Github user marmbrus commented on a diff in the pull request:
https://github.com/apache/spark/pull/5498#discussion_r28470212
--- Diff:
sql/core/src/main/scala/org/apache/spark/sql/jdbc/DriverQuirks.scala ---
@@ -39,33 +39,68 @@ import java.sql.Types
* if `getJDBCType` returns `(null, None)`, the default type handling is
used
* for the given Catalyst type.
*/
-private[sql] abstract class DriverQuirks {
+abstract class DriverQuirks {
+ def canHandle(url : String): Boolean
def getCatalystType(sqlType: Int, typeName: String, size: Int, md:
MetadataBuilder): DataType
def getJDBCType(dt: DataType): (String, Option[Int])
}
-private[sql] object DriverQuirks {
+object DriverQuirks {
+
+ private var quirks = List[DriverQuirks]()
+
+ def registerQuirks(quirk: DriverQuirks) : Unit = {
+ quirks = quirk :: quirks
+ }
+
+ def unregisterQuirks(quirk : DriverQuirks) : Unit = {
+ quirks = quirks.filterNot(_ == quirk)
+ }
+
+ registerQuirks(new MySQLQuirks())
+ registerQuirks(new PostgresQuirks())
+
/**
* Fetch the DriverQuirks class corresponding to a given database url.
*/
def get(url: String): DriverQuirks = {
- if (url.substring(0, 10).equals("jdbc:mysql")) {
- new MySQLQuirks()
- } else if (url.substring(0, 15).equals("jdbc:postgresql")) {
- new PostgresQuirks()
- } else {
- new NoQuirks()
+ val matchingQuirks = quirks.filter(_.canHandle(url))
+ matchingQuirks.length match {
+ case 0 => new NoQuirks()
+ case 1 => matchingQuirks.head
+ case _ => new AggregatedQuirks(matchingQuirks)
}
}
}
-private[sql] class NoQuirks extends DriverQuirks {
+class AggregatedQuirks(quirks: List[DriverQuirks]) extends DriverQuirks {
+
+ require(!quirks.isEmpty)
+
+ def canHandle(url : String): Boolean =
+ quirks.map(_.canHandle(url)).reduce(_ && _)
+
+ def getCatalystType(sqlType: Int, typeName: String, size: Int, md:
MetadataBuilder): DataType =
+ quirks.map(_.getCatalystType(sqlType, typeName, size,
md)).collectFirst {
+ case dataType if dataType != null => dataType
+ }.orNull
+
+ def getJDBCType(dt: DataType): (String, Option[Int]) =
+ quirks.map(_.getJDBCType(dt)).collectFirst {
+ case t @ (typeName,sqlType) if typeName != null || sqlType.isDefined
=> t
+ }.getOrElse((null, None))
+
+}
+
+class NoQuirks extends DriverQuirks {
+ def canHandle(url : String): Boolean = true
def getCatalystType(sqlType: Int, typeName: String, size: Int, md:
MetadataBuilder): DataType =
null
def getJDBCType(dt: DataType): (String, Option[Int]) = (null, None)
}
-private[sql] class PostgresQuirks extends DriverQuirks {
+class PostgresQuirks extends DriverQuirks {
--- End diff --
Should these be `case object`s?
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