/*
* Licensed to the Apache Software Foundation (ASF) under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional information regarding
* copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License. You may obtain a
* copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package org.apache.geode.cache.snapshot;
import java.io.File;
import java.io.IOException;
import org.apache.geode.DataSerializer;
import org.apache.geode.Instantiator;
import org.apache.geode.cache.Cache;
import org.apache.geode.cache.snapshot.SnapshotOptions.SnapshotFormat;
import org.apache.geode.pdx.PdxSerializer;
/**
* Allows a snapshot of cache data to be imported and exported. Each region in the cache will be
* included in the snapshot (one snapshot file for each region). Example usage:
*
* <pre>
* // obtain a snapshot
* CacheSnapshotService snapshot = cache.getSnapshotService();
*
* // export the snapshot, every region in the cache will be exported
* snapshot.save(new File("."), SnapshotFormat.GEMFIRE);
*
* // import the snapshot files, updates any existing entries in the cache
* snapshot.load(new File("."), SnapshotFormat.GEMFIRE);
* </pre>
*
* The default behavior is to perform all I/O operations on the node where the snapshot operations
* are invoked. This will involve either collecting or dispersing data over the network if the cache
* contains a partitioned region. The snapshot behavior can be changed using
* {@link SnapshotOptions}. For example:
*
* <pre>
* CacheSnapshotService snapshot = cache.getSnapshotService();
* SnapshotFilter filter = new SnapshotFilter() {
* public boolean accept(Entry<K, V> entry) {
* return true;
* }
* };
*
* SnapshotOptions<Object, Object> options = snapshot.createOptions();
* options.setFilter(filter);
*
* snapshot.save(new File("."), SnapshotFormat.GEMFIRE, options);
* </pre>
*
* Note that the snapshot does not provide a consistency guarantee. Updates to data during the
* course of import/export operations could result data inconsistencies.
*
* @see Cache#getSnapshotService()
* @see SnapshotOptions
*
* @since GemFire 7.0
*/
public interface CacheSnapshotService {
/**
* Creates a <code>SnapshotOptions</code> object configured with default settings. The options can
* be used to configure snapshot behavior.
*
* @return the default options
*/
SnapshotOptions<Object, Object> createOptions();
/**
* Exports all regions in the cache to the specified directory. The cache entries in each region
* will be written to a separate file.
*
* @param dir the directory for writing the snapshots, will be created if necessary
* @param format the snapshot format
*
* @throws IOException error writing snapshot
*/
void save(File dir, SnapshotFormat format) throws IOException;
/**
* Exports all regions in the cache to the specified directory by applying user-configured
* options. The cache entries in each region will be written to a separate file.
*
* @param dir the directory for writing the snapshots, will be created if necessary
* @param format the snapshot format
* @param options the snapshot options
*
* @throws IOException error writing snapshot
*/
void save(File dir, SnapshotFormat format, SnapshotOptions<Object, Object> options)
throws IOException;
/**
* Imports all files in the specified directory into the cache. The cache entries in a given
* snapshot file are loaded into the same region they were originally exported from (based on a
* corresponding region name). Files that do not match the supplied snapshot format will cause an
* import error.
* <p>
* Prior to loading data, all regions should have been created and any necessary serializers
* (either {@link DataSerializer} or {@link PdxSerializer}) and {@link Instantiator}s should have
* been registered.
*
* @param dir the directory containing the snapshot files
* @param format the snapshot file format
*
* @throws IOException Unable to import data
* @throws ClassNotFoundException Unable to import data
*/
void load(File dir, SnapshotFormat format) throws IOException, ClassNotFoundException;
/**
* Imports the specified files into the cache by applying user-configured options. The cache
* entries in a given snapshot file are loaded into the same region they were originally exported
* from (based on a corresponding region name). Files that do not match the supplied snapshot
* format will cause an import error.
* <p>
* Prior to loading data, all regions should have been created and any necessary serializers
* (either {@link DataSerializer} or {@link PdxSerializer}) and {@link Instantiator}s should have
* been registered.
*
* @param snapshots the snapshot files
* @param format the snapshot file format
* @param options the snapshot options
*
* @throws IOException Unable to import data
* @throws ClassNotFoundException Unable to import data
*/
void load(File[] snapshots, SnapshotFormat format, SnapshotOptions<Object, Object> options)
throws IOException, ClassNotFoundException;
}