/*
* 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]
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* CDDL HEADER END
*
*
* Copyright 2014 ForgeRock AS.
*/
package org.opends.server.replication.server.changelog.file;
import java.io.File;
import java.io.RandomAccessFile;
import org.opends.server.replication.server.changelog.api.ChangelogException;
import org.opends.server.util.StaticUtils;
import static org.opends.messages.ReplicationMessages.*;
/**
* A Pool of readers to a log file.
*
* @param <K>
* Type of the key of a record, which must be comparable.
* @param <V>
* Type of the value of a record.
*/
// TODO : implement a real pool - reusing readers instead of opening-closing them each time
class LogReaderPool<K extends Comparable<K>, V>
{
/** The file to read. */
private final File file;
private final RecordParser<K, V> parser;
/**
* Creates a pool of readers for provided file.
*
* @param file
* The file to read.
* @param parser
* The parser to decode the records read.
*/
LogReaderPool(File file, RecordParser<K, V> parser)
{
this.file = file;
this.parser = parser;
}
/**
* Returns a random access reader on the provided file.
* <p>
* The acquired reader must be released with the {@code release()}
* method.
*
* @return a random access reader
* @throws ChangelogException
* If the file can't be found or read.
*/
BlockLogReader<K, V> get() throws ChangelogException
{
return getReader(file);
}
/**
* Release the provided reader.
* <p>
* Once released, this reader must not be used any more.
*
* @param reader
* The random access reader to a file previously acquired with this
* pool.
*/
void release(BlockLogReader<K, V> reader)
{
StaticUtils.close(reader);
}
/** Returns a random access file to read this log. */
private BlockLogReader<K, V> getReader(File file) throws ChangelogException
{
try
{
return BlockLogReader.newReader(file, new RandomAccessFile(file, "r"), parser) ;
}
catch (Exception e)
{
throw new ChangelogException(ERR_CHANGELOG_UNABLE_TO_OPEN_READER_ON_LOG_FILE.get(file.getPath()), e);
}
}
/**
* Shutdown this pool, releasing all files handles opened
* on the file.
*/
void shutdown()
{
// Nothing to do yet as no file handle is kept opened.
}
}