text: /* inflate_util.c -- data and routines common to blocks and codes
   * Copyright (C) 1995-1996 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;
  }
  