org.apache.flink.runtime.checkpoint.ExecutionAttemptMappingProvider Maven / Gradle / Ivy
/*
* 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.flink.runtime.checkpoint;
import org.apache.flink.runtime.executiongraph.ExecutionAttemptID;
import org.apache.flink.runtime.executiongraph.ExecutionVertex;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
/**
* Provides a mapping from {@link ExecutionAttemptID} to {@link ExecutionVertex} for currently
* running execution attempts.
*/
public class ExecutionAttemptMappingProvider {
/** A full list of tasks. */
private final List tasks;
/** The cached mapping, which would only be updated on miss. */
private final LinkedHashMap cachedTasksById;
public ExecutionAttemptMappingProvider(Iterable tasksIterable) {
this.tasks = new ArrayList<>();
tasksIterable.forEach(this.tasks::add);
this.cachedTasksById =
new LinkedHashMap(tasks.size()) {
@Override
protected boolean removeEldestEntry(
Map.Entry eldest) {
return size() > tasks.size();
}
};
}
public Optional getVertex(ExecutionAttemptID id) {
if (!cachedTasksById.containsKey(id)) {
cachedTasksById.putAll(getCurrentAttemptMappings());
if (!cachedTasksById.containsKey(id)) {
// the task probably gone after a restart
cachedTasksById.put(id, null);
}
}
return Optional.ofNullable(cachedTasksById.get(id));
}
private Map getCurrentAttemptMappings() {
Map attemptMappings = new HashMap<>(tasks.size());
for (ExecutionVertex task : tasks) {
attemptMappings.put(task.getCurrentExecutionAttempt().getAttemptId(), task);
}
return attemptMappings;
}
}