/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.core.util;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CoderResult;
import org.teiid.core.types.DataTypeManager;
/**
* Replacement for the standard {@link java.io.InputStreamReader},
* which suffers from a <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4744247">bug</a> in sun.nio.cs.StreamDecoder
*/
public class InputStreamReader extends Reader {
private CharsetDecoder cd;
private ReadableByteChannel rbc;
private ByteBuffer bb;
private CharBuffer cb;
private boolean done;
public InputStreamReader(InputStream in, CharsetDecoder cd) {
this(in, cd, DataTypeManager.MAX_LOB_MEMORY_BYTES);
}
public InputStreamReader(InputStream in, CharsetDecoder cd, int bufferSize) {
this.cd = cd;
this.rbc = Channels.newChannel(in);
this.bb = ByteBuffer.allocate(bufferSize);
this.cb = CharBuffer.allocate((int)(bufferSize * (double)cd.maxCharsPerByte()));
this.cb.limit(0);
}
@Override
public void close() throws IOException {
rbc.close();
cd.reset();
}
@Override
public int read(char[] cbuf, int off, int len) throws IOException {
if ((off < 0) || (off > cbuf.length) || (len < 0) ||
((off + len) > cbuf.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return 0;
}
while (!done && !cb.hasRemaining()) {
int read = 0;
while ((read = rbc.read(bb)) == 0) {
//blocking read
}
bb.flip();
cb.clear();
CoderResult cr = cd.decode(bb, cb, read == -1);
if (!cr.isUnderflow()) {
cr.throwException();
}
if (read == -1) {
cr = cd.flush(cb);
if (!cr.isUnderflow()) {
cr.throwException();
}
done = true;
}
if (bb.position() != read) {
bb.compact();
} else {
bb.clear();
}
cb.flip();
}
len = Math.min(len, cb.remaining());
if (len == 0 && done) {
return -1;
}
cb.get(cbuf, off, len);
return len;
}
}