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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.shardingsphere.single.route.engine;
19  
20  import lombok.AccessLevel;
21  import lombok.NoArgsConstructor;
22  import org.apache.shardingsphere.infra.metadata.database.schema.QualifiedTable;
23  import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
24  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.AlterSchemaStatement;
25  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.CreateSchemaStatement;
26  import org.apache.shardingsphere.sql.parser.sql.common.statement.ddl.DropSchemaStatement;
27  
28  import java.util.Collection;
29  import java.util.Optional;
30  
31  /**
32   * Single route engine factory.
33   */
34  @NoArgsConstructor(access = AccessLevel.PRIVATE)
35  public final class SingleRouteEngineFactory {
36      
37      /**
38       * Create new instance of single route engine.
39       *
40       * @param singleTables single tables
41       * @param sqlStatement SQL statement
42       * @return created instance
43       */
44      public static Optional<SingleRouteEngine> newInstance(final Collection<QualifiedTable> singleTables, final SQLStatement sqlStatement) {
45          if (!singleTables.isEmpty()) {
46              return Optional.of(new SingleStandardRouteEngine(singleTables, sqlStatement));
47          }
48          // TODO move this logic to common route logic
49          if (isSchemaDDLStatement(sqlStatement)) {
50              return Optional.of(new SingleDatabaseBroadcastRouteEngine());
51          }
52          return Optional.empty();
53      }
54      
55      private static boolean isSchemaDDLStatement(final SQLStatement sqlStatement) {
56          return sqlStatement instanceof CreateSchemaStatement || sqlStatement instanceof AlterSchemaStatement || sqlStatement instanceof DropSchemaStatement;
57      }
58  }