/*
|
* CDDL HEADER START
|
*
|
* The contents of this file are subject to the terms of the
|
* Common Development and Distribution License, Version 1.0 only
|
* (the "License"). You may not use this file except in compliance
|
* with the License.
|
*
|
* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
|
* or http://forgerock.org/license/CDDLv1.0.html.
|
* See the License for the specific language governing permissions
|
* and limitations under the License.
|
*
|
* When distributing Covered Code, include this CDDL HEADER in each
|
* file and include the License file at legal-notices/CDDLv1_0.txt.
|
* If applicable, add the following below this CDDL HEADER, with the
|
* fields enclosed by brackets "[]" replaced with your own identifying
|
* information:
|
* Portions Copyright [yyyy] [name of copyright owner]
|
*
|
* CDDL HEADER END
|
*
|
*
|
* Copyright 2009-2010 Sun Microsystems, Inc.
|
* Portions Copyright 2013-2015 ForgeRock AS.
|
*/
|
package org.opends.server.backends.pluggable;
|
|
import static org.opends.server.backends.pluggable.ImportRecord.*;
|
import static org.opends.server.util.StaticUtils.*;
|
|
import java.io.ByteArrayOutputStream;
|
import java.util.Arrays;
|
import java.util.Comparator;
|
|
import org.forgerock.opendj.ldap.ByteSequence;
|
import org.opends.server.backends.pluggable.OnDiskMergeBufferImporter.IndexKey;
|
|
/**
|
* This class represents a index buffer used to store the keys and entry IDs
|
* processed from the LDIF file during phase one of an import, or rebuild index
|
* process. Each key and ID is stored in a record in the buffer.
|
* <p>
|
* The records in the buffer are eventually sorted, based on the key, when the
|
* maximum size of the buffer is reached and no more records will fit into the
|
* buffer. The buffer is scheduled to be flushed to an index scratch file and
|
* then re-cycled by the import, or rebuild-index process.
|
* </p>
|
* <p>
|
* The structure of a record in the buffer is the following:
|
*
|
* <pre>
|
* +-------------+-------------+---------+---------+------------+-----------+
|
* | record size | INS/DEL bit | indexID | entryID | key length | key bytes |
|
* +-------------+-------------+---------+---------+------------+-----------+
|
* </pre>
|
*
|
* The record size is used for fast seeks to quickly "jump" over records.
|
* </p>
|
* <p>
|
* The records are packed as much as possible, to optimize the buffer space.
|
* </p>
|
* <p>
|
* This class is not thread safe.
|
* </p>
|
*/
|
final class IndexOutputBuffer implements Comparable<IndexOutputBuffer> {
|
|
/** Buffer records are either insert records or delete records. */
|
private static final byte DEL = 0, INS = 1;
|
|
/** The size of a buffer. */
|
private final int size;
|
/** Byte array holding the actual buffer data. */
|
private final byte buffer[];
|
|
/**
|
* Used to break a tie (keys equal) when the buffers are being merged
|
* for writing to the index scratch file.
|
*/
|
private long bufferID;
|
|
/** OffSet where next key is written. */
|
private int keyOffset;
|
/** OffSet where next value record is written. */
|
private int recordOffset;
|
/** Amount of bytes left in the buffer. */
|
private int bytesLeft;
|
/** Number of keys in the buffer. */
|
private int keys;
|
/** Used to iterate over the buffer when writing to a scratch file. */
|
private int position;
|
|
/**
|
* Used to make sure that an instance of this class is put on the
|
* correct scratch file writer work queue for processing.
|
*/
|
private IndexKey indexKey;
|
|
/**
|
* Set to {@code true} if the buffer should not be recycled. Used when the
|
* importer/rebuild index process is doing phase one cleanup and flushing
|
* buffers not completed.
|
*/
|
private boolean discarded;
|
private ImportRecord currentRecord;
|
|
|
/**
|
* Create an instance of a IndexBuffer using the specified size.
|
*
|
* @param size The size of the underlying byte array.
|
*/
|
public IndexOutputBuffer(int size) {
|
this.size = size;
|
this.buffer = new byte[size];
|
this.bytesLeft = size;
|
this.recordOffset = size - 1;
|
}
|
|
|
/**
|
* Reset an IndexBuffer so it can be re-cycled.
|
*/
|
public void reset() {
|
bytesLeft = size;
|
keyOffset = 0;
|
recordOffset = size - 1;
|
keys = 0;
|
position = 0;
|
currentRecord = null;
|
indexKey = null;
|
}
|
|
/**
|
* Creates a new poison buffer. Poison buffers are used to stop the processing of import tasks.
|
*
|
* @return a new poison buffer
|
*/
|
public static IndexOutputBuffer poison()
|
{
|
return new IndexOutputBuffer(0);
|
}
|
|
/**
|
* Set the ID of a buffer to the specified value.
|
*
|
* @param bufferID The value to set the buffer ID to.
|
*/
|
public void setBufferID(long bufferID)
|
{
|
this.bufferID = bufferID;
|
}
|
|
/**
|
* Return the ID of a buffer.
|
*
|
* @return The value of a buffer's ID.
|
*/
|
private long getBufferID()
|
{
|
return this.bufferID;
|
}
|
|
/**
|
* Determines if a buffer is a poison buffer. A poison buffer is used to
|
* shutdown work queues when import/rebuild index phase one is completed.
|
* A poison buffer has a 0 size.
|
*
|
* @return {@code true} if a buffer is a poison buffer, or {@code false}
|
* otherwise.
|
*/
|
public boolean isPoison()
|
{
|
return size == 0;
|
}
|
|
/**
|
* Determines if buffer should be re-cycled by calling {@link #reset()}.
|
*
|
* @return {@code true} if buffer should be recycled, or {@code false} if it should not.
|
*/
|
boolean isDiscarded()
|
{
|
return discarded;
|
}
|
|
/**
|
* Sets the discarded flag to {@code true}.
|
*/
|
public void discard()
|
{
|
discarded = true;
|
}
|
|
/**
|
* Returns {@code true} if there is enough space available to write the
|
* specified byte array in the buffer. It returns {@code false} otherwise.
|
*
|
* @param kBytes The byte array to check space against.
|
* @param entryID The entryID value to check space against.
|
* @return {@code true} if there is space to write the byte array in a
|
* buffer, or {@code false} otherwise.
|
*/
|
public boolean isSpaceAvailable(ByteSequence kBytes, long entryID) {
|
return getRequiredSize(kBytes.length(), entryID) < bytesLeft;
|
}
|
|
/**
|
* Return a buffer's current position value.
|
*
|
* @return The buffer's current position value.
|
*/
|
public int getPosition()
|
{
|
return position;
|
}
|
|
/**
|
* Set a buffer's position value to the specified position.
|
*
|
* @param position The value to set the position to.
|
*/
|
public void setPosition(int position)
|
{
|
this.position = position;
|
this.currentRecord = toRecord(position);
|
}
|
|
/**
|
* Sort the buffer.
|
*/
|
public void sort()
|
{
|
Integer[] keyArray = new Integer[keys];
|
|
for (int i = 0; i < keys; i++)
|
{
|
keyArray[i] = readInt(i * INT_SIZE);
|
}
|
Arrays.sort(keyArray, new Comparator<Integer>()
|
{
|
public int compare(Integer i1, Integer i2)
|
{
|
return offsetToRecord(i1).compareTo(offsetToRecord(i2));
|
}
|
});
|
for (int i = 0; i < keys; i++)
|
{
|
writeInt(buffer, i * INT_SIZE, keyArray[i]);
|
}
|
}
|
|
/**
|
* Add the specified key byte array and EntryID to the buffer.
|
*
|
* @param keyBytes The key byte array.
|
* @param entryID The EntryID.
|
* @param indexID The index ID the record belongs.
|
* @param insert <CODE>True</CODE> if key is an insert, false otherwise.
|
*/
|
public void add(ByteSequence keyBytes, EntryID entryID, int indexID, boolean insert) {
|
// write the record data, but leave the space to write the record size just
|
// before it
|
recordOffset = addRecord(keyBytes, entryID.longValue(), indexID, insert);
|
// then write the returned record size
|
keyOffset = writeInt(buffer, keyOffset, recordOffset);
|
bytesLeft = recordOffset - keyOffset;
|
keys++;
|
}
|
|
|
/**
|
* Writes the full record minus the record size itself.
|
*/
|
private int addRecord(ByteSequence key, long entryID, int indexID, boolean insert)
|
{
|
int retOffset = recordOffset - getRecordSize(key.length());
|
int offSet = retOffset;
|
|
// write the INS/DEL bit
|
buffer[offSet++] = insert ? INS : DEL;
|
// write the indexID
|
offSet = writeInt(buffer, offSet, indexID);
|
// write the entryID
|
offSet = writeLong(buffer, offSet, entryID);
|
// write the key length
|
offSet = writeInt(buffer, offSet, key.length());
|
// write the key bytes
|
key.copyTo(buffer, offSet);
|
return retOffset;
|
}
|
|
|
/**
|
* Computes the full size of the record.
|
*
|
* @param keyLen The length of the key of index
|
* @param entryID The entry id
|
* @return The size that such record would take in the IndexOutputBuffer
|
*/
|
public static int getRequiredSize(int keyLen, long entryID)
|
{
|
// also add up the space needed to store the record size
|
return getRecordSize(keyLen) + INT_SIZE;
|
}
|
|
private static int getRecordSize(int keyLen)
|
{
|
// Adds up (INS/DEL bit + indexID) + entryID + key length + key bytes
|
return REC_OVERHEAD + LONG_SIZE + INT_SIZE + keyLen;
|
}
|
|
/**
|
* Write the entryID at the specified position to the specified output stream.
|
* Used when writing the index scratch files.
|
*
|
* @param stream The stream to write the record at the index to.
|
* @param position The position of the record to write.
|
*/
|
public void writeEntryID(ByteArrayOutputStream stream, int position)
|
{
|
int offSet = getOffset(position);
|
stream.write(buffer, offSet + REC_OVERHEAD, LONG_SIZE);
|
}
|
|
|
/**
|
* Return {@code true} if the record specified by the position is an insert
|
* record, or {@code false} if it a delete record.
|
*
|
* @param position The position of the record.
|
* @return {@code true} if the record is an insert record, or {@code false}
|
* if it is a delete record.
|
*/
|
public boolean isInsertRecord(int position)
|
{
|
int recOffset = getOffset(position);
|
return buffer[recOffset] == INS;
|
}
|
|
private int getOffset(int position)
|
{
|
return readInt(position * INT_SIZE);
|
}
|
|
private ImportRecord offsetToRecord(int offset)
|
{
|
return ImportRecord.fromBufferAndOffset(buffer, offset);
|
}
|
|
private ImportRecord toRecord(int position)
|
{
|
return ImportRecord.fromBufferAndPosition(buffer, position);
|
}
|
|
ImportRecord currentRecord()
|
{
|
return currentRecord;
|
}
|
|
/**
|
* Compare current IndexBuffer to the specified index buffer using both the
|
* comparator and index ID of both buffers.
|
*
|
* The key at the value of position in both buffers are used in the compare.
|
*
|
* @param b The IndexBuffer to compare to.
|
* @return 0 if the buffers are equal, -1 if the current buffer is less
|
* than the specified buffer, or 1 if it is greater.
|
*/
|
@Override
|
public int compareTo(IndexOutputBuffer b)
|
{
|
int cmp = currentRecord().compareTo(b.currentRecord());
|
if (cmp == 0)
|
{
|
// This is tested in a tree set remove when a buffer is removed from the tree set.
|
return compareLongs(bufferID, b.getBufferID());
|
}
|
return cmp;
|
}
|
|
private static int compareLongs(long l1, long l2)
|
{
|
if (l1 == l2)
|
{
|
return 0;
|
}
|
else if (l1 < l2)
|
{
|
return -1;
|
}
|
else
|
{
|
return 1;
|
}
|
}
|
|
/**
|
* Compare the byte array at the current position with the byte array at the
|
* provided position.
|
*
|
* @param position The index pointing to the byte array to compare.
|
* @return {@code true} if the byte arrays are equal, or {@code false} otherwise
|
*/
|
public boolean sameKeyAndIndexID(int position)
|
{
|
return currentRecord().equals(toRecord(position));
|
}
|
|
/**
|
* Return the current number of keys.
|
*
|
* @return The number of keys currently in an index buffer.
|
*/
|
public int getNumberKeys()
|
{
|
return keys;
|
}
|
|
/**
|
* Return {@code true} if the buffer has more data to process, or
|
* {@code false} otherwise. Used when iterating over the buffer writing the
|
* scratch index file.
|
*
|
* @return {@code true} if a buffer has more data to process, or
|
* {@code false} otherwise.
|
*/
|
public boolean hasMoreData()
|
{
|
return position + 1 < keys;
|
}
|
|
/**
|
* Advance the position pointer to the next record in the buffer. Used when
|
* iterating over the buffer examining keys.
|
*/
|
public void nextRecord()
|
{
|
setPosition(position + 1);
|
}
|
|
private int writeInt(byte[] buffer, int offset, int val)
|
{
|
final int endOffset = offset + INT_SIZE;
|
for (int i = endOffset - 1; i >= offset; i--) {
|
buffer[i] = (byte) (val & 0xff);
|
val >>>= 8;
|
}
|
return endOffset;
|
}
|
|
private int writeLong(byte[] buffer, int offset, long val)
|
{
|
final int endOffset = offset + LONG_SIZE;
|
for (int i = endOffset - 1; i >= offset; i--) {
|
buffer[i] = (byte) (val & 0xff);
|
val >>>= 8;
|
}
|
return endOffset;
|
}
|
|
private int readInt(int index)
|
{
|
int answer = 0;
|
for (int i = 0; i < INT_SIZE; i++) {
|
byte b = buffer[index + i];
|
answer <<= 8;
|
answer |= b & 0xff;
|
}
|
return answer;
|
}
|
|
/**
|
* Set the index key associated with an index buffer.
|
*
|
* @param indexKey The index key.
|
*/
|
public void setIndexKey(IndexKey indexKey)
|
{
|
this.indexKey = indexKey;
|
}
|
|
/**
|
* Return the index key of an index buffer.
|
* @return The index buffer's index key.
|
*/
|
public IndexKey getIndexKey()
|
{
|
return indexKey;
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public String toString()
|
{
|
return getClass().getSimpleName() + "("
|
+ "bufferID=" + bufferID + ", " + currentRecord + ", indexKey=" + indexKey
|
+ ")";
|
}
|
}
|
