repos/blastem: zlib/deflate.c comparison

comparison zlib/deflate.c @ 2690:9ef72ee5c0b0

Update vendored zlib to 1.3.1

author	Michael Pavone <pavone@retrodev.com>
date	Sun, 15 Jun 2025 15:39:33 -0700
parents	00d788dac91a
children

comparison

equal deleted inserted replaced

-:bd6e33de0972
+:9ef72ee5c0b0
 /* deflate.c -- compress data using the deflation algorithm
-* Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+* Copyright (C) 1995-2024 Jean-loup Gailly and Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */
 /*
 *  ALGORITHM
 /* @(#) $Id$ */
 #include "deflate.h"
 const char deflate_copyright[] =
-" deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
+" deflate 1.3.1 Copyright 1995-2024 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));
+typedef block_state (*compress_func)(deflate_state *s, int flush);
 /* Compression function. Returns the block state after the call. */
-local int deflateStateCheck      OF((z_streamp strm));
+local block_state deflate_stored(deflate_state *s, int flush);
-local void slide_hash     OF((deflate_state *s));
+local block_state deflate_fast(deflate_state *s, int flush);
-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));
+local block_state deflate_slow(deflate_state *s, int flush);
 #endif
-local block_state deflate_rle    OF((deflate_state *s, int flush));
+local block_state deflate_rle(deflate_state *s, int flush);
-local block_state deflate_huff   OF((deflate_state *s, int flush));
+local block_state deflate_huff(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 unsigned read_buf   OF((z_streamp strm, Bytef *buf, unsigned size));
-#ifdef ASMV
-#  pragma message("Assembler code may have bugs -- use at your own risk")
-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 ZLIB_DEBUG
-local  void check_match OF((deflate_state *s, IPos start, IPos match,
-int length));
-#endif
 /* ===========================================================================
 * Local data
 */
 * 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)
+#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
 /* ===========================================================================
 * 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; \
+do { \
-zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
+s->head[s->hash_size - 1] = NIL; \
+zmemzero((Bytef *)s->head, \
+(unsigned)(s->hash_size - 1)*sizeof(*s->head)); \
+} while (0)
 /* ===========================================================================
 * 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.
 */
-local void slide_hash(s)
+#if defined(__has_feature)
-deflate_state *s;
+#  if __has_feature(memory_sanitizer)
-{
+__attribute__((no_sanitize("memory")))
+#  endif
+#endif
+local void slide_hash(deflate_state *s) {
 unsigned n, m;
 Posf *p;
 uInt wsize = s->w_size;
 n = s->hash_size;
 */
 } while (--n);
 #endif
 }
+/* ===========================================================================
+* 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()).
+*/
+local 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;
+}
+/* ===========================================================================
+* Fill the window when the lookahead becomes insufficient.
+* Updates strstart and lookahead.
+*
+* IN assertion: lookahead < MIN_LOOKAHEAD
+* OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
+*    At least one byte has been read, or avail_in == 0; reads are
+*    performed for at least two bytes (required for the zip translate_eol
+*    option -- not supported here).
+*/
+local void fill_window(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;
+if (s->insert > s->strstart)
+s->insert = s->strstart;
+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");
+}
 /* ========================================================================= */
-int ZEXPORT deflateInit_(strm, level, version, stream_size)
+int ZEXPORT deflateInit_(z_streamp strm, int level, const char *version,
-z_streamp strm;
+int stream_size) {
-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,
+int ZEXPORT deflateInit2_(z_streamp strm, int level, int method,
-version, stream_size)
+int windowBits, int memLevel, int strategy,
-z_streamp strm;
+const char *version, int stream_size) {
-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 (level == Z_DEFAULT_COMPRESSION) level = 6;
 #endif
 if (windowBits < 0) { /* suppress zlib wrapper */
 wrap = 0;
+if (windowBits < -15)
+return Z_STREAM_ERROR;
 windowBits = -windowBits;
 }
 #ifdef GZIP
 else if (windowBits > 15) {
 wrap = 2;       /* write gzip wrapper instead */
 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->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);
+/* We overlay pending_buf and sym_buf. This works since the average size
-s->pending_buf = (uchf *) overlay;
+* for length/distance pairs over any compressed block is assured to be 31
-s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
+* bits or less.
+*
+* Analysis: The longest fixed codes are a length code of 8 bits plus 5
+* extra bits, for lengths 131 to 257. The longest fixed distance codes are
+* 5 bits plus 13 extra bits, for distances 16385 to 32768. The longest
+* possible fixed-codes length/distance pair is then 31 bits total.
+*
+* sym_buf starts one-fourth of the way into pending_buf. So there are
+* three bytes in sym_buf for every four bytes in pending_buf. Each symbol
+* in sym_buf is three bytes -- two for the distance and one for the
+* literal/length. As each symbol is consumed, the pointer to the next
+* sym_buf value to read moves forward three bytes. From that symbol, up to
+* 31 bits are written to pending_buf. The closest the written pending_buf
+* bits gets to the next sym_buf symbol to read is just before the last
+* code is written. At that time, 31*(n - 2) bits have been written, just
+* after 24*(n - 2) bits have been consumed from sym_buf. sym_buf starts at
+* 8*n bits into pending_buf. (Note that the symbol buffer fills when n - 1
+* symbols are written.) The closest the writing gets to what is unread is
+* then n + 14 bits. Here n is lit_bufsize, which is 16384 by default, and
+* can range from 128 to 32768.
+*
+* Therefore, at a minimum, there are 142 bits of space between what is
+* written and what is read in the overlain buffers, so the symbols cannot
+* be overwritten by the compressed data. That space is actually 139 bits,
+* due to the three-bit fixed-code block header.
+*
+* That covers the case where either Z_FIXED is specified, forcing fixed
+* codes, or when the use of fixed codes is chosen, because that choice
+* results in a smaller compressed block than dynamic codes. That latter
+* condition then assures that the above analysis also covers all dynamic
+* blocks. A dynamic-code block will only be chosen to be emitted if it has
+* fewer bits than a fixed-code block would for the same set of symbols.
+* Therefore its average symbol length is assured to be less than 31. So
+* the compressed data for a dynamic block also cannot overwrite the
+* symbols from which it is being constructed.
+*/
+s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, LIT_BUFS);
+s->pending_buf_size = (ulg)s->lit_bufsize * 4;
 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);
+#ifdef LIT_MEM
-s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
+s->d_buf = (ushf *)(s->pending_buf + (s->lit_bufsize << 1));
+s->l_buf = s->pending_buf + (s->lit_bufsize << 2);
+s->sym_end = s->lit_bufsize - 1;
+#else
+s->sym_buf = s->pending_buf + s->lit_bufsize;
+s->sym_end = (s->lit_bufsize - 1) * 3;
+#endif
+/* We avoid equality with lit_bufsize*3 because of wraparound at 64K
+* on 16 bit machines and because stored blocks are restricted to
+* 64K-1 bytes.
+*/
 s->level = level;
 s->strategy = strategy;
 s->method = (Byte)method;
 }
 /* =========================================================================
 * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
 */
-local int deflateStateCheck (strm)
+local int deflateStateCheck(z_streamp strm) {
-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;
 return 1;
 return 0;
 }
 /* ========================================================================= */
-int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
+int ZEXPORT deflateSetDictionary(z_streamp strm, const Bytef *dictionary,
-z_streamp strm;
+uInt  dictLength) {
-const Bytef *dictionary;
-uInt  dictLength;
-{
 deflate_state *s;
 uInt str, n;
 int wrap;
 unsigned avail;
 z_const unsigned char *next;
 s->wrap = wrap;
 return Z_OK;
 }
 /* ========================================================================= */
-int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength)
+int ZEXPORT deflateGetDictionary(z_streamp strm, Bytef *dictionary,
-z_streamp strm;
+uInt *dictLength) {
-Bytef *dictionary;
-uInt  *dictLength;
-{
 deflate_state *s;
 uInt len;
 if (deflateStateCheck(strm))
 return Z_STREAM_ERROR;
 *dictLength = len;
 return Z_OK;
 }
 /* ========================================================================= */
-int ZEXPORT deflateResetKeep (strm)
+int ZEXPORT deflateResetKeep(z_streamp strm) {
-z_streamp strm;
-{
 deflate_state *s;
 if (deflateStateCheck(strm)) {
 return Z_STREAM_ERROR;
 }
 }
 s->status =
 #ifdef GZIP
 s->wrap == 2 ? GZIP_STATE :
 #endif
-s->wrap ? INIT_STATE : BUSY_STATE;
+INIT_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;
+s->last_flush = -2;
 _tr_init(s);
 return Z_OK;
 }
+/* ===========================================================================
+* Initialize the "longest match" routines for a new zlib stream
+*/
+local 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;
+}
 /* ========================================================================= */
-int ZEXPORT deflateReset (strm)
+int ZEXPORT deflateReset(z_streamp strm) {
-z_streamp strm;
-{
 int ret;
 ret = deflateResetKeep(strm);
 if (ret == Z_OK)
 lm_init(strm->state);
 return ret;
 }
 /* ========================================================================= */
-int ZEXPORT deflateSetHeader (strm, head)
+int ZEXPORT deflateSetHeader(z_streamp strm, gz_headerp head) {
-z_streamp strm;
-gz_headerp head;
-{
 if (deflateStateCheck(strm) || strm->state->wrap != 2)
 return Z_STREAM_ERROR;
 strm->state->gzhead = head;
 return Z_OK;
 }
 /* ========================================================================= */
-int ZEXPORT deflatePending (strm, pending, bits)
+int ZEXPORT deflatePending(z_streamp strm, unsigned *pending, int *bits) {
-unsigned *pending;
-int *bits;
-z_streamp strm;
-{
 if (deflateStateCheck(strm)) 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)
+int ZEXPORT deflatePrime(z_streamp strm, int bits, int value) {
-z_streamp strm;
-int bits;
-int value;
-{
 deflate_state *s;
 int put;
 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
 s = strm->state;
-if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
+#ifdef LIT_MEM
+if (bits < 0 || bits > 16 ||
+(uchf *)s->d_buf < s->pending_out + ((Buf_size + 7) >> 3))
 return Z_BUF_ERROR;
+#else
+if (bits < 0 || bits > 16 ||
+s->sym_buf < s->pending_out + ((Buf_size + 7) >> 3))
+return Z_BUF_ERROR;
+#endif
 do {
 put = Buf_size - s->bi_valid;
 if (put > bits)
 put = bits;
 s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
 } while (bits);
 return Z_OK;
 }
 /* ========================================================================= */
-int ZEXPORT deflateParams(strm, level, strategy)
+int ZEXPORT deflateParams(z_streamp strm, int level, int strategy) {
-z_streamp strm;
-int level;
-int strategy;
-{
 deflate_state *s;
 compress_func func;
 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
 s = strm->state;
 return Z_STREAM_ERROR;
 }
 func = configuration_table[s->level].func;
 if ((strategy != s->strategy || func != configuration_table[level].func) &&
-s->high_water) {
+s->last_flush != -2) {
 /* Flush the last buffer: */
 int err = deflate(strm, Z_BLOCK);
 if (err == Z_STREAM_ERROR)
 return err;
-if (strm->avail_out == 0)
+if (strm->avail_in || (s->strstart - s->block_start) + s->lookahead)
 return Z_BUF_ERROR;
 }
 if (s->level != level) {
 if (s->level == 0 && s->matches != 0) {
 if (s->matches == 1)
 s->strategy = strategy;
 return Z_OK;
 }
 /* ========================================================================= */
-int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
+int ZEXPORT deflateTune(z_streamp strm, int good_length, int max_lazy,
-z_streamp strm;
+int nice_length, int max_chain) {
-int good_length;
-int max_lazy;
-int nice_length;
-int max_chain;
-{
 deflate_state *s;
 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
 s = strm->state;
 s->good_match = (uInt)good_length;
 s->max_chain_length = (uInt)max_chain;
 return Z_OK;
 }
 /* =========================================================================
-* For the default windowBits of 15 and memLevel of 8, this function returns
+* For the default windowBits of 15 and memLevel of 8, this function returns a
-* a close to exact, as well as small, upper bound on the compressed size.
+* close to exact, as well as small, upper bound on the compressed size. This
-* They are coded as constants here for a reason--if the #define's are
+* is an expansion of ~0.03%, plus a small constant.
-* 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,
+* For any setting other than those defaults for windowBits and memLevel, one
-* the value returned is a conservative worst case for the maximum expansion
+* of two worst case bounds is returned. This is at most an expansion of ~4% or
-* resulting from using fixed blocks instead of stored blocks, which deflate
+* ~13%, plus a small constant.
-* can emit on compressed data for some combinations of the parameters.
 *
-* This function could be more sophisticated to provide closer upper bounds for
+* Both the 0.03% and 4% derive from the overhead of stored blocks. The first
-* every combination of windowBits and memLevel.  But even the conservative
+* one is for stored blocks of 16383 bytes (memLevel == 8), whereas the second
-* upper bound of about 14% expansion does not seem onerous for output buffer
+* is for stored blocks of 127 bytes (the worst case memLevel == 1). The
-* allocation.
+* expansion results from five bytes of header for each stored block.
-*/
+*
-uLong ZEXPORT deflateBound(strm, sourceLen)
+* The larger expansion of 13% results from a window size less than or equal to
-z_streamp strm;
+* the symbols buffer size (windowBits <= memLevel + 7). In that case some of
-uLong sourceLen;
+* the data being compressed may have slid out of the sliding window, impeding
-{
+* a stored block from being emitted. Then the only choice is a fixed or
+* dynamic block, where a fixed block limits the maximum expansion to 9 bits
+* per 8-bit byte, plus 10 bits for every block. The smallest block size for
+* which this can occur is 255 (memLevel == 2).
+*
+* Shifts are used to approximate divisions, for speed.
+*/
+uLong ZEXPORT deflateBound(z_streamp strm, uLong sourceLen) {
 deflate_state *s;
-uLong complen, wraplen;
+uLong fixedlen, storelen, wraplen;
-/* conservative upper bound for compressed data */
+/* upper bound for fixed blocks with 9-bit literals and length 255
-complen = sourceLen +
+(memLevel == 2, which is the lowest that may not use stored blocks) --
-((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
+~13% overhead plus a small constant */
+fixedlen = sourceLen + (sourceLen >> 3) + (sourceLen >> 8) +
-/* if can't get parameters, return conservative bound plus zlib wrapper */
+(sourceLen >> 9) + 4;
+/* upper bound for stored blocks with length 127 (memLevel == 1) --
+~4% overhead plus a small constant */
+storelen = sourceLen + (sourceLen >> 5) + (sourceLen >> 7) +
+(sourceLen >> 11) + 7;
+/* if can't get parameters, return larger bound plus a zlib wrapper */
 if (deflateStateCheck(strm))
-return complen + 6;
+return (fixedlen > storelen ? fixedlen : storelen) + 6;
 /* compute wrapper length */
 s = strm->state;
 switch (s->wrap) {
 case 0:                                 /* raw deflate */
 #endif
 default:                                /* for compiler happiness */
 wraplen = 6;
 }
-/* if not default parameters, return conservative bound */
+/* if not default parameters, return one of the conservative bounds */
 if (s->w_bits != 15 || s->hash_bits != 8 + 7)
-return complen + wraplen;
+return (s->w_bits <= s->hash_bits && s->level ? fixedlen : storelen) +
+wraplen;
-/* default settings: return tight bound for that case */
+/* default settings: return tight bound for that case -- ~0.03% overhead
+plus a small constant */
 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)
+local void putShortMSB(deflate_state *s, uInt 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, 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()).
 */
-local void flush_pending(strm)
+local void flush_pending(z_streamp strm) {
-z_streamp strm;
-{
 unsigned len;
 deflate_state *s = strm->state;
 _tr_flush_bits(s);
 len = s->pending;
 strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
 s->pending - (beg)); \
 } while (0)
 /* ========================================================================= */
-int ZEXPORT deflate (strm, flush)
+int ZEXPORT deflate(z_streamp strm, int flush) {
-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;
 if (s->status == FINISH_STATE && strm->avail_in != 0) {
 ERR_RETURN(strm, Z_BUF_ERROR);
 }
 /* Write the header */
+if (s->status == INIT_STATE && s->wrap == 0)
+s->status = BUSY_STATE;
 if (s->status == INIT_STATE) {
 /* zlib header */
-uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
+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)
 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)
+int ZEXPORT deflateEnd(z_streamp strm) {
-z_streamp strm;
-{
 int status;
 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
 status = strm->state->status;
 /* =========================================================================
 * 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).
 */
-int ZEXPORT deflateCopy (dest, source)
+int ZEXPORT deflateCopy(z_streamp dest, z_streamp source) {
-z_streamp dest;
-z_streamp source;
-{
 #ifdef MAXSEG_64K
+(void)dest;
+(void)source;
 return Z_STREAM_ERROR;
 #else
 deflate_state *ds;
 deflate_state *ss;
-ushf *overlay;
 if (deflateStateCheck(source) || dest == Z_NULL) {
 return Z_STREAM_ERROR;
 }
 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 *) ZALLOC(dest, ds->lit_bufsize, LIT_BUFS);
-ds->pending_buf = (uchf *) overlay;
 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
 ds->pending_buf == Z_NULL) {
 deflateEnd (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((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
 zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
-zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
+zmemcpy(ds->pending_buf, ss->pending_buf, ds->lit_bufsize * LIT_BUFS);
 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
-ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
+#ifdef LIT_MEM
-ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
+ds->d_buf = (ushf *)(ds->pending_buf + (ds->lit_bufsize << 1));
+ds->l_buf = ds->pending_buf + (ds->lit_bufsize << 2);
+#else
+ds->sym_buf = ds->pending_buf + ds->lit_bufsize;
+#endif
 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()).
-*/
-local unsigned read_buf(strm, buf, size)
-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
-*/
-local void lm_init (s)
-deflate_state *s;
-{
-s->window_size = (ulg)2L*s->w_size;
-CLEAR_HASH(s);
-/* Set the default configuration parameters:
-*/
-s->max_lazy_match   = configuration_table[s->level].max_lazy;
-s->good_match       = configuration_table[s->level].good_length;
-s->nice_match       = configuration_table[s->level].nice_length;
-s->max_chain_length = configuration_table[s->level].max_chain;
-s->strstart = 0;
-s->block_start = 0L;
-s->lookahead = 0;
-s->insert = 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
 * 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
+local uInt longest_match(deflate_state *s, IPos cur_match) {
-/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
-* match.S. The code will be functionally equivalent.
-*/
-local uInt longest_match(s, cur_match)
-deflate_state *s;
-IPos cur_match;                             /* current match */
-{
 unsigned chain_length = s->max_chain_length;/* max hash chain length */
 register Bytef *scan = s->window + s->strstart; /* current string */
 register Bytef *match;                      /* matched string */
 register int len;                           /* length of current match */
 int best_len = (int)s->prev_length;         /* best match length so far */
 /* 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);
+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_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.
 /* 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");
+Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
+"need lookahead");
 do {
 Assert(cur_match < s->strstart, "no future");
 match = s->window + cur_match;
 */
 #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 ||
+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
+* 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
+* 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) &&
+} 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) &&
+*(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 */
+/* Here, scan <= window + strstart + 257 */
-Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+Assert(scan <= s->window + (unsigned)(s->window_size - 1),
+"wild scan");
 if (*scan == *match) scan++;
-len = (MAX_MATCH - 1) - (int)(strend-scan);
+len = (MAX_MATCH - 1) - (int)(strend - scan);
 scan = strend - (MAX_MATCH-1);
 #else /* UNALIGNED_OK */
-if (match[best_len]   != scan_end  ||
+if (match[best_len]     != scan_end  ||
-match[best_len-1] != scan_end1 ||
+match[best_len - 1] != scan_end1 ||
-*match            != *scan     ||
+*match              != *scan     ||
-*++match          != scan[1])      continue;
+*++match            != scan[1])      continue;
-/* The check at best_len-1 can be removed because it will be made
+/* 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.
+* 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");
+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);
+scan_end = *(ushf*)(scan + best_len - 1);
 #else
-scan_end1  = scan[best_len-1];
+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 */
 #else /* FASTEST */
 /* ---------------------------------------------------------------------------
 * Optimized version for FASTEST only
 */
-local uInt longest_match(s, cur_match)
+local uInt longest_match(deflate_state *s, IPos cur_match) {
-deflate_state *s;
-IPos cur_match;                             /* current match */
-{
 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((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
+/* 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.
+* 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");
+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;
 /* result of memcmp for equal strings */
 /* ===========================================================================
 * Check that the match at match_start is indeed a match.
 */
-local void check_match(s, start, match, length)
+local void check_match(deflate_state *s, IPos start, IPos match, int length) {
-deflate_state *s;
-IPos start, match;
-int length;
-{
 /* check that the match is indeed a match */
-if (zmemcmp(s->window + match,
+Bytef *back = s->window + (int)match, *here = s->window + start;
-s->window + start, length) != EQUAL) {
+IPos len = length;
-fprintf(stderr, " start %u, match %u, length %d\n",
+if (match == (IPos)-1) {
-start, match, length);
+/* match starts one byte before the current window -- just compare the
+subsequent length-1 bytes */
+back++;
+here++;
+len--;
+}
+if (zmemcmp(back, here, len) != EQUAL) {
+fprintf(stderr, " start %u, match %d, length %d\n",
+start, (int)match, length);
 do {
-fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
+fprintf(stderr, "(%02x %02x)", *back++, *here++);
-} while (--length != 0);
+} while (--len != 0);
 z_error("invalid match");
 }
 if (z_verbose > 1) {
-fprintf(stderr,"\\[%d,%d]", start-match, length);
+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 /* ZLIB_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).
-*/
-local void fill_window(s)
-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.
 */
 * 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.
+* maximizes the opportunities to have a single copy from next_in to next_out.
 */
-local block_state deflate_stored(s, flush)
+local block_state deflate_stored(deflate_state *s, int flush) {
-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);
 */
 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;
+s->insert = s->strstart;
 }
 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() */
+if (s->insert > s->strstart)
+s->insert = s->strstart;
 }
 zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
 s->strstart += used;
+s->insert += MIN(used, s->w_size - s->insert);
 }
 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 (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;
+have = s->window_size - s->strstart;
 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 (s->insert > s->strstart)
+s->insert = s->strstart;
 }
 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;
+s->insert += MIN(have, s->w_size - s->insert);
 }
 if (s->high_water < s->strstart)
 s->high_water = s->strstart;
 /* There was not enough avail_out to write a complete worthy or flushed
 * 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.
 */
-local block_state deflate_fast(s, flush)
+local block_state deflate_fast(deflate_state *s, int flush) {
-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
 return need_more;
 }
 if (s->lookahead == 0) break; /* flush the current block */
 }
-/* Insert the string window[strstart .. strstart+2] in the
+/* 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);
 #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]);
+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);
+_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)
+if (s->sym_next)
 FLUSH_BLOCK(s, 0);
 return 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.
 */
-local block_state deflate_slow(s, flush)
+local block_state deflate_slow(deflate_state *s, int flush) {
-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 (;;) {
 return need_more;
 }
 if (s->lookahead == 0) break; /* flush the current block */
 }
-/* Insert the string window[strstart .. strstart+2] in the
+/* 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);
 */
 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);
+check_match(s, s->strstart - 1, s->prev_match, s->prev_length);
-_tr_tally_dist(s, s->strstart -1 - s->prev_match,
+_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
+* 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->lookahead -= s->prev_length - 1;
 s->prev_length -= 2;
 do {
 if (++s->strstart <= max_insert) {
 INSERT_STRING(s, s->strstart, hash_head);
 }
 } 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]));
+Tracevv((stderr,"%c", s->window[s->strstart - 1]));
-_tr_tally_lit(s, s->window[s->strstart-1], bflush);
+_tr_tally_lit(s, s->window[s->strstart - 1], bflush);
 if (bflush) {
 FLUSH_BLOCK_ONLY(s, 0);
 }
 s->strstart++;
 s->lookahead--;
 s->lookahead--;
 }
 }
 Assert (flush != Z_NO_FLUSH, "no flush?");
 if (s->match_available) {
-Tracevv((stderr,"%c", s->window[s->strstart-1]));
+Tracevv((stderr,"%c", s->window[s->strstart - 1]));
-_tr_tally_lit(s, s->window[s->strstart-1], bflush);
+_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)
+if (s->sym_next)
 FLUSH_BLOCK(s, 0);
 return block_done;
 }
 #endif /* FASTEST */
 /* ===========================================================================
 * 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)
+local block_state deflate_rle(deflate_state *s, int flush) {
-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 (;;) {
 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");
+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);
 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);
+_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)
+if (s->sym_next)
 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.)
 */
-local block_state deflate_huff(s, flush)
+local block_state deflate_huff(deflate_state *s, int flush) {
-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) {
 }
 /* Output a literal byte */
 s->match_length = 0;
 Tracevv((stderr,"%c", s->window[s->strstart]));
-_tr_tally_lit (s, s->window[s->strstart], bflush);
+_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)
+if (s->sym_next)
 FLUSH_BLOCK(s, 0);
 return block_done;
 }

Mercurial > repos > blastem

comparison zlib/deflate.c @ 2690:9ef72ee5c0b0