82 lines
1.5 KiB
Java
82 lines
1.5 KiB
Java
// CheckedInputStream.java - Compute checksum of data being read.
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/* Copyright (C) 1999 Free Software Foundation
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This file is part of libgcj.
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This software is copyrighted work licensed under the terms of the
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Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
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details. */
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package java.util.zip;
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import java.io.FilterInputStream;
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import java.io.InputStream;
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import java.io.IOException;
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/**
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* @author Tom Tromey
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* @date May 17, 1999
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*/
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/* Written using on-line Java Platform 1.2 API Specification
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* and JCL book.
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* Believed complete and correct.
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*/
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public class CheckedInputStream extends FilterInputStream
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{
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public CheckedInputStream (InputStream in, Checksum sum)
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{
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super (in);
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this.sum = sum;
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}
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public Checksum getChecksum ()
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{
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return sum;
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}
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public int read () throws IOException
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{
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int x = in.read();
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if (x != -1)
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sum.update(x);
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return x;
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}
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public int read (byte[] buf, int off, int len) throws IOException
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{
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int r = in.read(buf, off, len);
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if (r != -1)
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sum.update(buf, off, r);
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return r;
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}
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public long skip (long n) throws IOException
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{
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if (n == 0)
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return 0;
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int min = (int) Math.min(n, 1024);
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byte[] buf = new byte[min];
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long s = 0;
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while (n > 0)
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{
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int r = in.read(buf, 0, min);
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if (r == -1)
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break;
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n -= r;
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s += r;
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min = (int) Math.min(n, 1024);
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sum.update(buf, 0, r);
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}
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return s;
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}
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// The checksum object.
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private Checksum sum;
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}
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