Copyright (c) 1990-2002 Info-ZIP. All rights reserved.
See the accompanying file LICENSE, version 2000-Apr-09 or later
(the contents of which are also included in unzip.h) for terms of use.
If, for some reason, all these files are missing, the Info-ZIP license
also may be found at: ftp://ftp.info-zip.org/pub/infozip/license.html
*/
version c17a, 04 Feb 2001 */
- Starting with UnZip 5.41 of 16-April-2000, this source file
is covered by the Info-Zip LICENSE cited above.
- Prior versions of this source file, found in UnZip source packages
up to UnZip 5.40, were put in the public domain.
The original copyright note by Mark Adler was:
"You can do whatever you like with this source file,
though I would prefer that if you modify it and
redistribute it that you include comments to that effect
with your name and the date. Thank you."
History:
vers date who what
---- --------- -------------- ------------------------------------
a ~~ Feb 92 M. Adler used full (large, one-step) lookup table
b1 21 Mar 92 M. Adler first version with partial lookup tables
b2 21 Mar 92 M. Adler fixed bug in fixed-code blocks
b3 22 Mar 92 M. Adler sped up match copies, cleaned up some
b4 25 Mar 92 M. Adler added prototypes; removed window[] (now
is the responsibility of unzip.h--also
changed name to slide[]), so needs diffs
for unzip.c and unzip.h (this allows
compiling in the small model on MSDOS);
fixed cast of q in huft_build();
b5 26 Mar 92 M. Adler got rid of unintended macro recursion.
b6 27 Mar 92 M. Adler got rid of nextbyte() routine. fixed
bug in inflate_fixed().
c1 30 Mar 92 M. Adler removed lbits, dbits environment variables.
changed BMAX to 16 for explode. Removed
OUTB usage, and replaced it with flush()--
this was a 20% speed improvement! Added
an explode.c (to replace unimplod.c) that
uses the huft routines here. Removed
register union.
c2 4 Apr 92 M. Adler fixed bug for file sizes a multiple of 32k.
c3 10 Apr 92 M. Adler reduced memory of code tables made by
huft_build significantly (factor of two to
three).
c4 15 Apr 92 M. Adler added NOMEMCPY do kill use of memcpy().
worked around a Turbo C optimization bug.
c5 21 Apr 92 M. Adler added the WSIZE #define to allow reducing
the 32K window size for specialized
applications.
c6 31 May 92 M. Adler added some typecasts to eliminate warnings
c7 27 Jun 92 G. Roelofs added some more typecasts (444: MSC bug).
c8 5 Oct 92 J-l. Gailly added ifdef'd code to deal with PKZIP bug.
c9 9 Oct 92 M. Adler removed a memory error message (~line 416).
c10 17 Oct 92 G. Roelofs changed ULONG/UWORD/byte to ulg/ush/uch,
removed old inflate, renamed inflate_entry
to inflate, added Mark's fix to a comment.
c10.5 14 Dec 92 M. Adler fix up error messages for incomplete trees.
c11 2 Jan 93 M. Adler fixed bug in detection of incomplete
tables, and removed assumption that EOB is
the longest code (bad assumption).
c12 3 Jan 93 M. Adler make tables for fixed blocks only once.
c13 5 Jan 93 M. Adler allow all zero length codes (pkzip 2.04c
outputs one zero length code for an empty
distance tree).
c14 12 Mar 93 M. Adler made inflate.c standalone with the
introduction of inflate.h.
c14b 16 Jul 93 G. Roelofs added (unsigned) typecast to w at 470.
c14c 19 Jul 93 J. Bush changed v[N_MAX], l[288], ll[28x+3x] arrays
to static for Amiga.
c14d 13 Aug 93 J-l. Gailly de-complicatified Mark's c[*p++]++ thing.
c14e 8 Oct 93 G. Roelofs changed memset() to memzero().
c14f 22 Oct 93 G. Roelofs renamed quietflg to qflag; made Trace()
conditional; added inflate_free().
c14g 28 Oct 93 G. Roelofs changed l/(lx+1) macro to pointer (Cray bug)
c14h 7 Dec 93 C. Ghisler huft_build() optimizations.
c14i 9 Jan 94 A. Verheijen set fixed_t{d,l} to NULL after freeing;
G. Roelofs check NEXTBYTE macro for EOF.
c14j 23 Jan 94 G. Roelofs removed Ghisler "optimizations"; ifdef'd
EOF check.
c14k 27 Feb 94 G. Roelofs added some typecasts to avoid warnings.
c14l 9 Apr 94 G. Roelofs fixed split comments on preprocessor lines
to avoid bug in Encore compiler.
c14m 7 Jul 94 P. Kienitz modified to allow assembler version of
inflate_codes() (define ASM_INFLATECODES)
c14n 22 Jul 94 G. Roelofs changed fprintf to macro for DLL versions
c14o 23 Aug 94 C. Spieler added a newline to a debug statement;
G. Roelofs added another typecast to avoid MSC warning
c14p 4 Oct 94 G. Roelofs added (voidp *) cast to free() argument
c14q 30 Oct 94 G. Roelofs changed fprintf macro to MESSAGE()
c14r 1 Nov 94 G. Roelofs fixed possible redefinition of CHECK_EOF
c14s 7 May 95 S. Maxwell OS/2 DLL globals stuff incorporated;
P. Kienitz "fixed" ASM_INFLATECODES macro/prototype
c14t 18 Aug 95 G. Roelofs added UZinflate() to use zlib functions;
changed voidp to zvoid; moved huft_build()
and huft_free() to end of file
c14u 1 Oct 95 G. Roelofs moved G into definition of MESSAGE macro
c14v 8 Nov 95 P. Kienitz changed ASM_INFLATECODES to use a regular
call with __G__ instead of a macro
c15 3 Aug 96 M. Adler fixed bomb-bug on random input data (Adobe)
c15b 24 Aug 96 M. Adler more fixes for random input data
c15c 28 Mar 97 G. Roelofs changed USE_ZLIB fatal exit code from
PK_MEM2 to PK_MEM3
c16 20 Apr 97 J. Altman added memzero(v[]) in huft_build()
c16b 29 Mar 98 C. Spieler modified DLL code for slide redirection
c16c 04 Apr 99 C. Spieler fixed memory leaks when processing gets
stopped because of input data errors
c16d 05 Jul 99 C. Spieler take care of FLUSH() return values and
stop processing in case of errors
c17 31 Dec 00 C. Spieler added preliminary support for Deflate64
c17a 04 Feb 01 C. Spieler complete integration of Deflate64 support
c17b 16 Feb 02 C. Spieler changed type of "extra bits" arrays and
corresponding huft_buid() parameter e from
ush into uch, to save space
*/
Inflate deflated (PKZIP's method 8 compressed) data. The compression
method searches for as much of the current string of bytes (up to a
length of 258) in the previous 32K bytes. If it doesn't find any
matches (of at least length 3), it codes the next byte. Otherwise, it
codes the length of the matched string and its distance backwards from
the current position. There is a single Huffman code that codes both
single bytes (called "literals") and match lengths. A second Huffman
code codes the distance information, which follows a length code. Each
length or distance code actually represents a base value and a number
of "extra" (sometimes zero) bits to get to add to the base value. At
the end of each deflated block is a special end-of-block (EOB) literal/
length code. The decoding process is basically: get a literal/length
code; if EOB then done; if a literal, emit the decoded byte; if a
length then get the distance and emit the referred-to bytes from the
sliding window of previously emitted data.
There are (currently) three kinds of inflate blocks: stored, fixed, and
dynamic. The compressor outputs a chunk of data at a time and decides
which method to use on a chunk-by-chunk basis. A chunk might typically
be 32K to 64K, uncompressed. If the chunk is uncompressible, then the
"stored" method is used. In this case, the bytes are simply stored as
is, eight bits per byte, with none of the above coding. The bytes are
preceded by a count, since there is no longer an EOB code.
If the data are compressible, then either the fixed or dynamic methods
are used. In the dynamic method, the compressed data are preceded by
an encoding of the literal/length and distance Huffman codes that are
to be used to decode this block. The representation is itself Huffman
coded, and so is preceded by a description of that code. These code
descriptions take up a little space, and so for small blocks, there is
a predefined set of codes, called the fixed codes. The fixed method is
used if the block ends up smaller that way (usually for quite small
chunks); otherwise the dynamic method is used. In the latter case, the
codes are customized to the probabilities in the current block and so
can code it much better than the pre-determined fixed codes can.
The Huffman codes themselves are decoded using a multi-level table
lookup, in order to maximize the speed of decoding plus the speed of
building the decoding tables. See the comments below that precede the
lbits and dbits tuning parameters.
GRR: return values(?)
0 OK
1 incomplete table
2 bad input
3 not enough memory
the following return codes are passed through from FLUSH() errors
50 (PK_DISK) "overflow of output space"
80 (IZ_CTRLC) "canceled by user's request"
*/
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.
14. The Deflate64 (PKZIP method 9) variant of the compression algorithm
differs from "classic" deflate in the following 3 aspect:
a) The size of the sliding history window is expanded to 64 kByte.
b) The previously unused distance codes #30 and #31 code distances
from 32769 to 49152 and 49153 to 65536. Both codes take 14 bits
of extra data to determine the exact position in their 16 kByte
range.
c) The last lit/length code #285 gets a different meaning. Instead
of coding a fixed maximum match length of 258, it is used as a
"generic" match length code, capable of coding any length from
3 (min match length + 0) to 65538 (min match length + 65535).
This means that the length code #285 takes 16 bits (!) of uncoded
extra data, added to a fixed min length of 3.
Changes a) and b) would have been transparent for valid deflated
data, but change c) requires to switch decoder configurations between
Deflate and Deflate64 modes.
*/
#define PKZIP_BUG_WORKAROUND
inflate.h must supply the uch slide[WSIZE] array, the zvoid typedef
(void if (void *) is accepted, else char) and the NEXTBYTE,
FLUSH() and memzero macros. If the window size is not 32K, it
should also define WSIZE. If INFMOD is defined, it can include
compiled functions to support the NEXTBYTE and/or FLUSH() macros.
There are defaults for NEXTBYTE and FLUSH() below for use as
examples of what those functions need to do. Normally, you would
also want FLUSH() to compute a crc on the data. inflate.h also
needs to provide these typedefs:
typedef unsigned char uch;
typedef unsigned short ush;
typedef unsigned long ulg;
This module uses the external functions malloc() and free() (and
probably memset() or bzero() in the memzero() macro). Their
prototypes are normally found in <string.h> and <stdlib.h>.
*/
#define __INFLATE_C
#define INFMOD
#include "inflate.h"
#define INVALID_CODE 99
#define IS_INVALID_CODE(c) ((c) == INVALID_CODE)
#ifndef WSIZE
# ifdef USE_DEFLATE64
# define WSIZE 65536L /* window size--must be a power of two, and */
# else
# define WSIZE 0x8000 /* window size--must be a power of two, and */
# endif
#endif
#if (defined(USE_DEFLATE64) && defined(INT_16BIT))
# define UINT_D64 ulg
#else
# define UINT_D64 unsigned
#endif
#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
# define wsize G._wsize /* wsize is a variable */
#else
# define wsize WSIZE /* wsize is a constant */
#endif
#ifndef NEXTBYTE
# define NEXTBYTE getchar()
#endif
#ifndef MESSAGE
# define MESSAGE(str,len,flag) fprintf(stderr,(char *)(str))
#endif
#ifndef FLUSH
# define FLUSH(n) \
(((extent)fwrite(redirSlide, 1, (extent)(n), stdout) == (extent)(n)) ? \
0 : PKDISK)
#endif
0x8000 might be interpreted as -32,768 by the library function. When
support for Deflate64 is enabled, the window size is 64K and the
simple fwrite statement is definitely broken for 16-bit compilers. */
#ifndef Trace
# ifdef DEBUG
# define Trace(x) fprintf x
# else
# define Trace(x)
# endif
#endif
#ifdef USE_ZLIB
GRR: return values for both original inflate() and UZinflate()
0 OK
1 incomplete table(?)
2 bad input
3 not enough memory
*/
int UZinflate(__G__ is_defl64)
__GDEF
int is_defl64;
{
int retval = 0;
int err=Z_OK;
#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
if (G.redirect_slide)
wsize = G.redirect_size, redirSlide = G.redirect_buffer;
else
wsize = WSIZE, redirSlide = slide;
#endif
G.dstrm.next_out = redirSlide;
G.dstrm.avail_out = wsize;
G.dstrm.next_in = G.inptr;
G.dstrm.avail_in = G.incnt;
if (!G.inflInit) {
unsigned i;
int windowBits;
if (zlib_version[0] != ZLIB_VERSION[0]) {
Info(slide, 0x21, ((char *)slide,
"error: incompatible zlib version (expected %s, found %s)\n",
ZLIB_VERSION, zlib_version));
return 3;
} else if (strcmp(zlib_version, ZLIB_VERSION) != 0)
Info(slide, 0x21, ((char *)slide,
"warning: different zlib version (expected %s, using %s)\n",
ZLIB_VERSION, zlib_version));
for (i = (unsigned)wsize, windowBits = 0;
!(i & 1); i >>= 1, ++windowBits);
if ((unsigned)windowBits > (unsigned)15)
windowBits = 15;
else if (windowBits < 8)
windowBits = 8;
G.dstrm.zalloc = (alloc_func)Z_NULL;
G.dstrm.zfree = (free_func)Z_NULL;
Trace((stderr, "initializing inflate()\n"));
err = inflateInit2(&G.dstrm, -windowBits);
if (err == Z_MEM_ERROR)
return 3;
else if (err != Z_OK)
Trace((stderr, "oops! (inflateInit2() err = %d)\n", err));
G.inflInit = 1;
}
#ifdef FUNZIP
while (err != Z_STREAM_END) {
#else
while (G.csize > 0) {
Trace((stderr, "first loop: G.csize = %ld\n", G.csize));
#endif
while (G.dstrm.avail_out > 0) {
err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);
if (err == Z_DATA_ERROR) {
retval = 2; goto uzinflate_cleanup_exit;
} else if (err == Z_MEM_ERROR) {
retval = 3; goto uzinflate_cleanup_exit;
} else if (err != Z_OK && err != Z_STREAM_END)
Trace((stderr, "oops! (inflate(first loop) err = %d)\n", err));
#ifdef FUNZIP
if (err == Z_STREAM_END)
#else
if (G.csize <= 0L)
#endif
break;
if (G.dstrm.avail_in <= 0) {
if (fillinbuf(__G) == 0) {
retval = 2; goto uzinflate_cleanup_exit;
}
G.dstrm.next_in = G.inptr;
G.dstrm.avail_in = G.incnt;
}
Trace((stderr, " avail_in = %d\n", G.dstrm.avail_in));
}
if ((retval = FLUSH(wsize - G.dstrm.avail_out)) != 0)
goto uzinflate_cleanup_exit;
Trace((stderr, "inside loop: flushing %ld bytes (ptr diff = %ld)\n",
(long)(wsize - G.dstrm.avail_out),
(long)(G.dstrm.next_out-(Bytef *)redirSlide)));
G.dstrm.next_out = redirSlide;
G.dstrm.avail_out = wsize;
}
Trace((stderr, "beginning final loop: err = %d\n", err));
while (err != Z_STREAM_END) {
err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);
if (err == Z_DATA_ERROR) {
retval = 2; goto uzinflate_cleanup_exit;
} else if (err == Z_MEM_ERROR) {
retval = 3; goto uzinflate_cleanup_exit;
} else if (err == Z_BUF_ERROR) {
Trace((stderr,
"zlib inflate() did not detect stream end (%s, %s)\n",
G.zipfn, G.filename));
break;
} else if (err != Z_OK && err != Z_STREAM_END) {
Trace((stderr, "oops! (inflate(final loop) err = %d)\n", err));
DESTROYGLOBALS();
EXIT(PK_MEM3);
}
if ((retval = FLUSH(wsize - G.dstrm.avail_out)) != 0)
goto uzinflate_cleanup_exit;
Trace((stderr, "final loop: flushing %ld bytes (ptr diff = %ld)\n",
(long)(wsize - G.dstrm.avail_out),
(long)(G.dstrm.next_out-(Bytef *)redirSlide)));
G.dstrm.next_out = redirSlide;
G.dstrm.avail_out = wsize;
}
Trace((stderr, "total in = %ld, total out = %ld\n", G.dstrm.total_in,
G.dstrm.total_out));
G.inptr = (uch *)G.dstrm.next_in;
G.incnt = (G.inbuf + INBUFSIZ) - G.inptr;
uzinflate_cleanup_exit:
err = inflateReset(&G.dstrm);
if (err != Z_OK)
Trace((stderr, "oops! (inflateReset() err = %d)\n", err));
return retval;
}
#else
#ifndef OF
# ifdef __STDC__
# define OF(a) a
# else
# define OF(a) ()
# endif
#endif
int inflate_codes OF((__GPRO__ struct huft *tl, struct huft *td,
int bl, int bd));
static int inflate_stored OF((__GPRO));
static int inflate_fixed OF((__GPRO));
static int inflate_dynamic OF((__GPRO));
static int inflate_block OF((__GPRO__ int *e));
stream to find repeated byte strings. This is implemented here as a
circular buffer. The index is updated simply by incrementing and then
and'ing with 0x7fff (32K-1). */
to be usable as if it were declared "uch slide[32768];" or as just
"uch *slide;" and then malloc'ed in the latter case. The definition
must be in unzip.h, included above. */
static ZCONST unsigned border[] = {
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
#ifdef USE_DEFLATE64
static ZCONST ush cplens64[] = {
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, 3, 0, 0};
#else
# define cplens32 cplens
#endif
static ZCONST ush cplens32[] = {
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};
#ifdef USE_DEFLATE64
static ZCONST uch cplext64[] = {
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, 16, INVALID_CODE, INVALID_CODE};
#else
# define cplext32 cplext
#endif
static ZCONST uch cplext32[] = {
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, INVALID_CODE, INVALID_CODE};
static ZCONST ush cpdist[] = {
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,
#if (defined(USE_DEFLATE64) || defined(PKZIP_BUG_WORKAROUND))
8193, 12289, 16385, 24577, 32769, 49153};
#else
8193, 12289, 16385, 24577};
#endif
#ifdef USE_DEFLATE64
static ZCONST uch cpdext64[] = {
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, 14, 14};
#else
# define cpdext32 cpdext
#endif
static ZCONST uch cpdext32[] = {
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,
#ifdef PKZIP_BUG_WORKAROUND
12, 12, 13, 13, INVALID_CODE, INVALID_CODE};
#else
12, 12, 13, 13};
#endif
#ifdef PKZIP_BUG_WORKAROUND
# define MAXLITLENS 288
#else
# define MAXLITLENS 286
#endif
#if (defined(USE_DEFLATE64) || defined(PKZIP_BUG_WORKAROUND))
# define MAXDISTS 32
#else
# define MAXDISTS 30
#endif
#if 0
ZCONST ush near mask_bits[] = {
0x0000,
0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
};
#endif
The usage is:
NEEDBITS(j)
x = b & mask_bits[j];
DUMPBITS(j)
where NEEDBITS makes sure that b has at least j bits in it, and
DUMPBITS removes the bits from b. The macros use the variable k
for the number of bits in b. Normally, b and k are register
variables for speed and are initialized at the begining of a
routine that uses these macros from a global bit buffer and count.
In order to not ask for more bits than there are in the compressed
stream, the Huffman tables are constructed to only ask for just
enough bits to make up the end-of-block code (value 256). Then no
bytes need to be "returned" to the buffer at the end of the last
block. See the huft_build() routine.
*/
#if 0
ulg bb;
unsigned bk;
#endif
#ifndef CHECK_EOF
# define CHECK_EOF
#endif
#ifndef CHECK_EOF
# define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE)<<k;k+=8;}}
#else
# define NEEDBITS(n) {while(k<(n)){int c=NEXTBYTE;\
if(c==EOF){retval=1;goto cleanup_and_exit;}\
b|=((ulg)c)<<k;k+=8;}}
#endif
#define DUMPBITS(n) {b>>=(n);k-=(n);}
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
are 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.
*/
static ZCONST int lbits = 9;
static ZCONST int dbits = 6;
#ifndef ASM_INFLATECODES
int inflate_codes(__G__ tl, td, bl, bd)
__GDEF
struct huft *tl, *td;
int bl, bd;
Return an error code or zero if it all goes ok. */
{
register unsigned e;
unsigned d;
UINT_D64 n;
UINT_D64 w;
struct huft *t;
unsigned ml, md;
register ulg b;
register unsigned k;
int retval = 0;
b = G.bb;
k = G.bk;
w = G.wp;
ml = mask_bits[bl];
md = mask_bits[bd];
while (1)
{
NEEDBITS((unsigned)bl)
t = tl + ((unsigned)b & ml);
while (1) {
DUMPBITS(t->b)
if ((e = t->e) == 32)
{
redirSlide[w++] = (uch)t->v.n;
if (w == wsize)
{
if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;
w = 0;
}
break;
}
if (e < 31)
{
NEEDBITS(e)
n = t->v.n + ((unsigned)b & mask_bits[e]);
DUMPBITS(e)
NEEDBITS((unsigned)bd)
t = td + ((unsigned)b & md);
while (1) {
DUMPBITS(t->b)
if ((e = t->e) < 32)
break;
if (IS_INVALID_CODE(e))
return 1;
e &= 31;
NEEDBITS(e)
t = t->v.t + ((unsigned)b & mask_bits[e]);
}
NEEDBITS(e)
d = (unsigned)w - t->v.n - ((unsigned)b & mask_bits[e]);
DUMPBITS(e)
do {
#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
if (G.redirect_slide) {
if ((UINT_D64)d >= wsize)
return 1;
e = (unsigned)(wsize - (d > (unsigned)w ? (UINT_D64)d : w));
}
else
#endif
e = (unsigned)(wsize -
((d &= (unsigned)(wsize-1)) > (unsigned)w ?
(UINT_D64)d : w));
if ((UINT_D64)e > n) e = (unsigned)n;
n -= e;
#ifndef NOMEMCPY
if ((unsigned)w - d >= e)
{
memcpy(redirSlide + (unsigned)w, redirSlide + d, e);
w += e;
d += e;
}
else
#endif
do {
redirSlide[w++] = redirSlide[d++];
} while (--e);
if (w == wsize)
{
if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;
w = 0;
}
} while (n);
break;
}
if (e == 31)
{
goto cleanup_decode;
}
if (IS_INVALID_CODE(e))
return 1;
e &= 31;
NEEDBITS(e)
t = t->v.t + ((unsigned)b & mask_bits[e]);
}
}
cleanup_decode:
G.wp = (unsigned)w;
G.bb = b;
G.bk = k;
cleanup_and_exit:
return retval;
}
#endif
static int inflate_stored(__G)
__GDEF
{
UINT_D64 w;
unsigned n;
register ulg b;
register unsigned k;
int retval = 0;
Trace((stderr, "\nstored block"));
b = G.bb;
k = G.bk;
w = G.wp;
n = k & 7;
DUMPBITS(n);
NEEDBITS(16)
n = ((unsigned)b & 0xffff);
DUMPBITS(16)
NEEDBITS(16)
if (n != (unsigned)((~b) & 0xffff))
return 1;
DUMPBITS(16)
while (n--)
{
NEEDBITS(8)
redirSlide[w++] = (uch)b;
if (w == wsize)
{
if ((retval = FLUSH(w)) != 0) goto cleanup_and_exit;
w = 0;
}
DUMPBITS(8)
}
G.wp = (unsigned)w;
G.bb = b;
G.bk = k;
cleanup_and_exit:
return retval;
}
#if 0
struct huft *fixed_tl = (struct huft *)NULL;
struct huft *fixed_td;
int fixed_bl, fixed_bd;
#endif
static int inflate_fixed(__G)
__GDEF
either replace this with a custom decoder, or at least precompute the
Huffman tables. */
{
Trace((stderr, "\nliteral block"));
if (G.fixed_tl == (struct huft *)NULL)
{
int i;
unsigned l[288];
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++)
l[i] = 8;
G.fixed_bl = 7;
#ifdef USE_DEFLATE64
if ((i = huft_build(__G__ l, 288, 257, G.cplens, G.cplext,
&G.fixed_tl, &G.fixed_bl)) != 0)
#else
if ((i = huft_build(__G__ l, 288, 257, cplens, cplext,
&G.fixed_tl, &G.fixed_bl)) != 0)
#endif
{
G.fixed_tl = (struct huft *)NULL;
return i;
}
for (i = 0; i < MAXDISTS; i++)
l[i] = 5;
G.fixed_bd = 5;
#ifdef USE_DEFLATE64
if ((i = huft_build(__G__ l, MAXDISTS, 0, cpdist, G.cpdext,
&G.fixed_td, &G.fixed_bd)) > 1)
#else
if ((i = huft_build(__G__ l, MAXDISTS, 0, cpdist, cpdext,
&G.fixed_td, &G.fixed_bd)) > 1)
#endif
{
huft_free(G.fixed_tl);
G.fixed_td = G.fixed_tl = (struct huft *)NULL;
return i;
}
}
return inflate_codes(__G__ G.fixed_tl, G.fixed_td,
G.fixed_bl, G.fixed_bd);
}
static int inflate_dynamic(__G)
__GDEF
{
int i;
unsigned j;
unsigned l;
unsigned m;
unsigned n;
struct huft *tl;
struct huft *td;
int bl;
int bd;
unsigned nb;
unsigned nl;
unsigned nd;
unsigned ll[MAXLITLENS+MAXDISTS];
register ulg b;
register unsigned k;
int retval = 0;
Trace((stderr, "\ndynamic block"));
b = G.bb;
k = G.bk;
NEEDBITS(5)
nl = 257 + ((unsigned)b & 0x1f);
DUMPBITS(5)
NEEDBITS(5)
nd = 1 + ((unsigned)b & 0x1f);
DUMPBITS(5)
NEEDBITS(4)
nb = 4 + ((unsigned)b & 0xf);
DUMPBITS(4)
if (nl > MAXLITLENS || nd > MAXDISTS)
return 1;
for (j = 0; j < nb; j++)
{
NEEDBITS(3)
ll[border[j]] = (unsigned)b & 7;
DUMPBITS(3)
}
for (; j < 19; j++)
ll[border[j]] = 0;
bl = 7;
retval = huft_build(__G__ ll, 19, 19, NULL, NULL, &tl, &bl);
if (bl == 0)
retval = 1;
if (retval)
{
if (retval == 1)
huft_free(tl);
return retval;
}
n = nl + nd;
m = mask_bits[bl];
i = l = 0;
while ((unsigned)i < n)
{
NEEDBITS((unsigned)bl)
j = (td = tl + ((unsigned)b & m))->b;
DUMPBITS(j)
j = td->v.n;
if (j < 16)
ll[i++] = l = j;
else if (j == 16)
{
NEEDBITS(2)
j = 3 + ((unsigned)b & 3);
DUMPBITS(2)
if ((unsigned)i + j > n)
return 1;
while (j--)
ll[i++] = l;
}
else if (j == 17)
{
NEEDBITS(3)
j = 3 + ((unsigned)b & 7);
DUMPBITS(3)
if ((unsigned)i + j > n)
return 1;
while (j--)
ll[i++] = 0;
l = 0;
}
else
{
NEEDBITS(7)
j = 11 + ((unsigned)b & 0x7f);
DUMPBITS(7)
if ((unsigned)i + j > n)
return 1;
while (j--)
ll[i++] = 0;
l = 0;
}
}
huft_free(tl);
G.bb = b;
G.bk = k;
bl = lbits;
#ifdef USE_DEFLATE64
retval = huft_build(__G__ ll, nl, 257, G.cplens, G.cplext, &tl, &bl);
#else
retval = huft_build(__G__ ll, nl, 257, cplens, cplext, &tl, &bl);
#endif
if (bl == 0)
retval = 1;
if (retval)
{
if (retval == 1) {
if (!uO.qflag)
MESSAGE((uch *)"(incomplete l-tree) ", 21L, 1);
huft_free(tl);
}
return retval;
}
bd = dbits;
#ifdef USE_DEFLATE64
retval = huft_build(__G__ ll + nl, nd, 0, cpdist, G.cpdext, &td, &bd);
#else
retval = huft_build(__G__ ll + nl, nd, 0, cpdist, cpdext, &td, &bd);
#endif
#ifdef PKZIP_BUG_WORKAROUND
if (retval == 1)
retval = 0;
#endif
if (bd == 0 && nl > 257)
retval = 1;
if (retval)
{
if (retval == 1) {
if (!uO.qflag)
MESSAGE((uch *)"(incomplete d-tree) ", 21L, 1);
huft_free(td);
}
huft_free(tl);
return retval;
}
retval = inflate_codes(__G__ tl, td, bl, bd);
cleanup_and_exit:
huft_free(tl);
huft_free(td);
return retval;
}
static int inflate_block(__G__ e)
__GDEF
int *e;
{
unsigned t;
register ulg b;
register unsigned k;
int retval = 0;
b = G.bb;
k = G.bk;
NEEDBITS(1)
*e = (int)b & 1;
DUMPBITS(1)
NEEDBITS(2)
t = (unsigned)b & 3;
DUMPBITS(2)
G.bb = b;
G.bk = k;
if (t == 2)
return inflate_dynamic(__G);
if (t == 0)
return inflate_stored(__G);
if (t == 1)
return inflate_fixed(__G);
retval = 2;
cleanup_and_exit:
return retval;
}
int inflate(__G__ is_defl64)
__GDEF
int is_defl64;
{
int e;
int r;
#ifdef DEBUG
unsigned h = 0;
#endif
#if (defined(DLL) && !defined(NO_SLIDE_REDIR))
if (G.redirect_slide)
wsize = G.redirect_size, redirSlide = G.redirect_buffer;
else
wsize = WSIZE, redirSlide = slide;
#endif
G.wp = 0;
G.bk = 0;
G.bb = 0;
#ifdef USE_DEFLATE64
if (is_defl64) {
G.cplens = cplens64;
G.cplext = cplext64;
G.cpdext = cpdext64;
G.fixed_tl = G.fixed_tl64;
G.fixed_bl = G.fixed_bl64;
G.fixed_td = G.fixed_td64;
G.fixed_bd = G.fixed_bd64;
} else {
G.cplens = cplens32;
G.cplext = cplext32;
G.cpdext = cpdext32;
G.fixed_tl = G.fixed_tl32;
G.fixed_bl = G.fixed_bl32;
G.fixed_td = G.fixed_td32;
G.fixed_bd = G.fixed_bd32;
}
#else
if (is_defl64) {
* compiled with inconsistent option setting. Handle this by
* returning with "bad input" error code.
*/
Trace((stderr, "\nThis inflate() cannot handle Deflate64!\n"));
return 2;
}
#endif
do {
#ifdef DEBUG
G.hufts = 0;
#endif
if ((r = inflate_block(__G__ &e)) != 0)
return r;
#ifdef DEBUG
if (G.hufts > h)
h = G.hufts;
#endif
} while (!e);
Trace((stderr, "\n%u bytes in Huffman tables (%u/entry)\n",
h * (unsigned)sizeof(struct huft), (unsigned)sizeof(struct huft)));
#ifdef USE_DEFLATE64
if (is_defl64) {
G.fixed_tl64 = G.fixed_tl;
G.fixed_bl64 = G.fixed_bl;
G.fixed_td64 = G.fixed_td;
G.fixed_bd64 = G.fixed_bd;
} else {
G.fixed_tl32 = G.fixed_tl;
G.fixed_bl32 = G.fixed_bl;
G.fixed_td32 = G.fixed_td;
G.fixed_bd32 = G.fixed_bd;
}
#endif
return (FLUSH(G.wp));
}
int inflate_free(__G)
__GDEF
{
if (G.fixed_tl != (struct huft *)NULL)
{
huft_free(G.fixed_td);
huft_free(G.fixed_tl);
G.fixed_td = G.fixed_tl = (struct huft *)NULL;
}
return 0;
}
#endif
* GRR: moved huft_build() and huft_free() down here; used by explode()
* and fUnZip regardless of whether USE_ZLIB defined or not
*/
#define BMAX 16 /* maximum bit length of any code (16 for explode) */
#define N_MAX 288 /* maximum number of codes in any set */
int huft_build(__G__ b, n, s, d, e, t, m)
__GDEF
ZCONST unsigned *b;
unsigned n;
unsigned s;
ZCONST ush *d;
ZCONST uch *e;
struct huft **t;
int *m;
tables to decode that set of codes. Return zero on success, one if
the given code set is incomplete (the tables are still built in this
case), two if the input is invalid (all zero length codes or an
oversubscribed set of lengths), and three if not enough memory.
The code with value 256 is special, and the tables are constructed
so that no bits beyond that code are fetched when that code is
decoded. */
{
unsigned a;
unsigned c[BMAX+1];
unsigned el;
unsigned f;
int g;
int h;
register unsigned i;
register unsigned j;
register int k;
int lx[BMAX+1];
int *l = lx+1;
register unsigned *p;
register struct huft *q;
struct huft r;
struct huft *u[BMAX];
unsigned v[N_MAX];
register int w;
unsigned x[BMAX+1];
unsigned *xp;
int y;
unsigned z;
el = n > 256 ? b[256] : BMAX;
memzero((char *)c, sizeof(c));
p = (unsigned *)b; i = n;
do {
c[*p]++; p++;
} while (--i);
if (c[0] == n)
{
*t = (struct huft *)NULL;
*m = 0;
return 0;
}
for (j = 1; j <= BMAX; j++)
if (c[j])
break;
k = j;
if ((unsigned)*m < j)
*m = j;
for (i = BMAX; i; i--)
if (c[i])
break;
g = i;
if ((unsigned)*m > i)
*m = i;
for (y = 1 << j; j < i; j++, y <<= 1)
if ((y -= c[j]) < 0)
return 2;
if ((y -= c[i]) < 0)
return 2;
c[i] += y;
x[1] = j = 0;
p = c + 1; xp = x + 2;
while (--i) {
*xp++ = (j += *p++);
}
memzero((char *)v, sizeof(v));
p = (unsigned *)b; i = 0;
do {
if ((j = *p++) != 0)
v[x[j]++] = i;
} while (++i < n);
n = x[g];
x[0] = i = 0;
p = v;
h = -1;
w = l[-1] = 0;
u[0] = (struct huft *)NULL;
q = (struct huft *)NULL;
z = 0;
for (; k <= g; k++)
{
a = c[k];
while (a--)
{
while (k > w + l[h])
{
w += l[h++];
z = (z = g - w) > (unsigned)*m ? *m : z;
if ((f = 1 << (j = k - w)) > a + 1)
{
f -= a + 1;
xp = c + k;
while (++j < z)
{
if ((f <<= 1) <= *++xp)
break;
f -= *xp;
}
}
if ((unsigned)w + j > el && (unsigned)w < el)
j = el - w;
z = 1 << j;
l[h] = j;
if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
(struct huft *)NULL)
{
if (h)
huft_free(u[0]);
return 3;
}
#ifdef DEBUG
G.hufts += z + 1;
#endif
*t = q + 1;
*(t = &(q->v.t)) = (struct huft *)NULL;
u[h] = ++q;
if (h)
{
x[h] = i;
r.b = (uch)l[h-1];
r.e = (uch)(32 + j);
r.v.t = q;
j = (i & ((1 << w) - 1)) >> (w - l[h-1]);
u[h-1][j] = r;
}
}
r.b = (uch)(k - w);
if (p >= v + n)
r.e = INVALID_CODE;
else if (*p < s)
{
r.e = (uch)(*p < 256 ? 32 : 31);
r.v.n = (ush)*p++;
}
else
{
r.e = e[*p - s];
r.v.n = d[*p++ - s];
}
f = 1 << (k - w);
for (j = i >> w; j < z; j += f)
q[j] = r;
for (j = 1 << (k - 1); i & j; j >>= 1)
i ^= j;
i ^= j;
while ((i & ((1 << w) - 1)) != x[h])
w -= l[--h];
}
}
*m = l[0];
return y != 0 && g != 1;
}
int huft_free(t)
struct huft *t;
list of the tables it made, with the links in a dummy first entry of
each table. */
{
register struct huft *p, *q;
p = t;
while (p != (struct huft *)NULL)
{
q = (--p)->v.t;
free((zvoid *)p);
p = q;
}
return 0;
}
