Shixiong Zhu created SPARK-28456: ------------------------------------ Summary: Add a public API `Encoder.copyEncoder` to allow creating Encoder without touching Scala reflections Key: SPARK-28456 URL: https://issues.apache.org/jira/browse/SPARK-28456 Project: Spark Issue Type: New Feature Components: SQL Affects Versions: 2.4.3 Reporter: Shixiong Zhu Assignee: Shixiong Zhu
Because `Encoder` is not thread safe, the user cannot reuse an `Encoder` in multiple `Dataset`s. However, creating an `Encoder` for a complicated class is slow due to Scala reflections. To reduce the cost of Encoder creation, right now I usually use the private API `ExpressionEncoder.copy` as follows: {code} object FooEncoder { private lazy val _encoder: ExpressionEncoder[Foo] = ExpressionEncoder[Foo]() implicit def encoder: ExpressionEncoder[Foo] = _encoder.copy() } {code} This PR proposes a new method `copyEncoder` in `Encoder` so that the above codes can be rewritten using public APIs. {code} object FooEncoder { private lazy val _encoder: Encoder[Foo] = Encoders.product[Foo]() implicit def encoder: Encoder[Foo] = _encoder.copyEncoder() } {code} Regarding the method name, - Why not use `copy`? It conflicts with `case class`'s copy. - Why not use `clone`? It conflicts with `Object.clone`. -- This message was sent by Atlassian JIRA (v7.6.14#76016) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org