forsyth20121205-174063a80cc13 years agoHistory
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/* 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 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;}