Merge changes Ia47e566b,Ib94d79a9 am: d8eae0de70 am: 53eee16439

am: b91bd88c5e

Change-Id: Ied2b31c9d1219b8aebf5fec085ab598b77bede6e

tests/net/java/com/android/internal/util/RingBufferTest.java

@@ -0,0 +1,145 @@
+/*
+ * 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");
+            }
+        }
+    }
+}