FCL/sf/os/ossrv: comparison compressionlibs/ziplib/src/zlib/deflate.cpp

equal deleted inserted replaced

--1:000000000000
+:e4d67989cc36
+/* Portions Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+*/
+/* deflate.cpp -- compress data using the deflation algorithm
+* Copyright (C) 1995-2005 Jean-loup Gailly.
+* For conditions of distribution and use, see copyright notice in zlib.h
+*/
+/*
+*  ALGORITHM
+*
+*      The "deflation" process depends on being able to identify portions
+*      of the input text which are identical to earlier input (within a
+*      sliding window trailing behind the input currently being processed).
+*
+*      The most straightforward technique turns out to be the fastest for
+*      most input files: try all possible matches and select the longest.
+*      The key feature of this algorithm is that insertions into the string
+*      dictionary are very simple and thus fast, and deletions are avoided
+*      completely. Insertions are performed at each input character, whereas
+*      string matches are performed only when the previous match ends. So it
+*      is preferable to spend more time in matches to allow very fast string
+*      insertions and avoid deletions. The matching algorithm for small
+*      strings is inspired from that of Rabin & Karp. A brute force approach
+*      is used to find longer strings when a small match has been found.
+*      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
+*      (by Leonid Broukhis).
+*         A previous version of this file used a more sophisticated algorithm
+*      (by Fiala and Greene) which is guaranteed to run in linear amortized
+*      time, but has a larger average cost, uses more memory and is patented.
+*      However the F&G algorithm may be faster for some highly redundant
+*      files if the parameter max_chain_length (described below) is too large.
+*
+*  ACKNOWLEDGEMENTS
+*
+*      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
+*      I found it in 'freeze' written by Leonid Broukhis.
+*      Thanks to many people for bug reports and testing.
+*
+*  REFERENCES
+*
+*      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
+*      Available in http://www.ietf.org/rfc/rfc1951.txt
+*
+*      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 1.2.3 Copyright 1995-2005 Jean-loup Gailly ";
+/*
+If you use the zlib library in a product, an acknowledgment is welcome
+in the documentation of your product. If for some reason you cannot
+include such an acknowledgment, I would appreciate that you keep this
+copyright string in the executable of your product.
+*/
+/* ===========================================================================
+*  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 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));
+#ifndef FASTEST
+#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
+#endif
+local uInt longest_match_fast OF((deflate_state *s, IPos cur_match));
+#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 */
+#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
+/* Minimum amount of lookahead, except at the end of the input file.
+* See deflate.c for comments about the MIN_MATCH+1.
+*/
+/* Values for max_lazy_match, good_match and max_chain_length, depending on
+* the desired pack level (0..9). The values given below have been tuned to
+* exclude worst case performance for pathological files. Better values may be
+* found for specific files.
+*/
+typedef struct config_s {
+ush good_length; /* reduce lazy search above this match length */
+ush max_lazy;    /* do not perform lazy search above this match length */
+ush nice_length; /* quit search above this match length */
+ush max_chain;
+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
+/* ===========================================================================
+* 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));
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int  deflateInit__r( z_streamp strm,int  level,const char * version,int  stream_size)
+#else
+int ZEXPORT deflateInit_(strm, level, version, stream_size)
+z_streamp strm;
+int level;
+const char *version;
+int stream_size;
+#endif //__SYMBIAN32__
+{
+return deflateInit2__r(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 */
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int  deflateInit2__r(z_streamp strm, int level,int method,int windowBits,int memLevel,int strategy,
+const char * version,int stream_size)
+#else
+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;
+#endif //__SYMBIAN32__
+{
+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) {
+strm->zalloc = zcalloc;
+strm->opaque = (voidpf)0;
+}
+if (strm->zfree == (free_func)0) strm->zfree = zcfree;
+#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->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 = (char*)ERR_MSG(Z_MEM_ERROR);
+deflateEnd_r (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_r (strm);
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int  deflateSetDictionary_r (z_streamp strm, const Bytef *  dictionary,uInt   dictLength)
+#else
+int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
+z_streamp strm;
+const Bytef *dictionary;
+uInt  dictLength;
+#endif //__SYMBIAN32__
+{
+deflate_state *s;
+uInt length = dictLength;
+uInt n;
+IPos hash_head = 0;
+	// Line to stop compiler warning about unused mandatory global variable 'deflate_copyright'
+	char dontCare = deflate_copyright[0]; dontCare = dontCare;
+if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL ||
+strm->state->wrap == 2 ||
+(strm->state->wrap == 1 && strm->state->status != INIT_STATE))
+return Z_STREAM_ERROR;
+s = strm->state;
+if (s->wrap)
+strm->adler = adler32_r(strm->adler, dictionary, dictLength);
+if (length < MIN_MATCH) return Z_OK;
+if (length > MAX_DIST(s)) {
+length = MAX_DIST(s);
+dictionary += dictLength - length; /* use the tail of the dictionary */
+}
+zmemcpy(s->window, dictionary, length);
+s->strstart = length;
+s->block_start = (long)length;
+/* Insert all strings in the hash table (except for the last two bytes).
+* s->lookahead stays null, so s->ins_h will be recomputed at the next
+* call of fill_window.
+*/
+s->ins_h = s->window[0];
+UPDATE_HASH(s, s->ins_h, s->window[1]);
+for (n = 0; n <= length - MIN_MATCH; n++) {
+INSERT_STRING(s, n, hash_head);
+}
+if (hash_head) hash_head = 0;  /* to make compiler happy */
+return Z_OK;
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int  deflateReset_r (z_streamp strm)
+#else
+int ZEXPORT deflateReset (strm)
+z_streamp strm;
+#endif //__SYMBIAN32__
+{
+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_r(0L, Z_NULL, 0) :
+#endif
+adler32_r(0L, Z_NULL, 0);
+s->last_flush = Z_NO_FLUSH;
+_tr_init(s);
+lm_init(s);
+return Z_OK;
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int deflateSetHeader_r (z_streamp strm, gz_headerp  head)
+#else
+int ZEXPORT deflateSetHeader (strm, head)
+z_streamp strm;
+gz_headerp head;
+#endif //__SYMBIAN32__
+{
+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;
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int  deflatePrime_r (z_streamp strm,int  bits,int  value)
+#else
+int ZEXPORT deflatePrime (strm, bits, value)
+z_streamp strm;
+int bits;
+int value;
+#endif //__SYMBIAN32__
+{
+if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+strm->state->bi_valid = bits;
+strm->state->bi_buf = (ush)(value & ((1 << bits) - 1));
+return Z_OK;
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int deflateParams_r (z_streamp strm,int  level,int  strategy)
+#else
+int ZEXPORT deflateParams(strm, level, strategy)
+z_streamp strm;
+int level;
+int strategy;
+#endif //__SYMBIAN32__
+{
+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 (func != configuration_table[level].func && strm->total_in != 0) {
+/* Flush the last buffer: */
+err = deflate_r(strm, Z_PARTIAL_FLUSH);
+}
+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;
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int  deflateTune_r(z_streamp strm, int good_length, int max_lazy, int nice_length, int max_chain)
+#else
+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;
+#endif //__SYMBIAN32__
+{
+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, as well as wrap.
+* But even the conservative upper bound of about 14% expansion does not
+* seem onerous for output buffer allocation.
+*/
+#ifdef __SYMBIAN32__
+EXPORT_C  uLong deflateBound_r(z_streamp strm,uLong  sourceLen)
+#else
+uLong ZEXPORT deflateBound(strm, sourceLen)
+z_streamp strm;
+uLong sourceLen;
+#endif //__SYMBIAN32__
+{
+deflate_state *s;
+uLong destLen;
+/* conservative upper bound */
+destLen = sourceLen +
+((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 11;
+/* if can't get parameters, return conservative bound */
+if (strm == Z_NULL || strm->state == Z_NULL)
+return destLen;
+/* if not default parameters, return conservative bound */
+s = strm->state;
+if (s->w_bits != 15 || s->hash_bits != 8 + 7)
+return destLen;
+/* default settings: return tight bound for that case */
+return compressBound_r(sourceLen);
+}
+/* =========================================================================
+* 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.
+*/
+#ifdef __SYMBIAN32__
+local void putShortMSB (deflate_state * s, uInt  b)
+#else
+local void putShortMSB (s, b)
+deflate_state *s;
+uInt b;
+#endif //__SYMBIAN32__
+{
+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()).
+*/
+#ifdef __SYMBIAN32__
+local void flush_pending(z_streamp strm)
+#else
+local void flush_pending(strm)
+z_streamp strm;
+#endif //__SYMBIAN32__
+{
+unsigned len = strm->state->pending;
+if (len > strm->avail_out) len = strm->avail_out;
+if (len == 0) return;
+zmemcpy(strm->next_out, strm->state->pending_out, len);
+strm->next_out  += len;
+strm->state->pending_out  += len;
+strm->total_out += len;
+strm->avail_out  -= len;
+strm->state->pending -= len;
+if (strm->state->pending == 0) {
+strm->state->pending_out = strm->state->pending_buf;
+}
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int  deflate_r (z_streamp strm,int  flush)
+#else
+int ZEXPORT deflate (strm, flush)
+z_streamp strm;
+int flush;
+#endif //__SYMBIAN32__
+{
+int old_flush; /* value of flush param for previous deflate call */
+deflate_state *s;
+if (strm == Z_NULL || strm->state == Z_NULL ||
+flush > Z_FINISH || 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_r(0L, Z_NULL, 0);
+put_byte(s, 31);
+put_byte(s, 139);
+put_byte(s, 8);
+if (s->gzhead == 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 != 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_r(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_r(0L, Z_NULL, 0);
+}
+}
+#ifdef GZIP
+if (s->status == EXTRA_STATE) {
+if (s->gzhead->extra != 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_r(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_r(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 != 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_r(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_r(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 != 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_r(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_r(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_r(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 && flush <= 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 = (*(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 { /* 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 */
+}
+}
+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;
+}
+/* ========================================================================= */
+#ifdef __SYMBIAN32__
+EXPORT_C int   deflateEnd_r (z_streamp strm)
+#else
+int ZEXPORT deflateEnd (strm)
+z_streamp strm;
+#endif //__SYMBIAN32__
+{
+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);
+TRY_FREE(strm, strm->state->window);
+ZFREE(strm, strm->state);
+strm->state = Z_NULL;
+return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
+}
+/* =========================================================================
+* Copy the source state to the destination state.
+* To simplify the source, this is not supported for 16-bit MSDOS (which
+* doesn't have enough memory anyway to duplicate compression states).
+*/
+#ifdef __SYMBIAN32__
+EXPORT_C int deflateCopy_r (z_streamp dest, z_streamp source)
+#else
+int ZEXPORT deflateCopy (dest, source)
+z_streamp dest;
+z_streamp source;
+#endif //__SYMBIAN32__
+{
+#ifdef MAXSEG_64K
+return Z_STREAM_ERROR;
+#else
+deflate_state *ds;
+deflate_state *ss;
+ushf *overlay;
+if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
+return Z_STREAM_ERROR;
+}
+ss = source->state;
+zmemcpy(dest, source, sizeof(z_stream));
+ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
+if (ds == Z_NULL) return Z_MEM_ERROR;
+dest->state = (struct internal_state FAR *) ds;
+zmemcpy(ds, ss, sizeof(deflate_state));
+ds->strm = dest;
+ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
+ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
+ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
+overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
+ds->pending_buf = (uchf *) overlay;
+if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
+ds->pending_buf == Z_NULL) {
+deflateEnd_r (dest);
+return Z_MEM_ERROR;
+}
+/* following zmemcpy do not work for 16-bit MSDOS */
+zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
+zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
+zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
+zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
+ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
+ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
+ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
+ds->l_desc.dyn_tree = ds->dyn_ltree;
+ds->d_desc.dyn_tree = ds->dyn_dtree;
+ds->bl_desc.dyn_tree = ds->bl_tree;
+return Z_OK;
+#endif /* MAXSEG_64K */
+}
+/* ===========================================================================
+* 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()).
+*/
+#ifdef __SYMBIAN32__
+local int read_buf(z_streamp strm,Bytef *  buf,unsigned  size)
+#else
+local int read_buf(strm, buf, size)
+z_streamp strm;
+Bytef *buf;
+unsigned size;
+#endif //__SYMBIAN32__
+{
+unsigned len = strm->avail_in;
+if (len > size) len = size;
+if (len == 0) return 0;
+strm->avail_in  -= len;
+if (strm->state->wrap == 1) {
+strm->adler = adler32_r(strm->adler, strm->next_in, len);
+}
+#ifdef GZIP
+else if (strm->state->wrap == 2) {
+strm->adler = crc32_r(strm->adler, strm->next_in, len);
+}
+#endif
+zmemcpy(buf, strm->next_in, len);
+strm->next_in  += len;
+strm->total_in += len;
+return (int)len;
+}
+/* ===========================================================================
+* Initialize the "longest match" routines for a new zlib stream
+*/
+#ifdef __SYMBIAN32__
+local void lm_init (deflate_state * s)
+#else
+local void lm_init (s)
+deflate_state *s;
+#endif //__SYMBIAN32__
+{
+s->window_size = (ulg)2L*s->w_size;
+CLEAR_HASH(s);
+/* Set the default configuration parameters:
+*/
+s->max_lazy_match   = configuration_table[s->level].max_lazy;
+s->good_match       = configuration_table[s->level].good_length;
+s->nice_match       = configuration_table[s->level].nice_length;
+s->max_chain_length = configuration_table[s->level].max_chain;
+s->strstart = 0;
+s->block_start = 0L;
+s->lookahead = 0;
+s->match_length = s->prev_length = MIN_MATCH-1;
+s->match_available = 0;
+s->ins_h = 0;
+#ifndef FASTEST
+#ifdef ASMV
+match_init(); /* initialize the asm code */
+#endif
+#endif
+}
+#ifndef FASTEST
+/* ===========================================================================
+* 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.
+*/
+#ifndef ASMV
+/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
+* match.S. The code will be functionally equivalent.
+*/
+#ifdef __SYMBIAN32__
+local uInt longest_match(deflate_state * s,IPos  cur_match)
+#else
+local uInt longest_match(s, cur_match)
+deflate_state *s;
+IPos cur_match;                             /* current match */
+#endif //__SYMBIAN32__
+{
+unsigned chain_length = s->max_chain_length;/* max hash chain length */
+register Bytef *scan = s->window + s->strstart; /* current string */
+register Bytef *match;                       /* matched string */
+register int len;                           /* length of current match */
+int best_len = s->prev_length;              /* best match length so far */
+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 = 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;
+}
+#endif /* ASMV */
+#endif /* FASTEST */
+/* ---------------------------------------------------------------------------
+* Optimized version for level == 1 or strategy == Z_RLE only
+*/
+#ifdef __SYMBIAN32__
+local uInt longest_match_fast(deflate_state * s,IPos cur_match)
+#else
+local uInt longest_match_fast(s, cur_match)
+deflate_state *s;
+IPos cur_match;                             /* current match */
+#endif //__SYMBIAN32__
+{
+register Bytef *scan = s->window + s->strstart; /* current string */
+register Bytef *match;                       /* matched string */
+register int len;                           /* length of current match */
+register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+/* 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");
+Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+Assert(cur_match < s->strstart, "no future");
+match = s->window + cur_match;
+/* Return failure if the match length is less than 2:
+*/
+if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
+/* 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 += 2;
+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);
+if (len < MIN_MATCH) return MIN_MATCH - 1;
+s->match_start = cur_match;
+return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
+}
+#ifdef DEBUG
+/* ===========================================================================
+* Check that the match at match_start is indeed a match.
+*/
+#ifdef __SYMBIAN32__
+local void check_match( deflate_state * s,IPos  start, match,int length)
+#else
+local void check_match(s, start, match, length)
+deflate_state *s;
+IPos start, match;
+int length;
+#endif //__SYMBIAN32__
+{
+/* check that the match is indeed a match */
+if (zmemcmp(s->window + match,
+s->window + start, length) != EQUAL) {
+fprintf(stderr, " start %u, match %u, length %d\n",
+start, match, length);
+do {
+fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
+} while (--length != 0);
+z_error("invalid match");
+}
+if (z_verbose > 1) {
+fprintf(stderr,"\\[%d,%d]", start-match, length);
+do { putc(s->window[start++], stderr); } while (--length != 0);
+}
+}
+#else
+#  define check_match(s, start, match, length)
+#endif /* DEBUG */
+/* ===========================================================================
+* 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).
+*/
+#ifdef __SYMBIAN32__
+local void fill_window(   deflate_state * s)
+#else
+local void fill_window(s)
+deflate_state *s;
+#endif //__SYMBIAN32__
+{
+register unsigned n, m;
+register Posf *p;
+unsigned more;    /* Amount of free space at the end of the window. */
+uInt wsize = s->w_size;
+do {
+more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
+/* Deal with !@#$% 64K limit: */
+if (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);
+s->match_start -= wsize;
+s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
+s->block_start -= (long) wsize;
+/* Slide the hash table (could be avoided with 32 bit values
+at the expense of memory usage). We slide even when level == 0
+to keep the hash table consistent if we switch back to level > 0
+later. (Using level 0 permanently is not an optimal usage of
+zlib, so we don't care about this pathological case.)
+*/
+/* %%% avoid this when Z_RLE */
+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
+more += wsize;
+}
+if (s->strm->avail_in == 0) return;
+/* If there was no sliding:
+*    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
+*    more == window_size - lookahead - strstart
+* => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
+* => more >= window_size - 2*WSIZE + 2
+* In the BIG_MEM or MMAP case (not yet supported),
+*   window_size == input_size + MIN_LOOKAHEAD  &&
+*   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
+* Otherwise, window_size == 2*WSIZE so more >= 2.
+* If there was sliding, more >= WSIZE. So in all cases, more >= 2.
+*/
+Assert(more >= 2, "more < 2");
+n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
+s->lookahead += n;
+/* Initialize the hash value now that we have some input: */
+if (s->lookahead >= MIN_MATCH) {
+s->ins_h = s->window[s->strstart];
+UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
+#if MIN_MATCH != 3
+Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+}
+/* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
+* but this is not important since only literal bytes will be emitted.
+*/
+} while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
+}
+/* ===========================================================================
+* Flush the current block, with given end-of-file flag.
+* IN assertion: strstart is set to the end of the current match.
+*/
+#define FLUSH_BLOCK_ONLY(s, eof) { \
+_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), \
+(eof)); \
+s->block_start = s->strstart; \
+flush_pending(s->strm); \
+Tracev((stderr,"[FLUSH]")); \
+}
+/* Same but force premature exit if necessary. */
+#define FLUSH_BLOCK(s, eof) { \
+FLUSH_BLOCK_ONLY(s, eof); \
+if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
+}
+/* ===========================================================================
+* Copy without compression as much as possible from the input stream, return
+* the current block state.
+* This function does not insert new strings in the dictionary since
+* uncompressible data is probably not useful. This function is used
+* only for the level=0 compression option.
+* NOTE: this function should be optimized to avoid extra copying from
+* window to pending_buf.
+*/
+#ifdef __SYMBIAN32__
+local block_state deflate_stored(deflate_state * s,int flush)
+#else
+local block_state deflate_stored(s, flush)
+deflate_state *s;
+int flush;
+#endif //__SYMBIAN32__
+{
+/* Stored blocks are limited to 0xffff bytes, pending_buf is limited
+* to pending_buf_size, and each stored block has a 5 byte header:
+*/
+ulg max_block_size = 0xffff;
+ulg max_start;
+if (max_block_size > s->pending_buf_size - 5) {
+max_block_size = s->pending_buf_size - 5;
+}
+/* Copy as much as possible from input to output: */
+for (;;) {
+/* Fill the window as much as possible: */
+if (s->lookahead <= 1) {
+Assert(s->strstart < s->w_size+MAX_DIST(s) ||
+s->block_start >= (long)s->w_size, "slide too late");
+fill_window(s);
+if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
+if (s->lookahead == 0) break; /* flush the current block */
+}
+Assert(s->block_start >= 0L, "block gone");
+s->strstart += s->lookahead;
+s->lookahead = 0;
+/* Emit a stored block if pending_buf will be full: */
+max_start = s->block_start + max_block_size;
+if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
+/* strstart == 0 is possible when wraparound on 16-bit machine */
+s->lookahead = (uInt)(s->strstart - max_start);
+s->strstart = (uInt)max_start;
+FLUSH_BLOCK(s, 0);
+}
+/* Flush if we may have to slide, otherwise block_start may become
+* negative and the data will be gone:
+*/
+if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
+FLUSH_BLOCK(s, 0);
+}
+}
+FLUSH_BLOCK(s, flush == Z_FINISH);
+return flush == Z_FINISH ? finish_done : block_done;
+}
+/* ===========================================================================
+* 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.
+*/
+#ifdef __SYMBIAN32__
+local block_state deflate_fast(   deflate_state * s,int  flush)
+#else
+local block_state deflate_fast(s, flush)
+deflate_state *s;
+int flush;
+#endif //__SYMBIAN32__
+{
+IPos hash_head = NIL; /* 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:
+*/
+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).
+*/
+#ifdef FASTEST
+if ((s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) ||
+(s->strategy == Z_RLE && s->strstart - hash_head == 1)) {
+s->match_length = longest_match_fast (s, hash_head);
+}
+#else
+if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) {
+s->match_length = longest_match (s, hash_head);
+} else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) {
+s->match_length = longest_match_fast (s, hash_head);
+}
+#endif
+/* longest_match() or longest_match_fast() 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);
+}
+FLUSH_BLOCK(s, flush == Z_FINISH);
+return flush == Z_FINISH ? finish_done : block_done;
+}
+#ifndef FASTEST
+/* ===========================================================================
+* 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.
+*/
+#ifdef __SYMBIAN32__
+local block_state deflate_slow(  deflate_state * s,int  flush)
+#else
+local block_state deflate_slow(s, flush)
+deflate_state *s;
+int flush;
+#endif //__SYMBIAN32__
+{
+IPos hash_head = NIL;    /* head of hash chain */
+int bflush;              /* set if current block must be flushed */
+/* Process the input block. */
+for (;;) {
+/* Make sure that we always have enough lookahead, except
+* at the end of the input file. We need MAX_MATCH bytes
+* for the next match, plus MIN_MATCH bytes to insert the
+* string following the next match.
+*/
+if (s->lookahead < MIN_LOOKAHEAD) {
+fill_window(s);
+if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
+return 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:
+*/
+if (s->lookahead >= MIN_MATCH) {
+INSERT_STRING(s, s->strstart, hash_head);
+}
+/* Find the longest match, discarding those <= prev_length.
+*/
+s->prev_length = s->match_length, s->prev_match = s->match_start;
+s->match_length = MIN_MATCH-1;
+if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
+s->strstart - hash_head <= MAX_DIST(s)) {
+/* To simplify the code, we prevent matches with the string
+* of window index 0 (in particular we have to avoid a match
+* of the string with itself at the start of the input file).
+*/
+if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) {
+s->match_length = longest_match (s, hash_head);
+} else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) {
+s->match_length = longest_match_fast (s, hash_head);
+}
+/* longest_match() or longest_match_fast() 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;
+}
+FLUSH_BLOCK(s, flush == Z_FINISH);
+return flush == Z_FINISH ? finish_done : block_done;
+}
+#endif /* FASTEST */
+#if 0
+/* ===========================================================================
+* 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.)
+*/
+local block_state deflate_rle(s, flush)
+deflate_state *s;
+int flush;
+{
+int bflush;         /* set if current block must be flushed */
+uInt run;           /* length of run */
+uInt max;           /* maximum length of run */
+uInt prev;          /* byte at distance one to match */
+Bytef *scan;        /* scan for end 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 encodable run.
+*/
+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 */
+run = 0;
+if (s->strstart > 0) {      /* if there is a previous byte, that is */
+max = s->lookahead < MAX_MATCH ? s->lookahead : MAX_MATCH;
+scan = s->window + s->strstart - 1;
+prev = *scan++;
+do {
+if (*scan++ != prev)
+break;
+} while (++run < max);
+}
+/* Emit match if have run of MIN_MATCH or longer, else emit literal */
+if (run >= MIN_MATCH) {
+check_match(s, s->strstart, s->strstart - 1, run);
+_tr_tally_dist(s, 1, run - MIN_MATCH, bflush);
+s->lookahead -= run;
+s->strstart += run;
+} 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);
+}
+FLUSH_BLOCK(s, flush == Z_FINISH);
+return flush == Z_FINISH ? finish_done : block_done;
+}
+#endif