measure/src/main/scala/org/apache/griffin/measure/step/read/ReadStep.scala

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regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
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  http://www.apache.org/licenses/LICENSE-2.0

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package org.apache.griffin.measure.step.read

import org.apache.spark.sql._

import org.apache.griffin.measure.context.DQContext
import org.apache.griffin.measure.step.DQStep

trait ReadStep extends DQStep {

  val config: Map[String, Any]

  val cache: Boolean

  def execute(context: DQContext): Boolean = {
    info(s"read data source [${name}]")
    read(context) match {
      case Some(df) =>
//        if (needCache) context.dataFrameCache.cacheDataFrame(name, df)
        context.runTimeTableRegister.registerTable(name, df)
        true
      case _ =>
        warn(s"read data source [${name}] fails")
        false
    }
  }

  def read(context: DQContext): Option[DataFrame]

}