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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.client;<a name="line.18"></a>
<span class="sourceLineNo">019</span><a name="line.19"></a>
<span class="sourceLineNo">020</span>import static org.apache.hadoop.hbase.client.ConnectionUtils.calcEstimatedSize;<a name="line.20"></a>
<span class="sourceLineNo">021</span><a name="line.21"></a>
<span class="sourceLineNo">022</span>import io.opentelemetry.api.trace.Span;<a name="line.22"></a>
<span class="sourceLineNo">023</span>import java.io.IOException;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import java.io.InterruptedIOException;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import java.util.ArrayDeque;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import java.util.Queue;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import org.apache.hadoop.hbase.TableName;<a name="line.27"></a>
<span class="sourceLineNo">028</span>import org.apache.hadoop.hbase.client.metrics.ScanMetrics;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import org.apache.hadoop.hbase.util.FutureUtils;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.30"></a>
<span class="sourceLineNo">031</span>import org.slf4j.Logger;<a name="line.31"></a>
<span class="sourceLineNo">032</span>import org.slf4j.LoggerFactory;<a name="line.32"></a>
<span class="sourceLineNo">033</span><a name="line.33"></a>
<span class="sourceLineNo">034</span>/**<a name="line.34"></a>
<span class="sourceLineNo">035</span> * The {@link ResultScanner} implementation for {@link RawAsyncTableImpl}. It will fetch data<a name="line.35"></a>
<span class="sourceLineNo">036</span> * automatically in background and cache it in memory. Typically, the {@link #maxCacheSize} will be<a name="line.36"></a>
<span class="sourceLineNo">037</span> * {@code 2 * scan.getMaxResultSize()}.<a name="line.37"></a>
<span class="sourceLineNo">038</span> */<a name="line.38"></a>
<span class="sourceLineNo">039</span>@InterfaceAudience.Private<a name="line.39"></a>
<span class="sourceLineNo">040</span>class AsyncTableResultScanner implements ResultScanner, AdvancedScanResultConsumer {<a name="line.40"></a>
<span class="sourceLineNo">041</span><a name="line.41"></a>
<span class="sourceLineNo">042</span> private static final Logger LOG = LoggerFactory.getLogger(AsyncTableResultScanner.class);<a name="line.42"></a>
<span class="sourceLineNo">043</span><a name="line.43"></a>
<span class="sourceLineNo">044</span> private final TableName tableName;<a name="line.44"></a>
<span class="sourceLineNo">045</span><a name="line.45"></a>
<span class="sourceLineNo">046</span> private final long maxCacheSize;<a name="line.46"></a>
<span class="sourceLineNo">047</span><a name="line.47"></a>
<span class="sourceLineNo">048</span> private final Scan scan;<a name="line.48"></a>
<span class="sourceLineNo">049</span><a name="line.49"></a>
<span class="sourceLineNo">050</span> private final Queue&lt;Result&gt; queue = new ArrayDeque&lt;&gt;();<a name="line.50"></a>
<span class="sourceLineNo">051</span><a name="line.51"></a>
<span class="sourceLineNo">052</span> private ScanMetrics scanMetrics;<a name="line.52"></a>
<span class="sourceLineNo">053</span><a name="line.53"></a>
<span class="sourceLineNo">054</span> private long cacheSize;<a name="line.54"></a>
<span class="sourceLineNo">055</span><a name="line.55"></a>
<span class="sourceLineNo">056</span> private boolean closed = false;<a name="line.56"></a>
<span class="sourceLineNo">057</span><a name="line.57"></a>
<span class="sourceLineNo">058</span> private Throwable error;<a name="line.58"></a>
<span class="sourceLineNo">059</span><a name="line.59"></a>
<span class="sourceLineNo">060</span> private ScanResumer resumer;<a name="line.60"></a>
<span class="sourceLineNo">061</span><a name="line.61"></a>
<span class="sourceLineNo">062</span> // Used to pass the span instance to the `AsyncTableImpl` from its underlying `rawAsyncTable`.<a name="line.62"></a>
<span class="sourceLineNo">063</span> private Span span = null;<a name="line.63"></a>
<span class="sourceLineNo">064</span><a name="line.64"></a>
<span class="sourceLineNo">065</span> public AsyncTableResultScanner(TableName tableName, Scan scan, long maxCacheSize) {<a name="line.65"></a>
<span class="sourceLineNo">066</span> this.tableName = tableName;<a name="line.66"></a>
<span class="sourceLineNo">067</span> this.maxCacheSize = maxCacheSize;<a name="line.67"></a>
<span class="sourceLineNo">068</span> this.scan = scan;<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> private void addToCache(Result result) {<a name="line.71"></a>
<span class="sourceLineNo">072</span> queue.add(result);<a name="line.72"></a>
<span class="sourceLineNo">073</span> cacheSize += calcEstimatedSize(result);<a name="line.73"></a>
<span class="sourceLineNo">074</span> }<a name="line.74"></a>
<span class="sourceLineNo">075</span><a name="line.75"></a>
<span class="sourceLineNo">076</span> private void stopPrefetch(ScanController controller) {<a name="line.76"></a>
<span class="sourceLineNo">077</span> if (LOG.isDebugEnabled()) {<a name="line.77"></a>
<span class="sourceLineNo">078</span> LOG.debug(<a name="line.78"></a>
<span class="sourceLineNo">079</span> "{} stop prefetching when scanning {} as the cache size {}"<a name="line.79"></a>
<span class="sourceLineNo">080</span> + " is greater than the maxCacheSize {}",<a name="line.80"></a>
<span class="sourceLineNo">081</span> String.format("0x%x", System.identityHashCode(this)), tableName, cacheSize, maxCacheSize);<a name="line.81"></a>
<span class="sourceLineNo">082</span> }<a name="line.82"></a>
<span class="sourceLineNo">083</span> resumer = controller.suspend();<a name="line.83"></a>
<span class="sourceLineNo">084</span> }<a name="line.84"></a>
<span class="sourceLineNo">085</span><a name="line.85"></a>
<span class="sourceLineNo">086</span> Span getSpan() {<a name="line.86"></a>
<span class="sourceLineNo">087</span> return span;<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> void setSpan(final Span span) {<a name="line.90"></a>
<span class="sourceLineNo">091</span> this.span = span;<a name="line.91"></a>
<span class="sourceLineNo">092</span> }<a name="line.92"></a>
<span class="sourceLineNo">093</span><a name="line.93"></a>
<span class="sourceLineNo">094</span> @Override<a name="line.94"></a>
<span class="sourceLineNo">095</span> public synchronized void onNext(Result[] results, ScanController controller) {<a name="line.95"></a>
<span class="sourceLineNo">096</span> assert results.length &gt; 0;<a name="line.96"></a>
<span class="sourceLineNo">097</span> if (closed) {<a name="line.97"></a>
<span class="sourceLineNo">098</span> controller.terminate();<a name="line.98"></a>
<span class="sourceLineNo">099</span> return;<a name="line.99"></a>
<span class="sourceLineNo">100</span> }<a name="line.100"></a>
<span class="sourceLineNo">101</span> for (Result result : results) {<a name="line.101"></a>
<span class="sourceLineNo">102</span> addToCache(result);<a name="line.102"></a>
<span class="sourceLineNo">103</span> }<a name="line.103"></a>
<span class="sourceLineNo">104</span> notifyAll();<a name="line.104"></a>
<span class="sourceLineNo">105</span> if (cacheSize &gt;= maxCacheSize) {<a name="line.105"></a>
<span class="sourceLineNo">106</span> stopPrefetch(controller);<a name="line.106"></a>
<span class="sourceLineNo">107</span> }<a name="line.107"></a>
<span class="sourceLineNo">108</span> }<a name="line.108"></a>
<span class="sourceLineNo">109</span><a name="line.109"></a>
<span class="sourceLineNo">110</span> @Override<a name="line.110"></a>
<span class="sourceLineNo">111</span> public synchronized void onHeartbeat(ScanController controller) {<a name="line.111"></a>
<span class="sourceLineNo">112</span> if (closed) {<a name="line.112"></a>
<span class="sourceLineNo">113</span> controller.terminate();<a name="line.113"></a>
<span class="sourceLineNo">114</span> return;<a name="line.114"></a>
<span class="sourceLineNo">115</span> }<a name="line.115"></a>
<span class="sourceLineNo">116</span> if (scan.isNeedCursorResult()) {<a name="line.116"></a>
<span class="sourceLineNo">117</span> controller.cursor().ifPresent(c -&gt; queue.add(Result.createCursorResult(c)));<a name="line.117"></a>
<span class="sourceLineNo">118</span> }<a name="line.118"></a>
<span class="sourceLineNo">119</span> }<a name="line.119"></a>
<span class="sourceLineNo">120</span><a name="line.120"></a>
<span class="sourceLineNo">121</span> @Override<a name="line.121"></a>
<span class="sourceLineNo">122</span> public synchronized void onError(Throwable error) {<a name="line.122"></a>
<span class="sourceLineNo">123</span> this.error = error;<a name="line.123"></a>
<span class="sourceLineNo">124</span> notifyAll();<a name="line.124"></a>
<span class="sourceLineNo">125</span> }<a name="line.125"></a>
<span class="sourceLineNo">126</span><a name="line.126"></a>
<span class="sourceLineNo">127</span> @Override<a name="line.127"></a>
<span class="sourceLineNo">128</span> public synchronized void onComplete() {<a name="line.128"></a>
<span class="sourceLineNo">129</span> closed = true;<a name="line.129"></a>
<span class="sourceLineNo">130</span> notifyAll();<a name="line.130"></a>
<span class="sourceLineNo">131</span> }<a name="line.131"></a>
<span class="sourceLineNo">132</span><a name="line.132"></a>
<span class="sourceLineNo">133</span> @Override<a name="line.133"></a>
<span class="sourceLineNo">134</span> public void onScanMetricsCreated(ScanMetrics scanMetrics) {<a name="line.134"></a>
<span class="sourceLineNo">135</span> this.scanMetrics = scanMetrics;<a name="line.135"></a>
<span class="sourceLineNo">136</span> }<a name="line.136"></a>
<span class="sourceLineNo">137</span><a name="line.137"></a>
<span class="sourceLineNo">138</span> private void resumePrefetch() {<a name="line.138"></a>
<span class="sourceLineNo">139</span> if (LOG.isDebugEnabled()) {<a name="line.139"></a>
<span class="sourceLineNo">140</span> LOG.debug(String.format("0x%x", System.identityHashCode(this)) + " resume prefetching");<a name="line.140"></a>
<span class="sourceLineNo">141</span> }<a name="line.141"></a>
<span class="sourceLineNo">142</span> resumer.resume();<a name="line.142"></a>
<span class="sourceLineNo">143</span> resumer = null;<a name="line.143"></a>
<span class="sourceLineNo">144</span> }<a name="line.144"></a>
<span class="sourceLineNo">145</span><a name="line.145"></a>
<span class="sourceLineNo">146</span> @Override<a name="line.146"></a>
<span class="sourceLineNo">147</span> public synchronized Result next() throws IOException {<a name="line.147"></a>
<span class="sourceLineNo">148</span> while (queue.isEmpty()) {<a name="line.148"></a>
<span class="sourceLineNo">149</span> if (closed) {<a name="line.149"></a>
<span class="sourceLineNo">150</span> return null;<a name="line.150"></a>
<span class="sourceLineNo">151</span> }<a name="line.151"></a>
<span class="sourceLineNo">152</span> if (error != null) {<a name="line.152"></a>
<span class="sourceLineNo">153</span> throw FutureUtils.rethrow(error);<a name="line.153"></a>
<span class="sourceLineNo">154</span> }<a name="line.154"></a>
<span class="sourceLineNo">155</span> try {<a name="line.155"></a>
<span class="sourceLineNo">156</span> wait();<a name="line.156"></a>
<span class="sourceLineNo">157</span> } catch (InterruptedException e) {<a name="line.157"></a>
<span class="sourceLineNo">158</span> throw new InterruptedIOException();<a name="line.158"></a>
<span class="sourceLineNo">159</span> }<a name="line.159"></a>
<span class="sourceLineNo">160</span> }<a name="line.160"></a>
<span class="sourceLineNo">161</span> Result result = queue.poll();<a name="line.161"></a>
<span class="sourceLineNo">162</span> if (!result.isCursor()) {<a name="line.162"></a>
<span class="sourceLineNo">163</span> cacheSize -= calcEstimatedSize(result);<a name="line.163"></a>
<span class="sourceLineNo">164</span> if (resumer != null &amp;&amp; cacheSize &lt;= maxCacheSize / 2) {<a name="line.164"></a>
<span class="sourceLineNo">165</span> resumePrefetch();<a name="line.165"></a>
<span class="sourceLineNo">166</span> }<a name="line.166"></a>
<span class="sourceLineNo">167</span> }<a name="line.167"></a>
<span class="sourceLineNo">168</span> return result;<a name="line.168"></a>
<span class="sourceLineNo">169</span> }<a name="line.169"></a>
<span class="sourceLineNo">170</span><a name="line.170"></a>
<span class="sourceLineNo">171</span> @Override<a name="line.171"></a>
<span class="sourceLineNo">172</span> public synchronized void close() {<a name="line.172"></a>
<span class="sourceLineNo">173</span> closed = true;<a name="line.173"></a>
<span class="sourceLineNo">174</span> queue.clear();<a name="line.174"></a>
<span class="sourceLineNo">175</span> cacheSize = 0;<a name="line.175"></a>
<span class="sourceLineNo">176</span> if (resumer != null) {<a name="line.176"></a>
<span class="sourceLineNo">177</span> resumePrefetch();<a name="line.177"></a>
<span class="sourceLineNo">178</span> }<a name="line.178"></a>
<span class="sourceLineNo">179</span> notifyAll();<a name="line.179"></a>
<span class="sourceLineNo">180</span> }<a name="line.180"></a>
<span class="sourceLineNo">181</span><a name="line.181"></a>
<span class="sourceLineNo">182</span> @Override<a name="line.182"></a>
<span class="sourceLineNo">183</span> public boolean renewLease() {<a name="line.183"></a>
<span class="sourceLineNo">184</span> // we will do prefetching in the background and if there is no space we will just suspend the<a name="line.184"></a>
<span class="sourceLineNo">185</span> // scanner. The renew lease operation will be handled in the background.<a name="line.185"></a>
<span class="sourceLineNo">186</span> return false;<a name="line.186"></a>
<span class="sourceLineNo">187</span> }<a name="line.187"></a>
<span class="sourceLineNo">188</span><a name="line.188"></a>
<span class="sourceLineNo">189</span> // used in tests to test whether the scanner has been suspended<a name="line.189"></a>
<span class="sourceLineNo">190</span> synchronized boolean isSuspended() {<a name="line.190"></a>
<span class="sourceLineNo">191</span> return resumer != null;<a name="line.191"></a>
<span class="sourceLineNo">192</span> }<a name="line.192"></a>
<span class="sourceLineNo">193</span><a name="line.193"></a>
<span class="sourceLineNo">194</span> @Override<a name="line.194"></a>
<span class="sourceLineNo">195</span> public ScanMetrics getScanMetrics() {<a name="line.195"></a>
<span class="sourceLineNo">196</span> return scanMetrics;<a name="line.196"></a>
<span class="sourceLineNo">197</span> }<a name="line.197"></a>
<span class="sourceLineNo">198</span><a name="line.198"></a>
<span class="sourceLineNo">199</span> int getCacheSize() {<a name="line.199"></a>
<span class="sourceLineNo">200</span> return queue.size();<a name="line.200"></a>
<span class="sourceLineNo">201</span> }<a name="line.201"></a>
<span class="sourceLineNo">202</span>}<a name="line.202"></a>
</pre>
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