zlib.c

	/* get extra bits for length */
	e &= 15;
	c = t->base + ((uInt)b & inflate_mask[e]);
	DUMPBITS(e)
	Tracevv((stderr, "inflate:         * length %u\n", c));

	/* decode distance base of block to copy */
	GRABBITS(15);           /* max bits for distance code */
	e = (t = td + ((uInt)b & md))->exop;
	do {
	  DUMPBITS(t->bits)
	  if (e & 16)
	  {
	    /* get extra bits to add to distance base */
	    e &= 15;
	    GRABBITS(e)         /* get extra bits (up to 13) */
	    d = t->base + ((uInt)b & inflate_mask[e]);
	    DUMPBITS(e)
	    Tracevv((stderr, "inflate:         * distance %u\n", d));

	    /* do the copy */
	    m -= c;
	    if ((uInt)(q - s->window) >= d)     /* offset before dest */
	    {                                   /*  just copy */
	      r = q - d;
	      *q++ = *r++;  c--;        /* minimum count is three, */
	      *q++ = *r++;  c--;        /*  so unroll loop a little */
	    }
	    else                        /* else offset after destination */
	    {
	      e = d - (q - s->window);  /* bytes from offset to end */
	      r = s->end - e;           /* pointer to offset */
	      if (c > e)                /* if source crosses, */
	      {
		c -= e;                 /* copy to end of window */
		do {
		  *q++ = *r++;
		} while (--e);
		r = s->window;          /* copy rest from start of window */
	      }
	    }
	    do {                        /* copy all or what's left */
	      *q++ = *r++;
	    } while (--c);
	    break;
	  }
	  else if ((e & 64) == 0)
	    e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
	  else
	  {
	    z->msg = "invalid distance code";
	    UNGRAB
	    UPDATE
	    return Z_DATA_ERROR;
	  }
	} while (1);
	break;
      }
      if ((e & 64) == 0)
      {
	if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
	{
	  DUMPBITS(t->bits)
	  Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
		    "inflate:         * literal '%c'\n" :
		    "inflate:         * literal 0x%02x\n", t->base));
	  *q++ = (Byte)t->base;
	  m--;
	  break;
	}
      }
      else if (e & 32)
      {
	Tracevv((stderr, "inflate:         * end of block\n"));
	UNGRAB
	UPDATE
	return Z_STREAM_END;
      }
      else
      {
	z->msg = "invalid literal/length code";
	UNGRAB
	UPDATE
	return Z_DATA_ERROR;
      }
    } while (1);
  } while (m >= 258 && n >= 10);

  /* not enough input or output--restore pointers and return */
  UNGRAB
  UPDATE
  return Z_OK;
}


/*+++++*/
/* zutil.c -- target dependent utility functions for the compression library
 * Copyright (C) 1995 Jean-loup Gailly.
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */

char *zlib_version = ZLIB_VERSION;

char *z_errmsg[] = {
"stream end",          /* Z_STREAM_END    1 */
"",                    /* Z_OK            0 */
"file error",          /* Z_ERRNO        (-1) */
"stream error",        /* Z_STREAM_ERROR (-2) */
"data error",          /* Z_DATA_ERROR   (-3) */
"insufficient memory", /* Z_MEM_ERROR    (-4) */
"buffer error",        /* Z_BUF_ERROR    (-5) */
""};


/*+++++*/
/* adler32.c -- compute the Adler-32 checksum of a data stream
 * Copyright (C) 1995 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */

#define BASE 65521L /* largest prime smaller than 65536 */
#define NMAX 5552
/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */

#define DO1(buf)  {s1 += *buf++; s2 += s1;}
#define DO2(buf)  DO1(buf); DO1(buf);
#define DO4(buf)  DO2(buf); DO2(buf);
#define DO8(buf)  DO4(buf); DO4(buf);
#define DO16(buf) DO8(buf); DO8(buf);

/* ========================================================================= */
uLong adler32(adler, buf, len)
    uLong adler;
    Bytef *buf;
    uInt len;
{
    unsigned long s1 = adler & 0xffff;
    unsigned long s2 = (adler >> 16) & 0xffff;
    int k;

    if (buf == Z_NULL) return 1L;

    while (len > 0) {
	k = len < NMAX ? len : NMAX;
	len -= k;
	while (k >= 16) {
	    DO16(buf);
	    k -= 16;
	}
	if (k != 0) do {
	    DO1(buf);
	} while (--k);
	s1 %= BASE;
	s2 %= BASE;
    }
    return (s2 << 16) | s1;
}