| /** |
| * 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 |
| * <p> |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * <p> |
| * 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.storm.trident.windowing; |
| |
| import java.io.Serializable; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Enumeration; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| /** |
| * Inmemory store implementation of {@code WindowsStore} which can be backed by persistent store. |
| */ |
| public class InMemoryWindowsStore implements WindowsStore, Serializable { |
| |
| private final ConcurrentHashMap<String, Object> store = new ConcurrentHashMap<>(); |
| |
| private int maxSize; |
| private AtomicInteger currentSize; |
| private WindowsStore backingStore; |
| |
| public InMemoryWindowsStore() { |
| } |
| |
| /** |
| * @param maxSize maximum size of inmemory store |
| * @param backingStore backing store containing the entries |
| */ |
| public InMemoryWindowsStore(int maxSize, WindowsStore backingStore) { |
| this.maxSize = maxSize; |
| currentSize = new AtomicInteger(); |
| this.backingStore = backingStore; |
| } |
| |
| @Override |
| public Object get(String key) { |
| Object value = store.get(key); |
| |
| if (value == null && backingStore != null) { |
| value = backingStore.get(key); |
| } |
| |
| return value; |
| } |
| |
| @Override |
| public Iterable<Object> get(List<String> keys) { |
| List<Object> values = new ArrayList<>(); |
| for (String key : keys) { |
| values.add(get(key)); |
| } |
| return values; |
| } |
| |
| @Override |
| public Iterable<String> getAllKeys() { |
| if (backingStore != null) { |
| return backingStore.getAllKeys(); |
| } |
| |
| final Enumeration<String> storeEnumeration = store.keys(); |
| final Iterator<String> resultIterator = new Iterator<String>() { |
| @Override |
| public boolean hasNext() { |
| return storeEnumeration.hasMoreElements(); |
| } |
| |
| @Override |
| public String next() { |
| return storeEnumeration.nextElement(); |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException("remove operation is not supported as it is immutable."); |
| } |
| }; |
| |
| return new Iterable<String>() { |
| @Override |
| public Iterator<String> iterator() { |
| return resultIterator; |
| } |
| }; |
| } |
| |
| @Override |
| public void put(String key, Object value) { |
| _put(key, value); |
| |
| if (backingStore != null) { |
| backingStore.put(key, value); |
| } |
| } |
| |
| private void _put(String key, Object value) { |
| if (!canAdd()) { |
| return; |
| } |
| |
| store.put(key, value); |
| incrementCurrentSize(); |
| } |
| |
| private void incrementCurrentSize() { |
| if (backingStore != null) { |
| currentSize.incrementAndGet(); |
| } |
| } |
| |
| private boolean canAdd() { |
| return backingStore == null || currentSize.get() < maxSize; |
| } |
| |
| @Override |
| public void putAll(Collection<Entry> entries) { |
| for (Entry entry : entries) { |
| _put(entry.key, entry.value); |
| } |
| if (backingStore != null) { |
| backingStore.putAll(entries); |
| } |
| } |
| |
| @Override |
| public void remove(String key) { |
| _remove(key); |
| |
| if (backingStore != null) { |
| backingStore.remove(key); |
| } |
| } |
| |
| private void _remove(String key) { |
| Object oldValue = store.remove(key); |
| |
| if (oldValue != null) { |
| decrementSize(); |
| if (backingStore != null) { |
| backingStore.remove(key); |
| } |
| } |
| |
| } |
| |
| private void decrementSize() { |
| if (backingStore != null) { |
| currentSize.decrementAndGet(); |
| } |
| } |
| |
| @Override |
| public void removeAll(Collection<String> keys) { |
| for (String key : keys) { |
| _remove(key); |
| } |
| |
| if (backingStore != null) { |
| backingStore.removeAll(keys); |
| } |
| } |
| |
| @Override |
| public void shutdown() { |
| store.clear(); |
| |
| if (backingStore != null) { |
| backingStore.shutdown(); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return "InMemoryWindowsStore{" + |
| " store:size = " + store.size() + |
| " backingStore = " + backingStore + |
| '}'; |
| } |
| } |