measure/src/main/scala/org/apache/griffin/measure/context/TableRegister.scala

/*
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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
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specific language governing permissions and limitations
under the License.
*/
package org.apache.griffin.measure.context

import scala.collection.mutable.{Set => MutableSet}

import org.apache.spark.sql._

import org.apache.griffin.measure.Loggable


/**
  * register table name
  */
trait TableRegister extends Loggable with Serializable {

  protected val tables: MutableSet[String] = MutableSet()

  def registerTable(name: String): Unit = {
    tables += name
  }

  def existsTable(name: String): Boolean = {
    tables.exists(_.equals(name))
  }

  def unregisterTable(name: String): Unit = {
    if (existsTable(name)) tables -= name
  }
  def unregisterAllTables(): Unit = {
    tables.clear
  }

  def getTables(): Set[String] = {
    tables.toSet
  }

}

/**
  * register table name when building dq job
  */
case class CompileTableRegister() extends TableRegister {}

/**
  * register table name and create temp view during calculation
  */
case class RunTimeTableRegister(@transient sparkSession: SparkSession) extends TableRegister {

  def registerTable(name: String, df: DataFrame): Unit = {
    registerTable(name)
    df.createOrReplaceTempView(name)
  }

  override def unregisterTable(name: String): Unit = {
    if (existsTable(name)) {
      sparkSession.catalog.dropTempView(name)
      tables -= name
    }
  }
  override def unregisterAllTables(): Unit = {
    val uts = getTables
    uts.foreach(t => sparkSession.catalog.dropTempView(t))
    tables.clear
  }

}