ActiveMQ example source code file (IndexItem.java)

This example ActiveMQ source code file (IndexItem.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

badmagicexception, dataitem, dataitem, index_size, indexes_only_size, indexitem, indexitem, io, ioexception, ioexception, magic, position_not_set, position_not_set, storelocation, string

The ActiveMQ IndexItem.java source code

/**
 * 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.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.activemq.kaha.StoreEntry;
import org.apache.activemq.kaha.StoreLocation;
import org.apache.activemq.kaha.impl.data.DataItem;
import org.apache.activemq.kaha.impl.data.Item;

/**
 * A an Item with a relative position and location to other Items in the Store
 * 
 * 
 */
public class IndexItem implements Item, StoreEntry {

    public static final int INDEX_SIZE = 51;
    public static final int INDEXES_ONLY_SIZE = 19;

    protected long offset = POSITION_NOT_SET;

    // used by linked list
    IndexItem next;
    IndexItem prev;

    private long previousItem = POSITION_NOT_SET;
    private long nextItem = POSITION_NOT_SET;
    private boolean active = true;

    // TODO: consider just using a DataItem for the following fields.
    private long keyOffset = POSITION_NOT_SET;
    private int keyFile = (int)POSITION_NOT_SET;
    private int keySize;

    private long valueOffset = POSITION_NOT_SET;
    private int valueFile = (int)POSITION_NOT_SET;
    private int valueSize;

    /**
     * Default Constructor
     */
    public IndexItem() {
    }

    void reset() {
        previousItem = POSITION_NOT_SET;
        nextItem = POSITION_NOT_SET;
        keyOffset = POSITION_NOT_SET;
        keyFile = (int)POSITION_NOT_SET;
        keySize = 0;
        valueOffset = POSITION_NOT_SET;
        valueFile = (int)POSITION_NOT_SET;
        valueSize = 0;
        active = true;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getKeyDataItem()
     */
    public StoreLocation getKeyDataItem() {
        DataItem result = new DataItem();
        result.setOffset(keyOffset);
        result.setFile(keyFile);
        result.setSize(keySize);
        return result;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getValueDataItem()
     */
    public StoreLocation getValueDataItem() {
        DataItem result = new DataItem();
        result.setOffset(valueOffset);
        result.setFile(valueFile);
        result.setSize(valueSize);
        return result;
    }

    public void setValueData(StoreLocation item) {
        valueOffset = item.getOffset();
        valueFile = item.getFile();
        valueSize = item.getSize();
    }

    public void setKeyData(StoreLocation item) {
        keyOffset = item.getOffset();
        keyFile = item.getFile();
        keySize = item.getSize();
    }

    /**
     * @param dataOut
     * @throws IOException
     */
    public void write(DataOutput dataOut) throws IOException {
        dataOut.writeShort(MAGIC);
        dataOut.writeBoolean(active);
        dataOut.writeLong(previousItem);
        dataOut.writeLong(nextItem);
        dataOut.writeInt(keyFile);
        dataOut.writeLong(keyOffset);
        dataOut.writeInt(keySize);
        dataOut.writeInt(valueFile);
        dataOut.writeLong(valueOffset);
        dataOut.writeInt(valueSize);
    }

    void updateIndexes(DataOutput dataOut) throws IOException {
        dataOut.writeShort(MAGIC);
        dataOut.writeBoolean(active);
        dataOut.writeLong(previousItem);
        dataOut.writeLong(nextItem);
    }

    /**
     * @param dataIn
     * @throws IOException
     */
    public void read(DataInput dataIn) throws IOException {
        if (dataIn.readShort() != MAGIC) {
            throw new BadMagicException();
        }
        active = dataIn.readBoolean();
        previousItem = dataIn.readLong();
        nextItem = dataIn.readLong();
        keyFile = dataIn.readInt();
        keyOffset = dataIn.readLong();
        keySize = dataIn.readInt();
        valueFile = dataIn.readInt();
        valueOffset = dataIn.readLong();
        valueSize = dataIn.readInt();
    }

    void readIndexes(DataInput dataIn) throws IOException {
        if (dataIn.readShort() != MAGIC) {
            throw new BadMagicException();
        }
        active = dataIn.readBoolean();
        previousItem = dataIn.readLong();
        nextItem = dataIn.readLong();
    }

    /**
     * @param newPrevEntry
     */
    public void setPreviousItem(long newPrevEntry) {
        previousItem = newPrevEntry;
    }

    /**
     * @return prev item
     */
    long getPreviousItem() {
        return previousItem;
    }

    /**
     * @param newNextEntry
     */
    public void setNextItem(long newNextEntry) {
        nextItem = newNextEntry;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getNextItem()
     */
    public long getNextItem() {
        return nextItem;
    }

    /**
     * @param newObjectOffset
     */
    void setKeyOffset(long newObjectOffset) {
        keyOffset = newObjectOffset;
    }

    /**
     * @return key offset
     */
    long getKeyOffset() {
        return keyOffset;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getKeyFile()
     */
    public int getKeyFile() {
        return keyFile;
    }

    /**
     * @param keyFile The keyFile to set.
     */
    void setKeyFile(int keyFile) {
        this.keyFile = keyFile;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getValueFile()
     */
    public int getValueFile() {
        return valueFile;
    }

    /**
     * @param valueFile The valueFile to set.
     */
    void setValueFile(int valueFile) {
        this.valueFile = valueFile;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getValueOffset()
     */
    public long getValueOffset() {
        return valueOffset;
    }

    /**
     * @param valueOffset The valueOffset to set.
     */
    public void setValueOffset(long valueOffset) {
        this.valueOffset = valueOffset;
    }

    /**
     * @return Returns the active.
     */
    boolean isActive() {
        return active;
    }

    /**
     * @param active The active to set.
     */
    void setActive(boolean active) {
        this.active = active;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getOffset()
     */
    public long getOffset() {
        return offset;
    }

    /**
     * @param offset The offset to set.
     */
    public void setOffset(long offset) {
        this.offset = offset;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getKeySize()
     */
    public int getKeySize() {
        return keySize;
    }

    public void setKeySize(int keySize) {
        this.keySize = keySize;
    }

    /**
     * @return
     * @see org.apache.activemq.kaha.StoreEntry#getValueSize()
     */
    public int getValueSize() {
        return valueSize;
    }

    public void setValueSize(int valueSize) {
        this.valueSize = valueSize;
    }
    
    void copyIndex(IndexItem other) {
        this.offset=other.offset;
        this.active=other.active;
        this.previousItem=other.previousItem;
        this.nextItem=other.nextItem;
    }

    /**
     * @return print of 'this'
     */
    public String toString() {
        String result = "offset=" + offset + ", key=(" + keyFile + ", " + keyOffset + ", " + keySize + ")" + ", value=(" + valueFile + ", " + valueOffset + ", " + valueSize + ")"
                        + ", previousItem=" + previousItem + ", nextItem=" + nextItem;
        return result;
    }

    public boolean equals(Object obj) {
        boolean result = obj == this;
        if (!result && obj != null && obj instanceof IndexItem) {
            IndexItem other = (IndexItem)obj;
            result = other.offset == this.offset;
        }
        return result;
    }

    public int hashCode() {
        return (int)offset;
    }
}