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<pre><span class="sourceLineNo">001</span>/*<a name="line.1"></a>
<span class="sourceLineNo">002</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
<span class="sourceLineNo">003</span> * or more contributor license agreements. See the NOTICE file<a name="line.3"></a>
<span class="sourceLineNo">004</span> * distributed with this work for additional information<a name="line.4"></a>
<span class="sourceLineNo">005</span> * regarding copyright ownership. The ASF licenses this file<a name="line.5"></a>
<span class="sourceLineNo">006</span> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
<span class="sourceLineNo">007</span> * "License"); you may not use this file except in compliance<a name="line.7"></a>
<span class="sourceLineNo">008</span> * with the License. You may obtain a copy of the License at<a name="line.8"></a>
<span class="sourceLineNo">009</span> *<a name="line.9"></a>
<span class="sourceLineNo">010</span> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<span class="sourceLineNo">011</span> *<a name="line.11"></a>
<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
<span class="sourceLineNo">013</span> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
<span class="sourceLineNo">014</span> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
<span class="sourceLineNo">015</span> * See the License for the specific language governing permissions and<a name="line.15"></a>
<span class="sourceLineNo">016</span> * limitations under the License.<a name="line.16"></a>
<span class="sourceLineNo">017</span> */<a name="line.17"></a>
<span class="sourceLineNo">018</span>package org.apache.hadoop.hbase.replication;<a name="line.18"></a>
<span class="sourceLineNo">019</span>import org.apache.hadoop.hbase.HBaseInterfaceAudience;<a name="line.19"></a>
<span class="sourceLineNo">020</span>import org.apache.hadoop.hbase.wal.WAL.Entry;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.21"></a>
<span class="sourceLineNo">022</span><a name="line.22"></a>
<span class="sourceLineNo">023</span>/**<a name="line.23"></a>
<span class="sourceLineNo">024</span> * A Filter for WAL entries before being sent over to replication. Multiple<a name="line.24"></a>
<span class="sourceLineNo">025</span> * filters might be chained together using {@link ChainWALEntryFilter}.<a name="line.25"></a>
<span class="sourceLineNo">026</span> * Applied on the replication source side.<a name="line.26"></a>
<span class="sourceLineNo">027</span> * &lt;p&gt;There is also a filter that can be installed on the sink end of a replication stream.<a name="line.27"></a>
<span class="sourceLineNo">028</span> * See {@link org.apache.hadoop.hbase.replication.regionserver.WALEntrySinkFilter}. Certain<a name="line.28"></a>
<span class="sourceLineNo">029</span> * use-cases may need such a facility but better to filter here on the source side rather<a name="line.29"></a>
<span class="sourceLineNo">030</span> * than later, after the edit arrives at the sink.&lt;/p&gt;<a name="line.30"></a>
<span class="sourceLineNo">031</span> * @see org.apache.hadoop.hbase.replication.regionserver.WALEntrySinkFilter for filtering<a name="line.31"></a>
<span class="sourceLineNo">032</span> * replication on the sink-side.<a name="line.32"></a>
<span class="sourceLineNo">033</span> */<a name="line.33"></a>
<span class="sourceLineNo">034</span>@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.REPLICATION)<a name="line.34"></a>
<span class="sourceLineNo">035</span>public interface WALEntryFilter {<a name="line.35"></a>
<span class="sourceLineNo">036</span> /**<a name="line.36"></a>
<span class="sourceLineNo">037</span> * &lt;p&gt;<a name="line.37"></a>
<span class="sourceLineNo">038</span> * Applies the filter, possibly returning a different Entry instance. If null is returned, the<a name="line.38"></a>
<span class="sourceLineNo">039</span> * entry will be skipped.<a name="line.39"></a>
<span class="sourceLineNo">040</span> * &lt;/p&gt;<a name="line.40"></a>
<span class="sourceLineNo">041</span> * &lt;p&gt;<a name="line.41"></a>
<span class="sourceLineNo">042</span> * Notice that you are free to modify the cell list of the give entry, but do not change the<a name="line.42"></a>
<span class="sourceLineNo">043</span> * content of the cell, it may be used by others at the same time(and usually you can not modify a<a name="line.43"></a>
<span class="sourceLineNo">044</span> * cell unless you cast it to the implementation class, which is not a good idea).<a name="line.44"></a>
<span class="sourceLineNo">045</span> * &lt;/p&gt;<a name="line.45"></a>
<span class="sourceLineNo">046</span> * @param entry Entry to filter<a name="line.46"></a>
<span class="sourceLineNo">047</span> * @return a (possibly modified) Entry to use. Returning null or an entry with no cells will cause<a name="line.47"></a>
<span class="sourceLineNo">048</span> * the entry to be skipped for replication.<a name="line.48"></a>
<span class="sourceLineNo">049</span> */<a name="line.49"></a>
<span class="sourceLineNo">050</span> Entry filter(Entry entry);<a name="line.50"></a>
<span class="sourceLineNo">051</span>}<a name="line.51"></a>
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