/**
* 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.falcon.entity.v0;
import org.apache.falcon.FalconException;
import org.apache.falcon.entity.store.ConfigurationStore;
import org.apache.falcon.entity.v0.feed.Feed;
import org.apache.falcon.entity.v0.process.Cluster;
import org.apache.falcon.entity.v0.process.Input;
import org.apache.falcon.entity.v0.process.Output;
import org.apache.falcon.entity.v0.process.Process;
import org.apache.falcon.service.ConfigurationChangeListener;
import org.apache.log4j.Logger;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
/**
* An in-memory graph of entities and relationship among themselves.
*/
public final class EntityGraph implements ConfigurationChangeListener {
private static final Logger LOG = Logger.getLogger(EntityGraph.class);
private static EntityGraph instance = new EntityGraph();
private Map<Node, Set<Node>> graph = new ConcurrentHashMap<Node, Set<Node>>();
private EntityGraph() {
}
public static EntityGraph get() {
return instance;
}
public Set<Entity> getDependents(Entity entity) throws FalconException {
Node entityNode = new Node(entity.getEntityType(), entity.getName());
if (graph.containsKey(entityNode)) {
ConfigurationStore store = ConfigurationStore.get();
Set<Entity> dependents = new HashSet<Entity>();
for (Node node : graph.get(entityNode)) {
Entity dependentEntity = store.get(node.type, node.name);
assert dependentEntity != null : "Unable to find " + node;
dependents.add(dependentEntity);
}
return dependents;
} else {
return null;
}
}
@Override
public void onAdd(Entity entity) throws FalconException {
Map<Node, Set<Node>> nodeEdges = null;
switch (entity.getEntityType()) {
case PROCESS:
nodeEdges = getEdgesFor((Process) entity);
break;
case FEED:
nodeEdges = getEdgesFor((Feed) entity);
break;
default:
}
if (nodeEdges == null) {
return;
}
LOG.trace("Adding edges for " + entity.getName() + ": " + nodeEdges);
for (Map.Entry<Node, Set<Node>> entry : nodeEdges.entrySet()) {
if (graph.containsKey(entry.getKey())) {
graph.get(entry.getKey()).addAll(entry.getValue());
} else {
graph.put(entry.getKey(), entry.getValue());
}
}
LOG.trace("Merged edges to graph " + entity.getName());
}
@Override
public void onRemove(Entity entity) throws FalconException {
Map<Node, Set<Node>> nodeEdges = null;
switch (entity.getEntityType()) {
case PROCESS:
nodeEdges = getEdgesFor((Process) entity);
break;
case FEED:
nodeEdges = getEdgesFor((Feed) entity);
break;
default:
}
if (nodeEdges == null) {
return;
}
for (Map.Entry<Node, Set<Node>> entry : nodeEdges.entrySet()) {
if (graph.containsKey(entry.getKey())) {
graph.get(entry.getKey()).removeAll(entry.getValue());
if (graph.get(entry.getKey()).isEmpty()) {
graph.remove(entry.getKey());
}
}
}
}
@Override
public void onChange(Entity oldEntity, Entity newEntity) throws FalconException {
onRemove(oldEntity);
onAdd(newEntity);
}
private Map<Node, Set<Node>> getEdgesFor(Process process) {
Map<Node, Set<Node>> nodeEdges = new HashMap<Node, Set<Node>>();
Node processNode = new Node(EntityType.PROCESS, process.getName());
nodeEdges.put(processNode, new HashSet<Node>());
Set<Node> processEdges = nodeEdges.get(processNode);
if (process.getInputs() != null) {
for (Input input : process.getInputs().getInputs()) {
Node feedNode = new Node(EntityType.FEED, input.getFeed());
if (!nodeEdges.containsKey(feedNode)) {
nodeEdges.put(feedNode, new HashSet<Node>());
}
Set<Node> feedEdges = nodeEdges.get(feedNode);
processEdges.add(feedNode);
feedEdges.add(processNode);
}
}
if (process.getOutputs() != null) {
for (Output output : process.getOutputs().getOutputs()) {
Node feedNode = new Node(EntityType.FEED, output.getFeed());
if (!nodeEdges.containsKey(feedNode)) {
nodeEdges.put(feedNode, new HashSet<Node>());
}
Set<Node> feedEdges = nodeEdges.get(feedNode);
processEdges.add(feedNode);
feedEdges.add(processNode);
}
}
for (Cluster cluster : process.getClusters().getClusters()) {
Node clusterNode = new Node(EntityType.CLUSTER, cluster.getName());
processEdges.add(clusterNode);
nodeEdges.put(clusterNode, new HashSet<Node>());
nodeEdges.get(clusterNode).add(processNode);
}
return nodeEdges;
}
private Map<Node, Set<Node>> getEdgesFor(Feed feed) {
Map<Node, Set<Node>> nodeEdges = new HashMap<Node, Set<Node>>();
Node feedNode = new Node(EntityType.FEED, feed.getName());
Set<Node> feedEdges = new HashSet<Node>();
nodeEdges.put(feedNode, feedEdges);
for (org.apache.falcon.entity.v0.feed.Cluster cluster : feed.getClusters().getClusters()) {
Node clusterNode = new Node(EntityType.CLUSTER, cluster.getName());
if (!nodeEdges.containsKey(clusterNode)) {
nodeEdges.put(clusterNode, new HashSet<Node>());
}
Set<Node> clusterEdges = nodeEdges.get(clusterNode);
feedEdges.add(clusterNode);
clusterEdges.add(feedNode);
}
return nodeEdges;
}
/**
* Node element in the graph.
*/
private static final class Node {
private final EntityType type;
private final String name;
private Node(EntityType type, String name) {
this.type = type;
this.name = name;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
Node node = (Node) o;
boolean nameEqual = name != null ? !name.equals(node.name) : node.name != null;
if (nameEqual) {
return false;
}
if (type != node.type) {
return false;
}
return true;
}
@Override
public int hashCode() {
int result = type != null ? type.hashCode() : 0;
result = 31 * result + (name != null ? name.hashCode() : 0);
return result;
}
@Override
public String toString() {
return "(" + type + ") " + name;
}
}
}