/tags/release-0.1-rc2/hive/external/serde/src/java/org/apache/hadoop/hive/serde2/columnar/BytesRefArrayWritable.java
Java | 256 lines | 128 code | 25 blank | 103 comment | 26 complexity | aed2b8f7b58a19fd38812b35d7b3b5bd MD5 | raw file
Possible License(s): Apache-2.0, BSD-3-Clause, JSON, CPL-1.0
- /**
- * 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.hive.serde2.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) {
- if (bytesRefWritable == null) {
- throw new IllegalArgumentException("Can not assign null.");
- }
- 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();
- }
- });
- }
- }