/* inflate_util.c -- data and routines common to blocks and codes
 * Copyright (C) 1995-1998 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(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;
}
