-/* inflate.c -- put in the public domain by Mark Adler */

-

-/* Decompresses raw data compressed using the DEFLATE algorithm (RFC 1951) */

-

-/* 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 inflate() 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

-

- fork 12 Dec 07 Adapted for TrueCrypt

- */

-

-

-/*

- 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

- */

-

-

-/*

- 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.

- */

-

-

-/* #define DEBUG */

-#define INFMOD /* tell inflate.h to include code to be compiled */

-#include "inflate.h"

-

-

-#ifndef WSIZE /* default is 32K */

-# define WSIZE 0x8000 /* window size--must be a power of two, and at least */

-#endif /* 32K for zip's deflate method */

-

-#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 /* default is to simply get a byte from stdin */

-# define NEXTBYTE getchar()

-#endif

-

-#ifndef MESSAGE /* only used twice, for fixed strings--NOT general-purpose */

-# define MESSAGE(str,len,flag) fprintf(stderr,(char *)(str))

-#endif

-

-#ifndef FLUSH /* default is to simply write the buffer to stdout */

-# define FLUSH(n) fwrite(redirSlide, 1, n, stdout) /* return value not used */

-#endif

-/* Warning: the fwrite above might not work on 16-bit compilers, since

- 0x8000 might be interpreted as -32,768 by the library function. */

-

-#ifndef Trace

-# ifdef DEBUG

-# define Trace(x) fprintf x

-# else

-# define Trace(x)

-# endif

-#endif

-

-G_struct G;

-uch redirSlide [WSIZE];

-

-/*---------------------------------------------------------------------------*/

-#ifdef USE_ZLIB

-

-

-/*

- GRR: return values for both original inflate() and inflate()

- 0 OK

- 1 incomplete table(?)

- 2 bad input

- 3 not enough memory

- */

-

-/**************************/

-/* Function inflate() */

-/**************************/

-

-int inflate(__G) /* decompress an inflated entry using the zlib routines */

- __GDEF

-{

- 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;

-

- /* only need to test this stuff once */

- 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));

-

- /* windowBits = log2(wsize) */

- for (i = ((unsigned)wsize * 2 - 1), 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 /* !FUNZIP */

- while (G.csize > 0) {

- Trace((stderr, "first loop: G.csize = %ld\n", G.csize));

-#endif /* ?FUNZIP */

- while (G.dstrm.avail_out > 0) {

- err = inflate(&G.dstrm, Z_PARTIAL_FLUSH);

-

- if (err == Z_DATA_ERROR)

- return 2;

- else if (err == Z_MEM_ERROR)

- return 3;

- 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) /* "END-of-entry-condition" ? */

-#else /* !FUNZIP */

- if (G.csize <= 0L) /* "END-of-entry-condition" ? */

-#endif /* ?FUNZIP */

- break;

-

- if (G.dstrm.avail_in <= 0) {

- if (fillinbuf(__G) == 0)

- return 2; /* no "END-condition" yet, but no more data */

-

- G.dstrm.next_in = G.inptr;

- G.dstrm.avail_in = G.incnt;

- }

- Trace((stderr, " avail_in = %d\n", G.dstrm.avail_in));

- }

- FLUSH(wsize - G.dstrm.avail_out); /* flush slide[] */

- 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;

- }

-

- /* no more input, so loop until we have all output */

- 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)

- return 2;

- else if (err == Z_MEM_ERROR)

- return 3;

- else if (err == Z_BUF_ERROR) { /* DEBUG */

- 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);

- }

- FLUSH(wsize - G.dstrm.avail_out); /* final flush of slide[] */

- 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; /* reset for other routines */

-

- err = inflateReset(&G.dstrm);

- if (err != Z_OK)

- Trace((stderr, "oops! (inflateReset() err = %d)\n", err));

-

- return 0;

-}

-

-

-/*---------------------------------------------------------------------------*/

-#else /* !USE_ZLIB */

-

-

-/* Function prototypes */

-#ifndef OF

-# ifdef __STDC__

-# define OF(a) a

-# else

-# define OF(a) ()

-# endif

-#endif /* !OF */

-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));

-

-

-/* The inflate algorithm uses a sliding 32K byte window on the uncompressed

- 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). */

-/* It is left to other modules to supply the 32K area. It is assumed

- 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. */

-

-

-/* unsigned wp; moved to globals.h */ /* current position in slide */

-

-

-/* Tables for deflate from PKZIP's appnote.txt. */

-static ZCONST unsigned 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};

-static ZCONST ush cplens[] = { /* 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};

- /* note: see note #13 above about the 258 in this list. */

-static ZCONST ush cplext[] = { /* 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, 99, 99}; /* 99==invalid */

-static ZCONST ush cpdist[] = { /* 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 ZCONST ush cpdext[] = { /* 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};

-

-

-/* moved to consts.h (included in unzip.c), resp. funzip.c */

-#if 1

-/* And'ing with mask_bits[n] masks the lower n bits */

-ZCONST ush near mask_bits[] = {

- 0x0000,

- 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,

- 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff

-};

-#endif /* 0 */

-

-

-/* Macros for inflate() bit peeking and grabbing.

- 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.

- */

-

-/* These have been moved to globals.h */

-#if 0

-ulg bb; /* bit buffer */

-unsigned bk; /* bits in bit buffer */

-#endif

-

-#ifndef CHECK_EOF

-# define CHECK_EOF /* default as of 5.13/5.2 */

-#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)return 1;\

- b|=((ulg)c)<<k;k+=8;}}

-#endif /* Piet Plomp: change "return 1" to "break" */

-

-#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; /* bits in base literal/length lookup table */

-static ZCONST int dbits = 6; /* bits in base distance lookup table */

-

-

-#ifndef ASM_INFLATECODES

-

-#pragma warning(disable:4131)

-

-int inflate_codes(__G__ tl, td, bl, bd)

- __GDEF

-struct huft *tl, *td; /* literal/length and distance decoder tables */

-int bl, bd; /* number of bits decoded by tl[] and td[] */

-/* inflate (decompress) the codes in a deflated (compressed) block.

- Return an error code or zero if it all goes ok. */

-{

- register unsigned e; /* table entry flag/number of extra bits */

- unsigned n, d; /* length and index for copy */

- unsigned w; /* current window position */

- struct huft *t; /* pointer to table entry */

- unsigned ml, md; /* masks for bl and bd bits */

- register ulg b; /* bit buffer */

- register unsigned k; /* number of bits in bit buffer */

-

-

- /* make local copies of globals */

- b = G.bb; /* initialize bit buffer */

- k = G.bk;

- w = G.wp; /* initialize window position */

-

-

- /* inflate the coded data */

- ml = mask_bits[bl]; /* precompute masks for speed */

- md = mask_bits[bd];

- while (1) /* do until end of block */

- {

- NEEDBITS((unsigned)bl)

- if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)

- do {

- if (e == 99)

- return 1;

- DUMPBITS(t->b)

- e -= 16;

- NEEDBITS(e)

- } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);

- DUMPBITS(t->b)

- if (e == 16) /* then it's a literal */

- {

- redirSlide[w++] = (uch)t->v.n;

- if (w == wsize)

- {

- FLUSH(w);

- w = 0;

- }

- }

- else /* it's an EOB or a length */

- {

- /* exit if end of block */

- if (e == 15)

- break;

-

- /* get length of block to copy */

- NEEDBITS(e)

- n = t->v.n + ((unsigned)b & mask_bits[e]);

- DUMPBITS(e);

-

- /* decode distance of block to copy */

- NEEDBITS((unsigned)bd)

- if ((e = (t = td + ((unsigned)b & md))->e) > 16)

- do {

- if (e == 99)

- return 1;

- DUMPBITS(t->b)

- e -= 16;

- NEEDBITS(e)

- } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);

- DUMPBITS(t->b)

- NEEDBITS(e)

- d = w - t->v.n - ((unsigned)b & mask_bits[e]);

- DUMPBITS(e)

-

- /* do the copy */

- do {

-#if (defined(DLL) && !defined(NO_SLIDE_REDIR))

- if (G.redirect_slide) {/* &= w/ wsize unnecessary & wrong if redirect */

- if (d >= wsize)

- return 1; /* invalid compressed data */

- n -= (e = (e = wsize - (d > w ? d : w)) > n ? n : e);

- }

- else

-#endif

- n -= (e = (e = wsize - ((d &= wsize-1) > w ? d : w)) > n ? n : e);

-#ifndef NOMEMCPY

- if (w - d >= e) /* (this test assumes unsigned comparison) */

- {

- memcpy(redirSlide + w, redirSlide + d, e);

- w += e;

- d += e;

- }

- else /* do it slowly to avoid memcpy() overlap */

-#endif /* !NOMEMCPY */

- do {

- redirSlide[w++] = redirSlide[d++];

- } while (--e);

- if (w == wsize)

- {

- FLUSH(w);

- w = 0;

- }

- } while (n);

- }

- }

-

-

- /* restore the globals from the locals */

- G.wp = w; /* restore global window pointer */

- G.bb = b; /* restore global bit buffer */

- G.bk = k;

-

-

- /* done */

- return 0;

-}

-

-#endif /* ASM_INFLATECODES */

-

-

-

-static int inflate_stored(__G)

- __GDEF

-/* "decompress" an inflated type 0 (stored) block. */

-{

- unsigned n; /* number of bytes in block */

- unsigned w; /* current window position */

- register ulg b; /* bit buffer */

- register unsigned k; /* number of bits in bit buffer */

-

-

- /* make local copies of globals */

- Trace((stderr, "\nstored block"));

- b = G.bb; /* initialize bit buffer */

- k = G.bk;

- w = G.wp; /* initialize window position */

-

-

- /* go to byte boundary */

- n = k & 7;

- DUMPBITS(n);

-

-

- /* get the length and its complement */

- NEEDBITS(16)

- n = ((unsigned)b & 0xffff);

- DUMPBITS(16)

- NEEDBITS(16)

- if (n != (unsigned)((~b) & 0xffff))

- return 1; /* error in compressed data */

- DUMPBITS(16)

-

-

- /* read and output the compressed data */

- while (n--)

- {

- NEEDBITS(8)

- redirSlide[w++] = (uch)b;

- if (w == wsize)

- {

- FLUSH(w);

- w = 0;

- }

- DUMPBITS(8)

- }

-

-

- /* restore the globals from the locals */

- G.wp = w; /* restore global window pointer */

- G.bb = b; /* restore global bit buffer */

- G.bk = k;

- return 0;

-}

-

-

-/* Globals for literal tables (built once) */

-/* Moved to globals.h */

-#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

-/* decompress an inflated type 1 (fixed Huffman codes) block. We should

- either replace this with a custom decoder, or at least precompute the

- Huffman tables. */

-{

- /* if first time, set up tables for fixed blocks */

- Trace((stderr, "\nliteral block"));

- if (G.fixed_tl == (struct huft *)NULL)

- {

- int i; /* temporary variable */

- unsigned l[288]; /* length list for huft_build */

-

- /* 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;

- G.fixed_bl = 7;

- if ((i = huft_build(__G__ l, 288, 257, cplens, cplext,

- &G.fixed_tl, &G.fixed_bl)) != 0)

- {

- G.fixed_tl = (struct huft *)NULL;

- return i;

- }

-

- /* distance table */

- for (i = 0; i < 30; i++) /* make an incomplete code set */

- l[i] = 5;

- G.fixed_bd = 5;

- if ((i = huft_build(__G__ l, 30, 0, cpdist, cpdext,

- &G.fixed_td, &G.fixed_bd)) > 1)

- {

- huft_free(G.fixed_tl);

- G.fixed_tl = (struct huft *)NULL;

- return i;

- }

- }

-

- /* decompress until an end-of-block code */

- return inflate_codes(__G__ G.fixed_tl, G.fixed_td,

- G.fixed_bl, G.fixed_bd) != 0;

-}

-

-

-

-static int inflate_dynamic(__G)

- __GDEF

-/* decompress an inflated type 2 (dynamic Huffman codes) block. */

-{

- int i; /* temporary variables */

- unsigned j;

- unsigned l; /* last length */

- unsigned m; /* mask for bit lengths table */

- unsigned n; /* number of lengths to get */

- struct huft *tl; /* literal/length code table */

- struct huft *td; /* distance code table */

- int bl; /* lookup bits for tl */

- int bd; /* lookup bits for td */

- unsigned nb; /* number of bit length codes */

- unsigned nl; /* number of literal/length codes */

- unsigned nd; /* number of distance codes */

-#ifdef PKZIP_BUG_WORKAROUND

- unsigned ll[288+32]; /* literal/length and distance code lengths */

-#else

- unsigned ll[286+30]; /* literal/length and distance code lengths */

-#endif

- register ulg b; /* bit buffer */

- register unsigned k; /* number of bits in bit buffer */

-

-

- /* make local bit buffer */

- Trace((stderr, "\ndynamic block"));

- b = G.bb;

- k = G.bk;

-

-

- /* read in table lengths */

- NEEDBITS(5)

- nl = 257 + ((unsigned)b & 0x1f); /* number of literal/length codes */

- DUMPBITS(5)

- NEEDBITS(5)

- nd = 1 + ((unsigned)b & 0x1f); /* number of distance codes */

- DUMPBITS(5)

- NEEDBITS(4)

- nb = 4 + ((unsigned)b & 0xf); /* number of bit length codes */

- DUMPBITS(4)

-#ifdef PKZIP_BUG_WORKAROUND

- if (nl > 288 || nd > 32)

-#else

- if (nl > 286 || nd > 30)

-#endif

- return 1; /* bad lengths */

-

-

- /* read in bit-length-code lengths */

- for (j = 0; j < nb; j++)

- {

- NEEDBITS(3)

- ll[border[j]] = (unsigned)b & 7;

- DUMPBITS(3)

- }

- for (; j < 19; j++)

- ll[border[j]] = 0;

-

-

- /* build decoding table for trees--single level, 7 bit lookup */

- bl = 7;

- i = huft_build(__G__ ll, 19, 19, NULL, NULL, &tl, &bl);

- if (bl == 0) /* no bit lengths */

- i = 1;

- if (i)

- {

- if (i == 1)

- huft_free(tl);

- return i; /* incomplete code set */

- }

-

-

- /* read in literal and distance code lengths */

- 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) /* length of code in bits (0..15) */

- ll[i++] = l = j; /* save last length in l */

- else if (j == 16) /* repeat last length 3 to 6 times */

- {

- NEEDBITS(2)

- j = 3 + ((unsigned)b & 3);

- DUMPBITS(2)

- if ((unsigned)i + j > n)

- {

- huft_free(tl);

- return 1;

- }

- while (j--)

- ll[i++] = l;

- }

- else if (j == 17) /* 3 to 10 zero length codes */

- {

- NEEDBITS(3)

- j = 3 + ((unsigned)b & 7);

- DUMPBITS(3)

- if ((unsigned)i + j > n)

- {

- huft_free(tl);

- return 1;

- }

- while (j--)

- ll[i++] = 0;

- l = 0;

- }

- else /* j == 18: 11 to 138 zero length codes */

- {

- NEEDBITS(7)

- j = 11 + ((unsigned)b & 0x7f);

- DUMPBITS(7)

- if ((unsigned)i + j > n)

- {

- huft_free(tl);

- return 1;

- }

- while (j--)

- ll[i++] = 0;

- l = 0;

- }

- }

-

-

- /* free decoding table for trees */

- huft_free(tl);

-

-

- /* restore the global bit buffer */

- G.bb = b;

- G.bk = k;

-

-

- /* build the decoding tables for literal/length and distance codes */

- bl = lbits;

- i = huft_build(__G__ ll, nl, 257, cplens, cplext, &tl, &bl);

- if (bl == 0) /* no literals or lengths */

- i = 1;

- if (i)

- {

- if (i == 1) {

- //if (!uO.qflag)

- MESSAGE((uch *)"(incomplete l-tree) ", 21L, 1);

- huft_free(tl);

- }

- return i; /* incomplete code set */

- }

- bd = dbits;

- i = huft_build(__G__ ll + nl, nd, 0, cpdist, cpdext, &td, &bd);

- if (bd == 0 && nl > 257) /* lengths but no distances */

- {

- //if (!uO.qflag)

- MESSAGE((uch *)"(incomplete d-tree) ", 21L, 1);

- huft_free(tl);

- huft_free(td);

- return 1;

- }

- if (i == 1) {

-#ifdef PKZIP_BUG_WORKAROUND

- i = 0;

-#else

- //if (!uO.qflag)

- MESSAGE((uch *)"(incomplete d-tree) ", 21L, 1);

- huft_free(td);

- td = NULL;

-#endif

- }

- if (i)

- {

- huft_free(tl);

- return i;

- }

-

-

- /* decompress until an end-of-block code */

- i = inflate_codes(__G__ tl, td, bl, bd);

-

- /* free the decoding tables, return */

- huft_free(tl);

- huft_free(td);

-

- if (i)

- return 1;

-

- return 0;

-}

-

-

-

-static int inflate_block(__G__ e)

- __GDEF

- int *e; /* last block flag */

-/* decompress an inflated block */

-{

- unsigned t; /* block type */

- register ulg b; /* bit buffer */

- register unsigned k; /* number of bits in bit buffer */

-

-

- /* make local bit buffer */

- b = G.bb;

- k = G.bk;

-

-

- /* read in last block bit */

- NEEDBITS(1)

- *e = (int)b & 1;

- DUMPBITS(1)

-

-

- /* read in block type */

- NEEDBITS(2)

- t = (unsigned)b & 3;

- DUMPBITS(2)

-

-

- /* restore the global bit buffer */

- G.bb = b;

- G.bk = k;

-

-

- /* inflate that block type */

- if (t == 2)

- return inflate_dynamic(__G);

- if (t == 0)

- return inflate_stored(__G);

- if (t == 1)

- return inflate_fixed(__G);

-

-

- /* bad block type */

- return 2;

-}

-

-

-

-int inflate(__G)

- __GDEF

-/* decompress an inflated entry */

-{

- int e; /* last block flag */

- int r; /* result code */

-//#ifdef DEBUG

-// unsigned h = 0; /* maximum struct huft's malloc'ed */

-//#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; /* how they're #defined if !DLL */

-#endif

-

- /* initialize window, bit buffer */

- G.wp = 0;

- G.bk = 0;

- G.bb = 0;

-

-

- /* decompress until the last block */

- 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);

-

-

- /* flush out redirSlide */

- FLUSH(G.wp);

-

-

- /* return success */

- //Trace((stderr, "\n%u bytes in Huffman tables (%d/entry)\n",

- // h * sizeof(struct huft), sizeof(struct huft)));

- return 0;

-}

-

-

-

-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 /* ?USE_ZLIB */

-

-

-/*

- * GRR: moved huft_build() and huft_free() down here; used by explode()

- * and fUnZip regardless of whether USE_ZLIB defined or not

- */

-

-

-/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */

-#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(

- __GDEF

- ZCONST unsigned *b, /* code lengths in bits (all assumed <= BMAX) */

- unsigned n, /* number of codes (assumed <= N_MAX) */

- unsigned s, /* number of simple-valued codes (0..s-1) */

- ZCONST ush *d, /* list of base values for non-simple codes */

- ZCONST ush *e, /* list of extra bits for non-simple codes */

- struct huft **t, /* result: starting table */

- int *m /* maximum lookup bits, returns actual */

- )

-/* Given a list of code lengths and a maximum table size, make a set of

- 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; /* counter for codes of length k */

- unsigned c[BMAX+1]; /* bit length count table */

- unsigned el; /* length of EOB code (value 256) */

- unsigned f; /* i repeats in table every f entries */

- int g; /* maximum code length */

- int h; /* table level */

- register unsigned i; /* counter, current code */

- register unsigned j; /* counter */

- register int k; /* number of bits in current code */

- int lx[BMAX+1]; /* memory for l[-1..BMAX-1] */

- int *l = lx+1; /* stack of bits per table */

- register unsigned *p; /* pointer into c[], b[], or v[] */

- register struct huft *q; /* points to current table */

- struct huft r; /* table entry for structure assignment */

- struct huft *u[BMAX]; /* table stack */

- unsigned v[N_MAX]; /* values in order of bit length */

- register int w; /* bits before this table == (l * h) */

- unsigned x[BMAX+1]; /* bit offsets, then code stack */

- unsigned *xp; /* pointer into x */

- int y; /* number of dummy codes added */

- unsigned z; /* number of entries in current table */

-

-

- /* Generate counts for each bit length */

- el = n > 256 ? b[256] : BMAX; /* set length of EOB code, if any */

- memset(c, 0, sizeof(c));

- p = (unsigned *)b; i = n;

- do {

- c[*p]++; p++; /* assume all entries <= BMAX */

- } while (--i);

- if (c[0] == n) /* null input--all zero length codes */

- {

- *t = (struct huft *)NULL;

- *m = 0;

- return 0;

- }

-

-

- /* Find minimum and maximum length, bound *m by those */

- for (j = 1; j <= BMAX; j++)

- if (c[j])

- break;

- k = j; /* minimum code length */

- if ((unsigned)*m < j)

- *m = j;

- for (i = BMAX; i; i--)

- if (c[i])

- break;

- g = i; /* maximum code length */

- if ((unsigned)*m > i)

- *m = i;

-

-

- /* 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 2; /* bad input: more codes than bits */

- if ((y -= c[i]) < 0)

- return 2;

- c[i] += y;

-

-

- /* 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++);

- }

-

-

- /* Make a table of values in order of bit lengths */

- memset(v, 0, sizeof(v));

- p = (unsigned *)b; i = 0;

- do {

- if ((j = *p++) != 0)

- v[x[j]++] = i;

- } while (++i < n);

- n = x[g]; /* set n to length of v */

-

-

- /* 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[-1] = 0; /* no bits decoded yet */

- u[0] = (struct huft *)NULL; /* just to keep compilers happy */

- q = (struct huft *)NULL; /* ditto */

- z = 0; /* ditto */

-

- /* 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[h++]; /* add bits already decoded */

-

- /* compute minimum size table less than or equal to *m bits */

- z = (z = g - w) > (unsigned)*m ? *m : z; /* 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;

- 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 */

- }

- }

- if ((unsigned)w + j > el && (unsigned)w < el)

- j = el - w; /* make EOB code end at table */

- z = 1 << j; /* table entries for j-bit table */

- l[h] = j; /* set table size in stack */

-

- /* allocate and link in new table */

- if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==

- (struct huft *)NULL)

- {

- if (h)

- huft_free(u[0]);

- return 3; /* not enough memory */

- }

-//#ifdef DEBUG

-// G.hufts += z + 1; /* track memory usage */

-//#endif

- *t = q + 1; /* link to list for huft_free() */

- *(t = &(q->v.t)) = (struct huft *)NULL;

- u[h] = ++q; /* table starts after link */

-

- /* connect to last table, if there is one */

- if (h)

- {

- x[h] = i; /* save pattern for backing up */

- r.b = (uch)l[h-1]; /* bits to dump before this table */

- r.e = (uch)(16 + j); /* bits in this table */

- r.v.t = q; /* pointer to this table */

- j = (i & ((1 << w) - 1)) >> (w - l[h-1]);

- u[h-1][j] = r; /* connect to last table */

- }

- }

-

- /* set up table entry in r */

- r.b = (uch)(k - w);

- if (p >= v + n)

- r.e = 99; /* out of values--invalid code */

- else if (*p < s)

- {

- r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */

- r.v.n = (ush)*p++; /* simple code is just the value */

- }

- else

- {

- r.e = (uch)e[*p - s]; /* non-simple--look up in lists */

- r.v.n = d[*p++ - s];

- }

-

- /* fill code-like entries with r */

- f = 1 << (k - w);

- for (j = i >> w; j < z; j += f)

- q[j] = r;

-

- /* backwards increment the k-bit code i */

- for (j = 1 << (k - 1); i & j; j >>= 1)

- i ^= j;

- i ^= j;

-

- /* backup over finished tables */

- while ((i & ((1 << w) - 1)) != x[h])

- w -= l[--h]; /* don't need to update q */

- }

- }

-

-

- /* return actual size of base table */

- *m = l[0];

-

-

- /* Return true (1) if we were given an incomplete table */

- return y != 0 && g != 1;

-}

-

-

-

-int huft_free (struct huft *t)

- /* table to free */

-/* Free the malloc'ed tables built by huft_build(), which makes a linked

- list of the tables it made, with the links in a dummy first entry of

- each table. */

-{

- register struct huft *p, *q;

-

-

- /* Go through linked list, freeing from the malloced (t[-1]) address. */

- p = t;

- while (p != (struct huft *)NULL)

- {

- q = (--p)->v.t;

- free((zvoid *)p);

- p = q;

- }

- return 0;

-}

-

-

-// Main public function. Decompresses raw data compressed using the DEFLATE algorithm (RFC 1951 - e.g. zlib, gzip).

-// Returns 0 if decompression fails or, if successful, returns the size of the decompressed data.

-int DecompressDeflatedData (char *out, char *in, int inLength)

-{

- G.outbufptr = out;

- G.inptr = in;

- G.incnt = inLength;

- G.outCounter = 0;

-

- if (inflate(__G) != 0)

- {

- // Error decompressing

- return 0;

- }

- return G.outCounter;

-}

-