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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.regionserver;<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.util.Iterator;<a name="line.21"></a> |
| <span class="sourceLineNo">022</span>import java.util.SortedSet;<a name="line.22"></a> |
| <span class="sourceLineNo">023</span>import org.apache.commons.lang3.NotImplementedException;<a name="line.23"></a> |
| <span class="sourceLineNo">024</span>import org.apache.hadoop.fs.Path;<a name="line.24"></a> |
| <span class="sourceLineNo">025</span>import org.apache.hadoop.hbase.Cell;<a name="line.25"></a> |
| <span class="sourceLineNo">026</span>import org.apache.hadoop.hbase.PrivateCellUtil;<a name="line.26"></a> |
| <span class="sourceLineNo">027</span>import org.apache.hadoop.hbase.client.Scan;<a name="line.27"></a> |
| <span class="sourceLineNo">028</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.28"></a> |
| <span class="sourceLineNo">029</span><a name="line.29"></a> |
| <span class="sourceLineNo">030</span>/**<a name="line.30"></a> |
| <span class="sourceLineNo">031</span> * A scanner of a single memstore segment.<a name="line.31"></a> |
| <span class="sourceLineNo">032</span> */<a name="line.32"></a> |
| <span class="sourceLineNo">033</span>@InterfaceAudience.Private<a name="line.33"></a> |
| <span class="sourceLineNo">034</span>public class SegmentScanner implements KeyValueScanner {<a name="line.34"></a> |
| <span class="sourceLineNo">035</span><a name="line.35"></a> |
| <span class="sourceLineNo">036</span> // the observed structure<a name="line.36"></a> |
| <span class="sourceLineNo">037</span> protected final Segment segment;<a name="line.37"></a> |
| <span class="sourceLineNo">038</span> // the highest relevant MVCC<a name="line.38"></a> |
| <span class="sourceLineNo">039</span> private long readPoint;<a name="line.39"></a> |
| <span class="sourceLineNo">040</span> // the current iterator that can be reinitialized by<a name="line.40"></a> |
| <span class="sourceLineNo">041</span> // seek(), backwardSeek(), or reseek()<a name="line.41"></a> |
| <span class="sourceLineNo">042</span> protected Iterator<Cell> iter;<a name="line.42"></a> |
| <span class="sourceLineNo">043</span> // the pre-calculated cell to be returned by peek()<a name="line.43"></a> |
| <span class="sourceLineNo">044</span> protected Cell current = null;<a name="line.44"></a> |
| <span class="sourceLineNo">045</span> // or next()<a name="line.45"></a> |
| <span class="sourceLineNo">046</span> // A flag represents whether could stop skipping KeyValues for MVCC<a name="line.46"></a> |
| <span class="sourceLineNo">047</span> // if have encountered the next row. Only used for reversed scan<a name="line.47"></a> |
| <span class="sourceLineNo">048</span> private boolean stopSkippingKVsIfNextRow = false;<a name="line.48"></a> |
| <span class="sourceLineNo">049</span> // Stop skipping KeyValues for MVCC if finish this row. Only used for reversed scan<a name="line.49"></a> |
| <span class="sourceLineNo">050</span> private Cell stopSkippingKVsRow;<a name="line.50"></a> |
| <span class="sourceLineNo">051</span> // last iterated KVs by seek (to restore the iterator state after reseek)<a name="line.51"></a> |
| <span class="sourceLineNo">052</span> private Cell last = null;<a name="line.52"></a> |
| <span class="sourceLineNo">053</span><a name="line.53"></a> |
| <span class="sourceLineNo">054</span> // flag to indicate if this scanner is closed<a name="line.54"></a> |
| <span class="sourceLineNo">055</span> protected boolean closed = false;<a name="line.55"></a> |
| <span class="sourceLineNo">056</span><a name="line.56"></a> |
| <span class="sourceLineNo">057</span> /**<a name="line.57"></a> |
| <span class="sourceLineNo">058</span> * Scanners are ordered from 0 (oldest) to newest in increasing order.<a name="line.58"></a> |
| <span class="sourceLineNo">059</span> */<a name="line.59"></a> |
| <span class="sourceLineNo">060</span> protected SegmentScanner(Segment segment, long readPoint) {<a name="line.60"></a> |
| <span class="sourceLineNo">061</span> this.segment = segment;<a name="line.61"></a> |
| <span class="sourceLineNo">062</span> this.readPoint = readPoint;<a name="line.62"></a> |
| <span class="sourceLineNo">063</span> // increase the reference count so the underlying structure will not be de-allocated<a name="line.63"></a> |
| <span class="sourceLineNo">064</span> this.segment.incScannerCount();<a name="line.64"></a> |
| <span class="sourceLineNo">065</span> iter = segment.iterator();<a name="line.65"></a> |
| <span class="sourceLineNo">066</span> // the initialization of the current is required for working with heap of SegmentScanners<a name="line.66"></a> |
| <span class="sourceLineNo">067</span> updateCurrent();<a name="line.67"></a> |
| <span class="sourceLineNo">068</span> if (current == null) {<a name="line.68"></a> |
| <span class="sourceLineNo">069</span> // nothing to fetch from this scanner<a name="line.69"></a> |
| <span class="sourceLineNo">070</span> close();<a name="line.70"></a> |
| <span class="sourceLineNo">071</span> }<a name="line.71"></a> |
| <span class="sourceLineNo">072</span> }<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> * Look at the next Cell in this scanner, but do not iterate the scanner<a name="line.75"></a> |
| <span class="sourceLineNo">076</span> * @return the currently observed Cell<a name="line.76"></a> |
| <span class="sourceLineNo">077</span> */<a name="line.77"></a> |
| <span class="sourceLineNo">078</span> @Override<a name="line.78"></a> |
| <span class="sourceLineNo">079</span> public Cell peek() { // sanity check, the current should be always valid<a name="line.79"></a> |
| <span class="sourceLineNo">080</span> if (closed) {<a name="line.80"></a> |
| <span class="sourceLineNo">081</span> return null;<a name="line.81"></a> |
| <span class="sourceLineNo">082</span> }<a name="line.82"></a> |
| <span class="sourceLineNo">083</span> if (current != null && current.getSequenceId() > readPoint) {<a name="line.83"></a> |
| <span class="sourceLineNo">084</span> throw new RuntimeException("current is invalid: read point is " + readPoint + ", "<a name="line.84"></a> |
| <span class="sourceLineNo">085</span> + "while current sequence id is " + current.getSequenceId());<a name="line.85"></a> |
| <span class="sourceLineNo">086</span> }<a name="line.86"></a> |
| <span class="sourceLineNo">087</span> return current;<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> /**<a name="line.90"></a> |
| <span class="sourceLineNo">091</span> * Return the next Cell in this scanner, iterating the scanner<a name="line.91"></a> |
| <span class="sourceLineNo">092</span> * @return the next Cell or null if end of scanner<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 Cell next() throws IOException {<a name="line.95"></a> |
| <span class="sourceLineNo">096</span> if (closed) {<a name="line.96"></a> |
| <span class="sourceLineNo">097</span> return null;<a name="line.97"></a> |
| <span class="sourceLineNo">098</span> }<a name="line.98"></a> |
| <span class="sourceLineNo">099</span> Cell oldCurrent = current;<a name="line.99"></a> |
| <span class="sourceLineNo">100</span> updateCurrent(); // update the currently observed Cell<a name="line.100"></a> |
| <span class="sourceLineNo">101</span> return oldCurrent;<a name="line.101"></a> |
| <span class="sourceLineNo">102</span> }<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> * Seek the scanner at or after the specified Cell.<a name="line.105"></a> |
| <span class="sourceLineNo">106</span> * @param cell seek value<a name="line.106"></a> |
| <span class="sourceLineNo">107</span> * @return true if scanner has values left, false if end of scanner<a name="line.107"></a> |
| <span class="sourceLineNo">108</span> */<a name="line.108"></a> |
| <span class="sourceLineNo">109</span> @Override<a name="line.109"></a> |
| <span class="sourceLineNo">110</span> public boolean seek(Cell cell) throws IOException {<a name="line.110"></a> |
| <span class="sourceLineNo">111</span> if (closed) {<a name="line.111"></a> |
| <span class="sourceLineNo">112</span> return false;<a name="line.112"></a> |
| <span class="sourceLineNo">113</span> }<a name="line.113"></a> |
| <span class="sourceLineNo">114</span> if (cell == null) {<a name="line.114"></a> |
| <span class="sourceLineNo">115</span> close();<a name="line.115"></a> |
| <span class="sourceLineNo">116</span> return false;<a name="line.116"></a> |
| <span class="sourceLineNo">117</span> }<a name="line.117"></a> |
| <span class="sourceLineNo">118</span> // restart the iterator from new key<a name="line.118"></a> |
| <span class="sourceLineNo">119</span> iter = getIterator(cell);<a name="line.119"></a> |
| <span class="sourceLineNo">120</span> // last is going to be reinitialized in the next getNext() call<a name="line.120"></a> |
| <span class="sourceLineNo">121</span> last = null;<a name="line.121"></a> |
| <span class="sourceLineNo">122</span> updateCurrent();<a name="line.122"></a> |
| <span class="sourceLineNo">123</span> return (current != null);<a name="line.123"></a> |
| <span class="sourceLineNo">124</span> }<a name="line.124"></a> |
| <span class="sourceLineNo">125</span><a name="line.125"></a> |
| <span class="sourceLineNo">126</span> protected Iterator<Cell> getIterator(Cell cell) {<a name="line.126"></a> |
| <span class="sourceLineNo">127</span> return segment.tailSet(cell).iterator();<a name="line.127"></a> |
| <span class="sourceLineNo">128</span> }<a name="line.128"></a> |
| <span class="sourceLineNo">129</span><a name="line.129"></a> |
| <span class="sourceLineNo">130</span> /**<a name="line.130"></a> |
| <span class="sourceLineNo">131</span> * Reseek the scanner at or after the specified KeyValue. This method is guaranteed to seek at or<a name="line.131"></a> |
| <span class="sourceLineNo">132</span> * after the required key only if the key comes after the current position of the scanner. Should<a name="line.132"></a> |
| <span class="sourceLineNo">133</span> * not be used to seek to a key which may come before the current position.<a name="line.133"></a> |
| <span class="sourceLineNo">134</span> * @param cell seek value (should be non-null)<a name="line.134"></a> |
| <span class="sourceLineNo">135</span> * @return true if scanner has values left, false if end of scanner<a name="line.135"></a> |
| <span class="sourceLineNo">136</span> */<a name="line.136"></a> |
| <span class="sourceLineNo">137</span> @Override<a name="line.137"></a> |
| <span class="sourceLineNo">138</span> public boolean reseek(Cell cell) throws IOException {<a name="line.138"></a> |
| <span class="sourceLineNo">139</span> if (closed) {<a name="line.139"></a> |
| <span class="sourceLineNo">140</span> return false;<a name="line.140"></a> |
| <span class="sourceLineNo">141</span> }<a name="line.141"></a> |
| <span class="sourceLineNo">142</span> /*<a name="line.142"></a> |
| <span class="sourceLineNo">143</span> * See HBASE-4195 & HBASE-3855 & HBASE-6591 for the background on this implementation. This code<a name="line.143"></a> |
| <span class="sourceLineNo">144</span> * is executed concurrently with flush and puts, without locks. The ideal implementation for<a name="line.144"></a> |
| <span class="sourceLineNo">145</span> * performance would use the sub skip list implicitly pointed by the iterator. Unfortunately the<a name="line.145"></a> |
| <span class="sourceLineNo">146</span> * Java API does not offer a method to get it. So we remember the last keys we iterated to and<a name="line.146"></a> |
| <span class="sourceLineNo">147</span> * restore the reseeked set to at least that point.<a name="line.147"></a> |
| <span class="sourceLineNo">148</span> */<a name="line.148"></a> |
| <span class="sourceLineNo">149</span> iter = getIterator(getHighest(cell, last));<a name="line.149"></a> |
| <span class="sourceLineNo">150</span> updateCurrent();<a name="line.150"></a> |
| <span class="sourceLineNo">151</span> return (current != null);<a name="line.151"></a> |
| <span class="sourceLineNo">152</span> }<a name="line.152"></a> |
| <span class="sourceLineNo">153</span><a name="line.153"></a> |
| <span class="sourceLineNo">154</span> /**<a name="line.154"></a> |
| <span class="sourceLineNo">155</span> * Seek the scanner at or before the row of specified Cell, it firstly tries to seek the scanner<a name="line.155"></a> |
| <span class="sourceLineNo">156</span> * at or after the specified Cell, return if peek KeyValue of scanner has the same row with<a name="line.156"></a> |
| <span class="sourceLineNo">157</span> * specified Cell, otherwise seek the scanner at the first Cell of the row which is the previous<a name="line.157"></a> |
| <span class="sourceLineNo">158</span> * row of specified KeyValue<a name="line.158"></a> |
| <span class="sourceLineNo">159</span> * @param key seek Cell<a name="line.159"></a> |
| <span class="sourceLineNo">160</span> * @return true if the scanner is at the valid KeyValue, false if such Cell does not exist<a name="line.160"></a> |
| <span class="sourceLineNo">161</span> */<a name="line.161"></a> |
| <span class="sourceLineNo">162</span> @Override<a name="line.162"></a> |
| <span class="sourceLineNo">163</span> public boolean backwardSeek(Cell key) throws IOException {<a name="line.163"></a> |
| <span class="sourceLineNo">164</span> if (closed) {<a name="line.164"></a> |
| <span class="sourceLineNo">165</span> return false;<a name="line.165"></a> |
| <span class="sourceLineNo">166</span> }<a name="line.166"></a> |
| <span class="sourceLineNo">167</span> seek(key); // seek forward then go backward<a name="line.167"></a> |
| <span class="sourceLineNo">168</span> if (peek() == null || segment.compareRows(peek(), key) > 0) {<a name="line.168"></a> |
| <span class="sourceLineNo">169</span> return seekToPreviousRow(key);<a name="line.169"></a> |
| <span class="sourceLineNo">170</span> }<a name="line.170"></a> |
| <span class="sourceLineNo">171</span> return true;<a name="line.171"></a> |
| <span class="sourceLineNo">172</span> }<a name="line.172"></a> |
| <span class="sourceLineNo">173</span><a name="line.173"></a> |
| <span class="sourceLineNo">174</span> /**<a name="line.174"></a> |
| <span class="sourceLineNo">175</span> * Seek the scanner at the first Cell of the row which is the previous row of specified key<a name="line.175"></a> |
| <span class="sourceLineNo">176</span> * @param cell seek value<a name="line.176"></a> |
| <span class="sourceLineNo">177</span> * @return true if the scanner at the first valid Cell of previous row, false if not existing such<a name="line.177"></a> |
| <span class="sourceLineNo">178</span> * Cell<a name="line.178"></a> |
| <span class="sourceLineNo">179</span> */<a name="line.179"></a> |
| <span class="sourceLineNo">180</span> @Override<a name="line.180"></a> |
| <span class="sourceLineNo">181</span> public boolean seekToPreviousRow(Cell cell) throws IOException {<a name="line.181"></a> |
| <span class="sourceLineNo">182</span> if (closed) {<a name="line.182"></a> |
| <span class="sourceLineNo">183</span> return false;<a name="line.183"></a> |
| <span class="sourceLineNo">184</span> }<a name="line.184"></a> |
| <span class="sourceLineNo">185</span> boolean keepSeeking;<a name="line.185"></a> |
| <span class="sourceLineNo">186</span> Cell key = cell;<a name="line.186"></a> |
| <span class="sourceLineNo">187</span> do {<a name="line.187"></a> |
| <span class="sourceLineNo">188</span> Cell firstKeyOnRow = PrivateCellUtil.createFirstOnRow(key);<a name="line.188"></a> |
| <span class="sourceLineNo">189</span> SortedSet<Cell> cellHead = segment.headSet(firstKeyOnRow);<a name="line.189"></a> |
| <span class="sourceLineNo">190</span> Cell lastCellBeforeRow = cellHead.isEmpty() ? null : cellHead.last();<a name="line.190"></a> |
| <span class="sourceLineNo">191</span> if (lastCellBeforeRow == null) {<a name="line.191"></a> |
| <span class="sourceLineNo">192</span> current = null;<a name="line.192"></a> |
| <span class="sourceLineNo">193</span> return false;<a name="line.193"></a> |
| <span class="sourceLineNo">194</span> }<a name="line.194"></a> |
| <span class="sourceLineNo">195</span> Cell firstKeyOnPreviousRow = PrivateCellUtil.createFirstOnRow(lastCellBeforeRow);<a name="line.195"></a> |
| <span class="sourceLineNo">196</span> this.stopSkippingKVsIfNextRow = true;<a name="line.196"></a> |
| <span class="sourceLineNo">197</span> this.stopSkippingKVsRow = firstKeyOnPreviousRow;<a name="line.197"></a> |
| <span class="sourceLineNo">198</span> seek(firstKeyOnPreviousRow);<a name="line.198"></a> |
| <span class="sourceLineNo">199</span> this.stopSkippingKVsIfNextRow = false;<a name="line.199"></a> |
| <span class="sourceLineNo">200</span> if (<a name="line.200"></a> |
| <span class="sourceLineNo">201</span> peek() == null || segment.getComparator().compareRows(peek(), firstKeyOnPreviousRow) > 0<a name="line.201"></a> |
| <span class="sourceLineNo">202</span> ) {<a name="line.202"></a> |
| <span class="sourceLineNo">203</span> keepSeeking = true;<a name="line.203"></a> |
| <span class="sourceLineNo">204</span> key = firstKeyOnPreviousRow;<a name="line.204"></a> |
| <span class="sourceLineNo">205</span> continue;<a name="line.205"></a> |
| <span class="sourceLineNo">206</span> } else {<a name="line.206"></a> |
| <span class="sourceLineNo">207</span> keepSeeking = false;<a name="line.207"></a> |
| <span class="sourceLineNo">208</span> }<a name="line.208"></a> |
| <span class="sourceLineNo">209</span> } while (keepSeeking);<a name="line.209"></a> |
| <span class="sourceLineNo">210</span> return true;<a name="line.210"></a> |
| <span class="sourceLineNo">211</span> }<a name="line.211"></a> |
| <span class="sourceLineNo">212</span><a name="line.212"></a> |
| <span class="sourceLineNo">213</span> /**<a name="line.213"></a> |
| <span class="sourceLineNo">214</span> * Seek the scanner at the first KeyValue of last row<a name="line.214"></a> |
| <span class="sourceLineNo">215</span> * @return true if scanner has values left, false if the underlying data is empty<a name="line.215"></a> |
| <span class="sourceLineNo">216</span> */<a name="line.216"></a> |
| <span class="sourceLineNo">217</span> @Override<a name="line.217"></a> |
| <span class="sourceLineNo">218</span> public boolean seekToLastRow() throws IOException {<a name="line.218"></a> |
| <span class="sourceLineNo">219</span> if (closed) {<a name="line.219"></a> |
| <span class="sourceLineNo">220</span> return false;<a name="line.220"></a> |
| <span class="sourceLineNo">221</span> }<a name="line.221"></a> |
| <span class="sourceLineNo">222</span> Cell higherCell = segment.isEmpty() ? null : segment.last();<a name="line.222"></a> |
| <span class="sourceLineNo">223</span> if (higherCell == null) {<a name="line.223"></a> |
| <span class="sourceLineNo">224</span> return false;<a name="line.224"></a> |
| <span class="sourceLineNo">225</span> }<a name="line.225"></a> |
| <span class="sourceLineNo">226</span><a name="line.226"></a> |
| <span class="sourceLineNo">227</span> Cell firstCellOnLastRow = PrivateCellUtil.createFirstOnRow(higherCell);<a name="line.227"></a> |
| <span class="sourceLineNo">228</span><a name="line.228"></a> |
| <span class="sourceLineNo">229</span> if (seek(firstCellOnLastRow)) {<a name="line.229"></a> |
| <span class="sourceLineNo">230</span> return true;<a name="line.230"></a> |
| <span class="sourceLineNo">231</span> } else {<a name="line.231"></a> |
| <span class="sourceLineNo">232</span> return seekToPreviousRow(higherCell);<a name="line.232"></a> |
| <span class="sourceLineNo">233</span> }<a name="line.233"></a> |
| <span class="sourceLineNo">234</span> }<a name="line.234"></a> |
| <span class="sourceLineNo">235</span><a name="line.235"></a> |
| <span class="sourceLineNo">236</span> /**<a name="line.236"></a> |
| <span class="sourceLineNo">237</span> * Close the KeyValue scanner.<a name="line.237"></a> |
| <span class="sourceLineNo">238</span> */<a name="line.238"></a> |
| <span class="sourceLineNo">239</span> @Override<a name="line.239"></a> |
| <span class="sourceLineNo">240</span> public void close() {<a name="line.240"></a> |
| <span class="sourceLineNo">241</span> if (closed) {<a name="line.241"></a> |
| <span class="sourceLineNo">242</span> return;<a name="line.242"></a> |
| <span class="sourceLineNo">243</span> }<a name="line.243"></a> |
| <span class="sourceLineNo">244</span> getSegment().decScannerCount();<a name="line.244"></a> |
| <span class="sourceLineNo">245</span> closed = true;<a name="line.245"></a> |
| <span class="sourceLineNo">246</span> }<a name="line.246"></a> |
| <span class="sourceLineNo">247</span><a name="line.247"></a> |
| <span class="sourceLineNo">248</span> /**<a name="line.248"></a> |
| <span class="sourceLineNo">249</span> * This functionality should be resolved in the higher level which is MemStoreScanner, currently<a name="line.249"></a> |
| <span class="sourceLineNo">250</span> * returns true as default. Doesn't throw IllegalStateException in order not to change the<a name="line.250"></a> |
| <span class="sourceLineNo">251</span> * signature of the overridden method<a name="line.251"></a> |
| <span class="sourceLineNo">252</span> */<a name="line.252"></a> |
| <span class="sourceLineNo">253</span> @Override<a name="line.253"></a> |
| <span class="sourceLineNo">254</span> public boolean shouldUseScanner(Scan scan, HStore store, long oldestUnexpiredTS) {<a name="line.254"></a> |
| <span class="sourceLineNo">255</span> return getSegment().shouldSeek(scan.getColumnFamilyTimeRange().getOrDefault(<a name="line.255"></a> |
| <span class="sourceLineNo">256</span> store.getColumnFamilyDescriptor().getName(), scan.getTimeRange()), oldestUnexpiredTS);<a name="line.256"></a> |
| <span class="sourceLineNo">257</span> }<a name="line.257"></a> |
| <span class="sourceLineNo">258</span><a name="line.258"></a> |
| <span class="sourceLineNo">259</span> @Override<a name="line.259"></a> |
| <span class="sourceLineNo">260</span> public boolean requestSeek(Cell c, boolean forward, boolean useBloom) throws IOException {<a name="line.260"></a> |
| <span class="sourceLineNo">261</span> return NonLazyKeyValueScanner.doRealSeek(this, c, forward);<a name="line.261"></a> |
| <span class="sourceLineNo">262</span> }<a name="line.262"></a> |
| <span class="sourceLineNo">263</span><a name="line.263"></a> |
| <span class="sourceLineNo">264</span> /**<a name="line.264"></a> |
| <span class="sourceLineNo">265</span> * This scanner is working solely on the in-memory MemStore and doesn't work on store files,<a name="line.265"></a> |
| <span class="sourceLineNo">266</span> * MutableCellSetSegmentScanner always does the seek, therefore always returning true.<a name="line.266"></a> |
| <span class="sourceLineNo">267</span> */<a name="line.267"></a> |
| <span class="sourceLineNo">268</span> @Override<a name="line.268"></a> |
| <span class="sourceLineNo">269</span> public boolean realSeekDone() {<a name="line.269"></a> |
| <span class="sourceLineNo">270</span> return true;<a name="line.270"></a> |
| <span class="sourceLineNo">271</span> }<a name="line.271"></a> |
| <span class="sourceLineNo">272</span><a name="line.272"></a> |
| <span class="sourceLineNo">273</span> /**<a name="line.273"></a> |
| <span class="sourceLineNo">274</span> * This function should be never called on scanners that always do real seek operations (i.e. most<a name="line.274"></a> |
| <span class="sourceLineNo">275</span> * of the scanners and also this one). The easiest way to achieve this is to call<a name="line.275"></a> |
| <span class="sourceLineNo">276</span> * {@link #realSeekDone()} first.<a name="line.276"></a> |
| <span class="sourceLineNo">277</span> */<a name="line.277"></a> |
| <span class="sourceLineNo">278</span> @Override<a name="line.278"></a> |
| <span class="sourceLineNo">279</span> public void enforceSeek() throws IOException {<a name="line.279"></a> |
| <span class="sourceLineNo">280</span> throw new NotImplementedException("enforceSeek cannot be called on a SegmentScanner");<a name="line.280"></a> |
| <span class="sourceLineNo">281</span> }<a name="line.281"></a> |
| <span class="sourceLineNo">282</span><a name="line.282"></a> |
| <span class="sourceLineNo">283</span> /** Returns true if this is a file scanner. Otherwise a memory scanner is assumed. */<a name="line.283"></a> |
| <span class="sourceLineNo">284</span> @Override<a name="line.284"></a> |
| <span class="sourceLineNo">285</span> public boolean isFileScanner() {<a name="line.285"></a> |
| <span class="sourceLineNo">286</span> return false;<a name="line.286"></a> |
| <span class="sourceLineNo">287</span> }<a name="line.287"></a> |
| <span class="sourceLineNo">288</span><a name="line.288"></a> |
| <span class="sourceLineNo">289</span> @Override<a name="line.289"></a> |
| <span class="sourceLineNo">290</span> public Path getFilePath() {<a name="line.290"></a> |
| <span class="sourceLineNo">291</span> return null;<a name="line.291"></a> |
| <span class="sourceLineNo">292</span> }<a name="line.292"></a> |
| <span class="sourceLineNo">293</span><a name="line.293"></a> |
| <span class="sourceLineNo">294</span> /**<a name="line.294"></a> |
| <span class="sourceLineNo">295</span> * @return the next key in the index (the key to seek to the next block) if known, or null<a name="line.295"></a> |
| <span class="sourceLineNo">296</span> * otherwise Not relevant for in-memory scanner<a name="line.296"></a> |
| <span class="sourceLineNo">297</span> */<a name="line.297"></a> |
| <span class="sourceLineNo">298</span> @Override<a name="line.298"></a> |
| <span class="sourceLineNo">299</span> public Cell getNextIndexedKey() {<a name="line.299"></a> |
| <span class="sourceLineNo">300</span> return null;<a name="line.300"></a> |
| <span class="sourceLineNo">301</span> }<a name="line.301"></a> |
| <span class="sourceLineNo">302</span><a name="line.302"></a> |
| <span class="sourceLineNo">303</span> /**<a name="line.303"></a> |
| <span class="sourceLineNo">304</span> * Called after a batch of rows scanned (RPC) and set to be returned to client. Any in between<a name="line.304"></a> |
| <span class="sourceLineNo">305</span> * cleanup can be done here. Nothing to be done for MutableCellSetSegmentScanner.<a name="line.305"></a> |
| <span class="sourceLineNo">306</span> */<a name="line.306"></a> |
| <span class="sourceLineNo">307</span> @Override<a name="line.307"></a> |
| <span class="sourceLineNo">308</span> public void shipped() throws IOException {<a name="line.308"></a> |
| <span class="sourceLineNo">309</span> // do nothing<a name="line.309"></a> |
| <span class="sourceLineNo">310</span> }<a name="line.310"></a> |
| <span class="sourceLineNo">311</span><a name="line.311"></a> |
| <span class="sourceLineNo">312</span> // debug method<a name="line.312"></a> |
| <span class="sourceLineNo">313</span> @Override<a name="line.313"></a> |
| <span class="sourceLineNo">314</span> public String toString() {<a name="line.314"></a> |
| <span class="sourceLineNo">315</span> String res = "Store segment scanner of type " + this.getClass().getName() + "; ";<a name="line.315"></a> |
| <span class="sourceLineNo">316</span> res += "Scanner order " + getScannerOrder() + "; ";<a name="line.316"></a> |
| <span class="sourceLineNo">317</span> res += getSegment().toString();<a name="line.317"></a> |
| <span class="sourceLineNo">318</span> return res;<a name="line.318"></a> |
| <span class="sourceLineNo">319</span> }<a name="line.319"></a> |
| <span class="sourceLineNo">320</span><a name="line.320"></a> |
| <span class="sourceLineNo">321</span> /********************* Private Methods **********************/<a name="line.321"></a> |
| <span class="sourceLineNo">322</span><a name="line.322"></a> |
| <span class="sourceLineNo">323</span> private Segment getSegment() {<a name="line.323"></a> |
| <span class="sourceLineNo">324</span> return segment;<a name="line.324"></a> |
| <span class="sourceLineNo">325</span> }<a name="line.325"></a> |
| <span class="sourceLineNo">326</span><a name="line.326"></a> |
| <span class="sourceLineNo">327</span> /**<a name="line.327"></a> |
| <span class="sourceLineNo">328</span> * Private internal method for iterating over the segment, skipping the cells with irrelevant MVCC<a name="line.328"></a> |
| <span class="sourceLineNo">329</span> */<a name="line.329"></a> |
| <span class="sourceLineNo">330</span> protected void updateCurrent() {<a name="line.330"></a> |
| <span class="sourceLineNo">331</span> Cell next = null;<a name="line.331"></a> |
| <span class="sourceLineNo">332</span><a name="line.332"></a> |
| <span class="sourceLineNo">333</span> try {<a name="line.333"></a> |
| <span class="sourceLineNo">334</span> while (iter.hasNext()) {<a name="line.334"></a> |
| <span class="sourceLineNo">335</span> next = iter.next();<a name="line.335"></a> |
| <span class="sourceLineNo">336</span> if (next.getSequenceId() <= this.readPoint) {<a name="line.336"></a> |
| <span class="sourceLineNo">337</span> current = next;<a name="line.337"></a> |
| <span class="sourceLineNo">338</span> return;// skip irrelevant versions<a name="line.338"></a> |
| <span class="sourceLineNo">339</span> }<a name="line.339"></a> |
| <span class="sourceLineNo">340</span> // for backwardSeek() stay in the boundaries of a single row<a name="line.340"></a> |
| <span class="sourceLineNo">341</span> if (stopSkippingKVsIfNextRow && segment.compareRows(next, stopSkippingKVsRow) > 0) {<a name="line.341"></a> |
| <span class="sourceLineNo">342</span> current = null;<a name="line.342"></a> |
| <span class="sourceLineNo">343</span> return;<a name="line.343"></a> |
| <span class="sourceLineNo">344</span> }<a name="line.344"></a> |
| <span class="sourceLineNo">345</span> } // end of while<a name="line.345"></a> |
| <span class="sourceLineNo">346</span><a name="line.346"></a> |
| <span class="sourceLineNo">347</span> current = null; // nothing found<a name="line.347"></a> |
| <span class="sourceLineNo">348</span> } finally {<a name="line.348"></a> |
| <span class="sourceLineNo">349</span> if (next != null) {<a name="line.349"></a> |
| <span class="sourceLineNo">350</span> // in all cases, remember the last KV we iterated to, needed for reseek()<a name="line.350"></a> |
| <span class="sourceLineNo">351</span> last = next;<a name="line.351"></a> |
| <span class="sourceLineNo">352</span> }<a name="line.352"></a> |
| <span class="sourceLineNo">353</span> }<a name="line.353"></a> |
| <span class="sourceLineNo">354</span> }<a name="line.354"></a> |
| <span class="sourceLineNo">355</span><a name="line.355"></a> |
| <span class="sourceLineNo">356</span> /**<a name="line.356"></a> |
| <span class="sourceLineNo">357</span> * Private internal method that returns the higher of the two key values, or null if they are both<a name="line.357"></a> |
| <span class="sourceLineNo">358</span> * null<a name="line.358"></a> |
| <span class="sourceLineNo">359</span> */<a name="line.359"></a> |
| <span class="sourceLineNo">360</span> private Cell getHighest(Cell first, Cell second) {<a name="line.360"></a> |
| <span class="sourceLineNo">361</span> if (first == null && second == null) {<a name="line.361"></a> |
| <span class="sourceLineNo">362</span> return null;<a name="line.362"></a> |
| <span class="sourceLineNo">363</span> }<a name="line.363"></a> |
| <span class="sourceLineNo">364</span> if (first != null && second != null) {<a name="line.364"></a> |
| <span class="sourceLineNo">365</span> int compare = segment.compare(first, second);<a name="line.365"></a> |
| <span class="sourceLineNo">366</span> return (compare > 0 ? first : second);<a name="line.366"></a> |
| <span class="sourceLineNo">367</span> }<a name="line.367"></a> |
| <span class="sourceLineNo">368</span> return (first != null ? first : second);<a name="line.368"></a> |
| <span class="sourceLineNo">369</span> }<a name="line.369"></a> |
| <span class="sourceLineNo">370</span>}<a name="line.370"></a> |
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| </pre> |
| </div> |
| </body> |
| </html> |
