| /* |
| * 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.drill.exec.planner.sql; |
| |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentMap; |
| |
| import org.apache.drill.shaded.guava.com.google.common.collect.Maps; |
| |
| /** |
| * A special type of concurrent map which attempts to create an object before returning that it does not exist. It will also provide the same functionality on it's keyset. |
| * @param <KEY> The key in the map. |
| * @param <VALUE> The value in the map. |
| */ |
| public class ExpandingConcurrentMap<KEY, VALUE> implements ConcurrentMap<KEY, VALUE> { |
| static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(ExpandingConcurrentMap.class); |
| |
| private final ConcurrentMap<KEY, VALUE> internalMap = Maps.newConcurrentMap(); |
| private final DelegatingKeySet keySet = new DelegatingKeySet(); |
| private final MapValueFactory<KEY, VALUE> fac; |
| |
| /** |
| * Create a new ExpandingConcurrentMap. |
| * @param fac The object factory responsible for attempting to generate object instances. |
| */ |
| public ExpandingConcurrentMap(MapValueFactory<KEY, VALUE> fac) { |
| super(); |
| this.fac = fac; |
| } |
| |
| @Override |
| public int size() { |
| return internalMap.size(); |
| } |
| |
| @Override |
| public boolean isEmpty() { |
| return internalMap.isEmpty(); |
| } |
| |
| public boolean alreadyContainsKey(Object k) { |
| @SuppressWarnings("unchecked") KEY key = (KEY) k; |
| |
| if (internalMap.containsKey(key)) { |
| return true; |
| } |
| return false; |
| } |
| |
| @Override |
| public boolean containsKey(Object k) { |
| @SuppressWarnings("unchecked") KEY key = (KEY) k; |
| |
| if (internalMap.containsKey(key)) { |
| return true; |
| } |
| VALUE v = getNewEntry(k); |
| return v != null; |
| } |
| |
| @Override |
| public boolean containsValue(Object value) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public VALUE get(Object key) { |
| VALUE out = internalMap.get(key); |
| if (out != null) { |
| return out; |
| } |
| return getNewEntry(key); |
| } |
| |
| private VALUE getNewEntry(Object k) { |
| @SuppressWarnings("unchecked") |
| KEY key = (KEY) k; |
| VALUE v = this.fac.create(key); |
| if (v == null) { |
| return null; |
| } |
| VALUE old = internalMap.putIfAbsent(key, v); |
| if (old == null) { |
| return v; |
| } |
| fac.destroy(v); |
| return old; |
| } |
| |
| @Override |
| public VALUE put(KEY key, VALUE value) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public VALUE remove(Object key) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public void putAll(Map<? extends KEY, ? extends VALUE> m) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public void clear() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public Set<KEY> keySet() { |
| return this.keySet; |
| } |
| |
| @Override |
| public Collection<VALUE> values() { |
| return internalMap.values(); |
| } |
| |
| @Override |
| public Set<java.util.Map.Entry<KEY, VALUE>> entrySet() { |
| return internalMap.entrySet(); |
| } |
| |
| @Override |
| public VALUE putIfAbsent(KEY key, VALUE value) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean remove(Object key, Object value) { |
| return false; |
| } |
| |
| @Override |
| public boolean replace(KEY key, VALUE oldValue, VALUE newValue) { |
| return false; |
| } |
| |
| @Override |
| public VALUE replace(KEY key, VALUE value) { |
| return null; |
| } |
| |
| private class DelegatingKeySet implements Set<KEY>{ |
| |
| @Override |
| public int size() { |
| return ExpandingConcurrentMap.this.size(); |
| } |
| |
| @Override |
| public boolean isEmpty() { |
| return ExpandingConcurrentMap.this.isEmpty(); |
| } |
| |
| @Override |
| public boolean contains(Object o) { |
| return ExpandingConcurrentMap.this.containsKey(o); |
| } |
| |
| @Override |
| public Iterator<KEY> iterator() { |
| return internalMap.keySet().iterator(); |
| } |
| |
| @Override |
| public Object[] toArray() { |
| return internalMap.keySet().toArray(); |
| } |
| |
| @Override |
| public <T> T[] toArray(T[] a) { |
| return internalMap.keySet().toArray(a); |
| } |
| |
| @Override |
| public boolean add(KEY e) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean remove(Object o) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean containsAll(Collection<?> c) { |
| for (Object o : c) { |
| if (this.contains(o)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| @Override |
| public boolean addAll(Collection<? extends KEY> c) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean retainAll(Collection<?> c) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean removeAll(Collection<?> c) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public void clear() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| } |
| |
| public interface MapValueFactory<KEY, VALUE> { |
| |
| public VALUE create(KEY key); |
| public void destroy(VALUE value); |
| } |
| |
| } |