001/*
002 * (C) Copyright 2017 Nuxeo (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Florent Guillaume
018 */
019package org.nuxeo.ecm.core.storage.kv;
020
021import java.util.Map;
022import java.util.concurrent.ConcurrentHashMap;
023
024import org.apache.commons.logging.Log;
025import org.apache.commons.logging.LogFactory;
026import org.nuxeo.ecm.core.api.NuxeoException;
027import org.nuxeo.runtime.model.ComponentInstance;
028import org.nuxeo.runtime.model.DefaultComponent;
029
030/**
031 * Implementation for the Key/Value Service.
032 *
033 * @since 9.1
034 */
035public class KeyValueServiceImpl extends DefaultComponent implements KeyValueService {
036
037    private static final Log log = LogFactory.getLog(KeyValueServiceImpl.class);
038
039    public static final String CONFIG_XP = "configuration";
040
041    public static final String DEFAULT_STORE_ID = "default";
042
043    protected final KeyValueStoreRegistry registry = new KeyValueStoreRegistry();
044
045    protected Map<String, KeyValueStoreProvider> providers = new ConcurrentHashMap<>();
046
047    protected KeyValueStore defaultStore = new MemKeyValueStore();
048
049    @Override
050    public void registerContribution(Object contribution, String extensionPoint, ComponentInstance contributor) {
051        switch (extensionPoint) {
052        case CONFIG_XP:
053            registerKeyValueStore((KeyValueStoreDescriptor) contribution);
054            break;
055        default:
056            throw new NuxeoException("Unknown extension point: " + extensionPoint);
057        }
058    }
059
060    @Override
061    public void unregisterContribution(Object contribution, String extensionPoint, ComponentInstance contributor) {
062        switch (extensionPoint) {
063        case CONFIG_XP:
064            unregisterKeyValueStore((KeyValueStoreDescriptor) contribution);
065            break;
066        }
067    }
068
069    public void registerKeyValueStore(KeyValueStoreDescriptor descriptor) {
070        registry.addContribution(descriptor);
071        descriptorChanged(descriptor.name);
072        log.info("Registered key/value store: " + descriptor.name);
073    }
074
075    public void unregisterKeyValueStore(KeyValueStoreDescriptor descriptor) {
076        registry.removeContribution(descriptor);
077        descriptorChanged(descriptor.name);
078        log.info("Unregistered key/value store: " + descriptor.name);
079    }
080
081    // ===== KeyValueService =====
082
083    @Override
084    public synchronized KeyValueStore getKeyValueStore(String name) {
085        KeyValueStoreProvider provider = providers.get(name);
086        if (provider == null) {
087            KeyValueStoreDescriptor descriptor = registry.getKeyValueStoreDescriptor(name);
088            if (descriptor == null) {
089                descriptor = registry.getKeyValueStoreDescriptor(DEFAULT_STORE_ID);
090                if (descriptor == null) {
091                    return defaultStore;
092                }
093            }
094            try {
095                provider = descriptor.getKlass().newInstance();
096                provider.initialize(descriptor.getProperties());
097            } catch (ReflectiveOperationException e) {
098                throw new NuxeoException(e);
099            }
100            providers.put(name, provider);
101        }
102        return provider;
103    }
104
105    /* Close previous provider if we're overwriting it. */
106    protected synchronized void descriptorChanged(String name) {
107        KeyValueStoreProvider provider = providers.remove(name);
108        if (provider != null) {
109            provider.close();
110        }
111    }
112
113}