| /** |
| * 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.apex.malhar.lib.appdata.schemas; |
| |
| import java.io.Serializable; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.apache.apex.malhar.lib.appdata.datastructs.DimensionalTable; |
| |
| import com.google.common.base.Preconditions; |
| |
| /** |
| * This class is a schema registry which can hold multiple schemas. It is intended to be |
| * used in operators that serve multiple schemas. |
| * @since 3.0.0 |
| */ |
| public class SchemaRegistryMultiple implements SchemaRegistry, Serializable |
| { |
| private static final long serialVersionUID = 201505121108L; |
| |
| /** |
| * The dimensional table which holds the mapping from schema keys to schemas. |
| */ |
| private DimensionalTable<Schema> table; |
| private Comparator<Schema> schemaComparator; |
| |
| /** |
| * Constructor for serialization. |
| */ |
| private SchemaRegistryMultiple() |
| { |
| //for Kryo |
| } |
| |
| /** |
| * The names of all the schema keys for all schemas in this registry. |
| * @param schemaKeys The names of all the schema keys for all schemas in this registry. |
| */ |
| public SchemaRegistryMultiple(List<String> schemaKeys) |
| { |
| table = new DimensionalTable<Schema>(schemaKeys); |
| } |
| |
| /** |
| * The names of all the schema keys for all schemas in this registry. |
| * @param schemaKeys The names of all the schema keys for all schemas in this registry. |
| * @param schemaComparator The comparator used to order the schemas returned in the {@link SchemaResult} produced |
| * by {@link SchemaRegistryMultiple#getSchemaResult(org.apache.apex.malhar.lib.appdata.schemas.SchemaQuery)} |
| */ |
| public SchemaRegistryMultiple(List<String> schemaKeys, Comparator<Schema> schemaComparator) |
| { |
| this(schemaKeys); |
| this.schemaComparator = Preconditions.checkNotNull(schemaComparator); |
| } |
| |
| @Override |
| public SchemaResult getSchemaResult(SchemaQuery schemaQuery) |
| { |
| Map<String, String> schemaKeys = schemaQuery.getSchemaKeys(); |
| List<Schema> data = null; |
| |
| if (schemaKeys == null) { |
| data = table.getAllDataPoints(); |
| } else { |
| data = table.getDataPoints(schemaKeys); |
| } |
| |
| if (schemaComparator != null) { |
| Collections.sort(data, schemaComparator); |
| } |
| |
| if (data.isEmpty()) { |
| return null; |
| } |
| |
| return new SchemaResult(schemaQuery, data); |
| } |
| |
| @Override |
| public void registerSchema(Schema schema) |
| { |
| Map<String, String> schemaKeys = schema.getSchemaKeys(); |
| table.appendRow(schema, schemaKeys); |
| } |
| |
| @Override |
| public Schema getSchema(Map<String, String> schemaKeys) |
| { |
| return table.getDataPoint(schemaKeys); |
| } |
| |
| @Override |
| public void registerSchema(Schema schema, Map<String, String> schemaKeys) |
| { |
| schema.setSchemaKeys(schemaKeys); |
| table.appendRow(schema, schemaKeys); |
| } |
| |
| @Override |
| public int size() |
| { |
| return table.size(); |
| } |
| } |