Thrift Package for Go
API Documentation: http://godoc.org/github.com/samuel/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.
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 "cmd/go-thrift"
contains a Go code generator. It could be extended to include other
languages.
How to use the generator:
$ go install github.com/alecthomas/go-thrift/cmd/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.pointers
Make all fields pointers
-go.signedbytes
Interpret Thrift byte as Go signed int8 type
$ go-thrift cassandra.thrift $GOPATH/src/
TODO
- default values
- oneway requests on the server