org.apache.spark.sql.catalyst.catalog.GlobalTempViewManager.scala Maven / Gradle / Ivy
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/*
* 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 javax.annotation.concurrent.GuardedBy
import scala.collection.mutable
import org.apache.spark.sql.AnalysisException
import org.apache.spark.sql.catalyst.analysis.TempTableAlreadyExistsException
import org.apache.spark.sql.catalyst.plans.logical.LogicalPlan
import org.apache.spark.sql.catalyst.util.StringUtils
/**
* A thread-safe manager for global temporary views, providing atomic operations to manage them,
* e.g. create, update, remove, etc.
*
* Note that, the view name is always case-sensitive here, callers are responsible to format the
* view name w.r.t. case-sensitive config.
*
* @param database The system preserved virtual database that keeps all the global temporary views.
*/
class GlobalTempViewManager(val database: String) {
/** List of view definitions, mapping from view name to logical plan. */
@GuardedBy("this")
private val viewDefinitions = new mutable.HashMap[String, LogicalPlan]
/**
* Returns the global view definition which matches the given name, or None if not found.
*/
def get(name: String): Option[LogicalPlan] = synchronized {
viewDefinitions.get(name)
}
/**
* Creates a global temp view, or issue an exception if the view already exists and
* `overrideIfExists` is false.
*/
def create(
name: String,
viewDefinition: LogicalPlan,
overrideIfExists: Boolean): Unit = synchronized {
if (!overrideIfExists && viewDefinitions.contains(name)) {
throw new TempTableAlreadyExistsException(name)
}
viewDefinitions.put(name, viewDefinition)
}
/**
* Updates the global temp view if it exists, returns true if updated, false otherwise.
*/
def update(
name: String,
viewDefinition: LogicalPlan): Boolean = synchronized {
if (viewDefinitions.contains(name)) {
viewDefinitions.put(name, viewDefinition)
true
} else {
false
}
}
/**
* Removes the global temp view if it exists, returns true if removed, false otherwise.
*/
def remove(name: String): Boolean = synchronized {
viewDefinitions.remove(name).isDefined
}
/**
* Renames the global temp view if the source view exists and the destination view not exists, or
* issue an exception if the source view exists but the destination view already exists. Returns
* true if renamed, false otherwise.
*/
def rename(oldName: String, newName: String): Boolean = synchronized {
if (viewDefinitions.contains(oldName)) {
if (viewDefinitions.contains(newName)) {
throw new AnalysisException(
s"rename temporary view from '$oldName' to '$newName': destination view already exists")
}
val viewDefinition = viewDefinitions(oldName)
viewDefinitions.remove(oldName)
viewDefinitions.put(newName, viewDefinition)
true
} else {
false
}
}
/**
* Lists the names of all global temporary views.
*/
def listViewNames(pattern: String): Seq[String] = synchronized {
StringUtils.filterPattern(viewDefinitions.keys.toSeq, pattern)
}
/**
* Clears all the global temporary views.
*/
def clear(): Unit = synchronized {
viewDefinitions.clear()
}
}