| <!DOCTYPE HTML> |
| <html lang="en"> |
| <head> |
| <!-- Generated by javadoc (17) --> |
| <title>Source code</title> |
| <meta name="viewport" content="width=device-width, initial-scale=1"> |
| <meta name="description" content="source: package: org.apache.hadoop.hbase.io.hfile, class: LruCachedBlockQueue"> |
| <meta name="generator" content="javadoc/SourceToHTMLConverter"> |
| <link rel="stylesheet" type="text/css" href="../../../../../../../stylesheet.css" title="Style"> |
| </head> |
| <body class="source-page"> |
| <main role="main"> |
| <div class="source-container"> |
| <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.io.hfile;</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 org.apache.hadoop.hbase.io.HeapSize;</span> |
| <span class="source-line-no">021</span><span id="line-21">import org.apache.yetus.audience.InterfaceAudience;</span> |
| <span class="source-line-no">022</span><span id="line-22"></span> |
| <span class="source-line-no">023</span><span id="line-23">import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;</span> |
| <span class="source-line-no">024</span><span id="line-24">import org.apache.hbase.thirdparty.com.google.common.collect.MinMaxPriorityQueue;</span> |
| <span class="source-line-no">025</span><span id="line-25"></span> |
| <span class="source-line-no">026</span><span id="line-26">/**</span> |
| <span class="source-line-no">027</span><span id="line-27"> * A memory-bound queue that will grow until an element brings total size &gt;= maxSize. From then</span> |
| <span class="source-line-no">028</span><span id="line-28"> * on, only entries that are sorted larger than the smallest current entry will be</span> |
| <span class="source-line-no">029</span><span id="line-29"> * inserted/replaced.</span> |
| <span class="source-line-no">030</span><span id="line-30"> * <p></span> |
| <span class="source-line-no">031</span><span id="line-31"> * Use this when you want to find the largest elements (according to their ordering, not their heap</span> |
| <span class="source-line-no">032</span><span id="line-32"> * size) that consume as close to the specified maxSize as possible. Default behavior is to grow</span> |
| <span class="source-line-no">033</span><span id="line-33"> * just above rather than just below specified max.</span> |
| <span class="source-line-no">034</span><span id="line-34"> * <p></span> |
| <span class="source-line-no">035</span><span id="line-35"> * Object used in this queue must implement {@link HeapSize} as well as {@link Comparable}.</span> |
| <span class="source-line-no">036</span><span id="line-36"> */</span> |
| <span class="source-line-no">037</span><span id="line-37">@InterfaceAudience.Private</span> |
| <span class="source-line-no">038</span><span id="line-38">public class LruCachedBlockQueue implements HeapSize {</span> |
| <span class="source-line-no">039</span><span id="line-39"></span> |
| <span class="source-line-no">040</span><span id="line-40"> private MinMaxPriorityQueue<LruCachedBlock> queue;</span> |
| <span class="source-line-no">041</span><span id="line-41"></span> |
| <span class="source-line-no">042</span><span id="line-42"> private long heapSize;</span> |
| <span class="source-line-no">043</span><span id="line-43"> private long maxSize;</span> |
| <span class="source-line-no">044</span><span id="line-44"></span> |
| <span class="source-line-no">045</span><span id="line-45"> /**</span> |
| <span class="source-line-no">046</span><span id="line-46"> * @param maxSize the target size of elements in the queue</span> |
| <span class="source-line-no">047</span><span id="line-47"> * @param blockSize expected average size of blocks</span> |
| <span class="source-line-no">048</span><span id="line-48"> */</span> |
| <span class="source-line-no">049</span><span id="line-49"> public LruCachedBlockQueue(long maxSize, long blockSize) {</span> |
| <span class="source-line-no">050</span><span id="line-50"> Preconditions.checkArgument(blockSize > 0, "negative blockSize %s", blockSize);</span> |
| <span class="source-line-no">051</span><span id="line-51"> Preconditions.checkArgument(maxSize > 0, "negative maxSize %s", maxSize);</span> |
| <span class="source-line-no">052</span><span id="line-52"> int initialSize = (int) (maxSize / blockSize);</span> |
| <span class="source-line-no">053</span><span id="line-53"> if (initialSize == 0) {</span> |
| <span class="source-line-no">054</span><span id="line-54"> initialSize++;</span> |
| <span class="source-line-no">055</span><span id="line-55"> }</span> |
| <span class="source-line-no">056</span><span id="line-56"> queue = MinMaxPriorityQueue.expectedSize(initialSize).create();</span> |
| <span class="source-line-no">057</span><span id="line-57"> heapSize = 0;</span> |
| <span class="source-line-no">058</span><span id="line-58"> this.maxSize = maxSize;</span> |
| <span class="source-line-no">059</span><span id="line-59"> }</span> |
| <span class="source-line-no">060</span><span id="line-60"></span> |
| <span class="source-line-no">061</span><span id="line-61"> /**</span> |
| <span class="source-line-no">062</span><span id="line-62"> * Attempt to add the specified cached block to this queue.</span> |
| <span class="source-line-no">063</span><span id="line-63"> * <p></span> |
| <span class="source-line-no">064</span><span id="line-64"> * If the queue is smaller than the max size, or if the specified element is ordered before the</span> |
| <span class="source-line-no">065</span><span id="line-65"> * smallest element in the queue, the element will be added to the queue. Otherwise, there is no</span> |
| <span class="source-line-no">066</span><span id="line-66"> * side effect of this call.</span> |
| <span class="source-line-no">067</span><span id="line-67"> * @param cb block to try to add to the queue</span> |
| <span class="source-line-no">068</span><span id="line-68"> */</span> |
| <span class="source-line-no">069</span><span id="line-69"> @edu.umd.cs.findbugs.annotations.SuppressWarnings(</span> |
| <span class="source-line-no">070</span><span id="line-70"> value = "NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE",</span> |
| <span class="source-line-no">071</span><span id="line-71"> justification = "head can not be null as heapSize is greater than maxSize,"</span> |
| <span class="source-line-no">072</span><span id="line-72"> + " which means we have something in the queue")</span> |
| <span class="source-line-no">073</span><span id="line-73"> public void add(LruCachedBlock cb) {</span> |
| <span class="source-line-no">074</span><span id="line-74"> if (heapSize < maxSize) {</span> |
| <span class="source-line-no">075</span><span id="line-75"> queue.add(cb);</span> |
| <span class="source-line-no">076</span><span id="line-76"> heapSize += cb.heapSize();</span> |
| <span class="source-line-no">077</span><span id="line-77"> } else {</span> |
| <span class="source-line-no">078</span><span id="line-78"> LruCachedBlock head = queue.peek();</span> |
| <span class="source-line-no">079</span><span id="line-79"> if (cb.compareTo(head) > 0) {</span> |
| <span class="source-line-no">080</span><span id="line-80"> heapSize += cb.heapSize();</span> |
| <span class="source-line-no">081</span><span id="line-81"> heapSize -= head.heapSize();</span> |
| <span class="source-line-no">082</span><span id="line-82"> if (heapSize > maxSize) {</span> |
| <span class="source-line-no">083</span><span id="line-83"> queue.poll();</span> |
| <span class="source-line-no">084</span><span id="line-84"> } else {</span> |
| <span class="source-line-no">085</span><span id="line-85"> heapSize += head.heapSize();</span> |
| <span class="source-line-no">086</span><span id="line-86"> }</span> |
| <span class="source-line-no">087</span><span id="line-87"> queue.add(cb);</span> |
| <span class="source-line-no">088</span><span id="line-88"> }</span> |
| <span class="source-line-no">089</span><span id="line-89"> }</span> |
| <span class="source-line-no">090</span><span id="line-90"> }</span> |
| <span class="source-line-no">091</span><span id="line-91"></span> |
| <span class="source-line-no">092</span><span id="line-92"> /** Returns The next element in this queue, or {@code null} if the queue is empty. */</span> |
| <span class="source-line-no">093</span><span id="line-93"> public LruCachedBlock poll() {</span> |
| <span class="source-line-no">094</span><span id="line-94"> return queue.poll();</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"> /** Returns The last element in this queue, or {@code null} if the queue is empty. */</span> |
| <span class="source-line-no">098</span><span id="line-98"> public LruCachedBlock pollLast() {</span> |
| <span class="source-line-no">099</span><span id="line-99"> return queue.pollLast();</span> |
| <span class="source-line-no">100</span><span id="line-100"> }</span> |
| <span class="source-line-no">101</span><span id="line-101"></span> |
| <span class="source-line-no">102</span><span id="line-102"> /**</span> |
| <span class="source-line-no">103</span><span id="line-103"> * Total size of all elements in this queue.</span> |
| <span class="source-line-no">104</span><span id="line-104"> * @return size of all elements currently in queue, in bytes</span> |
| <span class="source-line-no">105</span><span id="line-105"> */</span> |
| <span class="source-line-no">106</span><span id="line-106"> @Override</span> |
| <span class="source-line-no">107</span><span id="line-107"> public long heapSize() {</span> |
| <span class="source-line-no">108</span><span id="line-108"> return heapSize;</span> |
| <span class="source-line-no">109</span><span id="line-109"> }</span> |
| <span class="source-line-no">110</span><span id="line-110">}</span> |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| </pre> |
| </div> |
| </main> |
| </body> |
| </html> |
