/*
* Copyright 2004-2009 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.compass.needle.terracotta;
import java.io.IOException;
import org.apache.lucene.store.IndexOutput;
/**
* A terracotta index output that only adds the file when the output is closed.
*
* @author kimchy
*/
public class FlushOnCloseTerracottaIndexOutput extends IndexOutput {
private final TerracottaDirectory dir;
private final int bufferSize;
private final String name;
private TerracottaFile file;
private byte[] currentBuffer;
private int currentBufferIndex;
private int bufferPosition;
private long bufferStart;
private int bufferLength;
private boolean open;
FlushOnCloseTerracottaIndexOutput(TerracottaDirectory dir, String name) throws IOException {
this.dir = dir;
this.name = name;
this.bufferSize = dir.getBufferSize();
file = new TerracottaFile();
// just add an empty file to mark the fact we created a file for this name
dir.addFile(name, TerracottaDirectory.EMPTY_FILE);
open = true;
// make sure that we switch to the
// first needed buffer lazily
currentBufferIndex = -1;
currentBuffer = null;
}
public void writeByte(byte b) throws IOException {
if (bufferPosition == bufferLength) {
currentBufferIndex++;
switchCurrentBuffer();
}
currentBuffer[bufferPosition++] = b;
}
public void writeBytes(byte[] b, int offset, int len) throws IOException {
while (len > 0) {
if (bufferPosition == bufferLength) {
currentBufferIndex++;
switchCurrentBuffer();
}
int remainInBuffer = currentBuffer.length - bufferPosition;
int bytesToCopy = len < remainInBuffer ? len : remainInBuffer;
System.arraycopy(b, offset, currentBuffer, bufferPosition, bytesToCopy);
offset += bytesToCopy;
len -= bytesToCopy;
bufferPosition += bytesToCopy;
}
}
public long getFilePointer() {
return currentBufferIndex < 0 ? 0 : bufferStart + bufferPosition;
}
public void flush() throws IOException {
setFileLength();
}
public void close() throws IOException {
if (!open) {
return;
}
open = false;
// flush any buffer we might have
flush();
file.setLastModified(System.currentTimeMillis());
dir.addFile(name, file);
currentBuffer = null;
}
public long length() {
return file.getLength();
}
public void seek(long pos) throws IOException {
// set the file length in case we seek back
// and flush() has not been called yet
setFileLength();
if (pos < bufferStart || pos >= bufferStart + bufferLength) {
currentBufferIndex = (int) (pos / bufferSize);
switchCurrentBuffer();
}
bufferPosition = (int) (pos % bufferSize);
}
private void switchCurrentBuffer() throws IOException {
if (currentBufferIndex == file.getNumBuffers()) {
currentBuffer = file.addBuffer(bufferSize);
} else {
currentBuffer = file.getBuffer(currentBufferIndex);
}
bufferPosition = 0;
bufferStart = (long) bufferSize * (long) currentBufferIndex;
bufferLength = currentBuffer.length;
}
private void setFileLength() {
long pointer = bufferStart + bufferPosition;
if (pointer > file.length) {
file.setLength(pointer);
}
}
}