[SPARK-13078][SQL] API and test cases for internal catalog

This pull request creates an internal catalog API. The creation of this API is the first step towards consolidating SQLContext and HiveContext. I envision we will have two different implementations in Spark 2.0: (1) a simple in-memory implementation, and (2) an implementation based on the current HiveClient (ClientWrapper).

I took a look at what Hive's internal metastore interface/implementation, and then created this API based on it. I believe this is the minimal set needed in order to achieve all the needed functionality.

Author: Reynold Xin <[email protected]>

Closes #10982 from rxin/SPARK-13078.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/InMemoryCatalog.scala

@@ -0,0 +1,246 @@
+/*
+ * 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.catalyst.catalog
+
+import scala.collection.mutable
+
+import org.apache.spark.sql.AnalysisException
+
+
+/**
+ * An in-memory (ephemeral) implementation of the system catalog.
+ *
+ * All public methods should be synchronized for thread-safety.
+ */
+class InMemoryCatalog extends Catalog {
+
+  private class TableDesc(var table: Table) {
+    val partitions = new mutable.HashMap[String, TablePartition]
+  }
+
+  private class DatabaseDesc(var db: Database) {
+    val tables = new mutable.HashMap[String, TableDesc]
+    val functions = new mutable.HashMap[String, Function]
+  }
+
+  private val catalog = new scala.collection.mutable.HashMap[String, DatabaseDesc]
+
+  private def filterPattern(names: Seq[String], pattern: String): Seq[String] = {
+    val regex = pattern.replaceAll("\\*", ".*").r
+    names.filter { funcName => regex.pattern.matcher(funcName).matches() }
+  }
+
+  private def existsFunction(db: String, funcName: String): Boolean = {
+    catalog(db).functions.contains(funcName)
+  }
+
+  private def existsTable(db: String, table: String): Boolean = {
+    catalog(db).tables.contains(table)
+  }
+
+  private def assertDbExists(db: String): Unit = {
+    if (!catalog.contains(db)) {
+      throw new AnalysisException(s"Database $db does not exist")
+    }
+  }
+
+  private def assertFunctionExists(db: String, funcName: String): Unit = {
+    assertDbExists(db)
+    if (!existsFunction(db, funcName)) {
+      throw new AnalysisException(s"Function $funcName does not exists in $db database")
+    }
+  }
+
+  private def assertTableExists(db: String, table: String): Unit = {
+    assertDbExists(db)
+    if (!existsTable(db, table)) {
+      throw new AnalysisException(s"Table $table does not exists in $db database")
+    }
+  }
+
+  // --------------------------------------------------------------------------
+  // Databases
+  // --------------------------------------------------------------------------
+
+  override def createDatabase(dbDefinition: Database, ifNotExists: Boolean): Unit = synchronized {
+    if (catalog.contains(dbDefinition.name)) {
+      if (!ifNotExists) {
+        throw new AnalysisException(s"Database ${dbDefinition.name} already exists.")
+      }
+    } else {
+      catalog.put(dbDefinition.name, new DatabaseDesc(dbDefinition))
+    }
+  }
+
+  override def dropDatabase(
+    db: String,
+    ignoreIfNotExists: Boolean,
+    cascade: Boolean): Unit = synchronized {
+    if (catalog.contains(db)) {
+      if (!cascade) {
+        // If cascade is false, make sure the database is empty.
+        if (catalog(db).tables.nonEmpty) {
+          throw new AnalysisException(s"Database $db is not empty. One or more tables exist.")
+        }
+        if (catalog(db).functions.nonEmpty) {
+          throw new AnalysisException(s"Database $db is not empty. One or more functions exist.")
+        }
+      }
+      // Remove the database.
+      catalog.remove(db)
+    } else {
+      if (!ignoreIfNotExists) {
+        throw new AnalysisException(s"Database $db does not exist")
+      }
+    }
+  }
+
+  override def alterDatabase(db: String, dbDefinition: Database): Unit = synchronized {
+    assertDbExists(db)
+    assert(db == dbDefinition.name)
+    catalog(db).db = dbDefinition
+  }
+
+  override def getDatabase(db: String): Database = synchronized {
+    assertDbExists(db)
+    catalog(db).db
+  }
+
+  override def listDatabases(): Seq[String] = synchronized {
+    catalog.keySet.toSeq
+  }
+
+  override def listDatabases(pattern: String): Seq[String] = synchronized {
+    filterPattern(listDatabases(), pattern)
+  }
+
+  // --------------------------------------------------------------------------
+  // Tables
+  // --------------------------------------------------------------------------
+
+  override def createTable(db: String, tableDefinition: Table, ifNotExists: Boolean)
+  : Unit = synchronized {
+    assertDbExists(db)
+    if (existsTable(db, tableDefinition.name)) {
+      if (!ifNotExists) {
+        throw new AnalysisException(s"Table ${tableDefinition.name} already exists in $db database")
+      }
+    } else {
+      catalog(db).tables.put(tableDefinition.name, new TableDesc(tableDefinition))
+    }
+  }
+
+  override def dropTable(db: String, table: String, ignoreIfNotExists: Boolean)
+  : Unit = synchronized {
+    assertDbExists(db)
+    if (existsTable(db, table)) {
+      catalog(db).tables.remove(table)
+    } else {
+      if (!ignoreIfNotExists) {
+        throw new AnalysisException(s"Table $table does not exist in $db database")
+      }
+    }
+  }
+
+  override def renameTable(db: String, oldName: String, newName: String): Unit = synchronized {
+    assertTableExists(db, oldName)
+    val oldDesc = catalog(db).tables(oldName)
+    oldDesc.table = oldDesc.table.copy(name = newName)
+    catalog(db).tables.put(newName, oldDesc)
+    catalog(db).tables.remove(oldName)
+  }
+
+  override def alterTable(db: String, table: String, tableDefinition: Table): Unit = synchronized {
+    assertTableExists(db, table)
+    assert(table == tableDefinition.name)
+    catalog(db).tables(table).table = tableDefinition
+  }
+
+  override def getTable(db: String, table: String): Table = synchronized {
+    assertTableExists(db, table)
+    catalog(db).tables(table).table
+  }
+
+  override def listTables(db: String): Seq[String] = synchronized {
+    assertDbExists(db)
+    catalog(db).tables.keySet.toSeq
+  }
+
+  override def listTables(db: String, pattern: String): Seq[String] = synchronized {
+    assertDbExists(db)
+    filterPattern(listTables(db), pattern)
+  }
+
+  // --------------------------------------------------------------------------
+  // Partitions
+  // --------------------------------------------------------------------------
+
+  override def alterPartition(db: String, table: String, part: TablePartition)
+  : Unit = synchronized {
+    throw new UnsupportedOperationException
+  }
+
+  override def alterPartitions(db: String, table: String, parts: Seq[TablePartition])
+  : Unit = synchronized {
+    throw new UnsupportedOperationException
+  }
+
+  // --------------------------------------------------------------------------
+  // Functions
+  // --------------------------------------------------------------------------
+
+  override def createFunction(
+      db: String, func: Function, ifNotExists: Boolean): Unit = synchronized {
+    assertDbExists(db)
+
+    if (existsFunction(db, func.name)) {
+      if (!ifNotExists) {
+        throw new AnalysisException(s"Function $func already exists in $db database")
+      }
+    } else {
+      catalog(db).functions.put(func.name, func)
+    }
+  }
+
+  override def dropFunction(db: String, funcName: String): Unit = synchronized {
+    assertFunctionExists(db, funcName)
+    catalog(db).functions.remove(funcName)
+  }
+
+  override def alterFunction(db: String, funcName: String, funcDefinition: Function)
+    : Unit = synchronized {
+    assertFunctionExists(db, funcName)
+    if (funcName != funcDefinition.name) {
+      // Also a rename; remove the old one and add the new one back
+      catalog(db).functions.remove(funcName)
+    }
+    catalog(db).functions.put(funcName, funcDefinition)
+  }
+
+  override def getFunction(db: String, funcName: String): Function = synchronized {
+    assertFunctionExists(db, funcName)
+    catalog(db).functions(funcName)
+  }
+
+  override def listFunctions(db: String, pattern: String): Seq[String] = synchronized {
+    assertDbExists(db)
+    val regex = pattern.replaceAll("\\*", ".*").r
+    filterPattern(catalog(db).functions.keysIterator.toSeq, pattern)
+  }
+
+}