eu.stratosphere.nephele.instance.InstanceRequestMap Maven / Gradle / Ivy
/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.nephele.instance;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
/**
* An instance request map specifies the required types of instances to run a specific job and the respective number
* thereof. For each instance type it is possible to specify the minimum number of instances required to run the job. If
* the {@link InstanceManager} cannot manage to provide at least this minimum numbers of instances for the given type,
* the job will be rejected.
*
* In addition, is it also possible to specify the optimal number of instances for a particular instance type. The
* {@link InstanceManager} will try to provide this optimal number of instances, but will also start the job with less
* instances.
*
* This class is not thread-safe.
*
*/
public final class InstanceRequestMap {
/**
* The map holding the minimum number of instances to be requested for each instance type.
*/
private final Map minimumMap = new HashMap();
/**
* The map holding the maximum number of instances to be requested for each instance type.
*/
private final Map maximumMap = new HashMap();
/**
* Sets the minimum number of instances to be requested from the given instance type.
*
* @param instanceType
* the type of instance to request
* @param number
* the minimum number of instances to request
*/
public void setMinimumNumberOfInstances(final InstanceType instanceType, final int number) {
this.minimumMap.put(instanceType, Integer.valueOf(number));
}
/**
* Sets the maximum number of instances to be requested from the given instance type.
*
* @param instanceType
* the type of instance to request
* @param number
* the maximum number of instances to request
*/
public void setMaximumNumberOfInstances(final InstanceType instanceType, final int number) {
this.maximumMap.put(instanceType, Integer.valueOf(number));
}
/**
* Sets both the minimum and the maximum number of instances to be requested from the given instance type.
*
* @param instanceType
* the type of instance to request
* @param number
* the minimum and the maximum number of instances to request
*/
public void setNumberOfInstances(final InstanceType instanceType, final int number) {
setMinimumNumberOfInstances(instanceType, number);
setMaximumNumberOfInstances(instanceType, number);
}
/**
* Returns the minimum number of instances to be requested from the given instance type.
*
* @param instanceType
* the type of instance to request
* @return the minimum number of instances to be requested from the given instance type
*/
public int getMinimumNumberOfInstances(final InstanceType instanceType) {
final Integer val = this.minimumMap.get(instanceType);
if (val != null) {
return val.intValue();
}
return 0;
}
/**
* Returns the maximum number of instances to be requested from the given instance type.
*
* @param instanceType
* the type of instance to request
* @return the maximum number of instances to be requested from the given instance type
*/
public int getMaximumNumberOfInstances(final InstanceType instanceType) {
final Integer val = this.maximumMap.get(instanceType);
if (val != null) {
return val.intValue();
}
return 0;
}
/**
* Checks if this instance request map is empty, i.e. neither contains an entry for the minimum or maximum number of
* instances to be requested for any instance type.
*
* @return true if the map is empty, false otherwise
*/
public boolean isEmpty() {
if (!this.maximumMap.isEmpty()) {
return false;
}
if (!this.minimumMap.isEmpty()) {
return false;
}
return true;
}
/**
* Returns an {@link Iterator} object which allows to traverse the minimum number of instances to be requested for
* each instance type.
*
* @return an iterator to traverse the minimum number of instances to be requested for each instance type
*/
public Iterator> getMaximumIterator() {
return this.maximumMap.entrySet().iterator();
}
/**
* Returns an {@link Iterator} object which allows to traverse the maximum number of instances to be requested for
* each instance type.
*
* @return an iterator to traverse the maximum number of instances to be requested for each instance type
*/
public Iterator> getMinimumIterator() {
return this.minimumMap.entrySet().iterator();
}
/**
* Returns the number of different instance types stored in this request map.
*
* @return the number of different instance types stored in this request map
*/
public int size() {
final int s = this.maximumMap.size();
if (s != this.minimumMap.size()) {
throw new IllegalStateException("InstanceRequestMap is in an inconsistent state");
}
return s;
}
/**
* Clears the instance request map.
*/
public void clear() {
this.maximumMap.clear();
this.minimumMap.clear();
}
}