1562 lines
54 KiB
C
1562 lines
54 KiB
C
/* inflate.c -- zlib decompression
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* Copyright (C) 1995-2016 Mark Adler
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* For conditions of distribution and use, see copyright notice in zlib.h
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*/
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/*
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* Change history:
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*
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* 1.2.beta0 24 Nov 2002
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* - First version -- complete rewrite of inflate to simplify code, avoid
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* creation of window when not needed, minimize use of window when it is
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* needed, make inffast.c even faster, implement gzip decoding, and to
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* improve code readability and style over the previous zlib inflate code
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*
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* 1.2.beta1 25 Nov 2002
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* - Use pointers for available input and output checking in inffast.c
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* - Remove input and output counters in inffast.c
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* - Change inffast.c entry and loop from avail_in >= 7 to >= 6
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* - Remove unnecessary second byte pull from length extra in inffast.c
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* - Unroll direct copy to three copies per loop in inffast.c
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*
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* 1.2.beta2 4 Dec 2002
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* - Change external routine names to reduce potential conflicts
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* - Correct filename to inffixed.h for fixed tables in inflate.c
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* - Make hbuf[] unsigned char to match parameter type in inflate.c
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* - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
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* to avoid negation problem on Alphas (64 bit) in inflate.c
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*
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* 1.2.beta3 22 Dec 2002
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* - Add comments on state->bits assertion in inffast.c
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* - Add comments on op field in inftrees.h
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* - Fix bug in reuse of allocated window after inflateReset()
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* - Remove bit fields--back to byte structure for speed
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* - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
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* - Change post-increments to pre-increments in inflate_fast(), PPC biased?
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* - Add compile time option, POSTINC, to use post-increments instead (Intel?)
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* - Make MATCH copy in inflate() much faster for when inflate_fast() not used
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* - Use local copies of stream next and avail values, as well as local bit
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* buffer and bit count in inflate()--for speed when inflate_fast() not used
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*
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* 1.2.beta4 1 Jan 2003
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* - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
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* - Move a comment on output buffer sizes from inffast.c to inflate.c
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* - Add comments in inffast.c to introduce the inflate_fast() routine
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* - Rearrange window copies in inflate_fast() for speed and simplification
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* - Unroll last copy for window match in inflate_fast()
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* - Use local copies of window variables in inflate_fast() for speed
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* - Pull out common wnext == 0 case for speed in inflate_fast()
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* - Make op and len in inflate_fast() unsigned for consistency
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* - Add FAR to lcode and dcode declarations in inflate_fast()
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* - Simplified bad distance check in inflate_fast()
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* - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
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* source file infback.c to provide a call-back interface to inflate for
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* programs like gzip and unzip -- uses window as output buffer to avoid
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* window copying
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*
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* 1.2.beta5 1 Jan 2003
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* - Improved inflateBack() interface to allow the caller to provide initial
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* input in strm.
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* - Fixed stored blocks bug in inflateBack()
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*
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* 1.2.beta6 4 Jan 2003
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* - Added comments in inffast.c on effectiveness of POSTINC
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* - Typecasting all around to reduce compiler warnings
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* - Changed loops from while (1) or do {} while (1) to for (;;), again to
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* make compilers happy
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* - Changed type of window in inflateBackInit() to unsigned char *
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*
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* 1.2.beta7 27 Jan 2003
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* - Changed many types to unsigned or unsigned short to avoid warnings
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* - Added inflateCopy() function
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*
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* 1.2.0 9 Mar 2003
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* - Changed inflateBack() interface to provide separate opaque descriptors
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* for the in() and out() functions
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* - Changed inflateBack() argument and in_func typedef to swap the length
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* and buffer address return values for the input function
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* - Check next_in and next_out for Z_NULL on entry to inflate()
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*
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* The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
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*/
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#include "zutil.h"
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#include "inftrees.h"
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#include "inflate.h"
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#include "inffast.h"
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#ifdef MAKEFIXED
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# ifndef BUILDFIXED
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# define BUILDFIXED
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# endif
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#endif
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/* function prototypes */
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local int inflateStateCheck OF((z_streamp strm));
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local void fixedtables OF((struct inflate_state FAR *state));
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local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
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unsigned copy));
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#ifdef BUILDFIXED
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void makefixed OF((void));
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#endif
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local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
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unsigned len));
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local int inflateStateCheck(strm)
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z_streamp strm;
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{
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struct inflate_state FAR *state;
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if (strm == Z_NULL ||
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strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
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return 1;
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state = (struct inflate_state FAR *)strm->state;
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if (state == Z_NULL || state->strm != strm ||
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state->mode < HEAD || state->mode > SYNC)
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return 1;
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return 0;
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}
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int ZEXPORT inflateResetKeep(strm)
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z_streamp strm;
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{
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struct inflate_state FAR *state;
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if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
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state = (struct inflate_state FAR *)strm->state;
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strm->total_in = strm->total_out = state->total = 0;
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strm->msg = Z_NULL;
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if (state->wrap) /* to support ill-conceived Java test suite */
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strm->adler = state->wrap & 1;
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state->mode = HEAD;
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state->last = 0;
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state->havedict = 0;
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state->dmax = 32768U;
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state->head = Z_NULL;
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state->hold = 0;
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state->bits = 0;
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state->lencode = state->distcode = state->next = state->codes;
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state->sane = 1;
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state->back = -1;
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Tracev((stderr, "inflate: reset\n"));
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return Z_OK;
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}
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int ZEXPORT inflateReset(strm)
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z_streamp strm;
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{
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struct inflate_state FAR *state;
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if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
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state = (struct inflate_state FAR *)strm->state;
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state->wsize = 0;
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state->whave = 0;
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state->wnext = 0;
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return inflateResetKeep(strm);
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}
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int ZEXPORT inflateReset2(strm, windowBits)
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z_streamp strm;
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int windowBits;
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{
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int wrap;
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struct inflate_state FAR *state;
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/* get the state */
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if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
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state = (struct inflate_state FAR *)strm->state;
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/* extract wrap request from windowBits parameter */
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if (windowBits < 0) {
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wrap = 0;
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windowBits = -windowBits;
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}
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else {
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wrap = (windowBits >> 4) + 5;
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#ifdef GUNZIP
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if (windowBits < 48)
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windowBits &= 15;
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#endif
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}
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/* set number of window bits, free window if different */
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if (windowBits && (windowBits < 8 || windowBits > 15))
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return Z_STREAM_ERROR;
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if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
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ZFREE(strm, state->window);
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state->window = Z_NULL;
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}
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/* update state and reset the rest of it */
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state->wrap = wrap;
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state->wbits = (unsigned)windowBits;
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return inflateReset(strm);
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}
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int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
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z_streamp strm;
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int windowBits;
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const char *version;
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int stream_size;
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{
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int ret;
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struct inflate_state FAR *state;
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if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
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stream_size != (int)(sizeof(z_stream)))
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return Z_VERSION_ERROR;
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if (strm == Z_NULL) return Z_STREAM_ERROR;
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strm->msg = Z_NULL; /* in case we return an error */
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if (strm->zalloc == (alloc_func)0) {
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#ifdef Z_SOLO
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return Z_STREAM_ERROR;
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#else
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strm->zalloc = zcalloc;
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strm->opaque = (voidpf)0;
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#endif
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}
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if (strm->zfree == (free_func)0)
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#ifdef Z_SOLO
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return Z_STREAM_ERROR;
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#else
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strm->zfree = zcfree;
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#endif
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state = (struct inflate_state FAR *)
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ZALLOC(strm, 1, sizeof(struct inflate_state));
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if (state == Z_NULL) return Z_MEM_ERROR;
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Tracev((stderr, "inflate: allocated\n"));
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strm->state = (struct internal_state FAR *)state;
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state->strm = strm;
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state->window = Z_NULL;
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state->mode = HEAD; /* to pass state test in inflateReset2() */
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ret = inflateReset2(strm, windowBits);
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if (ret != Z_OK) {
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ZFREE(strm, state);
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strm->state = Z_NULL;
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}
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return ret;
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}
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int ZEXPORT inflateInit_(strm, version, stream_size)
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z_streamp strm;
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const char *version;
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int stream_size;
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{
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return inflateInit2_(strm, DEF_WBITS, version, stream_size);
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}
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int ZEXPORT inflatePrime(strm, bits, value)
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z_streamp strm;
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int bits;
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int value;
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{
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struct inflate_state FAR *state;
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if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
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state = (struct inflate_state FAR *)strm->state;
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if (bits < 0) {
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state->hold = 0;
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state->bits = 0;
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return Z_OK;
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}
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if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
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value &= (1L << bits) - 1;
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state->hold += (unsigned)value << state->bits;
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state->bits += (uInt)bits;
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return Z_OK;
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}
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/*
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Return state with length and distance decoding tables and index sizes set to
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fixed code decoding. Normally this returns fixed tables from inffixed.h.
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If BUILDFIXED is defined, then instead this routine builds the tables the
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first time it's called, and returns those tables the first time and
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thereafter. This reduces the size of the code by about 2K bytes, in
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exchange for a little execution time. However, BUILDFIXED should not be
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used for threaded applications, since the rewriting of the tables and virgin
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may not be thread-safe.
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*/
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local void fixedtables(state)
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struct inflate_state FAR *state;
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{
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#ifdef BUILDFIXED
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static int virgin = 1;
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static code *lenfix, *distfix;
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static code fixed[544];
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/* build fixed huffman tables if first call (may not be thread safe) */
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if (virgin) {
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unsigned sym, bits;
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static code *next;
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/* literal/length table */
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sym = 0;
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while (sym < 144) state->lens[sym++] = 8;
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while (sym < 256) state->lens[sym++] = 9;
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while (sym < 280) state->lens[sym++] = 7;
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while (sym < 288) state->lens[sym++] = 8;
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next = fixed;
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lenfix = next;
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bits = 9;
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inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
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/* distance table */
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sym = 0;
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while (sym < 32) state->lens[sym++] = 5;
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distfix = next;
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bits = 5;
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inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
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/* do this just once */
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virgin = 0;
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}
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#else /* !BUILDFIXED */
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# include "inffixed.h"
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#endif /* BUILDFIXED */
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state->lencode = lenfix;
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state->lenbits = 9;
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state->distcode = distfix;
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state->distbits = 5;
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}
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#ifdef MAKEFIXED
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#include <stdio.h>
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/*
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Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
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defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
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those tables to stdout, which would be piped to inffixed.h. A small program
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can simply call makefixed to do this:
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void makefixed(void);
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int main(void)
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{
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makefixed();
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return 0;
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}
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Then that can be linked with zlib built with MAKEFIXED defined and run:
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a.out > inffixed.h
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*/
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void makefixed()
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{
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unsigned low, size;
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struct inflate_state state;
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fixedtables(&state);
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puts(" /* inffixed.h -- table for decoding fixed codes");
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puts(" * Generated automatically by makefixed().");
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puts(" */");
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puts("");
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puts(" /* WARNING: this file should *not* be used by applications.");
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puts(" It is part of the implementation of this library and is");
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puts(" subject to change. Applications should only use zlib.h.");
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puts(" */");
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puts("");
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size = 1U << 9;
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printf(" static const code lenfix[%u] = {", size);
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low = 0;
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for (;;) {
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if ((low % 7) == 0) printf("\n ");
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printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
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state.lencode[low].bits, state.lencode[low].val);
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if (++low == size) break;
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putchar(',');
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}
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puts("\n };");
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size = 1U << 5;
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printf("\n static const code distfix[%u] = {", size);
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low = 0;
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for (;;) {
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if ((low % 6) == 0) printf("\n ");
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printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
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state.distcode[low].val);
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if (++low == size) break;
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putchar(',');
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}
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puts("\n };");
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}
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#endif /* MAKEFIXED */
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/*
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Update the window with the last wsize (normally 32K) bytes written before
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returning. If window does not exist yet, create it. This is only called
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when a window is already in use, or when output has been written during this
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inflate call, but the end of the deflate stream has not been reached yet.
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It is also called to create a window for dictionary data when a dictionary
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is loaded.
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Providing output buffers larger than 32K to inflate() should provide a speed
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advantage, since only the last 32K of output is copied to the sliding window
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upon return from inflate(), and since all distances after the first 32K of
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output will fall in the output data, making match copies simpler and faster.
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The advantage may be dependent on the size of the processor's data caches.
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*/
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local int updatewindow(strm, end, copy)
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z_streamp strm;
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const Bytef *end;
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unsigned copy;
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{
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struct inflate_state FAR *state;
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unsigned dist;
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state = (struct inflate_state FAR *)strm->state;
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/* if it hasn't been done already, allocate space for the window */
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if (state->window == Z_NULL) {
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state->window = (unsigned char FAR *)
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ZALLOC(strm, 1U << state->wbits,
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sizeof(unsigned char));
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if (state->window == Z_NULL) return 1;
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}
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/* if window not in use yet, initialize */
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if (state->wsize == 0) {
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state->wsize = 1U << state->wbits;
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state->wnext = 0;
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state->whave = 0;
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}
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/* copy state->wsize or less output bytes into the circular window */
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if (copy >= state->wsize) {
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zmemcpy(state->window, end - state->wsize, state->wsize);
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state->wnext = 0;
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state->whave = state->wsize;
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}
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else {
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dist = state->wsize - state->wnext;
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if (dist > copy) dist = copy;
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zmemcpy(state->window + state->wnext, end - copy, dist);
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copy -= dist;
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if (copy) {
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zmemcpy(state->window, end - copy, copy);
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state->wnext = copy;
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state->whave = state->wsize;
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}
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else {
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state->wnext += dist;
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if (state->wnext == state->wsize) state->wnext = 0;
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if (state->whave < state->wsize) state->whave += dist;
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}
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}
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return 0;
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}
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/* Macros for inflate(): */
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/* check function to use adler32() for zlib or crc32() for gzip */
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#ifdef GUNZIP
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# define UPDATE(check, buf, len) \
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(state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
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#else
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# define UPDATE(check, buf, len) adler32(check, buf, len)
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#endif
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/* check macros for header crc */
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#ifdef GUNZIP
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# define CRC2(check, word) \
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do { \
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hbuf[0] = (unsigned char)(word); \
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hbuf[1] = (unsigned char)((word) >> 8); \
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check = crc32(check, hbuf, 2); \
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} while (0)
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# define CRC4(check, word) \
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do { \
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hbuf[0] = (unsigned char)(word); \
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hbuf[1] = (unsigned char)((word) >> 8); \
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hbuf[2] = (unsigned char)((word) >> 16); \
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hbuf[3] = (unsigned char)((word) >> 24); \
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check = crc32(check, hbuf, 4); \
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} while (0)
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#endif
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/* Load registers with state in inflate() for speed */
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#define LOAD() \
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do { \
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put = strm->next_out; \
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left = strm->avail_out; \
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next = strm->next_in; \
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have = strm->avail_in; \
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hold = state->hold; \
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bits = state->bits; \
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} while (0)
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|
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/* Restore state from registers in inflate() */
|
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#define RESTORE() \
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do { \
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strm->next_out = put; \
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strm->avail_out = left; \
|
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strm->next_in = next; \
|
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strm->avail_in = have; \
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state->hold = hold; \
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state->bits = bits; \
|
|
} while (0)
|
|
|
|
/* Clear the input bit accumulator */
|
|
#define INITBITS() \
|
|
do { \
|
|
hold = 0; \
|
|
bits = 0; \
|
|
} while (0)
|
|
|
|
/* Get a byte of input into the bit accumulator, or return from inflate()
|
|
if there is no input available. */
|
|
#define PULLBYTE() \
|
|
do { \
|
|
if (have == 0) goto inf_leave; \
|
|
have--; \
|
|
hold += (unsigned long)(*next++) << bits; \
|
|
bits += 8; \
|
|
} while (0)
|
|
|
|
/* Assure that there are at least n bits in the bit accumulator. If there is
|
|
not enough available input to do that, then return from inflate(). */
|
|
#define NEEDBITS(n) \
|
|
do { \
|
|
while (bits < (unsigned)(n)) \
|
|
PULLBYTE(); \
|
|
} while (0)
|
|
|
|
/* Return the low n bits of the bit accumulator (n < 16) */
|
|
#define BITS(n) \
|
|
((unsigned)hold & ((1U << (n)) - 1))
|
|
|
|
/* Remove n bits from the bit accumulator */
|
|
#define DROPBITS(n) \
|
|
do { \
|
|
hold >>= (n); \
|
|
bits -= (unsigned)(n); \
|
|
} while (0)
|
|
|
|
/* Remove zero to seven bits as needed to go to a byte boundary */
|
|
#define BYTEBITS() \
|
|
do { \
|
|
hold >>= bits & 7; \
|
|
bits -= bits & 7; \
|
|
} while (0)
|
|
|
|
/*
|
|
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(strm, flush)
|
|
z_streamp strm;
|
|
int flush;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
z_const unsigned char FAR *next; /* next input */
|
|
unsigned char FAR *put; /* next output */
|
|
unsigned have, left; /* available input and output */
|
|
unsigned long hold; /* bit buffer */
|
|
unsigned bits; /* bits in bit buffer */
|
|
unsigned in, out; /* save starting available input and output */
|
|
unsigned copy; /* number of stored or match bytes to copy */
|
|
unsigned char FAR *from; /* where to copy match bytes from */
|
|
code here; /* current decoding table entry */
|
|
code last; /* parent table entry */
|
|
unsigned len; /* length to copy for repeats, bits to drop */
|
|
int ret; /* return code */
|
|
#ifdef GUNZIP
|
|
unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
|
|
#endif
|
|
static const unsigned short order[19] = /* permutation of code lengths */
|
|
{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
|
|
|
|
if (inflateStateCheck(strm) || 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 */
|
|
if (state->wbits == 0)
|
|
state->wbits = 15;
|
|
state->check = crc32(0L, Z_NULL, 0);
|
|
CRC2(state->check, hold);
|
|
INITBITS();
|
|
state->mode = FLAGS;
|
|
break;
|
|
}
|
|
state->flags = 0; /* expect zlib header */
|
|
if (state->head != Z_NULL)
|
|
state->head->done = -1;
|
|
if (!(state->wrap & 1) || /* check if zlib header allowed */
|
|
#else
|
|
if (
|
|
#endif
|
|
((BITS(8) << 8) + (hold >> 8)) % 31) {
|
|
strm->msg = (char *)"incorrect header check";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
if (BITS(4) != Z_DEFLATED) {
|
|
strm->msg = (char *)"unknown compression method";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
DROPBITS(4);
|
|
len = BITS(4) + 8;
|
|
if (state->wbits == 0)
|
|
state->wbits = len;
|
|
if (len > 15 || len > state->wbits) {
|
|
strm->msg = (char *)"invalid window size";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
state->dmax = 1U << len;
|
|
Tracev((stderr, "inflate: zlib header ok\n"));
|
|
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) {
|
|
strm->msg = (char *)"unknown compression method";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
if (state->flags & 0xe000) {
|
|
strm->msg = (char *)"unknown header flags set";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
if (state->head != Z_NULL)
|
|
state->head->text = (int)((hold >> 8) & 1);
|
|
if ((state->flags & 0x0200) && (state->wrap & 4))
|
|
CRC2(state->check, hold);
|
|
INITBITS();
|
|
state->mode = TIME;
|
|
case TIME:
|
|
NEEDBITS(32);
|
|
if (state->head != Z_NULL)
|
|
state->head->time = hold;
|
|
if ((state->flags & 0x0200) && (state->wrap & 4))
|
|
CRC4(state->check, hold);
|
|
INITBITS();
|
|
state->mode = OS;
|
|
case OS:
|
|
NEEDBITS(16);
|
|
if (state->head != Z_NULL) {
|
|
state->head->xflags = (int)(hold & 0xff);
|
|
state->head->os = (int)(hold >> 8);
|
|
}
|
|
if ((state->flags & 0x0200) && (state->wrap & 4))
|
|
CRC2(state->check, hold);
|
|
INITBITS();
|
|
state->mode = EXLEN;
|
|
case EXLEN:
|
|
if (state->flags & 0x0400) {
|
|
NEEDBITS(16);
|
|
state->length = (unsigned)(hold);
|
|
if (state->head != Z_NULL)
|
|
state->head->extra_len = (unsigned)hold;
|
|
if ((state->flags & 0x0200) && (state->wrap & 4))
|
|
CRC2(state->check, hold);
|
|
INITBITS();
|
|
}
|
|
else if (state->head != Z_NULL)
|
|
state->head->extra = Z_NULL;
|
|
state->mode = EXTRA;
|
|
case EXTRA:
|
|
if (state->flags & 0x0400) {
|
|
copy = state->length;
|
|
if (copy > have) copy = have;
|
|
if (copy) {
|
|
if (state->head != Z_NULL &&
|
|
state->head->extra != Z_NULL) {
|
|
len = state->head->extra_len - state->length;
|
|
zmemcpy(state->head->extra + len, next,
|
|
len + copy > state->head->extra_max ?
|
|
state->head->extra_max - len : copy);
|
|
}
|
|
if ((state->flags & 0x0200) && (state->wrap & 4))
|
|
state->check = crc32(state->check, next, copy);
|
|
have -= copy;
|
|
next += copy;
|
|
state->length -= copy;
|
|
}
|
|
if (state->length) goto inf_leave;
|
|
}
|
|
state->length = 0;
|
|
state->mode = NAME;
|
|
case NAME:
|
|
if (state->flags & 0x0800) {
|
|
if (have == 0) goto inf_leave;
|
|
copy = 0;
|
|
do {
|
|
len = (unsigned)(next[copy++]);
|
|
if (state->head != Z_NULL &&
|
|
state->head->name != Z_NULL &&
|
|
state->length < state->head->name_max)
|
|
state->head->name[state->length++] = (Bytef)len;
|
|
} while (len && copy < have);
|
|
if ((state->flags & 0x0200) && (state->wrap & 4))
|
|
state->check = crc32(state->check, next, copy);
|
|
have -= copy;
|
|
next += copy;
|
|
if (len) goto inf_leave;
|
|
}
|
|
else if (state->head != Z_NULL)
|
|
state->head->name = Z_NULL;
|
|
state->length = 0;
|
|
state->mode = COMMENT;
|
|
case COMMENT:
|
|
if (state->flags & 0x1000) {
|
|
if (have == 0) goto inf_leave;
|
|
copy = 0;
|
|
do {
|
|
len = (unsigned)(next[copy++]);
|
|
if (state->head != Z_NULL &&
|
|
state->head->comment != Z_NULL &&
|
|
state->length < state->head->comm_max)
|
|
state->head->comment[state->length++] = (Bytef)len;
|
|
} while (len && copy < have);
|
|
if ((state->flags & 0x0200) && (state->wrap & 4))
|
|
state->check = crc32(state->check, next, copy);
|
|
have -= copy;
|
|
next += copy;
|
|
if (len) goto inf_leave;
|
|
}
|
|
else if (state->head != Z_NULL)
|
|
state->head->comment = Z_NULL;
|
|
state->mode = HCRC;
|
|
case HCRC:
|
|
if (state->flags & 0x0200) {
|
|
NEEDBITS(16);
|
|
if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
|
|
strm->msg = (char *)"header crc mismatch";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
INITBITS();
|
|
}
|
|
if (state->head != Z_NULL) {
|
|
state->head->hcrc = (int)((state->flags >> 9) & 1);
|
|
state->head->done = 1;
|
|
}
|
|
strm->adler = state->check = crc32(0L, Z_NULL, 0);
|
|
state->mode = TYPE;
|
|
break;
|
|
#endif
|
|
case DICTID:
|
|
NEEDBITS(32);
|
|
strm->adler = state->check = ZSWAP32(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 || flush == Z_TREES) 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 */
|
|
Tracev((stderr, "inflate: stored block%s\n",
|
|
state->last ? " (last)" : ""));
|
|
state->mode = STORED;
|
|
break;
|
|
case 1: /* fixed block */
|
|
fixedtables(state);
|
|
Tracev((stderr, "inflate: fixed codes block%s\n",
|
|
state->last ? " (last)" : ""));
|
|
state->mode = LEN_; /* decode codes */
|
|
if (flush == Z_TREES) {
|
|
DROPBITS(2);
|
|
goto inf_leave;
|
|
}
|
|
break;
|
|
case 2: /* dynamic block */
|
|
Tracev((stderr, "inflate: dynamic codes block%s\n",
|
|
state->last ? " (last)" : ""));
|
|
state->mode = TABLE;
|
|
break;
|
|
case 3:
|
|
strm->msg = (char *)"invalid block type";
|
|
state->mode = BAD;
|
|
}
|
|
DROPBITS(2);
|
|
break;
|
|
case STORED:
|
|
BYTEBITS(); /* go to byte boundary */
|
|
NEEDBITS(32);
|
|
if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
|
|
strm->msg = (char *)"invalid stored block lengths";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
state->length = (unsigned)hold & 0xffff;
|
|
Tracev((stderr, "inflate: stored length %u\n",
|
|
state->length));
|
|
INITBITS();
|
|
state->mode = COPY_;
|
|
if (flush == Z_TREES) goto inf_leave;
|
|
case COPY_:
|
|
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;
|
|
}
|
|
Tracev((stderr, "inflate: stored end\n"));
|
|
state->mode = TYPE;
|
|
break;
|
|
case TABLE:
|
|
NEEDBITS(14);
|
|
state->nlen = BITS(5) + 257;
|
|
DROPBITS(5);
|
|
state->ndist = BITS(5) + 1;
|
|
DROPBITS(5);
|
|
state->ncode = BITS(4) + 4;
|
|
DROPBITS(4);
|
|
#ifndef PKZIP_BUG_WORKAROUND
|
|
if (state->nlen > 286 || state->ndist > 30) {
|
|
strm->msg = (char *)"too many length or distance symbols";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
#endif
|
|
Tracev((stderr, "inflate: table sizes ok\n"));
|
|
state->have = 0;
|
|
state->mode = LENLENS;
|
|
case LENLENS:
|
|
while (state->have < state->ncode) {
|
|
NEEDBITS(3);
|
|
state->lens[order[state->have++]] = (unsigned short)BITS(3);
|
|
DROPBITS(3);
|
|
}
|
|
while (state->have < 19)
|
|
state->lens[order[state->have++]] = 0;
|
|
state->next = state->codes;
|
|
state->lencode = (const code FAR *)(state->next);
|
|
state->lenbits = 7;
|
|
ret = inflate_table(CODES, state->lens, 19, &(state->next),
|
|
&(state->lenbits), state->work);
|
|
if (ret) {
|
|
strm->msg = (char *)"invalid code lengths set";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
Tracev((stderr, "inflate: code lengths ok\n"));
|
|
state->have = 0;
|
|
state->mode = CODELENS;
|
|
case CODELENS:
|
|
while (state->have < state->nlen + state->ndist) {
|
|
for (;;) {
|
|
here = state->lencode[BITS(state->lenbits)];
|
|
if ((unsigned)(here.bits) <= bits) break;
|
|
PULLBYTE();
|
|
}
|
|
if (here.val < 16) {
|
|
DROPBITS(here.bits);
|
|
state->lens[state->have++] = here.val;
|
|
}
|
|
else {
|
|
if (here.val == 16) {
|
|
NEEDBITS(here.bits + 2);
|
|
DROPBITS(here.bits);
|
|
if (state->have == 0) {
|
|
strm->msg = (char *)"invalid bit length repeat";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
len = state->lens[state->have - 1];
|
|
copy = 3 + BITS(2);
|
|
DROPBITS(2);
|
|
}
|
|
else if (here.val == 17) {
|
|
NEEDBITS(here.bits + 3);
|
|
DROPBITS(here.bits);
|
|
len = 0;
|
|
copy = 3 + BITS(3);
|
|
DROPBITS(3);
|
|
}
|
|
else {
|
|
NEEDBITS(here.bits + 7);
|
|
DROPBITS(here.bits);
|
|
len = 0;
|
|
copy = 11 + BITS(7);
|
|
DROPBITS(7);
|
|
}
|
|
if (state->have + copy > state->nlen + state->ndist) {
|
|
strm->msg = (char *)"invalid bit length repeat";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
while (copy--)
|
|
state->lens[state->have++] = (unsigned short)len;
|
|
}
|
|
}
|
|
|
|
/* handle error breaks in while */
|
|
if (state->mode == BAD) break;
|
|
|
|
/* check for end-of-block code (better have one) */
|
|
if (state->lens[256] == 0) {
|
|
strm->msg = (char *)"invalid code -- missing end-of-block";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
|
|
/* build code tables -- note: do not change the lenbits or distbits
|
|
values here (9 and 6) without reading the comments in inftrees.h
|
|
concerning the ENOUGH constants, which depend on those values */
|
|
state->next = state->codes;
|
|
state->lencode = (const code FAR *)(state->next);
|
|
state->lenbits = 9;
|
|
ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
|
|
&(state->lenbits), state->work);
|
|
if (ret) {
|
|
strm->msg = (char *)"invalid literal/lengths set";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
state->distcode = (const code FAR *)(state->next);
|
|
state->distbits = 6;
|
|
ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
|
|
&(state->next), &(state->distbits), state->work);
|
|
if (ret) {
|
|
strm->msg = (char *)"invalid distances set";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
Tracev((stderr, "inflate: codes ok\n"));
|
|
state->mode = LEN_;
|
|
if (flush == Z_TREES) goto inf_leave;
|
|
case LEN_:
|
|
state->mode = LEN;
|
|
case LEN:
|
|
if (have >= 6 && left >= 258) {
|
|
RESTORE();
|
|
inflate_fast(strm, out);
|
|
LOAD();
|
|
if (state->mode == TYPE)
|
|
state->back = -1;
|
|
break;
|
|
}
|
|
state->back = 0;
|
|
for (;;) {
|
|
here = state->lencode[BITS(state->lenbits)];
|
|
if ((unsigned)(here.bits) <= bits) break;
|
|
PULLBYTE();
|
|
}
|
|
if (here.op && (here.op & 0xf0) == 0) {
|
|
last = here;
|
|
for (;;) {
|
|
here = state->lencode[last.val +
|
|
(BITS(last.bits + last.op) >> last.bits)];
|
|
if ((unsigned)(last.bits + here.bits) <= bits) break;
|
|
PULLBYTE();
|
|
}
|
|
DROPBITS(last.bits);
|
|
state->back += last.bits;
|
|
}
|
|
DROPBITS(here.bits);
|
|
state->back += here.bits;
|
|
state->length = (unsigned)here.val;
|
|
if ((int)(here.op) == 0) {
|
|
Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
|
|
"inflate: literal '%c'\n" :
|
|
"inflate: literal 0x%02x\n", here.val));
|
|
state->mode = LIT;
|
|
break;
|
|
}
|
|
if (here.op & 32) {
|
|
Tracevv((stderr, "inflate: end of block\n"));
|
|
state->back = -1;
|
|
state->mode = TYPE;
|
|
break;
|
|
}
|
|
if (here.op & 64) {
|
|
strm->msg = (char *)"invalid literal/length code";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
state->extra = (unsigned)(here.op) & 15;
|
|
state->mode = LENEXT;
|
|
case LENEXT:
|
|
if (state->extra) {
|
|
NEEDBITS(state->extra);
|
|
state->length += BITS(state->extra);
|
|
DROPBITS(state->extra);
|
|
state->back += state->extra;
|
|
}
|
|
Tracevv((stderr, "inflate: length %u\n", state->length));
|
|
state->was = state->length;
|
|
state->mode = DIST;
|
|
case DIST:
|
|
for (;;) {
|
|
here = state->distcode[BITS(state->distbits)];
|
|
if ((unsigned)(here.bits) <= bits) break;
|
|
PULLBYTE();
|
|
}
|
|
if ((here.op & 0xf0) == 0) {
|
|
last = here;
|
|
for (;;) {
|
|
here = state->distcode[last.val +
|
|
(BITS(last.bits + last.op) >> last.bits)];
|
|
if ((unsigned)(last.bits + here.bits) <= bits) break;
|
|
PULLBYTE();
|
|
}
|
|
DROPBITS(last.bits);
|
|
state->back += last.bits;
|
|
}
|
|
DROPBITS(here.bits);
|
|
state->back += here.bits;
|
|
if (here.op & 64) {
|
|
strm->msg = (char *)"invalid distance code";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
state->offset = (unsigned)here.val;
|
|
state->extra = (unsigned)(here.op) & 15;
|
|
state->mode = DISTEXT;
|
|
case DISTEXT:
|
|
if (state->extra) {
|
|
NEEDBITS(state->extra);
|
|
state->offset += BITS(state->extra);
|
|
DROPBITS(state->extra);
|
|
state->back += state->extra;
|
|
}
|
|
#ifdef INFLATE_STRICT
|
|
if (state->offset > state->dmax) {
|
|
strm->msg = (char *)"invalid distance too far back";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
#endif
|
|
Tracevv((stderr, "inflate: distance %u\n", state->offset));
|
|
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->whave) {
|
|
if (state->sane) {
|
|
strm->msg = (char *)"invalid distance too far back";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
|
|
Trace((stderr, "inflate.c too far\n"));
|
|
copy -= state->whave;
|
|
if (copy > state->length) copy = state->length;
|
|
if (copy > left) copy = left;
|
|
left -= copy;
|
|
state->length -= copy;
|
|
do {
|
|
*put++ = 0;
|
|
} while (--copy);
|
|
if (state->length == 0) state->mode = LEN;
|
|
break;
|
|
#endif
|
|
}
|
|
if (copy > state->wnext) {
|
|
copy -= state->wnext;
|
|
from = state->window + (state->wsize - copy);
|
|
}
|
|
else
|
|
from = state->window + (state->wnext - copy);
|
|
if (copy > state->length) copy = state->length;
|
|
}
|
|
else { /* copy from output */
|
|
from = put - state->offset;
|
|
copy = state->length;
|
|
}
|
|
if (copy > left) copy = left;
|
|
left -= copy;
|
|
state->length -= copy;
|
|
do {
|
|
*put++ = *from++;
|
|
} while (--copy);
|
|
if (state->length == 0) state->mode = LEN;
|
|
break;
|
|
case LIT:
|
|
if (left == 0) goto inf_leave;
|
|
*put++ = (unsigned char)(state->length);
|
|
left--;
|
|
state->mode = LEN;
|
|
break;
|
|
case CHECK:
|
|
if (state->wrap) {
|
|
NEEDBITS(32);
|
|
out -= left;
|
|
strm->total_out += out;
|
|
state->total += out;
|
|
if ((state->wrap & 4) && out)
|
|
strm->adler = state->check =
|
|
UPDATE(state->check, put - out, out);
|
|
out = left;
|
|
if ((state->wrap & 4) && (
|
|
#ifdef GUNZIP
|
|
state->flags ? hold :
|
|
#endif
|
|
ZSWAP32(hold)) != state->check) {
|
|
strm->msg = (char *)"incorrect data check";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
INITBITS();
|
|
Tracev((stderr, "inflate: check matches trailer\n"));
|
|
}
|
|
#ifdef GUNZIP
|
|
state->mode = LENGTH;
|
|
case LENGTH:
|
|
if (state->wrap && state->flags) {
|
|
NEEDBITS(32);
|
|
if (hold != (state->total & 0xffffffffUL)) {
|
|
strm->msg = (char *)"incorrect length check";
|
|
state->mode = BAD;
|
|
break;
|
|
}
|
|
INITBITS();
|
|
Tracev((stderr, "inflate: length matches trailer\n"));
|
|
}
|
|
#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 || (out != strm->avail_out && state->mode < BAD &&
|
|
(state->mode < CHECK || flush != Z_FINISH)))
|
|
if (updatewindow(strm, strm->next_out, out - strm->avail_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 & 4) && out)
|
|
strm->adler = state->check =
|
|
UPDATE(state->check, strm->next_out - out, out);
|
|
strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
|
|
(state->mode == TYPE ? 128 : 0) +
|
|
(state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
|
|
if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
|
|
ret = Z_BUF_ERROR;
|
|
return ret;
|
|
}
|
|
|
|
int ZEXPORT inflateEnd(strm)
|
|
z_streamp strm;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
if (inflateStateCheck(strm))
|
|
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;
|
|
Tracev((stderr, "inflate: end\n"));
|
|
return Z_OK;
|
|
}
|
|
|
|
int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
|
|
z_streamp strm;
|
|
Bytef *dictionary;
|
|
uInt *dictLength;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
|
|
/* check state */
|
|
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
|
|
state = (struct inflate_state FAR *)strm->state;
|
|
|
|
/* copy dictionary */
|
|
if (state->whave && dictionary != Z_NULL) {
|
|
zmemcpy(dictionary, state->window + state->wnext,
|
|
state->whave - state->wnext);
|
|
zmemcpy(dictionary + state->whave - state->wnext,
|
|
state->window, state->wnext);
|
|
}
|
|
if (dictLength != Z_NULL)
|
|
*dictLength = state->whave;
|
|
return Z_OK;
|
|
}
|
|
|
|
int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
|
|
z_streamp strm;
|
|
const Bytef *dictionary;
|
|
uInt dictLength;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
unsigned long dictid;
|
|
int ret;
|
|
|
|
/* check state */
|
|
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
|
|
state = (struct inflate_state FAR *)strm->state;
|
|
if (state->wrap != 0 && state->mode != DICT)
|
|
return Z_STREAM_ERROR;
|
|
|
|
/* check for correct dictionary identifier */
|
|
if (state->mode == DICT) {
|
|
dictid = adler32(0L, Z_NULL, 0);
|
|
dictid = adler32(dictid, dictionary, dictLength);
|
|
if (dictid != state->check)
|
|
return Z_DATA_ERROR;
|
|
}
|
|
|
|
/* copy dictionary to window using updatewindow(), which will amend the
|
|
existing dictionary if appropriate */
|
|
ret = updatewindow(strm, dictionary + dictLength, dictLength);
|
|
if (ret) {
|
|
state->mode = MEM;
|
|
return Z_MEM_ERROR;
|
|
}
|
|
state->havedict = 1;
|
|
Tracev((stderr, "inflate: dictionary set\n"));
|
|
return Z_OK;
|
|
}
|
|
|
|
int ZEXPORT inflateGetHeader(strm, head)
|
|
z_streamp strm;
|
|
gz_headerp head;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
|
|
/* check state */
|
|
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
|
|
state = (struct inflate_state FAR *)strm->state;
|
|
if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
|
|
|
|
/* save header structure */
|
|
state->head = head;
|
|
head->done = 0;
|
|
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.
|
|
*/
|
|
local unsigned syncsearch(have, buf, len)
|
|
unsigned FAR *have;
|
|
const unsigned char FAR *buf;
|
|
unsigned len;
|
|
{
|
|
unsigned got;
|
|
unsigned 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(strm)
|
|
z_streamp strm;
|
|
{
|
|
unsigned len; /* number of bytes to look at or looked at */
|
|
unsigned long in, out; /* temporary to save total_in and total_out */
|
|
unsigned char buf[4]; /* to restore bit buffer to byte string */
|
|
struct inflate_state FAR *state;
|
|
|
|
/* check parameters */
|
|
if (inflateStateCheck(strm)) 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++] = (unsigned char)(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(strm)
|
|
z_streamp strm;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
|
|
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
|
|
state = (struct inflate_state FAR *)strm->state;
|
|
return state->mode == STORED && state->bits == 0;
|
|
}
|
|
|
|
int ZEXPORT inflateCopy(dest, source)
|
|
z_streamp dest;
|
|
z_streamp source;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
struct inflate_state FAR *copy;
|
|
unsigned char FAR *window;
|
|
unsigned wsize;
|
|
|
|
/* check input */
|
|
if (inflateStateCheck(source) || dest == Z_NULL)
|
|
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 = (unsigned char FAR *)
|
|
ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
|
|
if (window == Z_NULL) {
|
|
ZFREE(source, copy);
|
|
return Z_MEM_ERROR;
|
|
}
|
|
}
|
|
|
|
/* copy state */
|
|
zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
|
|
zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
|
|
copy->strm = dest;
|
|
if (state->lencode >= state->codes &&
|
|
state->lencode <= state->codes + ENOUGH - 1) {
|
|
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) {
|
|
wsize = 1U << state->wbits;
|
|
zmemcpy(window, state->window, wsize);
|
|
}
|
|
copy->window = window;
|
|
dest->state = (struct internal_state FAR *)copy;
|
|
return Z_OK;
|
|
}
|
|
|
|
int ZEXPORT inflateUndermine(strm, subvert)
|
|
z_streamp strm;
|
|
int subvert;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
|
|
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
|
|
state = (struct inflate_state FAR *)strm->state;
|
|
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
|
|
state->sane = !subvert;
|
|
return Z_OK;
|
|
#else
|
|
(void)subvert;
|
|
state->sane = 1;
|
|
return Z_DATA_ERROR;
|
|
#endif
|
|
}
|
|
|
|
int ZEXPORT inflateValidate(strm, check)
|
|
z_streamp strm;
|
|
int check;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
|
|
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
|
|
state = (struct inflate_state FAR *)strm->state;
|
|
if (check)
|
|
state->wrap |= 4;
|
|
else
|
|
state->wrap &= ~4;
|
|
return Z_OK;
|
|
}
|
|
|
|
long ZEXPORT inflateMark(strm)
|
|
z_streamp strm;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
|
|
if (inflateStateCheck(strm))
|
|
return -(1L << 16);
|
|
state = (struct inflate_state FAR *)strm->state;
|
|
return (long)(((unsigned long)((long)state->back)) << 16) +
|
|
(state->mode == COPY ? state->length :
|
|
(state->mode == MATCH ? state->was - state->length : 0));
|
|
}
|
|
|
|
unsigned long ZEXPORT inflateCodesUsed(strm)
|
|
z_streamp strm;
|
|
{
|
|
struct inflate_state FAR *state;
|
|
if (inflateStateCheck(strm)) return (unsigned long)-1;
|
|
state = (struct inflate_state FAR *)strm->state;
|
|
return (unsigned long)(state->next - state->codes);
|
|
}
|