spark CSVPartitionReaderFactory 源码
spark CSVPartitionReaderFactory 代码
文件路径:/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/csv/CSVPartitionReaderFactory.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
*
* 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.execution.datasources.v2.csv
import org.apache.spark.broadcast.Broadcast
import org.apache.spark.sql.catalyst.InternalRow
import org.apache.spark.sql.catalyst.csv.{CSVHeaderChecker, CSVOptions, UnivocityParser}
import org.apache.spark.sql.connector.read.PartitionReader
import org.apache.spark.sql.execution.datasources.PartitionedFile
import org.apache.spark.sql.execution.datasources.csv.CSVDataSource
import org.apache.spark.sql.execution.datasources.v2._
import org.apache.spark.sql.internal.SQLConf
import org.apache.spark.sql.sources.Filter
import org.apache.spark.sql.types.StructType
import org.apache.spark.util.SerializableConfiguration
/**
* A factory used to create CSV readers.
*
* @param sqlConf SQL configuration.
* @param broadcastedConf Broadcasted serializable Hadoop Configuration.
* @param dataSchema Schema of CSV files.
* @param readDataSchema Required data schema in the batch scan.
* @param partitionSchema Schema of partitions.
* @param options Options for parsing CSV files.
*/
case class CSVPartitionReaderFactory(
sqlConf: SQLConf,
broadcastedConf: Broadcast[SerializableConfiguration],
dataSchema: StructType,
readDataSchema: StructType,
partitionSchema: StructType,
options: CSVOptions,
filters: Seq[Filter]) extends FilePartitionReaderFactory {
override def buildReader(file: PartitionedFile): PartitionReader[InternalRow] = {
val conf = broadcastedConf.value.value
val actualDataSchema = StructType(
dataSchema.filterNot(_.name == options.columnNameOfCorruptRecord))
val actualReadDataSchema = StructType(
readDataSchema.filterNot(_.name == options.columnNameOfCorruptRecord))
val parser = new UnivocityParser(
actualDataSchema,
actualReadDataSchema,
options,
filters)
val schema = if (options.columnPruning) actualReadDataSchema else actualDataSchema
val isStartOfFile = file.start == 0
val headerChecker = new CSVHeaderChecker(
schema, options, source = s"CSV file: ${file.filePath}", isStartOfFile)
val iter = CSVDataSource(options).readFile(
conf,
file,
parser,
headerChecker,
readDataSchema)
val fileReader = new PartitionReaderFromIterator[InternalRow](iter)
new PartitionReaderWithPartitionValues(fileReader, readDataSchema,
partitionSchema, file.partitionValues)
}
}
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