/**
* Copyright 2013 Cloudera Inc.
*
* Licensed 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.kitesdk.data.hbase.impl;
import java.util.Collection;
import java.util.List;
import java.util.Map;
/**
* Interface for managing schemas with a meta store. This interface provides
* various methods for accessing the schema values in the meta store, as well as
* methods for creating or migrating new schemas.
*/
public interface SchemaManager {
/**
* Returns true if this entity manager knows of a managed schema in the
* specified table that goes by the entityName.
*
* @param tableName
* The table name of the managed schema.
* @param entityName
* The entity name of the managed schema.
* @return True if it has it, false otherwise
*/
public boolean hasManagedSchema(String tableName, String entityName);
/**
* Get the key schema for managed schema.
*
* @param tableName
* The table name of the managed schema.
* @param entityName
* The entity name of the managed schema.
* @return The key schema.
* @throws org.kitesdk.data.SchemaNotFoundException
*/
public KeySchema getKeySchema(String tableName, String entityName);
/**
* Get the entity schema for the managed schema. This will return the entity
* schema with the greatest version.
*
* @param tableName
* The table name of the managed schema.
* @param entityName
* The entity name of the managed schema.
* @return The entity schema
* @throws org.kitesdk.data.SchemaNotFoundException
*/
public EntitySchema getEntitySchema(String tableName, String entityName);
/**
* Get a specified version of the entity schema for the managed schema.
*
* @param tableName
* The table name of the managed schema.
* @param entityName
* The entity name of the managed schema.
* @param version
* The version of the entity schema.
* @return The entity schema
* @throws org.kitesdk.data.SchemaNotFoundException
*/
public EntitySchema getEntitySchema(String tableName, String entityName,
int version);
/**
* Get all entity schema versions for a managed schema identified by the table
* name and entity name.
*
* @param tableName
* The table name of the managed schema
* @param entityName
* The entity name of the managed schema
* @return The map of versioned entity schemas.
*/
public Map<Integer, EntitySchema> getEntitySchemas(String tableName,
String entityName);
/**
* Function takes an entity schema, and the table name and entity name of a
* managed schema, and will return the version of that entity schema.
*
* @param tableName
* The table name of the managed schema.
* @param entityName
* The entity name of the managed schema.
* @param schema
* The entity schema, whose version this method will return.
* @return The entity schema's version
* @throws org.kitesdk.data.SchemaNotFoundException
*/
public int getEntityVersion(String tableName, String entityName,
EntitySchema schema);
/**
* Checks whether the given {@link EntitySchema} is already managed as a
* version for the given {@code tableName} and {@code entityName}.
*
* This checks the current schema manager state and does not refresh the
* cached schemas.
*
* @param tableName
* The table name of the managed schema.
* @param entityName
* The entity name of the managed schema.
* @param version
* The entity schema that may already be managed.
* @return {@code true} if the given {@code EntitySchema} is a known version,
* {@code false} otherwise
* @see #refreshManagedSchemaCache(String, String)
*/
public boolean hasSchemaVersion(String tableName, String entityName,
EntitySchema version);
/**
* Refresh the underlying ManagedSchema cache for a specific table name,
* entity name pair. This will ensure that calls to get key or entity schemas
* will return the latest data in the meta store.
*
* @param tableName
* The table name of the managed schema.
* @param entityName
* The entity name of the managed schema.
*/
public void refreshManagedSchemaCache(String tableName, String entityName);
/**
* Creates a new schema version. There must be no previous schema for this
* table/entity name pair.
*
* @param tableName
* The table name of the managed schema
* @param entityName
* The entity name of the managed schema
* @param keySchema
* The schema of the key being added
* @param entitySchema
* The schema of the entity being added
* @throws org.kitesdk.data.IncompatibleSchemaException
* if a previous schema exists
* @throws org.kitesdk.data.ConcurrentSchemaModificationException
* @throws org.kitesdk.data.ValidationException
*/
public void createSchema(String tableName, String entityName,
String entitySchemaStr, String schemaType,
String keySerDeType, String entitySerDeType);
/**
* Creates a new schema version. The new schema must be an allowed schema
* upgrade, which is dictated by the implementation.
*
* @param tableName
* The table name of the managed schema
* @param entityName
* The entity name of the managed schema
* @param newSchema
* The new schema
* @throws org.kitesdk.data.SchemaNotFoundException
* @throws org.kitesdk.data.IncompatibleSchemaException
* @throws org.kitesdk.data.ConcurrentSchemaModificationException
* @throws org.kitesdk.data.ValidationException
*/
public void migrateSchema(String tableName, String entityName,
String newSchema);
public void deleteSchema(String tableName, String entityName);
/**
* Returns the entity names for a table. If no such table exists then an empty list
* will be returned.
* @param tableName
* The table name of the managed schema
* @return The entity names for the table.
*/
public List<String> getEntityNames(String tableName);
/**
* Returns the known tables with managed schemas. If no such tables exist,
* then an empty list will be returned.
* @return The table names with managed schemas.
*/
public Collection<String> getTableNames();
}