[PATCH] zlib_inflate: Upgrade library code to a recent version

Upgrade the zlib_inflate implementation in the kernel from a patched
version 1.1.3/4 to a patched 1.2.3.

The code in the kernel is about seven years old and I noticed that the
external zlib library's inflate performance was significantly faster (~50%)
than the code in the kernel on ARM (and faster again on x86_32).

For comparison the newer deflate code is 20% slower on ARM and 50% slower
on x86_32 but gives an approx 1% compression ratio improvement. I don't
consider this to be an improvement for kernel use so have no plans to
change the zlib_deflate code.

Various changes have been made to the zlib code in the kernel, the most
significant being the extra functions/flush option used by ppp_deflate.
This update reimplements the features PPP needs to ensure it continues to
work.

This code has been tested on ARM under both JFFS2 (with zlib compression
enabled) and ppp_deflate and on x86_32. JFFS2 sees an approx. 10% real
world file read speed improvement.

This patch also removes ZLIB_VERSION as it no longer has a correct value.
We don't need version checks anyway as the kernel's module handling will
take care of that for us. This removal is also more in keeping with the
zlib author's wishes (http://www.zlib.net/zlib_faq.html#faq24) and I've
added something to the zlib.h header to note its a modified version.

Signed-off-by: Richard Purdie <[e-mail]>
Acked-by: Joern Engel <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/powerpc/boot/Makefile

···
 OBJCOPY_COFF_ARGS := -O aixcoff-rs6000 --set-start 0x500000
 OBJCOPY_MIB_ARGS  := -O aixcoff-rs6000 -R .stab -R .stabstr -R .comment
 
-zlib       := infblock.c infcodes.c inffast.c inflate.c inftrees.c infutil.c
-zlibheader := infblock.h infcodes.h inffast.h inftrees.h infutil.h
+zlib       := inffast.c inflate.c inftrees.c
+zlibheader := inffast.h inffixed.h inflate.h inftrees.h infutil.h
 zliblinuxheader := zlib.h zconf.h zutil.h
 
 $(addprefix $(obj)/,$(zlib) main.o): $(addprefix $(obj)/,$(zliblinuxheader)) $(addprefix $(obj)/,$(zlibheader))

arch/ppc/boot/lib/Makefile

···
 CFLAGS_kbd.o	:= -Idrivers/char
 CFLAGS_vreset.o := -Iarch/ppc/boot/include
 
-zlib  := infblock.c infcodes.c inffast.c inflate.c inftrees.c infutil.c
+zlib  := inffast.c inflate.c inftrees.c
 	 
 lib-y += $(zlib:.c=.o) div64.o
 lib-$(CONFIG_VGA_CONSOLE) += vreset.o kbd.o

arch/xtensa/boot/lib/Makefile

···
 # Makefile for some libs needed by zImage.
 #
 
-zlib	:= infblock.c infcodes.c inffast.c inflate.c inftrees.c infutil.c
+zlib	:= inffast.c inflate.c inftrees.c
 
 lib-y	+= $(zlib:.c=.o) zmem.o
 

include/linux/zconf.h

···
 #  define MAX_WBITS   15 /* 32K LZ77 window */
 #endif
 
+/* default windowBits for decompression. MAX_WBITS is for compression only */
+#ifndef DEF_WBITS
+#  define DEF_WBITS MAX_WBITS
+#endif
+
+/* default memLevel */
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+
                         /* Type declarations */
 
 typedef unsigned char  Byte;  /* 8 bits */

include/linux/zlib.h

···
 /* zlib.h -- interface of the 'zlib' general purpose compression library
-  version 1.1.3, July 9th, 1998
 
-  Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
+  Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
···
 
 
   The data format used by the zlib library is described by RFCs (Request for
-  Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
+  Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
 */
 
···
 
 #include <linux/zconf.h>
 
-#define ZLIB_VERSION "1.1.3"
+/* zlib deflate based on ZLIB_VERSION "1.1.3" */
+/* zlib inflate based on ZLIB_VERSION "1.2.3" */
+
+/*
+  This is a modified version of zlib for use inside the Linux kernel.
+  The main changes are to perform all memory allocation in advance.
+
+  Inflation Changes:
+    * Z_PACKET_FLUSH is added and used by ppp_deflate. Before returning
+      this checks there is no more input data available and the next data
+      is a STORED block. It also resets the mode to be read for the next
+      data, all as per PPP requirements.
+    * Addition of zlib_inflateIncomp which copies incompressible data into
+      the history window and adjusts the accoutning without calling
+      zlib_inflate itself to inflate the data.
+*/
 
 /* 
      The 'zlib' compression library provides in-memory compression and
···
   application must provide more input and/or consume the output
   (providing more output space) before each call.
 
+     The compressed data format used by default by the in-memory functions is
+  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
+  around a deflate stream, which is itself documented in RFC 1951.
+
      The library also supports reading and writing files in gzip (.gz) format
   with an interface similar to that of stdio.
+
+     The zlib format was designed to be compact and fast for use in memory
+  and on communications channels.  The gzip format was designed for single-
+  file compression on file systems, has a larger header than zlib to maintain
+  directory information, and uses a different, slower check method than zlib.
 
      The library does not install any signal handler. The decoder checks
   the consistency of the compressed data, so the library should never
···
 #define Z_SYNC_FLUSH    3
 #define Z_FULL_FLUSH    4
 #define Z_FINISH        5
-/* Allowed flush values; see deflate() below for details */
+#define Z_BLOCK         6 /* Only for inflate at present */
+/* Allowed flush values; see deflate() and inflate() below for details */
 
 #define Z_OK            0
 #define Z_STREAM_END    1
···
 /* The deflate compression method (the only one supported in this version) */
 
                         /* basic functions */
-
-extern const char * zlib_zlibVersion (void);
-/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
-   If the first character differs, the library code actually used is
-   not compatible with the zlib.h header file used by the application.
-   This check is automatically made by deflateInit and inflateInit.
- */
 
 extern int zlib_deflate_workspacesize (void);
 /*
···
 extern int zlib_inflate (z_streamp strm, int flush);
 /*
     inflate decompresses as much data as possible, and stops when the input
-  buffer becomes empty or the output buffer becomes full. It may some
-  introduce some output latency (reading input without producing any output)
-  except when forced to flush.
+  buffer becomes empty or the output buffer becomes full. It may introduce
+  some output latency (reading input without producing any output) except when
+  forced to flush.
 
   The detailed semantics are as follows. inflate performs one or both of the
   following actions:
···
   must be called again after making room in the output buffer because there
   might be more output pending.
 
-    If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much
-  output as possible to the output buffer. The flushing behavior of inflate is
-  not specified for values of the flush parameter other than Z_SYNC_FLUSH
-  and Z_FINISH, but the current implementation actually flushes as much output
-  as possible anyway.
+    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
+  Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
+  output as possible to the output buffer. Z_BLOCK requests that inflate() stop
+  if and when it gets to the next deflate block boundary. When decoding the
+  zlib or gzip format, this will cause inflate() to return immediately after
+  the header and before the first block. When doing a raw inflate, inflate()
+  will go ahead and process the first block, and will return when it gets to
+  the end of that block, or when it runs out of data.
+
+    The Z_BLOCK option assists in appending to or combining deflate streams.
+  Also to assist in this, on return inflate() will set strm->data_type to the
+  number of unused bits in the last byte taken from strm->next_in, plus 64
+  if inflate() is currently decoding the last block in the deflate stream,
+  plus 128 if inflate() returned immediately after decoding an end-of-block
+  code or decoding the complete header up to just before the first byte of the
+  deflate stream. The end-of-block will not be indicated until all of the
+  uncompressed data from that block has been written to strm->next_out.  The
+  number of unused bits may in general be greater than seven, except when
+  bit 7 of data_type is set, in which case the number of unused bits will be
+  less than eight.
 
     inflate() should normally be called until it returns Z_STREAM_END or an
   error. However if all decompression is to be performed in a single step
···
   uncompressed data. (The size of the uncompressed data may have been saved
   by the compressor for this purpose.) The next operation on this stream must
   be inflateEnd to deallocate the decompression state. The use of Z_FINISH
-  is never required, but can be used to inform inflate that a faster routine
+  is never required, but can be used to inform inflate that a faster approach
   may be used for the single inflate() call.
 
-     If a preset dictionary is needed at this point (see inflateSetDictionary
-  below), inflate sets strm-adler to the adler32 checksum of the
-  dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise 
-  it sets strm->adler to the adler32 checksum of all output produced
-  so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or
-  an error code as described below. At the end of the stream, inflate()
-  checks that its computed adler32 checksum is equal to that saved by the
-  compressor and returns Z_STREAM_END only if the checksum is correct.
+     In this implementation, inflate() always flushes as much output as
+  possible to the output buffer, and always uses the faster approach on the
+  first call. So the only effect of the flush parameter in this implementation
+  is on the return value of inflate(), as noted below, or when it returns early
+  because Z_BLOCK is used.
+
+     If a preset dictionary is needed after this call (see inflateSetDictionary
+  below), inflate sets strm->adler to the adler32 checksum of the dictionary
+  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
+  strm->adler to the adler32 checksum of all output produced so far (that is,
+  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
+  below. At the end of the stream, inflate() checks that its computed adler32
+  checksum is equal to that saved by the compressor and returns Z_STREAM_END
+  only if the checksum is correct.
+
+    inflate() will decompress and check either zlib-wrapped or gzip-wrapped
+  deflate data.  The header type is detected automatically.  Any information
+  contained in the gzip header is not retained, so applications that need that
+  information should instead use raw inflate, see inflateInit2() below, or
+  inflateBack() and perform their own processing of the gzip header and
+  trailer.
 
     inflate() returns Z_OK if some progress has been made (more input processed
   or more output produced), Z_STREAM_END if the end of the compressed data has
   been reached and all uncompressed output has been produced, Z_NEED_DICT if a
   preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
-  corrupted (input stream not conforming to the zlib format or incorrect
-  adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent
-  (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not
-  enough memory, Z_BUF_ERROR if no progress is possible or if there was not
-  enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR
-  case, the application may then call inflateSync to look for a good
-  compression block.
+  corrupted (input stream not conforming to the zlib format or incorrect check
+  value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
+  if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
+  Z_BUF_ERROR if no progress is possible or if there was not enough room in the
+  output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
+  inflate() can be called again with more input and more output space to
+  continue decompressing. If Z_DATA_ERROR is returned, the application may then
+  call inflateSync() to look for a good compression block if a partial recovery
+  of the data is desired.
 */
 
 
···
      The windowBits parameter is the base two logarithm of the maximum window
    size (the size of the history buffer).  It should be in the range 8..15 for
    this version of the library. The default value is 15 if inflateInit is used
-   instead. If a compressed stream with a larger window size is given as
-   input, inflate() will return with the error code Z_DATA_ERROR instead of
-   trying to allocate a larger window.
+   instead. windowBits must be greater than or equal to the windowBits value
+   provided to deflateInit2() while compressing, or it must be equal to 15 if
+   deflateInit2() was not used. If a compressed stream with a larger window
+   size is given as input, inflate() will return with the error code
+   Z_DATA_ERROR instead of trying to allocate a larger window.
 
-      inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
-   memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative
-   memLevel). msg is set to null if there is no error message.  inflateInit2
-   does not perform any decompression apart from reading the zlib header if
-   present: this will be done by inflate(). (So next_in and avail_in may be
-   modified, but next_out and avail_out are unchanged.)
+     windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
+   determines the window size. inflate() will then process raw deflate data,
+   not looking for a zlib or gzip header, not generating a check value, and not
+   looking for any check values for comparison at the end of the stream. This
+   is for use with other formats that use the deflate compressed data format
+   such as zip.  Those formats provide their own check values. If a custom
+   format is developed using the raw deflate format for compressed data, it is
+   recommended that a check value such as an adler32 or a crc32 be applied to
+   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
+   most applications, the zlib format should be used as is. Note that comments
+   above on the use in deflateInit2() applies to the magnitude of windowBits.
+
+     windowBits can also be greater than 15 for optional gzip decoding. Add
+   32 to windowBits to enable zlib and gzip decoding with automatic header
+   detection, or add 16 to decode only the gzip format (the zlib format will
+   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is
+   a crc32 instead of an adler32.
+
+     inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg
+   is set to null if there is no error message.  inflateInit2 does not perform
+   any decompression apart from reading the zlib header if present: this will
+   be done by inflate(). (So next_in and avail_in may be modified, but next_out
+   and avail_out are unchanged.)
 */
 
 extern int zlib_inflateSetDictionary (z_streamp strm,
···
 						     uInt  dictLength);
 /*
      Initializes the decompression dictionary from the given uncompressed byte
-   sequence. This function must be called immediately after a call of inflate
-   if this call returned Z_NEED_DICT. The dictionary chosen by the compressor
-   can be determined from the Adler32 value returned by this call of
-   inflate. The compressor and decompressor must use exactly the same
-   dictionary (see deflateSetDictionary).
+   sequence. This function must be called immediately after a call of inflate,
+   if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
+   can be determined from the adler32 value returned by that call of inflate.
+   The compressor and decompressor must use exactly the same dictionary (see
+   deflateSetDictionary).  For raw inflate, this function can be called
+   immediately after inflateInit2() or inflateReset() and before any call of
+   inflate() to set the dictionary.  The application must insure that the
+   dictionary that was used for compression is provided.
 
      inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
    parameter is invalid (such as NULL dictionary) or the stream state is
    inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
-   expected one (incorrect Adler32 value). inflateSetDictionary does not
+   expected one (incorrect adler32 value). inflateSetDictionary does not
    perform any decompression: this will be done by subsequent calls of
    inflate().
 */
···
    containing the data at next_in (except that the data is not output).
 */
 
-                        /* various hacks, don't look :) */
-
-/* deflateInit and inflateInit are macros to allow checking the zlib version
- * and the compiler's view of z_stream:
- */
-extern int zlib_deflateInit_ (z_streamp strm, int level,
-                                     const char *version, int stream_size);
-extern int zlib_inflateInit_ (z_streamp strm,
-                                     const char *version, int stream_size);
-extern int zlib_deflateInit2_ (z_streamp strm, int  level, int  method,
-                                      int windowBits, int memLevel,
-                                      int strategy, const char *version,
-                                      int stream_size);
-extern int zlib_inflateInit2_ (z_streamp strm, int  windowBits,
-                                      const char *version, int stream_size);
 #define zlib_deflateInit(strm, level) \
-        zlib_deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
+	zlib_deflateInit2((strm), (level), Z_DEFLATED, MAX_WBITS, \
+			      DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY)
 #define zlib_inflateInit(strm) \
-        zlib_inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
-#define zlib_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
-        zlib_deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
-                      (strategy), ZLIB_VERSION, sizeof(z_stream))
-#define zlib_inflateInit2(strm, windowBits) \
-        zlib_inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
+	zlib_inflateInit2((strm), DEF_WBITS)
 
+extern int zlib_deflateInit2(z_streamp strm, int  level, int  method,
+                                      int windowBits, int memLevel,
+                                      int strategy);
+extern int zlib_inflateInit2(z_streamp strm, int  windowBits);
 
 #if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL)
     struct internal_state {int dummy;}; /* hack for buggy compilers */
 #endif
-
-extern const char  * zlib_zError           (int err);
-#if 0
-extern int           zlib_inflateSyncPoint (z_streamp z);
-#endif
-extern const uLong * zlib_get_crc_table    (void);
 
 #endif /* _ZLIB_H */

include/linux/zutil.h

···
 
         /* common constants */
 
-#ifndef DEF_WBITS
-#  define DEF_WBITS MAX_WBITS
-#endif
-/* default windowBits for decompression. MAX_WBITS is for compression only */
-
-#if MAX_MEM_LEVEL >= 8
-#  define DEF_MEM_LEVEL 8
-#else
-#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
-#endif
-/* default memLevel */
-
 #define STORED_BLOCK 0
 #define STATIC_TREES 1
 #define DYN_TREES    2

lib/zlib_deflate/deflate.c

···
     memset((char *)s->head, 0, (unsigned)(s->hash_size-1)*sizeof(*s->head));
 
 /* ========================================================================= */
-int zlib_deflateInit_(
-	z_streamp strm,
-	int level,
-	const char *version,
-	int stream_size
-)
-{
-    return zlib_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 zlib_deflateInit2_(
+int zlib_deflateInit2(
 	z_streamp strm,
 	int  level,
 	int  method,
 	int  windowBits,
 	int  memLevel,
-	int  strategy,
-	const char *version,
-	int stream_size
+	int  strategy
 )
 {
     deflate_state *s;
     int noheader = 0;
-    static char* my_version = ZLIB_VERSION;
     deflate_workspace *mem;
 
     ush *overlay;
···
      * output size for (length,distance) codes is <= 24 bits.
      */
 
-    if (version == NULL || version[0] != my_version[0] ||
-        stream_size != sizeof(z_stream)) {
-	return Z_VERSION_ERROR;
-    }
     if (strm == NULL) return Z_STREAM_ERROR;
 
     strm->msg = NULL;

lib/zlib_deflate/deflate_syms.c

···
 
 EXPORT_SYMBOL(zlib_deflate_workspacesize);
 EXPORT_SYMBOL(zlib_deflate);
-EXPORT_SYMBOL(zlib_deflateInit_);
-EXPORT_SYMBOL(zlib_deflateInit2_);
+EXPORT_SYMBOL(zlib_deflateInit2);
 EXPORT_SYMBOL(zlib_deflateEnd);
 EXPORT_SYMBOL(zlib_deflateReset);
 MODULE_LICENSE("GPL");

lib/zlib_inflate/Makefile

···
 
 obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate.o
 
-zlib_inflate-objs := infblock.o infcodes.o inffast.o inflate.o \
-		     inflate_sync.o inftrees.o infutil.o inflate_syms.o
+zlib_inflate-objs := inffast.o inflate.o \
+		     inftrees.o inflate_syms.o

lib/zlib_inflate/infblock.c

···
-/* infblock.c -- interpret and process block types to last block
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
- */
-
-#include <linux/zutil.h>
-#include "infblock.h"
-#include "inftrees.h"
-#include "infcodes.h"
-#include "infutil.h"
-
-struct inflate_codes_state;
-
-/* simplify the use of the inflate_huft type with some defines */
-#define exop word.what.Exop
-#define bits word.what.Bits
-
-/* Table for deflate from PKZIP's appnote.txt. */
-static const uInt border[] = { /* Order of the bit length code lengths */
-        16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
-
-/*
-   Notes beyond the 1.93a appnote.txt:
-
-   1. Distance pointers never point before the beginning of the output
-      stream.
-   2. Distance pointers can point back across blocks, up to 32k away.
-   3. There is an implied maximum of 7 bits for the bit length table and
-      15 bits for the actual data.
-   4. If only one code exists, then it is encoded using one bit.  (Zero
-      would be more efficient, but perhaps a little confusing.)  If two
-      codes exist, they are coded using one bit each (0 and 1).
-   5. There is no way of sending zero distance codes--a dummy must be
-      sent if there are none.  (History: a pre 2.0 version of PKZIP would
-      store blocks with no distance codes, but this was discovered to be
-      too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
-      zero distance codes, which is sent as one code of zero bits in
-      length.
-   6. There are up to 286 literal/length codes.  Code 256 represents the
-      end-of-block.  Note however that the static length tree defines
-      288 codes just to fill out the Huffman codes.  Codes 286 and 287
-      cannot be used though, since there is no length base or extra bits
-      defined for them.  Similarily, there are up to 30 distance codes.
-      However, static trees define 32 codes (all 5 bits) to fill out the
-      Huffman codes, but the last two had better not show up in the data.
-   7. Unzip can check dynamic Huffman blocks for complete code sets.
-      The exception is that a single code would not be complete (see #4).
-   8. The five bits following the block type is really the number of
-      literal codes sent minus 257.
-   9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
-      (1+6+6).  Therefore, to output three times the length, you output
-      three codes (1+1+1), whereas to output four times the same length,
-      you only need two codes (1+3).  Hmm.
-  10. In the tree reconstruction algorithm, Code = Code + Increment
-      only if BitLength(i) is not zero.  (Pretty obvious.)
-  11. Correction: 4 Bits: # of Bit Length codes - 4     (4 - 19)
-  12. Note: length code 284 can represent 227-258, but length code 285
-      really is 258.  The last length deserves its own, short code
-      since it gets used a lot in very redundant files.  The length
-      258 is special since 258 - 3 (the min match length) is 255.
-  13. The literal/length and distance code bit lengths are read as a
-      single stream of lengths.  It is possible (and advantageous) for
-      a repeat code (16, 17, or 18) to go across the boundary between
-      the two sets of lengths.
- */
-
-
-void zlib_inflate_blocks_reset(
-	inflate_blocks_statef *s,
-	z_streamp z,
-	uLong *c
-)
-{
-  if (c != NULL)
-    *c = s->check;
-  if (s->mode == CODES)
-    zlib_inflate_codes_free(s->sub.decode.codes, z);
-  s->mode = TYPE;
-  s->bitk = 0;
-  s->bitb = 0;
-  s->read = s->write = s->window;
-  if (s->checkfn != NULL)
-    z->adler = s->check = (*s->checkfn)(0L, NULL, 0);
-}
-
-inflate_blocks_statef *zlib_inflate_blocks_new(
-	z_streamp z,
-	check_func c,
-	uInt w
-)
-{
-  inflate_blocks_statef *s;
-
-  s = &WS(z)->working_blocks_state;
-  s->hufts = WS(z)->working_hufts;
-  s->window = WS(z)->working_window;
-  s->end = s->window + w;
-  s->checkfn = c;
-  s->mode = TYPE;
-  zlib_inflate_blocks_reset(s, z, NULL);
-  return s;
-}
-
-
-int zlib_inflate_blocks(
-	inflate_blocks_statef *s,
-	z_streamp z,
-	int r
-)
-{
-  uInt t;               /* temporary storage */
-  uLong b;              /* bit buffer */
-  uInt k;               /* bits in bit buffer */
-  Byte *p;              /* input data pointer */
-  uInt n;               /* bytes available there */
-  Byte *q;              /* output window write pointer */
-  uInt m;               /* bytes to end of window or read pointer */
-
-  /* copy input/output information to locals (UPDATE macro restores) */
-  LOAD
-
-  /* process input based on current state */
-  while (1) switch (s->mode)
-  {
-    case TYPE:
-      NEEDBITS(3)
-      t = (uInt)b & 7;
-      s->last = t & 1;
-      switch (t >> 1)
-      {
-        case 0:                         /* stored */
-          DUMPBITS(3)
-          t = k & 7;                    /* go to byte boundary */
-          DUMPBITS(t)
-          s->mode = LENS;               /* get length of stored block */
-          break;
-        case 1:                         /* fixed */
-          {
-            uInt bl, bd;
-            inflate_huft *tl, *td;
-
-            zlib_inflate_trees_fixed(&bl, &bd, &tl, &td, s->hufts, z);
-            s->sub.decode.codes = zlib_inflate_codes_new(bl, bd, tl, td, z);
-            if (s->sub.decode.codes == NULL)
-            {
-              r = Z_MEM_ERROR;
-              LEAVE
-            }
-          }
-          DUMPBITS(3)
-          s->mode = CODES;
-          break;
-        case 2:                         /* dynamic */
-          DUMPBITS(3)
-          s->mode = TABLE;
-          break;
-        case 3:                         /* illegal */
-          DUMPBITS(3)
-          s->mode = B_BAD;
-          z->msg = (char*)"invalid block type";
-          r = Z_DATA_ERROR;
-          LEAVE
-      }
-      break;
-    case LENS:
-      NEEDBITS(32)
-      if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
-      {
-        s->mode = B_BAD;
-        z->msg = (char*)"invalid stored block lengths";
-        r = Z_DATA_ERROR;
-        LEAVE
-      }
-      s->sub.left = (uInt)b & 0xffff;
-      b = k = 0;                      /* dump bits */
-      s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
-      break;
-    case STORED:
-      if (n == 0)
-        LEAVE
-      NEEDOUT
-      t = s->sub.left;
-      if (t > n) t = n;
-      if (t > m) t = m;
-      memcpy(q, p, t);
-      p += t;  n -= t;
-      q += t;  m -= t;
-      if ((s->sub.left -= t) != 0)
-        break;
-      s->mode = s->last ? DRY : TYPE;
-      break;
-    case TABLE:
-      NEEDBITS(14)
-      s->sub.trees.table = t = (uInt)b & 0x3fff;
-#ifndef PKZIP_BUG_WORKAROUND
-      if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
-      {
-        s->mode = B_BAD;
-        z->msg = (char*)"too many length or distance symbols";
-        r = Z_DATA_ERROR;
-        LEAVE
-      }
-#endif
-      {
-      	s->sub.trees.blens = WS(z)->working_blens;
-      }
-      DUMPBITS(14)
-      s->sub.trees.index = 0;
-      s->mode = BTREE;
-    case BTREE:
-      while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
-      {
-        NEEDBITS(3)
-        s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
-        DUMPBITS(3)
-      }
-      while (s->sub.trees.index < 19)
-        s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
-      s->sub.trees.bb = 7;
-      t = zlib_inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
-				  &s->sub.trees.tb, s->hufts, z);
-      if (t != Z_OK)
-      {
-        r = t;
-        if (r == Z_DATA_ERROR)
-          s->mode = B_BAD;
-        LEAVE
-      }
-      s->sub.trees.index = 0;
-      s->mode = DTREE;
-    case DTREE:
-      while (t = s->sub.trees.table,
-             s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
-      {
-        inflate_huft *h;
-        uInt i, j, c;
-
-        t = s->sub.trees.bb;
-        NEEDBITS(t)
-        h = s->sub.trees.tb + ((uInt)b & zlib_inflate_mask[t]);
-        t = h->bits;
-        c = h->base;
-        if (c < 16)
-        {
-          DUMPBITS(t)
-          s->sub.trees.blens[s->sub.trees.index++] = c;
-        }
-        else /* c == 16..18 */
-        {
-          i = c == 18 ? 7 : c - 14;
-          j = c == 18 ? 11 : 3;
-          NEEDBITS(t + i)
-          DUMPBITS(t)
-          j += (uInt)b & zlib_inflate_mask[i];
-          DUMPBITS(i)
-          i = s->sub.trees.index;
-          t = s->sub.trees.table;
-          if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
-              (c == 16 && i < 1))
-          {
-            s->mode = B_BAD;
-            z->msg = (char*)"invalid bit length repeat";
-            r = Z_DATA_ERROR;
-            LEAVE
-          }
-          c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
-          do {
-            s->sub.trees.blens[i++] = c;
-          } while (--j);
-          s->sub.trees.index = i;
-        }
-      }
-      s->sub.trees.tb = NULL;
-      {
-        uInt bl, bd;
-        inflate_huft *tl, *td;
-        inflate_codes_statef *c;
-
-        bl = 9;         /* must be <= 9 for lookahead assumptions */
-        bd = 6;         /* must be <= 9 for lookahead assumptions */
-        t = s->sub.trees.table;
-        t = zlib_inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
-				       s->sub.trees.blens, &bl, &bd, &tl, &td,
-				       s->hufts, z);
-        if (t != Z_OK)
-        {
-          if (t == (uInt)Z_DATA_ERROR)
-            s->mode = B_BAD;
-          r = t;
-          LEAVE
-        }
-        if ((c = zlib_inflate_codes_new(bl, bd, tl, td, z)) == NULL)
-        {
-          r = Z_MEM_ERROR;
-          LEAVE
-        }
-        s->sub.decode.codes = c;
-      }
-      s->mode = CODES;
-    case CODES:
-      UPDATE
-      if ((r = zlib_inflate_codes(s, z, r)) != Z_STREAM_END)
-        return zlib_inflate_flush(s, z, r);
-      r = Z_OK;
-      zlib_inflate_codes_free(s->sub.decode.codes, z);
-      LOAD
-      if (!s->last)
-      {
-        s->mode = TYPE;
-        break;
-      }
-      s->mode = DRY;
-    case DRY:
-      FLUSH
-      if (s->read != s->write)
-        LEAVE
-      s->mode = B_DONE;
-    case B_DONE:
-      r = Z_STREAM_END;
-      LEAVE
-    case B_BAD:
-      r = Z_DATA_ERROR;
-      LEAVE
-    default:
-      r = Z_STREAM_ERROR;
-      LEAVE
-  }
-}
-
-
-int zlib_inflate_blocks_free(
-	inflate_blocks_statef *s,
-	z_streamp z
-)
-{
-  zlib_inflate_blocks_reset(s, z, NULL);
-  return Z_OK;
-}
-
-
-#if 0
-void zlib_inflate_set_dictionary(
-	inflate_blocks_statef *s,
-	const Byte *d,
-	uInt  n
-)
-{
-  memcpy(s->window, d, n);
-  s->read = s->write = s->window + n;
-}
-#endif  /*  0  */
-
-
-/* Returns true if inflate is currently at the end of a block generated
- * by Z_SYNC_FLUSH or Z_FULL_FLUSH. 
- * IN assertion: s != NULL
- */
-#if 0
-int zlib_inflate_blocks_sync_point(
-	inflate_blocks_statef *s
-)
-{
-  return s->mode == LENS;
-}
-#endif  /*  0  */

lib/zlib_inflate/infblock.h

···
-/* infblock.h -- header to use infblock.c
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
- */
-
-/* WARNING: this file should *not* be used by applications. It is
-   part of the implementation of the compression library and is
-   subject to change. Applications should only use zlib.h.
- */
-
-#ifndef _INFBLOCK_H
-#define _INFBLOCK_H
-
-struct inflate_blocks_state;
-typedef struct inflate_blocks_state inflate_blocks_statef;
-
-extern inflate_blocks_statef * zlib_inflate_blocks_new (
-    z_streamp z,
-    check_func c,              /* check function */
-    uInt w);                   /* window size */
-
-extern int zlib_inflate_blocks (
-    inflate_blocks_statef *,
-    z_streamp ,
-    int);                      /* initial return code */
-
-extern void zlib_inflate_blocks_reset (
-    inflate_blocks_statef *,
-    z_streamp ,
-    uLong *);                  /* check value on output */
-
-extern int zlib_inflate_blocks_free (
-    inflate_blocks_statef *,
-    z_streamp);
-
-#if 0
-extern void zlib_inflate_set_dictionary (
-    inflate_blocks_statef *s,
-    const Byte *d,  /* dictionary */
-    uInt  n);       /* dictionary length */
-#endif  /*  0  */
-
-#if 0
-extern int zlib_inflate_blocks_sync_point (
-    inflate_blocks_statef *s);
-#endif  /*  0  */
-
-#endif /* _INFBLOCK_H */

lib/zlib_inflate/infcodes.c

···
-/* infcodes.c -- process literals and length/distance pairs
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
- */
-
-#include <linux/zutil.h>
-#include "inftrees.h"
-#include "infblock.h"
-#include "infcodes.h"
-#include "infutil.h"
-#include "inffast.h"
-
-/* simplify the use of the inflate_huft type with some defines */
-#define exop word.what.Exop
-#define bits word.what.Bits
-
-inflate_codes_statef *zlib_inflate_codes_new(
-	uInt bl,
-	uInt bd,
-	inflate_huft *tl,
-	inflate_huft *td, /* need separate declaration for Borland C++ */
-	z_streamp z
-)
-{
-  inflate_codes_statef *c;
-
-  c = &WS(z)->working_state;
-  {
-    c->mode = START;
-    c->lbits = (Byte)bl;
-    c->dbits = (Byte)bd;
-    c->ltree = tl;
-    c->dtree = td;
-  }
-  return c;
-}
-
-
-int zlib_inflate_codes(
-	inflate_blocks_statef *s,
-	z_streamp z,
-	int r
-)
-{
-  uInt j;               /* temporary storage */
-  inflate_huft *t;      /* temporary pointer */
-  uInt e;               /* extra bits or operation */
-  uLong b;              /* bit buffer */
-  uInt k;               /* bits in bit buffer */
-  Byte *p;              /* input data pointer */
-  uInt n;               /* bytes available there */
-  Byte *q;              /* output window write pointer */
-  uInt m;               /* bytes to end of window or read pointer */
-  Byte *f;              /* pointer to copy strings from */
-  inflate_codes_statef *c = s->sub.decode.codes;  /* codes state */
-
-  /* copy input/output information to locals (UPDATE macro restores) */
-  LOAD
-
-  /* process input and output based on current state */
-  while (1) switch (c->mode)
-  {             /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
-    case START:         /* x: set up for LEN */
-#ifndef SLOW
-      if (m >= 258 && n >= 10)
-      {
-        UPDATE
-        r = zlib_inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
-        LOAD
-        if (r != Z_OK)
-        {
-          c->mode = r == Z_STREAM_END ? WASH : BADCODE;
-          break;
-        }
-      }
-#endif /* !SLOW */
-      c->sub.code.need = c->lbits;
-      c->sub.code.tree = c->ltree;
-      c->mode = LEN;
-    case LEN:           /* i: get length/literal/eob next */
-      j = c->sub.code.need;
-      NEEDBITS(j)
-      t = c->sub.code.tree + ((uInt)b & zlib_inflate_mask[j]);
-      DUMPBITS(t->bits)
-      e = (uInt)(t->exop);
-      if (e == 0)               /* literal */
-      {
-        c->sub.lit = t->base;
-        c->mode = LIT;
-        break;
-      }
-      if (e & 16)               /* length */
-      {
-        c->sub.copy.get = e & 15;
-        c->len = t->base;
-        c->mode = LENEXT;
-        break;
-      }
-      if ((e & 64) == 0)        /* next table */
-      {
-        c->sub.code.need = e;
-        c->sub.code.tree = t + t->base;
-        break;
-      }
-      if (e & 32)               /* end of block */
-      {
-        c->mode = WASH;
-        break;
-      }
-      c->mode = BADCODE;        /* invalid code */
-      z->msg = (char*)"invalid literal/length code";
-      r = Z_DATA_ERROR;
-      LEAVE
-    case LENEXT:        /* i: getting length extra (have base) */
-      j = c->sub.copy.get;
-      NEEDBITS(j)
-      c->len += (uInt)b & zlib_inflate_mask[j];
-      DUMPBITS(j)
-      c->sub.code.need = c->dbits;
-      c->sub.code.tree = c->dtree;
-      c->mode = DIST;
-    case DIST:          /* i: get distance next */
-      j = c->sub.code.need;
-      NEEDBITS(j)
-      t = c->sub.code.tree + ((uInt)b & zlib_inflate_mask[j]);
-      DUMPBITS(t->bits)
-      e = (uInt)(t->exop);
-      if (e & 16)               /* distance */
-      {
-        c->sub.copy.get = e & 15;
-        c->sub.copy.dist = t->base;
-        c->mode = DISTEXT;
-        break;
-      }
-      if ((e & 64) == 0)        /* next table */
-      {
-        c->sub.code.need = e;
-        c->sub.code.tree = t + t->base;
-        break;
-      }
-      c->mode = BADCODE;        /* invalid code */
-      z->msg = (char*)"invalid distance code";
-      r = Z_DATA_ERROR;
-      LEAVE
-    case DISTEXT:       /* i: getting distance extra */
-      j = c->sub.copy.get;
-      NEEDBITS(j)
-      c->sub.copy.dist += (uInt)b & zlib_inflate_mask[j];
-      DUMPBITS(j)
-      c->mode = COPY;
-    case COPY:          /* o: copying bytes in window, waiting for space */
-      f = q - c->sub.copy.dist;
-      while (f < s->window)             /* modulo window size-"while" instead */
-        f += s->end - s->window;        /* of "if" handles invalid distances */
-      while (c->len)
-      {
-        NEEDOUT
-        OUTBYTE(*f++)
-        if (f == s->end)
-          f = s->window;
-        c->len--;
-      }
-      c->mode = START;
-      break;
-    case LIT:           /* o: got literal, waiting for output space */
-      NEEDOUT
-      OUTBYTE(c->sub.lit)
-      c->mode = START;
-      break;
-    case WASH:          /* o: got eob, possibly more output */
-      if (k > 7)        /* return unused byte, if any */
-      {
-        k -= 8;
-        n++;
-        p--;            /* can always return one */
-      }
-      FLUSH
-      if (s->read != s->write)
-        LEAVE
-      c->mode = END;
-    case END:
-      r = Z_STREAM_END;
-      LEAVE
-    case BADCODE:       /* x: got error */
-      r = Z_DATA_ERROR;
-      LEAVE
-    default:
-      r = Z_STREAM_ERROR;
-      LEAVE
-  }
-#ifdef NEED_DUMMY_RETURN
-  return Z_STREAM_ERROR;  /* Some dumb compilers complain without this */
-#endif
-}
-
-
-void zlib_inflate_codes_free(
-	inflate_codes_statef *c,
-	z_streamp z
-)
-{
-}

lib/zlib_inflate/infcodes.h

···
-/* infcodes.h -- header to use infcodes.c
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
- */
-
-/* WARNING: this file should *not* be used by applications. It is
-   part of the implementation of the compression library and is
-   subject to change. Applications should only use zlib.h.
- */
-
-#ifndef _INFCODES_H
-#define _INFCODES_H
-
-#include "infblock.h"
-
-struct inflate_codes_state;
-typedef struct inflate_codes_state inflate_codes_statef;
-
-extern inflate_codes_statef *zlib_inflate_codes_new (
-    uInt, uInt,
-    inflate_huft *, inflate_huft *,
-    z_streamp );
-
-extern int zlib_inflate_codes (
-    inflate_blocks_statef *,
-    z_streamp ,
-    int);
-
-extern void zlib_inflate_codes_free (
-    inflate_codes_statef *,
-    z_streamp );
-
-#endif /* _INFCODES_H */

lib/zlib_inflate/inffast.c

···
-/* inffast.c -- process literals and length/distance pairs fast
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
+/* inffast.c -- fast decoding
+ * Copyright (C) 1995-2004 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 #include <linux/zutil.h>
 #include "inftrees.h"
-#include "infblock.h"
-#include "infcodes.h"
-#include "infutil.h"
+#include "inflate.h"
 #include "inffast.h"
 
-struct inflate_codes_state;
+#ifndef ASMINF
 
-/* simplify the use of the inflate_huft type with some defines */
-#define exop word.what.Exop
-#define bits word.what.Bits
+/* Allow machine dependent optimization for post-increment or pre-increment.
+   Based on testing to date,
+   Pre-increment preferred for:
+   - PowerPC G3 (Adler)
+   - MIPS R5000 (Randers-Pehrson)
+   Post-increment preferred for:
+   - none
+   No measurable difference:
+   - Pentium III (Anderson)
+   - M68060 (Nikl)
+ */
+#ifdef POSTINC
+#  define OFF 0
+#  define PUP(a) *(a)++
+#else
+#  define OFF 1
+#  define PUP(a) *++(a)
+#endif
 
-/* macros for bit input with no checking and for returning unused bytes */
-#define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
-#define UNGRAB {c=z->avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;}
+/*
+   Decode literal, length, and distance codes and write out the resulting
+   literal and match bytes until either not enough input or output is
+   available, an end-of-block is encountered, or a data error is encountered.
+   When large enough input and output buffers are supplied to inflate(), for
+   example, a 16K input buffer and a 64K output buffer, more than 95% of the
+   inflate execution time is spent in this routine.
 
-/* Called with number of bytes left to write in window at least 258
-   (the maximum string length) and number of input bytes available
-   at least ten.  The ten bytes are six bytes for the longest length/
-   distance pair plus four bytes for overloading the bit buffer. */
+   Entry assumptions:
 
-int zlib_inflate_fast(
-	uInt bl,
-	uInt bd,
-	inflate_huft *tl,
-	inflate_huft *td, /* need separate declaration for Borland C++ */
-	inflate_blocks_statef *s,
-	z_streamp z
-)
+        state->mode == LEN
+        strm->avail_in >= 6
+        strm->avail_out >= 258
+        start >= strm->avail_out
+        state->bits < 8
+
+   On return, state->mode is one of:
+
+        LEN -- ran out of enough output space or enough available input
+        TYPE -- reached end of block code, inflate() to interpret next block
+        BAD -- error in block data
+
+   Notes:
+
+    - The maximum input bits used by a length/distance pair is 15 bits for the
+      length code, 5 bits for the length extra, 15 bits for the distance code,
+      and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
+      Therefore if strm->avail_in >= 6, then there is enough input to avoid
+      checking for available input while decoding.
+
+    - The maximum bytes that a single length/distance pair can output is 258
+      bytes, which is the maximum length that can be coded.  inflate_fast()
+      requires strm->avail_out >= 258 for each loop to avoid checking for
+      output space.
+ */
+void inflate_fast(strm, start)
+z_streamp strm;
+unsigned start;         /* inflate()'s starting value for strm->avail_out */
 {
-  inflate_huft *t;      /* temporary pointer */
-  uInt e;               /* extra bits or operation */
-  uLong b;              /* bit buffer */
-  uInt k;               /* bits in bit buffer */
-  Byte *p;              /* input data pointer */
-  uInt n;               /* bytes available there */
-  Byte *q;              /* output window write pointer */
-  uInt m;               /* bytes to end of window or read pointer */
-  uInt ml;              /* mask for literal/length tree */
-  uInt md;              /* mask for distance tree */
-  uInt c;               /* bytes to copy */
-  uInt d;               /* distance back to copy from */
-  Byte *r;              /* copy source pointer */
+    struct inflate_state *state;
+    unsigned char *in;      /* local strm->next_in */
+    unsigned char *last;    /* while in < last, enough input available */
+    unsigned char *out;     /* local strm->next_out */
+    unsigned char *beg;     /* inflate()'s initial strm->next_out */
+    unsigned char *end;     /* while out < end, enough space available */
+#ifdef INFLATE_STRICT
+    unsigned dmax;              /* maximum distance from zlib header */
+#endif
+    unsigned wsize;             /* window size or zero if not using window */
+    unsigned whave;             /* valid bytes in the window */
+    unsigned write;             /* window write index */
+    unsigned char *window;  /* allocated sliding window, if wsize != 0 */
+    unsigned long hold;         /* local strm->hold */
+    unsigned bits;              /* local strm->bits */
+    code const *lcode;      /* local strm->lencode */
+    code const *dcode;      /* local strm->distcode */
+    unsigned lmask;             /* mask for first level of length codes */
+    unsigned dmask;             /* mask for first level of distance codes */
+    code this;                  /* retrieved table entry */
+    unsigned op;                /* code bits, operation, extra bits, or */
+                                /*  window position, window bytes to copy */
+    unsigned len;               /* match length, unused bytes */
+    unsigned dist;              /* match distance */
+    unsigned char *from;    /* where to copy match from */
 
-  /* load input, output, bit values */
-  LOAD
+    /* copy state to local variables */
+    state = (struct inflate_state *)strm->state;
+    in = strm->next_in - OFF;
+    last = in + (strm->avail_in - 5);
+    out = strm->next_out - OFF;
+    beg = out - (start - strm->avail_out);
+    end = out + (strm->avail_out - 257);
+#ifdef INFLATE_STRICT
+    dmax = state->dmax;
+#endif
+    wsize = state->wsize;
+    whave = state->whave;
+    write = state->write;
+    window = state->window;
+    hold = state->hold;
+    bits = state->bits;
+    lcode = state->lencode;
+    dcode = state->distcode;
+    lmask = (1U << state->lenbits) - 1;
+    dmask = (1U << state->distbits) - 1;
 
-  /* initialize masks */
-  ml = zlib_inflate_mask[bl];
-  md = zlib_inflate_mask[bd];
-
-  /* do until not enough input or output space for fast loop */
-  do {                          /* assume called with m >= 258 && n >= 10 */
-    /* get literal/length code */
-    GRABBITS(20)                /* max bits for literal/length code */
-    if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
-    {
-      DUMPBITS(t->bits)
-      *q++ = (Byte)t->base;
-      m--;
-      continue;
-    }
+    /* decode literals and length/distances until end-of-block or not enough
+       input data or output space */
     do {
-      DUMPBITS(t->bits)
-      if (e & 16)
-      {
-        /* get extra bits for length */
-        e &= 15;
-        c = t->base + ((uInt)b & zlib_inflate_mask[e]);
-        DUMPBITS(e)
-
-        /* decode distance base of block to copy */
-        GRABBITS(15);           /* max bits for distance code */
-        e = (t = td + ((uInt)b & md))->exop;
-        do {
-          DUMPBITS(t->bits)
-          if (e & 16)
-          {
-            /* get extra bits to add to distance base */
-            e &= 15;
-            GRABBITS(e)         /* get extra bits (up to 13) */
-            d = t->base + ((uInt)b & zlib_inflate_mask[e]);
-            DUMPBITS(e)
-
-            /* do the copy */
-            m -= c;
-            r = q - d;
-            if (r < s->window)                  /* wrap if needed */
-            {
-              do {
-                r += s->end - s->window;        /* force pointer in window */
-              } while (r < s->window);          /* covers invalid distances */
-              e = s->end - r;
-              if (c > e)
-              {
-                c -= e;                         /* wrapped copy */
-                do {
-                    *q++ = *r++;
-                } while (--e);
-                r = s->window;
-                do {
-                    *q++ = *r++;
-                } while (--c);
-              }
-              else                              /* normal copy */
-              {
-                *q++ = *r++;  c--;
-                *q++ = *r++;  c--;
-                do {
-                    *q++ = *r++;
-                } while (--c);
-              }
-            }
-            else                                /* normal copy */
-            {
-              *q++ = *r++;  c--;
-              *q++ = *r++;  c--;
-              do {
-                *q++ = *r++;
-              } while (--c);
-            }
-            break;
-          }
-          else if ((e & 64) == 0)
-          {
-            t += t->base;
-            e = (t += ((uInt)b & zlib_inflate_mask[e]))->exop;
-          }
-          else
-          {
-            z->msg = (char*)"invalid distance code";
-            UNGRAB
-            UPDATE
-            return Z_DATA_ERROR;
-          }
-        } while (1);
-        break;
-      }
-      if ((e & 64) == 0)
-      {
-        t += t->base;
-        if ((e = (t += ((uInt)b & zlib_inflate_mask[e]))->exop) == 0)
-        {
-          DUMPBITS(t->bits)
-          *q++ = (Byte)t->base;
-          m--;
-          break;
+        if (bits < 15) {
+            hold += (unsigned long)(PUP(in)) << bits;
+            bits += 8;
+            hold += (unsigned long)(PUP(in)) << bits;
+            bits += 8;
         }
-      }
-      else if (e & 32)
-      {
-        UNGRAB
-        UPDATE
-        return Z_STREAM_END;
-      }
-      else
-      {
-        z->msg = (char*)"invalid literal/length code";
-        UNGRAB
-        UPDATE
-        return Z_DATA_ERROR;
-      }
-    } while (1);
-  } while (m >= 258 && n >= 10);
+        this = lcode[hold & lmask];
+      dolen:
+        op = (unsigned)(this.bits);
+        hold >>= op;
+        bits -= op;
+        op = (unsigned)(this.op);
+        if (op == 0) {                          /* literal */
+            PUP(out) = (unsigned char)(this.val);
+        }
+        else if (op & 16) {                     /* length base */
+            len = (unsigned)(this.val);
+            op &= 15;                           /* number of extra bits */
+            if (op) {
+                if (bits < op) {
+                    hold += (unsigned long)(PUP(in)) << bits;
+                    bits += 8;
+                }
+                len += (unsigned)hold & ((1U << op) - 1);
+                hold >>= op;
+                bits -= op;
+            }
+            if (bits < 15) {
+                hold += (unsigned long)(PUP(in)) << bits;
+                bits += 8;
+                hold += (unsigned long)(PUP(in)) << bits;
+                bits += 8;
+            }
+            this = dcode[hold & dmask];
+          dodist:
+            op = (unsigned)(this.bits);
+            hold >>= op;
+            bits -= op;
+            op = (unsigned)(this.op);
+            if (op & 16) {                      /* distance base */
+                dist = (unsigned)(this.val);
+                op &= 15;                       /* number of extra bits */
+                if (bits < op) {
+                    hold += (unsigned long)(PUP(in)) << bits;
+                    bits += 8;
+                    if (bits < op) {
+                        hold += (unsigned long)(PUP(in)) << bits;
+                        bits += 8;
+                    }
+                }
+                dist += (unsigned)hold & ((1U << op) - 1);
+#ifdef INFLATE_STRICT
+                if (dist > dmax) {
+                    strm->msg = (char *)"invalid distance too far back";
+                    state->mode = BAD;
+                    break;
+                }
+#endif
+                hold >>= op;
+                bits -= op;
+                op = (unsigned)(out - beg);     /* max distance in output */
+                if (dist > op) {                /* see if copy from window */
+                    op = dist - op;             /* distance back in window */
+                    if (op > whave) {
+                        strm->msg = (char *)"invalid distance too far back";
+                        state->mode = BAD;
+                        break;
+                    }
+                    from = window - OFF;
+                    if (write == 0) {           /* very common case */
+                        from += wsize - op;
+                        if (op < len) {         /* some from window */
+                            len -= op;
+                            do {
+                                PUP(out) = PUP(from);
+                            } while (--op);
+                            from = out - dist;  /* rest from output */
+                        }
+                    }
+                    else if (write < op) {      /* wrap around window */
+                        from += wsize + write - op;
+                        op -= write;
+                        if (op < len) {         /* some from end of window */
+                            len -= op;
+                            do {
+                                PUP(out) = PUP(from);
+                            } while (--op);
+                            from = window - OFF;
+                            if (write < len) {  /* some from start of window */
+                                op = write;
+                                len -= op;
+                                do {
+                                    PUP(out) = PUP(from);
+                                } while (--op);
+                                from = out - dist;      /* rest from output */
+                            }
+                        }
+                    }
+                    else {                      /* contiguous in window */
+                        from += write - op;
+                        if (op < len) {         /* some from window */
+                            len -= op;
+                            do {
+                                PUP(out) = PUP(from);
+                            } while (--op);
+                            from = out - dist;  /* rest from output */
+                        }
+                    }
+                    while (len > 2) {
+                        PUP(out) = PUP(from);
+                        PUP(out) = PUP(from);
+                        PUP(out) = PUP(from);
+                        len -= 3;
+                    }
+                    if (len) {
+                        PUP(out) = PUP(from);
+                        if (len > 1)
+                            PUP(out) = PUP(from);
+                    }
+                }
+                else {
+                    from = out - dist;          /* copy direct from output */
+                    do {                        /* minimum length is three */
+                        PUP(out) = PUP(from);
+                        PUP(out) = PUP(from);
+                        PUP(out) = PUP(from);
+                        len -= 3;
+                    } while (len > 2);
+                    if (len) {
+                        PUP(out) = PUP(from);
+                        if (len > 1)
+                            PUP(out) = PUP(from);
+                    }
+                }
+            }
+            else if ((op & 64) == 0) {          /* 2nd level distance code */
+                this = dcode[this.val + (hold & ((1U << op) - 1))];
+                goto dodist;
+            }
+            else {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+        }
+        else if ((op & 64) == 0) {              /* 2nd level length code */
+            this = lcode[this.val + (hold & ((1U << op) - 1))];
+            goto dolen;
+        }
+        else if (op & 32) {                     /* end-of-block */
+            state->mode = TYPE;
+            break;
+        }
+        else {
+            strm->msg = (char *)"invalid literal/length code";
+            state->mode = BAD;
+            break;
+        }
+    } while (in < last && out < end);
 
-  /* not enough input or output--restore pointers and return */
-  UNGRAB
-  UPDATE
-  return Z_OK;
+    /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
+    len = bits >> 3;
+    in -= len;
+    bits -= len << 3;
+    hold &= (1U << bits) - 1;
+
+    /* update state and return */
+    strm->next_in = in + OFF;
+    strm->next_out = out + OFF;
+    strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
+    strm->avail_out = (unsigned)(out < end ?
+                                 257 + (end - out) : 257 - (out - end));
+    state->hold = hold;
+    state->bits = bits;
+    return;
 }
+
+/*
+   inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):
+   - Using bit fields for code structure
+   - Different op definition to avoid & for extra bits (do & for table bits)
+   - Three separate decoding do-loops for direct, window, and write == 0
+   - Special case for distance > 1 copies to do overlapped load and store copy
+   - Explicit branch predictions (based on measured branch probabilities)
+   - Deferring match copy and interspersed it with decoding subsequent codes
+   - Swapping literal/length else
+   - Swapping window/direct else
+   - Larger unrolled copy loops (three is about right)
+   - Moving len -= 3 statement into middle of loop
+ */
+
+#endif /* !ASMINF */

lib/zlib_inflate/inffast.h

···
 /* inffast.h -- header to use inffast.c
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /* WARNING: this file should *not* be used by applications. It is
···
    subject to change. Applications should only use zlib.h.
  */
 
-extern int zlib_inflate_fast (
-    uInt,
-    uInt,
-    inflate_huft *,
-    inflate_huft *,
-    inflate_blocks_statef *,
-    z_streamp );
+void inflate_fast (z_streamp strm, unsigned start);

lib/zlib_inflate/inffixed.h

···
+    /* inffixed.h -- table for decoding fixed codes
+     * Generated automatically by makefixed().
+     */
+
+    /* WARNING: this file should *not* be used by applications. It
+       is part of the implementation of the compression library and
+       is subject to change. Applications should only use zlib.h.
+     */
+
+    static const code lenfix[512] = {
+        {96,7,0},{0,8,80},{0,8,16},{20,8,115},{18,7,31},{0,8,112},{0,8,48},
+        {0,9,192},{16,7,10},{0,8,96},{0,8,32},{0,9,160},{0,8,0},{0,8,128},
+        {0,8,64},{0,9,224},{16,7,6},{0,8,88},{0,8,24},{0,9,144},{19,7,59},
+        {0,8,120},{0,8,56},{0,9,208},{17,7,17},{0,8,104},{0,8,40},{0,9,176},
+        {0,8,8},{0,8,136},{0,8,72},{0,9,240},{16,7,4},{0,8,84},{0,8,20},
+        {21,8,227},{19,7,43},{0,8,116},{0,8,52},{0,9,200},{17,7,13},{0,8,100},
+        {0,8,36},{0,9,168},{0,8,4},{0,8,132},{0,8,68},{0,9,232},{16,7,8},
+        {0,8,92},{0,8,28},{0,9,152},{20,7,83},{0,8,124},{0,8,60},{0,9,216},
+        {18,7,23},{0,8,108},{0,8,44},{0,9,184},{0,8,12},{0,8,140},{0,8,76},
+        {0,9,248},{16,7,3},{0,8,82},{0,8,18},{21,8,163},{19,7,35},{0,8,114},
+        {0,8,50},{0,9,196},{17,7,11},{0,8,98},{0,8,34},{0,9,164},{0,8,2},
+        {0,8,130},{0,8,66},{0,9,228},{16,7,7},{0,8,90},{0,8,26},{0,9,148},
+        {20,7,67},{0,8,122},{0,8,58},{0,9,212},{18,7,19},{0,8,106},{0,8,42},
+        {0,9,180},{0,8,10},{0,8,138},{0,8,74},{0,9,244},{16,7,5},{0,8,86},
+        {0,8,22},{64,8,0},{19,7,51},{0,8,118},{0,8,54},{0,9,204},{17,7,15},
+        {0,8,102},{0,8,38},{0,9,172},{0,8,6},{0,8,134},{0,8,70},{0,9,236},
+        {16,7,9},{0,8,94},{0,8,30},{0,9,156},{20,7,99},{0,8,126},{0,8,62},
+        {0,9,220},{18,7,27},{0,8,110},{0,8,46},{0,9,188},{0,8,14},{0,8,142},
+        {0,8,78},{0,9,252},{96,7,0},{0,8,81},{0,8,17},{21,8,131},{18,7,31},
+        {0,8,113},{0,8,49},{0,9,194},{16,7,10},{0,8,97},{0,8,33},{0,9,162},
+        {0,8,1},{0,8,129},{0,8,65},{0,9,226},{16,7,6},{0,8,89},{0,8,25},
+        {0,9,146},{19,7,59},{0,8,121},{0,8,57},{0,9,210},{17,7,17},{0,8,105},
+        {0,8,41},{0,9,178},{0,8,9},{0,8,137},{0,8,73},{0,9,242},{16,7,4},
+        {0,8,85},{0,8,21},{16,8,258},{19,7,43},{0,8,117},{0,8,53},{0,9,202},
+        {17,7,13},{0,8,101},{0,8,37},{0,9,170},{0,8,5},{0,8,133},{0,8,69},
+        {0,9,234},{16,7,8},{0,8,93},{0,8,29},{0,9,154},{20,7,83},{0,8,125},
+        {0,8,61},{0,9,218},{18,7,23},{0,8,109},{0,8,45},{0,9,186},{0,8,13},
+        {0,8,141},{0,8,77},{0,9,250},{16,7,3},{0,8,83},{0,8,19},{21,8,195},
+        {19,7,35},{0,8,115},{0,8,51},{0,9,198},{17,7,11},{0,8,99},{0,8,35},
+        {0,9,166},{0,8,3},{0,8,131},{0,8,67},{0,9,230},{16,7,7},{0,8,91},
+        {0,8,27},{0,9,150},{20,7,67},{0,8,123},{0,8,59},{0,9,214},{18,7,19},
+        {0,8,107},{0,8,43},{0,9,182},{0,8,11},{0,8,139},{0,8,75},{0,9,246},
+        {16,7,5},{0,8,87},{0,8,23},{64,8,0},{19,7,51},{0,8,119},{0,8,55},
+        {0,9,206},{17,7,15},{0,8,103},{0,8,39},{0,9,174},{0,8,7},{0,8,135},
+        {0,8,71},{0,9,238},{16,7,9},{0,8,95},{0,8,31},{0,9,158},{20,7,99},
+        {0,8,127},{0,8,63},{0,9,222},{18,7,27},{0,8,111},{0,8,47},{0,9,190},
+        {0,8,15},{0,8,143},{0,8,79},{0,9,254},{96,7,0},{0,8,80},{0,8,16},
+        {20,8,115},{18,7,31},{0,8,112},{0,8,48},{0,9,193},{16,7,10},{0,8,96},
+        {0,8,32},{0,9,161},{0,8,0},{0,8,128},{0,8,64},{0,9,225},{16,7,6},
+        {0,8,88},{0,8,24},{0,9,145},{19,7,59},{0,8,120},{0,8,56},{0,9,209},
+        {17,7,17},{0,8,104},{0,8,40},{0,9,177},{0,8,8},{0,8,136},{0,8,72},
+        {0,9,241},{16,7,4},{0,8,84},{0,8,20},{21,8,227},{19,7,43},{0,8,116},
+        {0,8,52},{0,9,201},{17,7,13},{0,8,100},{0,8,36},{0,9,169},{0,8,4},
+        {0,8,132},{0,8,68},{0,9,233},{16,7,8},{0,8,92},{0,8,28},{0,9,153},
+        {20,7,83},{0,8,124},{0,8,60},{0,9,217},{18,7,23},{0,8,108},{0,8,44},
+        {0,9,185},{0,8,12},{0,8,140},{0,8,76},{0,9,249},{16,7,3},{0,8,82},
+        {0,8,18},{21,8,163},{19,7,35},{0,8,114},{0,8,50},{0,9,197},{17,7,11},
+        {0,8,98},{0,8,34},{0,9,165},{0,8,2},{0,8,130},{0,8,66},{0,9,229},
+        {16,7,7},{0,8,90},{0,8,26},{0,9,149},{20,7,67},{0,8,122},{0,8,58},
+        {0,9,213},{18,7,19},{0,8,106},{0,8,42},{0,9,181},{0,8,10},{0,8,138},
+        {0,8,74},{0,9,245},{16,7,5},{0,8,86},{0,8,22},{64,8,0},{19,7,51},
+        {0,8,118},{0,8,54},{0,9,205},{17,7,15},{0,8,102},{0,8,38},{0,9,173},
+        {0,8,6},{0,8,134},{0,8,70},{0,9,237},{16,7,9},{0,8,94},{0,8,30},
+        {0,9,157},{20,7,99},{0,8,126},{0,8,62},{0,9,221},{18,7,27},{0,8,110},
+        {0,8,46},{0,9,189},{0,8,14},{0,8,142},{0,8,78},{0,9,253},{96,7,0},
+        {0,8,81},{0,8,17},{21,8,131},{18,7,31},{0,8,113},{0,8,49},{0,9,195},
+        {16,7,10},{0,8,97},{0,8,33},{0,9,163},{0,8,1},{0,8,129},{0,8,65},
+        {0,9,227},{16,7,6},{0,8,89},{0,8,25},{0,9,147},{19,7,59},{0,8,121},
+        {0,8,57},{0,9,211},{17,7,17},{0,8,105},{0,8,41},{0,9,179},{0,8,9},
+        {0,8,137},{0,8,73},{0,9,243},{16,7,4},{0,8,85},{0,8,21},{16,8,258},
+        {19,7,43},{0,8,117},{0,8,53},{0,9,203},{17,7,13},{0,8,101},{0,8,37},
+        {0,9,171},{0,8,5},{0,8,133},{0,8,69},{0,9,235},{16,7,8},{0,8,93},
+        {0,8,29},{0,9,155},{20,7,83},{0,8,125},{0,8,61},{0,9,219},{18,7,23},
+        {0,8,109},{0,8,45},{0,9,187},{0,8,13},{0,8,141},{0,8,77},{0,9,251},
+        {16,7,3},{0,8,83},{0,8,19},{21,8,195},{19,7,35},{0,8,115},{0,8,51},
+        {0,9,199},{17,7,11},{0,8,99},{0,8,35},{0,9,167},{0,8,3},{0,8,131},
+        {0,8,67},{0,9,231},{16,7,7},{0,8,91},{0,8,27},{0,9,151},{20,7,67},
+        {0,8,123},{0,8,59},{0,9,215},{18,7,19},{0,8,107},{0,8,43},{0,9,183},
+        {0,8,11},{0,8,139},{0,8,75},{0,9,247},{16,7,5},{0,8,87},{0,8,23},
+        {64,8,0},{19,7,51},{0,8,119},{0,8,55},{0,9,207},{17,7,15},{0,8,103},
+        {0,8,39},{0,9,175},{0,8,7},{0,8,135},{0,8,71},{0,9,239},{16,7,9},
+        {0,8,95},{0,8,31},{0,9,159},{20,7,99},{0,8,127},{0,8,63},{0,9,223},
+        {18,7,27},{0,8,111},{0,8,47},{0,9,191},{0,8,15},{0,8,143},{0,8,79},
+        {0,9,255}
+    };
+
+    static const code distfix[32] = {
+        {16,5,1},{23,5,257},{19,5,17},{27,5,4097},{17,5,5},{25,5,1025},
+        {21,5,65},{29,5,16385},{16,5,3},{24,5,513},{20,5,33},{28,5,8193},
+        {18,5,9},{26,5,2049},{22,5,129},{64,5,0},{16,5,2},{23,5,385},
+        {19,5,25},{27,5,6145},{17,5,7},{25,5,1537},{21,5,97},{29,5,24577},
+        {16,5,4},{24,5,769},{20,5,49},{28,5,12289},{18,5,13},{26,5,3073},
+        {22,5,193},{64,5,0}
+    };

lib/zlib_inflate/inflate.c

···
-/* inflate.c -- zlib interface to inflate modules
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
+/* inflate.c -- zlib decompression
+ * Copyright (C) 1995-2005 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Based on zlib 1.2.3 but modified for the Linux Kernel by
+ * Richard Purdie <[e-mail]>
+ *
+ * Changes mainly for static instead of dynamic memory allocation
+ *
  */
 
 #include <linux/zutil.h>
-#include "infblock.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
 #include "infutil.h"
 
 int zlib_inflate_workspacesize(void)
 {
-  return sizeof(struct inflate_workspace);
+    return sizeof(struct inflate_workspace);
+}
+
+int zlib_inflateReset(z_streamp strm)
+{
+    struct inflate_state *state;
+
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+    strm->total_in = strm->total_out = state->total = 0;
+    strm->msg = NULL;
+    strm->adler = 1;        /* to support ill-conceived Java test suite */
+    state->mode = HEAD;
+    state->last = 0;
+    state->havedict = 0;
+    state->dmax = 32768U;
+    state->hold = 0;
+    state->bits = 0;
+    state->lencode = state->distcode = state->next = state->codes;
+
+    /* Initialise Window */
+    state->wsize = 1U << state->wbits;
+    state->write = 0;
+    state->whave = 0;
+
+    return Z_OK;
+}
+
+#if 0
+int zlib_inflatePrime(z_streamp strm, int bits, int value)
+{
+    struct inflate_state *state;
+
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+    if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
+    value &= (1L << bits) - 1;
+    state->hold += value << state->bits;
+    state->bits += bits;
+    return Z_OK;
+}
+#endif
+
+int zlib_inflateInit2(z_streamp strm, int windowBits)
+{
+    struct inflate_state *state;
+
+    if (strm == NULL) return Z_STREAM_ERROR;
+    strm->msg = NULL;                 /* in case we return an error */
+
+    state = &WS(strm)->inflate_state;
+    strm->state = (struct internal_state *)state;
+
+    if (windowBits < 0) {
+        state->wrap = 0;
+        windowBits = -windowBits;
+    }
+    else {
+        state->wrap = (windowBits >> 4) + 1;
+    }
+    if (windowBits < 8 || windowBits > 15) {
+        return Z_STREAM_ERROR;
+    }
+    state->wbits = (unsigned)windowBits;
+    state->window = &WS(strm)->working_window[0];
+
+    return zlib_inflateReset(strm);
+}
+
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  This returns fixed tables from inffixed.h.
+ */
+static void zlib_fixedtables(struct inflate_state *state)
+{
+#   include "inffixed.h"
+    state->lencode = lenfix;
+    state->lenbits = 9;
+    state->distcode = distfix;
+    state->distbits = 5;
 }
 
 
-int zlib_inflateReset(
-	z_streamp z
-)
+/*
+   Update the window with the last wsize (normally 32K) bytes written before
+   returning. This is only called when a window is already in use, or when
+   output has been written during this inflate call, but the end of the deflate
+   stream has not been reached yet. It is also called to window dictionary data
+   when a dictionary is loaded.
+
+   Providing output buffers larger than 32K to inflate() should provide a speed
+   advantage, since only the last 32K of output is copied to the sliding window
+   upon return from inflate(), and since all distances after the first 32K of
+   output will fall in the output data, making match copies simpler and faster.
+   The advantage may be dependent on the size of the processor's data caches.
+ */
+static void zlib_updatewindow(z_streamp strm, unsigned out)
 {
-  if (z == NULL || z->state == NULL || z->workspace == NULL)
-    return Z_STREAM_ERROR;
-  z->total_in = z->total_out = 0;
-  z->msg = NULL;
-  z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
-  zlib_inflate_blocks_reset(z->state->blocks, z, NULL);
-  return Z_OK;
-}
+    struct inflate_state *state;
+    unsigned copy, dist;
 
+    state = (struct inflate_state *)strm->state;
 
-int zlib_inflateEnd(
-	z_streamp z
-)
-{
-  if (z == NULL || z->state == NULL || z->workspace == NULL)
-    return Z_STREAM_ERROR;
-  if (z->state->blocks != NULL)
-    zlib_inflate_blocks_free(z->state->blocks, z);
-  z->state = NULL;
-  return Z_OK;
-}
-
-
-int zlib_inflateInit2_(
-	z_streamp z,
-	int w,
-	const char *version,
-	int stream_size
-)
-{
-  if (version == NULL || version[0] != ZLIB_VERSION[0] ||
-      stream_size != sizeof(z_stream) || z->workspace == NULL)
-      return Z_VERSION_ERROR;
-
-  /* initialize state */
-  z->msg = NULL;
-  z->state = &WS(z)->internal_state;
-  z->state->blocks = NULL;
-
-  /* handle undocumented nowrap option (no zlib header or check) */
-  z->state->nowrap = 0;
-  if (w < 0)
-  {
-    w = - w;
-    z->state->nowrap = 1;
-  }
-
-  /* set window size */
-  if (w < 8 || w > 15)
-  {
-    zlib_inflateEnd(z);
-    return Z_STREAM_ERROR;
-  }
-  z->state->wbits = (uInt)w;
-
-  /* create inflate_blocks state */
-  if ((z->state->blocks =
-      zlib_inflate_blocks_new(z, z->state->nowrap ? NULL : zlib_adler32, (uInt)1 << w))
-      == NULL)
-  {
-    zlib_inflateEnd(z);
-    return Z_MEM_ERROR;
-  }
-
-  /* reset state */
-  zlib_inflateReset(z);
-  return Z_OK;
+    /* copy state->wsize or less output bytes into the circular window */
+    copy = out - strm->avail_out;
+    if (copy >= state->wsize) {
+        memcpy(state->window, strm->next_out - state->wsize, state->wsize);
+        state->write = 0;
+        state->whave = state->wsize;
+    }
+    else {
+        dist = state->wsize - state->write;
+        if (dist > copy) dist = copy;
+        memcpy(state->window + state->write, strm->next_out - copy, dist);
+        copy -= dist;
+        if (copy) {
+            memcpy(state->window, strm->next_out - copy, copy);
+            state->write = copy;
+            state->whave = state->wsize;
+        }
+        else {
+            state->write += dist;
+            if (state->write == state->wsize) state->write = 0;
+            if (state->whave < state->wsize) state->whave += dist;
+        }
+    }
 }
 
 
···
  * At the end of a Deflate-compressed PPP packet, we expect to have seen
  * a `stored' block type value but not the (zero) length bytes.
  */
-static int zlib_inflate_packet_flush(inflate_blocks_statef *s)
+/*
+   Returns true if inflate is currently at the end of a block generated by
+   Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+   implementation to provide an additional safety check. PPP uses
+   Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
+   block. When decompressing, PPP checks that at the end of input packet,
+   inflate is waiting for these length bytes.
+ */
+static int zlib_inflateSyncPacket(z_streamp strm)
 {
-    if (s->mode != LENS)
-	return Z_DATA_ERROR;
-    s->mode = TYPE;
+    struct inflate_state *state;
+
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+
+    if (state->mode == STORED && state->bits == 0) {
+	state->mode = TYPE;
+        return Z_OK;
+    }
+    return Z_DATA_ERROR;
+}
+
+/* Macros for inflate(): */
+
+/* check function to use adler32() for zlib or crc32() for gzip */
+#define UPDATE(check, buf, len) zlib_adler32(check, buf, len)
+
+/* Load registers with state in inflate() for speed */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state->hold; \
+        bits = state->bits; \
+    } while (0)
+
+/* Restore state from registers in inflate() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state->hold = hold; \
+        state->bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflate()
+   if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        if (have == 0) goto inf_leave; \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflate(). */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/* Reverse the bytes in a 32-bit value */
+#define REVERSE(q) \
+    ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
+     (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
+
+/*
+   inflate() uses a state machine to process as much input data and generate as
+   much output data as possible before returning.  The state machine is
+   structured roughly as follows:
+
+    for (;;) switch (state) {
+    ...
+    case STATEn:
+        if (not enough input data or output space to make progress)
+            return;
+        ... make progress ...
+        state = STATEm;
+        break;
+    ...
+    }
+
+   so when inflate() is called again, the same case is attempted again, and
+   if the appropriate resources are provided, the machine proceeds to the
+   next state.  The NEEDBITS() macro is usually the way the state evaluates
+   whether it can proceed or should return.  NEEDBITS() does the return if
+   the requested bits are not available.  The typical use of the BITS macros
+   is:
+
+        NEEDBITS(n);
+        ... do something with BITS(n) ...
+        DROPBITS(n);
+
+   where NEEDBITS(n) either returns from inflate() if there isn't enough
+   input left to load n bits into the accumulator, or it continues.  BITS(n)
+   gives the low n bits in the accumulator.  When done, DROPBITS(n) drops
+   the low n bits off the accumulator.  INITBITS() clears the accumulator
+   and sets the number of available bits to zero.  BYTEBITS() discards just
+   enough bits to put the accumulator on a byte boundary.  After BYTEBITS()
+   and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+
+   NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
+   if there is no input available.  The decoding of variable length codes uses
+   PULLBYTE() directly in order to pull just enough bytes to decode the next
+   code, and no more.
+
+   Some states loop until they get enough input, making sure that enough
+   state information is maintained to continue the loop where it left off
+   if NEEDBITS() returns in the loop.  For example, want, need, and keep
+   would all have to actually be part of the saved state in case NEEDBITS()
+   returns:
+
+    case STATEw:
+        while (want < need) {
+            NEEDBITS(n);
+            keep[want++] = BITS(n);
+            DROPBITS(n);
+        }
+        state = STATEx;
+    case STATEx:
+
+   As shown above, if the next state is also the next case, then the break
+   is omitted.
+
+   A state may also return if there is not enough output space available to
+   complete that state.  Those states are copying stored data, writing a
+   literal byte, and copying a matching string.
+
+   When returning, a "goto inf_leave" is used to update the total counters,
+   update the check value, and determine whether any progress has been made
+   during that inflate() call in order to return the proper return code.
+   Progress is defined as a change in either strm->avail_in or strm->avail_out.
+   When there is a window, goto inf_leave will update the window with the last
+   output written.  If a goto inf_leave occurs in the middle of decompression
+   and there is no window currently, goto inf_leave will create one and copy
+   output to the window for the next call of inflate().
+
+   In this implementation, the flush parameter of inflate() only affects the
+   return code (per zlib.h).  inflate() always writes as much as possible to
+   strm->next_out, given the space available and the provided input--the effect
+   documented in zlib.h of Z_SYNC_FLUSH.  Furthermore, inflate() always defers
+   the allocation of and copying into a sliding window until necessary, which
+   provides the effect documented in zlib.h for Z_FINISH when the entire input
+   stream available.  So the only thing the flush parameter actually does is:
+   when flush is set to Z_FINISH, inflate() cannot return Z_OK.  Instead it
+   will return Z_BUF_ERROR if it has not reached the end of the stream.
+ */
+
+int zlib_inflate(z_streamp strm, int flush)
+{
+    struct inflate_state *state;
+    unsigned char *next;    /* next input */
+    unsigned char *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned in, out;           /* save starting available input and output */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char *from;    /* where to copy match bytes from */
+    code this;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    if (strm == NULL || strm->state == NULL || strm->next_out == NULL ||
+        (strm->next_in == NULL && strm->avail_in != 0))
+        return Z_STREAM_ERROR;
+
+    state = (struct inflate_state *)strm->state;
+
+    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
+    LOAD();
+    in = have;
+    out = left;
+    ret = Z_OK;
+    for (;;)
+        switch (state->mode) {
+        case HEAD:
+            if (state->wrap == 0) {
+                state->mode = TYPEDO;
+                break;
+            }
+            NEEDBITS(16);
+            if (
+                ((BITS(8) << 8) + (hold >> 8)) % 31) {
+                strm->msg = (char *)"incorrect header check";
+                state->mode = BAD;
+                break;
+            }
+            if (BITS(4) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state->mode = BAD;
+                break;
+            }
+            DROPBITS(4);
+            len = BITS(4) + 8;
+            if (len > state->wbits) {
+                strm->msg = (char *)"invalid window size";
+                state->mode = BAD;
+                break;
+            }
+            state->dmax = 1U << len;
+            strm->adler = state->check = zlib_adler32(0L, NULL, 0);
+            state->mode = hold & 0x200 ? DICTID : TYPE;
+            INITBITS();
+            break;
+        case DICTID:
+            NEEDBITS(32);
+            strm->adler = state->check = REVERSE(hold);
+            INITBITS();
+            state->mode = DICT;
+        case DICT:
+            if (state->havedict == 0) {
+                RESTORE();
+                return Z_NEED_DICT;
+            }
+            strm->adler = state->check = zlib_adler32(0L, NULL, 0);
+            state->mode = TYPE;
+        case TYPE:
+            if (flush == Z_BLOCK) goto inf_leave;
+        case TYPEDO:
+            if (state->last) {
+                BYTEBITS();
+                state->mode = CHECK;
+                break;
+            }
+            NEEDBITS(3);
+            state->last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                state->mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                zlib_fixedtables(state);
+                state->mode = LEN;              /* decode codes */
+                break;
+            case 2:                             /* dynamic block */
+                state->mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state->mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+        case STORED:
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state->mode = BAD;
+                break;
+            }
+            state->length = (unsigned)hold & 0xffff;
+            INITBITS();
+            state->mode = COPY;
+        case COPY:
+            copy = state->length;
+            if (copy) {
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                if (copy == 0) goto inf_leave;
+                memcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state->length -= copy;
+                break;
+            }
+            state->mode = TYPE;
+            break;
+        case TABLE:
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state->nlen > 286 || state->ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            state->have = 0;
+            state->mode = LENLENS;
+        case LENLENS:
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            state->lencode = (code const *)(state->next);
+            state->lenbits = 7;
+            ret = zlib_inflate_table(CODES, state->lens, 19, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->have = 0;
+            state->mode = CODELENS;
+        case CODELENS:
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    this = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (this.val < 16) {
+                    NEEDBITS(this.bits);
+                    DROPBITS(this.bits);
+                    state->lens[state->have++] = this.val;
+                }
+                else {
+                    if (this.val == 16) {
+                        NEEDBITS(this.bits + 2);
+                        DROPBITS(this.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state->mode = BAD;
+                            break;
+                        }
+                        len = state->lens[state->have - 1];
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (this.val == 17) {
+                        NEEDBITS(this.bits + 3);
+                        DROPBITS(this.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(this.bits + 7);
+                        DROPBITS(this.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state->mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state->mode == BAD) break;
+
+            /* build code tables */
+            state->next = state->codes;
+            state->lencode = (code const *)(state->next);
+            state->lenbits = 9;
+            ret = zlib_inflate_table(LENS, state->lens, state->nlen, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->distcode = (code const *)(state->next);
+            state->distbits = 6;
+            ret = zlib_inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+                            &(state->next), &(state->distbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state->mode = BAD;
+                break;
+            }
+            state->mode = LEN;
+        case LEN:
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                inflate_fast(strm, out);
+                LOAD();
+                break;
+            }
+            for (;;) {
+                this = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(this.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (this.op && (this.op & 0xf0) == 0) {
+                last = this;
+                for (;;) {
+                    this = state->lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(this.bits);
+            state->length = (unsigned)this.val;
+            if ((int)(this.op) == 0) {
+                state->mode = LIT;
+                break;
+            }
+            if (this.op & 32) {
+                state->mode = TYPE;
+                break;
+            }
+            if (this.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state->mode = BAD;
+                break;
+            }
+            state->extra = (unsigned)(this.op) & 15;
+            state->mode = LENEXT;
+        case LENEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->length += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+            state->mode = DIST;
+        case DIST:
+            for (;;) {
+                this = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(this.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((this.op & 0xf0) == 0) {
+                last = this;
+                for (;;) {
+                    this = state->distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(this.bits);
+            if (this.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+            state->offset = (unsigned)this.val;
+            state->extra = (unsigned)(this.op) & 15;
+            state->mode = DISTEXT;
+        case DISTEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->offset += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+#ifdef INFLATE_STRICT
+            if (state->offset > state->dmax) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            if (state->offset > state->whave + out - left) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+            state->mode = MATCH;
+        case MATCH:
+            if (left == 0) goto inf_leave;
+            copy = out - left;
+            if (state->offset > copy) {         /* copy from window */
+                copy = state->offset - copy;
+                if (copy > state->write) {
+                    copy -= state->write;
+                    from = state->window + (state->wsize - copy);
+                }
+                else
+                    from = state->window + (state->write - copy);
+                if (copy > state->length) copy = state->length;
+            }
+            else {                              /* copy from output */
+                from = put - state->offset;
+                copy = state->length;
+            }
+            if (copy > left) copy = left;
+            left -= copy;
+            state->length -= copy;
+            do {
+                *put++ = *from++;
+            } while (--copy);
+            if (state->length == 0) state->mode = LEN;
+            break;
+        case LIT:
+            if (left == 0) goto inf_leave;
+            *put++ = (unsigned char)(state->length);
+            left--;
+            state->mode = LEN;
+            break;
+        case CHECK:
+            if (state->wrap) {
+                NEEDBITS(32);
+                out -= left;
+                strm->total_out += out;
+                state->total += out;
+                if (out)
+                    strm->adler = state->check =
+                        UPDATE(state->check, put - out, out);
+                out = left;
+                if ((
+                     REVERSE(hold)) != state->check) {
+                    strm->msg = (char *)"incorrect data check";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+            }
+            state->mode = DONE;
+        case DONE:
+            ret = Z_STREAM_END;
+            goto inf_leave;
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+        case MEM:
+            return Z_MEM_ERROR;
+        case SYNC:
+        default:
+            return Z_STREAM_ERROR;
+        }
+
+    /*
+       Return from inflate(), updating the total counts and the check value.
+       If there was no progress during the inflate() call, return a buffer
+       error.  Call zlib_updatewindow() to create and/or update the window state.
+     */
+  inf_leave:
+    RESTORE();
+    if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
+        zlib_updatewindow(strm, out);
+
+    in -= strm->avail_in;
+    out -= strm->avail_out;
+    strm->total_in += in;
+    strm->total_out += out;
+    state->total += out;
+    if (state->wrap && out)
+        strm->adler = state->check =
+            UPDATE(state->check, strm->next_out - out, out);
+
+    strm->data_type = state->bits + (state->last ? 64 : 0) +
+                      (state->mode == TYPE ? 128 : 0);
+    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
+        ret = Z_BUF_ERROR;
+
+    if (flush == Z_PACKET_FLUSH && ret == Z_OK &&
+            (strm->avail_out != 0 || strm->avail_in == 0))
+		return zlib_inflateSyncPacket(strm);
+    return ret;
+}
+
+int zlib_inflateEnd(z_streamp strm)
+{
+    if (strm == NULL || strm->state == NULL)
+        return Z_STREAM_ERROR;
     return Z_OK;
 }
 
-
-int zlib_inflateInit_(
-	z_streamp z,
-	const char *version,
-	int stream_size
-)
+#if 0
+int zlib_inflateSetDictionary(z_streamp strm, const Byte *dictionary,
+        uInt dictLength)
 {
-  return zlib_inflateInit2_(z, DEF_WBITS, version, stream_size);
+    struct inflate_state *state;
+    unsigned long id;
+
+    /* check state */
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+    if (state->wrap != 0 && state->mode != DICT)
+        return Z_STREAM_ERROR;
+
+    /* check for correct dictionary id */
+    if (state->mode == DICT) {
+        id = zlib_adler32(0L, NULL, 0);
+        id = zlib_adler32(id, dictionary, dictLength);
+        if (id != state->check)
+            return Z_DATA_ERROR;
+    }
+
+    /* copy dictionary to window */
+    zlib_updatewindow(strm, strm->avail_out);
+
+    if (dictLength > state->wsize) {
+        memcpy(state->window, dictionary + dictLength - state->wsize,
+                state->wsize);
+        state->whave = state->wsize;
+    }
+    else {
+        memcpy(state->window + state->wsize - dictLength, dictionary,
+                dictLength);
+        state->whave = dictLength;
+    }
+    state->havedict = 1;
+    return Z_OK;
 }
+#endif
 
-#undef NEEDBYTE
-#undef NEXTBYTE
-#define NEEDBYTE {if(z->avail_in==0)goto empty;r=trv;}
-#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
-
-int zlib_inflate(
-	z_streamp z,
-	int f
-)
+#if 0
+/*
+   Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff.  Return when found
+   or when out of input.  When called, *have is the number of pattern bytes
+   found in order so far, in 0..3.  On return *have is updated to the new
+   state.  If on return *have equals four, then the pattern was found and the
+   return value is how many bytes were read including the last byte of the
+   pattern.  If *have is less than four, then the pattern has not been found
+   yet and the return value is len.  In the latter case, zlib_syncsearch() can be
+   called again with more data and the *have state.  *have is initialized to
+   zero for the first call.
+ */
+static unsigned zlib_syncsearch(unsigned *have, unsigned char *buf,
+        unsigned len)
 {
-  int r, trv;
-  uInt b;
+    unsigned got;
+    unsigned next;
 
-  if (z == NULL || z->state == NULL || z->next_in == NULL)
-    return Z_STREAM_ERROR;
-  trv = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
-  r = Z_BUF_ERROR;
-  while (1) switch (z->state->mode)
-  {
-    case METHOD:
-      NEEDBYTE
-      if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
-      {
-        z->state->mode = I_BAD;
-        z->msg = (char*)"unknown compression method";
-        z->state->sub.marker = 5;       /* can't try inflateSync */
-        break;
-      }
-      if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
-      {
-        z->state->mode = I_BAD;
-        z->msg = (char*)"invalid window size";
-        z->state->sub.marker = 5;       /* can't try inflateSync */
-        break;
-      }
-      z->state->mode = FLAG;
-    case FLAG:
-      NEEDBYTE
-      b = NEXTBYTE;
-      if (((z->state->sub.method << 8) + b) % 31)
-      {
-        z->state->mode = I_BAD;
-        z->msg = (char*)"incorrect header check";
-        z->state->sub.marker = 5;       /* can't try inflateSync */
-        break;
-      }
-      if (!(b & PRESET_DICT))
-      {
-        z->state->mode = BLOCKS;
-        break;
-      }
-      z->state->mode = DICT4;
-    case DICT4:
-      NEEDBYTE
-      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
-      z->state->mode = DICT3;
-    case DICT3:
-      NEEDBYTE
-      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
-      z->state->mode = DICT2;
-    case DICT2:
-      NEEDBYTE
-      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
-      z->state->mode = DICT1;
-    case DICT1:
-      NEEDBYTE
-      z->state->sub.check.need += (uLong)NEXTBYTE;
-      z->adler = z->state->sub.check.need;
-      z->state->mode = DICT0;
-      return Z_NEED_DICT;
-    case DICT0:
-      z->state->mode = I_BAD;
-      z->msg = (char*)"need dictionary";
-      z->state->sub.marker = 0;       /* can try inflateSync */
-      return Z_STREAM_ERROR;
-    case BLOCKS:
-      r = zlib_inflate_blocks(z->state->blocks, z, r);
-      if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
-	  r = zlib_inflate_packet_flush(z->state->blocks);
-      if (r == Z_DATA_ERROR)
-      {
-        z->state->mode = I_BAD;
-        z->state->sub.marker = 0;       /* can try inflateSync */
-        break;
-      }
-      if (r == Z_OK)
-        r = trv;
-      if (r != Z_STREAM_END)
-        return r;
-      r = trv;
-      zlib_inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
-      if (z->state->nowrap)
-      {
-        z->state->mode = I_DONE;
-        break;
-      }
-      z->state->mode = CHECK4;
-    case CHECK4:
-      NEEDBYTE
-      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
-      z->state->mode = CHECK3;
-    case CHECK3:
-      NEEDBYTE
-      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
-      z->state->mode = CHECK2;
-    case CHECK2:
-      NEEDBYTE
-      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
-      z->state->mode = CHECK1;
-    case CHECK1:
-      NEEDBYTE
-      z->state->sub.check.need += (uLong)NEXTBYTE;
+    got = *have;
+    next = 0;
+    while (next < len && got < 4) {
+        if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
+            got++;
+        else if (buf[next])
+            got = 0;
+        else
+            got = 4 - got;
+        next++;
+    }
+    *have = got;
+    return next;
+}
+#endif
 
-      if (z->state->sub.check.was != z->state->sub.check.need)
-      {
-        z->state->mode = I_BAD;
-        z->msg = (char*)"incorrect data check";
-        z->state->sub.marker = 5;       /* can't try inflateSync */
-        break;
-      }
-      z->state->mode = I_DONE;
-    case I_DONE:
-      return Z_STREAM_END;
-    case I_BAD:
-      return Z_DATA_ERROR;
-    default:
-      return Z_STREAM_ERROR;
-  }
- empty:
-  if (f != Z_PACKET_FLUSH)
-    return r;
-  z->state->mode = I_BAD;
-  z->msg = (char *)"need more for packet flush";
-  z->state->sub.marker = 0;       /* can try inflateSync */
-  return Z_DATA_ERROR;
+#if 0
+int zlib_inflateSync(z_streamp strm)
+{
+    unsigned len;               /* number of bytes to look at or looked at */
+    unsigned long in, out;      /* temporary to save total_in and total_out */
+    unsigned char buf[4];       /* to restore bit buffer to byte string */
+    struct inflate_state *state;
+
+    /* check parameters */
+    if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR;
+    state = (struct inflate_state *)strm->state;
+    if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
+
+    /* if first time, start search in bit buffer */
+    if (state->mode != SYNC) {
+        state->mode = SYNC;
+        state->hold <<= state->bits & 7;
+        state->bits -= state->bits & 7;
+        len = 0;
+        while (state->bits >= 8) {
+            buf[len++] = (unsigned char)(state->hold);
+            state->hold >>= 8;
+            state->bits -= 8;
+        }
+        state->have = 0;
+        zlib_syncsearch(&(state->have), buf, len);
+    }
+
+    /* search available input */
+    len = zlib_syncsearch(&(state->have), strm->next_in, strm->avail_in);
+    strm->avail_in -= len;
+    strm->next_in += len;
+    strm->total_in += len;
+
+    /* return no joy or set up to restart inflate() on a new block */
+    if (state->have != 4) return Z_DATA_ERROR;
+    in = strm->total_in;  out = strm->total_out;
+    zlib_inflateReset(strm);
+    strm->total_in = in;  strm->total_out = out;
+    state->mode = TYPE;
+    return Z_OK;
+}
+#endif
+
+/*
+ * This subroutine adds the data at next_in/avail_in to the output history
+ * without performing any output.  The output buffer must be "caught up";
+ * i.e. no pending output but this should always be the case. The state must
+ * be waiting on the start of a block (i.e. mode == TYPE or HEAD).  On exit,
+ * the output will also be caught up, and the checksum will have been updated
+ * if need be.
+ */
+int zlib_inflateIncomp(z_stream *z)
+{
+    struct inflate_state *state = (struct inflate_state *)z->state;
+    Byte *saved_no = z->next_out;
+    uInt saved_ao = z->avail_out;
+
+    if (state->mode != TYPE && state->mode != HEAD)
+	return Z_DATA_ERROR;
+
+    /* Setup some variables to allow misuse of updateWindow */
+    z->avail_out = 0;
+    z->next_out = z->next_in + z->avail_in;
+
+    zlib_updatewindow(z, z->avail_in);
+
+    /* Restore saved variables */
+    z->avail_out = saved_ao;
+    z->next_out = saved_no;
+
+    z->adler = state->check =
+        UPDATE(state->check, z->next_in, z->avail_in);
+
+    z->total_out += z->avail_in;
+    z->total_in += z->avail_in;
+    z->next_in += z->avail_in;
+    state->total += z->avail_in;
+    z->avail_in = 0;
+
+    return Z_OK;
 }

lib/zlib_inflate/inflate.h

···
+/* inflate.h -- internal inflate state definition
+ * Copyright (C) 1995-2004 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Possible inflate modes between inflate() calls */
+typedef enum {
+    HEAD,       /* i: waiting for magic header */
+    FLAGS,      /* i: waiting for method and flags (gzip) */
+    TIME,       /* i: waiting for modification time (gzip) */
+    OS,         /* i: waiting for extra flags and operating system (gzip) */
+    EXLEN,      /* i: waiting for extra length (gzip) */
+    EXTRA,      /* i: waiting for extra bytes (gzip) */
+    NAME,       /* i: waiting for end of file name (gzip) */
+    COMMENT,    /* i: waiting for end of comment (gzip) */
+    HCRC,       /* i: waiting for header crc (gzip) */
+    DICTID,     /* i: waiting for dictionary check value */
+    DICT,       /* waiting for inflateSetDictionary() call */
+        TYPE,       /* i: waiting for type bits, including last-flag bit */
+        TYPEDO,     /* i: same, but skip check to exit inflate on new block */
+        STORED,     /* i: waiting for stored size (length and complement) */
+        COPY,       /* i/o: waiting for input or output to copy stored block */
+        TABLE,      /* i: waiting for dynamic block table lengths */
+        LENLENS,    /* i: waiting for code length code lengths */
+        CODELENS,   /* i: waiting for length/lit and distance code lengths */
+            LEN,        /* i: waiting for length/lit code */
+            LENEXT,     /* i: waiting for length extra bits */
+            DIST,       /* i: waiting for distance code */
+            DISTEXT,    /* i: waiting for distance extra bits */
+            MATCH,      /* o: waiting for output space to copy string */
+            LIT,        /* o: waiting for output space to write literal */
+    CHECK,      /* i: waiting for 32-bit check value */
+    LENGTH,     /* i: waiting for 32-bit length (gzip) */
+    DONE,       /* finished check, done -- remain here until reset */
+    BAD,        /* got a data error -- remain here until reset */
+    MEM,        /* got an inflate() memory error -- remain here until reset */
+    SYNC        /* looking for synchronization bytes to restart inflate() */
+} inflate_mode;
+
+/*
+    State transitions between above modes -
+
+    (most modes can go to the BAD or MEM mode -- not shown for clarity)
+
+    Process header:
+        HEAD -> (gzip) or (zlib)
+        (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME
+        NAME -> COMMENT -> HCRC -> TYPE
+        (zlib) -> DICTID or TYPE
+        DICTID -> DICT -> TYPE
+    Read deflate blocks:
+            TYPE -> STORED or TABLE or LEN or CHECK
+            STORED -> COPY -> TYPE
+            TABLE -> LENLENS -> CODELENS -> LEN
+    Read deflate codes:
+                LEN -> LENEXT or LIT or TYPE
+                LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
+                LIT -> LEN
+    Process trailer:
+        CHECK -> LENGTH -> DONE
+ */
+
+/* state maintained between inflate() calls.  Approximately 7K bytes. */
+struct inflate_state {
+    inflate_mode mode;          /* current inflate mode */
+    int last;                   /* true if processing last block */
+    int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip */
+    int havedict;               /* true if dictionary provided */
+    int flags;                  /* gzip header method and flags (0 if zlib) */
+    unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
+    unsigned long check;        /* protected copy of check value */
+    unsigned long total;        /* protected copy of output count */
+ /*   gz_headerp head; */           /* where to save gzip header information */
+        /* sliding window */
+    unsigned wbits;             /* log base 2 of requested window size */
+    unsigned wsize;             /* window size or zero if not using window */
+    unsigned whave;             /* valid bytes in the window */
+    unsigned write;             /* window write index */
+    unsigned char *window;  /* allocated sliding window, if needed */
+        /* bit accumulator */
+    unsigned long hold;         /* input bit accumulator */
+    unsigned bits;              /* number of bits in "in" */
+        /* for string and stored block copying */
+    unsigned length;            /* literal or length of data to copy */
+    unsigned offset;            /* distance back to copy string from */
+        /* for table and code decoding */
+    unsigned extra;             /* extra bits needed */
+        /* fixed and dynamic code tables */
+    code const *lencode;    /* starting table for length/literal codes */
+    code const *distcode;   /* starting table for distance codes */
+    unsigned lenbits;           /* index bits for lencode */
+    unsigned distbits;          /* index bits for distcode */
+        /* dynamic table building */
+    unsigned ncode;             /* number of code length code lengths */
+    unsigned nlen;              /* number of length code lengths */
+    unsigned ndist;             /* number of distance code lengths */
+    unsigned have;              /* number of code lengths in lens[] */
+    code *next;             /* next available space in codes[] */
+    unsigned short lens[320];   /* temporary storage for code lengths */
+    unsigned short work[288];   /* work area for code table building */
+    code codes[ENOUGH];         /* space for code tables */
+};

lib/zlib_inflate/inflate_syms.c

···
 
 EXPORT_SYMBOL(zlib_inflate_workspacesize);
 EXPORT_SYMBOL(zlib_inflate);
-EXPORT_SYMBOL(zlib_inflateInit_);
-EXPORT_SYMBOL(zlib_inflateInit2_);
+EXPORT_SYMBOL(zlib_inflateInit2);
 EXPORT_SYMBOL(zlib_inflateEnd);
 EXPORT_SYMBOL(zlib_inflateReset);
 EXPORT_SYMBOL(zlib_inflateIncomp); 

lib/zlib_inflate/inflate_sync.c

···
-/* inflate.c -- zlib interface to inflate modules
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
-
-#include <linux/zutil.h>
-#include "infblock.h"
-#include "infutil.h"
-
-#if 0
-int zlib_inflateSync(
-	z_streamp z
-)
-{
-  uInt n;       /* number of bytes to look at */
-  Byte *p;      /* pointer to bytes */
-  uInt m;       /* number of marker bytes found in a row */
-  uLong r, w;   /* temporaries to save total_in and total_out */
-
-  /* set up */
-  if (z == NULL || z->state == NULL)
-    return Z_STREAM_ERROR;
-  if (z->state->mode != I_BAD)
-  {
-    z->state->mode = I_BAD;
-    z->state->sub.marker = 0;
-  }
-  if ((n = z->avail_in) == 0)
-    return Z_BUF_ERROR;
-  p = z->next_in;
-  m = z->state->sub.marker;
-
-  /* search */
-  while (n && m < 4)
-  {
-    static const Byte mark[4] = {0, 0, 0xff, 0xff};
-    if (*p == mark[m])
-      m++;
-    else if (*p)
-      m = 0;
-    else
-      m = 4 - m;
-    p++, n--;
-  }
-
-  /* restore */
-  z->total_in += p - z->next_in;
-  z->next_in = p;
-  z->avail_in = n;
-  z->state->sub.marker = m;
-
-  /* return no joy or set up to restart on a new block */
-  if (m != 4)
-    return Z_DATA_ERROR;
-  r = z->total_in;  w = z->total_out;
-  zlib_inflateReset(z);
-  z->total_in = r;  z->total_out = w;
-  z->state->mode = BLOCKS;
-  return Z_OK;
-}
-#endif  /*  0  */
-
-
-/* Returns true if inflate is currently at the end of a block generated
- * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
- * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
- * but removes the length bytes of the resulting empty stored block. When
- * decompressing, PPP checks that at the end of input packet, inflate is
- * waiting for these length bytes.
- */
-#if 0
-int zlib_inflateSyncPoint(
-	z_streamp z
-)
-{
-  if (z == NULL || z->state == NULL || z->state->blocks == NULL)
-    return Z_STREAM_ERROR;
-  return zlib_inflate_blocks_sync_point(z->state->blocks);
-}
-#endif  /*  0  */
-
-/*
- * This subroutine adds the data at next_in/avail_in to the output history
- * without performing any output.  The output buffer must be "caught up";
- * i.e. no pending output (hence s->read equals s->write), and the state must
- * be BLOCKS (i.e. we should be willing to see the start of a series of
- * BLOCKS).  On exit, the output will also be caught up, and the checksum
- * will have been updated if need be.
- */
-static int zlib_inflate_addhistory(inflate_blocks_statef *s,
-				      z_stream              *z)
-{
-    uLong b;              /* bit buffer */  /* NOT USED HERE */
-    uInt k;               /* bits in bit buffer */ /* NOT USED HERE */
-    uInt t;               /* temporary storage */
-    Byte *p;              /* input data pointer */
-    uInt n;               /* bytes available there */
-    Byte *q;              /* output window write pointer */
-    uInt m;               /* bytes to end of window or read pointer */
-
-    if (s->read != s->write)
-	return Z_STREAM_ERROR;
-    if (s->mode != TYPE)
-	return Z_DATA_ERROR;
-
-    /* we're ready to rock */
-    LOAD
-    /* while there is input ready, copy to output buffer, moving
-     * pointers as needed.
-     */
-    while (n) {
-	t = n;  /* how many to do */
-	/* is there room until end of buffer? */
-	if (t > m) t = m;
-	/* update check information */
-	if (s->checkfn != NULL)
-	    s->check = (*s->checkfn)(s->check, q, t);
-	memcpy(q, p, t);
-	q += t;
-	p += t;
-	n -= t;
-	z->total_out += t;
-	s->read = q;    /* drag read pointer forward */
-/*      WWRAP  */ 	/* expand WWRAP macro by hand to handle s->read */
-	if (q == s->end) {
-	    s->read = q = s->window;
-	    m = WAVAIL;
-	}
-    }
-    UPDATE
-    return Z_OK;
-}
-
-
-/*
- * This subroutine adds the data at next_in/avail_in to the output history
- * without performing any output.  The output buffer must be "caught up";
- * i.e. no pending output (hence s->read equals s->write), and the state must
- * be BLOCKS (i.e. we should be willing to see the start of a series of
- * BLOCKS).  On exit, the output will also be caught up, and the checksum
- * will have been updated if need be.
- */
-
-int zlib_inflateIncomp(
-	z_stream *z
-
-)
-{
-    if (z->state->mode != BLOCKS)
-	return Z_DATA_ERROR;
-    return zlib_inflate_addhistory(z->state->blocks, z);
-}

lib/zlib_inflate/inftrees.c

···
 /* inftrees.c -- generate Huffman trees for efficient decoding
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
+ * Copyright (C) 1995-2005 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 #include <linux/zutil.h>
 #include "inftrees.h"
-#include "infutil.h"
 
-static const char inflate_copyright[] __attribute_used__ =
-   " inflate 1.1.3 Copyright 1995-1998 Mark Adler ";
+#define MAXBITS 15
+
+const char inflate_copyright[] =
+   " inflate 1.2.3 Copyright 1995-2005 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.
  */
-struct internal_state;
-
-/* simplify the use of the inflate_huft type with some defines */
-#define exop word.what.Exop
-#define bits word.what.Bits
-
-
-static int huft_build (
-    uInt *,             /* code lengths in bits */
-    uInt,               /* number of codes */
-    uInt,               /* number of "simple" codes */
-    const uInt *,       /* list of base values for non-simple codes */
-    const uInt *,       /* list of extra bits for non-simple codes */
-    inflate_huft **,    /* result: starting table */
-    uInt *,             /* maximum lookup bits (returns actual) */
-    inflate_huft *,     /* space for trees */
-    uInt *,             /* hufts used in space */
-    uInt * );           /* space for values */
-
-/* Tables for deflate from PKZIP's appnote.txt. */
-static const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
-        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
-        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
-        /* see note #13 above about 258 */
-static const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
-        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
-        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
-static const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
-        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
-        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
-        8193, 12289, 16385, 24577};
-static const uInt cpdext[30] = { /* Extra bits for distance codes */
-        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
-        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
-        12, 12, 13, 13};
 
 /*
-   Huffman code decoding is performed using a multi-level table lookup.
-   The fastest way to decode is to simply build a lookup table whose
-   size is determined by the longest code.  However, the time it takes
-   to build this table can also be a factor if the data being decoded
-   is not very long.  The most common codes are necessarily the
-   shortest codes, so those codes dominate the decoding time, and hence
-   the speed.  The idea is you can have a shorter table that decodes the
-   shorter, more probable codes, and then point to subsidiary tables for
-   the longer codes.  The time it costs to decode the longer codes is
-   then traded against the time it takes to make longer tables.
-
-   This results of this trade are in the variables lbits and dbits
-   below.  lbits is the number of bits the first level table for literal/
-   length codes can decode in one step, and dbits is the same thing for
-   the distance codes.  Subsequent tables are also less than or equal to
-   those sizes.  These values may be adjusted either when all of the
-   codes are shorter than that, in which case the longest code length in
-   bits is used, or when the shortest code is *longer* than the requested
-   table size, in which case the length of the shortest code in bits is
-   used.
-
-   There are two different values for the two tables, since they code a
-   different number of possibilities each.  The literal/length table
-   codes 286 possible values, or in a flat code, a little over eight
-   bits.  The distance table codes 30 possible values, or a little less
-   than five bits, flat.  The optimum values for speed end up being
-   about one bit more than those, so lbits is 8+1 and dbits is 5+1.
-   The optimum values may differ though from machine to machine, and
-   possibly even between compilers.  Your mileage may vary.
+   Build a set of tables to decode the provided canonical Huffman code.
+   The code lengths are lens[0..codes-1].  The result starts at *table,
+   whose indices are 0..2^bits-1.  work is a writable array of at least
+   lens shorts, which is used as a work area.  type is the type of code
+   to be generated, CODES, LENS, or DISTS.  On return, zero is success,
+   -1 is an invalid code, and +1 means that ENOUGH isn't enough.  table
+   on return points to the next available entry's address.  bits is the
+   requested root table index bits, and on return it is the actual root
+   table index bits.  It will differ if the request is greater than the
+   longest code or if it is less than the shortest code.
  */
-
-
-/* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
-#define BMAX 15         /* maximum bit length of any code */
-
-static int huft_build(
-	uInt *b,               /* code lengths in bits (all assumed <= BMAX) */
-	uInt n,                /* number of codes (assumed <= 288) */
-	uInt s,                /* number of simple-valued codes (0..s-1) */
-	const uInt *d,         /* list of base values for non-simple codes */
-	const uInt *e,         /* list of extra bits for non-simple codes */
-	inflate_huft **t,      /* result: starting table */
-	uInt *m,               /* maximum lookup bits, returns actual */
-	inflate_huft *hp,      /* space for trees */
-	uInt *hn,              /* hufts used in space */
-	uInt *v                /* working area: values in order of bit length */
-)
-/* Given a list of code lengths and a maximum table size, make a set of
-   tables to decode that set of codes.  Return Z_OK on success, Z_BUF_ERROR
-   if the given code set is incomplete (the tables are still built in this
-   case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
-   lengths), or Z_MEM_ERROR if not enough memory. */
+int zlib_inflate_table(type, lens, codes, table, bits, work)
+codetype type;
+unsigned short *lens;
+unsigned codes;
+code **table;
+unsigned *bits;
+unsigned short *work;
 {
+    unsigned len;               /* a code's length in bits */
+    unsigned sym;               /* index of code symbols */
+    unsigned min, max;          /* minimum and maximum code lengths */
+    unsigned root;              /* number of index bits for root table */
+    unsigned curr;              /* number of index bits for current table */
+    unsigned drop;              /* code bits to drop for sub-table */
+    int left;                   /* number of prefix codes available */
+    unsigned used;              /* code entries in table used */
+    unsigned huff;              /* Huffman code */
+    unsigned incr;              /* for incrementing code, index */
+    unsigned fill;              /* index for replicating entries */
+    unsigned low;               /* low bits for current root entry */
+    unsigned mask;              /* mask for low root bits */
+    code this;                  /* table entry for duplication */
+    code *next;             /* next available space in table */
+    const unsigned short *base;     /* base value table to use */
+    const unsigned short *extra;    /* extra bits table to use */
+    int end;                    /* use base and extra for symbol > end */
+    unsigned short count[MAXBITS+1];    /* number of codes of each length */
+    unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
+    static const unsigned short lbase[31] = { /* Length codes 257..285 base */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
+    static const unsigned short lext[31] = { /* Length codes 257..285 extra */
+        16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
+        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 201, 196};
+    static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+        8193, 12289, 16385, 24577, 0, 0};
+    static const unsigned short dext[32] = { /* Distance codes 0..29 extra */
+        16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22,
+        23, 23, 24, 24, 25, 25, 26, 26, 27, 27,
+        28, 28, 29, 29, 64, 64};
 
-  uInt a;                       /* counter for codes of length k */
-  uInt c[BMAX+1];               /* bit length count table */
-  uInt f;                       /* i repeats in table every f entries */
-  int g;                        /* maximum code length */
-  int h;                        /* table level */
-  register uInt i;              /* counter, current code */
-  register uInt j;              /* counter */
-  register int k;               /* number of bits in current code */
-  int l;                        /* bits per table (returned in m) */
-  uInt mask;                    /* (1 << w) - 1, to avoid cc -O bug on HP */
-  register uInt *p;             /* pointer into c[], b[], or v[] */
-  inflate_huft *q;              /* points to current table */
-  struct inflate_huft_s r;      /* table entry for structure assignment */
-  inflate_huft *u[BMAX];        /* table stack */
-  register int w;               /* bits before this table == (l * h) */
-  uInt x[BMAX+1];               /* bit offsets, then code stack */
-  uInt *xp;                     /* pointer into x */
-  int y;                        /* number of dummy codes added */
-  uInt z;                       /* number of entries in current table */
+    /*
+       Process a set of code lengths to create a canonical Huffman code.  The
+       code lengths are lens[0..codes-1].  Each length corresponds to the
+       symbols 0..codes-1.  The Huffman code is generated by first sorting the
+       symbols by length from short to long, and retaining the symbol order
+       for codes with equal lengths.  Then the code starts with all zero bits
+       for the first code of the shortest length, and the codes are integer
+       increments for the same length, and zeros are appended as the length
+       increases.  For the deflate format, these bits are stored backwards
+       from their more natural integer increment ordering, and so when the
+       decoding tables are built in the large loop below, the integer codes
+       are incremented backwards.
 
+       This routine assumes, but does not check, that all of the entries in
+       lens[] are in the range 0..MAXBITS.  The caller must assure this.
+       1..MAXBITS is interpreted as that code length.  zero means that that
+       symbol does not occur in this code.
 
-  /* Generate counts for each bit length */
-  p = c;
-#define C0 *p++ = 0;
-#define C2 C0 C0 C0 C0
-#define C4 C2 C2 C2 C2
-  C4                            /* clear c[]--assume BMAX+1 is 16 */
-  p = b;  i = n;
-  do {
-    c[*p++]++;                  /* assume all entries <= BMAX */
-  } while (--i);
-  if (c[0] == n)                /* null input--all zero length codes */
-  {
-    *t = NULL;
-    *m = 0;
-    return Z_OK;
-  }
+       The codes are sorted by computing a count of codes for each length,
+       creating from that a table of starting indices for each length in the
+       sorted table, and then entering the symbols in order in the sorted
+       table.  The sorted table is work[], with that space being provided by
+       the caller.
 
+       The length counts are used for other purposes as well, i.e. finding
+       the minimum and maximum length codes, determining if there are any
+       codes at all, checking for a valid set of lengths, and looking ahead
+       at length counts to determine sub-table sizes when building the
+       decoding tables.
+     */
 
-  /* Find minimum and maximum length, bound *m by those */
-  l = *m;
-  for (j = 1; j <= BMAX; j++)
-    if (c[j])
-      break;
-  k = j;                        /* minimum code length */
-  if ((uInt)l < j)
-    l = j;
-  for (i = BMAX; i; i--)
-    if (c[i])
-      break;
-  g = i;                        /* maximum code length */
-  if ((uInt)l > i)
-    l = i;
-  *m = l;
+    /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */
+    for (len = 0; len <= MAXBITS; len++)
+        count[len] = 0;
+    for (sym = 0; sym < codes; sym++)
+        count[lens[sym]]++;
 
+    /* bound code lengths, force root to be within code lengths */
+    root = *bits;
+    for (max = MAXBITS; max >= 1; max--)
+        if (count[max] != 0) break;
+    if (root > max) root = max;
+    if (max == 0) {                     /* no symbols to code at all */
+        this.op = (unsigned char)64;    /* invalid code marker */
+        this.bits = (unsigned char)1;
+        this.val = (unsigned short)0;
+        *(*table)++ = this;             /* make a table to force an error */
+        *(*table)++ = this;
+        *bits = 1;
+        return 0;     /* no symbols, but wait for decoding to report error */
+    }
+    for (min = 1; min <= MAXBITS; min++)
+        if (count[min] != 0) break;
+    if (root < min) root = min;
 
-  /* Adjust last length count to fill out codes, if needed */
-  for (y = 1 << j; j < i; j++, y <<= 1)
-    if ((y -= c[j]) < 0)
-      return Z_DATA_ERROR;
-  if ((y -= c[i]) < 0)
-    return Z_DATA_ERROR;
-  c[i] += y;
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;
+        left -= count[len];
+        if (left < 0) return -1;        /* over-subscribed */
+    }
+    if (left > 0 && (type == CODES || max != 1))
+        return -1;                      /* incomplete set */
 
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + count[len];
 
-  /* Generate starting offsets into the value table for each length */
-  x[1] = j = 0;
-  p = c + 1;  xp = x + 2;
-  while (--i) {                 /* note that i == g from above */
-    *xp++ = (j += *p++);
-  }
+    /* sort symbols by length, by symbol order within each length */
+    for (sym = 0; sym < codes; sym++)
+        if (lens[sym] != 0) work[offs[lens[sym]]++] = (unsigned short)sym;
 
+    /*
+       Create and fill in decoding tables.  In this loop, the table being
+       filled is at next and has curr index bits.  The code being used is huff
+       with length len.  That code is converted to an index by dropping drop
+       bits off of the bottom.  For codes where len is less than drop + curr,
+       those top drop + curr - len bits are incremented through all values to
+       fill the table with replicated entries.
 
-  /* Make a table of values in order of bit lengths */
-  p = b;  i = 0;
-  do {
-    if ((j = *p++) != 0)
-      v[x[j]++] = i;
-  } while (++i < n);
-  n = x[g];                     /* set n to length of v */
+       root is the number of index bits for the root table.  When len exceeds
+       root, sub-tables are created pointed to by the root entry with an index
+       of the low root bits of huff.  This is saved in low to check for when a
+       new sub-table should be started.  drop is zero when the root table is
+       being filled, and drop is root when sub-tables are being filled.
 
+       When a new sub-table is needed, it is necessary to look ahead in the
+       code lengths to determine what size sub-table is needed.  The length
+       counts are used for this, and so count[] is decremented as codes are
+       entered in the tables.
 
-  /* Generate the Huffman codes and for each, make the table entries */
-  x[0] = i = 0;                 /* first Huffman code is zero */
-  p = v;                        /* grab values in bit order */
-  h = -1;                       /* no tables yet--level -1 */
-  w = -l;                       /* bits decoded == (l * h) */
-  u[0] = NULL;                  /* just to keep compilers happy */
-  q = NULL;                     /* ditto */
-  z = 0;                        /* ditto */
+       used keeps track of how many table entries have been allocated from the
+       provided *table space.  It is checked when a LENS table is being made
+       against the space in *table, ENOUGH, minus the maximum space needed by
+       the worst case distance code, MAXD.  This should never happen, but the
+       sufficiency of ENOUGH has not been proven exhaustively, hence the check.
+       This assumes that when type == LENS, bits == 9.
 
-  /* go through the bit lengths (k already is bits in shortest code) */
-  for (; k <= g; k++)
-  {
-    a = c[k];
-    while (a--)
-    {
-      /* here i is the Huffman code of length k bits for value *p */
-      /* make tables up to required level */
-      while (k > w + l)
-      {
-        h++;
-        w += l;                 /* previous table always l bits */
+       sym increments through all symbols, and the loop terminates when
+       all codes of length max, i.e. all codes, have been processed.  This
+       routine permits incomplete codes, so another loop after this one fills
+       in the rest of the decoding tables with invalid code markers.
+     */
 
-        /* compute minimum size table less than or equal to l bits */
-        z = g - w;
-        z = z > (uInt)l ? l : z;        /* table size upper limit */
-        if ((f = 1 << (j = k - w)) > a + 1)     /* try a k-w bit table */
-        {                       /* too few codes for k-w bit table */
-          f -= a + 1;           /* deduct codes from patterns left */
-          xp = c + k;
-          if (j < z)
-            while (++j < z)     /* try smaller tables up to z bits */
-            {
-              if ((f <<= 1) <= *++xp)
-                break;          /* enough codes to use up j bits */
-              f -= *xp;         /* else deduct codes from patterns */
-            }
+    /* set up for code type */
+    switch (type) {
+    case CODES:
+        base = extra = work;    /* dummy value--not used */
+        end = 19;
+        break;
+    case LENS:
+        base = lbase;
+        base -= 257;
+        extra = lext;
+        extra -= 257;
+        end = 256;
+        break;
+    default:            /* DISTS */
+        base = dbase;
+        extra = dext;
+        end = -1;
+    }
+
+    /* initialize state for loop */
+    huff = 0;                   /* starting code */
+    sym = 0;                    /* starting code symbol */
+    len = min;                  /* starting code length */
+    next = *table;              /* current table to fill in */
+    curr = root;                /* current table index bits */
+    drop = 0;                   /* current bits to drop from code for index */
+    low = (unsigned)(-1);       /* trigger new sub-table when len > root */
+    used = 1U << root;          /* use root table entries */
+    mask = used - 1;            /* mask for comparing low */
+
+    /* check available table space */
+    if (type == LENS && used >= ENOUGH - MAXD)
+        return 1;
+
+    /* process all codes and make table entries */
+    for (;;) {
+        /* create table entry */
+        this.bits = (unsigned char)(len - drop);
+        if ((int)(work[sym]) < end) {
+            this.op = (unsigned char)0;
+            this.val = work[sym];
         }
-        z = 1 << j;             /* table entries for j-bit table */
+        else if ((int)(work[sym]) > end) {
+            this.op = (unsigned char)(extra[work[sym]]);
+            this.val = base[work[sym]];
+        }
+        else {
+            this.op = (unsigned char)(32 + 64);         /* end of block */
+            this.val = 0;
+        }
 
-        /* allocate new table */
-        if (*hn + z > MANY)     /* (note: doesn't matter for fixed) */
-          return Z_DATA_ERROR;  /* overflow of MANY */
-        u[h] = q = hp + *hn;
-        *hn += z;
+        /* replicate for those indices with low len bits equal to huff */
+        incr = 1U << (len - drop);
+        fill = 1U << curr;
+        min = fill;                 /* save offset to next table */
+        do {
+            fill -= incr;
+            next[(huff >> drop) + fill] = this;
+        } while (fill != 0);
 
-        /* connect to last table, if there is one */
-        if (h)
-        {
-          x[h] = i;             /* save pattern for backing up */
-          r.bits = (Byte)l;     /* bits to dump before this table */
-          r.exop = (Byte)j;     /* bits in this table */
-          j = i >> (w - l);
-          r.base = (uInt)(q - u[h-1] - j);   /* offset to this table */
-          u[h-1][j] = r;        /* connect to last table */
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
         }
         else
-          *t = q;               /* first table is returned result */
-      }
+            huff = 0;
 
-      /* set up table entry in r */
-      r.bits = (Byte)(k - w);
-      if (p >= v + n)
-        r.exop = 128 + 64;      /* out of values--invalid code */
-      else if (*p < s)
-      {
-        r.exop = (Byte)(*p < 256 ? 0 : 32 + 64);     /* 256 is end-of-block */
-        r.base = *p++;          /* simple code is just the value */
-      }
-      else
-      {
-        r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
-        r.base = d[*p++ - s];
-      }
+        /* go to next symbol, update count, len */
+        sym++;
+        if (--(count[len]) == 0) {
+            if (len == max) break;
+            len = lens[work[sym]];
+        }
 
-      /* fill code-like entries with r */
-      f = 1 << (k - w);
-      for (j = i >> w; j < z; j += f)
-        q[j] = r;
+        /* create new sub-table if needed */
+        if (len > root && (huff & mask) != low) {
+            /* if first time, transition to sub-tables */
+            if (drop == 0)
+                drop = root;
 
-      /* backwards increment the k-bit code i */
-      for (j = 1 << (k - 1); i & j; j >>= 1)
-        i ^= j;
-      i ^= j;
+            /* increment past last table */
+            next += min;            /* here min is 1 << curr */
 
-      /* backup over finished tables */
-      mask = (1 << w) - 1;      /* needed on HP, cc -O bug */
-      while ((i & mask) != x[h])
-      {
-        h--;                    /* don't need to update q */
-        w -= l;
-        mask = (1 << w) - 1;
-      }
+            /* determine length of next table */
+            curr = len - drop;
+            left = (int)(1 << curr);
+            while (curr + drop < max) {
+                left -= count[curr + drop];
+                if (left <= 0) break;
+                curr++;
+                left <<= 1;
+            }
+
+            /* check for enough space */
+            used += 1U << curr;
+            if (type == LENS && used >= ENOUGH - MAXD)
+                return 1;
+
+            /* point entry in root table to sub-table */
+            low = huff & mask;
+            (*table)[low].op = (unsigned char)curr;
+            (*table)[low].bits = (unsigned char)root;
+            (*table)[low].val = (unsigned short)(next - *table);
+        }
     }
-  }
 
+    /*
+       Fill in rest of table for incomplete codes.  This loop is similar to the
+       loop above in incrementing huff for table indices.  It is assumed that
+       len is equal to curr + drop, so there is no loop needed to increment
+       through high index bits.  When the current sub-table is filled, the loop
+       drops back to the root table to fill in any remaining entries there.
+     */
+    this.op = (unsigned char)64;                /* invalid code marker */
+    this.bits = (unsigned char)(len - drop);
+    this.val = (unsigned short)0;
+    while (huff != 0) {
+        /* when done with sub-table, drop back to root table */
+        if (drop != 0 && (huff & mask) != low) {
+            drop = 0;
+            len = root;
+            next = *table;
+            this.bits = (unsigned char)len;
+        }
 
-  /* Return Z_BUF_ERROR if we were given an incomplete table */
-  return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
-}
+        /* put invalid code marker in table */
+        next[huff >> drop] = this;
 
-
-int zlib_inflate_trees_bits(
-	uInt *c,                /* 19 code lengths */
-	uInt *bb,               /* bits tree desired/actual depth */
-	inflate_huft **tb,      /* bits tree result */
-	inflate_huft *hp,       /* space for trees */
-	z_streamp z             /* for messages */
-)
-{
-  int r;
-  uInt hn = 0;          /* hufts used in space */
-  uInt *v;              /* work area for huft_build */
-  
-  v = WS(z)->tree_work_area_1;
-  r = huft_build(c, 19, 19, NULL, NULL, tb, bb, hp, &hn, v);
-  if (r == Z_DATA_ERROR)
-    z->msg = (char*)"oversubscribed dynamic bit lengths tree";
-  else if (r == Z_BUF_ERROR || *bb == 0)
-  {
-    z->msg = (char*)"incomplete dynamic bit lengths tree";
-    r = Z_DATA_ERROR;
-  }
-  return r;
-}
-
-int zlib_inflate_trees_dynamic(
-	uInt nl,                /* number of literal/length codes */
-	uInt nd,                /* number of distance codes */
-	uInt *c,                /* that many (total) code lengths */
-	uInt *bl,               /* literal desired/actual bit depth */
-	uInt *bd,               /* distance desired/actual bit depth */
-	inflate_huft **tl,      /* literal/length tree result */
-	inflate_huft **td,      /* distance tree result */
-	inflate_huft *hp,       /* space for trees */
-	z_streamp z             /* for messages */
-)
-{
-  int r;
-  uInt hn = 0;          /* hufts used in space */
-  uInt *v;              /* work area for huft_build */
-
-  /* allocate work area */
-  v = WS(z)->tree_work_area_2;
-
-  /* build literal/length tree */
-  r = huft_build(c, nl, 257, cplens, cplext, tl, bl, hp, &hn, v);
-  if (r != Z_OK || *bl == 0)
-  {
-    if (r == Z_DATA_ERROR)
-      z->msg = (char*)"oversubscribed literal/length tree";
-    else if (r != Z_MEM_ERROR)
-    {
-      z->msg = (char*)"incomplete literal/length tree";
-      r = Z_DATA_ERROR;
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
+        }
+        else
+            huff = 0;
     }
-    return r;
-  }
 
-  /* build distance tree */
-  r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, hp, &hn, v);
-  if (r != Z_OK || (*bd == 0 && nl > 257))
-  {
-    if (r == Z_DATA_ERROR)
-      z->msg = (char*)"oversubscribed distance tree";
-    else if (r == Z_BUF_ERROR) {
-#ifdef PKZIP_BUG_WORKAROUND
-      r = Z_OK;
-    }
-#else
-      z->msg = (char*)"incomplete distance tree";
-      r = Z_DATA_ERROR;
-    }
-    else if (r != Z_MEM_ERROR)
-    {
-      z->msg = (char*)"empty distance tree with lengths";
-      r = Z_DATA_ERROR;
-    }
-    return r;
-#endif
-  }
-
-  /* done */
-  return Z_OK;
-}
-
-
-int zlib_inflate_trees_fixed(
-	uInt *bl,                /* literal desired/actual bit depth */
-	uInt *bd,                /* distance desired/actual bit depth */
-	inflate_huft **tl,       /* literal/length tree result */
-	inflate_huft **td,       /* distance tree result */
-	inflate_huft *hp,       /* space for trees */
-	z_streamp z              /* for memory allocation */
-)
-{
-  int i;                /* temporary variable */
-  unsigned l[288];      /* length list for huft_build */
-  uInt *v;              /* work area for huft_build */
-
-  /* set up literal table */
-  for (i = 0; i < 144; i++)
-    l[i] = 8;
-  for (; i < 256; i++)
-    l[i] = 9;
-  for (; i < 280; i++)
-    l[i] = 7;
-  for (; i < 288; i++)          /* make a complete, but wrong code set */
-    l[i] = 8;
-  *bl = 9;
-  v = WS(z)->tree_work_area_1;
-  if ((i = huft_build(l, 288, 257, cplens, cplext, tl, bl, hp,  &i, v)) != 0)
-    return i;
-
-  /* set up distance table */
-  for (i = 0; i < 30; i++)      /* make an incomplete code set */
-    l[i] = 5;
-  *bd = 5;
-  if ((i = huft_build(l, 30, 0, cpdist, cpdext, td, bd, hp, &i, v)) > 1)
-    return i;
-
-  return Z_OK;
+    /* set return parameters */
+    *table += used;
+    *bits = root;
+    return 0;
 }

lib/zlib_inflate/inftrees.h

···
 /* inftrees.h -- header to use inftrees.c
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
+ * Copyright (C) 1995-2005 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /* WARNING: this file should *not* be used by applications. It is
···
    subject to change. Applications should only use zlib.h.
  */
 
-/* Huffman code lookup table entry--this entry is four bytes for machines
-   that have 16-bit pointers (e.g. PC's in the small or medium model). */
+/* Structure for decoding tables.  Each entry provides either the
+   information needed to do the operation requested by the code that
+   indexed that table entry, or it provides a pointer to another
+   table that indexes more bits of the code.  op indicates whether
+   the entry is a pointer to another table, a literal, a length or
+   distance, an end-of-block, or an invalid code.  For a table
+   pointer, the low four bits of op is the number of index bits of
+   that table.  For a length or distance, the low four bits of op
+   is the number of extra bits to get after the code.  bits is
+   the number of bits in this code or part of the code to drop off
+   of the bit buffer.  val is the actual byte to output in the case
+   of a literal, the base length or distance, or the offset from
+   the current table to the next table.  Each entry is four bytes. */
+typedef struct {
+    unsigned char op;           /* operation, extra bits, table bits */
+    unsigned char bits;         /* bits in this part of the code */
+    unsigned short val;         /* offset in table or code value */
+} code;
 
-#ifndef _INFTREES_H
-#define _INFTREES_H
-
-typedef struct inflate_huft_s inflate_huft;
-
-struct inflate_huft_s {
-  union {
-    struct {
-      Byte Exop;        /* number of extra bits or operation */
-      Byte Bits;        /* number of bits in this code or subcode */
-    } what;
-    uInt pad;           /* pad structure to a power of 2 (4 bytes for */
-  } word;               /*  16-bit, 8 bytes for 32-bit int's) */
-  uInt base;            /* literal, length base, distance base,
-                           or table offset */
-};
+/* op values as set by inflate_table():
+    00000000 - literal
+    0000tttt - table link, tttt != 0 is the number of table index bits
+    0001eeee - length or distance, eeee is the number of extra bits
+    01100000 - end of block
+    01000000 - invalid code
+ */
 
 /* Maximum size of dynamic tree.  The maximum found in a long but non-
-   exhaustive search was 1004 huft structures (850 for length/literals
-   and 154 for distances, the latter actually the result of an
-   exhaustive search).  The actual maximum is not known, but the
-   value below is more than safe. */
-#define MANY 1440
+   exhaustive search was 1444 code structures (852 for length/literals
+   and 592 for distances, the latter actually the result of an
+   exhaustive search).  The true maximum is not known, but the value
+   below is more than safe. */
+#define ENOUGH 2048
+#define MAXD 592
 
-extern int zlib_inflate_trees_bits (
-    uInt *,                     /* 19 code lengths */
-    uInt *,                     /* bits tree desired/actual depth */
-    inflate_huft **,            /* bits tree result */
-    inflate_huft *,             /* space for trees */
-    z_streamp);                 /* for messages */
+/* Type of code to build for inftable() */
+typedef enum {
+    CODES,
+    LENS,
+    DISTS
+} codetype;
 
-extern int zlib_inflate_trees_dynamic (
-    uInt,                       /* number of literal/length codes */
-    uInt,                       /* number of distance codes */
-    uInt *,                     /* that many (total) code lengths */
-    uInt *,                     /* literal desired/actual bit depth */
-    uInt *,                     /* distance desired/actual bit depth */
-    inflate_huft **,            /* literal/length tree result */
-    inflate_huft **,            /* distance tree result */
-    inflate_huft *,             /* space for trees */
-    z_streamp);                 /* for messages */
-
-extern int zlib_inflate_trees_fixed (
-    uInt *,                     /* literal desired/actual bit depth */
-    uInt *,                     /* distance desired/actual bit depth */
-    inflate_huft **,            /* literal/length tree result */
-    inflate_huft **,            /* distance tree result */
-    inflate_huft *,             /* space for trees */
-    z_streamp);                 /* for memory allocation */
-
-#endif /* _INFTREES_H */
+extern int zlib_inflate_table (codetype type, unsigned short *lens,
+                             unsigned codes, code **table,
+                             unsigned *bits, unsigned short *work);

lib/zlib_inflate/infutil.c

···
-/* inflate_util.c -- data and routines common to blocks and codes
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
- */
-
-#include <linux/zutil.h>
-#include "infblock.h"
-#include "inftrees.h"
-#include "infcodes.h"
-#include "infutil.h"
-
-struct inflate_codes_state;
-
-/* And'ing with mask[n] masks the lower n bits */
-uInt zlib_inflate_mask[17] = {
-    0x0000,
-    0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
-    0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
-};
-
-
-/* copy as much as possible from the sliding window to the output area */
-int zlib_inflate_flush(
-	inflate_blocks_statef *s,
-	z_streamp z,
-	int r
-)
-{
-  uInt n;
-  Byte *p;
-  Byte *q;
-
-  /* local copies of source and destination pointers */
-  p = z->next_out;
-  q = s->read;
-
-  /* compute number of bytes to copy as far as end of window */
-  n = (uInt)((q <= s->write ? s->write : s->end) - q);
-  if (n > z->avail_out) n = z->avail_out;
-  if (n && r == Z_BUF_ERROR) r = Z_OK;
-
-  /* update counters */
-  z->avail_out -= n;
-  z->total_out += n;
-
-  /* update check information */
-  if (s->checkfn != NULL)
-    z->adler = s->check = (*s->checkfn)(s->check, q, n);
-
-  /* copy as far as end of window */
-  memcpy(p, q, n);
-  p += n;
-  q += n;
-
-  /* see if more to copy at beginning of window */
-  if (q == s->end)
-  {
-    /* wrap pointers */
-    q = s->window;
-    if (s->write == s->end)
-      s->write = s->window;
-
-    /* compute bytes to copy */
-    n = (uInt)(s->write - q);
-    if (n > z->avail_out) n = z->avail_out;
-    if (n && r == Z_BUF_ERROR) r = Z_OK;
-
-    /* update counters */
-    z->avail_out -= n;
-    z->total_out += n;
-
-    /* update check information */
-    if (s->checkfn != NULL)
-      z->adler = s->check = (*s->checkfn)(s->check, q, n);
-
-    /* copy */
-    memcpy(p, q, n);
-    p += n;
-    q += n;
-  }
-
-  /* update pointers */
-  z->next_out = p;
-  s->read = q;
-
-  /* done */
-  return r;
-}

lib/zlib_inflate/infutil.h

···
 #ifndef _INFUTIL_H
 #define _INFUTIL_H
 
-#include <linux/zconf.h>
-#include "inftrees.h"
-#include "infcodes.h"
-
-typedef enum {
-      TYPE,     /* get type bits (3, including end bit) */
-      LENS,     /* get lengths for stored */
-      STORED,   /* processing stored block */
-      TABLE,    /* get table lengths */
-      BTREE,    /* get bit lengths tree for a dynamic block */
-      DTREE,    /* get length, distance trees for a dynamic block */
-      CODES,    /* processing fixed or dynamic block */
-      DRY,      /* output remaining window bytes */
-      B_DONE,   /* finished last block, done */
-      B_BAD}    /* got a data error--stuck here */
-inflate_block_mode;
-
-/* inflate blocks semi-private state */
-struct inflate_blocks_state {
-
-  /* mode */
-  inflate_block_mode  mode;     /* current inflate_block mode */
-
-  /* mode dependent information */
-  union {
-    uInt left;          /* if STORED, bytes left to copy */
-    struct {
-      uInt table;               /* table lengths (14 bits) */
-      uInt index;               /* index into blens (or border) */
-      uInt *blens;              /* bit lengths of codes */
-      uInt bb;                  /* bit length tree depth */
-      inflate_huft *tb;         /* bit length decoding tree */
-    } trees;            /* if DTREE, decoding info for trees */
-    struct {
-      inflate_codes_statef 
-         *codes;
-    } decode;           /* if CODES, current state */
-  } sub;                /* submode */
-  uInt last;            /* true if this block is the last block */
-
-  /* mode independent information */
-  uInt bitk;            /* bits in bit buffer */
-  uLong bitb;           /* bit buffer */
-  inflate_huft *hufts;  /* single malloc for tree space */
-  Byte *window;         /* sliding window */
-  Byte *end;            /* one byte after sliding window */
-  Byte *read;           /* window read pointer */
-  Byte *write;          /* window write pointer */
-  check_func checkfn;   /* check function */
-  uLong check;          /* check on output */
-
-};
-
-
-/* defines for inflate input/output */
-/*   update pointers and return */
-#define UPDBITS {s->bitb=b;s->bitk=k;}
-#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
-#define UPDOUT {s->write=q;}
-#define UPDATE {UPDBITS UPDIN UPDOUT}
-#define LEAVE {UPDATE return zlib_inflate_flush(s,z,r);}
-/*   get bytes and bits */
-#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
-#define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
-#define NEXTBYTE (n--,*p++)
-#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
-#define DUMPBITS(j) {b>>=(j);k-=(j);}
-/*   output bytes */
-#define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
-#define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
-#define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
-#define FLUSH {UPDOUT r=zlib_inflate_flush(s,z,r); LOADOUT}
-#define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
-#define OUTBYTE(a) {*q++=(Byte)(a);m--;}
-/*   load local pointers */
-#define LOAD {LOADIN LOADOUT}
-
-/* masks for lower bits (size given to avoid silly warnings with Visual C++) */
-extern uInt zlib_inflate_mask[17];
-
-/* copy as much as possible from the sliding window to the output area */
-extern int zlib_inflate_flush (
-    inflate_blocks_statef *,
-    z_streamp ,
-    int);
-
-/* inflate private state */
-typedef enum {
-      METHOD,   /* waiting for method byte */
-      FLAG,     /* waiting for flag byte */
-      DICT4,    /* four dictionary check bytes to go */
-      DICT3,    /* three dictionary check bytes to go */
-      DICT2,    /* two dictionary check bytes to go */
-      DICT1,    /* one dictionary check byte to go */
-      DICT0,    /* waiting for inflateSetDictionary */
-      BLOCKS,   /* decompressing blocks */
-      CHECK4,   /* four check bytes to go */
-      CHECK3,   /* three check bytes to go */
-      CHECK2,   /* two check bytes to go */
-      CHECK1,   /* one check byte to go */
-      I_DONE,   /* finished check, done */
-      I_BAD}    /* got an error--stay here */
-inflate_mode;
-
-struct internal_state {
-
-  /* mode */
-  inflate_mode  mode;   /* current inflate mode */
-
-  /* mode dependent information */
-  union {
-    uInt method;        /* if FLAGS, method byte */
-    struct {
-      uLong was;                /* computed check value */
-      uLong need;               /* stream check value */
-    } check;            /* if CHECK, check values to compare */
-    uInt marker;        /* if BAD, inflateSync's marker bytes count */
-  } sub;        /* submode */
-
-  /* mode independent information */
-  int  nowrap;          /* flag for no wrapper */
-  uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
-  inflate_blocks_statef 
-    *blocks;            /* current inflate_blocks state */
-
-};
-
-/* inflate codes private state */
-typedef enum {        /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
-      START,    /* x: set up for LEN */
-      LEN,      /* i: get length/literal/eob next */
-      LENEXT,   /* i: getting length extra (have base) */
-      DIST,     /* i: get distance next */
-      DISTEXT,  /* i: getting distance extra */
-      COPY,     /* o: copying bytes in window, waiting for space */
-      LIT,      /* o: got literal, waiting for output space */
-      WASH,     /* o: got eob, possibly still output waiting */
-      END,      /* x: got eob and all data flushed */
-      BADCODE}  /* x: got error */
-inflate_codes_mode;
-
-struct inflate_codes_state {
-
-  /* mode */
-  inflate_codes_mode mode;      /* current inflate_codes mode */
-
-  /* mode dependent information */
-  uInt len;
-  union {
-    struct {
-      inflate_huft *tree;       /* pointer into tree */
-      uInt need;                /* bits needed */
-    } code;             /* if LEN or DIST, where in tree */
-    uInt lit;           /* if LIT, literal */
-    struct {
-      uInt get;                 /* bits to get for extra */
-      uInt dist;                /* distance back to copy from */
-    } copy;             /* if EXT or COPY, where and how much */
-  } sub;                /* submode */
-
-  /* mode independent information */
-  Byte lbits;           /* ltree bits decoded per branch */
-  Byte dbits;           /* dtree bits decoder per branch */
-  inflate_huft *ltree;          /* literal/length/eob tree */
-  inflate_huft *dtree;          /* distance tree */
-
-};
+#include <linux/zlib.h>
 
 /* memory allocation for inflation */
 
 struct inflate_workspace {
-	inflate_codes_statef working_state;
-	struct inflate_blocks_state working_blocks_state;
-	struct internal_state internal_state;
-	unsigned int tree_work_area_1[19];
-	unsigned int tree_work_area_2[288];
-	unsigned working_blens[258 + 0x1f + 0x1f];
-	inflate_huft working_hufts[MANY];
+	struct inflate_state inflate_state;
 	unsigned char working_window[1 << MAX_WBITS];
 };