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| <pre><span class="source-line-no">001</span><span id="line-1">/*</span> |
| <span class="source-line-no">002</span><span id="line-2"> * Licensed to the Apache Software Foundation (ASF) under one</span> |
| <span class="source-line-no">003</span><span id="line-3"> * or more contributor license agreements. See the NOTICE file</span> |
| <span class="source-line-no">004</span><span id="line-4"> * distributed with this work for additional information</span> |
| <span class="source-line-no">005</span><span id="line-5"> * regarding copyright ownership. The ASF licenses this file</span> |
| <span class="source-line-no">006</span><span id="line-6"> * to you under the Apache License, Version 2.0 (the</span> |
| <span class="source-line-no">007</span><span id="line-7"> * "License"); you may not use this file except in compliance</span> |
| <span class="source-line-no">008</span><span id="line-8"> * with the License. You may obtain a copy of the License at</span> |
| <span class="source-line-no">009</span><span id="line-9"> *</span> |
| <span class="source-line-no">010</span><span id="line-10"> * http://www.apache.org/licenses/LICENSE-2.0</span> |
| <span class="source-line-no">011</span><span id="line-11"> *</span> |
| <span class="source-line-no">012</span><span id="line-12"> * Unless required by applicable law or agreed to in writing, software</span> |
| <span class="source-line-no">013</span><span id="line-13"> * distributed under the License is distributed on an "AS IS" BASIS,</span> |
| <span class="source-line-no">014</span><span id="line-14"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span> |
| <span class="source-line-no">015</span><span id="line-15"> * See the License for the specific language governing permissions and</span> |
| <span class="source-line-no">016</span><span id="line-16"> * limitations under the License.</span> |
| <span class="source-line-no">017</span><span id="line-17"> */</span> |
| <span class="source-line-no">018</span><span id="line-18">package org.apache.hadoop.hbase.regionserver;</span> |
| <span class="source-line-no">019</span><span id="line-19"></span> |
| <span class="source-line-no">020</span><span id="line-20">import java.io.IOException;</span> |
| <span class="source-line-no">021</span><span id="line-21">import java.util.ArrayList;</span> |
| <span class="source-line-no">022</span><span id="line-22">import java.util.Comparator;</span> |
| <span class="source-line-no">023</span><span id="line-23">import java.util.List;</span> |
| <span class="source-line-no">024</span><span id="line-24">import java.util.PriorityQueue;</span> |
| <span class="source-line-no">025</span><span id="line-25">import java.util.function.IntConsumer;</span> |
| <span class="source-line-no">026</span><span id="line-26">import org.apache.hadoop.hbase.Cell;</span> |
| <span class="source-line-no">027</span><span id="line-27">import org.apache.hadoop.hbase.CellComparator;</span> |
| <span class="source-line-no">028</span><span id="line-28">import org.apache.hadoop.hbase.ExtendedCell;</span> |
| <span class="source-line-no">029</span><span id="line-29">import org.apache.hadoop.hbase.regionserver.ScannerContext.NextState;</span> |
| <span class="source-line-no">030</span><span id="line-30">import org.apache.yetus.audience.InterfaceAudience;</span> |
| <span class="source-line-no">031</span><span id="line-31">import org.slf4j.Logger;</span> |
| <span class="source-line-no">032</span><span id="line-32">import org.slf4j.LoggerFactory;</span> |
| <span class="source-line-no">033</span><span id="line-33"></span> |
| <span class="source-line-no">034</span><span id="line-34">/**</span> |
| <span class="source-line-no">035</span><span id="line-35"> * Implements a heap merge across any number of KeyValueScanners.</span> |
| <span class="source-line-no">036</span><span id="line-36"> * <p></span> |
| <span class="source-line-no">037</span><span id="line-37"> * Implements KeyValueScanner itself.</span> |
| <span class="source-line-no">038</span><span id="line-38"> * <p></span> |
| <span class="source-line-no">039</span><span id="line-39"> * This class is used at the Region level to merge across Stores and at the Store level to merge</span> |
| <span class="source-line-no">040</span><span id="line-40"> * across the memstore and StoreFiles.</span> |
| <span class="source-line-no">041</span><span id="line-41"> * <p></span> |
| <span class="source-line-no">042</span><span id="line-42"> * In the Region case, we also need InternalScanner.next(List), so this class also implements</span> |
| <span class="source-line-no">043</span><span id="line-43"> * InternalScanner. WARNING: As is, if you try to use this as an InternalScanner at the Store level,</span> |
| <span class="source-line-no">044</span><span id="line-44"> * you will get runtime exceptions.</span> |
| <span class="source-line-no">045</span><span id="line-45"> */</span> |
| <span class="source-line-no">046</span><span id="line-46">@InterfaceAudience.Private</span> |
| <span class="source-line-no">047</span><span id="line-47">public class KeyValueHeap extends NonReversedNonLazyKeyValueScanner</span> |
| <span class="source-line-no">048</span><span id="line-48"> implements KeyValueScanner, InternalScanner {</span> |
| <span class="source-line-no">049</span><span id="line-49"> private static final Logger LOG = LoggerFactory.getLogger(KeyValueHeap.class);</span> |
| <span class="source-line-no">050</span><span id="line-50"> protected PriorityQueue<KeyValueScanner> heap = null;</span> |
| <span class="source-line-no">051</span><span id="line-51"> // Holds the scanners when a ever a eager close() happens. All such eagerly closed</span> |
| <span class="source-line-no">052</span><span id="line-52"> // scans are collected and when the final scanner.close() happens will perform the</span> |
| <span class="source-line-no">053</span><span id="line-53"> // actual close.</span> |
| <span class="source-line-no">054</span><span id="line-54"> protected List<KeyValueScanner> scannersForDelayedClose = null;</span> |
| <span class="source-line-no">055</span><span id="line-55"></span> |
| <span class="source-line-no">056</span><span id="line-56"> /**</span> |
| <span class="source-line-no">057</span><span id="line-57"> * The current sub-scanner, i.e. the one that contains the next key/value to return to the client.</span> |
| <span class="source-line-no">058</span><span id="line-58"> * This scanner is NOT included in {@link #heap} (but we frequently add it back to the heap and</span> |
| <span class="source-line-no">059</span><span id="line-59"> * pull the new winner out). We maintain an invariant that the current sub-scanner has already</span> |
| <span class="source-line-no">060</span><span id="line-60"> * done a real seek, and that current.peek() is always a real key/value (or null) except for the</span> |
| <span class="source-line-no">061</span><span id="line-61"> * fake last-key-on-row-column supplied by the multi-column Bloom filter optimization, which is OK</span> |
| <span class="source-line-no">062</span><span id="line-62"> * to propagate to StoreScanner. In order to ensure that, always use {@link #pollRealKV()} to</span> |
| <span class="source-line-no">063</span><span id="line-63"> * update current.</span> |
| <span class="source-line-no">064</span><span id="line-64"> */</span> |
| <span class="source-line-no">065</span><span id="line-65"> protected KeyValueScanner current = null;</span> |
| <span class="source-line-no">066</span><span id="line-66"></span> |
| <span class="source-line-no">067</span><span id="line-67"> protected KVScannerComparator comparator;</span> |
| <span class="source-line-no">068</span><span id="line-68"></span> |
| <span class="source-line-no">069</span><span id="line-69"> /**</span> |
| <span class="source-line-no">070</span><span id="line-70"> * Constructor. This KeyValueHeap will handle closing of passed in KeyValueScanners.</span> |
| <span class="source-line-no">071</span><span id="line-71"> */</span> |
| <span class="source-line-no">072</span><span id="line-72"> public KeyValueHeap(List<? extends KeyValueScanner> scanners, CellComparator comparator)</span> |
| <span class="source-line-no">073</span><span id="line-73"> throws IOException {</span> |
| <span class="source-line-no">074</span><span id="line-74"> this(scanners, new KVScannerComparator(comparator));</span> |
| <span class="source-line-no">075</span><span id="line-75"> }</span> |
| <span class="source-line-no">076</span><span id="line-76"></span> |
| <span class="source-line-no">077</span><span id="line-77"> /**</span> |
| <span class="source-line-no">078</span><span id="line-78"> * Constructor.</span> |
| <span class="source-line-no">079</span><span id="line-79"> */</span> |
| <span class="source-line-no">080</span><span id="line-80"> KeyValueHeap(List<? extends KeyValueScanner> scanners, KVScannerComparator comparator)</span> |
| <span class="source-line-no">081</span><span id="line-81"> throws IOException {</span> |
| <span class="source-line-no">082</span><span id="line-82"> this.comparator = comparator;</span> |
| <span class="source-line-no">083</span><span id="line-83"> this.scannersForDelayedClose = new ArrayList<>(scanners.size());</span> |
| <span class="source-line-no">084</span><span id="line-84"> if (!scanners.isEmpty()) {</span> |
| <span class="source-line-no">085</span><span id="line-85"> this.heap = new PriorityQueue<>(scanners.size(), this.comparator);</span> |
| <span class="source-line-no">086</span><span id="line-86"> for (KeyValueScanner scanner : scanners) {</span> |
| <span class="source-line-no">087</span><span id="line-87"> if (scanner.peek() != null) {</span> |
| <span class="source-line-no">088</span><span id="line-88"> this.heap.add(scanner);</span> |
| <span class="source-line-no">089</span><span id="line-89"> } else {</span> |
| <span class="source-line-no">090</span><span id="line-90"> this.scannersForDelayedClose.add(scanner);</span> |
| <span class="source-line-no">091</span><span id="line-91"> }</span> |
| <span class="source-line-no">092</span><span id="line-92"> }</span> |
| <span class="source-line-no">093</span><span id="line-93"> this.current = pollRealKV();</span> |
| <span class="source-line-no">094</span><span id="line-94"> }</span> |
| <span class="source-line-no">095</span><span id="line-95"> }</span> |
| <span class="source-line-no">096</span><span id="line-96"></span> |
| <span class="source-line-no">097</span><span id="line-97"> @Override</span> |
| <span class="source-line-no">098</span><span id="line-98"> public ExtendedCell peek() {</span> |
| <span class="source-line-no">099</span><span id="line-99"> if (this.current == null) {</span> |
| <span class="source-line-no">100</span><span id="line-100"> return null;</span> |
| <span class="source-line-no">101</span><span id="line-101"> }</span> |
| <span class="source-line-no">102</span><span id="line-102"> return this.current.peek();</span> |
| <span class="source-line-no">103</span><span id="line-103"> }</span> |
| <span class="source-line-no">104</span><span id="line-104"></span> |
| <span class="source-line-no">105</span><span id="line-105"> boolean isLatestCellFromMemstore() {</span> |
| <span class="source-line-no">106</span><span id="line-106"> return !this.current.isFileScanner();</span> |
| <span class="source-line-no">107</span><span id="line-107"> }</span> |
| <span class="source-line-no">108</span><span id="line-108"></span> |
| <span class="source-line-no">109</span><span id="line-109"> @Override</span> |
| <span class="source-line-no">110</span><span id="line-110"> public void recordBlockSize(IntConsumer blockSizeConsumer) {</span> |
| <span class="source-line-no">111</span><span id="line-111"> this.current.recordBlockSize(blockSizeConsumer);</span> |
| <span class="source-line-no">112</span><span id="line-112"> }</span> |
| <span class="source-line-no">113</span><span id="line-113"></span> |
| <span class="source-line-no">114</span><span id="line-114"> @Override</span> |
| <span class="source-line-no">115</span><span id="line-115"> public ExtendedCell next() throws IOException {</span> |
| <span class="source-line-no">116</span><span id="line-116"> if (this.current == null) {</span> |
| <span class="source-line-no">117</span><span id="line-117"> return null;</span> |
| <span class="source-line-no">118</span><span id="line-118"> }</span> |
| <span class="source-line-no">119</span><span id="line-119"> ExtendedCell kvReturn = this.current.next();</span> |
| <span class="source-line-no">120</span><span id="line-120"> ExtendedCell kvNext = this.current.peek();</span> |
| <span class="source-line-no">121</span><span id="line-121"> if (kvNext == null) {</span> |
| <span class="source-line-no">122</span><span id="line-122"> this.scannersForDelayedClose.add(this.current);</span> |
| <span class="source-line-no">123</span><span id="line-123"> this.current = null;</span> |
| <span class="source-line-no">124</span><span id="line-124"> this.current = pollRealKV();</span> |
| <span class="source-line-no">125</span><span id="line-125"> } else {</span> |
| <span class="source-line-no">126</span><span id="line-126"> KeyValueScanner topScanner = this.heap.peek();</span> |
| <span class="source-line-no">127</span><span id="line-127"> // no need to add current back to the heap if it is the only scanner left</span> |
| <span class="source-line-no">128</span><span id="line-128"> if (topScanner != null && this.comparator.compare(kvNext, topScanner.peek()) >= 0) {</span> |
| <span class="source-line-no">129</span><span id="line-129"> this.heap.add(this.current);</span> |
| <span class="source-line-no">130</span><span id="line-130"> this.current = null;</span> |
| <span class="source-line-no">131</span><span id="line-131"> this.current = pollRealKV();</span> |
| <span class="source-line-no">132</span><span id="line-132"> }</span> |
| <span class="source-line-no">133</span><span id="line-133"> }</span> |
| <span class="source-line-no">134</span><span id="line-134"> return kvReturn;</span> |
| <span class="source-line-no">135</span><span id="line-135"> }</span> |
| <span class="source-line-no">136</span><span id="line-136"></span> |
| <span class="source-line-no">137</span><span id="line-137"> /**</span> |
| <span class="source-line-no">138</span><span id="line-138"> * Gets the next row of keys from the top-most scanner.</span> |
| <span class="source-line-no">139</span><span id="line-139"> * <p></span> |
| <span class="source-line-no">140</span><span id="line-140"> * This method takes care of updating the heap.</span> |
| <span class="source-line-no">141</span><span id="line-141"> * <p></span> |
| <span class="source-line-no">142</span><span id="line-142"> * This can ONLY be called when you are using Scanners that implement InternalScanner as well as</span> |
| <span class="source-line-no">143</span><span id="line-143"> * KeyValueScanner (a {@link StoreScanner}).</span> |
| <span class="source-line-no">144</span><span id="line-144"> * @return true if more rows exist after this one, false if scanner is done</span> |
| <span class="source-line-no">145</span><span id="line-145"> */</span> |
| <span class="source-line-no">146</span><span id="line-146"> @Override</span> |
| <span class="source-line-no">147</span><span id="line-147"> public boolean next(List<? super ExtendedCell> result, ScannerContext scannerContext)</span> |
| <span class="source-line-no">148</span><span id="line-148"> throws IOException {</span> |
| <span class="source-line-no">149</span><span id="line-149"> if (this.current == null) {</span> |
| <span class="source-line-no">150</span><span id="line-150"> return scannerContext.setScannerState(NextState.NO_MORE_VALUES).hasMoreValues();</span> |
| <span class="source-line-no">151</span><span id="line-151"> }</span> |
| <span class="source-line-no">152</span><span id="line-152"> InternalScanner currentAsInternal = (InternalScanner) this.current;</span> |
| <span class="source-line-no">153</span><span id="line-153"> boolean moreCells = currentAsInternal.next(result, scannerContext);</span> |
| <span class="source-line-no">154</span><span id="line-154"> Cell pee = this.current.peek();</span> |
| <span class="source-line-no">155</span><span id="line-155"></span> |
| <span class="source-line-no">156</span><span id="line-156"> /*</span> |
| <span class="source-line-no">157</span><span id="line-157"> * By definition, any InternalScanner must return false only when it has no further rows to be</span> |
| <span class="source-line-no">158</span><span id="line-158"> * fetched. So, we can close a scanner if it returns false. All existing implementations seem to</span> |
| <span class="source-line-no">159</span><span id="line-159"> * be fine with this. It is much more efficient to close scanners which are not needed than keep</span> |
| <span class="source-line-no">160</span><span id="line-160"> * them in the heap. This is also required for certain optimizations.</span> |
| <span class="source-line-no">161</span><span id="line-161"> */</span> |
| <span class="source-line-no">162</span><span id="line-162"></span> |
| <span class="source-line-no">163</span><span id="line-163"> if (pee == null || !moreCells) {</span> |
| <span class="source-line-no">164</span><span id="line-164"> // add the scanner that is to be closed</span> |
| <span class="source-line-no">165</span><span id="line-165"> this.scannersForDelayedClose.add(this.current);</span> |
| <span class="source-line-no">166</span><span id="line-166"> } else {</span> |
| <span class="source-line-no">167</span><span id="line-167"> this.heap.add(this.current);</span> |
| <span class="source-line-no">168</span><span id="line-168"> }</span> |
| <span class="source-line-no">169</span><span id="line-169"> this.current = null;</span> |
| <span class="source-line-no">170</span><span id="line-170"> this.current = pollRealKV();</span> |
| <span class="source-line-no">171</span><span id="line-171"> if (this.current == null) {</span> |
| <span class="source-line-no">172</span><span id="line-172"> moreCells = scannerContext.setScannerState(NextState.NO_MORE_VALUES).hasMoreValues();</span> |
| <span class="source-line-no">173</span><span id="line-173"> }</span> |
| <span class="source-line-no">174</span><span id="line-174"> return moreCells;</span> |
| <span class="source-line-no">175</span><span id="line-175"> }</span> |
| <span class="source-line-no">176</span><span id="line-176"></span> |
| <span class="source-line-no">177</span><span id="line-177"> protected static class KVScannerComparator implements Comparator<KeyValueScanner> {</span> |
| <span class="source-line-no">178</span><span id="line-178"> protected CellComparator kvComparator;</span> |
| <span class="source-line-no">179</span><span id="line-179"></span> |
| <span class="source-line-no">180</span><span id="line-180"> /**</span> |
| <span class="source-line-no">181</span><span id="line-181"> * Constructor</span> |
| <span class="source-line-no">182</span><span id="line-182"> */</span> |
| <span class="source-line-no">183</span><span id="line-183"> public KVScannerComparator(CellComparator kvComparator) {</span> |
| <span class="source-line-no">184</span><span id="line-184"> this.kvComparator = kvComparator;</span> |
| <span class="source-line-no">185</span><span id="line-185"> }</span> |
| <span class="source-line-no">186</span><span id="line-186"></span> |
| <span class="source-line-no">187</span><span id="line-187"> @Override</span> |
| <span class="source-line-no">188</span><span id="line-188"> public int compare(KeyValueScanner left, KeyValueScanner right) {</span> |
| <span class="source-line-no">189</span><span id="line-189"> int comparison = compare(left.peek(), right.peek());</span> |
| <span class="source-line-no">190</span><span id="line-190"> if (comparison != 0) {</span> |
| <span class="source-line-no">191</span><span id="line-191"> return comparison;</span> |
| <span class="source-line-no">192</span><span id="line-192"> } else {</span> |
| <span class="source-line-no">193</span><span id="line-193"> // Since both the keys are exactly the same, we break the tie in favor of higher ordered</span> |
| <span class="source-line-no">194</span><span id="line-194"> // scanner since it'll have newer data. Since higher value should come first, we reverse</span> |
| <span class="source-line-no">195</span><span id="line-195"> // sort here.</span> |
| <span class="source-line-no">196</span><span id="line-196"> return Long.compare(right.getScannerOrder(), left.getScannerOrder());</span> |
| <span class="source-line-no">197</span><span id="line-197"> }</span> |
| <span class="source-line-no">198</span><span id="line-198"> }</span> |
| <span class="source-line-no">199</span><span id="line-199"></span> |
| <span class="source-line-no">200</span><span id="line-200"> /**</span> |
| <span class="source-line-no">201</span><span id="line-201"> * Compares two KeyValue</span> |
| <span class="source-line-no">202</span><span id="line-202"> * @return less than 0 if left is smaller, 0 if equal etc..</span> |
| <span class="source-line-no">203</span><span id="line-203"> */</span> |
| <span class="source-line-no">204</span><span id="line-204"> public int compare(Cell left, Cell right) {</span> |
| <span class="source-line-no">205</span><span id="line-205"> return this.kvComparator.compare(left, right);</span> |
| <span class="source-line-no">206</span><span id="line-206"> }</span> |
| <span class="source-line-no">207</span><span id="line-207"></span> |
| <span class="source-line-no">208</span><span id="line-208"> /**</span> |
| <span class="source-line-no">209</span><span id="line-209"> * */</span> |
| <span class="source-line-no">210</span><span id="line-210"> public CellComparator getComparator() {</span> |
| <span class="source-line-no">211</span><span id="line-211"> return this.kvComparator;</span> |
| <span class="source-line-no">212</span><span id="line-212"> }</span> |
| <span class="source-line-no">213</span><span id="line-213"> }</span> |
| <span class="source-line-no">214</span><span id="line-214"></span> |
| <span class="source-line-no">215</span><span id="line-215"> @Override</span> |
| <span class="source-line-no">216</span><span id="line-216"> public void close() {</span> |
| <span class="source-line-no">217</span><span id="line-217"> for (KeyValueScanner scanner : this.scannersForDelayedClose) {</span> |
| <span class="source-line-no">218</span><span id="line-218"> scanner.close();</span> |
| <span class="source-line-no">219</span><span id="line-219"> }</span> |
| <span class="source-line-no">220</span><span id="line-220"> this.scannersForDelayedClose.clear();</span> |
| <span class="source-line-no">221</span><span id="line-221"> if (this.current != null) {</span> |
| <span class="source-line-no">222</span><span id="line-222"> this.current.close();</span> |
| <span class="source-line-no">223</span><span id="line-223"> }</span> |
| <span class="source-line-no">224</span><span id="line-224"> if (this.heap != null) {</span> |
| <span class="source-line-no">225</span><span id="line-225"> // Order of closing the scanners shouldn't matter here, so simply iterate and close them.</span> |
| <span class="source-line-no">226</span><span id="line-226"> for (KeyValueScanner scanner : heap) {</span> |
| <span class="source-line-no">227</span><span id="line-227"> scanner.close();</span> |
| <span class="source-line-no">228</span><span id="line-228"> }</span> |
| <span class="source-line-no">229</span><span id="line-229"> }</span> |
| <span class="source-line-no">230</span><span id="line-230"> }</span> |
| <span class="source-line-no">231</span><span id="line-231"></span> |
| <span class="source-line-no">232</span><span id="line-232"> /**</span> |
| <span class="source-line-no">233</span><span id="line-233"> * Seeks all scanners at or below the specified seek key. If we earlied-out of a row, we may end</span> |
| <span class="source-line-no">234</span><span id="line-234"> * up skipping values that were never reached yet. Rather than iterating down, we want to give the</span> |
| <span class="source-line-no">235</span><span id="line-235"> * opportunity to re-seek.</span> |
| <span class="source-line-no">236</span><span id="line-236"> * <p></span> |
| <span class="source-line-no">237</span><span id="line-237"> * As individual scanners may run past their ends, those scanners are automatically closed and</span> |
| <span class="source-line-no">238</span><span id="line-238"> * removed from the heap.</span> |
| <span class="source-line-no">239</span><span id="line-239"> * <p></span> |
| <span class="source-line-no">240</span><span id="line-240"> * This function (and {@link #reseek(ExtendedCell)}) does not do multi-column Bloom filter and</span> |
| <span class="source-line-no">241</span><span id="line-241"> * lazy-seek optimizations. To enable those, call</span> |
| <span class="source-line-no">242</span><span id="line-242"> * {@link #requestSeek(ExtendedCell, boolean, boolean)}.</span> |
| <span class="source-line-no">243</span><span id="line-243"> * @param seekKey KeyValue to seek at or after</span> |
| <span class="source-line-no">244</span><span id="line-244"> * @return true if KeyValues exist at or after specified key, false if not</span> |
| <span class="source-line-no">245</span><span id="line-245"> */</span> |
| <span class="source-line-no">246</span><span id="line-246"> @Override</span> |
| <span class="source-line-no">247</span><span id="line-247"> public boolean seek(ExtendedCell seekKey) throws IOException {</span> |
| <span class="source-line-no">248</span><span id="line-248"> return generalizedSeek(false, // This is not a lazy seek</span> |
| <span class="source-line-no">249</span><span id="line-249"> seekKey, false, // forward (false: this is not a reseek)</span> |
| <span class="source-line-no">250</span><span id="line-250"> false); // Not using Bloom filters</span> |
| <span class="source-line-no">251</span><span id="line-251"> }</span> |
| <span class="source-line-no">252</span><span id="line-252"></span> |
| <span class="source-line-no">253</span><span id="line-253"> /**</span> |
| <span class="source-line-no">254</span><span id="line-254"> * This function is identical to the {@link #seek(ExtendedCell)} function except that</span> |
| <span class="source-line-no">255</span><span id="line-255"> * scanner.seek(seekKey) is changed to scanner.reseek(seekKey).</span> |
| <span class="source-line-no">256</span><span id="line-256"> */</span> |
| <span class="source-line-no">257</span><span id="line-257"> @Override</span> |
| <span class="source-line-no">258</span><span id="line-258"> public boolean reseek(ExtendedCell seekKey) throws IOException {</span> |
| <span class="source-line-no">259</span><span id="line-259"> return generalizedSeek(false, // This is not a lazy seek</span> |
| <span class="source-line-no">260</span><span id="line-260"> seekKey, true, // forward (true because this is reseek)</span> |
| <span class="source-line-no">261</span><span id="line-261"> false); // Not using Bloom filters</span> |
| <span class="source-line-no">262</span><span id="line-262"> }</span> |
| <span class="source-line-no">263</span><span id="line-263"></span> |
| <span class="source-line-no">264</span><span id="line-264"> /**</span> |
| <span class="source-line-no">265</span><span id="line-265"> * {@inheritDoc}</span> |
| <span class="source-line-no">266</span><span id="line-266"> */</span> |
| <span class="source-line-no">267</span><span id="line-267"> @Override</span> |
| <span class="source-line-no">268</span><span id="line-268"> public boolean requestSeek(ExtendedCell key, boolean forward, boolean useBloom)</span> |
| <span class="source-line-no">269</span><span id="line-269"> throws IOException {</span> |
| <span class="source-line-no">270</span><span id="line-270"> return generalizedSeek(true, key, forward, useBloom);</span> |
| <span class="source-line-no">271</span><span id="line-271"> }</span> |
| <span class="source-line-no">272</span><span id="line-272"></span> |
| <span class="source-line-no">273</span><span id="line-273"> /**</span> |
| <span class="source-line-no">274</span><span id="line-274"> * @param isLazy whether we are trying to seek to exactly the given row/col. Enables Bloom</span> |
| <span class="source-line-no">275</span><span id="line-275"> * filter and most-recent-file-first optimizations for multi-column get/scan</span> |
| <span class="source-line-no">276</span><span id="line-276"> * queries.</span> |
| <span class="source-line-no">277</span><span id="line-277"> * @param seekKey key to seek to</span> |
| <span class="source-line-no">278</span><span id="line-278"> * @param forward whether to seek forward (also known as reseek)</span> |
| <span class="source-line-no">279</span><span id="line-279"> * @param useBloom whether to optimize seeks using Bloom filters</span> |
| <span class="source-line-no">280</span><span id="line-280"> */</span> |
| <span class="source-line-no">281</span><span id="line-281"> private boolean generalizedSeek(boolean isLazy, ExtendedCell seekKey, boolean forward,</span> |
| <span class="source-line-no">282</span><span id="line-282"> boolean useBloom) throws IOException {</span> |
| <span class="source-line-no">283</span><span id="line-283"> if (!isLazy && useBloom) {</span> |
| <span class="source-line-no">284</span><span id="line-284"> throw new IllegalArgumentException(</span> |
| <span class="source-line-no">285</span><span id="line-285"> "Multi-column Bloom filter " + "optimization requires a lazy seek");</span> |
| <span class="source-line-no">286</span><span id="line-286"> }</span> |
| <span class="source-line-no">287</span><span id="line-287"></span> |
| <span class="source-line-no">288</span><span id="line-288"> if (current == null) {</span> |
| <span class="source-line-no">289</span><span id="line-289"> return false;</span> |
| <span class="source-line-no">290</span><span id="line-290"> }</span> |
| <span class="source-line-no">291</span><span id="line-291"></span> |
| <span class="source-line-no">292</span><span id="line-292"> KeyValueScanner scanner = current;</span> |
| <span class="source-line-no">293</span><span id="line-293"> try {</span> |
| <span class="source-line-no">294</span><span id="line-294"> while (scanner != null) {</span> |
| <span class="source-line-no">295</span><span id="line-295"> Cell topKey = scanner.peek();</span> |
| <span class="source-line-no">296</span><span id="line-296"> if (comparator.getComparator().compare(seekKey, topKey) <= 0) {</span> |
| <span class="source-line-no">297</span><span id="line-297"> // Top KeyValue is at-or-after Seek KeyValue. We only know that all</span> |
| <span class="source-line-no">298</span><span id="line-298"> // scanners are at or after seekKey (because fake keys of</span> |
| <span class="source-line-no">299</span><span id="line-299"> // scanners where a lazy-seek operation has been done are not greater</span> |
| <span class="source-line-no">300</span><span id="line-300"> // than their real next keys) but we still need to enforce our</span> |
| <span class="source-line-no">301</span><span id="line-301"> // invariant that the top scanner has done a real seek. This way</span> |
| <span class="source-line-no">302</span><span id="line-302"> // StoreScanner and RegionScanner do not have to worry about fake</span> |
| <span class="source-line-no">303</span><span id="line-303"> // keys.</span> |
| <span class="source-line-no">304</span><span id="line-304"> heap.add(scanner);</span> |
| <span class="source-line-no">305</span><span id="line-305"> scanner = null;</span> |
| <span class="source-line-no">306</span><span id="line-306"> current = pollRealKV();</span> |
| <span class="source-line-no">307</span><span id="line-307"> return current != null;</span> |
| <span class="source-line-no">308</span><span id="line-308"> }</span> |
| <span class="source-line-no">309</span><span id="line-309"></span> |
| <span class="source-line-no">310</span><span id="line-310"> boolean seekResult;</span> |
| <span class="source-line-no">311</span><span id="line-311"> if (isLazy && heap.size() > 0) {</span> |
| <span class="source-line-no">312</span><span id="line-312"> // If there is only one scanner left, we don't do lazy seek.</span> |
| <span class="source-line-no">313</span><span id="line-313"> seekResult = scanner.requestSeek(seekKey, forward, useBloom);</span> |
| <span class="source-line-no">314</span><span id="line-314"> } else {</span> |
| <span class="source-line-no">315</span><span id="line-315"> seekResult = NonLazyKeyValueScanner.doRealSeek(scanner, seekKey, forward);</span> |
| <span class="source-line-no">316</span><span id="line-316"> }</span> |
| <span class="source-line-no">317</span><span id="line-317"></span> |
| <span class="source-line-no">318</span><span id="line-318"> if (!seekResult) {</span> |
| <span class="source-line-no">319</span><span id="line-319"> this.scannersForDelayedClose.add(scanner);</span> |
| <span class="source-line-no">320</span><span id="line-320"> } else {</span> |
| <span class="source-line-no">321</span><span id="line-321"> heap.add(scanner);</span> |
| <span class="source-line-no">322</span><span id="line-322"> }</span> |
| <span class="source-line-no">323</span><span id="line-323"> scanner = heap.poll();</span> |
| <span class="source-line-no">324</span><span id="line-324"> if (scanner == null) {</span> |
| <span class="source-line-no">325</span><span id="line-325"> current = null;</span> |
| <span class="source-line-no">326</span><span id="line-326"> }</span> |
| <span class="source-line-no">327</span><span id="line-327"> }</span> |
| <span class="source-line-no">328</span><span id="line-328"> } catch (Exception e) {</span> |
| <span class="source-line-no">329</span><span id="line-329"> if (scanner != null) {</span> |
| <span class="source-line-no">330</span><span id="line-330"> try {</span> |
| <span class="source-line-no">331</span><span id="line-331"> scanner.close();</span> |
| <span class="source-line-no">332</span><span id="line-332"> } catch (Exception ce) {</span> |
| <span class="source-line-no">333</span><span id="line-333"> LOG.warn("close KeyValueScanner error", ce);</span> |
| <span class="source-line-no">334</span><span id="line-334"> }</span> |
| <span class="source-line-no">335</span><span id="line-335"> }</span> |
| <span class="source-line-no">336</span><span id="line-336"> throw e;</span> |
| <span class="source-line-no">337</span><span id="line-337"> }</span> |
| <span class="source-line-no">338</span><span id="line-338"></span> |
| <span class="source-line-no">339</span><span id="line-339"> // Heap is returning empty, scanner is done</span> |
| <span class="source-line-no">340</span><span id="line-340"> return false;</span> |
| <span class="source-line-no">341</span><span id="line-341"> }</span> |
| <span class="source-line-no">342</span><span id="line-342"></span> |
| <span class="source-line-no">343</span><span id="line-343"> /**</span> |
| <span class="source-line-no">344</span><span id="line-344"> * Fetches the top sub-scanner from the priority queue, ensuring that a real seek has been done on</span> |
| <span class="source-line-no">345</span><span id="line-345"> * it. Works by fetching the top sub-scanner, and if it has not done a real seek, making it do so</span> |
| <span class="source-line-no">346</span><span id="line-346"> * (which will modify its top KV), putting it back, and repeating this until success. Relies on</span> |
| <span class="source-line-no">347</span><span id="line-347"> * the fact that on a lazy seek we set the current key of a StoreFileScanner to a KV that is not</span> |
| <span class="source-line-no">348</span><span id="line-348"> * greater than the real next KV to be read from that file, so the scanner that bubbles up to the</span> |
| <span class="source-line-no">349</span><span id="line-349"> * top of the heap will have global next KV in this scanner heap if (1) it has done a real seek</span> |
| <span class="source-line-no">350</span><span id="line-350"> * and (2) its KV is the top among all top KVs (some of which are fake) in the scanner heap.</span> |
| <span class="source-line-no">351</span><span id="line-351"> */</span> |
| <span class="source-line-no">352</span><span id="line-352"> protected KeyValueScanner pollRealKV() throws IOException {</span> |
| <span class="source-line-no">353</span><span id="line-353"> KeyValueScanner kvScanner = heap.poll();</span> |
| <span class="source-line-no">354</span><span id="line-354"> if (kvScanner == null) {</span> |
| <span class="source-line-no">355</span><span id="line-355"> return null;</span> |
| <span class="source-line-no">356</span><span id="line-356"> }</span> |
| <span class="source-line-no">357</span><span id="line-357"></span> |
| <span class="source-line-no">358</span><span id="line-358"> while (kvScanner != null && !kvScanner.realSeekDone()) {</span> |
| <span class="source-line-no">359</span><span id="line-359"> if (kvScanner.peek() != null) {</span> |
| <span class="source-line-no">360</span><span id="line-360"> try {</span> |
| <span class="source-line-no">361</span><span id="line-361"> kvScanner.enforceSeek();</span> |
| <span class="source-line-no">362</span><span id="line-362"> } catch (IOException ioe) {</span> |
| <span class="source-line-no">363</span><span id="line-363"> // Add the item to delayed close set in case it is leak from close</span> |
| <span class="source-line-no">364</span><span id="line-364"> this.scannersForDelayedClose.add(kvScanner);</span> |
| <span class="source-line-no">365</span><span id="line-365"> throw ioe;</span> |
| <span class="source-line-no">366</span><span id="line-366"> }</span> |
| <span class="source-line-no">367</span><span id="line-367"> Cell curKV = kvScanner.peek();</span> |
| <span class="source-line-no">368</span><span id="line-368"> if (curKV != null) {</span> |
| <span class="source-line-no">369</span><span id="line-369"> KeyValueScanner nextEarliestScanner = heap.peek();</span> |
| <span class="source-line-no">370</span><span id="line-370"> if (nextEarliestScanner == null) {</span> |
| <span class="source-line-no">371</span><span id="line-371"> // The heap is empty. Return the only possible scanner.</span> |
| <span class="source-line-no">372</span><span id="line-372"> return kvScanner;</span> |
| <span class="source-line-no">373</span><span id="line-373"> }</span> |
| <span class="source-line-no">374</span><span id="line-374"></span> |
| <span class="source-line-no">375</span><span id="line-375"> // Compare the current scanner to the next scanner. We try to avoid</span> |
| <span class="source-line-no">376</span><span id="line-376"> // putting the current one back into the heap if possible.</span> |
| <span class="source-line-no">377</span><span id="line-377"> Cell nextKV = nextEarliestScanner.peek();</span> |
| <span class="source-line-no">378</span><span id="line-378"> if (nextKV == null || comparator.compare(curKV, nextKV) < 0) {</span> |
| <span class="source-line-no">379</span><span id="line-379"> // We already have the scanner with the earliest KV, so return it.</span> |
| <span class="source-line-no">380</span><span id="line-380"> return kvScanner;</span> |
| <span class="source-line-no">381</span><span id="line-381"> }</span> |
| <span class="source-line-no">382</span><span id="line-382"></span> |
| <span class="source-line-no">383</span><span id="line-383"> // Otherwise, put the scanner back into the heap and let it compete</span> |
| <span class="source-line-no">384</span><span id="line-384"> // against all other scanners (both those that have done a "real</span> |
| <span class="source-line-no">385</span><span id="line-385"> // seek" and a "lazy seek").</span> |
| <span class="source-line-no">386</span><span id="line-386"> heap.add(kvScanner);</span> |
| <span class="source-line-no">387</span><span id="line-387"> } else {</span> |
| <span class="source-line-no">388</span><span id="line-388"> // Close the scanner because we did a real seek and found out there</span> |
| <span class="source-line-no">389</span><span id="line-389"> // are no more KVs.</span> |
| <span class="source-line-no">390</span><span id="line-390"> this.scannersForDelayedClose.add(kvScanner);</span> |
| <span class="source-line-no">391</span><span id="line-391"> }</span> |
| <span class="source-line-no">392</span><span id="line-392"> } else {</span> |
| <span class="source-line-no">393</span><span id="line-393"> // Close the scanner because it has already run out of KVs even before</span> |
| <span class="source-line-no">394</span><span id="line-394"> // we had to do a real seek on it.</span> |
| <span class="source-line-no">395</span><span id="line-395"> this.scannersForDelayedClose.add(kvScanner);</span> |
| <span class="source-line-no">396</span><span id="line-396"> }</span> |
| <span class="source-line-no">397</span><span id="line-397"> kvScanner = heap.poll();</span> |
| <span class="source-line-no">398</span><span id="line-398"> }</span> |
| <span class="source-line-no">399</span><span id="line-399"></span> |
| <span class="source-line-no">400</span><span id="line-400"> return kvScanner;</span> |
| <span class="source-line-no">401</span><span id="line-401"> }</span> |
| <span class="source-line-no">402</span><span id="line-402"></span> |
| <span class="source-line-no">403</span><span id="line-403"> /** Returns the current Heap */</span> |
| <span class="source-line-no">404</span><span id="line-404"> public PriorityQueue<KeyValueScanner> getHeap() {</span> |
| <span class="source-line-no">405</span><span id="line-405"> return this.heap;</span> |
| <span class="source-line-no">406</span><span id="line-406"> }</span> |
| <span class="source-line-no">407</span><span id="line-407"></span> |
| <span class="source-line-no">408</span><span id="line-408"> KeyValueScanner getCurrentForTesting() {</span> |
| <span class="source-line-no">409</span><span id="line-409"> return current;</span> |
| <span class="source-line-no">410</span><span id="line-410"> }</span> |
| <span class="source-line-no">411</span><span id="line-411"></span> |
| <span class="source-line-no">412</span><span id="line-412"> @Override</span> |
| <span class="source-line-no">413</span><span id="line-413"> public ExtendedCell getNextIndexedKey() {</span> |
| <span class="source-line-no">414</span><span id="line-414"> // here we return the next index key from the top scanner</span> |
| <span class="source-line-no">415</span><span id="line-415"> return current == null ? null : current.getNextIndexedKey();</span> |
| <span class="source-line-no">416</span><span id="line-416"> }</span> |
| <span class="source-line-no">417</span><span id="line-417"></span> |
| <span class="source-line-no">418</span><span id="line-418"> @Override</span> |
| <span class="source-line-no">419</span><span id="line-419"> public void shipped() throws IOException {</span> |
| <span class="source-line-no">420</span><span id="line-420"> for (KeyValueScanner scanner : this.scannersForDelayedClose) {</span> |
| <span class="source-line-no">421</span><span id="line-421"> scanner.close(); // There wont be further fetch of Cells from these scanners. Just close.</span> |
| <span class="source-line-no">422</span><span id="line-422"> }</span> |
| <span class="source-line-no">423</span><span id="line-423"> this.scannersForDelayedClose.clear();</span> |
| <span class="source-line-no">424</span><span id="line-424"> if (this.current != null) {</span> |
| <span class="source-line-no">425</span><span id="line-425"> this.current.shipped();</span> |
| <span class="source-line-no">426</span><span id="line-426"> }</span> |
| <span class="source-line-no">427</span><span id="line-427"> if (this.heap != null) {</span> |
| <span class="source-line-no">428</span><span id="line-428"> for (KeyValueScanner scanner : this.heap) {</span> |
| <span class="source-line-no">429</span><span id="line-429"> scanner.shipped();</span> |
| <span class="source-line-no">430</span><span id="line-430"> }</span> |
| <span class="source-line-no">431</span><span id="line-431"> }</span> |
| <span class="source-line-no">432</span><span id="line-432"> }</span> |
| <span class="source-line-no">433</span><span id="line-433">}</span> |
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| </main> |
| </body> |
| </html> |
