trunk/activemq-core/src/main/java/org/apache/activemq/kaha/impl/index/StoreIndexWriter.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.activemq.kaha.impl.index;

import java.io.IOException;
import java.io.RandomAccessFile;

import org.apache.activemq.kaha.impl.DataManager;
import org.apache.activemq.util.DataByteArrayOutputStream;

/**
 * Optimized Store writer
 * 
 * 
 */
class StoreIndexWriter {

    protected final DataByteArrayOutputStream dataOut = new DataByteArrayOutputStream();
    protected final RandomAccessFile file;
    protected final String name;
    protected final DataManager redoLog;

    /**
     * Construct a Store index writer
     * 
     * @param file
     */
    StoreIndexWriter(RandomAccessFile file) {
        this(file, null, null);
    }

    public StoreIndexWriter(RandomAccessFile file, String indexName, DataManager redoLog) {
        this.file = file;
        this.name = indexName;
        this.redoLog = redoLog;
    }

    void storeItem(IndexItem indexItem) throws IOException {

        if (redoLog != null) {
            RedoStoreIndexItem redo = new RedoStoreIndexItem(name, indexItem.getOffset(), indexItem);
            redoLog.storeRedoItem(redo);
        }

        dataOut.reset();
        indexItem.write(dataOut);
        file.seek(indexItem.getOffset());
        file.write(dataOut.getData(), 0, IndexItem.INDEX_SIZE);
    }

    void updateIndexes(IndexItem indexItem) throws IOException {
        if (redoLog != null) {
            RedoStoreIndexItem redo = new RedoStoreIndexItem(name, indexItem.getOffset(), indexItem);
            redoLog.storeRedoItem(redo);
        }

        dataOut.reset();
        indexItem.updateIndexes(dataOut);
        file.seek(indexItem.getOffset());
        file.write(dataOut.getData(), 0, IndexItem.INDEXES_ONLY_SIZE);
    }

    public void redoStoreItem(RedoStoreIndexItem redo) throws IOException {
        dataOut.reset();
        redo.getIndexItem().write(dataOut);
        file.seek(redo.getOffset());
        file.write(dataOut.getData(), 0, IndexItem.INDEX_SIZE);
    }

}