88 lines
2.0 KiB
C
88 lines
2.0 KiB
C
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/* inflate_util.c -- data and routines common to blocks and codes
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* Copyright (C) 1995-1996 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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#include "zutil.h"
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#include "infblock.h"
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#include "inftrees.h"
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#include "infcodes.h"
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#include "infutil.h"
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struct inflate_codes_state {int dummy;}; /* for buggy compilers */
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/* And'ing with mask[n] masks the lower n bits */
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uInt inflate_mask[17] = {
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0x0000,
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0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
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0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
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};
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/* copy as much as possible from the sliding window to the output area */
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int inflate_flush(s, z, r)
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inflate_blocks_statef *s;
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z_streamp z;
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int r;
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{
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uInt n;
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Bytef *p;
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Bytef *q;
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/* local copies of source and destination pointers */
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p = z->next_out;
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q = s->read;
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/* compute number of bytes to copy as far as end of window */
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n = (uInt)((q <= s->write ? s->write : s->end) - q);
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if (n > z->avail_out) n = z->avail_out;
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if (n && r == Z_BUF_ERROR) r = Z_OK;
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/* update counters */
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z->avail_out -= n;
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z->total_out += n;
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/* update check information */
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if (s->checkfn != Z_NULL)
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z->adler = s->check = (*s->checkfn)(s->check, q, n);
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/* copy as far as end of window */
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zmemcpy(p, q, n);
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p += n;
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q += n;
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/* see if more to copy at beginning of window */
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if (q == s->end)
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{
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/* wrap pointers */
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q = s->window;
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if (s->write == s->end)
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s->write = s->window;
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/* compute bytes to copy */
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n = (uInt)(s->write - q);
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if (n > z->avail_out) n = z->avail_out;
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if (n && r == Z_BUF_ERROR) r = Z_OK;
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/* update counters */
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z->avail_out -= n;
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z->total_out += n;
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/* update check information */
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if (s->checkfn != Z_NULL)
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z->adler = s->check = (*s->checkfn)(s->check, q, n);
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/* copy */
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zmemcpy(p, q, n);
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p += n;
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q += n;
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}
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/* update pointers */
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z->next_out = p;
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s->read = q;
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/* done */
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return r;
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}
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