org.apache.spark.sql.types.MapType.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.types
import org.json4s.JsonAST.JValue
import org.json4s.JsonDSL._
import org.apache.spark.annotation.InterfaceStability
/**
* The data type for Maps. Keys in a map are not allowed to have `null` values.
*
* Please use `DataTypes.createMapType()` to create a specific instance.
*
* @param keyType The data type of map keys.
* @param valueType The data type of map values.
* @param valueContainsNull Indicates if map values have `null` values.
*/
@InterfaceStability.Stable
case class MapType(
keyType: DataType,
valueType: DataType,
valueContainsNull: Boolean) extends DataType {
/** No-arg constructor for kryo. */
def this() = this(null, null, false)
private[sql] def buildFormattedString(prefix: String, builder: StringBuilder): Unit = {
builder.append(s"$prefix-- key: ${keyType.typeName}\n")
DataType.buildFormattedString(keyType, s"$prefix |", builder)
builder.append(s"$prefix-- value: ${valueType.typeName} " +
s"(valueContainsNull = $valueContainsNull)\n")
DataType.buildFormattedString(valueType, s"$prefix |", builder)
}
override private[sql] def jsonValue: JValue =
("type" -> typeName) ~
("keyType" -> keyType.jsonValue) ~
("valueType" -> valueType.jsonValue) ~
("valueContainsNull" -> valueContainsNull)
/**
* The default size of a value of the MapType is
* (the default size of the key type + the default size of the value type).
* We assume that there is only 1 element on average in a map. See SPARK-18853.
*/
override def defaultSize: Int = 1 * (keyType.defaultSize + valueType.defaultSize)
override def simpleString: String = s"map<${keyType.simpleString},${valueType.simpleString}>"
override def catalogString: String = s"map<${keyType.catalogString},${valueType.catalogString}>"
override def sql: String = s"MAP<${keyType.sql}, ${valueType.sql}>"
override private[spark] def asNullable: MapType =
MapType(keyType.asNullable, valueType.asNullable, valueContainsNull = true)
override private[spark] def existsRecursively(f: (DataType) => Boolean): Boolean = {
f(this) || keyType.existsRecursively(f) || valueType.existsRecursively(f)
}
}
/**
* @since 1.3.0
*/
@InterfaceStability.Stable
object MapType extends AbstractDataType {
override private[sql] def defaultConcreteType: DataType = apply(NullType, NullType)
override private[sql] def acceptsType(other: DataType): Boolean = {
other.isInstanceOf[MapType]
}
override private[sql] def simpleString: String = "map"
/**
* Construct a [[MapType]] object with the given key type and value type.
* The `valueContainsNull` is true.
*/
def apply(keyType: DataType, valueType: DataType): MapType =
MapType(keyType: DataType, valueType: DataType, valueContainsNull = true)
}