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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.ipc;<a name="line.18"></a>
<span class="sourceLineNo">019</span><a name="line.19"></a>
<span class="sourceLineNo">020</span>import java.io.IOException;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.nio.ByteBuffer;<a name="line.21"></a>
<span class="sourceLineNo">022</span>import java.nio.channels.GatheringByteChannel;<a name="line.22"></a>
<span class="sourceLineNo">023</span><a name="line.23"></a>
<span class="sourceLineNo">024</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.24"></a>
<span class="sourceLineNo">025</span><a name="line.25"></a>
<span class="sourceLineNo">026</span>/**<a name="line.26"></a>
<span class="sourceLineNo">027</span> * Chain of ByteBuffers.<a name="line.27"></a>
<span class="sourceLineNo">028</span> * Used writing out an array of byte buffers. Writes in chunks.<a name="line.28"></a>
<span class="sourceLineNo">029</span> */<a name="line.29"></a>
<span class="sourceLineNo">030</span>@InterfaceAudience.Private<a name="line.30"></a>
<span class="sourceLineNo">031</span>class BufferChain {<a name="line.31"></a>
<span class="sourceLineNo">032</span> private final ByteBuffer[] buffers;<a name="line.32"></a>
<span class="sourceLineNo">033</span> private int remaining = 0;<a name="line.33"></a>
<span class="sourceLineNo">034</span> private int bufferOffset = 0;<a name="line.34"></a>
<span class="sourceLineNo">035</span> private int size;<a name="line.35"></a>
<span class="sourceLineNo">036</span><a name="line.36"></a>
<span class="sourceLineNo">037</span> BufferChain(ByteBuffer... buffers) {<a name="line.37"></a>
<span class="sourceLineNo">038</span> for (ByteBuffer b : buffers) {<a name="line.38"></a>
<span class="sourceLineNo">039</span> this.remaining += b.remaining();<a name="line.39"></a>
<span class="sourceLineNo">040</span> }<a name="line.40"></a>
<span class="sourceLineNo">041</span> this.size = remaining;<a name="line.41"></a>
<span class="sourceLineNo">042</span> this.buffers = buffers;<a name="line.42"></a>
<span class="sourceLineNo">043</span> }<a name="line.43"></a>
<span class="sourceLineNo">044</span><a name="line.44"></a>
<span class="sourceLineNo">045</span> /**<a name="line.45"></a>
<span class="sourceLineNo">046</span> * Expensive. Makes a new buffer to hold a copy of what is in contained ByteBuffers. This<a name="line.46"></a>
<span class="sourceLineNo">047</span> * call drains this instance; it cannot be used subsequent to the call.<a name="line.47"></a>
<span class="sourceLineNo">048</span> * @return A new byte buffer with the content of all contained ByteBuffers.<a name="line.48"></a>
<span class="sourceLineNo">049</span> */<a name="line.49"></a>
<span class="sourceLineNo">050</span> byte [] getBytes() {<a name="line.50"></a>
<span class="sourceLineNo">051</span> if (!hasRemaining()) throw new IllegalAccessError();<a name="line.51"></a>
<span class="sourceLineNo">052</span> byte [] bytes = new byte [this.remaining];<a name="line.52"></a>
<span class="sourceLineNo">053</span> int offset = 0;<a name="line.53"></a>
<span class="sourceLineNo">054</span> for (ByteBuffer bb: this.buffers) {<a name="line.54"></a>
<span class="sourceLineNo">055</span> int length = bb.remaining();<a name="line.55"></a>
<span class="sourceLineNo">056</span> bb.get(bytes, offset, length);<a name="line.56"></a>
<span class="sourceLineNo">057</span> offset += length;<a name="line.57"></a>
<span class="sourceLineNo">058</span> }<a name="line.58"></a>
<span class="sourceLineNo">059</span> return bytes;<a name="line.59"></a>
<span class="sourceLineNo">060</span> }<a name="line.60"></a>
<span class="sourceLineNo">061</span><a name="line.61"></a>
<span class="sourceLineNo">062</span> boolean hasRemaining() {<a name="line.62"></a>
<span class="sourceLineNo">063</span> return remaining &gt; 0;<a name="line.63"></a>
<span class="sourceLineNo">064</span> }<a name="line.64"></a>
<span class="sourceLineNo">065</span><a name="line.65"></a>
<span class="sourceLineNo">066</span> /**<a name="line.66"></a>
<span class="sourceLineNo">067</span> * Write out our chain of buffers in chunks<a name="line.67"></a>
<span class="sourceLineNo">068</span> * @param channel Where to write<a name="line.68"></a>
<span class="sourceLineNo">069</span> * @param chunkSize Size of chunks to write.<a name="line.69"></a>
<span class="sourceLineNo">070</span> * @return Amount written.<a name="line.70"></a>
<span class="sourceLineNo">071</span> * @throws IOException<a name="line.71"></a>
<span class="sourceLineNo">072</span> */<a name="line.72"></a>
<span class="sourceLineNo">073</span> long write(GatheringByteChannel channel, int chunkSize) throws IOException {<a name="line.73"></a>
<span class="sourceLineNo">074</span> int chunkRemaining = chunkSize;<a name="line.74"></a>
<span class="sourceLineNo">075</span> ByteBuffer lastBuffer = null;<a name="line.75"></a>
<span class="sourceLineNo">076</span> int bufCount = 0;<a name="line.76"></a>
<span class="sourceLineNo">077</span> int restoreLimit = -1;<a name="line.77"></a>
<span class="sourceLineNo">078</span><a name="line.78"></a>
<span class="sourceLineNo">079</span> while (chunkRemaining &gt; 0 &amp;&amp; bufferOffset + bufCount &lt; buffers.length) {<a name="line.79"></a>
<span class="sourceLineNo">080</span> lastBuffer = buffers[bufferOffset + bufCount];<a name="line.80"></a>
<span class="sourceLineNo">081</span> if (!lastBuffer.hasRemaining()) {<a name="line.81"></a>
<span class="sourceLineNo">082</span> bufferOffset++;<a name="line.82"></a>
<span class="sourceLineNo">083</span> continue;<a name="line.83"></a>
<span class="sourceLineNo">084</span> }<a name="line.84"></a>
<span class="sourceLineNo">085</span> bufCount++;<a name="line.85"></a>
<span class="sourceLineNo">086</span> if (lastBuffer.remaining() &gt; chunkRemaining) {<a name="line.86"></a>
<span class="sourceLineNo">087</span> restoreLimit = lastBuffer.limit();<a name="line.87"></a>
<span class="sourceLineNo">088</span> lastBuffer.limit(lastBuffer.position() + chunkRemaining);<a name="line.88"></a>
<span class="sourceLineNo">089</span> chunkRemaining = 0;<a name="line.89"></a>
<span class="sourceLineNo">090</span> break;<a name="line.90"></a>
<span class="sourceLineNo">091</span> } else {<a name="line.91"></a>
<span class="sourceLineNo">092</span> chunkRemaining -= lastBuffer.remaining();<a name="line.92"></a>
<span class="sourceLineNo">093</span> }<a name="line.93"></a>
<span class="sourceLineNo">094</span> }<a name="line.94"></a>
<span class="sourceLineNo">095</span> assert lastBuffer != null;<a name="line.95"></a>
<span class="sourceLineNo">096</span> if (chunkRemaining == chunkSize) {<a name="line.96"></a>
<span class="sourceLineNo">097</span> assert !hasRemaining();<a name="line.97"></a>
<span class="sourceLineNo">098</span> // no data left to write<a name="line.98"></a>
<span class="sourceLineNo">099</span> return 0;<a name="line.99"></a>
<span class="sourceLineNo">100</span> }<a name="line.100"></a>
<span class="sourceLineNo">101</span> try {<a name="line.101"></a>
<span class="sourceLineNo">102</span> long ret = channel.write(buffers, bufferOffset, bufCount);<a name="line.102"></a>
<span class="sourceLineNo">103</span> if (ret &gt; 0) {<a name="line.103"></a>
<span class="sourceLineNo">104</span> remaining = (int) (remaining - ret);<a name="line.104"></a>
<span class="sourceLineNo">105</span> }<a name="line.105"></a>
<span class="sourceLineNo">106</span> return ret;<a name="line.106"></a>
<span class="sourceLineNo">107</span> } finally {<a name="line.107"></a>
<span class="sourceLineNo">108</span> if (restoreLimit &gt;= 0) {<a name="line.108"></a>
<span class="sourceLineNo">109</span> lastBuffer.limit(restoreLimit);<a name="line.109"></a>
<span class="sourceLineNo">110</span> }<a name="line.110"></a>
<span class="sourceLineNo">111</span> }<a name="line.111"></a>
<span class="sourceLineNo">112</span> }<a name="line.112"></a>
<span class="sourceLineNo">113</span><a name="line.113"></a>
<span class="sourceLineNo">114</span> int size() {<a name="line.114"></a>
<span class="sourceLineNo">115</span> return size;<a name="line.115"></a>
<span class="sourceLineNo">116</span> }<a name="line.116"></a>
<span class="sourceLineNo">117</span><a name="line.117"></a>
<span class="sourceLineNo">118</span> ByteBuffer[] getBuffers() {<a name="line.118"></a>
<span class="sourceLineNo">119</span> return this.buffers;<a name="line.119"></a>
<span class="sourceLineNo">120</span> }<a name="line.120"></a>
<span class="sourceLineNo">121</span>}<a name="line.121"></a>
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