ref: d34ddd8775ca8ebad64222911e5dd60069918b54
dir: /inflate.c/
/*
* inflate.c - inflate decompression routine
*
* Version 1.1
*/
/*
* Copyright (c) 1995, Edward B. Hamrick
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that
*
* (i) the above copyright notice and the text in this "C" comment block
* appear in all copies of the software and related documentation, and
*
* (ii) any modifications to this source file must be sent, via e-mail
* to the copyright owner (currently hamrick@primenet.com) within
* 30 days of such modification.
*
* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL EDWARD B. HAMRICK BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF
* THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* inflate.c is based on the public-domain (non-copyrighted) version
* written by Mark Adler, version c14o, 23 August 1994. It has been
* modified to be reentrant, more portable, and to be data driven.
*/
/*
* 1) All file i/o is done externally to these routines
* 2) Routines are symmetrical so inflate can feed into deflate
* 3) Routines can be easily integrated into wide range of applications
* 4) Routines are very portable, and use only ANSI C
* 5) No #defines in inflate.h to conflict with external #defines
* 6) No external routines need be called by these routines
* 7) Buffers are owned by the calling routine
* 8) No static non-constant variables are allowed
*/
/*
* Note that for each call to InflatePutBuffer, there will be
* 0 or more calls to (*putbuffer_ptr). Before InflatePutBuffer
* returns, it will have output as much uncompressed data as
* is possible.
*/
#ifdef MEMCPY
#include <mem.h>
#endif
#include "inflate.h"
/*
* Macros for constants
*/
#ifndef NULL
#define NULL ((void *) 0)
#endif
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif
#ifndef WINDOWSIZE
#define WINDOWSIZE 0x8000
#endif
#ifndef WINDOWMASK
#define WINDOWMASK 0x7fff
#endif
#ifndef BUFFERSIZE
#define BUFFERSIZE 0x4000
#endif
#ifndef BUFFERMASK
#define BUFFERMASK 0x3fff
#endif
#ifndef INFLATESTATETYPE
#define INFLATESTATETYPE 0xabcdabcdL
#endif
/*
* typedefs
*/
typedef unsigned long ulg;
typedef unsigned short ush;
typedef unsigned char uch;
/* Structure to hold state for inflating zip files */
struct InflateState {
unsigned long runtimetypeid1; /* to detect run-time errors */
int errorencountered; /* error encountered flag */
/* Decoding state */
int state; /* -1 -> need block type */
/* 0 -> need stored setup */
/* 1 -> need fixed setup */
/* 2 -> need dynamic setup */
/* 10 -> need stored data */
/* 11 -> need fixed data */
/* 12 -> need dynamic data */
/* State for decoding fixed & dynamic data */
struct huft *tl; /* literal/length decoder tbl */
struct huft *td; /* distance decoder table */
int bl; /* bits decoded by tl */
int bd; /* bits decoded by td */
/* State for decoding stored data */
unsigned int storelength;
/* State to keep track that last block has been encountered */
int lastblock; /* current block is last */
/* Input buffer state (circular) */
ulg bb; /* input buffer bits */
unsigned int bk; /* input buffer count of bits */
unsigned int bp; /* input buffer pointer */
unsigned int bs; /* input buffer size */
unsigned char buffer[BUFFERSIZE]; /* input buffer data */
/* Storage for try/catch */
ulg catch_bb; /* bit buffer */
unsigned int catch_bk; /* bits in bit buffer */
unsigned int catch_bp; /* buffer pointer */
unsigned int catch_bs; /* buffer size */
/* Output window state (circular) */
unsigned int wp; /* output window pointer */
unsigned int wf; /* output window flush-from */
unsigned char window[WINDOWSIZE]; /* output window data */
/* Application state */
void *AppState; /* opaque ptr for callout */
/* pointers to call-outs */
int (*putbuffer_ptr)( /* returns 0 on success */
void *AppState, /* opaque ptr from Initialize */
unsigned char *buffer, /* buffer to put */
long length /* length of buffer */
);
void *(*malloc_ptr)(long length); /* utility routine */
void (*free_ptr)(void *buffer); /* utility routine */
unsigned long runtimetypeid2; /* to detect run-time errors */
};
/*
* Error handling macro
*/
#define ERROREXIT(is) {(is)->errorencountered = TRUE; return TRUE;}
/*
* Macros for handling data in the input buffer
*
* Note that the NEEDBITS and DUMPBITS macros
* need to be bracketed by the TRY/CATCH macros
*
* The usage is:
*
* TRY
* {
* NEEDBITS(j)
* x = b & mask_bits[j];
* DUMPBITS(j)
* }
* CATCH_BEGIN
* cleanup code
* CATCH_END
*
* Note that there can only be one TRY/CATCH pair per routine
* because of the use of goto in the implementation of the macros.
*
* 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 beginning 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.
*/
#define TRY \
is->catch_bb = b; \
is->catch_bk = k; \
is->catch_bp = is->bp; \
is->catch_bs = is->bs;
#define CATCH_BEGIN \
goto cleanup_done; \
cleanup: \
b = is->catch_bb; \
k = is->catch_bk; \
is->bb = b; \
is->bk = k; \
is->bp = is->catch_bp; \
is->bs = is->catch_bs;
#define CATCH_END \
cleanup_done: ;
#define NEEDBITS(n) \
{ \
while (k < (n)) \
{ \
if (is->bs <= 0) \
{ \
goto cleanup; \
} \
b |= ((ulg) (is->buffer[is->bp & BUFFERMASK])) << k; \
is->bs--; \
is->bp++; \
k += 8; \
} \
}
#define DUMPBITS(n) \
{ \
b >>= (n); \
k -= (n); \
}
/*
* Macro for flushing the output window to the putbuffer callout.
*
* Note that the window is always flushed when it fills to 32K,
* and before returning to the application.
*/
#define FLUSHWINDOW(w, now) \
if ((now && (is->wp > is->wf)) || ((w) >= WINDOWSIZE)) \
{ \
is->wp = (w); \
if ((*(is->putbuffer_ptr)) \
(is->AppState, is->window+is->wf, is->wp-is->wf)) \
ERROREXIT(is); \
is->wp &= WINDOWMASK; \
is->wf = is->wp; \
(w) = is->wp; \
}
/*
* 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 is compressible, then either the fixed or dynamic methods
* are used. In the dynamic method, the compressed data is 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 mutli-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.
*/
/*
* 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. Similarly, 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.
*/
/*
* 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).
* Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
* means that v is a literal, 16 < e < 32 means that v is a pointer to
* the next table, which codes e - 16 bits, and lastly e == 99 indicates
* an unused code. If a code with e == 99 is looked up, this implies an
* error in the data.
*/
struct huft {
uch e; /* number of extra bits or operation */
uch b; /* number of bits in this code or subcode */
union {
ush n; /* literal, length base, or distance base */
struct huft *t; /* pointer to next level of table */
} v;
};
/*
* Tables for deflate from PKZIP's appnote.txt.
*/
static const 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 const 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 const 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 const 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 const 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};
/*
* Constants for run-time computation of mask
*/
static const ush mask_bits[] = {
0x0000,
0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
};
/*
* 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.
*/
static const int lbits = 9; /* bits in base literal/length lookup table */
static const int dbits = 6; /* bits in base distance lookup table */
/* 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 */
/*
* 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.
*/
static int huft_free(
struct InflateState *is, /* Inflate state */
struct huft *t /* table to free */
)
{
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;
(*is->free_ptr)((char*)p);
p = q;
}
return 0;
}
/*
* 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.
*/
static int huft_build(
struct InflateState *is, /* Inflate state */
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) */
const ush *d, /* list of base values for non-simple codes */
const ush *e, /* list of extra bits for non-simple codes */
struct huft **t, /* result: starting table */
int *m /* maximum lookup bits, returns actual */
)
{
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 */
unsigned i; /* counter, current code */
unsigned j; /* counter */
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 */
unsigned *p; /* pointer into c[], b[], or v[] */
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 */
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 */
/* clear the bit length count table */
for (i=0; i<(BMAX+1); i++)
{
c[i] = 0;
}
/* Generate counts for each bit length */
el = n > 256 ? b[256] : BMAX; /* set length of EOB code, if any */
p = 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 */
p = b; i = 0;
do {
if ((j = *p++) != 0)
v[x[j]++] = i;
} while (++i < n);
/* 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 *)
((*is->malloc_ptr)((z + 1)*sizeof(struct huft)))) ==
(struct huft *)NULL)
{
if (h)
huft_free(is, u[0]);
return 3; /* not enough memory */
}
*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;
}
/*
* inflate (decompress) the codes in a stored (uncompressed) block.
* Return an error code or zero if it all goes ok.
*/
static int inflate_stored(
struct InflateState *is /* Inflate state */
)
{
ulg b; /* bit buffer */
unsigned k; /* number of bits in bit buffer */
unsigned w; /* current window position */
/* make local copies of state */
b = is->bb; /* initialize bit buffer */
k = is->bk; /* initialize bit count */
w = is->wp; /* initialize window position */
/*
* Note that this code knows that NEEDBITS jumps to cleanup
*/
while (is->storelength > 0) /* do until end of block */
{
NEEDBITS(8)
is->window[w++] = (uch) b;
DUMPBITS(8)
FLUSHWINDOW(w, FALSE);
is->storelength--;
}
cleanup:
/* restore the state from the locals */
is->bb = b; /* restore bit buffer */
is->bk = k; /* restore bit count */
is->wp = w; /* restore window pointer */
if (is->storelength > 0)
return -1;
else
return 0;
}
static int inflate_codes(
struct InflateState *is, /* Inflate state */
struct huft *tl, /* literal/length decoder table */
struct huft *td, /* distance decoder table */
int bl, /* number of bits decoded by tl[] */
int bd /* number of bits decoded by td[] */
)
{
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 */
ulg b; /* bit buffer */
unsigned k; /* number of bits in bit buffer */
/* make local copies of state */
b = is->bb; /* initialize bit buffer */
k = is->bk; /* initialize bit count */
w = is->wp; /* initialize window position */
/* inflate the coded data */
ml = mask_bits[bl]; /* precompute masks for speed */
md = mask_bits[bd];
for (;;) /* do until end of block */
{
TRY
{
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) /* it's a literal */
{
is->window[w++] = (uch)t->v.n;
FLUSHWINDOW(w, FALSE);
}
else if (e == 15) /* it's an EOB */
{
break;
}
else /* it's a length */
{
/* 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 {
n -= (e = ((e = WINDOWSIZE - ((d &= WINDOWMASK) > w ? d : w)) > n)
? n : e
);
#ifdef MEMCPY
if (w - d >= e) /* (this test assumes unsigned comparison) */
{
memcpy(is->window + w, is->window + d, e);
w += e;
d += e;
}
else /* do it slow to avoid memcpy() overlap */
#endif /* MEMCPY */
do {
is->window[w++] = is->window[d++];
} while (--e);
FLUSHWINDOW(w, FALSE);
} while (n);
}
}
CATCH_BEGIN
is->wp = w; /* restore window pointer */
return -1;
CATCH_END
}
/* restore the state from the locals */
is->bb = b; /* restore bit buffer */
is->bk = k; /* restore bit count */
is->wp = w; /* restore window pointer */
/* done */
return 0;
}
/*
* "decompress" an inflated type 0 (stored) block.
*/
static int inflate_stored_setup(
struct InflateState *is /* Inflate state */
)
{
unsigned n; /* number of bytes in block */
ulg b; /* bit buffer */
unsigned k; /* number of bits in bit buffer */
/* make local copies of state */
b = is->bb; /* initialize bit buffer */
k = is->bk; /* initialize bit count */
TRY
{
/* 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)
}
CATCH_BEGIN
return -1;
CATCH_END
/* Save store state for this block */
is->storelength = n;
/* restore the state from the locals */
is->bb = b; /* restore bit buffer */
is->bk = k; /* restore bit count */
return 0;
}
/*
* 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.
*/
static int inflate_fixed_setup(
struct InflateState *is /* Inflate state */
)
{
int i; /* temporary variable */
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 l[288]; /* length list 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 = 7;
if ((i = huft_build(is, l, 288, 257, cplens, cplext, &tl, &bl)) != 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(is, l, 30, 0, cpdist, cpdext, &td, &bd)) > 1)
{
huft_free(is, tl);
return i;
}
/* Save inflate state for this block */
is->tl = tl;
is->td = td;
is->bl = bl;
is->bd = bd;
return 0;
}
/*
* decompress an inflated type 2 (dynamic Huffman codes) block.
*/
#define PKZIP_BUG_WORKAROUND
static int inflate_dynamic_setup(
struct InflateState *is /* Inflate state */
)
{
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
ulg b; /* bit buffer */
unsigned k; /* number of bits in bit buffer */
/* make local copies of state */
b = is->bb; /* initialize bit buffer */
k = is->bk; /* initialize bit count */
/* initialize tl for cleanup */
tl = NULL;
TRY
{
/* 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 < 19; j++) ll[j] = 0;
for (j = 0; j < nb; j++)
{
NEEDBITS(3)
ll[border[j]] = (unsigned)b & 7;
DUMPBITS(3)
}
/* build decoding table for trees--single level, 7 bit lookup */
bl = 7;
if ((i = huft_build(is, ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
{
if (i == 1)
huft_free(is, 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)
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)
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)
return 1;
while (j--)
ll[i++] = 0;
l = 0;
}
}
/* free decoding table for trees */
huft_free(is, tl);
}
CATCH_BEGIN
if (tl) huft_free(is, tl);
return -1;
CATCH_END
/* restore the state from the locals */
is->bb = b; /* restore bit buffer */
is->bk = k; /* restore bit count */
/* build the decoding tables for literal/length and distance codes */
bl = lbits;
if ((i = huft_build(is, ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
{
if (i == 1) {
/* incomplete literal tree */
huft_free(is, tl);
}
return i; /* incomplete code set */
}
bd = dbits;
if ((i = huft_build(is, ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
{
if (i == 1) {
/* incomplete distance tree */
#ifdef PKZIP_BUG_WORKAROUND
}
#else
huft_free(is, td);
}
huft_free(is, tl);
return i; /* incomplete code set */
#endif
}
/* Save inflate state for this block */
is->tl = tl;
is->td = td;
is->bl = bl;
is->bd = bd;
return 0;
}
/* Routine to initialize inflate decompression */
void *InflateInitialize( /* returns InflateState */
void *AppState, /* for passing to putbuffer */
int (*putbuffer_ptr)( /* returns 0 on success */
void *AppState, /* opaque ptr from Initialize */
unsigned char *buffer, /* buffer to put */
long length /* length of buffer */
),
void *(*malloc_ptr)(long length), /* utility routine */
void (*free_ptr)(void *buffer) /* utility routine */
)
{
struct InflateState *is;
/* Do some argument checking */
if ((!putbuffer_ptr) || (!malloc_ptr) || (!free_ptr)) return NULL;
/* Allocate the InflateState memory area */
is = (struct InflateState *) (*malloc_ptr)(sizeof(struct InflateState));
if (!is) return NULL;
/* Set up the initial values of the inflate state */
is->runtimetypeid1 = INFLATESTATETYPE;
is->errorencountered = FALSE;
is->bb = 0;
is->bk = 0;
is->bp = 0;
is->bs = 0;
is->wp = 0;
is->wf = 0;
is->state = -1;
is->lastblock = FALSE;
is->AppState = AppState;
is->putbuffer_ptr = putbuffer_ptr;
is->malloc_ptr = malloc_ptr;
is->free_ptr = free_ptr;
is->runtimetypeid2 = INFLATESTATETYPE;
/* Return this state info to the caller */
return is;
}
/* Call-in routine to put a buffer into inflate decompression */
int InflatePutBuffer( /* returns 0 on success */
void *InflateState, /* opaque ptr from Initialize */
unsigned char *buffer, /* buffer to put */
long length /* length of buffer */
)
{
struct InflateState *is;
int beginstate;
/* Get (and check) the InflateState structure */
is = (struct InflateState *) InflateState;
if (!is || (is->runtimetypeid1 != INFLATESTATETYPE)
|| (is->runtimetypeid2 != INFLATESTATETYPE)) return TRUE;
if (is->errorencountered) return TRUE;
do
{
int size, i;
if ((is->state == -1) && (is->lastblock)) break;
/* Save the beginning state */
beginstate = is->state;
/* Push as much as possible into input buffer */
size = BUFFERSIZE - is->bs;
if (size > length) size = (int) length;
i = is->bp + is->bs;
while (size-- > 0)
{
is->buffer[i++ & BUFFERMASK] = *buffer;
is->bs++;
buffer++;
length--;
}
/* Process some more data */
if (is->state == -1)
{
int e; /* last block flag */
unsigned t; /* block type */
ulg b; /* bit buffer */
unsigned k; /* number of bits in bit buffer */
/* make local copies of state */
b = is->bb; /* initialize bit buffer */
k = is->bk; /* initialize bit count */
TRY
{
/* 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)
if (t <= 2)
{
is->state = t;
is->lastblock = e;
}
else
{
ERROREXIT(is);
}
}
CATCH_BEGIN
CATCH_END
/* restore the state from the locals */
is->bb = b; /* restore bit buffer */
is->bk = k; /* restore bit count */
}
else if (is->state == 0)
{
int ret;
ret = inflate_stored_setup(is);
if (ret > 0)
ERROREXIT(is);
if (ret == 0) is->state += 10;
}
else if (is->state == 1)
{
int ret;
ret = inflate_fixed_setup(is);
if (ret > 0)
ERROREXIT(is);
if (ret == 0) is->state += 10;
}
else if (is->state == 2)
{
int ret;
ret = inflate_dynamic_setup(is);
if (ret > 0)
ERROREXIT(is);
if (ret == 0) is->state += 10;
}
else if (is->state == 10)
{
int ret;
ret = inflate_stored(is);
if (ret > 0)
ERROREXIT(is);
if (ret == 0)
{
is->state = -1;
}
}
else if ((is->state == 11) ||
(is->state == 12) )
{
int ret;
ret = inflate_codes(is, is->tl, is->td, is->bl, is->bd);
if (ret > 0)
ERROREXIT(is);
if (ret == 0)
{
/* free the decoding tables */
huft_free(is, is->tl);
huft_free(is, is->td);
is->state = -1;
}
}
else
{
ERROREXIT(is);
}
}
while (length || (is->state != beginstate));
FLUSHWINDOW(is->wp, TRUE);
return is->errorencountered;
}
/* Routine to terminate inflate decompression */
int InflateTerminate( /* returns 0 on success */
void *InflateState /* opaque ptr from Initialize */
)
{
int err;
void (*free_ptr)(void *buffer);
struct InflateState *is;
/* Get (and check) the InflateState structure */
is = (struct InflateState *) InflateState;
if (!is || (is->runtimetypeid1 != INFLATESTATETYPE)
|| (is->runtimetypeid2 != INFLATESTATETYPE)) return TRUE;
/* save the error return */
err = is->errorencountered || (is->bs > 0)
|| (is->state != -1)
|| (!is->lastblock);
/* save the address of the free routine */
free_ptr = is->free_ptr;
/* Deallocate everything */
(*free_ptr)(is);
return err;
}