| /** |
| * 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.io; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import java.util.EnumSet; |
| import java.util.Iterator; |
| import java.util.AbstractCollection; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configurable; |
| import org.apache.hadoop.conf.Configuration; |
| |
| /** A Writable wrapper for EnumSet. */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public class EnumSetWritable<E extends Enum<E>> extends AbstractCollection<E> |
| implements Writable, Configurable { |
| |
| private EnumSet<E> value; |
| |
| private transient Class<E> elementType; |
| |
| private transient Configuration conf; |
| |
| EnumSetWritable() { |
| } |
| |
| @Override |
| public Iterator<E> iterator() { return value.iterator(); } |
| @Override |
| public int size() { return value.size(); } |
| @Override |
| public boolean add(E e) { |
| if (value == null) { |
| value = EnumSet.of(e); |
| set(value, null); |
| } |
| return value.add(e); |
| } |
| |
| /** |
| * Construct a new EnumSetWritable. If the <tt>value</tt> argument is null or |
| * its size is zero, the <tt>elementType</tt> argument must not be null. If |
| * the argument <tt>value</tt>'s size is bigger than zero, the argument |
| * <tt>elementType</tt> is not be used. |
| * |
| * @param value |
| * @param elementType |
| */ |
| public EnumSetWritable(EnumSet<E> value, Class<E> elementType) { |
| set(value, elementType); |
| } |
| |
| /** |
| * Construct a new EnumSetWritable. Argument <tt>value</tt> should not be null |
| * or empty. |
| * |
| * @param value |
| */ |
| public EnumSetWritable(EnumSet<E> value) { |
| this(value, null); |
| } |
| |
| /** |
| * reset the EnumSetWritable with specified |
| * <tt>value</value> and <tt>elementType</tt>. If the <tt>value</tt> argument |
| * is null or its size is zero, the <tt>elementType</tt> argument must not be |
| * null. If the argument <tt>value</tt>'s size is bigger than zero, the |
| * argument <tt>elementType</tt> is not be used. |
| * |
| * @param value |
| * @param elementType |
| */ |
| public void set(EnumSet<E> value, Class<E> elementType) { |
| if ((value == null || value.size() == 0) |
| && (this.elementType == null && elementType == null)) { |
| throw new IllegalArgumentException( |
| "The EnumSet argument is null, or is an empty set but with no elementType provided."); |
| } |
| this.value = value; |
| if (value != null && value.size() > 0) { |
| Iterator<E> iterator = value.iterator(); |
| this.elementType = iterator.next().getDeclaringClass(); |
| } else if (elementType != null) { |
| this.elementType = elementType; |
| } |
| } |
| |
| /** Return the value of this EnumSetWritable. */ |
| public EnumSet<E> get() { |
| return value; |
| } |
| |
| @Override |
| @SuppressWarnings("unchecked") |
| public void readFields(DataInput in) throws IOException { |
| int length = in.readInt(); |
| if (length == -1) |
| this.value = null; |
| else if (length == 0) { |
| this.elementType = (Class<E>) ObjectWritable.loadClass(conf, |
| WritableUtils.readString(in)); |
| this.value = EnumSet.noneOf(this.elementType); |
| } else { |
| E first = (E) ObjectWritable.readObject(in, conf); |
| this.value = (EnumSet<E>) EnumSet.of(first); |
| for (int i = 1; i < length; i++) |
| this.value.add((E) ObjectWritable.readObject(in, conf)); |
| } |
| } |
| |
| @Override |
| public void write(DataOutput out) throws IOException { |
| if (this.value == null) { |
| out.writeInt(-1); |
| WritableUtils.writeString(out, this.elementType.getName()); |
| } else { |
| Object[] array = this.value.toArray(); |
| int length = array.length; |
| out.writeInt(length); |
| if (length == 0) { |
| if (this.elementType == null) |
| throw new UnsupportedOperationException( |
| "Unable to serialize empty EnumSet with no element type provided."); |
| WritableUtils.writeString(out, this.elementType.getName()); |
| } |
| for (int i = 0; i < length; i++) { |
| ObjectWritable.writeObject(out, array[i], array[i].getClass(), conf); |
| } |
| } |
| } |
| |
| /** |
| * Returns true if <code>o</code> is an EnumSetWritable with the same value, |
| * or both are null. |
| */ |
| @Override |
| public boolean equals(Object o) { |
| if (o == null) { |
| throw new IllegalArgumentException("null argument passed in equal()."); |
| } |
| |
| if (!(o instanceof EnumSetWritable)) |
| return false; |
| |
| EnumSetWritable<?> other = (EnumSetWritable<?>) o; |
| |
| if (this == o || (this.value == other.value)) |
| return true; |
| if (this.value == null) // other.value must not be null if we reach here |
| return false; |
| |
| return this.value.equals(other.value); |
| } |
| |
| /** |
| * Returns the class of all the elements of the underlying EnumSetWriable. It |
| * may return null. |
| * |
| * @return the element class |
| */ |
| public Class<E> getElementType() { |
| return elementType; |
| } |
| |
| @Override |
| public int hashCode() { |
| if (value == null) |
| return 0; |
| return (int) value.hashCode(); |
| } |
| |
| @Override |
| public String toString() { |
| if (value == null) |
| return "(null)"; |
| return value.toString(); |
| } |
| |
| @Override |
| public Configuration getConf() { |
| return this.conf; |
| } |
| |
| @Override |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| } |
| |
| static { |
| WritableFactories.setFactory(EnumSetWritable.class, new WritableFactory() { |
| @SuppressWarnings("unchecked") |
| @Override |
| public Writable newInstance() { |
| return new EnumSetWritable(); |
| } |
| }); |
| } |
| } |