| /* |
| * 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.giraph.graph; |
| |
| import org.apache.giraph.edge.Edge; |
| import org.apache.giraph.utils.UnsafeByteArrayInputStream; |
| import org.apache.giraph.utils.UnsafeByteArrayOutputStream; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableComparable; |
| |
| import java.io.DataInput; |
| import java.io.IOException; |
| |
| |
| /** |
| * Special version of vertex that holds the value in raw byte form to save |
| * memory. |
| * |
| * @param <I> Vertex id |
| * @param <V> Vertex data |
| * @param <E> Edge data |
| */ |
| public class ByteValueVertex<I extends WritableComparable, |
| V extends Writable, E extends Writable> |
| extends DefaultVertex<I, V, E> { |
| |
| /** Vertex value stored as raw bytes */ |
| private byte[] valueBytes; |
| /** Value as an cached object that is only valid during the vertex update */ |
| private V cachedValue = null; |
| |
| @Override |
| public V getValue() { |
| if (cachedValue != null) { |
| return cachedValue; // Return always same instance |
| } |
| DataInput dis = new UnsafeByteArrayInputStream(valueBytes); |
| cachedValue = getConf().createVertexValue(); |
| try { |
| cachedValue.readFields(dis); |
| } catch (IOException ioe) { |
| throw new RuntimeException("Could not deserialize vertex value", ioe); |
| } |
| // Forget the serialized data, because we have cached the object |
| valueBytes = null; |
| return cachedValue; |
| } |
| |
| /** |
| * Serializes the value to bytes, stored in field valueBytes |
| * @param value new vertex value |
| */ |
| private void setSerializedValue(V value) { |
| UnsafeByteArrayOutputStream bos = new UnsafeByteArrayOutputStream(); |
| try { |
| value.write(bos); |
| bos.close(); |
| } catch (IOException ioe) { |
| throw new RuntimeException("Could not serialize vertex value", ioe); |
| } |
| this.valueBytes = bos.toByteArray(); |
| cachedValue = null; |
| } |
| |
| @Override |
| public void setValue(V value) { |
| if (cachedValue != null) { |
| cachedValue = value; |
| } else { |
| setSerializedValue(value); |
| } |
| } |
| |
| @Override |
| public void initialize(I id, V value, Iterable<Edge<I, E>> edges) { |
| // Set the parent's value to null, and instead use our own setter |
| super.initialize(id, null, edges); |
| setValue(value); |
| } |
| |
| @Override |
| public void initialize(I id, V value) { |
| super.initialize(id, null); |
| setValue(value); |
| } |
| |
| @Override |
| public void unwrapMutableEdges() { |
| // This method is called always after compute(vertex), so |
| // we use this to commit the vertex value. |
| if (cachedValue != null) { |
| // This means the value has been requested from vertex |
| // and possible mutated -- so we need to update the byte array |
| setSerializedValue(cachedValue); |
| cachedValue = null; // Uncache the value |
| } |
| super.unwrapMutableEdges(); |
| } |
| } |