| /* |
| * 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.hadoop.hbase.replication; |
| import org.apache.hadoop.hbase.HBaseInterfaceAudience; |
| import org.apache.hadoop.hbase.wal.WAL.Entry; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * A Filter for WAL entries before being sent over to replication. Multiple |
| * filters might be chained together using {@link ChainWALEntryFilter}. |
| * Applied on the replication source side. |
| * <p>There is also a filter that can be installed on the sink end of a replication stream. |
| * See {@link org.apache.hadoop.hbase.replication.regionserver.WALEntrySinkFilter}. Certain |
| * use-cases may need such a facility but better to filter here on the source side rather |
| * than later, after the edit arrives at the sink.</p> |
| * @see org.apache.hadoop.hbase.replication.regionserver.WALEntrySinkFilter for filtering |
| * replication on the sink-side. |
| */ |
| @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.REPLICATION) |
| public interface WALEntryFilter { |
| /** |
| * <p> |
| * Applies the filter, possibly returning a different Entry instance. If null is returned, the |
| * entry will be skipped. |
| * </p> |
| * <p> |
| * Notice that you are free to modify the cell list of the give entry, but do not change the |
| * content of the cell, it may be used by others at the same time(and usually you can not modify a |
| * cell unless you cast it to the implementation class, which is not a good idea). |
| * </p> |
| * @param entry Entry to filter |
| * @return a (possibly modified) Entry to use. Returning null or an entry with no cells will cause |
| * the entry to be skipped for replication. |
| */ |
| Entry filter(Entry entry); |
| } |