| /* |
| * 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.hugegraph.backend.store; |
| |
| import org.apache.hugegraph.exception.ConnectionException; |
| import org.apache.hugegraph.type.HugeType; |
| |
| public abstract class AbstractBackendStore<Session extends BackendSession> |
| implements BackendStore { |
| |
| // TODO: move SystemSchemaStore into backend like MetaStore |
| private final SystemSchemaStore systemSchemaStore; |
| private final MetaDispatcher<Session> dispatcher; |
| |
| public AbstractBackendStore() { |
| this.systemSchemaStore = new SystemSchemaStore(); |
| this.dispatcher = new MetaDispatcher<>(); |
| } |
| |
| protected MetaDispatcher<Session> metaDispatcher() { |
| return this.dispatcher; |
| } |
| |
| public void registerMetaHandler(String name, MetaHandler<Session> handler) { |
| this.dispatcher.registerMetaHandler(name, handler); |
| } |
| |
| @Override |
| public String storedVersion() { |
| throw new UnsupportedOperationException( |
| "AbstractBackendStore.storedVersion()"); |
| } |
| |
| @Override |
| public SystemSchemaStore systemSchemaStore() { |
| return this.systemSchemaStore; |
| } |
| |
| // Get metadata by key |
| @Override |
| public <R> R metadata(HugeType type, String meta, Object[] args) { |
| Session session = this.session(type); |
| MetaDispatcher<Session> dispatcher; |
| if (type == null) { |
| dispatcher = this.metaDispatcher(); |
| } else { |
| BackendTable<Session, ?> table = this.table(type); |
| dispatcher = table.metaDispatcher(); |
| } |
| return dispatcher.dispatchMetaHandler(session, meta, args); |
| } |
| |
| protected void checkOpened() throws ConnectionException { |
| if (!this.opened()) { |
| throw new ConnectionException( |
| "The '%s' store of %s has not been opened", |
| this.database(), this.provider().type()); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return String.format("%s/%s", this.database(), this.store()); |
| } |
| |
| protected abstract BackendTable<Session, ?> table(HugeType type); |
| |
| // NOTE: Need to support passing null |
| protected abstract Session session(HugeType type); |
| } |