| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.internal.util; |
| |
| import static org.junit.Assert.assertEquals; |
| import static org.junit.Assert.fail; |
| |
| import android.support.test.filters.SmallTest; |
| import android.support.test.runner.AndroidJUnit4; |
| |
| import org.junit.Test; |
| import org.junit.runner.RunWith; |
| import java.util.Arrays; |
| import java.util.Objects; |
| |
| |
| @SmallTest |
| @RunWith(AndroidJUnit4.class) |
| public class RingBufferTest { |
| |
| @Test |
| public void testEmptyRingBuffer() { |
| RingBuffer<String> buffer = new RingBuffer<>(String.class, 100); |
| |
| assertArraysEqual(new String[0], buffer.toArray()); |
| } |
| |
| @Test |
| public void testIncorrectConstructorArguments() { |
| try { |
| RingBuffer<String> buffer = new RingBuffer<>(String.class, -10); |
| fail("Should not be able to create a negative capacity RingBuffer"); |
| } catch (IllegalArgumentException expected) { |
| } |
| |
| try { |
| RingBuffer<String> buffer = new RingBuffer<>(String.class, 0); |
| fail("Should not be able to create a 0 capacity RingBuffer"); |
| } catch (IllegalArgumentException expected) { |
| } |
| } |
| |
| @Test |
| public void testRingBufferWithNoWrapping() { |
| RingBuffer<String> buffer = new RingBuffer<>(String.class, 100); |
| |
| buffer.append("a"); |
| buffer.append("b"); |
| buffer.append("c"); |
| buffer.append("d"); |
| buffer.append("e"); |
| |
| String[] expected = {"a", "b", "c", "d", "e"}; |
| assertArraysEqual(expected, buffer.toArray()); |
| } |
| |
| @Test |
| public void testRingBufferWithCapacity1() { |
| RingBuffer<String> buffer = new RingBuffer<>(String.class, 1); |
| |
| buffer.append("a"); |
| assertArraysEqual(new String[]{"a"}, buffer.toArray()); |
| |
| buffer.append("b"); |
| assertArraysEqual(new String[]{"b"}, buffer.toArray()); |
| |
| buffer.append("c"); |
| assertArraysEqual(new String[]{"c"}, buffer.toArray()); |
| |
| buffer.append("d"); |
| assertArraysEqual(new String[]{"d"}, buffer.toArray()); |
| |
| buffer.append("e"); |
| assertArraysEqual(new String[]{"e"}, buffer.toArray()); |
| } |
| |
| @Test |
| public void testRingBufferWithWrapping() { |
| int capacity = 100; |
| RingBuffer<String> buffer = new RingBuffer<>(String.class, capacity); |
| |
| buffer.append("a"); |
| buffer.append("b"); |
| buffer.append("c"); |
| buffer.append("d"); |
| buffer.append("e"); |
| |
| String[] expected1 = {"a", "b", "c", "d", "e"}; |
| assertArraysEqual(expected1, buffer.toArray()); |
| |
| String[] expected2 = new String[capacity]; |
| int firstIndex = 0; |
| int lastIndex = capacity - 1; |
| |
| expected2[firstIndex] = "e"; |
| for (int i = 1; i < capacity; i++) { |
| buffer.append("x"); |
| expected2[i] = "x"; |
| } |
| assertArraysEqual(expected2, buffer.toArray()); |
| |
| buffer.append("x"); |
| expected2[firstIndex] = "x"; |
| assertArraysEqual(expected2, buffer.toArray()); |
| |
| for (int i = 0; i < 10; i++) { |
| for (String s : expected2) { |
| buffer.append(s); |
| } |
| } |
| assertArraysEqual(expected2, buffer.toArray()); |
| |
| buffer.append("a"); |
| expected2[lastIndex] = "a"; |
| assertArraysEqual(expected2, buffer.toArray()); |
| } |
| |
| static <T> void assertArraysEqual(T[] expected, T[] got) { |
| if (expected.length != got.length) { |
| fail(Arrays.toString(expected) + " and " + Arrays.toString(got) |
| + " did not have the same length"); |
| } |
| |
| for (int i = 0; i < expected.length; i++) { |
| if (!Objects.equals(expected[i], got[i])) { |
| fail(Arrays.toString(expected) + " and " + Arrays.toString(got) |
| + " were not equal"); |
| } |
| } |
| } |
| } |