org.apache.spark.sql.execution.datasources.v2.DataSourceReaderHolder.scala Maven / Gradle / Ivy
/*
* 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
import java.util.Objects
import org.apache.spark.sql.catalyst.expressions.Attribute
import org.apache.spark.sql.sources.v2.reader._
/**
* A base class for data source reader holder with customized equals/hashCode methods.
*/
trait DataSourceReaderHolder {
/**
* The output of the data source reader, w.r.t. column pruning.
*/
def output: Seq[Attribute]
/**
* The held data source reader.
*/
def reader: DataSourceReader
/**
* The metadata of this data source reader that can be used for equality test.
*/
private def metadata: Seq[Any] = {
val filters: Any = reader match {
case s: SupportsPushDownCatalystFilters => s.pushedCatalystFilters().toSet
case s: SupportsPushDownFilters => s.pushedFilters().toSet
case _ => Nil
}
Seq(output, reader.getClass, filters)
}
def canEqual(other: Any): Boolean
override def equals(other: Any): Boolean = other match {
case other: DataSourceReaderHolder =>
canEqual(other) && metadata.length == other.metadata.length &&
metadata.zip(other.metadata).forall { case (l, r) => l == r }
case _ => false
}
override def hashCode(): Int = {
metadata.map(Objects.hashCode).foldLeft(0)((a, b) => 31 * a + b)
}
}