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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.util;</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.Collection;</span> | 
 | <span class="source-line-no">023</span><span id="line-23">import java.util.HashMap;</span> | 
 | <span class="source-line-no">024</span><span id="line-24">import java.util.List;</span> | 
 | <span class="source-line-no">025</span><span id="line-25">import java.util.Locale;</span> | 
 | <span class="source-line-no">026</span><span id="line-26">import java.util.Map;</span> | 
 | <span class="source-line-no">027</span><span id="line-27">import java.util.Objects;</span> | 
 | <span class="source-line-no">028</span><span id="line-28">import org.apache.yetus.audience.InterfaceAudience;</span> | 
 | <span class="source-line-no">029</span><span id="line-29"></span> | 
 | <span class="source-line-no">030</span><span id="line-30">/**</span> | 
 | <span class="source-line-no">031</span><span id="line-31"> * The <code>PoolMap</code> maps a key to a collection of values, the elements of which are managed</span> | 
 | <span class="source-line-no">032</span><span id="line-32"> * by a pool. In effect, that collection acts as a shared pool of resources, access to which is</span> | 
 | <span class="source-line-no">033</span><span id="line-33"> * closely controlled as per the semantics of the pool.</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"> * In case the size of the pool is set to a non-zero positive number, that is used to cap the number</span> | 
 | <span class="source-line-no">036</span><span id="line-36"> * of resources that a pool may contain for any given key. A size of {@link Integer#MAX_VALUE} is</span> | 
 | <span class="source-line-no">037</span><span id="line-37"> * interpreted as an unbounded pool.</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"> * <p></span> | 
 | <span class="source-line-no">040</span><span id="line-40"> * PoolMap is thread-safe. It does not remove elements automatically. Unused resources must be</span> | 
 | <span class="source-line-no">041</span><span id="line-41"> * closed and removed explicitly.</span> | 
 | <span class="source-line-no">042</span><span id="line-42"> * </p></span> | 
 | <span class="source-line-no">043</span><span id="line-43"> * @param <K> the type of the key to the resource</span> | 
 | <span class="source-line-no">044</span><span id="line-44"> * @param <V> the type of the resource being pooled</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 PoolMap<K, V> {</span> | 
 | <span class="source-line-no">048</span><span id="line-48">  private final Map<K, Pool<V>> pools;</span> | 
 | <span class="source-line-no">049</span><span id="line-49">  private final PoolType poolType;</span> | 
 | <span class="source-line-no">050</span><span id="line-50">  private final int poolMaxSize;</span> | 
 | <span class="source-line-no">051</span><span id="line-51"></span> | 
 | <span class="source-line-no">052</span><span id="line-52">  public PoolMap(PoolType poolType, int poolMaxSize) {</span> | 
 | <span class="source-line-no">053</span><span id="line-53">    pools = new HashMap<>();</span> | 
 | <span class="source-line-no">054</span><span id="line-54">    this.poolType = poolType;</span> | 
 | <span class="source-line-no">055</span><span id="line-55">    this.poolMaxSize = poolMaxSize;</span> | 
 | <span class="source-line-no">056</span><span id="line-56">  }</span> | 
 | <span class="source-line-no">057</span><span id="line-57"></span> | 
 | <span class="source-line-no">058</span><span id="line-58">  public V getOrCreate(K key, PoolResourceSupplier<V> supplier) throws IOException {</span> | 
 | <span class="source-line-no">059</span><span id="line-59">    synchronized (pools) {</span> | 
 | <span class="source-line-no">060</span><span id="line-60">      Pool<V> pool = pools.get(key);</span> | 
 | <span class="source-line-no">061</span><span id="line-61"></span> | 
 | <span class="source-line-no">062</span><span id="line-62">      if (pool == null) {</span> | 
 | <span class="source-line-no">063</span><span id="line-63">        pool = createPool();</span> | 
 | <span class="source-line-no">064</span><span id="line-64">        pools.put(key, pool);</span> | 
 | <span class="source-line-no">065</span><span id="line-65">      }</span> | 
 | <span class="source-line-no">066</span><span id="line-66"></span> | 
 | <span class="source-line-no">067</span><span id="line-67">      try {</span> | 
 | <span class="source-line-no">068</span><span id="line-68">        return pool.getOrCreate(supplier);</span> | 
 | <span class="source-line-no">069</span><span id="line-69">      } catch (IOException | RuntimeException | Error e) {</span> | 
 | <span class="source-line-no">070</span><span id="line-70">        if (pool.size() == 0) {</span> | 
 | <span class="source-line-no">071</span><span id="line-71">          pools.remove(key);</span> | 
 | <span class="source-line-no">072</span><span id="line-72">        }</span> | 
 | <span class="source-line-no">073</span><span id="line-73"></span> | 
 | <span class="source-line-no">074</span><span id="line-74">        throw e;</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"></span> | 
 | <span class="source-line-no">079</span><span id="line-79">  public boolean remove(K key, V value) {</span> | 
 | <span class="source-line-no">080</span><span id="line-80">    synchronized (pools) {</span> | 
 | <span class="source-line-no">081</span><span id="line-81">      Pool<V> pool = pools.get(key);</span> | 
 | <span class="source-line-no">082</span><span id="line-82"></span> | 
 | <span class="source-line-no">083</span><span id="line-83">      if (pool == null) {</span> | 
 | <span class="source-line-no">084</span><span id="line-84">        return false;</span> | 
 | <span class="source-line-no">085</span><span id="line-85">      }</span> | 
 | <span class="source-line-no">086</span><span id="line-86"></span> | 
 | <span class="source-line-no">087</span><span id="line-87">      boolean removed = pool.remove(value);</span> | 
 | <span class="source-line-no">088</span><span id="line-88"></span> | 
 | <span class="source-line-no">089</span><span id="line-89">      if (removed && pool.size() == 0) {</span> | 
 | <span class="source-line-no">090</span><span id="line-90">        pools.remove(key);</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">      return removed;</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">  public List<V> values() {</span> | 
 | <span class="source-line-no">098</span><span id="line-98">    List<V> values = new ArrayList<>();</span> | 
 | <span class="source-line-no">099</span><span id="line-99"></span> | 
 | <span class="source-line-no">100</span><span id="line-100">    synchronized (pools) {</span> | 
 | <span class="source-line-no">101</span><span id="line-101">      for (Pool<V> pool : pools.values()) {</span> | 
 | <span class="source-line-no">102</span><span id="line-102">        Collection<V> poolValues = pool.values();</span> | 
 | <span class="source-line-no">103</span><span id="line-103">        if (poolValues != null) {</span> | 
 | <span class="source-line-no">104</span><span id="line-104">          values.addAll(poolValues);</span> | 
 | <span class="source-line-no">105</span><span id="line-105">        }</span> | 
 | <span class="source-line-no">106</span><span id="line-106">      }</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">    return values;</span> | 
 | <span class="source-line-no">110</span><span id="line-110">  }</span> | 
 | <span class="source-line-no">111</span><span id="line-111"></span> | 
 | <span class="source-line-no">112</span><span id="line-112">  public void clear() {</span> | 
 | <span class="source-line-no">113</span><span id="line-113">    synchronized (pools) {</span> | 
 | <span class="source-line-no">114</span><span id="line-114">      for (Pool<V> pool : pools.values()) {</span> | 
 | <span class="source-line-no">115</span><span id="line-115">        pool.clear();</span> | 
 | <span class="source-line-no">116</span><span id="line-116">      }</span> | 
 | <span class="source-line-no">117</span><span id="line-117"></span> | 
 | <span class="source-line-no">118</span><span id="line-118">      pools.clear();</span> | 
 | <span class="source-line-no">119</span><span id="line-119">    }</span> | 
 | <span class="source-line-no">120</span><span id="line-120">  }</span> | 
 | <span class="source-line-no">121</span><span id="line-121"></span> | 
 | <span class="source-line-no">122</span><span id="line-122">  public interface PoolResourceSupplier<R> {</span> | 
 | <span class="source-line-no">123</span><span id="line-123">    R get() throws IOException;</span> | 
 | <span class="source-line-no">124</span><span id="line-124">  }</span> | 
 | <span class="source-line-no">125</span><span id="line-125"></span> | 
 | <span class="source-line-no">126</span><span id="line-126">  protected static <V> V createResource(PoolResourceSupplier<V> supplier) throws IOException {</span> | 
 | <span class="source-line-no">127</span><span id="line-127">    V resource = supplier.get();</span> | 
 | <span class="source-line-no">128</span><span id="line-128">    return Objects.requireNonNull(resource, "resource cannot be null.");</span> | 
 | <span class="source-line-no">129</span><span id="line-129">  }</span> | 
 | <span class="source-line-no">130</span><span id="line-130"></span> | 
 | <span class="source-line-no">131</span><span id="line-131">  protected interface Pool<R> {</span> | 
 | <span class="source-line-no">132</span><span id="line-132">    R getOrCreate(PoolResourceSupplier<R> supplier) throws IOException;</span> | 
 | <span class="source-line-no">133</span><span id="line-133"></span> | 
 | <span class="source-line-no">134</span><span id="line-134">    boolean remove(R resource);</span> | 
 | <span class="source-line-no">135</span><span id="line-135"></span> | 
 | <span class="source-line-no">136</span><span id="line-136">    void clear();</span> | 
 | <span class="source-line-no">137</span><span id="line-137"></span> | 
 | <span class="source-line-no">138</span><span id="line-138">    Collection<R> values();</span> | 
 | <span class="source-line-no">139</span><span id="line-139"></span> | 
 | <span class="source-line-no">140</span><span id="line-140">    int size();</span> | 
 | <span class="source-line-no">141</span><span id="line-141">  }</span> | 
 | <span class="source-line-no">142</span><span id="line-142"></span> | 
 | <span class="source-line-no">143</span><span id="line-143">  public enum PoolType {</span> | 
 | <span class="source-line-no">144</span><span id="line-144">    ThreadLocal,</span> | 
 | <span class="source-line-no">145</span><span id="line-145">    RoundRobin;</span> | 
 | <span class="source-line-no">146</span><span id="line-146"></span> | 
 | <span class="source-line-no">147</span><span id="line-147">    public static PoolType valueOf(String poolTypeName, PoolType defaultPoolType) {</span> | 
 | <span class="source-line-no">148</span><span id="line-148">      PoolType poolType = PoolType.fuzzyMatch(poolTypeName);</span> | 
 | <span class="source-line-no">149</span><span id="line-149">      return (poolType != null) ? poolType : defaultPoolType;</span> | 
 | <span class="source-line-no">150</span><span id="line-150">    }</span> | 
 | <span class="source-line-no">151</span><span id="line-151"></span> | 
 | <span class="source-line-no">152</span><span id="line-152">    public static String fuzzyNormalize(String name) {</span> | 
 | <span class="source-line-no">153</span><span id="line-153">      return name != null ? name.replaceAll("-", "").trim().toLowerCase(Locale.ROOT) : "";</span> | 
 | <span class="source-line-no">154</span><span id="line-154">    }</span> | 
 | <span class="source-line-no">155</span><span id="line-155"></span> | 
 | <span class="source-line-no">156</span><span id="line-156">    public static PoolType fuzzyMatch(String name) {</span> | 
 | <span class="source-line-no">157</span><span id="line-157">      for (PoolType poolType : values()) {</span> | 
 | <span class="source-line-no">158</span><span id="line-158">        if (fuzzyNormalize(name).equals(fuzzyNormalize(poolType.name()))) {</span> | 
 | <span class="source-line-no">159</span><span id="line-159">          return poolType;</span> | 
 | <span class="source-line-no">160</span><span id="line-160">        }</span> | 
 | <span class="source-line-no">161</span><span id="line-161">      }</span> | 
 | <span class="source-line-no">162</span><span id="line-162">      return null;</span> | 
 | <span class="source-line-no">163</span><span id="line-163">    }</span> | 
 | <span class="source-line-no">164</span><span id="line-164">  }</span> | 
 | <span class="source-line-no">165</span><span id="line-165"></span> | 
 | <span class="source-line-no">166</span><span id="line-166">  protected Pool<V> createPool() {</span> | 
 | <span class="source-line-no">167</span><span id="line-167">    switch (poolType) {</span> | 
 | <span class="source-line-no">168</span><span id="line-168">      case RoundRobin:</span> | 
 | <span class="source-line-no">169</span><span id="line-169">        return new RoundRobinPool<>(poolMaxSize);</span> | 
 | <span class="source-line-no">170</span><span id="line-170">      case ThreadLocal:</span> | 
 | <span class="source-line-no">171</span><span id="line-171">        return new ThreadLocalPool<>();</span> | 
 | <span class="source-line-no">172</span><span id="line-172">      default:</span> | 
 | <span class="source-line-no">173</span><span id="line-173">        return new RoundRobinPool<>(poolMaxSize);</span> | 
 | <span class="source-line-no">174</span><span id="line-174">    }</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">  /**</span> | 
 | <span class="source-line-no">178</span><span id="line-178">   * The <code>RoundRobinPool</code> represents a {@link PoolMap.Pool}, which stores its resources</span> | 
 | <span class="source-line-no">179</span><span id="line-179">   * in an {@link ArrayList}. It load-balances access to its resources by returning a different</span> | 
 | <span class="source-line-no">180</span><span id="line-180">   * resource every time a given key is looked up.</span> | 
 | <span class="source-line-no">181</span><span id="line-181">   * <p></span> | 
 | <span class="source-line-no">182</span><span id="line-182">   * If {@link #maxSize} is set to {@link Integer#MAX_VALUE}, then the size of the pool is</span> | 
 | <span class="source-line-no">183</span><span id="line-183">   * unbounded. Otherwise, it caps the number of resources in this pool to the (non-zero positive)</span> | 
 | <span class="source-line-no">184</span><span id="line-184">   * value specified in {@link #maxSize}.</span> | 
 | <span class="source-line-no">185</span><span id="line-185">   * </p></span> | 
 | <span class="source-line-no">186</span><span id="line-186">   * @param <R> the type of the resource</span> | 
 | <span class="source-line-no">187</span><span id="line-187">   */</span> | 
 | <span class="source-line-no">188</span><span id="line-188">  @SuppressWarnings("serial")</span> | 
 | <span class="source-line-no">189</span><span id="line-189">  static class RoundRobinPool<R> implements Pool<R> {</span> | 
 | <span class="source-line-no">190</span><span id="line-190">    private final List<R> resources;</span> | 
 | <span class="source-line-no">191</span><span id="line-191">    private final int maxSize;</span> | 
 | <span class="source-line-no">192</span><span id="line-192"></span> | 
 | <span class="source-line-no">193</span><span id="line-193">    private int nextIndex;</span> | 
 | <span class="source-line-no">194</span><span id="line-194"></span> | 
 | <span class="source-line-no">195</span><span id="line-195">    public RoundRobinPool(int maxSize) {</span> | 
 | <span class="source-line-no">196</span><span id="line-196">      if (maxSize <= 0) {</span> | 
 | <span class="source-line-no">197</span><span id="line-197">        throw new IllegalArgumentException("maxSize must be positive");</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">      resources = new ArrayList<>(maxSize);</span> | 
 | <span class="source-line-no">201</span><span id="line-201">      this.maxSize = maxSize;</span> | 
 | <span class="source-line-no">202</span><span id="line-202">    }</span> | 
 | <span class="source-line-no">203</span><span id="line-203"></span> | 
 | <span class="source-line-no">204</span><span id="line-204">    @Override</span> | 
 | <span class="source-line-no">205</span><span id="line-205">    public R getOrCreate(PoolResourceSupplier<R> supplier) throws IOException {</span> | 
 | <span class="source-line-no">206</span><span id="line-206">      int size = resources.size();</span> | 
 | <span class="source-line-no">207</span><span id="line-207">      R resource;</span> | 
 | <span class="source-line-no">208</span><span id="line-208"></span> | 
 | <span class="source-line-no">209</span><span id="line-209">      /* letting pool to grow */</span> | 
 | <span class="source-line-no">210</span><span id="line-210">      if (size < maxSize) {</span> | 
 | <span class="source-line-no">211</span><span id="line-211">        resource = createResource(supplier);</span> | 
 | <span class="source-line-no">212</span><span id="line-212">        resources.add(resource);</span> | 
 | <span class="source-line-no">213</span><span id="line-213">      } else {</span> | 
 | <span class="source-line-no">214</span><span id="line-214">        resource = resources.get(nextIndex);</span> | 
 | <span class="source-line-no">215</span><span id="line-215"></span> | 
 | <span class="source-line-no">216</span><span id="line-216">        /* at this point size cannot be 0 */</span> | 
 | <span class="source-line-no">217</span><span id="line-217">        nextIndex = (nextIndex + 1) % size;</span> | 
 | <span class="source-line-no">218</span><span id="line-218">      }</span> | 
 | <span class="source-line-no">219</span><span id="line-219"></span> | 
 | <span class="source-line-no">220</span><span id="line-220">      return resource;</span> | 
 | <span class="source-line-no">221</span><span id="line-221">    }</span> | 
 | <span class="source-line-no">222</span><span id="line-222"></span> | 
 | <span class="source-line-no">223</span><span id="line-223">    @Override</span> | 
 | <span class="source-line-no">224</span><span id="line-224">    public boolean remove(R resource) {</span> | 
 | <span class="source-line-no">225</span><span id="line-225">      return resources.remove(resource);</span> | 
 | <span class="source-line-no">226</span><span id="line-226">    }</span> | 
 | <span class="source-line-no">227</span><span id="line-227"></span> | 
 | <span class="source-line-no">228</span><span id="line-228">    @Override</span> | 
 | <span class="source-line-no">229</span><span id="line-229">    public void clear() {</span> | 
 | <span class="source-line-no">230</span><span id="line-230">      resources.clear();</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">    @Override</span> | 
 | <span class="source-line-no">234</span><span id="line-234">    public Collection<R> values() {</span> | 
 | <span class="source-line-no">235</span><span id="line-235">      return resources;</span> | 
 | <span class="source-line-no">236</span><span id="line-236">    }</span> | 
 | <span class="source-line-no">237</span><span id="line-237"></span> | 
 | <span class="source-line-no">238</span><span id="line-238">    @Override</span> | 
 | <span class="source-line-no">239</span><span id="line-239">    public int size() {</span> | 
 | <span class="source-line-no">240</span><span id="line-240">      return resources.size();</span> | 
 | <span class="source-line-no">241</span><span id="line-241">    }</span> | 
 | <span class="source-line-no">242</span><span id="line-242">  }</span> | 
 | <span class="source-line-no">243</span><span id="line-243"></span> | 
 | <span class="source-line-no">244</span><span id="line-244">  /**</span> | 
 | <span class="source-line-no">245</span><span id="line-245">   * The <code>ThreadLocalPool</code> represents a {@link PoolMap.Pool} that works similarly to</span> | 
 | <span class="source-line-no">246</span><span id="line-246">   * {@link ThreadLocal} class. It essentially binds the resource to the thread from which it is</span> | 
 | <span class="source-line-no">247</span><span id="line-247">   * accessed. It doesn't remove resources when a thread exits, those resources must be closed</span> | 
 | <span class="source-line-no">248</span><span id="line-248">   * manually.</span> | 
 | <span class="source-line-no">249</span><span id="line-249">   * <p></span> | 
 | <span class="source-line-no">250</span><span id="line-250">   * Note that the size of the pool is essentially bounded by the number of threads that add</span> | 
 | <span class="source-line-no">251</span><span id="line-251">   * resources to this pool.</span> | 
 | <span class="source-line-no">252</span><span id="line-252">   * </p></span> | 
 | <span class="source-line-no">253</span><span id="line-253">   * @param <R> the type of the resource</span> | 
 | <span class="source-line-no">254</span><span id="line-254">   */</span> | 
 | <span class="source-line-no">255</span><span id="line-255">  static class ThreadLocalPool<R> implements Pool<R> {</span> | 
 | <span class="source-line-no">256</span><span id="line-256">    private final Map<Thread, R> resources;</span> | 
 | <span class="source-line-no">257</span><span id="line-257"></span> | 
 | <span class="source-line-no">258</span><span id="line-258">    public ThreadLocalPool() {</span> | 
 | <span class="source-line-no">259</span><span id="line-259">      resources = new HashMap<>();</span> | 
 | <span class="source-line-no">260</span><span id="line-260">    }</span> | 
 | <span class="source-line-no">261</span><span id="line-261"></span> | 
 | <span class="source-line-no">262</span><span id="line-262">    @Override</span> | 
 | <span class="source-line-no">263</span><span id="line-263">    public R getOrCreate(PoolResourceSupplier<R> supplier) throws IOException {</span> | 
 | <span class="source-line-no">264</span><span id="line-264">      Thread myself = Thread.currentThread();</span> | 
 | <span class="source-line-no">265</span><span id="line-265">      R resource = resources.get(myself);</span> | 
 | <span class="source-line-no">266</span><span id="line-266"></span> | 
 | <span class="source-line-no">267</span><span id="line-267">      if (resource == null) {</span> | 
 | <span class="source-line-no">268</span><span id="line-268">        resource = createResource(supplier);</span> | 
 | <span class="source-line-no">269</span><span id="line-269">        resources.put(myself, resource);</span> | 
 | <span class="source-line-no">270</span><span id="line-270">      }</span> | 
 | <span class="source-line-no">271</span><span id="line-271"></span> | 
 | <span class="source-line-no">272</span><span id="line-272">      return resource;</span> | 
 | <span class="source-line-no">273</span><span id="line-273">    }</span> | 
 | <span class="source-line-no">274</span><span id="line-274"></span> | 
 | <span class="source-line-no">275</span><span id="line-275">    @Override</span> | 
 | <span class="source-line-no">276</span><span id="line-276">    public boolean remove(R resource) {</span> | 
 | <span class="source-line-no">277</span><span id="line-277">      /* remove can be called from any thread */</span> | 
 | <span class="source-line-no">278</span><span id="line-278">      return resources.values().remove(resource);</span> | 
 | <span class="source-line-no">279</span><span id="line-279">    }</span> | 
 | <span class="source-line-no">280</span><span id="line-280"></span> | 
 | <span class="source-line-no">281</span><span id="line-281">    @Override</span> | 
 | <span class="source-line-no">282</span><span id="line-282">    public int size() {</span> | 
 | <span class="source-line-no">283</span><span id="line-283">      return resources.size();</span> | 
 | <span class="source-line-no">284</span><span id="line-284">    }</span> | 
 | <span class="source-line-no">285</span><span id="line-285"></span> | 
 | <span class="source-line-no">286</span><span id="line-286">    @Override</span> | 
 | <span class="source-line-no">287</span><span id="line-287">    public void clear() {</span> | 
 | <span class="source-line-no">288</span><span id="line-288">      resources.clear();</span> | 
 | <span class="source-line-no">289</span><span id="line-289">    }</span> | 
 | <span class="source-line-no">290</span><span id="line-290"></span> | 
 | <span class="source-line-no">291</span><span id="line-291">    @Override</span> | 
 | <span class="source-line-no">292</span><span id="line-292">    public Collection<R> values() {</span> | 
 | <span class="source-line-no">293</span><span id="line-293">      return resources.values();</span> | 
 | <span class="source-line-no">294</span><span id="line-294">    }</span> | 
 | <span class="source-line-no">295</span><span id="line-295">  }</span> | 
 | <span class="source-line-no">296</span><span id="line-296">}</span> | 
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 | </pre> | 
 | </div> | 
 | </main> | 
 | </body> | 
 | </html> |