/* 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;

}

