/**
* 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.store.amq.reader;
import java.io.File;
import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import javax.jms.InvalidSelectorException;
import javax.jms.Message;
import org.apache.activemq.command.DataStructure;
import org.apache.activemq.filter.BooleanExpression;
import org.apache.activemq.kaha.impl.async.AsyncDataManager;
import org.apache.activemq.kaha.impl.async.Location;
import org.apache.activemq.openwire.OpenWireFormat;
import org.apache.activemq.selector.SelectorParser;
import org.apache.activemq.util.ByteSequence;
import org.apache.activemq.wireformat.WireFormat;
/**
* Reads and iterates through data log files for the AMQMessage Store
*
*/
public class AMQReader implements Iterable<Message> {
private AsyncDataManager dataManager;
private WireFormat wireFormat = new OpenWireFormat();
private File file;
private BooleanExpression expression;
/**
* List all the data files in a directory
* @param directory
* @return
* @throws IOException
*/
public static Set<File> listDataFiles(File directory) throws IOException{
Set<File>result = new HashSet<File>();
if (directory == null || !directory.exists() || !directory.isDirectory()) {
throw new IOException("Invalid Directory " + directory);
}
AsyncDataManager dataManager = new AsyncDataManager();
dataManager.setDirectory(directory);
dataManager.start();
Set<File> set = dataManager.getFiles();
if (set != null) {
result.addAll(set);
}
dataManager.close();
return result;
}
/**
* Create the AMQReader to read a directory of amq data logs - or an
* individual data log file
*
* @param file the directory - or file
* @throws IOException
* @throws InvalidSelectorException
* @throws IOException
* @throws InvalidSelectorException
*/
public AMQReader(File file) throws InvalidSelectorException, IOException {
this(file,null);
}
/**
* Create the AMQReader to read a directory of amq data logs - or an
* individual data log file
*
* @param file the directory - or file
* @param selector the JMS selector or null to select all
* @throws IOException
* @throws InvalidSelectorException
*/
public AMQReader(File file, String selector) throws IOException, InvalidSelectorException {
String str = selector != null ? selector.trim() : null;
if (str != null && str.length() > 0) {
this.expression=SelectorParser.parse(str);
}
dataManager = new AsyncDataManager();
dataManager.setArchiveDataLogs(false);
if (file.isDirectory()) {
dataManager.setDirectory(file);
} else {
dataManager.setDirectory(file.getParentFile());
dataManager.setDirectoryArchive(file);
this.file = file;
}
dataManager.start();
}
public Iterator<Message> iterator() {
return new AMQIterator(this,this.expression);
}
protected MessageLocation getNextMessage(MessageLocation lastLocation)
throws IllegalStateException, IOException {
if (this.file != null) {
return getInternalNextMessage(this.file, lastLocation);
}
return getInternalNextMessage(lastLocation);
}
private MessageLocation getInternalNextMessage(MessageLocation lastLocation)
throws IllegalStateException, IOException {
return getInternalNextMessage(null, lastLocation);
}
private MessageLocation getInternalNextMessage(File file,
MessageLocation lastLocation) throws IllegalStateException,
IOException {
MessageLocation result = lastLocation;
if (result != null) {
result.setMessage(null);
}
Message message = null;
Location pos = lastLocation != null ? lastLocation.getLocation() : null;
while ((pos = getNextLocation(file, pos)) != null) {
message = getMessage(pos);
if (message != null) {
if (result == null) {
result = new MessageLocation();
}
result.setMessage(message);
break;
}
}
result.setLocation(pos);
if (pos == null && message == null) {
result = null;
} else {
result.setLocation(pos);
}
return result;
}
private Location getNextLocation(File file, Location last)
throws IllegalStateException, IOException {
if (file != null) {
return dataManager.getNextLocation(file, last, true);
}
return dataManager.getNextLocation(last);
}
private Message getMessage(Location location) throws IOException {
ByteSequence data = dataManager.read(location);
DataStructure c = (DataStructure) wireFormat.unmarshal(data);
if (c instanceof Message) {
return (Message) c;
}
return null;
}
}