PJ Fanning created DRILL-8431:
---------------------------------
Summary: add immutable wrapper for ObjectMapper
Key: DRILL-8431
URL: https://issues.apache.org/jira/browse/DRILL-8431
Project: Apache Drill
Issue Type: Task
Components: Server
Reporter: PJ Fanning
The Jackson based code in Drill is quite complicated and passes around
ObjectMapper instances in a way that is difficult to maintain.
We need to balance the objective of trying to reuse ObjectMapper instances
(because they are fairly expensive to create) but avoid the risk that code
modifies an ObjectMapper instance (extra config or extra modules added) in a
way that affects other code that uses the ObjectMapper instance.
Jackson 3 (which is under development but a long way off) moves towards making
ObjectMappers immutable. Mapper Builders are used instead to configure mappers.
Some of these API changes are already backported to Jackson 2.
My suggestion in this Jira is that we create a new Drill class called
ImmutableObjectMapper and this exposes API methods for reading and writing JSON
but that hides methods for configuring the mapper. We can wrap some of our
ObjectMappers. It will probably take a few iterations to get everything
switched over but we can start with the low hanging fruit.
This class would allow the Java compiler to check for any untidy attempts to
modify an ObjectMapper that was created elsewhere.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
