io.horizondb.io.serialization.Serializables.java Source code

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Here is the source code for io.horizondb.io.serialization.Serializables.java

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/**
 * Copyright 2013 Benjamin Lerer
 * 
 * Licensed 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 io.horizondb.io.serialization;

import io.horizondb.io.ByteReader;
import io.horizondb.io.ByteWriter;
import io.horizondb.io.encoding.VarInts;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.annotation.concurrent.Immutable;

import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;

/**
 * A composite <code>Serializable</code>.
 * 
 * @author Benjamin
 * 
 */
@Immutable
public final class Serializables<T extends Serializable> implements Iterable<T>, Serializable {

    /**
     * The composing serializables.
     */
    private final List<T> serializables;

    /**
     * Creates a new composite composed of the specified serializables
     * 
     * @param serializables the serializables.
     */
    public Serializables(List<T> serializables) {

        this.serializables = new ArrayList<>(serializables);
    }

    /**
     * Returns the serializable at the specified index.
     * 
     * @param index the serializable index.
     * @return the serializable at the specified index.
     */
    public T get(int index) {

        return this.serializables.get(index);
    }

    /**
     * Returns the number of serializables composing this <code>Serializables</code>.
     * 
     * @return the number of serializables composing this <code>Serializables</code>.
     */
    public int size() {

        return this.serializables.size();
    }

    /**    
     * {@inheritDoc}
     */
    @Override
    public Iterator<T> iterator() {
        return this.serializables.iterator();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int computeSerializedSize() throws IOException {

        int size = VarInts.computeUnsignedIntSize(this.serializables.size());

        for (int i = 0, m = this.serializables.size(); i < m; i++) {

            size += this.serializables.get(i).computeSerializedSize();
        }

        return size;
    }

    public static <S extends Serializable> Serializables<S> parseFrom(Parser<S> parser, ByteReader reader)
            throws IOException {

        return new SerializablesParser<S>(parser).parseFrom(reader);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void writeTo(ByteWriter writer) throws IOException {

        VarInts.writeUnsignedInt(writer, this.serializables.size());

        for (int i = 0, m = this.serializables.size(); i < m; i++) {

            this.serializables.get(i).writeTo(writer);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean equals(Object object) {
        if (object == this) {
            return true;
        }
        if (!(object instanceof Serializables)) {
            return false;
        }
        @SuppressWarnings("unchecked")
        Serializables<T> rhs = (Serializables<T>) object;
        return new EqualsBuilder().append(this.serializables, rhs.serializables).isEquals();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int hashCode() {
        return new HashCodeBuilder(252469533, 1404885147).append(this.serializables).toHashCode();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toString() {
        return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE)
                .append("serializables", this.serializables).toString();
    }

    /**
     * The parser for the <code>Serializables</code>.
     * 
     * @param <T> the type of the composing <code>Serializable</code>
     */
    private static final class SerializablesParser<T extends Serializable> implements Parser<Serializables<T>> {

        /**
         * The parser for the serializable instances.
         */
        private final Parser<T> parser;

        public SerializablesParser(Parser<T> parser) {
            this.parser = parser;
        }

        /**
         * {@inheritDoc}
         */
        @Override
        public Serializables<T> parseFrom(ByteReader reader) throws IOException {

            int size = VarInts.readUnsignedInt(reader);

            List<T> serializables = new ArrayList<>(size);

            for (int i = 0; i < size; i++) {

                serializables.add(this.parser.parseFrom(reader));
            }

            return new Serializables<>(serializables);
        }
    }
}