+++ /dev/null
-/* CRC32.java - Computes CRC32 data checksum of a data stream
- Copyright (C) 1999. 2000, 2001 Free Software Foundation, Inc.
-
-This file is part of GNU Classpath.
-
-GNU Classpath is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
-
-GNU Classpath is distributed in the hope that it will be useful, but
-WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GNU Classpath; see the file COPYING. If not, write to the
-Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-02111-1307 USA.
-
-Linking this library statically or dynamically with other modules is
-making a combined work based on this library. Thus, the terms and
-conditions of the GNU General Public License cover the whole
-combination.
-
-As a special exception, the copyright holders of this library give you
-permission to link this library with independent modules to produce an
-executable, regardless of the license terms of these independent
-modules, and to copy and distribute the resulting executable under
-terms of your choice, provided that you also meet, for each linked
-independent module, the terms and conditions of the license of that
-module. An independent module is a module which is not derived from
-or based on this library. If you modify this library, you may extend
-this exception to your version of the library, but you are not
-obligated to do so. If you do not wish to do so, delete this
-exception statement from your version. */
-
-package java.util.zip;
-
-/*
- * Written using on-line Java Platform 1.2 API Specification, as well
- * as "The Java Class Libraries", 2nd edition (Addison-Wesley, 1998).
- * The actual CRC32 algorithm is taken from RFC 1952.
- * Status: Believed complete and correct.
- */
-
-/**
- * Computes CRC32 data checksum of a data stream.
- * The actual CRC32 algorithm is described in RFC 1952
- * (GZIP file format specification version 4.3).
- * Can be used to get the CRC32 over a stream if used with checked input/output
- * streams.
- *
- * @see InflaterInputStream
- * @see DeflaterOutputStream
- *
- * @author Per Bothner
- * @date April 1, 1999.
- */
-public class CRC32 implements Checksum
-{
- /** The crc data checksum so far. */
- private int crc = 0;
-
- /** The fast CRC table. Computed once when the CRC32 class is loaded. */
- private static int[] crc_table = make_crc_table();
-
- /** Make the table for a fast CRC. */
- private static int[] make_crc_table ()
- {
- int[] crc_table = new int[256];
- for (int n = 0; n < 256; n++)
- {
- int c = n;
- for (int k = 8; --k >= 0; )
- {
- if ((c & 1) != 0)
- c = 0xedb88320 ^ (c >>> 1);
- else
- c = c >>> 1;
- }
- crc_table[n] = c;
- }
- return crc_table;
- }
-
- /**
- * Returns the CRC32 data checksum computed so far.
- */
- public long getValue ()
- {
- return (long) crc & 0xffffffffL;
- }
-
- /**
- * Resets the CRC32 data checksum as if no update was ever called.
- */
- public void reset () { crc = 0; }
-
- /**
- * Updates the checksum with the int bval.
- *
- * @param bval (the byte is taken as the lower 8 bits of bval)
- */
-
- public void update (int bval)
- {
- int c = ~crc;
- c = crc_table[(c ^ bval) & 0xff] ^ (c >>> 8);
- crc = ~c;
- }
-
- /**
- * Adds the byte array to the data checksum.
- *
- * @param buf the buffer which contains the data
- * @param off the offset in the buffer where the data starts
- * @param len the length of the data
- */
- public void update (byte[] buf, int off, int len)
- {
- int c = ~crc;
- while (--len >= 0)
- c = crc_table[(c ^ buf[off++]) & 0xff] ^ (c >>> 8);
- crc = ~c;
- }
-
- /**
- * Adds the complete byte array to the data checksum.
- */
- public void update (byte[] buf) { update(buf, 0, buf.length); }
-}
projects / msp430-gcc.git / blobdiff