/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
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* or http://forgerock.org/license/CDDLv1.0.html.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at legal-notices/CDDLv1_0.txt.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Copyright 2009-2010 Sun Microsystems, Inc.
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* Portions Copyright 2013-2015 ForgeRock AS.
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*/
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package org.opends.server.backends.pluggable;
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import static org.opends.server.backends.pluggable.Importer.indexComparator;
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import java.io.ByteArrayOutputStream;
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import java.io.DataOutputStream;
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import java.io.IOException;
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import java.nio.ByteBuffer;
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import org.forgerock.opendj.ldap.ByteSequence;
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/**
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* This class represents a index buffer used to store the keys and entry IDs
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* processed from the LDIF file during phase one of an import, or rebuild index
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* process. Each key and ID is stored in a record in the buffer.
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* <p>
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* The records in the buffer are eventually sorted, based on the key, when the
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* maximum size of the buffer is reached and no more records will fit into the
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* buffer. The buffer is scheduled to be flushed to an index scratch file and
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* then re-cycled by the import, or rebuild-index process.
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* </p>
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* <p>
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* The structure of a record in the buffer is the following:
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*
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* <pre>
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* +-------------+-------------+---------+---------+------------+-----------+
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* | record size | INS/DEL bit | indexID | entryID | key length | key bytes |
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* +-------------+-------------+---------+---------+------------+-----------+
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* </pre>
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*
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* The record size is used for fast seeks to quickly "jump" over records.
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* </p>
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* <p>
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* The records are packed as much as possible, to optimize the buffer space.
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* </p>
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* <p>
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* This class is not thread safe.
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* </p>
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*/
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final class IndexOutputBuffer implements Comparable<IndexOutputBuffer> {
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/** The number of bytes of a Java int. */
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static final int INT_SIZE = 4;
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/** The number of bytes of a Java long. */
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static final int LONG_SIZE = 8;
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/**
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* The record overhead. In addition to entryID, key length and key bytes, the
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* record overhead includes the INS/DEL bit + indexID
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*/
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private static final int REC_OVERHEAD = 1 + INT_SIZE;
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/** Buffer records are either insert records or delete records. */
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private static final byte DEL = 0, INS = 1;
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/** The size of a buffer. */
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private final int size;
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/** Byte array holding the actual buffer data. */
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private final byte buffer[];
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/**
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* Used to break a tie (keys equal) when the buffers are being merged
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* for writing to the index scratch file.
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*/
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private long bufferID;
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/** OffSet where next key is written. */
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private int keyOffset;
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/** OffSet where next value record is written. */
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private int recordOffset;
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/** Amount of bytes left in the buffer. */
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private int bytesLeft;
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/** Number of keys in the buffer. */
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private int keys;
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/** Used to iterate over the buffer when writing to a scratch file. */
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private int position;
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/**
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* Used to make sure that an instance of this class is put on the
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* correct scratch file writer work queue for processing.
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*/
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private Importer.IndexKey indexKey;
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/** Initial capacity of re-usable buffer used in key compares. */
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private static final int CAP = 32;
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/**
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* This buffer is reused during key compares. It's main purpose is to keep
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* memory footprint as small as possible.
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*/
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private ByteBuffer keyBuffer = ByteBuffer.allocate(CAP);
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/**
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* Set to {@code true} if the buffer should not be recycled. Used when the
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* importer/rebuild index process is doing phase one cleanup and flushing
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* buffers not completed.
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*/
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private boolean discarded;
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/**
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* Create an instance of a IndexBuffer using the specified size.
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*
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* @param size The size of the underlying byte array.
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*/
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public IndexOutputBuffer(int size) {
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this.size = size;
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this.buffer = new byte[size];
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this.bytesLeft = size;
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this.recordOffset = size - 1;
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}
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/**
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* Reset an IndexBuffer so it can be re-cycled.
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*/
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public void reset() {
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bytesLeft = size;
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keyOffset = 0;
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recordOffset = size - 1;
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keys = 0;
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position = 0;
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indexKey = null;
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}
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/**
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* Creates a new poison buffer. Poison buffers are used to stop the processing of import tasks.
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*
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* @return a new poison buffer
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*/
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public static IndexOutputBuffer poison()
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{
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return new IndexOutputBuffer(0);
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}
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/**
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* Set the ID of a buffer to the specified value.
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*
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* @param bufferID The value to set the buffer ID to.
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*/
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public void setBufferID(long bufferID)
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{
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this.bufferID = bufferID;
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}
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/**
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* Return the ID of a buffer.
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*
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* @return The value of a buffer's ID.
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*/
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private long getBufferID()
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{
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return this.bufferID;
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}
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/**
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* Determines if a buffer is a poison buffer. A poison buffer is used to
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* shutdown work queues when import/rebuild index phase one is completed.
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* A poison buffer has a 0 size.
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*
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* @return {@code true} if a buffer is a poison buffer, or {@code false}
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* otherwise.
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*/
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public boolean isPoison()
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{
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return size == 0;
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}
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/**
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* Determines if buffer should be re-cycled by calling {@link #reset()}.
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*
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* @return {@code true} if buffer should be recycled, or {@code false} if it should not.
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*/
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boolean isDiscarded()
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{
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return discarded;
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}
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/**
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* Sets the discarded flag to {@code true}.
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*/
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public void discard()
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{
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discarded = true;
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}
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/**
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* Returns {@code true} if there is enough space available to write the
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* specified byte array in the buffer. It returns {@code false} otherwise.
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*
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* @param kBytes The byte array to check space against.
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* @param entryID The entryID value to check space against.
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* @return {@code true} if there is space to write the byte array in a
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* buffer, or {@code false} otherwise.
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*/
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public boolean isSpaceAvailable(ByteSequence kBytes, long entryID) {
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return getRequiredSize(kBytes.length(), entryID) < bytesLeft;
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}
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/**
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* Return a buffer's current position value.
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*
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* @return The buffer's current position value.
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*/
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public int getPosition()
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{
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return position;
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}
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/**
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* Set a buffer's position value to the specified position.
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*
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* @param position The value to set the position to.
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*/
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public void setPosition(int position)
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{
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this.position = position;
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}
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/**
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* Sort the buffer.
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*/
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public void sort() {
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sort(0, keys);
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}
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/**
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* Add the specified key byte array and EntryID to the buffer.
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*
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* @param keyBytes The key byte array.
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* @param entryID The EntryID.
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* @param indexID The index ID the record belongs.
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* @param insert <CODE>True</CODE> if key is an insert, false otherwise.
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*/
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public void add(ByteSequence keyBytes, EntryID entryID, int indexID, boolean insert) {
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// write the record data, but leave the space to write the record size just
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// before it
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recordOffset = addRecord(keyBytes, entryID.longValue(), indexID, insert);
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// then write the returned record size
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keyOffset = writeInt(buffer, keyOffset, recordOffset);
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bytesLeft = recordOffset - keyOffset;
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keys++;
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}
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/**
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* Writes the full record minus the record size itself.
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*/
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private int addRecord(ByteSequence key, long entryID, int indexID, boolean insert)
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{
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int retOffset = recordOffset - getRecordSize(key.length());
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int offSet = retOffset;
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// write the INS/DEL bit
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buffer[offSet++] = insert ? INS : DEL;
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// write the indexID
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offSet = writeInt(buffer, offSet, indexID);
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// write the entryID
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offSet = writeLong(buffer, offSet, entryID);
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// write the key length
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offSet = writeInt(buffer, offSet, key.length());
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// write the key bytes
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key.copyTo(buffer, offSet);
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return retOffset;
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}
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/**
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* Computes the full size of the record.
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*
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* @param keyLen The length of the key of index
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* @param entryID The entry id
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* @return The size that such record would take in the IndexOutputBuffer
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*/
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public static int getRequiredSize(int keyLen, long entryID)
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{
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// also add up the space needed to store the record size
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return getRecordSize(keyLen) + INT_SIZE;
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}
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private static int getRecordSize(int keyLen)
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{
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// Adds up (INS/DEL bit + indexID) + entryID + key length + key bytes
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return REC_OVERHEAD + LONG_SIZE + INT_SIZE + keyLen;
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}
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/**
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* Write the entryID at the specified position to the specified output stream.
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* Used when writing the index scratch files.
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*
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* @param stream The stream to write the record at the index to.
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* @param position The position of the record to write.
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*/
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public void writeEntryID(ByteArrayOutputStream stream, int position)
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{
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int offSet = getOffset(position);
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stream.write(buffer, offSet + REC_OVERHEAD, LONG_SIZE);
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}
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/**
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* Return {@code true} if the record specified by the position is an insert
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* record, or {@code false} if it a delete record.
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*
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* @param position The position of the record.
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* @return {@code true} if the record is an insert record, or {@code false}
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* if it is a delete record.
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*/
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public boolean isInsertRecord(int position)
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{
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int recOffset = getOffset(position);
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return buffer[recOffset] == INS;
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}
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/**
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* Return the size of the key part of the record.
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*
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* @return The size of the key part of the record.
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*/
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public int getKeySize()
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{
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int offSet = getOffset(position) + REC_OVERHEAD + LONG_SIZE;
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return readInt(buffer, offSet);
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}
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/**
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* Return the key value part of a record indicated by the current buffer
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* position.
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*
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* @return byte array containing the key value.
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*/
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public byte[] getKey()
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{
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return getKey(position);
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}
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/** Used to minimized memory usage when comparing keys. */
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private ByteBuffer getKeyBuf(int position)
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{
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keyBuffer.clear();
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int offSet = getOffset(position) + REC_OVERHEAD + LONG_SIZE;
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int keyLen = readInt(buffer, offSet);
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offSet += INT_SIZE;
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//Re-allocate if the key is bigger than the capacity.
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if(keyLen > keyBuffer.capacity())
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{
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keyBuffer = ByteBuffer.allocate(keyLen);
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}
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keyBuffer.put(buffer, offSet, keyLen);
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keyBuffer.flip();
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return keyBuffer;
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}
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/**
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* Return the key value part of a record specified by the index.
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*
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* @param position position to return.
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* @return byte array containing the key value.
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*/
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private byte[] getKey(int position)
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{
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int offSet = getOffset(position) + REC_OVERHEAD + LONG_SIZE;
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int keyLen = readInt(buffer, offSet);
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offSet += INT_SIZE;
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byte[] key = new byte[keyLen];
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System.arraycopy(buffer, offSet, key, 0, keyLen);
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return key;
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}
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private int getOffset(int position)
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{
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return readInt(position * INT_SIZE);
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}
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/**
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* Return index id associated with the current position's record.
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*
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* @return The index id.
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*/
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public int getIndexID()
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{
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return getIndexID(position);
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}
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private int getIndexID(int position)
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{
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return getIndexIDFromOffset(getOffset(position));
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}
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private int getIndexIDFromOffset(int offset)
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{
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return readInt(offset + 1);
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}
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private int compare(int xPosition, int yPosition)
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{
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int xoffSet = getOffset(xPosition);
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int xIndexID = getIndexIDFromOffset(xoffSet);
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xoffSet += REC_OVERHEAD + LONG_SIZE;
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int xKeyLen = readInt(buffer, xoffSet);
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int xKey = INT_SIZE + xoffSet;
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int yoffSet = getOffset(yPosition);
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int yIndexID = getIndexIDFromOffset(yoffSet);
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yoffSet += REC_OVERHEAD + LONG_SIZE;
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int yKeyLen = readInt(buffer, yoffSet);
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int yKey = INT_SIZE + yoffSet;
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return indexComparator.compare(buffer, xKey, xKeyLen, xIndexID, buffer, yKey, yKeyLen, yIndexID);
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}
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private int compare(int xPosition, byte[] yKey, int yIndexID)
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{
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int xoffSet = getOffset(xPosition);
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int xIndexID = getIndexIDFromOffset(xoffSet);
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xoffSet += REC_OVERHEAD + LONG_SIZE;
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int xKeyLen = readInt(buffer, xoffSet);
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int xKey = INT_SIZE + xoffSet;
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return indexComparator.compare(buffer, xKey, xKeyLen, xIndexID, yKey, 0, yKey.length, yIndexID);
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}
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/**
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* Verifies whether the provided byte array and indexID are equal to
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* the byte array and indexIDs currently pointed to by this index output buffer.
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*
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* @param b The byte array to compare.
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* @param bIndexID The index key to compare.
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* @return <CODE>True</CODE> if the byte arrays are equal.
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*/
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public boolean recordsEqual(byte[] b, int bIndexID)
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{
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int offset = getOffset(position);
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int indexID = getIndexIDFromOffset(offset);
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offset += REC_OVERHEAD + LONG_SIZE;
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int keyLen = readInt(buffer, offset);
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int key = INT_SIZE + offset;
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return indexComparator.compare(buffer, key, keyLen, b, b.length) == 0
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&& indexID == bIndexID;
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}
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/**
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* Compare current IndexBuffer to the specified index buffer using both the
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* comparator and index ID of both buffers.
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*
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* The key at the value of position in both buffers are used in the compare.
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*
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* @param b The IndexBuffer to compare to.
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* @return 0 if the buffers are equal, -1 if the current buffer is less
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* than the specified buffer, or 1 if it is greater.
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*/
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@Override
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public int compareTo(IndexOutputBuffer b)
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{
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final ByteBuffer keyBuf = b.getKeyBuf(b.position);
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int offset = getOffset(position);
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int indexID = getIndexIDFromOffset(offset);
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offset += REC_OVERHEAD + LONG_SIZE;
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int keyLen = readInt(buffer, offset);
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int key = INT_SIZE + offset;
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int cmp = indexComparator.compare(buffer, key, keyLen, keyBuf.array(), keyBuf.limit());
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if (cmp == 0)
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{
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cmp = compareInts(indexID, b.getIndexID());
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if (cmp == 0)
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{
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// This is tested in a tree set remove when a buffer is removed from the tree set.
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return compareLongs(bufferID, b.getBufferID());
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}
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}
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return cmp;
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}
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private static int compareLongs(long l1, long l2)
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{
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if (l1 == l2)
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{
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return 0;
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}
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else if (l1 < l2)
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{
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return -1;
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}
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else
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{
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return 1;
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}
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}
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/**
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* Write a record to specified output stream using the record pointed to by
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* the current position and the specified byte stream of ids.
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*
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* @param dataStream The data output stream to write to.
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*
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* @throws IOException If an I/O error occurs writing the record.
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*/
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public void writeKey(DataOutputStream dataStream) throws IOException
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{
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int offSet = getOffset(position) + REC_OVERHEAD + LONG_SIZE;
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int keyLen = readInt(buffer, offSet);
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offSet += INT_SIZE;
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dataStream.write(buffer, offSet, keyLen);
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}
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/**
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* Compare the byte array at the current position with the byte array at the
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* provided position.
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*
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* @param position The index pointing to the byte array to compare.
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* @return {@code true} if the byte arrays are equal, or {@code false} otherwise
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*/
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public boolean byteArraysEqual(int position)
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{
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return compare(position, this.position) == 0;
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}
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/**
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* Return the current number of keys.
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*
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* @return The number of keys currently in an index buffer.
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*/
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public int getNumberKeys()
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{
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return keys;
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}
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/**
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* Return {@code true} if the buffer has more data to process, or
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* {@code false} otherwise. Used when iterating over the buffer writing the
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* scratch index file.
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*
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* @return {@code true} if a buffer has more data to process, or
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* {@code false} otherwise.
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*/
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public boolean hasMoreData()
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{
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return position + 1 < keys;
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}
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/**
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* Advance the position pointer to the next record in the buffer. Used when
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* iterating over the buffer examining keys.
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*/
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public void nextRecord()
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{
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position++;
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}
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private int writeInt(byte[] buffer, int offset, int val)
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{
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final int endOffset = offset + INT_SIZE;
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for (int i = endOffset - 1; i >= offset; i--) {
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buffer[i] = (byte) (val & 0xff);
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val >>>= 8;
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}
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return endOffset;
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}
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private int writeLong(byte[] buffer, int offset, long val)
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{
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final int endOffset = offset + LONG_SIZE;
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for (int i = endOffset - 1; i >= offset; i--) {
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buffer[i] = (byte) (val & 0xff);
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val >>>= 8;
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}
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return endOffset;
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}
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private int readInt(int index)
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{
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return readInt(buffer, index);
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}
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private int readInt(byte[] buffer, int index)
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{
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int answer = 0;
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for (int i = 0; i < INT_SIZE; i++) {
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byte b = buffer[index + i];
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answer <<= 8;
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answer |= (b & 0xff);
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}
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return answer;
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}
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private int med3(int a, int b, int c)
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{
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return compare(a,b) < 0
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? (compare(b,c) < 0 ? b : compare(a,c) < 0 ? c : a)
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: (compare(b,c) > 0 ? b : compare(a,c) > 0 ? c : a);
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}
|
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private void sort(int off, int len)
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{
|
if (len < 7) {
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for (int i=off; i<len+off; i++)
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{
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for (int j=i; j>off && compare(j-1, j)>0; j--)
|
{
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swap(j, j-1);
|
}
|
}
|
return;
|
}
|
|
int m = off + (len >> 1);
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if (len > 7) {
|
int l = off;
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int n = off + len - 1;
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if (len > 40) {
|
int s = len/8;
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l = med3(l, l+s, l+2*s);
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m = med3(m-s, m, m+s);
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n = med3(n-2*s, n-s, n);
|
}
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m = med3(l, m, n);
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}
|
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byte[] mKey = getKey(m);
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int mIndexID = getIndexID(m);
|
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int a = off, b = a, c = off + len - 1, d = c;
|
while(true)
|
{
|
while (b <= c && compare(b, mKey, mIndexID) <= 0)
|
{
|
if (compare(b, mKey, mIndexID) == 0)
|
{
|
swap(a++, b);
|
}
|
b++;
|
}
|
while (c >= b && compare(c, mKey, mIndexID) >= 0)
|
{
|
if (compare(c, mKey, mIndexID) == 0)
|
{
|
swap(c, d--);
|
}
|
c--;
|
}
|
if (b > c)
|
{
|
break;
|
}
|
swap(b++, c--);
|
}
|
|
// Swap partition elements back to middle
|
int s, n = off + len;
|
s = Math.min(a-off, b-a );
|
vectorSwap(off, b-s, s);
|
s = Math.min(d-c, n-d-1);
|
vectorSwap(b, n-s, s);
|
|
s = b - a;
|
// Recursively sort non-partition-elements
|
if (s > 1)
|
{
|
sort(off, s);
|
}
|
s = d - c;
|
if (s > 1)
|
{
|
sort(n-s, s);
|
}
|
}
|
|
private void swap(int a, int b)
|
{
|
int aOffset = a * INT_SIZE;
|
int bOffset = b * INT_SIZE;
|
int bVal = readInt(bOffset);
|
System.arraycopy(buffer, aOffset, buffer, bOffset, INT_SIZE);
|
writeInt(buffer, aOffset, bVal);
|
}
|
|
private void vectorSwap(int a, int b, int n)
|
{
|
for (int i=0; i<n; i++, a++, b++)
|
{
|
swap(a, b);
|
}
|
}
|
|
/**
|
* Used to compare keys when they are non-DN indexes.
|
* <p>
|
* The Comparator interface cannot be used in this class, so this
|
* special one is used that knows about the special properties of this class.
|
*/
|
public static class IndexComparator
|
{
|
|
/**
|
* Compare an offset in a byte array and indexID with the specified offset in the other byte array
|
* and other indexID, using the DN compare algorithm.
|
*
|
* @param array1 The first byte array.
|
* @param offset1 The first byte array's offset.
|
* @param length1 The first byte array's length.
|
* @param indexID1 The first index id.
|
* @param array2 The second byte array to compare to.
|
* @param offset1 The second byte array's offset.
|
* @param length2 The second byte array's length.
|
* @param indexID2 The second index id.
|
* @return a negative integer, zero, or a positive integer as the first
|
* offset value is less than, equal to, or greater than the second
|
* byte array.
|
*/
|
private int compare(byte[] array1, int offset1, int length1, int indexID1,
|
byte[] array2, int offset2, int length2, int indexID2)
|
{
|
int cmp = compareArrays(array1, offset1, length1, array2, offset2, length2);
|
if (cmp == 0)
|
{
|
cmp = compareInts(length1, length2);
|
if (cmp == 0)
|
{
|
return compareInts(indexID1, indexID2);
|
}
|
}
|
return cmp;
|
}
|
|
/**
|
* Compare an offset in an byte array with the specified byte array,
|
* using the DN compare algorithm.
|
*
|
* @param b The byte array.
|
* @param offset The first offset.
|
* @param length The first length.
|
* @param other The second byte array to compare to.
|
* @param otherLength The second byte array's length.
|
* @return a negative integer, zero, or a positive integer as the first
|
* offset value is less than, equal to, or greater than the second
|
* byte array.
|
*/
|
int compare(byte[] b, int offset, int length, byte[] other, int otherLength)
|
{
|
int cmp = compareArrays(b, offset, length, other, 0, otherLength);
|
if (cmp == 0)
|
{
|
return compareInts(length, otherLength);
|
}
|
return cmp;
|
}
|
|
private int compareArrays(byte[] array1, int offset1, int length1, byte[] array2, int offset2, int length2)
|
{
|
for (int i = 0; i < length1 && i < length2; i++)
|
{
|
byte b1 = array1[offset1 + i];
|
byte b2 = array2[offset2 + i];
|
if (b1 > b2)
|
{
|
return 1;
|
}
|
else if (b1 < b2)
|
{
|
return -1;
|
}
|
}
|
return 0;
|
}
|
}
|
|
private static int compareInts(int i1, int i2)
|
{
|
if (i1 == i2)
|
{
|
return 0;
|
}
|
else if (i1 > i2)
|
{
|
return 1;
|
}
|
else
|
{
|
return -1;
|
}
|
}
|
|
/**
|
* Set the index key associated with an index buffer.
|
*
|
* @param indexKey The index key.
|
*/
|
public void setIndexKey(Importer.IndexKey indexKey)
|
{
|
this.indexKey = indexKey;
|
}
|
|
|
/**
|
* Return the index key of an index buffer.
|
* @return The index buffer's index key.
|
*/
|
public Importer.IndexKey getIndexKey()
|
{
|
return indexKey;
|
}
|
}
|
