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1561 lines
54 KiB
1561 lines
54 KiB
/* 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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/* |
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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/* |
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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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|
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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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|
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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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|
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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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|
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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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|
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Then that can be linked with zlib built with MAKEFIXED defined and run: |
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|
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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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/* |
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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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|
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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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|
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state = (struct inflate_state FAR *)strm->state; |
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|
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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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|
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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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|
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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 |
|
|
|
/* 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) |
|
|
|
# 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); \ |
|
} while (0) |
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#endif |
|
|
|
/* Load registers with state in inflate() for speed */ |
|
#define LOAD() \ |
|
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) |
|
|
|
/* Restore state from registers in inflate() */ |
|
#define RESTORE() \ |
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do { \ |
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strm->next_out = put; \ |
|
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() \ |
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do { \ |
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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) \ |
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do { \ |
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while (bits < (unsigned)(n)) \ |
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PULLBYTE(); \ |
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} while (0) |
|
|
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/* Return the low n bits of the bit accumulator (n < 16) */ |
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#define BITS(n) \ |
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((unsigned)hold & ((1U << (n)) - 1)) |
|
|
|
/* Remove n bits from the bit accumulator */ |
|
#define DROPBITS(n) \ |
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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); |
|
}
|
|
|