/**
* 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.kahadb.scheduler;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.UUID;
import org.apache.activemq.store.kahadb.AbstractKahaDBMetaData;
import org.apache.activemq.store.kahadb.disk.index.BTreeIndex;
import org.apache.activemq.store.kahadb.disk.page.Transaction;
import org.apache.activemq.store.kahadb.disk.util.IntegerMarshaller;
import org.apache.activemq.store.kahadb.disk.util.LocationMarshaller;
import org.apache.activemq.store.kahadb.disk.util.StringMarshaller;
import org.apache.activemq.store.kahadb.disk.util.VariableMarshaller;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The KahaDB MetaData used to house the Index data for the KahaDB implementation
* of a JobSchedulerStore.
*/
public class JobSchedulerKahaDBMetaData extends AbstractKahaDBMetaData<JobSchedulerKahaDBMetaData> {
static final Logger LOG = LoggerFactory.getLogger(JobSchedulerKahaDBMetaData.class);
private final JobSchedulerStoreImpl store;
private UUID token = JobSchedulerStoreImpl.SCHEDULER_STORE_TOKEN;
private int version = JobSchedulerStoreImpl.CURRENT_VERSION;
private BTreeIndex<Integer, List<Integer>> removeLocationTracker;
private BTreeIndex<Integer, Integer> journalRC;
private BTreeIndex<String, JobSchedulerImpl> storedSchedulers;
/**
* Creates a new instance of this meta data object with the assigned
* parent JobSchedulerStore instance.
*
* @param store
* the store instance that owns this meta data.
*/
public JobSchedulerKahaDBMetaData(JobSchedulerStoreImpl store) {
this.store = store;
}
/**
* @return the current value of the Scheduler store identification token.
*/
public UUID getToken() {
return this.token;
}
/**
* @return the current value of the version tag for this meta data instance.
*/
public int getVersion() {
return this.version;
}
/**
* Gets the index that contains the location tracking information for Jobs
* that have been removed from the index but whose add operation has yet
* to be removed from the Journal.
*
* The Journal log file where a remove command is written cannot be released
* until the log file with the original add command has also been released,
* otherwise on a log replay the scheduled job could reappear in the scheduler
* since its corresponding remove might no longer be present.
*
* @return the remove command location tracker index.
*/
public BTreeIndex<Integer, List<Integer>> getRemoveLocationTracker() {
return this.removeLocationTracker;
}
/**
* Gets the index used to track the number of reference to a Journal log file.
*
* A log file in the Journal can only be considered for removal after all the
* references to it have been released.
*
* @return the journal log file reference counter index.
*/
public BTreeIndex<Integer, Integer> getJournalRC() {
return this.journalRC;
}
/**
* Gets the index of JobScheduler instances that have been created and stored
* in the JobSchedulerStore instance.
*
* @return the index of stored JobScheduler instances.
*/
public BTreeIndex<String, JobSchedulerImpl> getJobSchedulers() {
return this.storedSchedulers;
}
@Override
public void initialize(Transaction tx) throws IOException {
this.storedSchedulers = new BTreeIndex<String, JobSchedulerImpl>(store.getPageFile(), tx.allocate().getPageId());
this.journalRC = new BTreeIndex<Integer, Integer>(store.getPageFile(), tx.allocate().getPageId());
this.removeLocationTracker = new BTreeIndex<Integer, List<Integer>>(store.getPageFile(), tx.allocate().getPageId());
}
@Override
public void load(Transaction tx) throws IOException {
this.storedSchedulers.setKeyMarshaller(StringMarshaller.INSTANCE);
this.storedSchedulers.setValueMarshaller(new JobSchedulerMarshaller(this.store));
this.storedSchedulers.load(tx);
this.journalRC.setKeyMarshaller(IntegerMarshaller.INSTANCE);
this.journalRC.setValueMarshaller(IntegerMarshaller.INSTANCE);
this.journalRC.load(tx);
this.removeLocationTracker.setKeyMarshaller(IntegerMarshaller.INSTANCE);
this.removeLocationTracker.setValueMarshaller(new IntegerListMarshaller());
this.removeLocationTracker.load(tx);
}
/**
* Loads all the stored JobScheduler instances into the provided map.
*
* @param tx
* the Transaction under which the load operation should be executed.
* @param schedulers
* a Map<String, JobSchedulerImpl> into which the loaded schedulers are stored.
*
* @throws IOException if an error occurs while performing the load operation.
*/
public void loadScheduler(Transaction tx, Map<String, JobSchedulerImpl> schedulers) throws IOException {
for (Iterator<Entry<String, JobSchedulerImpl>> i = this.storedSchedulers.iterator(tx); i.hasNext();) {
Entry<String, JobSchedulerImpl> entry = i.next();
entry.getValue().load(tx);
schedulers.put(entry.getKey(), entry.getValue());
}
}
@Override
public void read(DataInput in) throws IOException {
try {
long msb = in.readLong();
long lsb = in.readLong();
this.token = new UUID(msb, lsb);
} catch (Exception e) {
throw new UnknownStoreVersionException(e);
}
if (!token.equals(JobSchedulerStoreImpl.SCHEDULER_STORE_TOKEN)) {
throw new UnknownStoreVersionException(token.toString());
}
this.version = in.readInt();
if (in.readBoolean()) {
setLastUpdateLocation(LocationMarshaller.INSTANCE.readPayload(in));
} else {
setLastUpdateLocation(null);
}
this.storedSchedulers = new BTreeIndex<String, JobSchedulerImpl>(store.getPageFile(), in.readLong());
this.storedSchedulers.setKeyMarshaller(StringMarshaller.INSTANCE);
this.storedSchedulers.setValueMarshaller(new JobSchedulerMarshaller(this.store));
this.journalRC = new BTreeIndex<Integer, Integer>(store.getPageFile(), in.readLong());
this.journalRC.setKeyMarshaller(IntegerMarshaller.INSTANCE);
this.journalRC.setValueMarshaller(IntegerMarshaller.INSTANCE);
this.removeLocationTracker = new BTreeIndex<Integer, List<Integer>>(store.getPageFile(), in.readLong());
this.removeLocationTracker.setKeyMarshaller(IntegerMarshaller.INSTANCE);
this.removeLocationTracker.setValueMarshaller(new IntegerListMarshaller());
LOG.info("Scheduler Store version {} loaded", this.version);
}
@Override
public void write(DataOutput out) throws IOException {
out.writeLong(this.token.getMostSignificantBits());
out.writeLong(this.token.getLeastSignificantBits());
out.writeInt(this.version);
if (getLastUpdateLocation() != null) {
out.writeBoolean(true);
LocationMarshaller.INSTANCE.writePayload(getLastUpdateLocation(), out);
} else {
out.writeBoolean(false);
}
out.writeLong(this.storedSchedulers.getPageId());
out.writeLong(this.journalRC.getPageId());
out.writeLong(this.removeLocationTracker.getPageId());
}
private class JobSchedulerMarshaller extends VariableMarshaller<JobSchedulerImpl> {
private final JobSchedulerStoreImpl store;
JobSchedulerMarshaller(JobSchedulerStoreImpl store) {
this.store = store;
}
@Override
public JobSchedulerImpl readPayload(DataInput dataIn) throws IOException {
JobSchedulerImpl result = new JobSchedulerImpl(this.store);
result.read(dataIn);
return result;
}
@Override
public void writePayload(JobSchedulerImpl js, DataOutput dataOut) throws IOException {
js.write(dataOut);
}
}
private class IntegerListMarshaller extends VariableMarshaller<List<Integer>> {
@Override
public List<Integer> readPayload(DataInput dataIn) throws IOException {
List<Integer> result = new ArrayList<Integer>();
int size = dataIn.readInt();
for (int i = 0; i < size; i++) {
result.add(IntegerMarshaller.INSTANCE.readPayload(dataIn));
}
return result;
}
@Override
public void writePayload(List<Integer> value, DataOutput dataOut) throws IOException {
dataOut.writeInt(value.size());
for (Integer integer : value) {
IntegerMarshaller.INSTANCE.writePayload(integer, dataOut);
}
}
}
}