Storage.java revision 664be7d7d84b5c78001d984bd4ab51caa5273b80
/*
* 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.backends.pluggable.spi;
import java.io.Closeable;
import java.io.File;
import java.io.FilenameFilter;
/**
* This interface abstracts the underlying storage engine,
* isolating the pluggable backend generic code from a particular storage engine implementation.
*/
public interface Storage extends Closeable
{
/**
* Starts the import operation.
*
* @return a new Importer object which must be closed to release all resources
* @throws Exception
* if a problem occurs with the underlying storage engine
* @see #close() to release all resources once import is finished
*/
Importer startImport() throws Exception;
/**
* Opens the storage engine to allow executing operations on it.
*
* @throws Exception
* if a problem occurs with the underlying storage engine
* @see #close() to release all resources once import is finished
*/
void open() throws Exception;
/**
* Executes a read operation. In case of a read operation rollback, implementations must ensure
* the read operation is retried until it succeeds.
*
* @param <T>
* type of the value returned
* @param readOperation
* the read operation to execute
* @return the value read by the read operation
* @throws Exception
* if a problem occurs with the underlying storage engine
*/
<T> T read(ReadOperation<T> readOperation) throws Exception;
/**
* Executes a write operation. In case of a write operation rollback, implementations must ensure
* the write operation is retried until it succeeds.
*
* @param writeOperation
* the write operation to execute
* @throws Exception
* if a problem occurs with the underlying storage engine
*/
void write(WriteOperation writeOperation) throws Exception;
/**
* Returns a new writeable transaction.
*
* @return a new writeable transaction
*/
WriteableTransaction getWriteableTransaction();
/**
* Remove all files for a backend of this storage.
*
* @throws StorageRuntimeException if removal fails
*/
void removeStorageFiles() throws StorageRuntimeException;
/**
* Returns the current status of the storage.
*
* @return the current status of the storage
*/
StorageStatus getStorageStatus();
/**
* Returns {@code true} if this storage supports backup and restore.
*
* @return {@code true} if this storage supports backup and restore.
*/
boolean supportsBackupAndRestore();
/**
* Returns the file system directory in which any database files are located. This method is
* called when performing backup and restore operations.
*
* @return The file system directory in which any database files are located.
* @throws UnsupportedOperationException
* If backup and restore is not supported by this storage.
*/
File getDirectory();
/**
* Returns a filename filter which selects the files to be included in a backup. This method is
* called when performing backup operations.
*
* @return A filename filter which selects the files to be included in a backup.
* @throws UnsupportedOperationException
* If backup and restore is not supported by this storage.
*/
FilenameFilter getFilesToBackupFilter();
/** {@inheritDoc} */
@Override
void close();
}