mirror of https://github.com/minio/minio.git
83 lines
2.7 KiB
Go
83 lines
2.7 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
|
|
// Copyright 2012 The Gorilla Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// Copyright 2020 MinIO, Inc. All rights reserved.
|
|
// forked from https://github.com/gorilla/rpc/v2
|
|
// modified to be used with MinIO under Apache
|
|
// 2.0 license that can be found in the LICENSE file.
|
|
|
|
/*
|
|
Package gorilla/rpc is a foundation for RPC over HTTP services, providing
|
|
access to the exported methods of an object through HTTP requests.
|
|
|
|
This package derives from the standard net/rpc package but uses a single HTTP
|
|
request per call instead of persistent connections. Other differences
|
|
compared to net/rpc:
|
|
|
|
- Multiple codecs can be registered in the same server.
|
|
- A codec is chosen based on the "Content-Type" header from the request.
|
|
- Service methods also receive http.Request as parameter.
|
|
- This package can be used on Google App Engine.
|
|
|
|
Let's setup a server and register a codec and service:
|
|
|
|
import (
|
|
"http"
|
|
"github.com/minio/minio/pkg/rpc/"
|
|
"github.com/minio/minio/pkg/rpc/json2"
|
|
)
|
|
|
|
func init() {
|
|
s := rpc.NewServer()
|
|
s.RegisterCodec(json2.NewCodec(), "application/json")
|
|
s.RegisterService(new(HelloService), "")
|
|
http.Handle("/rpc", s)
|
|
}
|
|
|
|
This server handles requests to the "/rpc" path using a JSON codec.
|
|
A codec is tied to a content type. In the example above, the JSON codec is
|
|
registered to serve requests with "application/json" as the value for the
|
|
"Content-Type" header. If the header includes a charset definition, it is
|
|
ignored; only the media-type part is taken into account.
|
|
|
|
A service can be registered using a name. If the name is empty, like in the
|
|
example above, it will be inferred from the service type.
|
|
|
|
That's all about the server setup. Now let's define a simple service:
|
|
|
|
type HelloArgs struct {
|
|
Who string
|
|
}
|
|
|
|
type HelloReply struct {
|
|
Message string
|
|
}
|
|
|
|
type HelloService struct {}
|
|
|
|
func (h *HelloService) Say(r *http.Request, args *HelloArgs, reply *HelloReply) error {
|
|
reply.Message = "Hello, " + args.Who + "!"
|
|
return nil
|
|
}
|
|
|
|
The example above defines a service with a method "HelloService.Say" and
|
|
the arguments and reply related to that method.
|
|
|
|
The service must be exported (begin with an upper case letter) or local
|
|
(defined in the package registering the service).
|
|
|
|
When a service is registered, the server inspects the service methods
|
|
and make available the ones that follow these rules:
|
|
|
|
- The method name is exported.
|
|
- The method has three arguments: *http.Request, *args, *reply.
|
|
- All three arguments are pointers.
|
|
- The second and third arguments are exported or local.
|
|
- The method has return type error.
|
|
|
|
All other methods are ignored.
|
|
*/
|
|
package rpc
|