1 /*
   2  * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package jdk.incubator.http.internal.hpack;
  24 
  25 import org.testng.annotations.BeforeClass;
  26 import org.testng.annotations.Test;
  27 import jdk.incubator.http.internal.hpack.HeaderTable.CircularBuffer;
  28 
  29 import java.util.Queue;
  30 import java.util.Random;
  31 import java.util.concurrent.ArrayBlockingQueue;
  32 
  33 import static org.testng.Assert.assertEquals;
  34 import static jdk.incubator.http.internal.hpack.TestHelper.newRandom;
  35 
  36 public final class CircularBufferTest {
  37 
  38     private final Random r = newRandom();
  39 
  40     @BeforeClass
  41     public void setUp() {
  42         r.setSeed(System.currentTimeMillis());
  43     }
  44 
  45     @Test
  46     public void queue() {
  47         for (int capacity = 1; capacity <= 2048; capacity++) {
  48             queueOnce(capacity, 32);
  49         }
  50     }
  51 
  52     @Test
  53     public void resize() {
  54         for (int capacity = 1; capacity <= 4096; capacity++) {
  55             resizeOnce(capacity);
  56         }
  57     }
  58 
  59     @Test
  60     public void downSizeEmptyBuffer() {
  61         CircularBuffer<Integer> buffer = new CircularBuffer<>(16);
  62         buffer.resize(15);
  63     }
  64 
  65     private void resizeOnce(int capacity) {
  66 
  67         int nextNumberToPut = 0;
  68 
  69         Queue<Integer> referenceQueue = new ArrayBlockingQueue<>(capacity);
  70         CircularBuffer<Integer> buffer = new CircularBuffer<>(capacity);
  71 
  72         // Fill full, so the next add will wrap
  73         for (int i = 0; i < capacity; i++, nextNumberToPut++) {
  74             buffer.add(nextNumberToPut);
  75             referenceQueue.add(nextNumberToPut);
  76         }
  77         int gets = r.nextInt(capacity); // [0, capacity)
  78         for (int i = 0; i < gets; i++) {
  79             referenceQueue.poll();
  80             buffer.remove();
  81         }
  82         int puts = r.nextInt(gets + 1); // [0, gets]
  83         for (int i = 0; i < puts; i++, nextNumberToPut++) {
  84             buffer.add(nextNumberToPut);
  85             referenceQueue.add(nextNumberToPut);
  86         }
  87 
  88         Integer[] expected = referenceQueue.toArray(new Integer[0]);
  89         buffer.resize(expected.length);
  90 
  91         assertEquals(buffer.elements, expected);
  92     }
  93 
  94     private void queueOnce(int capacity, int numWraps) {
  95 
  96         Queue<Integer> referenceQueue = new ArrayBlockingQueue<>(capacity);
  97         CircularBuffer<Integer> buffer = new CircularBuffer<>(capacity);
  98 
  99         int nextNumberToPut = 0;
 100         int totalPuts = 0;
 101         int putsLimit = capacity * numWraps;
 102         int remainingCapacity = capacity;
 103         int size = 0;
 104 
 105         while (totalPuts < putsLimit) {
 106             assert remainingCapacity + size == capacity;
 107             int puts = r.nextInt(remainingCapacity + 1); // [0, remainingCapacity]
 108             remainingCapacity -= puts;
 109             size += puts;
 110             for (int i = 0; i < puts; i++, nextNumberToPut++) {
 111                 referenceQueue.add(nextNumberToPut);
 112                 buffer.add(nextNumberToPut);
 113             }
 114             totalPuts += puts;
 115             int gets = r.nextInt(size + 1); // [0, size]
 116             size -= gets;
 117             remainingCapacity += gets;
 118             for (int i = 0; i < gets; i++) {
 119                 Integer expected = referenceQueue.poll();
 120                 Integer actual = buffer.remove();
 121                 assertEquals(actual, expected);
 122             }
 123         }
 124     }
 125 }