/*
* 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.spargel.java.record;
import java.io.Serializable;
import java.util.Iterator;
import org.apache.flink.api.common.aggregators.Aggregator;
import org.apache.flink.api.common.functions.IterationRuntimeContext;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.types.Key;
import org.apache.flink.types.Record;
import org.apache.flink.types.Value;
import org.apache.flink.util.Collector;
public abstract class MessagingFunction<VertexKey extends Key<VertexKey>, VertexValue extends Value, Message extends Value, EdgeValue extends Value> implements Serializable {
// --------------------------------------------------------------------------------------------
// Public API Methods
// --------------------------------------------------------------------------------------------
public abstract void sendMessages(VertexKey vertexKey, VertexValue vertexValue) throws Exception;
public void setup(Configuration config) throws Exception {}
public void preSuperstep() throws Exception {}
public void postSuperstep() throws Exception {}
public Iterator<Edge<VertexKey, EdgeValue>> getOutgoingEdges() {
if (edgesUsed) {
throw new IllegalStateException("Can use either 'getOutgoingEdges()' or 'sendMessageToAllTargets()'.");
}
edgesUsed = true;
edgeIter.set(edges);
return edgeIter;
}
public void sendMessageToAllNeighbors(Message m) {
if (edgesUsed) {
throw new IllegalStateException("Can use either 'getOutgoingEdges()' or 'sendMessageToAllTargets()'.");
}
edgesUsed = true;
while (edges.hasNext()) {
Record next = edges.next();
VertexKey k = next.getField(1, this.keyClass);
outValue.setField(0, k);
outValue.setField(1, m);
out.collect(outValue);
}
}
public void sendMessageTo(VertexKey target, Message m) {
outValue.setField(0, target);
outValue.setField(1, m);
out.collect(outValue);
}
// --------------------------------------------------------------------------------------------
public int getSuperstep() {
return this.runtimeContext.getSuperstepNumber();
}
public <T extends Aggregator<?>> T getIterationAggregator(String name) {
return this.runtimeContext.<T>getIterationAggregator(name);
}
public <T extends Value> T getPreviousIterationAggregate(String name) {
return this.runtimeContext.<T>getPreviousIterationAggregate(name);
}
// --------------------------------------------------------------------------------------------
// internal methods and state
// --------------------------------------------------------------------------------------------
private Record outValue;
private IterationRuntimeContext runtimeContext;
private Iterator<Record> edges;
private Collector<Record> out;
private EdgesIterator<VertexKey, EdgeValue> edgeIter;
private Class<VertexKey> keyClass;
private boolean edgesUsed;
@SuppressWarnings("unchecked")
void init(IterationRuntimeContext context, VertexKey keyHolder, EdgeValue edgeValueHolder) {
this.runtimeContext = context;
this.edgeIter = new EdgesIterator<VertexKey, EdgeValue>(keyHolder, edgeValueHolder);
this.outValue = new Record();
this.keyClass = (Class<VertexKey>) keyHolder.getClass();
}
void set(Iterator<Record> edges, Collector<Record> out) {
this.edges = edges;
this.out = out;
this.edgesUsed = false;
}
private static final long serialVersionUID = 1L;
private static final class EdgesIterator<VertexKey extends Key<VertexKey>, EdgeValue extends Value> implements Iterator<Edge<VertexKey, EdgeValue>> {
private Iterator<Record> input;
private VertexKey keyHolder;
private EdgeValue edgeValueHolder;
private Edge<VertexKey, EdgeValue> edge = new Edge<VertexKey, EdgeValue>();
EdgesIterator(VertexKey keyHolder, EdgeValue edgeValueHolder) {
this.keyHolder = keyHolder;
this.edgeValueHolder = edgeValueHolder;
}
void set(Iterator<Record> input) {
this.input = input;
}
@Override
public boolean hasNext() {
return input.hasNext();
}
@Override
public Edge<VertexKey, EdgeValue> next() {
Record next = input.next();
next.getFieldInto(0, keyHolder);
next.getFieldInto(1, edgeValueHolder);
edge.set(keyHolder, edgeValueHolder);
return edge;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
}