integration/spark2/src/main/scala/org/apache/spark/sql/CarbonCountStar.scala

/*
 * 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
 *
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * See the License for the specific language governing permissions and
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package org.apache.spark.sql

import scala.collection.JavaConverters._

import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.fs.Path
import org.apache.hadoop.mapred.JobConf
import org.apache.hadoop.mapreduce.Job
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat
import org.apache.spark.deploy.SparkHadoopUtil
import org.apache.spark.rdd.RDD
import org.apache.spark.sql.catalyst.{InternalRow, TableIdentifier}
import org.apache.spark.sql.catalyst.expressions._
import org.apache.spark.sql.execution.LeafExecNode
import org.apache.spark.sql.optimizer.CarbonFilters

import org.apache.carbondata.core.metadata.AbsoluteTableIdentifier
import org.apache.carbondata.core.metadata.schema.table.CarbonTable
import org.apache.carbondata.core.mutate.CarbonUpdateUtil
import org.apache.carbondata.hadoop.api.{CarbonInputFormat, CarbonTableInputFormat}

case class CarbonCountStar(
    attributesRaw: Seq[Attribute],
    carbonTable: CarbonTable,
    sparkSession: SparkSession,
    outUnsafeRows: Boolean = true) extends LeafExecNode {

  override def doExecute(): RDD[InternalRow] = {
    val absoluteTableIdentifier = carbonTable.getAbsoluteTableIdentifier
    val (job, tableInputFormat) = createCarbonInputFormat(absoluteTableIdentifier)
    CarbonInputFormat.setQuerySegment(job.getConfiguration, absoluteTableIdentifier)

    // get row count
    val rowCount = CarbonUpdateUtil.getRowCount(
      tableInputFormat.getBlockRowCount(
        job,
        absoluteTableIdentifier,
        CarbonFilters.getPartitions(
          Seq.empty,
          sparkSession,
          TableIdentifier(
            carbonTable.getTableName,
            Some(carbonTable.getDatabaseName))).map(_.asJava).orNull),
      absoluteTableIdentifier)
    val value = new GenericInternalRow(Seq(Long.box(rowCount)).toArray.asInstanceOf[Array[Any]])
    val unsafeProjection = UnsafeProjection.create(output.map(_.dataType).toArray)
    val row = if (outUnsafeRows) unsafeProjection(value) else value
    sparkContext.parallelize(Seq(row))
  }

  override def output: Seq[Attribute] = {
    attributesRaw
  }

  private def createCarbonInputFormat(absoluteTableIdentifier: AbsoluteTableIdentifier
  ): (Job, CarbonTableInputFormat[Array[Object]]) = {
    val carbonInputFormat = new CarbonTableInputFormat[Array[Object]]()
    val jobConf: JobConf = new JobConf(new Configuration)
    SparkHadoopUtil.get.addCredentials(jobConf)
    val job = new Job(jobConf)
    FileInputFormat.addInputPath(job, new Path(absoluteTableIdentifier.getTablePath))
    (job, carbonInputFormat)
  }
}