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640 lines
22 KiB
640 lines
22 KiB
/* infback.c -- inflate using a call-back interface |
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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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This code is largely copied from inflate.c. Normally either infback.o or |
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inflate.o would be linked into an application--not both. The interface |
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with inffast.c is retained so that optimized assembler-coded versions of |
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inflate_fast() can be used with either inflate.c or infback.c. |
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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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/* function prototypes */ |
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local void fixedtables OF((struct inflate_state FAR *state)); |
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|
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/* |
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strm provides memory allocation functions in zalloc and zfree, or |
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Z_NULL to use the library memory allocation functions. |
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|
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windowBits is in the range 8..15, and window is a user-supplied |
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window and output buffer that is 2**windowBits bytes. |
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*/ |
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int ZEXPORT inflateBackInit_(strm, windowBits, window, version, stream_size) |
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z_streamp strm; |
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int windowBits; |
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unsigned char FAR *window; |
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const char *version; |
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int stream_size; |
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{ |
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struct inflate_state FAR *state; |
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|
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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 || window == Z_NULL || |
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windowBits < 8 || windowBits > 15) |
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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 *)ZALLOC(strm, 1, |
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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->dmax = 32768U; |
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state->wbits = (uInt)windowBits; |
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state->wsize = 1U << windowBits; |
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state->window = window; |
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state->wnext = 0; |
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state->whave = 0; |
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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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|
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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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|
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/* Macros for inflateBack(): */ |
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|
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/* Load returned state from inflate_fast() */ |
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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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/* Set state from registers for inflate_fast() */ |
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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; \ |
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} while (0) |
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|
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/* Clear the input bit accumulator */ |
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#define INITBITS() \ |
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do { \ |
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hold = 0; \ |
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bits = 0; \ |
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} while (0) |
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|
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/* Assure that some input is available. If input is requested, but denied, |
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then return a Z_BUF_ERROR from inflateBack(). */ |
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#define PULL() \ |
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do { \ |
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if (have == 0) { \ |
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have = in(in_desc, &next); \ |
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if (have == 0) { \ |
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next = Z_NULL; \ |
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ret = Z_BUF_ERROR; \ |
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goto inf_leave; \ |
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} \ |
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} \ |
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} while (0) |
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|
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/* Get a byte of input into the bit accumulator, or return from inflateBack() |
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with an error if there is no input available. */ |
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#define PULLBYTE() \ |
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do { \ |
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PULL(); \ |
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have--; \ |
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hold += (unsigned long)(*next++) << bits; \ |
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bits += 8; \ |
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} while (0) |
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|
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/* Assure that there are at least n bits in the bit accumulator. If there is |
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not enough available input to do that, then return from inflateBack() with |
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an error. */ |
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#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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|
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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)) |
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|
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/* Remove n bits from the bit accumulator */ |
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#define DROPBITS(n) \ |
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do { \ |
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hold >>= (n); \ |
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bits -= (unsigned)(n); \ |
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} while (0) |
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|
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/* Remove zero to seven bits as needed to go to a byte boundary */ |
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#define BYTEBITS() \ |
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do { \ |
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hold >>= bits & 7; \ |
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bits -= bits & 7; \ |
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} while (0) |
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|
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/* Assure that some output space is available, by writing out the window |
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if it's full. If the write fails, return from inflateBack() with a |
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Z_BUF_ERROR. */ |
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#define ROOM() \ |
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do { \ |
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if (left == 0) { \ |
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put = state->window; \ |
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left = state->wsize; \ |
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state->whave = left; \ |
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if (out(out_desc, put, left)) { \ |
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ret = Z_BUF_ERROR; \ |
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goto inf_leave; \ |
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} \ |
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} \ |
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} while (0) |
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|
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/* |
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strm provides the memory allocation functions and window buffer on input, |
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and provides information on the unused input on return. For Z_DATA_ERROR |
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returns, strm will also provide an error message. |
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|
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in() and out() are the call-back input and output functions. When |
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inflateBack() needs more input, it calls in(). When inflateBack() has |
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filled the window with output, or when it completes with data in the |
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window, it calls out() to write out the data. The application must not |
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change the provided input until in() is called again or inflateBack() |
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returns. The application must not change the window/output buffer until |
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inflateBack() returns. |
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|
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in() and out() are called with a descriptor parameter provided in the |
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inflateBack() call. This parameter can be a structure that provides the |
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information required to do the read or write, as well as accumulated |
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information on the input and output such as totals and check values. |
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|
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in() should return zero on failure. out() should return non-zero on |
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failure. If either in() or out() fails, than inflateBack() returns a |
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Z_BUF_ERROR. strm->next_in can be checked for Z_NULL to see whether it |
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was in() or out() that caused in the error. Otherwise, inflateBack() |
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returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format |
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error, or Z_MEM_ERROR if it could not allocate memory for the state. |
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inflateBack() can also return Z_STREAM_ERROR if the input parameters |
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are not correct, i.e. strm is Z_NULL or the state was not initialized. |
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*/ |
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int ZEXPORT inflateBack(strm, in, in_desc, out, out_desc) |
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z_streamp strm; |
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in_func in; |
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void FAR *in_desc; |
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out_func out; |
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void FAR *out_desc; |
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{ |
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struct inflate_state FAR *state; |
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z_const unsigned char FAR *next; /* next input */ |
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unsigned char FAR *put; /* next output */ |
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unsigned have, left; /* available input and output */ |
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unsigned long hold; /* bit buffer */ |
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unsigned bits; /* bits in bit buffer */ |
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unsigned copy; /* number of stored or match bytes to copy */ |
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unsigned char FAR *from; /* where to copy match bytes from */ |
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code here; /* current decoding table entry */ |
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code last; /* parent table entry */ |
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unsigned len; /* length to copy for repeats, bits to drop */ |
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int ret; /* return code */ |
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static const unsigned short order[19] = /* permutation of code lengths */ |
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{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; |
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|
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/* Check that the strm exists and that the state was initialized */ |
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if (strm == Z_NULL || strm->state == Z_NULL) |
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return Z_STREAM_ERROR; |
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state = (struct inflate_state FAR *)strm->state; |
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|
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/* Reset the state */ |
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strm->msg = Z_NULL; |
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state->mode = TYPE; |
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state->last = 0; |
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state->whave = 0; |
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next = strm->next_in; |
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have = next != Z_NULL ? strm->avail_in : 0; |
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hold = 0; |
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bits = 0; |
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put = state->window; |
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left = state->wsize; |
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|
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/* Inflate until end of block marked as last */ |
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for (;;) |
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switch (state->mode) { |
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case TYPE: |
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/* determine and dispatch block type */ |
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if (state->last) { |
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BYTEBITS(); |
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state->mode = DONE; |
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break; |
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} |
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NEEDBITS(3); |
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state->last = BITS(1); |
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DROPBITS(1); |
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switch (BITS(2)) { |
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case 0: /* stored block */ |
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Tracev((stderr, "inflate: stored block%s\n", |
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state->last ? " (last)" : "")); |
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state->mode = STORED; |
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break; |
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case 1: /* fixed block */ |
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fixedtables(state); |
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Tracev((stderr, "inflate: fixed codes block%s\n", |
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state->last ? " (last)" : "")); |
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state->mode = LEN; /* decode codes */ |
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break; |
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case 2: /* dynamic block */ |
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Tracev((stderr, "inflate: dynamic codes block%s\n", |
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state->last ? " (last)" : "")); |
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state->mode = TABLE; |
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break; |
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case 3: |
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strm->msg = (char *)"invalid block type"; |
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state->mode = BAD; |
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} |
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DROPBITS(2); |
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break; |
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|
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case STORED: |
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/* get and verify stored block length */ |
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BYTEBITS(); /* go to byte boundary */ |
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NEEDBITS(32); |
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if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { |
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strm->msg = (char *)"invalid stored block lengths"; |
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state->mode = BAD; |
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break; |
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} |
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state->length = (unsigned)hold & 0xffff; |
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Tracev((stderr, "inflate: stored length %u\n", |
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state->length)); |
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INITBITS(); |
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|
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/* copy stored block from input to output */ |
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while (state->length != 0) { |
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copy = state->length; |
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PULL(); |
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ROOM(); |
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if (copy > have) copy = have; |
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if (copy > left) copy = left; |
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zmemcpy(put, next, copy); |
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have -= copy; |
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next += copy; |
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left -= copy; |
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put += copy; |
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state->length -= copy; |
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} |
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Tracev((stderr, "inflate: stored end\n")); |
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state->mode = TYPE; |
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break; |
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|
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case TABLE: |
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/* get dynamic table entries descriptor */ |
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NEEDBITS(14); |
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state->nlen = BITS(5) + 257; |
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DROPBITS(5); |
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state->ndist = BITS(5) + 1; |
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DROPBITS(5); |
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state->ncode = BITS(4) + 4; |
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DROPBITS(4); |
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#ifndef PKZIP_BUG_WORKAROUND |
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if (state->nlen > 286 || state->ndist > 30) { |
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strm->msg = (char *)"too many length or distance symbols"; |
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state->mode = BAD; |
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break; |
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} |
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#endif |
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Tracev((stderr, "inflate: table sizes ok\n")); |
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|
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/* get code length code lengths (not a typo) */ |
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state->have = 0; |
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while (state->have < state->ncode) { |
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NEEDBITS(3); |
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state->lens[order[state->have++]] = (unsigned short)BITS(3); |
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DROPBITS(3); |
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} |
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while (state->have < 19) |
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state->lens[order[state->have++]] = 0; |
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state->next = state->codes; |
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state->lencode = (code const FAR *)(state->next); |
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state->lenbits = 7; |
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ret = inflate_table(CODES, state->lens, 19, &(state->next), |
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&(state->lenbits), state->work); |
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if (ret) { |
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strm->msg = (char *)"invalid code lengths set"; |
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state->mode = BAD; |
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break; |
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} |
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Tracev((stderr, "inflate: code lengths ok\n")); |
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|
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/* get length and distance code code lengths */ |
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state->have = 0; |
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while (state->have < state->nlen + state->ndist) { |
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for (;;) { |
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here = state->lencode[BITS(state->lenbits)]; |
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if ((unsigned)(here.bits) <= bits) break; |
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PULLBYTE(); |
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} |
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if (here.val < 16) { |
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DROPBITS(here.bits); |
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state->lens[state->have++] = here.val; |
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} |
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else { |
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if (here.val == 16) { |
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NEEDBITS(here.bits + 2); |
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DROPBITS(here.bits); |
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if (state->have == 0) { |
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strm->msg = (char *)"invalid bit length repeat"; |
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state->mode = BAD; |
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break; |
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} |
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len = (unsigned)(state->lens[state->have - 1]); |
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copy = 3 + BITS(2); |
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DROPBITS(2); |
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} |
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else if (here.val == 17) { |
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NEEDBITS(here.bits + 3); |
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DROPBITS(here.bits); |
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len = 0; |
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copy = 3 + BITS(3); |
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DROPBITS(3); |
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} |
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else { |
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NEEDBITS(here.bits + 7); |
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DROPBITS(here.bits); |
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len = 0; |
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copy = 11 + BITS(7); |
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DROPBITS(7); |
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} |
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if (state->have + copy > state->nlen + state->ndist) { |
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strm->msg = (char *)"invalid bit length repeat"; |
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state->mode = BAD; |
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break; |
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} |
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while (copy--) |
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state->lens[state->have++] = (unsigned short)len; |
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} |
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} |
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|
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/* handle error breaks in while */ |
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if (state->mode == BAD) break; |
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|
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/* check for end-of-block code (better have one) */ |
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if (state->lens[256] == 0) { |
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strm->msg = (char *)"invalid code -- missing end-of-block"; |
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state->mode = BAD; |
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break; |
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} |
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|
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/* build code tables -- note: do not change the lenbits or distbits |
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values here (9 and 6) without reading the comments in inftrees.h |
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concerning the ENOUGH constants, which depend on those values */ |
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state->next = state->codes; |
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state->lencode = (code const FAR *)(state->next); |
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state->lenbits = 9; |
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ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), |
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&(state->lenbits), state->work); |
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if (ret) { |
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strm->msg = (char *)"invalid literal/lengths set"; |
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state->mode = BAD; |
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break; |
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} |
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state->distcode = (code const FAR *)(state->next); |
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state->distbits = 6; |
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ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, |
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&(state->next), &(state->distbits), state->work); |
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if (ret) { |
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strm->msg = (char *)"invalid distances set"; |
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state->mode = BAD; |
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break; |
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} |
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Tracev((stderr, "inflate: codes ok\n")); |
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state->mode = LEN; |
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|
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case LEN: |
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/* use inflate_fast() if we have enough input and output */ |
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if (have >= 6 && left >= 258) { |
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RESTORE(); |
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if (state->whave < state->wsize) |
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state->whave = state->wsize - left; |
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inflate_fast(strm, state->wsize); |
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LOAD(); |
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break; |
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} |
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|
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/* get a literal, length, or end-of-block code */ |
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for (;;) { |
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here = state->lencode[BITS(state->lenbits)]; |
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if ((unsigned)(here.bits) <= bits) break; |
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PULLBYTE(); |
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} |
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if (here.op && (here.op & 0xf0) == 0) { |
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last = here; |
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for (;;) { |
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here = state->lencode[last.val + |
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(BITS(last.bits + last.op) >> last.bits)]; |
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if ((unsigned)(last.bits + here.bits) <= bits) break; |
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PULLBYTE(); |
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} |
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DROPBITS(last.bits); |
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} |
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DROPBITS(here.bits); |
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state->length = (unsigned)here.val; |
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|
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/* process literal */ |
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if (here.op == 0) { |
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Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ? |
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"inflate: literal '%c'\n" : |
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"inflate: literal 0x%02x\n", here.val)); |
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ROOM(); |
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*put++ = (unsigned char)(state->length); |
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left--; |
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state->mode = LEN; |
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break; |
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} |
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|
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/* process end of block */ |
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if (here.op & 32) { |
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Tracevv((stderr, "inflate: end of block\n")); |
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state->mode = TYPE; |
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break; |
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} |
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|
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/* invalid code */ |
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if (here.op & 64) { |
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strm->msg = (char *)"invalid literal/length code"; |
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state->mode = BAD; |
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break; |
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} |
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|
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/* length code -- get extra bits, if any */ |
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state->extra = (unsigned)(here.op) & 15; |
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if (state->extra != 0) { |
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NEEDBITS(state->extra); |
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state->length += BITS(state->extra); |
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DROPBITS(state->extra); |
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} |
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Tracevv((stderr, "inflate: length %u\n", state->length)); |
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|
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/* get distance code */ |
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for (;;) { |
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here = state->distcode[BITS(state->distbits)]; |
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if ((unsigned)(here.bits) <= bits) break; |
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PULLBYTE(); |
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} |
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if ((here.op & 0xf0) == 0) { |
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last = here; |
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for (;;) { |
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here = state->distcode[last.val + |
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(BITS(last.bits + last.op) >> last.bits)]; |
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if ((unsigned)(last.bits + here.bits) <= bits) break; |
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PULLBYTE(); |
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} |
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DROPBITS(last.bits); |
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} |
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DROPBITS(here.bits); |
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if (here.op & 64) { |
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strm->msg = (char *)"invalid distance code"; |
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state->mode = BAD; |
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break; |
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} |
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state->offset = (unsigned)here.val; |
|
|
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/* get distance extra bits, if any */ |
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state->extra = (unsigned)(here.op) & 15; |
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if (state->extra != 0) { |
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NEEDBITS(state->extra); |
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state->offset += BITS(state->extra); |
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DROPBITS(state->extra); |
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} |
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if (state->offset > state->wsize - (state->whave < state->wsize ? |
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left : 0)) { |
|
strm->msg = (char *)"invalid distance too far back"; |
|
state->mode = BAD; |
|
break; |
|
} |
|
Tracevv((stderr, "inflate: distance %u\n", state->offset)); |
|
|
|
/* copy match from window to output */ |
|
do { |
|
ROOM(); |
|
copy = state->wsize - state->offset; |
|
if (copy < left) { |
|
from = put + copy; |
|
copy = left - copy; |
|
} |
|
else { |
|
from = put - state->offset; |
|
copy = left; |
|
} |
|
if (copy > state->length) copy = state->length; |
|
state->length -= copy; |
|
left -= copy; |
|
do { |
|
*put++ = *from++; |
|
} while (--copy); |
|
} while (state->length != 0); |
|
break; |
|
|
|
case DONE: |
|
/* inflate stream terminated properly -- write leftover output */ |
|
ret = Z_STREAM_END; |
|
if (left < state->wsize) { |
|
if (out(out_desc, state->window, state->wsize - left)) |
|
ret = Z_BUF_ERROR; |
|
} |
|
goto inf_leave; |
|
|
|
case BAD: |
|
ret = Z_DATA_ERROR; |
|
goto inf_leave; |
|
|
|
default: /* can't happen, but makes compilers happy */ |
|
ret = Z_STREAM_ERROR; |
|
goto inf_leave; |
|
} |
|
|
|
/* Return unused input */ |
|
inf_leave: |
|
strm->next_in = next; |
|
strm->avail_in = have; |
|
return ret; |
|
} |
|
|
|
int ZEXPORT inflateBackEnd(strm) |
|
z_streamp strm; |
|
{ |
|
if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0) |
|
return Z_STREAM_ERROR; |
|
ZFREE(strm, strm->state); |
|
strm->state = Z_NULL; |
|
Tracev((stderr, "inflate: end\n")); |
|
return Z_OK; |
|
}
|
|
|