/*
* 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.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
import org.teiid.runtime.client.Messages;
/**
* Implements a buffered {@link InputStream} for a given {@link Reader} and {@link Charset}
*/
public class ReaderInputStream extends InputStream {
//even though we're dealing with chars, we'll use the same default
static final int DEFAULT_BUFFER_SIZE = 1<<13;
private final Reader reader;
private CharBuffer cb;
private ByteBuffer bb;
private boolean done;
private boolean wasOverflow;
private CharsetEncoder encoder;
private byte[] singleByte = new byte[1];
/**
* Creates a new inputstream that will replace any malformed/unmappable input
* @param reader
* @param charset
*/
public ReaderInputStream(Reader reader, Charset charset) {
this(reader, charset.newEncoder()
.onMalformedInput(CodingErrorAction.REPLACE)
.onUnmappableCharacter(CodingErrorAction.REPLACE),
DEFAULT_BUFFER_SIZE);
}
public ReaderInputStream(Reader reader, CharsetEncoder encoder) {
this(reader, encoder, DEFAULT_BUFFER_SIZE);
}
public ReaderInputStream(Reader reader, CharsetEncoder encoder, int bufferSize) {
this.reader = reader;
this.encoder = encoder;
this.encoder.reset();
this.cb = CharBuffer.allocate(bufferSize);
this.bb = ByteBuffer.allocate(bufferSize);
this.bb.limit(0);
}
@Override
public int read(byte[] bbuf, int off, int len) throws IOException {
if ((off < 0) || (off > bbuf.length) || (len < 0) ||
((off + len) > bbuf.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return 0;
}
while (!done && !bb.hasRemaining()) {
int read = 0;
int pos = cb.position();
if (!wasOverflow) {
while ((read = reader.read(cb)) == 0) {
//blocking read
}
cb.flip();
}
bb.clear();
CoderResult cr = encoder.encode(cb, bb, read == -1);
checkResult(cr);
if (read == -1 && !wasOverflow) {
cr = encoder.flush(bb);
checkResult(cr);
if (!wasOverflow) {
done = true;
}
}
if (!wasOverflow) {
if (read != 0 && cb.position() != read + pos) {
cb.compact();
} else {
cb.clear();
}
}
bb.flip();
}
len = Math.min(len, bb.remaining());
if (len == 0 && done) {
return -1;
}
bb.get(bbuf, off, len);
return len;
}
private void checkResult(CoderResult cr) throws IOException {
if (cr.isOverflow()) {
wasOverflow = true;
assert bb.position() > 0;
} else if (!cr.isUnderflow()) {
try {
cr.throwException();
} catch (CharacterCodingException e) {
throw new IOException(Messages.gs(Messages.TEIID.TEIID10083, encoder.charset().displayName()), e);
}
} else {
wasOverflow = false;
}
}
@Override
public int read() throws IOException {
int read = read(singleByte, 0, 1);
if (read == 1) {
return singleByte[0] & 0xff;
}
assert read != 0;
return -1;
}
@Override
public void close() throws IOException {
this.reader.close();
}
}