| /** |
| * 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 com.datatorrent.lib.appdata.schemas; |
| |
| import java.util.Map; |
| |
| /** |
| * This interface describes a SchemaRegistry. A schema registry is used to store and look up |
| * schemas for App Data enabled operators which serve data from multiple schemas. {@link SchemaRegistry}s |
| * are primarily used to create responses to {@link SchemaQuery}s. |
| * @since 3.0.0 |
| */ |
| public interface SchemaRegistry |
| { |
| /** |
| * This produces the schema result for a given schema query. |
| * @param schemaQuery The schema query to produce a result for. |
| * @return The schema result. |
| */ |
| public SchemaResult getSchemaResult(SchemaQuery schemaQuery); |
| |
| /** |
| * Registers the given schema with this schema registry. |
| * @param schema The schema to register with this registry. |
| */ |
| public void registerSchema(Schema schema); |
| |
| /** |
| * Registers the given schema with the given schema keys. |
| * @param schema The schema to register. |
| * @param schemaKeys The schema keys that correspond with the given schema. |
| */ |
| public void registerSchema(Schema schema, Map<String, String> schemaKeys); |
| |
| /** |
| * Gets the schema corresponding to the given schema keys. |
| * @param schemaKeys The schema keys for a schema. |
| * @return The schema corresponding to the given schema keys. Null if no schema was found |
| * for the given schema keys. |
| */ |
| public Schema getSchema(Map<String, String> schemaKeys); |
| |
| /** |
| * Gets the number of schemas in the schema registry. |
| * @return The number of schemas in the schema registry. |
| */ |
| public int size(); |
| } |