn_tree;
int max_code = desc->max_code;
const ct_data *stree = desc->stat_desc->static_tree;
const 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 * (unsigned)(bits + xbits);
if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits);
}
if (overflow == 0) return;
Tracev((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 ((unsigned) tree[m].Len != (unsigned) bits) {
Tracev((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
s->opt_len += ((ulg)bits - tree[m].Len) * 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.
*/
static void gen_codes( ct_data *tree, int max_code, ushf *bl_count )
{
ush next_code[MAX_BITS+1]; /* next code value for each bit length */
unsigned 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++) {
code = (code + bl_count[bits-1]) << 1;
next_code[bits] = (ush)code;
}
/* 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 = (ush)bi_reverse(next_code[len]++, len);
Tracecv(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.
*/
static void build_tree( deflate_state *s, tree_desc *desc )
{
ct_data *tree = desc->dyn_tree;
const 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)((s->depth[n] >= s->depth[m] ?
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.
*/
static void scan_tree( deflate_state *s, ct_data *tree, int max_code )
{
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.
*/
static void send_tree( deflate_state *s, ct_data *tree, int max_code )
{
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.
*/
static int build_bl_tree( 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*((ulg)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.
*/
static void send_all_trees( deflate_state *s, int lcodes, int dcodes, int blcodes )
{
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
*/
static void _tr_stored_block( deflate_state *s, charf *buf, ulg stored_len, int last )
{
send_bits(s, (STORED_BLOCK<<1)+last, 3); /* send block type */
bi_windup(s); /* align on byte boundary */
put_short(s, (ush)stored_len);
put_short(s, (ush)~stored_len);
zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
s->pending += stored_len;
#ifdef ZLIB_DEBUG
s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
s->compressed_len += (stored_len + 4) << 3;
s->bits_sent += 2*16;
s->bits_sent += stored_len<<3;
#endif
}
/* ===========================================================================
* Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
*/
static void _tr_flush_bits( deflate_state *s )
{
bi_flush(s);
}
/* ===========================================================================
* Send one empty static block to give enough lookahead for inflate.
* This takes 10 bits, of which 7 may remain in the bit buffer.
*/
static void _tr_align( deflate_state *s )
{
send_bits(s, STATIC_TREES<<1, 3);
send_code(s, END_BLOCK, static_ltree);
#ifdef ZLIB_DEBUG
s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
#endif
bi_flush(s);
}
/* ===========================================================================
* Determine the best encoding for the current block: dynamic trees, static
* trees or store, and write out the encoded block.
*/
static void _tr_flush_block( deflate_state *s, charf *buf, ulg stored_len, int last )
{
ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
int max_blindex = 0; /* index of last bit length code of non zero freq */
/* Build the Huffman trees unless a stored block is forced */
if (s->level > 0) {
/* Check if the file is binary or text */
if (s->strm->data_type == Z_UNKNOWN)
s->strm->data_type = detect_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 the block lengths 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;
} else {
Assert(buf != (char*)0, "lost buf");
opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
}
#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.
*/
_tr_stored_block(s, buf, stored_len, last);
#ifdef FORCE_STATIC
} else if (static_lenb >= 0) { /* force static trees */
#else
} else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
#endif
send_bits(s, (STATIC_TREES<<1)+last, 3);
compress_block(s, (const ct_data *)static_ltree,
(const ct_data *)static_dtree);
#ifdef ZLIB_DEBUG
s->compressed_len += 3 + s->static_len;
#endif
} else {
send_bits(s, (DYN_TREES<<1)+last, 3);
send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
max_blindex+1);
compress_block(s, (const ct_data *)s->dyn_ltree,
(const ct_data *)s->dyn_dtree);
#ifdef ZLIB_DEBUG
s->compressed_len += 3 + s->opt_len;
#endif
}
Assert (s->compressed_len == s->bits_sent, "bad compressed size");
/* The above check is made mod 2^32, for files larger than 512 MB
* and uLong implemented on 32 bits.
*/
init_block(s);
if (last) {
bi_windup(s);
#ifdef ZLIB_DEBUG
s->compressed_len += 7; /* align on byte boundary */
#endif
}
Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
s->compressed_len-7*last));
}
const char deflate_copyright[] =
" deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
/*
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.
*/
/* ===========================================================================
* Function prototypes.
*/
typedef enum {
need_more, /* block not completed, need more input or more output */
block_done, /* block flush performed */
finish_started, /* finish started, need only more output at next deflate */
finish_done /* finish done, accept no more input or output */
} block_state;
typedef block_state (*compress_func)(deflate_state *s, int flush);
/* Compression function. Returns the block state after the call. */
static int deflateReset(z_streamp strm);
static block_state deflate_stored(deflate_state *s, int flush);
static block_state deflate_fast(deflate_state *s, int flush);
static block_state deflate_slow(deflate_state *s, int flush);
static block_state deflate_rle(deflate_state *s, int flush);
static block_state deflate_huff(deflate_state *s, int flush);
static void lm_init(deflate_state *s);
/* ===========================================================================
* Local data
*/
#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 */
/* 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;
compress_func func;
} config;
static const config configuration_table[10] = {
/* good lazy nice chain */
/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
/* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */
/* 2 */ {4, 5, 16, 8, deflate_fast},
/* 3 */ {4, 6, 32, 32, deflate_fast},
/* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
/* 5 */ {8, 16, 32, 32, deflate_slow},
/* 6 */ {8, 16, 128, 128, deflate_slow},
/* 7 */ {8, 32, 128, 256, deflate_slow},
/* 8 */ {32, 128, 258, 1024, deflate_slow},
/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max 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.
*/
/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
#define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0))
/* ===========================================================================
* Update a hash value with the given input byte
* IN assertion: all calls 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.
* If this file is compiled with -DFASTEST, the compression level is forced
* to 1, and no hash chains are maintained.
* IN assertion: all calls 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).
*/
#ifdef FASTEST
#define INSERT_STRING(s, str, match_head) \
(UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
match_head = s->head[s->ins_h], \
s->head[s->ins_h] = (Pos)(str))
#else
#define INSERT_STRING(s, str, match_head) \
(UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
s->head[s->ins_h] = (Pos)(str))
#endif
/* ===========================================================================
* 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((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
/* ===========================================================================
* Slide the hash table when sliding the window down (could be avoided with 32
* bit values at the expense of memory usage). We slide even when level == 0 to
* keep the hash table consistent if we switch back to level > 0 later.
*/
static void slide_hash( deflate_state *s )
{
unsigned n, m;
Posf *p;
uInt wsize = s->w_size;
n = s->hash_size;
p = &s->head[n];
do {
m = *--p;
*p = (Pos)(m >= wsize ? m - wsize : NIL);
} while (--n);
n = wsize;
#ifndef FASTEST
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);
#endif
}
/* ========================================================================= */
int deflateInit( z_streamp strm, int level )
{
return deflateInit2(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
/* To do: ignore strm->next_in if we use it as window */
}
/* ========================================================================= */
int deflateInit2( z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy )
{
deflate_state *s;
int wrap = 1;
ushf *overlay;
/* We overlay pending_buf and d_buf+l_buf. This works since the average
* output size for (length,distance) codes is <= 24 bits.
*/
strm->msg = Z_NULL;
#ifdef FASTEST
if (level != 0) level = 1;
#else
if (level == Z_DEFAULT_COMPRESSION) level = 6;
#endif
if (windowBits < 0) { /* suppress zlib wrapper */
wrap = 0;
windowBits = -windowBits;
}
#ifdef GZIP
else if (windowBits > 15) {
wrap = 2; /* write gzip wrapper instead */
windowBits -= 16;
}
#endif
if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
return Z_STREAM_ERROR;
}
if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */
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->status = INIT_STATE; /* to pass state test in deflateReset() */
s->wrap = wrap;
s->gzhead = Z_NULL;
s->w_bits = (uInt)windowBits;
s->w_size = 1 << s->w_bits;
s->w_mask = s->w_size - 1;
s->hash_bits = (uInt)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->high_water = 0; /* nothing written to s->window yet */
s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
s->pending_buf = (uchf *) overlay;
s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
s->pending_buf == Z_NULL) {
s->status = FINISH_STATE;
strm->msg = ERR_MSG(Z_MEM_ERROR);
deflateEnd (strm);
return Z_MEM_ERROR;
}
s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
s->level = level;
s->strategy = strategy;
s->method = (Byte)method;
return deflateReset(strm);
}
/* =========================================================================
* Check for a valid deflate stream state. Return 0 if ok, 1 if not.
*/
static int deflateStateCheck( z_streamp strm )
{
deflate_state *s;
if (strm == Z_NULL ||
strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
return 1;
s = strm->state;
if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
#ifdef GZIP
s->status != GZIP_STATE &&
#endif
s->status != EXTRA_STATE &&
s->status != NAME_STATE &&
s->status != COMMENT_STATE &&
s->status != HCRC_STATE &&
s->status != BUSY_STATE &&
s->status != FINISH_STATE))
return 1;
return 0;
}
/* ========================================================================= */
static int deflateResetKeep( z_streamp strm )
{
deflate_state *s;
if (deflateStateCheck(strm)) {
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->wrap < 0) {
s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
}
s->status =
#ifdef GZIP
s->wrap == 2 ? GZIP_STATE :
#endif
s->wrap ? INIT_STATE : BUSY_STATE;
strm->adler =
#ifdef GZIP
s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
#endif
adler32(0L, Z_NULL, 0);
s->last_flush = Z_NO_FLUSH;
_tr_init(s);
return Z_OK;
}
/* ========================================================================= */
static int deflateReset( z_streamp strm )
{
int ret;
ret = deflateResetKeep(strm);
if (ret == Z_OK)
lm_init(strm->state);
return ret;
}
/* =========================================================================
* 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.
*/
static void putShortMSB( deflate_state *s, uInt b )
{
put_byte(s, (Byte)(b >> 8));
put_byte(s, (Byte)(b & 0xff));
}
/* =========================================================================
* Flush as much pending output as possible. All deflate() output, except for
* some deflate_stored() output, goes through this function so some
* applications may wish to modify it to avoid allocating a large
* strm->next_out buffer and copying into it. (See also read_buf()).
*/
static void flush_pending( z_streamp strm )
{
unsigned len;
deflate_state *s = strm->state;
_tr_flush_bits(s);
len = s->pending;
if (len > strm->avail_out) len = strm->avail_out;
if (len == 0) return;
zmemcpy(strm->next_out, s->pending_out, len);
strm->next_out += len;
s->pending_out += len;
strm->total_out += len;
strm->avail_out -= len;
s->pending -= len;
if (s->pending == 0) {
s->pending_out = s->pending_buf;
}
}
/* ===========================================================================
* Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1].
*/
#define HCRC_UPDATE(beg) \
do { \
if (s->gzhead->hcrc && s->pending > (beg)) \
strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
s->pending - (beg)); \
} while (0)
/* ========================================================================= */
int deflate( z_streamp strm, int flush )
{
int old_flush; /* value of flush param for previous deflate call */
deflate_state *s;
if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
return Z_STREAM_ERROR;
}
s = strm->state;
if (strm->next_out == Z_NULL ||
(strm->avail_in != 0 && strm->next_in == Z_NULL) ||
(s->status == FINISH_STATE && flush != Z_FINISH)) {
ERR_RETURN(strm, Z_STREAM_ERROR);
}
if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
old_flush = s->last_flush;
s->last_flush = flush;
/* Flush as much pending output as possible */
if (s->pending != 0) {
flush_pending(strm);
if (strm->avail_out == 0) {
/* Since avail_out is 0, deflate will be called again with
* more output space, but possibly with both pending and
* avail_in equal to zero. There won't be anything to do,
* but this is not an error situation so make sure we
* return OK instead of BUF_ERROR at next call of deflate:
*/
s->last_flush = -1;
return Z_OK;
}
/* Make sure there is something to do and avoid duplicate consecutive
* flushes. For repeated and useless calls with Z_FINISH, we keep
* returning Z_STREAM_END instead of Z_BUF_ERROR.
*/
} else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
flush != Z_FINISH) {
ERR_RETURN(strm, Z_BUF_ERROR);
}
/* User must not provide more input after the first FINISH: */
if (s->status == FINISH_STATE && strm->avail_in != 0) {
ERR_RETURN(strm, Z_BUF_ERROR);
}
/* Write the header */
if (s->status == INIT_STATE) {
/* zlib header */
uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
uInt level_flags;
if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
level_flags = 0;
else if (s->level < 6)
level_flags = 1;
else if (s->level == 6)
level_flags = 2;
else
level_flags = 3;
header |= (level_flags << 6);
if (s->strstart != 0) header |= PRESET_DICT;
header += 31 - (header % 31);
putShortMSB(s, header);
/* Save the adler32 of the preset dictionary: */
if (s->strstart != 0) {
putShortMSB(s, (uInt)(strm->adler >> 16));
putShortMSB(s, (uInt)(strm->adler & 0xffff));
}
strm->adler = adler32(0L, Z_NULL, 0);
s->status = BUSY_STATE;
/* Compression must start with an empty pending buffer */
flush_pending(strm);
if (s->pending != 0) {
s->last_flush = -1;
return Z_OK;
}
}
#ifdef GZIP
if (s->status == GZIP_STATE) {
/* gzip header */
strm->adler = crc32(0L, Z_NULL, 0);
put_byte(s, 31);
put_byte(s, 139);
put_byte(s, 8);
if (s->gzhead == Z_NULL) {
put_byte(s, 0);
put_byte(s, 0);
put_byte(s, 0);
put_byte(s, 0);
put_byte(s, 0);
put_byte(s, s->level == 9 ? 2 :
(s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
4 : 0));
put_byte(s, OS_CODE);
s->status = BUSY_STATE;
/* Compression must start with an empty pending buffer */
flush_pending(strm);
if (s->pending != 0) {
s->last_flush = -1;
return Z_OK;
}
}
else {
put_byte(s, (s->gzhead->text ? 1 : 0) +
(s->gzhead->hcrc ? 2 : 0) +
(s->gzhead->extra == Z_NULL ? 0 : 4) +
(s->gzhead->name == Z_NULL ? 0 : 8) +
(s->gzhead->comment == Z_NULL ? 0 : 16)
);
put_byte(s, (Byte)(s->gzhead->time & 0xff));
put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
put_byte(s, s->level == 9 ? 2 :
(s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
4 : 0));
put_byte(s, s->gzhead->os & 0xff);
if (s->gzhead->extra != Z_NULL) {
put_byte(s, s->gzhead->extra_len & 0xff);
put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
}
if (s->gzhead->hcrc)
strm->adler = crc32(strm->adler, s->pending_buf,
s->pending);
s->gzindex = 0;
s->status = EXTRA_STATE;
}
}
if (s->status == EXTRA_STATE) {
if (s->gzhead->extra != Z_NULL) {
ulg beg = s->pending; /* start of bytes to update crc */
uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
while (s->pending + left > s->pending_buf_size) {
uInt copy = s->pending_buf_size - s->pending;
zmemcpy(s->pending_buf + s->pending,
s->gzhead->extra + s->gzindex, copy);
s->pending = s->pending_buf_size;
HCRC_UPDATE(beg);
s->gzindex += copy;
flush_pending(strm);
if (s->pending != 0) {
s->last_flush = -1;
return Z_OK;
}
beg = 0;
left -= copy;
}
zmemcpy(s->pending_buf + s->pending,
s->gzhead->extra + s->gzindex, left);
s->pending += left;
HCRC_UPDATE(beg);
s->gzindex = 0;
}
s->status = NAME_STATE;
}
if (s->status == NAME_STATE) {
if (s->gzhead->name != Z_NULL) {
ulg beg = s->pending; /* start of bytes to update crc */
int val;
do {
if (s->pending == s->pending_buf_size) {
HCRC_UPDATE(beg);
flush_pending(strm);
if (s->pending != 0) {
s->last_flush = -1;
return Z_OK;
}
beg = 0;
}
val = s->gzhead->name[s->gzindex++];
put_byte(s, val);
} while (val != 0);
HCRC_UPDATE(beg);
s->gzindex = 0;
}
s->status = COMMENT_STATE;
}
if (s->status == COMMENT_STATE) {
if (s->gzhead->comment != Z_NULL) {
ulg beg = s->pending; /* start of bytes to update crc */
int val;
do {
if (s->pending == s->pending_buf_size) {
HCRC_UPDATE(beg);
flush_pending(strm);
if (s->pending != 0) {
s->last_flush = -1;
return Z_OK;
}
beg = 0;
}
val = s->gzhead->comment[s->gzindex++];
put_byte(s, val);
} while (val != 0);
HCRC_UPDATE(beg);
}
s->status = HCRC_STATE;
}
if (s->status == HCRC_STATE) {
if (s->gzhead->hcrc) {
if (s->pending + 2 > s->pending_buf_size) {
flush_pending(strm);
if (s->pending != 0) {
s->last_flush = -1;
return Z_OK;
}
}
put_byte(s, (Byte)(strm->adler & 0xff));
put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
strm->adler = crc32(0L, Z_NULL, 0);
}
s->status = BUSY_STATE;
/* Compression must start with an empty pending buffer */
flush_pending(strm);
if (s->pending != 0) {
s->last_flush = -1;
return Z_OK;
}
}
#endif
/* Start a new block or continue the current one.
*/
if (strm->avail_in != 0 || s->lookahead != 0 ||
(flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
block_state bstate;
bstate = s->level == 0 ? deflate_stored(s, flush) :
s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
s->strategy == Z_RLE ? deflate_rle(s, flush) :
(*(configuration_table[s->level].func))(s, flush);
if (bstate == finish_started || bstate == finish_done) {
s->status = FINISH_STATE;
}
if (bstate == need_more || bstate == finish_started) {
if (strm->avail_out == 0) {
s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
}
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 (bstate == block_done) {
if (flush == Z_PARTIAL_FLUSH) {
_tr_align(s);
} else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
_tr_stored_block(s, (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(s); /* forget history */
if (s->lookahead == 0) {
s->strstart = 0;
s->block_start = 0L;
s->insert = 0;
}
}
}
flush_pending(strm);
if (strm->avail_out == 0) {
s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
return Z_OK;
}
}
}
if (flush != Z_FINISH) return Z_OK;
if (s->wrap <= 0) return Z_STREAM_END;
/* Write the trailer */
#ifdef GZIP
if (s->wrap == 2) {
put_byte(s, (Byte)(strm->adler & 0xff));
put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
put_byte(s, (Byte)(strm->total_in & 0xff));
put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
}
else
#endif
{
putShortMSB(s, (uInt)(strm->adler >> 16));
putShortMSB(s, (uInt)(strm->adler & 0xffff));
}
flush_pending(strm);
/* If avail_out is zero, the application will call deflate again
* to flush the rest.
*/
if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
return s->pending != 0 ? Z_OK : Z_STREAM_END;
}
/* ========================================================================= */
int deflateEnd( z_streamp strm )
{
int status;
if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
status = strm->state->status;
/* Deallocate in reverse order of allocations: */
TRY_FREE(strm, strm->state->pending_buf);
TRY_FREE(strm, strm->state->head);
TRY_FREE(strm, strm->state->prev);
TRY_FREE(strm, strm->state->window);
ZFREE(strm, strm->state);
strm->state = Z_NULL;
return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
}
/* ===========================================================================
* Read a new buffer from the current input stream, update the adler32
* and total number of bytes read. All deflate() input goes through
* this function so some applications may wish to modify it to avoid
* allocating a large strm->next_in buffer and copying from it.
* (See also flush_pending()).
*/
static unsigned read_buf( z_streamp strm, Bytef *buf, unsigned size )
{
unsigned len = strm->avail_in;
if (len > size) len = size;
if (len == 0) return 0;
strm->avail_in -= len;
zmemcpy(buf, strm->next_in, len);
if (strm->state->wrap == 1) {
strm->adler = adler32(strm->adler, buf, len);
}
#ifdef GZIP
else if (strm->state->wrap == 2) {
strm->adler = crc32(strm->adler, buf, len);
}
#endif
strm->next_in += len;
strm->total_in += len;
return len;
}
/* ===========================================================================
* Initialize the "longest match" routines for a new zlib stream
*/
static void lm_init( 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->insert = 0;
s->match_length = s->prev_length = MIN_MATCH-1;
s->match_available = 0;
s->ins_h = 0;
}
/* ===========================================================================
* 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
* OUT assertion: the match length is not greater than s->lookahead.
*/
static uInt longest_match( deflate_state *s, IPos cur_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 = (int)s->prev_length; /* best match length so far */
int nice_match = s->nice_match; /* stop if match long enough */
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;
}
/* Do not look for matches beyond the end of the input. This is necessary
* to make deflate deterministic.
*/
if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
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. Note that the checks below
* for insufficient lookahead only occur occasionally for performance
* reasons. Therefore uninitialized memory will be accessed, and
* conditional jumps will be made that depend on those values.
* However the length of the match is limited to the lookahead, so
* the output of deflate is not affected by the uninitialized values.
*/
#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 >= 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);
if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
return s->lookahead;
}
#define check_match(s, start, match, length)
/* ===========================================================================
* 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).
*/
static void fill_window( deflate_state *s )
{
unsigned n;
unsigned more; /* Amount of free space at the end of the window. */
uInt wsize = s->w_size;
Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
do {
more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
/* Deal with !@#$% 64K limit: */
if (sizeof(int) <= 2) {
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 && lookahead == 1 (input done a 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.
*/
if (s->strstart >= wsize+MAX_DIST(s)) {
zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more);
s->match_start -= wsize;
s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
s->block_start -= (long) wsize;
slide_hash(s);
more += wsize;
}
if (s->strm->avail_in == 0) break;
/* 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, s->window + s->strstart + s->lookahead, more);
s->lookahead += n;
/* Initialize the hash value now that we have some input: */
if (s->lookahead + s->insert >= MIN_MATCH) {
uInt str = s->strstart - s->insert;
s->ins_h = s->window[str];
UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
#if MIN_MATCH != 3
Call UPDATE_HASH() MIN_MATCH-3 more times
#endif
while (s->insert) {
UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
#ifndef FASTEST
s->prev[str & s->w_mask] = s->head[s->ins_h];
#endif
s->head[s->ins_h] = (Pos)str;
str++;
s->insert--;
if (s->lookahead + s->insert < MIN_MATCH)
break;
}
}
/* 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);
/* If the WIN_INIT bytes after the end of the current data have never been
* written, then zero those bytes in order to avoid memory check reports of
* the use of uninitialized (or uninitialised as Julian writes) bytes by
* the longest match routines. Update the high water mark for the next
* time through here. WIN_INIT is set to MAX_MATCH since the longest match
* routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
*/
if (s->high_water < s->window_size) {
ulg curr = s->strstart + (ulg)(s->lookahead);
ulg init;
if (s->high_water < curr) {
/* Previous high water mark below current data -- zero WIN_INIT
* bytes or up to end of window, whichever is less.
*/
init = s->window_size - curr;
if (init > WIN_INIT)
init = WIN_INIT;
zmemzero(s->window + curr, (unsigned)init);
s->high_water = curr + init;
}
else if (s->high_water < (ulg)curr + WIN_INIT) {
/* High water mark at or above current data, but below current data
* plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
* to end of window, whichever is less.
*/
init = (ulg)curr + WIN_INIT - s->high_water;
if (init > s->window_size - s->high_water)
init = s->window_size - s->high_water;
zmemzero(s->window + s->high_water, (unsigned)init);
s->high_water += init;
}
}
Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
"not enough room for search");
}
/* ===========================================================================
* 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, last) { \
_tr_flush_block(s, (s->block_start >= 0L ? \
(charf *)&s->window[(unsigned)s->block_start] : \
(charf *)Z_NULL), \
(ulg)((long)s->strstart - s->block_start), \
(last)); \
s->block_start = s->strstart; \
flush_pending(s->strm); \
Tracev((stderr,"[FLUSH]")); \
}
/* Same but force premature exit if necessary. */
#define FLUSH_BLOCK(s, last) { \
FLUSH_BLOCK_ONLY(s, last); \
if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
}
/* Maximum stored block length in deflate format (not including header). */
#define MAX_STORED 65535
/* Minimum of a and b. */
#define MIN(a, b) ((a) > (b) ? (b) : (a))
/* ===========================================================================
* Copy without compression as much as possible from the input stream, return
* the current block state.
*
* In case deflateParams() is used to later switch to a non-zero compression
* level, s->matches (otherwise unused when storing) keeps track of the number
* of hash table slides to perform. If s->matches is 1, then one hash table
* slide will be done when switching. If s->matches is 2, the maximum value
* allowed here, then the hash table will be cleared, since two or more slides
* is the same as a clear.
*
* deflate_stored() is written to minimize the number of times an input byte is
* copied. It is most efficient with large input and output buffers, which
* maximizes the opportunites to have a single copy from next_in to next_out.
*/
static block_state deflate_stored( deflate_state *s, int flush )
{
/* Smallest worthy block size when not flushing or finishing. By default
* this is 32K. This can be as small as 507 bytes for memLevel == 1. For
* large input and output buffers, the stored block size will be larger.
*/
unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);
/* Copy as many min_block or larger stored blocks directly to next_out as
* possible. If flushing, copy the remaining available input to next_out as
* stored blocks, if there is enough space.
*/
unsigned len, left, have, last = 0;
unsigned used = s->strm->avail_in;
do {
/* Set len to the maximum size block that we can copy directly with the
* available input data and output space. Set left to how much of that
* would be copied from what's left in the window.
*/
len = MAX_STORED; /* maximum deflate stored block length */
have = (s->bi_valid + 42) >> 3; /* number of header bytes */
if (s->strm->avail_out < have) /* need room for header */
break;
/* maximum stored block length that will fit in avail_out: */
have = s->strm->avail_out - have;
left = s->strstart - s->block_start; /* bytes left in window */
if (len > (ulg)left + s->strm->avail_in)
len = left + s->strm->avail_in; /* limit len to the input */
if (len > have)
len = have; /* limit len to the output */
/* If the stored block would be less than min_block in length, or if
* unable to copy all of the available input when flushing, then try
* copying to the window and the pending buffer instead. Also don't
* write an empty block when flushing -- deflate() does that.
*/
if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
flush == Z_NO_FLUSH ||
len != left + s->strm->avail_in))
break;
/* Make a dummy stored block in pending to get the header bytes,
* including any pending bits. This also updates the debugging counts.
*/
last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
_tr_stored_block(s, (char *)0, 0L, last);
/* Replace the lengths in the dummy stored block with len. */
s->pending_buf[s->pending - 4] = len;
s->pending_buf[s->pending - 3] = len >> 8;
s->pending_buf[s->pending - 2] = ~len;
s->pending_buf[s->pending - 1] = ~len >> 8;
/* Write the stored block header bytes. */
flush_pending(s->strm);
#ifdef ZLIB_DEBUG
/* Update debugging counts for the data about to be copied. */
s->compressed_len += len << 3;
s->bits_sent += len << 3;
#endif
/* Copy uncompressed bytes from the window to next_out. */
if (left) {
if (left > len)
left = len;
zmemcpy(s->strm->next_out, s->window + s->block_start, left);
s->strm->next_out += left;
s->strm->avail_out -= left;
s->strm->total_out += left;
s->block_start += left;
len -= left;
}
/* Copy uncompressed bytes directly from next_in to next_out, updating
* the check value.
*/
if (len) {
read_buf(s->strm, s->strm->next_out, len);
s->strm->next_out += len;
s->strm->avail_out -= len;
s->strm->total_out += len;
}
} while (last == 0);
/* Update the sliding window with the last s->w_size bytes of the copied
* data, or append all of the copied data to the existing window if less
* than s->w_size bytes were copied. Also update the number of bytes to
* insert in the hash tables, in the event that deflateParams() switches to
* a non-zero compression level.
*/
used -= s->strm->avail_in; /* number of input bytes directly copied */
if (used) {
/* If any input was used, then no unused input remains in the window,
* therefore s->block_start == s->strstart.
*/
if (used >= s->w_size) { /* supplant the previous history */
s->matches = 2; /* clear hash */
zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
s->strstart = s->w_size;
}
else {
if (s->window_size - s->strstart <= used) {
/* Slide the window down. */
s->strstart -= s->w_size;
zmemcpy(s->window, s->window + s->w_size, s->strstart);
if (s->matches < 2)
s->matches++; /* add a pending slide_hash() */
}
zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
s->strstart += used;
}
s->block_start = s->strstart;
s->insert += MIN(used, s->w_size - s->insert);
}
if (s->high_water < s->strstart)
s->high_water = s->strstart;
/* If the last block was written to next_out, then done. */
if (last)
return finish_done;
/* If flushing and all input has been consumed, then done. */
if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
return block_done;
/* Fill the window with any remaining input. */
have = s->window_size - s->strstart - 1;
if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) {
/* Slide the window down. */
s->block_start -= s->w_size;
s->strstart -= s->w_size;
zmemcpy(s->window, s->window + s->w_size, s->strstart);
if (s->matches < 2)
s->matches++; /* add a pending slide_hash() */
have += s->w_size; /* more space now */
}
if (have > s->strm->avail_in)
have = s->strm->avail_in;
if (have) {
read_buf(s->strm, s->window + s->strstart, have);
s->strstart += have;
}
if (s->high_water < s->strstart)
s->high_water = s->strstart;
/* There was not enough avail_out to write a complete worthy or flushed
* stored block to next_out. Write a stored block to pending instead, if we
* have enough input for a worthy block, or if flushing and there is enough
* room for the remaining input as a stored block in the pending buffer.
*/
have = (s->bi_valid + 42) >> 3; /* number of header bytes */
/* maximum stored block length that will fit in pending: */
have = MIN(s->pending_buf_size - have, MAX_STORED);
min_block = MIN(have, s->w_size);
left = s->strstart - s->block_start;
if (left >= min_block ||
((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
s->strm->avail_in == 0 && left <= have)) {
len = MIN(left, have);
last = flush == Z_FINISH && s->strm->avail_in == 0 &&
len == left ? 1 : 0;
_tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
s->block_start += len;
flush_pending(s->strm);
}
/* We've done all we can with the available input and output. */
return last ? finish_started : need_more;
}
/* ===========================================================================
* Compress as much as possible from the input stream, return the current
* block state.
* This function does not perform lazy evaluation of 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.
*/
static block_state deflate_fast( deflate_state *s, int flush )
{
IPos hash_head; /* head of the hash chain */
int bflush; /* set if current block must be flushed */
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 need_more;
}
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:
*/
hash_head = NIL;
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).
*/
s->match_length = longest_match (s, hash_head);
/* longest_match() sets match_start */
}
if (s->match_length >= MIN_MATCH) {
check_match(s, s->strstart, s->match_start, s->match_length);
_tr_tally_dist(s, s->strstart - s->match_start,
s->match_length - MIN_MATCH, bflush);
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.
*/
#ifndef FASTEST
if (s->match_length <= s->max_insert_length &&
s->lookahead >= MIN_MATCH) {
s->match_length--; /* string at strstart already in 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
#endif
{
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]));
_tr_tally_lit (s, s->window[s->strstart], bflush);
s->lookahead--;
s->strstart++;
}
if (bflush) FLUSH_BLOCK(s, 0);
}
s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
if (flush == Z_FINISH) {
FLUSH_BLOCK(s, 1);
return finish_done;
}
if (s->last_lit)
FLUSH_BLOCK(s, 0);
return block_done;
}
/* ===========================================================================
* 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.
*/
static block_state deflate_slow( deflate_state *s, int flush )
{
IPos hash_head; /* 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 need_more;
}
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:
*/
hash_head = NIL;
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).
*/
s->match_length = longest_match (s, hash_head);
/* longest_match() sets match_start */
if (s->match_length <= 5 && (s->strategy == Z_FILTERED
#if TOO_FAR <= 32767
|| (s->match_length == MIN_MATCH &&
s->strstart - s->match_start > TOO_FAR)
#endif
)) {
/* 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);
_tr_tally_dist(s, s->strstart -1 - s->prev_match,
s->prev_length - MIN_MATCH, bflush);
/* 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, 0);
} 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]));
_tr_tally_lit(s, s->window[s->strstart-1], bflush);
if (bflush) {
FLUSH_BLOCK_ONLY(s, 0);
}
s->strstart++;
s->lookahead--;
if (s->strm->avail_out == 0) return need_more;
} 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]));
_tr_tally_lit(s, s->window[s->strstart-1], bflush);
s->match_available = 0;
}
s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
if (flush == Z_FINISH) {
FLUSH_BLOCK(s, 1);
return finish_done;
}
if (s->last_lit)
FLUSH_BLOCK(s, 0);
return block_done;
}
/* ===========================================================================
* For Z_RLE, simply look for runs of bytes, generate matches only of distance
* one. Do not maintain a hash table. (It will be regenerated if this run of
* deflate switches away from Z_RLE.)
*/
static block_state deflate_rle( deflate_state *s, int flush )
{
int bflush; /* set if current block must be flushed */
uInt prev; /* byte at distance one to match */
Bytef *scan, *strend; /* scan goes up to strend for length of run */
for (;;) {
/* Make sure that we always have enough lookahead, except
* at the end of the input file. We need MAX_MATCH bytes
* for the longest run, plus one for the unrolled loop.
*/
if (s->lookahead <= MAX_MATCH) {
fill_window(s);
if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
return need_more;
}
if (s->lookahead == 0) break; /* flush the current block */
}
/* See how many times the previous byte repeats */
s->match_length = 0;
if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
scan = s->window + s->strstart - 1;
prev = *scan;
if (prev == *++scan && prev == *++scan && prev == *++scan) {
strend = s->window + s->strstart + MAX_MATCH;
do {
} while (prev == *++scan && prev == *++scan &&
prev == *++scan && prev == *++scan &&
prev == *++scan && prev == *++scan &&
prev == *++scan && prev == *++scan &&
scan < strend);
s->match_length = MAX_MATCH - (uInt)(strend - scan);
if (s->match_length > s->lookahead)
s->match_length = s->lookahead;
}
Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
}
/* Emit match if have run of MIN_MATCH or longer, else emit literal */
if (s->match_length >= MIN_MATCH) {
check_match(s, s->strstart, s->strstart - 1, s->match_length);
_tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
s->lookahead -= s->match_length;
s->strstart += s->match_length;
s->match_length = 0;
} else {
/* No match, output a literal byte */
Tracevv((stderr,"%c", s->window[s->strstart]));
_tr_tally_lit (s, s->window[s->strstart], bflush);
s->lookahead--;
s->strstart++;
}
if (bflush) FLUSH_BLOCK(s, 0);
}
s->insert = 0;
if (flush == Z_FINISH) {
FLUSH_BLOCK(s, 1);
return finish_done;
}
if (s->last_lit)
FLUSH_BLOCK(s, 0);
return block_done;
}
/* ===========================================================================
* For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
* (It will be regenerated if this run of deflate switches away from Huffman.)
*/
static block_state deflate_huff( deflate_state *s, int flush )
{
int bflush; /* set if current block must be flushed */
for (;;) {
/* Make sure that we have a literal to write. */
if (s->lookahead == 0) {
fill_window(s);
if (s->lookahead == 0) {
if (flush == Z_NO_FLUSH)
return need_more;
break; /* flush the current block */
}
}
/* Output a literal byte */
s->match_length = 0;
Tracevv((stderr,"%c", s->window[s->strstart]));
_tr_tally_lit (s, s->window[s->strstart], bflush);
s->lookahead--;
s->strstart++;
if (bflush) FLUSH_BLOCK(s, 0);
}
s->insert = 0;
if (flush == Z_FINISH) {
FLUSH_BLOCK(s, 1);
return finish_done;
}
if (s->last_lit)
FLUSH_BLOCK(s, 0);
return block_done;
}
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