/**
* 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.hadoop.ipc;
import org.apache.hadoop.classification.InterfaceAudience;
/**
* The IdentityProvider creates identities for each schedulable
* by extracting fields and returning an identity string.
*
* Implementers will be able to change how schedulers treat
* Schedulables.
*/
@InterfaceAudience.Private
public interface IdentityProvider {
/**
* Return the string used for scheduling.
* @param obj the schedulable to use.
* @return string identity, or null if no identity could be made.
*/
public String makeIdentity(Schedulable obj);
}