go-thrift

README

Thrift Package for Go

API Documentation: http://godoc.org/github.com/andeya/go-thrift

License

3-clause BSD. See LICENSE file.

Overview

Thrift is an IDL that can be used to generate RPC client and server bindings for a variety of languages. This package includes client and server codecs, serialization, and code generation for Go. It tries to be a more natural mapping to the language compared to other implementations. For instance, Go already has the idea of a thrift transport in the ReadWriteCloser interfaces.

Types

Most types map directly to the native Go types, but there are some quirks and limitations.

• Go supports a more limited set of types for map keys than Thrift

• To use a set define the field as []type and provide a tag of "set":

    StringSet []string `thrift:"1,set"`
  

• []byte get encoded/decoded as a string because the Thrift binary type is the same as string on the wire.

• Go supports go.tag annotation to define the field tag

    1: Int32 b (go.tag="json:\"b_field\" xml:\"BField\"")
    ->
    B *int32 `thrift:"1,required" json:"b_field" xml:"BField"`
  

RPC

The standard Go net/rpc package is used to provide RPC. Although, one incompatibility is the net/rpc's use of ServiceName.Method for naming RPC methods. To get around this the Thrift ServerCodec prefixes method names with "Thrift".

Transport

There are no specific transport "classes" as there are in most Thrift libraries. Instead, the standard io.ReadWriteCloser is used as the interface. If the value also implements the thrift.Flusher interface then Flush() error is called after protocol.WriteMessageEnd.

Framed transport is supported by wrapping a value implementing io.ReadWriteCloser with thrift.NewFramedReadWriteCloser(value)

One-way requests

Client

One-way request support needs to be enabled on the RPC codec explicitly. The reason they're not allowed by default is because the Go RPC package doesn't actually support one-way requests. To get around this requires a rather janky hack of using channels to track pending requests in the codec and faking responses.

Server

One-way requests aren't yet implemented on the server side.

Parser & Code Generator

The "parser" subdirectory contains a Thrift IDL parser, and "generator" contains a Go code generator. It could be extended to include other languages.

How to use the go-thrift:

$ go install github.com/andeya/go-thrift/go-thrift

$ go-thrift --help
Usage of generator:
  -go.binarystring
        Always use string for binary instead of []byte
  -go.importprefix string
        Prefix for Thrift-generated go package imports
  -go.json.enumnum
        For JSON marshal enums by number instead of name
  -go.norpc
        RPC code is not generated
  -go.pointers
        Make all fields pointers
  -go.signedbytes
        Interpret Thrift byte as Go signed int8 type

$ generator cassandra.thrift $GOPATH/src/

Regenerate Parser

Provided you have Go correctly installed with the $GOPATH and $GOBIN environment variables set, run:

GO111MODULE=off go get -u github.com/mna/pigeon
GO111MODULE=off go get golang.org/x/tools/cmd/goimports
cd parser
go generate

TODO

• default values
• oneway requests on the server