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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><a name="line.18"></a>
<span class="sourceLineNo">019</span>package org.apache.hadoop.hbase.procedure2.util;<a name="line.19"></a>
<span class="sourceLineNo">020</span><a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.io.IOException;<a name="line.21"></a>
<span class="sourceLineNo">022</span>import java.io.OutputStream;<a name="line.22"></a>
<span class="sourceLineNo">023</span>import java.util.Arrays;<a name="line.23"></a>
<span class="sourceLineNo">024</span><a name="line.24"></a>
<span class="sourceLineNo">025</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import org.apache.yetus.audience.InterfaceStability;<a name="line.26"></a>
<span class="sourceLineNo">027</span><a name="line.27"></a>
<span class="sourceLineNo">028</span>/**<a name="line.28"></a>
<span class="sourceLineNo">029</span> * Similar to the ByteArrayOutputStream, with the exception that we can prepend an header.<a name="line.29"></a>
<span class="sourceLineNo">030</span> * e.g. you write some data and you want to prepend an header that contains the data len or cksum.<a name="line.30"></a>
<span class="sourceLineNo">031</span> * &lt;code&gt;<a name="line.31"></a>
<span class="sourceLineNo">032</span> * ByteSlot slot = new ByteSlot();<a name="line.32"></a>
<span class="sourceLineNo">033</span> * // write data<a name="line.33"></a>
<span class="sourceLineNo">034</span> * slot.write(...);<a name="line.34"></a>
<span class="sourceLineNo">035</span> * slot.write(...);<a name="line.35"></a>
<span class="sourceLineNo">036</span> * // write header with the size of the written data<a name="line.36"></a>
<span class="sourceLineNo">037</span> * slot.markHead();<a name="line.37"></a>
<span class="sourceLineNo">038</span> * slot.write(Bytes.toBytes(slot.size()));<a name="line.38"></a>
<span class="sourceLineNo">039</span> * // flush to stream as [header, data]<a name="line.39"></a>
<span class="sourceLineNo">040</span> * slot.writeTo(stream);<a name="line.40"></a>
<span class="sourceLineNo">041</span> * &lt;/code&gt;<a name="line.41"></a>
<span class="sourceLineNo">042</span> */<a name="line.42"></a>
<span class="sourceLineNo">043</span>@InterfaceAudience.Private<a name="line.43"></a>
<span class="sourceLineNo">044</span>@InterfaceStability.Evolving<a name="line.44"></a>
<span class="sourceLineNo">045</span>public class ByteSlot extends OutputStream {<a name="line.45"></a>
<span class="sourceLineNo">046</span> private static final int LARGE_GROW_SIZE_THRESHOLD = 8 &lt;&lt; 20;<a name="line.46"></a>
<span class="sourceLineNo">047</span> private static final int LARGE_GROW_SIZE = 1 &lt;&lt; 20;<a name="line.47"></a>
<span class="sourceLineNo">048</span> private static final int RESET_THRESHOLD = 64 &lt;&lt; 20;<a name="line.48"></a>
<span class="sourceLineNo">049</span> private static final int GROW_ALIGN = 128;<a name="line.49"></a>
<span class="sourceLineNo">050</span><a name="line.50"></a>
<span class="sourceLineNo">051</span> private byte[] buf;<a name="line.51"></a>
<span class="sourceLineNo">052</span> private int head;<a name="line.52"></a>
<span class="sourceLineNo">053</span> private int size;<a name="line.53"></a>
<span class="sourceLineNo">054</span><a name="line.54"></a>
<span class="sourceLineNo">055</span> public void reset() {<a name="line.55"></a>
<span class="sourceLineNo">056</span> if (buf != null &amp;&amp; buf.length &gt; RESET_THRESHOLD) {<a name="line.56"></a>
<span class="sourceLineNo">057</span> buf = null;<a name="line.57"></a>
<span class="sourceLineNo">058</span> }<a name="line.58"></a>
<span class="sourceLineNo">059</span> head = 0;<a name="line.59"></a>
<span class="sourceLineNo">060</span> size = 0;<a name="line.60"></a>
<span class="sourceLineNo">061</span> }<a name="line.61"></a>
<span class="sourceLineNo">062</span><a name="line.62"></a>
<span class="sourceLineNo">063</span> public void markHead() {<a name="line.63"></a>
<span class="sourceLineNo">064</span> head = size;<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> public int getHead() {<a name="line.67"></a>
<span class="sourceLineNo">068</span> return head;<a name="line.68"></a>
<span class="sourceLineNo">069</span> }<a name="line.69"></a>
<span class="sourceLineNo">070</span><a name="line.70"></a>
<span class="sourceLineNo">071</span> public int size() {<a name="line.71"></a>
<span class="sourceLineNo">072</span> return size;<a name="line.72"></a>
<span class="sourceLineNo">073</span> }<a name="line.73"></a>
<span class="sourceLineNo">074</span><a name="line.74"></a>
<span class="sourceLineNo">075</span> public byte[] getBuffer() {<a name="line.75"></a>
<span class="sourceLineNo">076</span> return buf;<a name="line.76"></a>
<span class="sourceLineNo">077</span> }<a name="line.77"></a>
<span class="sourceLineNo">078</span><a name="line.78"></a>
<span class="sourceLineNo">079</span> public void writeAt(int offset, int b) {<a name="line.79"></a>
<span class="sourceLineNo">080</span> head = Math.min(head, offset);<a name="line.80"></a>
<span class="sourceLineNo">081</span> buf[offset] = (byte)b;<a name="line.81"></a>
<span class="sourceLineNo">082</span> }<a name="line.82"></a>
<span class="sourceLineNo">083</span><a name="line.83"></a>
<span class="sourceLineNo">084</span> @Override<a name="line.84"></a>
<span class="sourceLineNo">085</span> public void write(int b) {<a name="line.85"></a>
<span class="sourceLineNo">086</span> ensureCapacity(size + 1);<a name="line.86"></a>
<span class="sourceLineNo">087</span> buf[size++] = (byte)b;<a name="line.87"></a>
<span class="sourceLineNo">088</span> }<a name="line.88"></a>
<span class="sourceLineNo">089</span><a name="line.89"></a>
<span class="sourceLineNo">090</span> @Override<a name="line.90"></a>
<span class="sourceLineNo">091</span> public void write(byte[] b, int off, int len) {<a name="line.91"></a>
<span class="sourceLineNo">092</span> ensureCapacity(size + len);<a name="line.92"></a>
<span class="sourceLineNo">093</span> System.arraycopy(b, off, buf, size, len);<a name="line.93"></a>
<span class="sourceLineNo">094</span> size += len;<a name="line.94"></a>
<span class="sourceLineNo">095</span> }<a name="line.95"></a>
<span class="sourceLineNo">096</span><a name="line.96"></a>
<span class="sourceLineNo">097</span> public void writeTo(final OutputStream stream) throws IOException {<a name="line.97"></a>
<span class="sourceLineNo">098</span> if (head != 0) {<a name="line.98"></a>
<span class="sourceLineNo">099</span> stream.write(buf, head, size - head);<a name="line.99"></a>
<span class="sourceLineNo">100</span> stream.write(buf, 0, head);<a name="line.100"></a>
<span class="sourceLineNo">101</span> } else {<a name="line.101"></a>
<span class="sourceLineNo">102</span> stream.write(buf, 0, size);<a name="line.102"></a>
<span class="sourceLineNo">103</span> }<a name="line.103"></a>
<span class="sourceLineNo">104</span> }<a name="line.104"></a>
<span class="sourceLineNo">105</span><a name="line.105"></a>
<span class="sourceLineNo">106</span> private void ensureCapacity(int minCapacity) {<a name="line.106"></a>
<span class="sourceLineNo">107</span> minCapacity = (minCapacity + (GROW_ALIGN - 1)) &amp; -GROW_ALIGN;<a name="line.107"></a>
<span class="sourceLineNo">108</span> if (buf == null) {<a name="line.108"></a>
<span class="sourceLineNo">109</span> buf = new byte[minCapacity];<a name="line.109"></a>
<span class="sourceLineNo">110</span> } else if (minCapacity &gt; buf.length) {<a name="line.110"></a>
<span class="sourceLineNo">111</span> int newCapacity;<a name="line.111"></a>
<span class="sourceLineNo">112</span> if (buf.length &lt;= LARGE_GROW_SIZE_THRESHOLD) {<a name="line.112"></a>
<span class="sourceLineNo">113</span> newCapacity = buf.length &lt;&lt; 1;<a name="line.113"></a>
<span class="sourceLineNo">114</span> } else {<a name="line.114"></a>
<span class="sourceLineNo">115</span> newCapacity = buf.length + LARGE_GROW_SIZE;<a name="line.115"></a>
<span class="sourceLineNo">116</span> }<a name="line.116"></a>
<span class="sourceLineNo">117</span> if (minCapacity &gt; newCapacity) {<a name="line.117"></a>
<span class="sourceLineNo">118</span> newCapacity = minCapacity;<a name="line.118"></a>
<span class="sourceLineNo">119</span> }<a name="line.119"></a>
<span class="sourceLineNo">120</span> buf = Arrays.copyOf(buf, newCapacity);<a name="line.120"></a>
<span class="sourceLineNo">121</span> }<a name="line.121"></a>
<span class="sourceLineNo">122</span> }<a name="line.122"></a>
<span class="sourceLineNo">123</span>}<a name="line.123"></a>
</pre>
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