/*
* 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.brooklyn.core.location;
import static com.google.common.base.Preconditions.checkState;
import java.io.Closeable;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.brooklyn.api.location.MachineLocation;
import org.apache.brooklyn.api.location.MachineProvisioningLocation;
import org.apache.brooklyn.api.location.NoMachinesAvailableException;
import org.apache.brooklyn.util.core.flags.SetFromFlag;
import org.apache.brooklyn.util.stream.Streams;
import com.google.common.base.Objects;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
/**
* Takes a list of other provisioners, and round-robins across them when obtaining a machine.
*/
public class AggregatingMachineProvisioningLocation<T extends MachineLocation> extends AbstractLocation
implements MachineProvisioningLocation<T>, Closeable {
private Object lock;
@SetFromFlag
protected List<MachineProvisioningLocation<T>> provisioners;
@SetFromFlag
protected Map<T, MachineProvisioningLocation<T>> inUse;
protected final AtomicInteger obtainCounter = new AtomicInteger();
public AggregatingMachineProvisioningLocation() {
this(Maps.newLinkedHashMap());
}
public AggregatingMachineProvisioningLocation(Map properties) {
super(properties);
if (isLegacyConstruction()) {
init();
}
}
@Override
public void init() {
super.init();
}
@Override
public String toVerboseString() {
return Objects.toStringHelper(this).omitNullValues()
.add("id", getId()).add("name", getDisplayName())
.add("provisioners", provisioners)
.toString();
}
@Override
public AbstractLocation configure(Map<?,?> properties) {
if (lock == null) {
lock = new Object();
provisioners = Lists.<MachineProvisioningLocation<T>>newArrayList();
inUse = Maps.<T, MachineProvisioningLocation<T>>newLinkedHashMap();
}
return super.configure(properties);
}
@Override
public AggregatingMachineProvisioningLocation<T> newSubLocation(Map<?,?> newFlags) {
throw new UnsupportedOperationException();
}
@Override
public void close() {
for (MachineProvisioningLocation<?> provisioner : provisioners) {
if (provisioner instanceof Closeable) {
Streams.closeQuietly((Closeable)provisioner);
}
}
}
public T obtain() throws NoMachinesAvailableException {
return obtain(Maps.<String,Object>newLinkedHashMap());
}
@Override
public T obtain(Map<?,?> flags) throws NoMachinesAvailableException {
checkState(provisioners.size() > 0, "no provisioners!");
int index = obtainCounter.getAndIncrement();
for (int i = 0; i < provisioners.size(); i++) {
MachineProvisioningLocation<T> provisioner = provisioners.get(index++ % provisioners.size());
try {
T machine = provisioner.obtain(flags);
inUse.put(machine, provisioner);
return machine;
} catch (NoMachinesAvailableException e) {
// move on; try next
}
}
throw new NoMachinesAvailableException("No machines available in "+toString());
}
@Override
public void release(T machine) {
MachineProvisioningLocation<T> provisioner = inUse.remove(machine);
if (provisioner != null) {
provisioner.release(machine);
} else {
throw new IllegalStateException("Request to release machine "+machine+", but this machine is not currently allocated");
}
}
@Override
public Map<String,Object> getProvisioningFlags(Collection<String> tags) {
return Maps.<String,Object>newLinkedHashMap();
}
}