| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.trevni; |
| |
| import java.util.Random; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.nio.ByteBuffer; |
| |
| import org.junit.Assert; |
| import org.junit.Test; |
| |
| public class TestUtil { |
| |
| private static long seed; |
| private static boolean seedSet; |
| |
| /** Returns the random seed for this test run. By default uses the current |
| * time, but a test run can be replicated by specifying the "test.seed" |
| * system property. The seed is printed the first time it's accessed so that |
| * failures can be replicated if needed. */ |
| public static long getRandomSeed() { |
| if (!seedSet) { |
| String configured = System.getProperty("test.seed"); |
| if (configured != null) |
| seed = Long.valueOf(configured); |
| else |
| seed = System.currentTimeMillis(); |
| System.err.println("test.seed="+seed); |
| seedSet = true; |
| } |
| return seed; |
| } |
| |
| public static void resetRandomSeed() { |
| seedSet = false; |
| } |
| |
| public static Random createRandom() { |
| return new Random(getRandomSeed()); |
| } |
| |
| public static ByteBuffer randomBytes(Random random) { |
| byte[] bytes = new byte[randomLength(random)]; |
| random.nextBytes(bytes); |
| return ByteBuffer.wrap(bytes); |
| } |
| |
| public static String randomString(Random random) { |
| int length = randomLength(random); |
| char[] chars = new char[length]; |
| for (int i = 0; i < length; i++) |
| chars[i] = (char)('a'+random.nextInt('z'-'a')); |
| return new String(chars); |
| } |
| |
| /** Returns [0-15] 15/16 times. |
| * Returns [0-255] 255/256 times. |
| * Returns [0-4095] 4095/4096 times. |
| * Returns [0-65535] every time. */ |
| public static int randomLength(Random random) { |
| int n = random.nextInt(); |
| if (n < 0) n = -n; |
| return n & |
| ((n & 0xF0000) != 0 |
| ? 0xF |
| : ((n & 0xFF0000) != 0 |
| ? 0xFF |
| : ((n & 0xFFF0000) != 0 |
| ? 0xFFF |
| : 0xFFFF))); |
| } |
| |
| @Test public void testRandomLength() { |
| long total = 0; |
| int count = 1024 * 1024; |
| int min = Short.MAX_VALUE; |
| int max = 0; |
| Random r = createRandom(); |
| for (int i = 0; i < count; i++) { |
| int length = randomLength(r); |
| if (min > length) min = length; |
| if (max < length) max = length; |
| total += length; |
| } |
| Assert.assertEquals(0, min); |
| Assert.assertTrue(max > 1024 * 32); |
| |
| float average = total / (float)count; |
| Assert.assertTrue(average > 16.0f); |
| Assert.assertTrue(average < 64.0f); |
| |
| } |
| |
| } |