CODEWITHSUNDEEP
reflectionthrift
Igor Gatis
Igor Gatis

Reputation: 4898

Does Apache Thrift provide reflection API?

Does thrift provide a way to inspect struct fields at runtime?

My use case is with C# but the question is regarding the standard Thrift API.

Upvotes: 5

Views: 1785

Answers (2)

JT.
JT.

Reputation: 633

There is no standard thrift API across languages so what you can do beyond serialization is highly language dependent. If you can't accomplish what you want using just reflection, examine the code that is generated by the thrift compiler for the thrift object you are interested in. I've not seen C# thrift generated code but it may contain additional data that could be useful to you.

I am very familiar with the Java implementation and I can tell you that using thrift with Java there is no need to use reflection at all. Every thrift generated class contains information that allows the deserializer to reconstruct the class from field id numbers. The java thrift compiler creates static members and methods which contain pretty much everything you would ever want. For Java it is actually better than reflection because it contains the element types for lists/maps/sets.

Now there is no guarantee that the formats of this data won't change in future versions of thrift but given that all of the various protocols depend on them the 'hidden' API should be fairly stable.

Upvotes: 1

BCG
BCG

Reputation: 1170

If you have access to the IDL at runtime you could use a parser for the IDL and infer the generated fields that way.

I'm not an expert in C# but you could maybe link to the native libparse library used in the Thrift executable (I'm not sure if the parse library is generic enough to use like that, I'm just assuming).

Alternatively you could use the parser from Facebook's Swift (https://github.com/facebook/swift/tree/master/swift-idl-parser, or download the JAR from http://central.maven.org/maven2/com/facebook/swift/swift-idl-parser/0.13.2/swift-idl-parser-0.13.2.jar). This is probably easier or better for your case IMO, even though it is a Java library I think it should convert just fine to CLR using IKVM.net.

A third stupidly simple and hackish way to do this would be to use the Thrift HTML generator to generate HTML documentation and parse that using regex or run it through HTML Tidy and parse it as XML

Upvotes: 0

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