Java tutorial
/* * 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.jackrabbit.oak.plugins.document.persistentCache; import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertFalse; import static org.junit.Assert.assertTrue; import java.io.ByteArrayInputStream; import java.io.File; import java.io.FileOutputStream; import java.util.Random; import com.google.common.cache.Cache; import org.apache.commons.io.FileUtils; import org.apache.jackrabbit.oak.cache.CacheLIRS; import org.apache.jackrabbit.oak.plugins.document.PathRev; import org.apache.jackrabbit.oak.plugins.document.Revision; import org.apache.jackrabbit.oak.plugins.document.RevisionVector; import org.apache.jackrabbit.oak.plugins.document.util.StringValue; import org.apache.jackrabbit.oak.spi.blob.BlobStore; import org.apache.jackrabbit.oak.spi.blob.MemoryBlobStore; import org.junit.Test; public class CacheTest { @Test public void recoverIfCorrupt() throws Exception { FileUtils.deleteDirectory(new File("target/cacheTest")); new File("target/cacheTest").mkdirs(); FileOutputStream out = new FileOutputStream("target/cacheTest/cache-0.data"); out.write("corrupt".getBytes()); out.close(); PersistentCache pCache = new PersistentCache("target/cacheTest"); CacheLIRS<PathRev, StringValue> cache = new CacheLIRS.Builder<PathRev, StringValue>().maximumSize(1) .build(); Cache<PathRev, StringValue> map = pCache.wrap(null, null, cache, CacheType.DIFF); String largeString = new String(new char[1024 * 1024]); for (int counter = 0; counter < 10; counter++) { long end = System.currentTimeMillis() + 100; while (System.currentTimeMillis() < end) { Thread.yield(); } for (int i = 0; i < 100; i++) { PathRev k = new PathRev("/" + counter, new RevisionVector(new Revision(0, 0, i))); map.getIfPresent(k); map.put(k, new StringValue(largeString)); } } assertTrue("Exceptions: " + pCache.getExceptionCount(), pCache.getExceptionCount() < 100); } @Test public void closeAlways() throws Exception { FileUtils.deleteDirectory(new File("target/cacheTest")); PersistentCache cache = new PersistentCache("target/cacheTest,manualCommit"); CacheMap<String, String> map = cache.openMap(0, "test", null); // break the map by calling interrupt Thread.currentThread().interrupt(); map.put("hello", "world"); cache.close(); assertFalse(Thread.interrupted()); } @Test public void deleteOldAtStartup() throws Exception { FileUtils.deleteDirectory(new File("target/cacheTest")); new File("target/cacheTest").mkdirs(); new File("target/cacheTest/cache-0.data").createNewFile(); new File("target/cacheTest/cache-1.data").createNewFile(); new File("target/cacheTest/cache-2.data").createNewFile(); new File("target/cacheTest/cache-3.data").createNewFile(); PersistentCache cache = new PersistentCache("target/cacheTest"); cache.close(); assertFalse(new File("target/cacheTest/cache-0.data").exists()); assertFalse(new File("target/cacheTest/cache-1.data").exists()); assertTrue(new File("target/cacheTest/cache-2.data").exists()); assertTrue(new File("target/cacheTest/cache-3.data").exists()); } @Test public void test() throws Exception { FileUtils.deleteDirectory(new File("target/cacheTest")); PersistentCache cache = new PersistentCache("target/cacheTest,size=1,-compress"); try { MemoryBlobStore mem = new MemoryBlobStore(); mem.setBlockSizeMin(100); BlobStore b = cache.wrapBlobStore(mem); Random r = new Random(); for (int i = 0; i < 10000; i++) { byte[] data = new byte[100]; r.nextBytes(data); String id = b.writeBlob(new ByteArrayInputStream(data)); b.readBlob(id, 0, new byte[1], 0, 1); } } finally { cache.close(); } } @Test public void interrupt() throws Exception { FileUtils.deleteDirectory(new File("target/cacheTest")); PersistentCache cache = new PersistentCache("target/cacheTest,size=1,-compress"); try { CacheMap<String, String> m1 = cache.openMap(0, "m1", null); CacheMap<String, String> m2 = cache.openMap(0, "test", null); // the cache file was opened once so far assertEquals(1, cache.getOpenCount()); // we store 20 mb of data, to ensure not all data is kept in memory String largeString = new String(new char[1024 * 1024]); int count = 10; for (int i = 0; i < count; i++) { m1.put("x" + i, largeString); m2.put("y" + i, largeString); } // interrupt the thread, which will cause the FileChannel // to be closed in the next read operation Thread.currentThread().interrupt(); // this will force at least one read operation, // which should re-open the maps for (int i = 0; i < count; i++) { m1.get("x" + i); m2.get("y" + i); } assertEquals(2, cache.getOpenCount()); // re-opening will clear the interrupt flag assertFalse(Thread.interrupted()); } finally { cache.close(); } } }