169 lines
3.9 KiB
Java
169 lines
3.9 KiB
Java
/* Copyright (C) 1998, 1999, 2001 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.io;
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import gnu.gcj.convert.*;
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/**
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* @author Per Bothner <bothner@cygnus.com>
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* @date April 22, 1998.
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*/
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/* Written using "Java Class Libraries", 2nd edition, plus online
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* API docs for JDK 1.2 beta from http://www.javasoft.com.
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* Status: Believed complete and correct, but only supports 8859_1.
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*/
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public class InputStreamReader extends Reader
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{
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BufferedInputStream in;
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// Buffer of chars read from in and converted but not consumed.
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char[] work;
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// Next available character (in work buffer) to read.
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int wpos;
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// Last available character (in work buffer) to read.
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int wcount;
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BytesToUnicode converter;
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public InputStreamReader(InputStream in)
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{
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this(in, BytesToUnicode.getDefaultDecoder());
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}
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public InputStreamReader(InputStream in, String enc)
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throws UnsupportedEncodingException
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{
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this(in, BytesToUnicode.getDecoder(enc));
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}
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private InputStreamReader(InputStream in, BytesToUnicode decoder)
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{
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// FIXME: someone could pass in a BufferedInputStream whose buffer
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// is smaller than the longest encoded character for this
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// encoding. We will probably go into an infinite loop in this
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// case. We probably ought to just have our own byte buffering
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// here.
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this.in = in instanceof BufferedInputStream
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? (BufferedInputStream) in
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: new BufferedInputStream(in);
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/* Don't need to call super(in) here as long as the lock gets set. */
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this.lock = in;
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converter = decoder;
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converter.setInput(this.in.buf, 0, 0);
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}
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public void close() throws IOException
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{
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synchronized (lock)
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{
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if (in != null)
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in.close();
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in = null;
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work = null;
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wpos = wcount = 0;
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}
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}
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public String getEncoding() { return converter.getName(); }
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public boolean ready() throws IOException
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{
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synchronized (lock)
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{
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if (in == null)
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throw new IOException("Stream closed");
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if (wpos < wcount)
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return true;
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// According to the spec, an InputStreamReader is ready if its
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// input buffer is not empty (above), or if bytes are
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// available on the underlying byte stream.
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return in.available () > 0;
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}
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}
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public int read(char buf[], int offset, int length) throws IOException
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{
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synchronized (lock)
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{
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if (in == null)
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throw new IOException("Stream closed");
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if (length == 0)
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return 0;
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int wavail = wcount - wpos;
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if (wavail <= 0)
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{
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// Nothing waiting, so refill our buffer.
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if (! refill ())
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return -1;
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wavail = wcount - wpos;
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}
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if (length > wavail)
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length = wavail;
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System.arraycopy(work, wpos, buf, offset, length);
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wpos += length;
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return length;
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}
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}
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public int read() throws IOException
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{
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synchronized (lock)
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{
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if (in == null)
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throw new IOException("Stream closed");
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int wavail = wcount - wpos;
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if (wavail <= 0)
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{
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// Nothing waiting, so refill our buffer.
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if (! refill ())
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return -1;
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}
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return work[wpos++];
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}
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}
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// Read more bytes and convert them into the WORK buffer.
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// Return false on EOF.
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private boolean refill () throws IOException
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{
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wcount = wpos = 0;
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if (work == null)
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work = new char[100];
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for (;;)
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{
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// We have knowledge of the internals of BufferedInputStream
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// here. Eww.
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in.mark (0);
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// BufferedInputStream.refill() can only be called when
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// `pos>=count'.
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boolean r = in.pos < in.count || in.refill ();
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in.reset ();
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if (! r)
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return false;
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converter.setInput(in.buf, in.pos, in.count);
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int count = converter.read (work, wpos, work.length - wpos);
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in.skip(converter.inpos - in.pos);
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if (count > 0)
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{
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wcount += count;
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return true;
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}
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}
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}
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}
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