ref: ad18b367e9c658d94cf85224ba46c11f092ff7fd
dir: /src/gzip/infutil.c/
/* 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"
/* And'ing with mask[n] masks the lower n bits */
local const 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 */
local 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;
}