com.ebay.nest.io.sede.columnar.BytesRefArrayWritable.java Source code

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Here is the source code for com.ebay.nest.io.sede.columnar.BytesRefArrayWritable.java

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/**
 * 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 com.ebay.nest.io.sede.columnar;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.Arrays;

import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableFactories;
import org.apache.hadoop.io.WritableFactory;

/**
 * <tt>BytesRefArrayWritable</tt> holds an array reference to BytesRefWritable,
 * and is able to resize without recreating new array if not necessary.
 * <p>
 *
 * Each <tt>BytesRefArrayWritable holds</tt> instance has a <i>valid</i> field,
 * which is the desired valid number of <tt>BytesRefWritable</tt> it holds.
 * <tt>resetValid</tt> can reset the valid, but it will not care the underlying
 * BytesRefWritable.
 */

public class BytesRefArrayWritable implements Writable, Comparable<BytesRefArrayWritable> {

    private BytesRefWritable[] bytesRefWritables = null;

    private int valid = 0;

    /**
     * Constructs an empty array with the specified capacity.
     *
     * @param capacity
     *          initial capacity
     * @exception IllegalArgumentException
     *              if the specified initial capacity is negative
     */
    public BytesRefArrayWritable(int capacity) {
        if (capacity < 0) {
            throw new IllegalArgumentException("Capacity can not be negative.");
        }
        bytesRefWritables = new BytesRefWritable[0];
        ensureCapacity(capacity);
    }

    /**
     * Constructs an empty array with a capacity of ten.
     */
    public BytesRefArrayWritable() {
        this(10);
    }

    /**
     * Returns the number of valid elements.
     *
     * @return the number of valid elements
     */
    public int size() {
        return valid;
    }

    /**
     * Gets the BytesRefWritable at the specified position. Make sure the position
     * is valid by first call resetValid.
     *
     * @param index
     *          the position index, starting from zero
     * @throws IndexOutOfBoundsException
     */
    public BytesRefWritable get(int index) {
        if (index >= valid) {
            throw new IndexOutOfBoundsException("This BytesRefArrayWritable only has " + valid + " valid values.");
        }
        return bytesRefWritables[index];
    }

    /**
     * Gets the BytesRefWritable at the specified position without checking.
     *
     * @param index
     *          the position index, starting from zero
     * @throws IndexOutOfBoundsException
     */
    public BytesRefWritable unCheckedGet(int index) {
        return bytesRefWritables[index];
    }

    /**
     * Set the BytesRefWritable at the specified position with the specified
     * BytesRefWritable.
     *
     * @param index
     *          index position
     * @param bytesRefWritable
     *          the new element
     * @throws IllegalArgumentException
     *           if the specified new element is null
     */
    public void set(int index, BytesRefWritable bytesRefWritable) {
        ensureCapacity(index + 1);
        bytesRefWritables[index] = bytesRefWritable;
        if (valid <= index) {
            valid = index + 1;
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int compareTo(BytesRefArrayWritable other) {
        if (other == null) {
            throw new IllegalArgumentException("Argument can not be null.");
        }
        if (this == other) {
            return 0;
        }
        int sizeDiff = valid - other.valid;
        if (sizeDiff != 0) {
            return sizeDiff;
        }
        for (int i = 0; i < valid; i++) {
            if (other.contains(bytesRefWritables[i])) {
                continue;
            } else {
                return 1;
            }
        }
        return 0;
    }

    /**
     * Returns <tt>true</tt> if this instance contains one or more the specified
     * BytesRefWritable.
     *
     * @param bytesRefWritable
     *          BytesRefWritable element to be tested
     * @return <tt>true</tt> if contains the specified element
     * @throws IllegalArgumentException
     *           if the specified element is null
     */
    public boolean contains(BytesRefWritable bytesRefWritable) {
        if (bytesRefWritable == null) {
            throw new IllegalArgumentException("Argument can not be null.");
        }
        for (int i = 0; i < valid; i++) {
            if (bytesRefWritables[i].equals(bytesRefWritable)) {
                return true;
            }
        }
        return false;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean equals(Object o) {
        if (o == null || !(o instanceof BytesRefArrayWritable)) {
            return false;
        }
        return compareTo((BytesRefArrayWritable) o) == 0;
    }

    /**
     * Removes all elements.
     */
    public void clear() {
        valid = 0;
    }

    /**
     * enlarge the capacity if necessary, to ensure that it can hold the number of
     * elements specified by newValidCapacity argument. It will also narrow the
     * valid capacity when needed. Notice: it only enlarge or narrow the valid
     * capacity with no care of the already stored invalid BytesRefWritable.
     *
     * @param newValidCapacity
     *          the desired capacity
     */
    public void resetValid(int newValidCapacity) {
        ensureCapacity(newValidCapacity);
        valid = newValidCapacity;
    }

    protected void ensureCapacity(int newCapacity) {
        int size = bytesRefWritables.length;
        if (size < newCapacity) {
            bytesRefWritables = Arrays.copyOf(bytesRefWritables, newCapacity);
            while (size < newCapacity) {
                bytesRefWritables[size] = new BytesRefWritable();
                size++;
            }
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void readFields(DataInput in) throws IOException {
        int count = in.readInt();
        ensureCapacity(count);
        for (int i = 0; i < count; i++) {
            bytesRefWritables[i].readFields(in);
        }
        valid = count;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void write(DataOutput out) throws IOException {
        out.writeInt(valid);

        for (int i = 0; i < valid; i++) {
            BytesRefWritable cu = bytesRefWritables[i];
            cu.write(out);
        }
    }

    static {
        WritableFactories.setFactory(BytesRefArrayWritable.class, new WritableFactory() {

            @Override
            public Writable newInstance() {
                return new BytesRefArrayWritable();
            }

        });
    }
}