154 lines
3.7 KiB
Java
154 lines
3.7 KiB
Java
/* InflaterInputStream.java - Input stream filter for decompressing
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Copyright (C) 1999, 2000 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA.
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As a special exception, if you link this library with other files to
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produce an executable, this library does not by itself cause the
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resulting executable to be covered by the GNU General Public License.
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This exception does not however invalidate any other reasons why the
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executable file might be covered by the GNU General Public License. */
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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 InflaterInputStream extends FilterInputStream
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{
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protected void fill () throws IOException
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{
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len = in.read(buf, 0, buf.length);
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if (len != -1)
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inf.setInput(buf, 0, len);
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}
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public InflaterInputStream (InputStream in)
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{
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this (in, new Inflater (), 512);
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}
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public InflaterInputStream (InputStream in, Inflater infl)
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{
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this (in, infl, 512);
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}
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public InflaterInputStream (InputStream in, Inflater infl, int bufsize)
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{
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super (in);
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this.inf = infl;
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this.buf = new byte[bufsize];
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}
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public int read () throws IOException
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{
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byte[] buf = new byte[1];
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int r = read (buf, 0, 1);
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if (r != -1)
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r = buf[0] & 0xff;
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return r;
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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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if (inf == null)
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throw new IOException ("stream closed");
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if (inf.finished())
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return -1;
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if (inf.needsInput())
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fill ();
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int count;
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try
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{
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count = inf.inflate(buf, off, len);
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if (count == 0)
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{
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if (this.len == -1)
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return -1; // Couldn't get any more data to feed to the Inflater
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if (inf.needsDictionary())
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throw new ZipException ("Inflater needs Dictionary");
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}
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}
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catch (DataFormatException dfe)
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{
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throw new ZipException (dfe.getMessage());
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}
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return count;
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}
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public void close () throws IOException
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{
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inf = null;
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super.close ();
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}
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public int available () throws IOException
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{
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// According to the JDK 1.2 docs, this should only ever return 0
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// or 1 and should not be relied upon by Java programs.
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if (inf == null)
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throw new IOException ("stream closed");
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return inf.finished () ? 0 : 1;
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}
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public long skip (long n) throws IOException
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{
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if (inf == null)
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throw new IOException ("stream closed");
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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 = 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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}
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return s;
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}
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// Buffer for delivering uncompressed data to inflater.
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protected byte[] buf;
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// Inflater used to decompress data.
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protected Inflater inf;
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// Number of read bytes in buf.
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protected int len;
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}
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