inflate.c
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Visual C++
- /* inflate.c -- zlib decompression
- * Copyright (C) 1995-2003 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
- /*
- * Change history:
- *
- * 1.2.beta0 24 Nov 2002
- * - First version -- complete rewrite of inflate to simplify code, avoid
- * creation of window when not needed, minimize use of window when it is
- * needed, make inffast.c even faster, implement gzip decoding, and to
- * improve code readability and style over the previous zlib inflate code
- *
- * 1.2.beta1 25 Nov 2002
- * - Use pointers for available input and output checking in inffast.c
- * - Remove input and output counters in inffast.c
- * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
- * - Remove unnecessary second byte pull from length extra in inffast.c
- * - Unroll direct copy to three copies per loop in inffast.c
- *
- * 1.2.beta2 4 Dec 2002
- * - Change external routine names to reduce potential conflicts
- * - Correct filename to inffixed.h for fixed tables in inflate.c
- * - Make hbuf[] unsigned char to match parameter type in inflate.c
- * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
- * to avoid negation problem on Alphas (64 bit) in inflate.c
- *
- * 1.2.beta3 22 Dec 2002
- * - Add comments on state->bits assertion in inffast.c
- * - Add comments on op field in inftrees.h
- * - Fix bug in reuse of allocated window after inflateReset()
- * - Remove bit fields--back to byte structure for speed
- * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
- * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
- * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
- * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
- * - Use local copies of stream next and avail values, as well as local bit
- * buffer and bit count in inflate()--for speed when inflate_fast() not used
- *
- * 1.2.beta4 1 Jan 2003
- * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
- * - Move a comment on output buffer sizes from inffast.c to inflate.c
- * - Add comments in inffast.c to introduce the inflate_fast() routine
- * - Rearrange window copies in inflate_fast() for speed and simplification
- * - Unroll last copy for window match in inflate_fast()
- * - Use local copies of window variables in inflate_fast() for speed
- * - Pull out common write == 0 case for speed in inflate_fast()
- * - Make op and len in inflate_fast() unsigned for consistency
- * - Add FAR to lcode and dcode declarations in inflate_fast()
- * - Simplified bad distance check in inflate_fast()
- * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
- * source file infback.c to provide a call-back interface to inflate for
- * programs like gzip and unzip -- uses window as output buffer to avoid
- * window copying
- *
- * 1.2.beta5 1 Jan 2003
- * - Improved inflateBack() interface to allow the caller to provide initial
- * input in strm.
- * - Fixed stored blocks bug in inflateBack()
- *
- * 1.2.beta6 4 Jan 2003
- * - Added comments in inffast.c on effectiveness of POSTINC
- * - Typecasting all around to reduce compiler warnings
- * - Changed loops from while (1) or do {} while (1) to for (;;), again to
- * make compilers happy
- * - Changed type of window in inflateBackInit() to unsigned char *
- *
- * 1.2.beta7 27 Jan 2003
- * - Changed many types to unsigned or unsigned short to avoid warnings
- * - Added inflateCopy() function
- *
- * 1.2.0 9 Mar 2003
- * - Changed inflateBack() interface to provide separate opaque descriptors
- * for the in() and out() functions
- * - Changed inflateBack() argument and in_func typedef to swap the length
- * and buffer address return values for the input function
- * - Check next_in and next_out for Z_NULL on entry to inflate()
- *
- * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
- */
- #include "zutil.h"
- #include "inftrees.h"
- #include "inflate.h"
- #include "inffast.h"
- /* function prototypes */
- static void fixedtables(struct inflate_state *state);
- static int updatewindow(z_streamp strm, DWORD out);
- static DWORD syncsearch(DWORD *have, BYTE *buf, DWORD len);
- int ZEXPORT inflateReset(z_streamp strm)
- {
- struct inflate_state *state;
- if (strm == Z_NULL || strm->state == Z_NULL)
- {
- return Z_STREAM_ERROR;
- }
- state = (struct inflate_state*)strm->state;
- strm->total_in = strm->total_out = state->total = 0;
- strm->msg = Z_NULL;
- state->mode = HEAD;
- state->last = 0;
- state->havedict = 0;
- state->wsize = 0;
- state->whave = 0;
- state->hold = 0;
- state->bits = 0;
- state->lencode = state->distcode = state->next = state->codes;
- return Z_OK;
- }
- //-------------------------------------------------------------------------
- int ZEXPORT inflateInit2_(z_streamp strm, int windowBits, const BYTE *version, int stream_size)
- {
- struct inflate_state *state;
- if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || stream_size != (int)(sizeof(z_stream)))
- {
- return Z_VERSION_ERROR;
- } if (strm == Z_NULL)
- {
- return Z_STREAM_ERROR;
- }
- strm->msg = Z_NULL; /* in case we return an error */
- if (strm->zalloc == (alloc_func)0)
- {
- strm->zalloc = zcalloc;
- strm->opaque = (void*)0;
- }
- if (strm->zfree == (free_func)0)
- {
- strm->zfree = zcfree;
- }
- state = (struct inflate_state FAR*)ZALLOC(strm, 1, sizeof(struct inflate_state));
- if (state == Z_NULL)
- {
- return Z_MEM_ERROR;
- }
- strm->state = (void*)state;
- if (windowBits < 0)
- {
- state->wrap = 0;
- windowBits = - windowBits;
- }
- else
- {
- state->wrap = (windowBits >> 4) + 1;
- #ifdef GUNZIP
- if (windowBits < 48)
- {
- windowBits &= 15;
- }
- #endif
- }
- if (windowBits < 8 || windowBits > 15)
- {
- ZFREE(strm, state);
- strm->state = Z_NULL;
- return Z_STREAM_ERROR;
- }
- state->wbits = (DWORD)windowBits;
- state->window = Z_NULL;
- return inflateReset(strm);
- }
- //-------------------------------------------------------------------------
- int ZEXPORT inflateInit_(z_streamp strm, const BYTE *version, int stream_size)
- {
- return inflateInit2_(strm, DEF_WBITS, version, stream_size);
- }
- /*
- Return state with length and distance decoding tables and index sizes set to
- fixed code decoding. Normally this returns fixed tables from inffixed.h.
- If BUILDFIXED is defined, then instead this routine builds the tables the
- first time it's called, and returns those tables the first time and
- thereafter. This reduces the size of the code by about 2K bytes, in
- exchange for a little execution time. However, BUILDFIXED should not be
- used for threaded applications, since the rewriting of the tables and virgin
- may not be thread-safe.
- */
- static void fixedtables(struct inflate_state *state)
- {
- static DWORD init = 0;
- static code *next;
- static code *lenfix;
- static code *distfix;
- static code fixed[544];
- /* build fixed huffman tables if first call (may not be thread safe) */
- if (!init)
- {
- DWORD sym = 0;
- DWORD bits;
- init++;
- /* literal/length table */
- while (sym < 144)
- {
- state->lens[sym++] = 8;
- }
- while (sym < 256)
- {
- state->lens[sym++] = 9;
- }
- while (sym < 280)
- {
- state->lens[sym++] = 7;
- }
- while (sym < 288)
- {
- state->lens[sym++] = 8;
- }
- next = fixed;
- lenfix = next;
- bits = 9;
- inflate_table(LENS, state->lens, 288, &next, &bits, state->work);
- /* distance table */
- for (sym = 0; sym < 32;)
- {
- state->lens[sym++] = 5;
- }
- distfix = next;
- bits = 5;
- inflate_table(DISTS, state->lens, 32, &next, &bits, state->work);
- }
- state->lencode = lenfix;
- state->lenbits = 9;
- state->distcode = distfix;
- state->distbits = 5;
- }
- /*
- Update the window with the last wsize (normally 32K) bytes written before
- returning. If window does not exist yet, create it. This is only called
- when a window is already in use, or when output has been written during this
- inflate call, but the end of the deflate stream has not been reached yet.
- It is also called to create a window for dictionary data when a dictionary
- is loaded.
- Providing output buffers larger than 32K to inflate() should provide a speed
- advantage, since only the last 32K of output is copied to the sliding window
- upon return from inflate(), and since all distances after the first 32K of
- output will fall in the output data, making match copies simpler and faster.
- The advantage may be dependent on the size of the processor's data caches.
- */
- static int updatewindow(z_streamp strm, DWORD out)
- {
- struct inflate_state *state;
- DWORD copy, dist;
- state = (struct inflate_state FAR*)strm->state;
- /* if it hasn't been done already, allocate space for the window */
- if (state->window == Z_NULL)
- {
- state->window = (BYTE FAR*)ZALLOC(strm, 1U << state->wbits, sizeof(BYTE));
- if (state->window == Z_NULL)
- {
- return 1;
- }
- }
- /* if window not in use yet, initialize */
- if (state->wsize == 0)
- {
- state->wsize = 1U << state->wbits;
- state->write = 0;
- state->whave = 0;
- }
- /* copy state->wsize or less output bytes into the circular window */
- copy = out - strm->avail_out;
- if (copy >= state->wsize)
- {
- zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
- state->write = 0;
- state->whave = state->wsize;
- }
- else
- {
- dist = state->wsize - state->write;
- if (dist > copy)
- {
- dist = copy;
- }
- zmemcpy(state->window + state->write, strm->next_out - copy, dist);
- copy -= dist;
- if (copy)
- {
- zmemcpy(state->window, strm->next_out - copy, copy);
- state->write = copy;
- state->whave = state->wsize;
- }
- else
- {
- state->write += dist;
- if (state->write == state->wsize)
- {
- state->write = 0;
- }
- if (state->whave < state->wsize)
- {
- state->whave += dist;
- }
- }
- }
- return 0;
- }
- /* Macros for inflate(): */
- /* check function to use adler32() for zlib or crc32() for gzip */
- #ifdef GUNZIP
- #define UPDATE(check, buf, len)
- (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
- #else
- #define UPDATE(check, buf, len) adler32(check, buf, len)
- #endif
- /* check macros for header crc */
- #ifdef GUNZIP
- #define CRC2(check, word)
- {
- hbuf[0] = (BYTE)(word);
- hbuf[1] = (BYTE)((word) >> 8);
- check = crc32(check, hbuf, 2);
- }
- #define CRC4(check, word)
- {
- hbuf[0] = (BYTE)(word);
- hbuf[1] = (BYTE)((word) >> 8);
- hbuf[2] = (BYTE)((word) >> 16);
- hbuf[3] = (BYTE)((word) >> 24);
- check = crc32(check, hbuf, 4);
- }
- #endif
- /* Load registers with state in inflate() for speed */
- #define LOAD()
- {
- put = strm->next_out;
- left = strm->avail_out;
- next = strm->next_in;
- have = strm->avail_in;
- hold = state->hold;
- bits = state->bits;
- }
- /* Restore state from registers in inflate() */
- #define RESTORE()
- {
- strm->next_out = put;
- strm->avail_out = left;
- strm->next_in = next;
- strm->avail_in = have;
- state->hold = hold;
- state->bits = bits;
- }
- /* Clear the input bit accumulator */
- #define INITBITS() { hold = 0; bits = 0; }
- /* Get a byte of input into the bit accumulator, or return from inflate()
- if there is no input available. */
- #define PULLBYTE() { if (have == 0) goto inf_leave; have--; hold += (DWORD)(*next++) << bits; bits += 8; }
- /* Assure that there are at least n bits in the bit accumulator. If there is
- not enough available input to do that, then return from inflate(). */
- #define NEEDBITS(n) { while (bits < (DWORD)(n)) { PULLBYTE(); } }
- /* Return the low n bits of the bit accumulator (n < 16) */
- #define BITS(n) ((DWORD)hold & ((1U << (n)) - 1))
- /* Remove n bits from the bit accumulator */
- #define DROPBITS(n) { hold >>= (n); bits -= (DWORD)(n); }
- /* Remove zero to seven bits as needed to go to a byte boundary */
- #define BYTEBITS() { hold >>= bits & 7; bits -= bits & 7; }
- /* Reverse the bytes in a 32-bit value */
- #define REVERSE(q) (q >> 24 | q << 24 | ((q << 8) & 0x00FF0000) | ((q >> 8) & 0x0000FF00))
- //((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) +
- //(((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
- /*
- inflate() uses a state machine to process as much input data and generate as
- much output data as possible before returning. The state machine is
- structured roughly as follows:
- for (;;) switch (state) {
- ...
- case STATEn:
- if (not enough input data or output space to make progress)
- return;
- ... make progress ...
- state = STATEm;
- break;
- ...
- }
- so when inflate() is called again, the same case is attempted again, and
- if the appropriate resources are provided, the machine proceeds to the
- next state. The NEEDBITS() macro is usually the way the state evaluates
- whether it can proceed or should return. NEEDBITS() does the return if
- the requested bits are not available. The typical use of the BITS macros
- is:
- NEEDBITS(n);
- ... do something with BITS(n) ...
- DROPBITS(n);
- where NEEDBITS(n) either returns from inflate() if there isn't enough
- input left to load n bits into the accumulator, or it continues. BITS(n)
- gives the low n bits in the accumulator. When done, DROPBITS(n) drops
- the low n bits off the accumulator. INITBITS() clears the accumulator
- and sets the number of available bits to zero. BYTEBITS() discards just
- enough bits to put the accumulator on a byte boundary. After BYTEBITS()
- and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
- NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
- if there is no input available. The decoding of variable length codes uses
- PULLBYTE() directly in order to pull just enough bytes to decode the next
- code, and no more.
- Some states loop until they get enough input, making sure that enough
- state information is maintained to continue the loop where it left off
- if NEEDBITS() returns in the loop. For example, want, need, and keep
- would all have to actually be part of the saved state in case NEEDBITS()
- returns:
- case STATEw:
- while (want < need) {
- NEEDBITS(n);
- keep[want++] = BITS(n);
- DROPBITS(n);
- }
- state = STATEx;
- case STATEx:
- As shown above, if the next state is also the next case, then the break
- is omitted.
- A state may also return if there is not enough output space available to
- complete that state. Those states are copying stored data, writing a
- literal byte, and copying a matching string.
- When returning, a "goto inf_leave" is used to update the total counters,
- update the check value, and determine whether any progress has been made
- during that inflate() call in order to return the proper return code.
- Progress is defined as a change in either strm->avail_in or strm->avail_out.
- When there is a window, goto inf_leave will update the window with the last
- output written. If a goto inf_leave occurs in the middle of decompression
- and there is no window currently, goto inf_leave will create one and copy
- output to the window for the next call of inflate().
- In this implementation, the flush parameter of inflate() only affects the
- return code (per zlib.h). inflate() always writes as much as possible to
- strm->next_out, given the space available and the provided input--the effect
- documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
- the allocation of and copying into a sliding window until necessary, which
- provides the effect documented in zlib.h for Z_FINISH when the entire input
- stream available. So the only thing the flush parameter actually does is:
- when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
- will return Z_BUF_ERROR if it has not reached the end of the stream.
- */
- int ZEXPORT inflate(z_streamp strm, int flush)
- {
- struct inflate_state *state;
- BYTE *next; /* next input */
- BYTE *put; /* next output */
- DWORD have, left; /* available input and output */
- DWORD hold; /* bit buffer */
- DWORD bits; /* bits in bit buffer */
- DWORD in, out; /* save starting available input and output */
- DWORD copy; /* number of stored or match bytes to copy */
- BYTE *from; /* where to copy match bytes from */
- code this; /* current decoding table entry */
- code last; /* parent table entry */
- DWORD len; /* length to copy for repeats, bits to drop */
- int ret; /* return code */
- #ifdef GUNZIP
- BYTE hbuf[4]; /* buffer for gzip header crc calculation */
- #endif
- static const WORD order[19] = /* permutation of code lengths */
- {
- 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
- };
- if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL || (strm->next_in == Z_NULL && strm->avail_in != 0))
- {
- return Z_STREAM_ERROR;
- }
- state = (struct inflate_state FAR*)strm->state;
- if (state->mode == TYPE)
- {
- state->mode = TYPEDO;
- }
- /* skip check */
- LOAD();
- in = have;
- out = left;
- ret = Z_OK;
- for (;;)
- switch (state->mode)
- {
- case HEAD:
- if (state->wrap == 0)
- {
- state->mode = TYPEDO;
- break;
- }
- NEEDBITS(16);
- #ifdef GUNZIP
- if ((state->wrap &2) && hold == 0x8b1f)
- {
- /* gzip header */
- state->check = crc32(0L, Z_NULL, 0);
- CRC2(state->check, hold);
- INITBITS();
- state->mode = FLAGS;
- break;
- }
- state->flags = 0; /* expect zlib header */
- if (!(state->wrap &1) || /* check if zlib header allowed */
- #else
- if (
- #endif
- ((BITS(8) << 8) + (hold >> 8)) % 31)
- {
- state->mode = BAD; break;
- }
- if (BITS(4) != Z_DEFLATED)
- {
- state->mode = BAD; break;
- }
- DROPBITS(4); if (BITS(4) + 8 > state->wbits)
- {
- state->mode = BAD; break;
- }
- strm->adler = state->check = adler32(0L, Z_NULL, 0); state->mode = hold &0x200 ? DICTID : TYPE; INITBITS(); break;
- #ifdef GUNZIP
- case FLAGS:
- NEEDBITS(16); state->flags = (int)(hold); if ((state->flags &0xff) != Z_DEFLATED)
- {
- state->mode = BAD; break;
- }
- if (state->flags &0xe000)
- {
- state->mode = BAD; break;
- }
- if (state->flags &0x0200)CRC2(state->check, hold); INITBITS(); state->mode = TIME; case TIME:
- NEEDBITS(32); if (state->flags &0x0200)CRC4(state->check, hold); INITBITS(); state->mode = OS; case OS:
- NEEDBITS(16); if (state->flags &0x0200)CRC2(state->check, hold); INITBITS(); state->mode = EXLEN; case EXLEN:
- if (state->flags &0x0400)
- {
- NEEDBITS(16); state->length = (DWORD)(hold); if (state->flags &0x0200)CRC2(state->check, hold); INITBITS();
- }
- state->mode = EXTRA; case EXTRA:
- if (state->flags &0x0400)
- {
- copy = state->length; if (copy > have)copy = have; if (copy)
- {
- if (state->flags &0x0200)state->check = crc32(state->check, next, copy); have -= copy; next += copy; state->length -= copy;
- }
- if (state->length)goto inf_leave;
- }
- state->mode = NAME; case NAME:
- if (state->flags &0x0800)
- {
- if (have == 0)goto inf_leave; copy = 0;
- do
- {
- len = (DWORD)(next[copy++]);
- }
- while (len && copy < have); if (state->flags &0x02000)state->check = crc32(state->check, next, copy); have -= copy; next += copy; if (len)goto inf_leave;
- }
- state->mode = COMMENT; case COMMENT:
- if (state->flags &0x1000)
- {
- if (have == 0)goto inf_leave; copy = 0;
- do
- {
- len = (DWORD)(next[copy++]);
- }
- while (len && copy < have); if (state->flags &0x02000)state->check = crc32(state->check, next, copy); have -= copy; next += copy; if (len)goto inf_leave;
- }
- state->mode = HCRC; case HCRC:
- if (state->flags &0x0200)
- {
- NEEDBITS(16); if (hold != (state->check &0xffff))
- {
- state->mode = BAD; break;
- }
- INITBITS();
- }
- strm->adler = state->check = crc32(0L, Z_NULL, 0); state->mode = TYPE; break;
- #endif
- case DICTID:
- NEEDBITS(32); strm->adler = state->check = REVERSE(hold); INITBITS(); state->mode = DICT; case DICT:
- if (state->havedict == 0)
- {
- RESTORE(); return Z_NEED_DICT;
- }
- strm->adler = state->check = adler32(0L, Z_NULL, 0); state->mode = TYPE; case TYPE:
- if (flush == Z_BLOCK)goto inf_leave; case TYPEDO:
- if (state->last)
- {
- BYTEBITS(); state->mode = CHECK; break;
- }
- NEEDBITS(3); state->last = BITS(1); DROPBITS(1); switch (BITS(2))
- {
- case 0:
- /* stored block */
- state->mode = STORED; break;
- case 1:
- /* fixed block */
- fixedtables(state);
- state->mode = LEN; /* decode codes */
- break; case 2:
- /* dynamic block */
- state->mode = TABLE; break; case 3:
- state->mode = BAD;
- }
- DROPBITS(2); break; case STORED:
- BYTEBITS(); /* go to byte boundary */
- NEEDBITS(32); if ((hold &0xffff) != ((hold >> 16) ^ 0xffff))
- {
- state->mode = BAD; break;
- }
- state->length = (DWORD)hold &0xffff; INITBITS(); state->mode = COPY; case COPY:
- copy = state->length; if (copy)
- {
- if (copy > have)copy = have; if (copy > left)copy = left; if (copy == 0)goto inf_leave; zmemcpy(put, next, copy); have -= copy; next += copy; left -= copy; put += copy; state->length -= copy; break;
- }
- state->mode = TYPE; break; case TABLE:
- NEEDBITS(14); state->nlen = BITS(5) + 257; DROPBITS(5); state->ndist = BITS(5) + 1; DROPBITS(5); state->ncode = BITS(4) + 4; DROPBITS(4);
- #ifndef PKZIP_BUG_WORKAROUND
- if (state->nlen > 286 || state->ndist > 30)
- {
- state->mode = BAD; break;
- }
- #endif
- state->have = 0; state->mode = LENLENS; case LENLENS:
- while (state->have < state->ncode)
- {
- NEEDBITS(3); state->lens[order[state->have++]] = (WORD)BITS(3); DROPBITS(3);
- }
- while (state->have < 19)state->lens[order[state->have++]] = 0; state->next = state->codes; state->lencode = (code const FAR*)(state->next); state->lenbits = 7; ret = inflate_table(CODES, state->lens, 19, &(state->next), &(state->lenbits), state->work); if (ret)
- {
- state->mode = BAD; break;
- }
- state->have = 0; state->mode = CODELENS; case CODELENS:
- while (state->have < state->nlen + state->ndist)
- {
- for (;;)
- {
- this = state->lencode[BITS(state->lenbits)]; if ((DWORD)(this.bits) <= bits)break; PULLBYTE();
- }
- if (this.val < 16)
- {
- NEEDBITS(this.bits); DROPBITS(this.bits); state->lens[state->have++] = this.val;
- }
- else
- {
- if (this.val == 16)
- {
- NEEDBITS(this.bits + 2); DROPBITS(this.bits); if (state->have == 0)
- {
- state->mode = BAD; break;
- }
- len = state->lens[state->have - 1]; copy = 3+BITS(2); DROPBITS(2);
- }
- else if (this.val == 17)
- {
- NEEDBITS(this.bits + 3); DROPBITS(this.bits); len = 0; copy = 3+BITS(3); DROPBITS(3);
- }
- else
- {
- NEEDBITS(this.bits + 7); DROPBITS(this.bits); len = 0; copy = 11+BITS(7); DROPBITS(7);
- }
- if (state->have + copy > state->nlen + state->ndist)
- {
- state->mode = BAD; break;
- }
- while (copy--)state->lens[state->have++] = (WORD)len;
- }
- }
- /* build code tables */
- state->next = state->codes; state->lencode = (code const*)(state->next); state->lenbits = 9; ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), &(state->lenbits), state->work); if (ret)
- {
- state->mode = BAD; break;
- }
- state->distcode = (code const FAR*)(state->next); state->distbits = 6; ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, &(state->next), &(state->distbits), state->work); if (ret)
- {
- state->mode = BAD; break;
- }
- state->mode = LEN; case LEN:
- if (have >= 6 && left >= 258)
- {
- RESTORE(); inflate_fast(strm, out); LOAD(); break;
- }
- for (;;)
- {
- this = state->lencode[BITS(state->lenbits)]; if ((DWORD)(this.bits) <= bits)break; PULLBYTE();
- }
- if (this.op && (this.op &0xf0) == 0)
- {
- last = this; for (;;)
- {
- this = state->lencode[last.val + (BITS(last.bits + last.op) >> last.bits)]; if ((DWORD)(last.bits + this.bits) <= bits)break; PULLBYTE();
- }
- DROPBITS(last.bits);
- }
- DROPBITS(this.bits); state->length = (DWORD)this.val; if ((int)(this.op) == 0)
- {
- state->mode = LIT; break;
- }
- if (this.op &32)
- {
- state->mode = TYPE; break;
- }
- if (this.op &64)
- {
- state->mode = BAD; break;
- }
- state->extra = (DWORD)(this.op) &15; state->mode = LENEXT; case LENEXT:
- if (state->extra)
- {
- NEEDBITS(state->extra); state->length += BITS(state->extra); DROPBITS(state->extra);
- }
- state->mode = DIST; case DIST:
- for (;;)
- {
- this = state->distcode[BITS(state->distbits)]; if ((DWORD)(this.bits) <= bits)break; PULLBYTE();
- }
- if ((this.op &0xf0) == 0)
- {
- last = this; for (;;)
- {
- this = state->distcode[last.val + (BITS(last.bits + last.op) >> last.bits)]; if ((DWORD)(last.bits + this.bits) <= bits)break; PULLBYTE();
- }
- DROPBITS(last.bits);
- }
- DROPBITS(this.bits); if (this.op &64)
- {
- state->mode = BAD; break;
- }
- state->offset = (DWORD)this.val; state->extra = (DWORD)(this.op) &15; state->mode = DISTEXT; case DISTEXT:
- if (state->extra)
- {
- NEEDBITS(state->extra); state->offset += BITS(state->extra); DROPBITS(state->extra);
- }
- if (state->offset > state->whave + out - left)
- {
- state->mode = BAD; break;
- }
- state->mode = MATCH; case MATCH:
- if (left == 0)goto inf_leave; copy = out - left; if (state->offset > copy)
- {
- /* copy from window */
- copy = state->offset - copy; if (copy > state->write)
- {
- copy -= state->write; from = state->window + (state->wsize - copy);
- }
- else
- from = state->window + (state->write - copy); if (copy > state->length)copy = state->length;
- }
- else
- {
- /* copy from output */
- from = put - state->offset; copy = state->length;
- }
- if (copy > left)copy = left; left -= copy; state->length -= copy;
- do
- {
- *put++ = *from++;
- }
- while (--copy); if (state->length == 0)state->mode = LEN; break; case LIT:
- if (left == 0)goto inf_leave; *put++ = (BYTE)(state->length); left--; state->mode = LEN; break; case CHECK:
- if (state->wrap)
- {
- NEEDBITS(32); out -= left; strm->total_out += out; state->total += out; if (out)strm->adler = state->check = UPDATE(state->check, put - out, out); out = left; if ((
- #ifdef GUNZIP
- state->flags ? hold :
- #endif
- REVERSE(hold)) != state->check)
- {
- state->mode = BAD; break;
- }
- INITBITS();
- }
- #ifdef GUNZIP
- state->mode = LENGTH; case LENGTH:
- if (state->wrap && state->flags)
- {
- NEEDBITS(32); if (hold != (state->total &0xffffffffUL))
- {
- state->mode = BAD; break;
- }
- INITBITS();
- }
- #endif
- state->mode = DONE; case DONE:
- ret = Z_STREAM_END; goto inf_leave; case BAD:
- ret = Z_DATA_ERROR; goto inf_leave; case MEM:
- return Z_MEM_ERROR; case SYNC:
- default: return Z_STREAM_ERROR;
- }
- /*
- Return from inflate(), updating the total counts and the check value.
- If there was no progress during the inflate() call, return a buffer
- error. Call updatewindow() to create and/or update the window state.
- Note: a memory error from inflate() is non-recoverable.
- */
- inf_leave: RESTORE(); if (state->wsize || (state->mode < CHECK && out != strm->avail_out))if (updatewindow(strm, out))
- {
- state->mode = MEM; return Z_MEM_ERROR;
- } in -= strm->avail_in; out -= strm->avail_out; strm->total_in += in; strm->total_out += out; state->total += out; if (state->wrap && out)strm->adler = state->check = UPDATE(state->check, strm->next_out - out, out); strm->data_type = state->bits + (state->last ? 64 : 0) + (state->mode == TYPE ? 128 : 0); if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)ret = Z_BUF_ERROR; return ret;
- }
- //-------------------------------------------------------------------------
- int ZEXPORT inflateEnd(z_streamp strm)
- {
- struct inflate_state *state;
- if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
- {
- return Z_STREAM_ERROR;
- }
- state = (struct inflate_state FAR*)strm->state;
- if (state->window != Z_NULL)
- {
- ZFREE(strm, state->window);
- }
- ZFREE(strm, strm->state);
- strm->state = Z_NULL;
- return Z_OK;
- }
- //-------------------------------------------------------------------------
- int ZEXPORT inflateSetDictionary(z_streamp strm, const Bytef *dictionary, DWORD dictLength)
- {
- struct inflate_state *state; DWORD id;
- /* check state */
- if (strm == Z_NULL || strm->state == Z_NULL)
- {
- return Z_STREAM_ERROR;
- }
- state = (struct inflate_state FAR*)strm->state;
- if (state->mode != DICT)
- {
- return Z_STREAM_ERROR;
- }
- /* check for correct dictionary id */
- id = adler32(0L, Z_NULL, 0); id = adler32(id, dictionary, dictLength);
- if (id != state->check)
- {
- return Z_DATA_ERROR;
- }
- /* copy dictionary to window */
- if (updatewindow(strm, strm->avail_out))
- {
- state->mode = MEM; return Z_MEM_ERROR;
- }
- if (dictLength > state->wsize)
- {
- zmemcpy(state->window, dictionary + dictLength - state->wsize, state->wsize); state->whave = state->wsize;
- }
- else
- {
- zmemcpy(state->window + state->wsize - dictLength, dictionary, dictLength); state->whave = dictLength;
- }
- state->havedict = 1; return Z_OK;
- }
- /*
- Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
- or when out of input. When called, *have is the number of pattern bytes
- found in order so far, in 0..3. On return *have is updated to the new
- state. If on return *have equals four, then the pattern was found and the
- return value is how many bytes were read including the last byte of the
- pattern. If *have is less than four, then the pattern has not been found
- yet and the return value is len. In the latter case, syncsearch() can be
- called again with more data and the *have state. *have is initialized to
- zero for the first call.
- */
- static DWORD syncsearch(DWORD *have, BYTE *buf, DWORD len)
- {
- DWORD got; DWORD next;
- got = *have; next = 0;
- while (next < len && got < 4)
- {
- if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))got++;
- else if (buf[next])got = 0;
- else
- got = 4-got; next++;
- }
- *have = got; return next;
- }
- //-------------------------------------------------------------------------
- int ZEXPORT inflateSync(z_streamp strm)
- {
- DWORD len; /* number of bytes to look at or looked at */
- DWORD in, out; /* temporary to save total_in and total_out */
- BYTE buf[4]; /* to restore bit buffer to byte string */
- struct inflate_state *state;
- /* check parameters */
- if (strm == Z_NULL || strm->state == Z_NULL)return Z_STREAM_ERROR; state = (struct inflate_state FAR*)strm->state; if (strm->avail_in == 0 && state->bits < 8)return Z_BUF_ERROR;
- /* if first time, start search in bit buffer */
- if (state->mode != SYNC)
- {
- state->mode = SYNC; state->hold <<= state->bits &7; state->bits -= state->bits &7; len = 0;
- while (state->bits >= 8)
- {
- buf[len++] = (BYTE)(state->hold); state->hold >>= 8; state->bits -= 8;
- } state->have = 0; syncsearch(&(state->have), buf, len);
- }
- /* search available input */
- len = syncsearch(&(state->have), strm->next_in, strm->avail_in); strm->avail_in -= len; strm->next_in += len; strm->total_in += len;
- /* return no joy or set up to restart inflate() on a new block */
- if (state->have != 4)return Z_DATA_ERROR; in = strm->total_in; out = strm->total_out; inflateReset(strm); strm->total_in = in; strm->total_out = out; state->mode = TYPE; return Z_OK;
- }
- /*
- Returns true if inflate is currently at the end of a block generated by
- Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
- implementation to provide an additional safety check. PPP uses
- Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
- block. When decompressing, PPP checks that at the end of input packet,
- inflate is waiting for these length bytes.
- */
- int ZEXPORT inflateSyncPoint(z_streamp strm)
- {
- struct inflate_state *state;
- if (strm == Z_NULL || strm->state == Z_NULL)
- {
- return Z_STREAM_ERROR;
- }
- state = (struct inflate_state FAR*)strm->state;
- return state->mode == STORED && state->bits == 0;
- }
- //-------------------------------------------------------------------------
- int ZEXPORT inflateCopy(z_streamp dest, z_streamp source)
- {
- struct inflate_state *state; struct inflate_state *copy; BYTE *window;
- /* check input */
- if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL || source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
- {
- return Z_STREAM_ERROR;
- }
- state = (struct inflate_state FAR*)source->state;
- /* allocate space */
- copy = (struct inflate_state FAR*)ZALLOC(source, 1, sizeof(struct inflate_state));
- if (copy == Z_NULL)
- {
- return Z_MEM_ERROR;
- }
- window = Z_NULL;
- if (state->window != Z_NULL)
- {
- window = (BYTE FAR*)ZALLOC(source, 1U << state->wbits, sizeof(BYTE));
- if (window == Z_NULL)
- {
- ZFREE(source, copy); return Z_MEM_ERROR;
- }
- }
- /* copy state */
- *dest = *source; *copy = *state;
- copy->lencode = copy->codes + (state->lencode - state->codes); copy->distcode = copy->codes + (state->distcode - state->codes); copy->next = copy->codes + (state->next - state->codes);
- if (window != Z_NULL)
- {
- zmemcpy(window, state->window, 1U << state->wbits);
- }
- copy->window = window; dest->state = (void*)copy; return Z_OK;
- }