infutil.c
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上传日期:2007-06-13
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文件大小:2k
- /*
- * ===========================================================================
- * PRODUCTION $Log: infutil.c,v $
- * PRODUCTION Revision 1000.0 2003/10/29 15:49:55 gouriano
- * PRODUCTION PRODUCTION: IMPORTED [ORIGINAL] Dev-tree R1.1
- * PRODUCTION
- * ===========================================================================
- */
- /* inflate_util.c -- data and routines common to blocks and codes
- * Copyright (C) 1995-2002 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
- #include "zutil.h"
- #include "infblock.h"
- #include "inftrees.h"
- #include "infcodes.h"
- #include "infutil.h"
- struct inflate_codes_state {int dummy;}; /* for buggy compilers */
- /* And'ing with mask[n] masks the lower n bits */
- uInt inflate_mask[17] = {
- 0x0000,
- 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
- 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
- };
- /* copy as much as possible from the sliding window to the output area */
- int inflate_flush(s, z, r)
- inflate_blocks_statef *s;
- z_streamp z;
- int r;
- {
- uInt n;
- Bytef *p;
- Bytef *q;
- /* local copies of source and destination pointers */
- p = z->next_out;
- q = s->read;
- /* compute number of bytes to copy as far as end of window */
- n = (uInt)((q <= s->write ? s->write : s->end) - q);
- if (n > z->avail_out) n = z->avail_out;
- if (n && r == Z_BUF_ERROR) r = Z_OK;
- /* update counters */
- z->avail_out -= n;
- z->total_out += n;
- /* update check information */
- if (s->checkfn != Z_NULL)
- z->adler = s->check = (*s->checkfn)(s->check, q, n);
- /* copy as far as end of window */
- zmemcpy(p, q, n);
- p += n;
- q += n;
- /* see if more to copy at beginning of window */
- if (q == s->end)
- {
- /* wrap pointers */
- q = s->window;
- if (s->write == s->end)
- s->write = s->window;
- /* compute bytes to copy */
- n = (uInt)(s->write - q);
- if (n > z->avail_out) n = z->avail_out;
- if (n && r == Z_BUF_ERROR) r = Z_OK;
- /* update counters */
- z->avail_out -= n;
- z->total_out += n;
- /* update check information */
- if (s->checkfn != Z_NULL)
- z->adler = s->check = (*s->checkfn)(s->check, q, n);
- /* copy */
- zmemcpy(p, q, n);
- p += n;
- q += n;
- }
- /* update pointers */
- z->next_out = p;
- s->read = q;
- /* done */
- return r;
- }