/* deflate.c -- compress data using the deflation algorithm

* Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler

* For conditions of distribution and use, see copyright notice in zlib.h

*/

/*

* ALGORITHM

*

* The "deflation" process depends on being able to identify portions

* of the input text which are identical to earlier input (within a

* sliding window trailing behind the input currently being processed).

*

* The most straightforward technique turns out to be the fastest for

* most input files: try all possible matches and select the longest.

* The key feature of this algorithm is that insertions into the string

* dictionary are very simple and thus fast, and deletions are avoided

* completely. Insertions are performed at each input character, whereas

* string matches are performed only when the previous match ends. So it

* is preferable to spend more time in matches to allow very fast string

* insertions and avoid deletions. The matching algorithm for small

* strings is inspired from that of Rabin & Karp. A brute force approach

* is used to find longer strings when a small match has been found.

* A similar algorithm is used in comic (by Jan-Mark Wams) and freeze

* (by Leonid Broukhis).

* A previous version of this file used a more sophisticated algorithm

* (by Fiala and Greene) which is guaranteed to run in linear amortized

* time, but has a larger average cost, uses more memory and is patented.

* However the F&G algorithm may be faster for some highly redundant

* files if the parameter max_chain_length (described below) is too large.

*

* ACKNOWLEDGEMENTS

*

* The idea of lazy evaluation of matches is due to Jan-Mark Wams, and

* I found it in 'freeze' written by Leonid Broukhis.

* Thanks to many people for bug reports and testing.

*

* REFERENCES

*

* Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".

* Available in http://tools.ietf.org/html/rfc1951

*

* A description of the Rabin and Karp algorithm is given in the book

* "Algorithms" by R. Sedgewick, Addison-Wesley, p252.

*

* Fiala,E.R., and Greene,D.H.

* Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595

*

*/

/* @(#) $Id$ */

#include "deflate.h"

const char deflate_copyright[] =

" deflate 1.2.8 Copyright 1995-2013 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) OF((deflate_state *s, int flush));

/* Compression function. Returns the block state after the call. */

local void fill_window OF((deflate_state *s));

local block_state deflate_stored OF((deflate_state *s, int flush));

local block_state deflate_fast OF((deflate_state *s, int flush));

#ifndef FASTEST

local block_state deflate_slow OF((deflate_state *s, int flush));

#endif

local block_state deflate_rle OF((deflate_state *s, int flush));

local block_state deflate_huff OF((deflate_state *s, int flush));

local void lm_init OF((deflate_state *s));

local void putShortMSB OF((deflate_state *s, uInt b));

local void flush_pending OF((z_streamp strm));

local int read_buf OF((z_streamp strm, Bytef *buf, unsigned size));

#ifdef ASMV

void match_init OF((void)); /* asm code initialization */

uInt longest_match OF((deflate_state *s, IPos cur_match));

#else

local uInt longest_match OF((deflate_state *s, IPos cur_match));

#endif

#ifdef DEBUG

local void check_match OF((deflate_state *s, IPos start, IPos match,

int length));

#endif

/* ===========================================================================

* 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;

#ifdef FASTEST

local const config configuration_table[2] = {

/* 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 */

#else

local 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 */

#endif

/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4

* For deflate_fast() (levels <= 3) good is ignored and lazy has a different

* meaning.

*/

#define EQUAL 0

/* result of memcmp for equal strings */

#ifndef NO_DUMMY_DECL

struct static_tree_desc_s {int dummy;}; /* for buggy compilers */

#endif

/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */

#define RANK(f) (((f) << 1) - ((f) > 4 ? 9 : 0))

/* ===========================================================================

* Update a hash value with the given input byte

* IN assertion: all calls to to UPDATE_HASH are made with consecutive

* input characters, so that a running hash key can be computed from the

* previous key instead of complete recalculation each time.

*/

#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)

/* ===========================================================================

* Insert string str in the dictionary and set match_head to the previous head

* of the hash chain (the most recent string with same hash key). Return

* the previous length of the hash chain.

* 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 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));

/* ========================================================================= */

int ZEXPORT deflateInit_(strm, level, version, stream_size)

z_streamp strm;

int level;

const char *version;

int stream_size;

{

return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,

Z_DEFAULT_STRATEGY, version, stream_size);

/* To do: ignore strm->next_in if we use it as window */

}

/* ========================================================================= */

int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,

version, stream_size)

z_streamp strm;

int level;

int method;

int windowBits;

int memLevel;

int strategy;

const char *version;

int stream_size;

{

deflate_state *s;

int wrap = 1;

static const char my_version[] = ZLIB_VERSION;

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.

*/

if (version == Z_NULL || version[0] != my_version[0] ||

stream_size != sizeof(z_stream)) {

return Z_VERSION_ERROR;

}

if (strm == Z_NULL) return Z_STREAM_ERROR;

strm->msg = Z_NULL;

if (strm->zalloc == (alloc_func)0) {

#ifdef Z_SOLO

return Z_STREAM_ERROR;

#else

strm->zalloc = zcalloc;

strm->opaque = (voidpf)0;

#endif

}

if (strm->zfree == (free_func)0)

#ifdef Z_SOLO

return Z_STREAM_ERROR;

#else

strm->zfree = zcfree;

#endif

#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) {

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->wrap = wrap;

s->gzhead = Z_NULL;

s->w_bits = windowBits;

s->w_size = 1 << s->w_bits;

s->w_mask = s->w_size - 1;

s->hash_bits = memLevel + 7;

s->hash_size = 1 << s->hash_bits;

s->hash_mask = s->hash_size - 1;

s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);

s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));

s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));

s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));

s->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);

}

/* ========================================================================= */

int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)

z_streamp strm;

const Bytef *dictionary;

uInt dictLength;

{

deflate_state *s;

uInt str, n;

int wrap;

unsigned avail;

z_const unsigned char *next;

if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)

return Z_STREAM_ERROR;

s = strm->state;

wrap = s->wrap;

if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)

return Z_STREAM_ERROR;

/* when using zlib wrappers, compute Adler-32 for provided dictionary */

if (wrap == 1)

strm->adler = adler32(strm->adler, dictionary, dictLength);

s->wrap = 0; /* avoid computing Adler-32 in read_buf */

/* if dictionary would fill window, just replace the history */

if (dictLength >= s->w_size) {

if (wrap == 0) { /* already empty otherwise */

CLEAR_HASH(s);

s->strstart = 0;

s->block_start = 0L;

s->insert = 0;

}

dictionary += dictLength - s->w_size; /* use the tail */

dictLength = s->w_size;

}

/* insert dictionary into window and hash */

avail = strm->avail_in;

next = strm->next_in;

strm->avail_in = dictLength;

strm->next_in = (z_const Bytef *)dictionary;

fill_window(s);

while (s->lookahead >= MIN_MATCH) {

str = s->strstart;

n = s->lookahead - (MIN_MATCH-1);

do {

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++;

} while (--n);

s->strstart = str;

s->lookahead = MIN_MATCH-1;

fill_window(s);

}

s->strstart += s->lookahead;

s->block_start = (long)s->strstart;

s->insert = s->lookahead;

s->lookahead = 0;

s->match_length = s->prev_length = MIN_MATCH-1;

s->match_available = 0;

strm->next_in = next;

strm->avail_in = avail;

s->wrap = wrap;

return Z_OK;

}

/* ========================================================================= */

int ZEXPORT deflateResetKeep (strm)

z_streamp strm;

{

deflate_state *s;

if (strm == Z_NULL || strm->state == Z_NULL ||

strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) {

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 = 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;

}

/* ========================================================================= */

int ZEXPORT deflateReset (strm)

z_streamp strm;

{

int ret;

ret = deflateResetKeep(strm);

if (ret == Z_OK)

lm_init(strm->state);

return ret;

}

/* ========================================================================= */

int ZEXPORT deflateSetHeader (strm, head)

z_streamp strm;

gz_headerp head;

{

if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;

if (strm->state->wrap != 2) return Z_STREAM_ERROR;

strm->state->gzhead = head;

return Z_OK;

}

/* ========================================================================= */

int ZEXPORT deflatePending (strm, pending, bits)

unsigned *pending;

int *bits;

z_streamp strm;

{

if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;

if (pending != Z_NULL)

*pending = strm->state->pending;

if (bits != Z_NULL)

*bits = strm->state->bi_valid;

return Z_OK;

}

/* ========================================================================= */

int ZEXPORT deflatePrime (strm, bits, value)

z_streamp strm;

int bits;

int value;

{

deflate_state *s;

int put;

if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;

s = strm->state;

if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))

return Z_BUF_ERROR;

do {

put = Buf_size - s->bi_valid;

if (put > bits)

put = bits;

s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);

s->bi_valid += put;

_tr_flush_bits(s);

value >>= put;

bits -= put;

} while (bits);

return Z_OK;

}

/* ========================================================================= */

int ZEXPORT deflateParams(strm, level, strategy)

z_streamp strm;

int level;

int strategy;

{

deflate_state *s;

compress_func func;

int err = Z_OK;

if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;

s = strm->state;

#ifdef FASTEST

if (level != 0) level = 1;

#else

if (level == Z_DEFAULT_COMPRESSION) level = 6;

#endif

if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {

return Z_STREAM_ERROR;

}

func = configuration_table[s->level].func;

if ((strategy != s->strategy || func != configuration_table[level].func) &&

strm->total_in != 0) {

/* Flush the last buffer: */

err = deflate(strm, Z_BLOCK);

if (err == Z_BUF_ERROR && s->pending == 0)

err = Z_OK;

}

if (s->level != level) {

s->level = level;

s->max_lazy_match = configuration_table[level].max_lazy;

s->good_match = configuration_table[level].good_length;

s->nice_match = configuration_table[level].nice_length;

s->max_chain_length = configuration_table[level].max_chain;

}

s->strategy = strategy;

return err;

}

/* ========================================================================= */

int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)

z_streamp strm;

int good_length;

int max_lazy;

int nice_length;

int max_chain;

{

deflate_state *s;

if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;

s = strm->state;

s->good_match = good_length;

s->max_lazy_match = max_lazy;

s->nice_match = nice_length;

s->max_chain_length = max_chain;

return Z_OK;

}

/* =========================================================================

* For the default windowBits of 15 and memLevel of 8, this function returns

* a close to exact, as well as small, upper bound on the compressed size.

* They are coded as constants here for a reason--if the #define's are

* changed, then this function needs to be changed as well. The return

* value for 15 and 8 only works for those exact settings.

*

* For any setting other than those defaults for windowBits and memLevel,

* the value returned is a conservative worst case for the maximum expansion

* resulting from using fixed blocks instead of stored blocks, which deflate

* can emit on compressed data for some combinations of the parameters.

*

* This function could be more sophisticated to provide closer upper bounds for

* every combination of windowBits and memLevel. But even the conservative

* upper bound of about 14% expansion does not seem onerous for output buffer

* allocation.

*/

uLong ZEXPORT deflateBound(strm, sourceLen)

z_streamp strm;

uLong sourceLen;

{

deflate_state *s;

uLong complen, wraplen;

Bytef *str;

/* conservative upper bound for compressed data */

complen = sourceLen +

((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;

/* if can't get parameters, return conservative bound plus zlib wrapper */

if (strm == Z_NULL || strm->state == Z_NULL)

return complen + 6;

/* compute wrapper length */

s = strm->state;

switch (s->wrap) {

case 0: /* raw deflate */

wraplen = 0;

break;

case 1: /* zlib wrapper */

wraplen = 6 + (s->strstart ? 4 : 0);

break;

case 2: /* gzip wrapper */

wraplen = 18;

if (s->gzhead != Z_NULL) { /* user-supplied gzip header */

if (s->gzhead->extra != Z_NULL)

wraplen += 2 + s->gzhead->extra_len;

str = s->gzhead->name;

if (str != Z_NULL)

do {

wraplen++;

} while (*str++);

str = s->gzhead->comment;

if (str != Z_NULL)

do {

wraplen++;

} while (*str++);

if (s->gzhead->hcrc)

wraplen += 2;

}

break;

default: /* for compiler happiness */

wraplen = 6;

}

/* if not default parameters, return conservative bound */

if (s->w_bits != 15 || s->hash_bits != 8 + 7)

return complen + wraplen;

/* default settings: return tight bound for that case */

return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +

(sourceLen >> 25) + 13 - 6 + wraplen;

}

/* =========================================================================

* Put a short in the pending buffer. The 16-bit value is put in MSB order.

* IN assertion: the stream state is correct and there is enough room in

* pending_buf.

*/

local void putShortMSB (s, b)

deflate_state *s;

uInt b;

{

put_byte(s, (Byte)(b >> 8));

put_byte(s, (Byte)(b & 0xff));

}

/* =========================================================================

* Flush as much pending output as possible. All deflate() 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()).

*/

local void flush_pending(strm)

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;

}

}

/* ========================================================================= */

int ZEXPORT deflate (strm, flush)

z_streamp strm;

int flush;

{

int old_flush; /* value of flush param for previous deflate call */

deflate_state *s;

if (strm == Z_NULL || strm->state == Z_NULL ||

flush > Z_BLOCK || flush < 0) {

return Z_STREAM_ERROR;

}

s = strm->state;

if (strm->next_out == Z_NULL ||

(strm->next_in == Z_NULL && strm->avail_in != 0) ||

(s->status == FINISH_STATE && flush != Z_FINISH)) {

ERR_RETURN(strm, Z_STREAM_ERROR);

}

if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);

s->strm = strm; /* just in case */

old_flush = s->last_flush;

s->last_flush = flush;

/* Write the header */

if (s->status == INIT_STATE) {

#ifdef GZIP

if (s->wrap == 2) {

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;

}

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;

}

}

else

#endif

{

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);

s->status = BUSY_STATE;

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);

}

}

#ifdef GZIP

if (s->status == EXTRA_STATE) {

if (s->gzhead->extra != Z_NULL) {

uInt beg = s->pending; /* start of bytes to update crc */

while (s->gzindex < (s->gzhead->extra_len & 0xffff)) {

if (s->pending == s->pending_buf_size) {

if (s->gzhead->hcrc && s->pending > beg)

strm->adler = crc32(strm->adler, s->pending_buf + beg,

s->pending - beg);

flush_pending(strm);

beg = s->pending;

if (s->pending == s->pending_buf_size)

break;

}

put_byte(s, s->gzhead->extra[s->gzindex]);

s->gzindex++;

}

if (s->gzhead->hcrc && s->pending > beg)

strm->adler = crc32(strm->adler, s->pending_buf + beg,

s->pending - beg);

if (s->gzindex == s->gzhead->extra_len) {

s->gzindex = 0;

s->status = NAME_STATE;

}

}

else

s->status = NAME_STATE;

}

if (s->status == NAME_STATE) {

if (s->gzhead->name != Z_NULL) {

uInt beg = s->pending; /* start of bytes to update crc */

int val;

do {

if (s->pending == s->pending_buf_size) {

if (s->gzhead->hcrc && s->pending > beg)

strm->adler = crc32(strm->adler, s->pending_buf + beg,

s->pending - beg);

flush_pending(strm);

beg = s->pending;

if (s->pending == s->pending_buf_size) {

val = 1;

break;

}

}

val = s->gzhead->name[s->gzindex++];

put_byte(s, val);

} while (val != 0);

if (s->gzhead->hcrc && s->pending > beg)

strm->adler = crc32(strm->adler, s->pending_buf + beg,

s->pending - beg);

if (val == 0) {

s->gzindex = 0;

s->status = COMMENT_STATE;

}

}

else

s->status = COMMENT_STATE;

}

if (s->status == COMMENT_STATE) {

if (s->gzhead->comment != Z_NULL) {

uInt beg = s->pending; /* start of bytes to update crc */

int val;

do {

if (s->pending == s->pending_buf_size) {

if (s->gzhead->hcrc && s->pending > beg)

strm->adler = crc32(strm->adler, s->pending_buf + beg,

s->pending - beg);

flush_pending(strm);

beg = s->pending;

if (s->pending == s->pending_buf_size) {

val = 1;

break;

}

}

val = s->gzhead->comment[s->gzindex++];

put_byte(s, val);

} while (val != 0);

if (s->gzhead->hcrc && s->pending > beg)

strm->adler = crc32(strm->adler, s->pending_buf + beg,

s->pending - beg);

if (val == 0)

s->status = HCRC_STATE;

}

else

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 + 2 <= s->pending_buf_size) {

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;

}

}

else

s->status = BUSY_STATE;

}

#endif

/* 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);

}

/* 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->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;

}

}

}

Assert(strm->avail_out > 0, "bug2");

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 ZEXPORT deflateEnd (strm)

z_streamp strm;

{

int status;

if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;

status = strm->state->status;

if (status != INIT_STATE &&

status != EXTRA_STATE &&

status != NAME_STATE &&

status != COMMENT_STATE &&

status != HCRC_STATE &&

status != BUSY_STATE &&

status != FINISH_STATE) {

return Z_STREAM_ERROR;

}

/* 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);