brkyvz commented on a change in pull request #25368: [SPARK-28635][SQL] create CatalogManager to track registered v2 catalogs URL: https://github.com/apache/spark/pull/25368#discussion_r313696942
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalog/v2/CatalogManager.scala ########## @@ -0,0 +1,100 @@ +/* + * 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.spark.sql.catalog.v2 + +import scala.collection.mutable +import scala.util.control.NonFatal + +import org.apache.spark.internal.Logging +import org.apache.spark.sql.internal.SQLConf + +/** + * A thread-safe manager for [[CatalogPlugin]]s. It tracks all the registered catalogs, and allow + * the caller to look up a catalog by name. + */ +class CatalogManager(conf: SQLConf) extends Logging { + + private val catalogs = mutable.HashMap.empty[String, CatalogPlugin] + + def catalog(name: String): CatalogPlugin = synchronized { + catalogs.getOrElseUpdate(name, Catalogs.load(name, conf)) + } + + def defaultCatalog: Option[CatalogPlugin] = { + conf.defaultV2Catalog.flatMap { catalogName => + try { + Some(catalog(catalogName)) + } catch { + case NonFatal(e) => + logError(s"Cannot load default v2 catalog: $catalogName", e) + None + } + } + } + + def v2SessionCatalog: Option[CatalogPlugin] = { + try { + Some(catalog(CatalogManager.SESSION_CATALOG_NAME)) + } catch { + case NonFatal(e) => + logError("Cannot load v2 session catalog", e) + None + } + } + + private def getDefaultNamespace(c: CatalogPlugin) = c match { + case c: SupportsNamespaces => c.defaultNamespace() + case _ => Array.empty[String] + } + + private var _currentNamespace = { + // The builtin catalog use "default" as the default database. Review comment: I'm thinking more about whether this should be the duty of the CatalogManager or the catalog itself... My thoughts are: 1. Once the V2SessionCatalog `SupportsNamespaces`, it can have the default namespace `default` set within it 2. When you run a command like `USE foo.bar` where `foo` is the catalog, we should set the default namespace within that catalog to be `bar`. 3. What if the `default` catalog doesn't support namespaces in the first place? I'm a bit worried that having the default namespace setting in the CatalogManager can lead to a split brain situation. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
