[SPARK-24196][SQL] Implement Spark's own GetSchemasOperation

sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/operation/GetSchemasOperation.java

@@ -41,7 +41,7 @@ public class GetSchemasOperation extends MetadataOperation {
   .addStringColumn("TABLE_SCHEM", "Schema name.")
   .addStringColumn("TABLE_CATALOG", "Catalog name.");
 
-  private RowSet rowSet;
+  protected RowSet rowSet;
 
   protected GetSchemasOperation(HiveSession parentSession,
       String catalogName, String schemaName) {

sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkGetSchemasOperation.scala

@@ -0,0 +1,66 @@
+/*
+ * 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.hive.thriftserver
+
+import org.apache.hadoop.hive.ql.security.authorization.plugin.HiveOperationType
+import org.apache.hive.service.cli._
+import org.apache.hive.service.cli.operation.GetSchemasOperation
+import org.apache.hive.service.cli.operation.MetadataOperation.DEFAULT_HIVE_CATALOG
+import org.apache.hive.service.cli.session.HiveSession
+
+import org.apache.spark.sql.SQLContext
+
+/**
+ * Spark's own GetSchemasOperation
+ *
+ * @param sqlContext SQLContext to use
+ * @param parentSession a HiveSession from SessionManager
+ * @param catalogName catalog name. null if not applicable.
+ * @param schemaName database name, null or a concrete database name
+ */
+private[hive] class SparkGetSchemasOperation(
+    sqlContext: SQLContext,
+    parentSession: HiveSession,
+    catalogName: String,
+    schemaName: String)
+  extends GetSchemasOperation(parentSession, catalogName, schemaName) {
+
+  override def runInternal(): Unit = {
+    setState(OperationState.RUNNING)
+    // Always use the latest class loader provided by executionHive's state.
+    val executionHiveClassLoader = sqlContext.sharedState.jarClassLoader
+    Thread.currentThread().setContextClassLoader(executionHiveClassLoader)
+
+    if (isAuthV2Enabled) {
+      val cmdStr = s"catalog : $catalogName, schemaPattern : $schemaName"
+      authorizeMetaGets(HiveOperationType.GET_TABLES, null, cmdStr)
+    }
+
+    try {
+      val schemaPattern = convertSchemaPattern(schemaName)
+      sqlContext.sessionState.catalog.listDatabases(schemaPattern).foreach { dbName =>
+        rowSet.addRow(Array[AnyRef](dbName, DEFAULT_HIVE_CATALOG))
+      }
+      setState(OperationState.FINISHED)
+    } catch {
+      case e: HiveSQLException =>
+        setState(OperationState.ERROR)
+        throw e
+    }
+  }
+}

sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/server/SparkSQLOperationManager.scala

@@ -21,13 +21,13 @@ import java.util.{Map => JMap}
 import java.util.concurrent.ConcurrentHashMap
 
 import org.apache.hive.service.cli._
-import org.apache.hive.service.cli.operation.{ExecuteStatementOperation, Operation, OperationManager}
+import org.apache.hive.service.cli.operation.{ExecuteStatementOperation, GetSchemasOperation, Operation, OperationManager}
 import org.apache.hive.service.cli.session.HiveSession
 
 import org.apache.spark.internal.Logging
 import org.apache.spark.sql.SQLContext
 import org.apache.spark.sql.hive.HiveUtils
-import org.apache.spark.sql.hive.thriftserver.{ReflectionUtils, SparkExecuteStatementOperation}
+import org.apache.spark.sql.hive.thriftserver.{ReflectionUtils, SparkExecuteStatementOperation, SparkGetSchemasOperation}
 import org.apache.spark.sql.internal.SQLConf
 
 /**
@@ -63,6 +63,19 @@ private[thriftserver] class SparkSQLOperationManager()
     operation
   }
 
+  override def newGetSchemasOperation(
+      parentSession: HiveSession,
+      catalogName: String,
+      schemaName: String): GetSchemasOperation = synchronized {
+    val sqlContext = sessionToContexts.get(parentSession.getSessionHandle)
+    require(sqlContext != null, s"Session handle: ${parentSession.getSessionHandle} has not been" +
+      " initialized or had already closed.")
+    val operation = new SparkGetSchemasOperation(sqlContext, parentSession, catalogName, schemaName)
+    handleToOperation.put(operation.getHandle, operation)
+    logDebug(s"Created GetSchemasOperation with session=$parentSession.")
+    operation
+  }
+
   def setConfMap(conf: SQLConf, confMap: java.util.Map[String, String]): Unit = {
     val iterator = confMap.entrySet().iterator()
     while (iterator.hasNext) {

sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/HiveThriftServer2Suites.scala

@@ -818,6 +818,22 @@ abstract class HiveThriftJdbcTest extends HiveThriftServer2Test {
     }
   }
 
+  def withDatabase(dbNames: String*)(fs: (Statement => Unit)*) {
+    val user = System.getProperty("user.name")
+    val connections = fs.map { _ => DriverManager.getConnection(jdbcUri, user, "") }
+    val statements = connections.map(_.createStatement())
+
+    try {
+      statements.zip(fs).foreach { case (s, f) => f(s) }
+    } finally {
+      dbNames.foreach { name =>
+        statements(0).execute(s"DROP DATABASE IF EXISTS $name")
+      }
+      statements.foreach(_.close())
+      connections.foreach(_.close())
+    }
+  }
+
   def withJdbcStatement(tableNames: String*)(f: Statement => Unit) {
     withMultipleConnectionJdbcStatement(tableNames: _*)(f)
   }

sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/SparkMetadataOperationSuite.scala

@@ -0,0 +1,103 @@
+/*
+ * 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.hive.thriftserver
+
+import java.util.Properties
+
+import org.apache.hive.jdbc.{HiveConnection, HiveQueryResultSet, Utils => JdbcUtils}
+import org.apache.hive.service.auth.PlainSaslHelper
+import org.apache.hive.service.cli.thrift._
+import org.apache.thrift.protocol.TBinaryProtocol
+import org.apache.thrift.transport.TSocket
+
+class SparkMetadataOperationSuite extends HiveThriftJdbcTest {
+
+  override def mode: ServerMode.Value = ServerMode.binary
+
+  test("Spark's own GetSchemasOperation(SparkGetSchemasOperation)") {
+    def testGetSchemasOperation(
+        catalog: String,
+        schemaPattern: String)(f: HiveQueryResultSet => Unit): Unit = {
+      val rawTransport = new TSocket("localhost", serverPort)
+      val connection = new HiveConnection(s"jdbc:hive2://localhost:$serverPort", new Properties)
+      val user = System.getProperty("user.name")
+      val transport = PlainSaslHelper.getPlainTransport(user, "anonymous", rawTransport)
+      val client = new TCLIService.Client(new TBinaryProtocol(transport))
+      transport.open()
+      var rs: HiveQueryResultSet = null
+      try {
+        val openResp = client.OpenSession(new TOpenSessionReq)
+        val sessHandle = openResp.getSessionHandle
+        val schemaReq = new TGetSchemasReq(sessHandle)
+
+        if (catalog != null) {
+          schemaReq.setCatalogName(catalog)
+        }
+
+        if (schemaPattern == null) {
+          schemaReq.setSchemaName("%")
+        } else {
+          schemaReq.setSchemaName(schemaPattern)
+        }
+
+        val schemaResp = client.GetSchemas(schemaReq)
+        JdbcUtils.verifySuccess(schemaResp.getStatus)
+
+        rs = new HiveQueryResultSet.Builder(connection)
+          .setClient(client)
+          .setSessionHandle(sessHandle)
+          .setStmtHandle(schemaResp.getOperationHandle)
+          .build()
+        f(rs)
+      } finally {
+        rs.close()
+        connection.close()
+        transport.close()
+        rawTransport.close()
+      }
+    }
+
+    def checkResult(dbNames: Seq[String], rs: HiveQueryResultSet): Unit = {
+      if (dbNames.nonEmpty) {
+        for (i <- dbNames.indices) {
+          assert(rs.next())
+          assert(rs.getString("TABLE_SCHEM") === dbNames(i))
+        }
+      } else {
+        assert(!rs.next())
+      }
+    }
+
+    withDatabase("db1", "db2") { statement =>
+      Seq("CREATE DATABASE db1", "CREATE DATABASE db2").foreach(statement.execute)
+
+      testGetSchemasOperation(null, "%") { rs =>
+        checkResult(Seq("db1", "db2"), rs)
+      }
+      testGetSchemasOperation(null, "db1") { rs =>
+        checkResult(Seq("db1"), rs)
+      }
+      testGetSchemasOperation(null, "db_not_exist") { rs =>
+        checkResult(Seq.empty, rs)
+      }
+      testGetSchemasOperation(null, "db*") { rs =>
+        checkResult(Seq("db1", "db2"), rs)
+      }
+    }
+  }
+}