/*
|
* 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 2014-2015 ForgeRock AS.
|
*/
|
package org.opends.server.replication.server.changelog.file;
|
|
import static org.opends.messages.ReplicationMessages.*;
|
|
import java.io.BufferedWriter;
|
import java.io.Closeable;
|
import java.io.File;
|
import java.io.FileWriter;
|
import java.io.IOException;
|
import java.io.RandomAccessFile;
|
|
import org.forgerock.i18n.LocalizableMessage;
|
import org.forgerock.i18n.slf4j.LocalizedLogger;
|
import org.forgerock.util.Pair;
|
import org.forgerock.util.Reject;
|
import org.opends.server.replication.server.changelog.api.ChangelogException;
|
import org.opends.server.replication.server.changelog.api.DBCursor;
|
import org.opends.server.replication.server.changelog.file.Log.RepositionableCursor;
|
import org.opends.server.util.StaticUtils;
|
|
/**
|
* A log file, containing part of a {@code Log}. The log file may be:
|
* <ul>
|
* <li>write-enabled : allowing to append key-value records and read records
|
* from cursors,</li>
|
* <li>read-only : allowing to read records from cursors.</li>
|
* </ul>
|
* <p>
|
* A log file is NOT intended to be used directly, but only has part of a
|
* {@link Log}. In particular, there is no concurrency management and no checks
|
* to ensure that log is not closed when performing any operation on it. Those
|
* are managed at the {@code Log} level.
|
*
|
* @param <K>
|
* Type of the key of a record, which must be comparable.
|
* @param <V>
|
* Type of the value of a record.
|
*/
|
final class LogFile<K extends Comparable<K>, V> implements Closeable
|
{
|
private static final LocalizedLogger logger = LocalizedLogger.getLoggerForThisClass();
|
|
/** The file containing the records. */
|
private final File logfile;
|
|
/** The pool to obtain a reader on the log. */
|
private final LogReaderPool<K, V> readerPool;
|
|
/**
|
* The writer on the log file, which may be {@code null} if log file is not
|
* write-enabled.
|
*/
|
private final BlockLogWriter<K, V> writer;
|
|
/** Indicates if log is enabled for write. */
|
private final boolean isWriteEnabled;
|
|
private Record<K, V> newestRecord;
|
|
/**
|
* Creates a new log file.
|
*
|
* @param logFilePath
|
* Path of the log file.
|
* @param parser
|
* Parser of records.
|
* @param isWriteEnabled
|
* {@code true} if this changelog is write-enabled, {@code false}
|
* otherwise.
|
* @throws ChangelogException
|
* If a problem occurs during initialization.
|
*/
|
private LogFile(final File logFilePath, final RecordParser<K, V> parser, boolean isWriteEnabled)
|
throws ChangelogException
|
{
|
Reject.ifNull(logFilePath, parser);
|
this.logfile = logFilePath;
|
this.isWriteEnabled = isWriteEnabled;
|
|
createLogFileIfNotExists();
|
if (isWriteEnabled)
|
{
|
ensureLogFileIsValid(parser);
|
writer = BlockLogWriter.newWriter(new LogWriter(logfile), parser);
|
}
|
else
|
{
|
writer = null;
|
}
|
readerPool = new LogReaderPool<>(logfile, parser);
|
}
|
|
/**
|
* Creates a read-only log file with the provided root path and record parser.
|
*
|
* @param <K>
|
* Type of the key of a record, which must be comparable.
|
* @param <V>
|
* Type of the value of a record.
|
* @param logFilePath
|
* Path of the log file.
|
* @param parser
|
* Parser of records.
|
* @return a read-only log file
|
* @throws ChangelogException
|
* If a problem occurs during initialization.
|
*/
|
static <K extends Comparable<K>, V> LogFile<K, V> newReadOnlyLogFile(final File logFilePath,
|
final RecordParser<K, V> parser) throws ChangelogException
|
{
|
return new LogFile<>(logFilePath, parser, false);
|
}
|
|
/**
|
* Creates a write-enabled log file that appends records to the end of file,
|
* with the provided root path and record parser.
|
*
|
* @param <K>
|
* Type of the key of a record, which must be comparable.
|
* @param <V>
|
* Type of the value of a record.
|
* @param logFilePath
|
* Path of the log file.
|
* @param parser
|
* Parser of records.
|
* @return a write-enabled log file
|
* @throws ChangelogException
|
* If a problem occurs during initialization.
|
*/
|
static <K extends Comparable<K>, V> LogFile<K, V> newAppendableLogFile(final File logFilePath,
|
final RecordParser<K, V> parser) throws ChangelogException
|
{
|
return new LogFile<>(logFilePath, parser, true);
|
}
|
|
/**
|
* Returns the file containing the records.
|
*
|
* @return the file
|
*/
|
File getFile()
|
{
|
return logfile;
|
}
|
|
private void checkLogIsEnabledForWrite() throws ChangelogException
|
{
|
if (!isWriteEnabled)
|
{
|
throw new ChangelogException(WARN_CHANGELOG_NOT_ENABLED_FOR_WRITE.get(logfile.getPath()));
|
}
|
}
|
|
private void createLogFileIfNotExists() throws ChangelogException
|
{
|
try
|
{
|
if (!logfile.exists())
|
{
|
logfile.createNewFile();
|
}
|
}
|
catch (IOException e)
|
{
|
throw new ChangelogException(ERR_CHANGELOG_UNABLE_TO_CREATE_LOG_FILE.get(logfile.getPath()), e);
|
}
|
}
|
|
/**
|
* Ensure that log file is not corrupted, by checking it is valid and cleaning
|
* the end of file if necessary, to remove a partially written record.
|
* <p>
|
* If log file is cleaned to remove a partially written record, then a message
|
* is logged for information.
|
*
|
* @throws ChangelogException
|
* If an error occurs or if log file is corrupted and can't be
|
* cleaned
|
*/
|
private void ensureLogFileIsValid(final RecordParser<K, V> parser) throws ChangelogException
|
{
|
try(final RandomAccessFile readerWriter = new RandomAccessFile(logfile, "rws");
|
final BlockLogReader<K, V> reader = BlockLogReader.newReader(logfile, readerWriter, parser))
|
{
|
final long lastValidPosition = reader.checkLogIsValid();
|
if (lastValidPosition != -1)
|
{
|
// truncate the file to point where last valid record has been read
|
readerWriter.setLength(lastValidPosition);
|
logger.error(INFO_CHANGELOG_LOG_FILE_RECOVERED.get(logfile.getPath()));
|
}
|
}
|
catch (IOException e)
|
{
|
throw new ChangelogException(ERR_CHANGELOG_UNABLE_TO_RECOVER_LOG_FILE.get(
|
logfile.getPath(),
|
StaticUtils.stackTraceToSingleLineString(e)));
|
}
|
}
|
|
/**
|
* Add the provided record at the end of this log.
|
* <p>
|
* In order to ensure that record is written out of buffers and persisted
|
* to file system, it is necessary to explicitely call the
|
* {@code syncToFileSystem()} method.
|
*
|
* @param record
|
* The record to add.
|
* @throws ChangelogException
|
* If the record can't be added to the log.
|
*/
|
void append(final Record<K, V> record) throws ChangelogException
|
{
|
checkLogIsEnabledForWrite();
|
writer.write(record);
|
newestRecord = record;
|
}
|
|
/**
|
* Dump this log file as a text file, intended for debugging purpose only.
|
*
|
* @param dumpFile
|
* File that will contains log records using a human-readable format
|
* @throws ChangelogException
|
* If an error occurs during dump
|
*/
|
void dumpAsTextFile(File dumpFile) throws ChangelogException
|
{
|
try(final BufferedWriter textWriter = new BufferedWriter(new FileWriter(dumpFile));
|
final DBCursor<Record<K, V>> cursor = getCursor())
|
{
|
while (cursor.getRecord() != null)
|
{
|
Record<K, V> record = cursor.getRecord();
|
textWriter.write("key=" + record.getKey());
|
textWriter.write(" | ");
|
textWriter.write("value=" + record.getValue());
|
textWriter.write('\n');
|
cursor.next();
|
}
|
}
|
catch (IOException e)
|
{
|
// No I18N needed, used for debugging purpose only
|
throw new ChangelogException(
|
LocalizableMessage.raw("Error when dumping content of log '%s' in target file : '%s'", getPath(), dumpFile),
|
e);
|
}
|
}
|
|
/**
|
* Synchronize all records added with the file system, ensuring that records
|
* are effectively persisted.
|
* <p>
|
* After a successful call to this method, it is guaranteed that all records
|
* added to the log are persisted to the file system.
|
*
|
* @throws ChangelogException
|
* If the synchronization fails.
|
*/
|
void syncToFileSystem() throws ChangelogException
|
{
|
checkLogIsEnabledForWrite();
|
try
|
{
|
writer.sync();
|
}
|
catch (Exception e)
|
{
|
throw new ChangelogException(ERR_CHANGELOG_UNABLE_TO_SYNC.get(getPath()), e);
|
}
|
}
|
|
/**
|
* Returns a cursor that allows to retrieve the records from this log,
|
* starting at the first position.
|
*
|
* @return a cursor on the log records, which is never {@code null}
|
* @throws ChangelogException
|
* If the cursor can't be created.
|
*/
|
LogFileCursor<K, V> getCursor() throws ChangelogException
|
{
|
return new LogFileCursor<>(this);
|
}
|
|
/**
|
* Returns a cursor initialized to the provided record and position in file.
|
*
|
* @param record
|
* The initial record this cursor points on
|
* @param position
|
* The file position this cursor points on
|
* @return the cursor
|
* @throws ChangelogException
|
* If a problem occurs while creating the cursor.
|
*/
|
LogFileCursor<K, V> getCursorInitialisedTo(Record<K,V> record, long position) throws ChangelogException
|
{
|
return new LogFileCursor<>(this, record, position);
|
}
|
|
/**
|
* Returns the oldest (first) record from this log.
|
*
|
* @return the oldest record, which may be {@code null} if there is no record
|
* in the log.
|
* @throws ChangelogException
|
* If an error occurs while retrieving the record.
|
*/
|
Record<K, V> getOldestRecord() throws ChangelogException
|
{
|
try (final DBCursor<Record<K, V>> cursor = getCursor())
|
{
|
return cursor.next() ? cursor.getRecord() : null;
|
}
|
}
|
|
/**
|
* Returns the newest (last) record from this log.
|
*
|
* @return the newest record, which may be {@code null}
|
* @throws ChangelogException
|
* If an error occurs while retrieving the record.
|
*/
|
Record<K, V> getNewestRecord() throws ChangelogException
|
{
|
if (newestRecord == null)
|
{
|
try (BlockLogReader<K, V> reader = getReader())
|
{
|
newestRecord = reader.getNewestRecord();
|
}
|
catch (IOException ioe)
|
{
|
throw new ChangelogException(ERR_CHANGELOG_CANNOT_READ_NEWEST_RECORD.get(logfile.getAbsolutePath()), ioe);
|
}
|
}
|
return newestRecord;
|
}
|
|
/**
|
* Returns the number of records in the log.
|
*
|
* @return the number of records
|
* @throws ChangelogException
|
* If an error occurs.
|
*/
|
long getNumberOfRecords() throws ChangelogException
|
{
|
// TODO : need a more efficient way to retrieve it
|
try(final DBCursor<Record<K, V>> cursor = getCursor())
|
{
|
long counter = 0L;
|
while (cursor.next())
|
{
|
counter++;
|
}
|
return counter;
|
}
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void close()
|
{
|
if (isWriteEnabled)
|
{
|
try
|
{
|
syncToFileSystem();
|
}
|
catch (ChangelogException e)
|
{
|
logger.traceException(e);
|
}
|
writer.close();
|
}
|
readerPool.shutdown();
|
}
|
|
/**
|
* Delete this log file (file is physically removed). Should be called only
|
* when log file is closed.
|
*
|
* @throws ChangelogException
|
* If log file can't be deleted.
|
*/
|
void delete() throws ChangelogException
|
{
|
if (!logfile.delete())
|
{
|
throw new ChangelogException(ERR_CHANGELOG_UNABLE_TO_DELETE_LOG_FILE.get(getPath()));
|
}
|
}
|
|
/**
|
* Return the size of this log file in bytes.
|
*
|
* @return the size of log file
|
*/
|
long getSizeInBytes()
|
{
|
return writer.getBytesWritten();
|
}
|
|
/** The path of this log file as a String. */
|
private String getPath()
|
{
|
return logfile.getPath();
|
}
|
|
/**
|
* Returns a reader for this log.
|
* <p>
|
* Assumes that calling methods ensure that log is not closed.
|
*/
|
private BlockLogReader<K, V> getReader() throws ChangelogException
|
{
|
return readerPool.get();
|
}
|
|
/** Release the provided reader. */
|
private void releaseReader(BlockLogReader<K, V> reader) {
|
readerPool.release(reader);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public int hashCode()
|
{
|
return logfile.hashCode();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public boolean equals(Object that)
|
{
|
if (this == that)
|
{
|
return true;
|
}
|
if (!(that instanceof LogFile))
|
{
|
return false;
|
}
|
final LogFile<?, ?> other = (LogFile<?, ?>) that;
|
return logfile.equals(other.logfile);
|
}
|
|
@Override
|
public String toString()
|
{
|
return "LogFile [logfile=" + logfile + ", isWriteEnabled=" + isWriteEnabled + "]";
|
}
|
|
/** Implements a repositionable cursor on the log file. */
|
static final class LogFileCursor<K extends Comparable<K>, V> implements RepositionableCursor<K,V>
|
{
|
/** The underlying log on which entries are read. */
|
private final LogFile<K, V> logFile;
|
|
/** To read the records. */
|
private final BlockLogReader<K, V> reader;
|
|
/** The current available record, may be {@code null}. */
|
private Record<K,V> currentRecord;
|
|
/**
|
* The initial record when starting from a given key. It must be
|
* stored because it is read in advance.
|
*/
|
private Record<K,V> initialRecord;
|
|
/**
|
* Creates a cursor on the provided log.
|
*
|
* @param logFile
|
* The log on which the cursor read records.
|
* @throws ChangelogException
|
* If an error occurs when creating the cursor.
|
*/
|
private LogFileCursor(final LogFile<K, V> logFile) throws ChangelogException
|
{
|
this.logFile = logFile;
|
this.reader = logFile.getReader();
|
}
|
|
/**
|
* Creates a cursor on the provided log, initialised to the provided record and
|
* pointing to the provided file position.
|
* <p>
|
* Note: there is no check to ensure that provided record and file position are
|
* consistent. It is the responsability of the caller of this method.
|
*/
|
private LogFileCursor(LogFile<K, V> logFile, Record<K, V> record, long filePosition) throws ChangelogException
|
{
|
this.logFile = logFile;
|
this.reader = logFile.getReader();
|
this.currentRecord = record;
|
reader.seekToPosition(filePosition);
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public boolean next() throws ChangelogException
|
{
|
if (initialRecord != null)
|
{
|
// initial record is used only once
|
currentRecord = initialRecord;
|
initialRecord = null;
|
return true;
|
}
|
currentRecord = reader.readRecord();
|
return currentRecord != null;
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public Record<K,V> getRecord()
|
{
|
return currentRecord;
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public boolean positionTo(final K key, final KeyMatchingStrategy match, final PositionStrategy pos)
|
throws ChangelogException {
|
final Pair<Boolean, Record<K, V>> result = reader.seekToRecord(key, match, pos);
|
final boolean found = result.getFirst();
|
initialRecord = found ? result.getSecond() : null;
|
return found;
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public void close()
|
{
|
logFile.releaseReader(reader);
|
}
|
|
/**
|
* Returns the file position this cursor is pointing at.
|
*
|
* @return the position of reader on the log file
|
* @throws ChangelogException
|
* If an error occurs.
|
*/
|
long getFilePosition() throws ChangelogException
|
{
|
return reader.getFilePosition();
|
}
|
|
/** {@inheritDoc} */
|
@Override
|
public String toString()
|
{
|
return String.format("Cursor on log file: %s, current record: %s", logFile.logfile, currentRecord);
|
}
|
}
|
}
|
