- ARPC - More Effective Network Communication
- Contents
- Features
- Performance
- Header Layout
- Installation
- Quick Start
- API Examples
- Register Routers
- Register Service Methods
- Router Middleware
- Coder Middleware
- Client Call, CallAsync, Notify
- Singleflight (Call De-duplication)
- Server Call, CallAsync, Notify
- Broadcast - Notify
- Async Response
- Handle New Connection
- Handle Disconnected
- Handle Client's send queue overstock
- Custom Net Protocol
- Custom Codec
- Custom Logger
- Custom operations before conn's recv and send
- Custom arpc.Client's Reader by wrapping net.Conn
- Custom arpc.Client's send queue capacity
- JS Client
- Web Chat Examples
- Pub/Sub Examples
- More Examples
- Two-Way Calling
- Two-Way Notify
- Sync and Async Calling
- Sync and Async Response
- Singleflight Call De-duplication
- Batch Write | Writev | net.Buffers
- Broadcast
- Middleware
- Pub/Sub
- Opentracing
| Pattern | Interactive Directions | Description |
|---|---|---|
| call | two-way: c -> s s -> c |
request and response |
| notify | two-way: c -> s s -> c |
request without response |
Here are some thirdparty benchmark including arpc, although these repos have provide the performance report, but I suggest you run the code yourself and get the real result, other than just believe other people's doc:
- LittleEndian
| bodyLen | reserved | cmd | flag | methodLen | sequence | method | body |
|---|---|---|---|---|---|---|---|
| 4 bytes | 1 byte | 1 byte | 1 bytes | 1 bytes | 8 bytes | methodLen bytes | bodyLen-methodLen bytes |
- Get and install arpc
$ go get -u github.com/lesismal/arpc- Import in your code:
import "github.com/lesismal/arpc"- start a server
package main
import "github.com/lesismal/arpc"
func main() {
server := arpc.NewServer()
// register router
server.Handler.Handle("/echo", func(ctx *arpc.Context) {
str := ""
if err := ctx.Bind(&str); err == nil {
ctx.Write(str)
}
})
server.Run("localhost:8888")
}- start a client
package main
import (
"log"
"net"
"time"
"github.com/lesismal/arpc"
)
func main() {
client, err := arpc.NewClient(func() (net.Conn, error) {
return net.DialTimeout("tcp", "localhost:8888", time.Second*3)
})
if err != nil {
panic(err)
}
defer client.Stop()
req := "hello"
rsp := ""
err = client.Call("/echo", &req, &rsp, time.Second*5)
if err != nil {
log.Fatalf("Call failed: %v", err)
} else {
log.Printf("Call Response: \"%v\"", rsp)
}
}var handler arpc.Handler
// package
handler = arpc.DefaultHandler
// server
handler = server.Handler
// client
handler = client.Handler
// message would be default handled one by one in the same conn reader goroutine
handler.Handle("/route", func(ctx *arpc.Context) { ... })
handler.Handle("/route2", func(ctx *arpc.Context) { ... })
// this make message handled by a new goroutine
async := true
handler.Handle("/asyncResponse", func(ctx *arpc.Context) { ... }, async)Instead of registering each route by hand, handler.Register(m, svc) reflects
over the struct value svc and registers all of its eligible methods at once,
each under the "Service.Method" route name m + "." + <MethodName> (or just
<MethodName> when m is empty). If no method is registered, Register panics.
There are two method shapes that Register recognizes:
- The first shape(a typed request/response method): an exported method with
the signature
func(ctx context.Context, req *Request, rsp *Response)and no return values, wherereq/rspare pointers to structs. - The second shape(an
arpc.HandlerFuncmethod): an exported method of typefunc(*arpc.Context).
Register handles three cases, summarized here and shown in the examples below:
| Case | Methods on the struct | Registered handler | Reflection at call time? | Performance |
|---|---|---|---|---|
| 1. First shape alone | Foo(ctx, req, rsp) only |
an auto-generated handler that news req/rsp, binds the request, calls Foo, then writes the response |
Yes — reflect.New + reflect.Value.Call on every request |
Slower |
| 2. Second shape alone | Bar(ctx *arpc.Context) only (any name, it does not have to end with Binding) |
the method itself | No — a plain function call | Fast |
| 3. Both, paired | Foo(ctx, req, rsp) + FooBinding(ctx *arpc.Context) |
the FooBinding method, registered under the route name Foo |
No — a plain function call | Fast |
Note:
Registeralways uses reflection while registering(a one-time cost at startup). The table above is about the call-time / per-request path: only case 1's auto-generated handler keeps using reflection on every request, so prefer case 2 or case 3 on hot paths.
In case 3 the two methods must be paired by name: the second method is named
<FirstMethodName>Binding. It is registered under the first method's name, and
lets you write the binding/response logic yourself instead of relying on the
reflection-based auto-generated handler.
type Echo struct{}
type EchoReq struct{ Message string }
type EchoRsp struct{ Message string }
// Case 1: first shape alone(no "HelloBinding"). Register auto-generates a
// reflection-based handler that binds the request, calls Hello and writes the
// response, registered as "Echo.Hello".
func (e *Echo) Hello(ctx context.Context, req *EchoReq, rsp *EchoRsp) {
rsp.Message = "hello, " + req.Message
}
// Case 2: second shape alone. A plain arpc.HandlerFunc method, registered as
// "Echo.Ping". The name need not end with "Binding".
func (e *Echo) Ping(ctx *arpc.Context) {
ctx.Write("pong")
}
// Case 3: paired. Say is the first shape, SayBinding is the second shape named
// after it. SayBinding is registered under the first method's name "Echo.Say",
// and the call path is a plain function call(no reflection).
// arpc.Context implements context.Context, so it can be passed through directly.
func (e *Echo) Say(ctx context.Context, req *EchoReq, rsp *EchoRsp) {
rsp.Message = req.Message
}
func (e *Echo) SayBinding(ctx *arpc.Context) {
req := &EchoReq{}
rsp := &EchoRsp{}
if err := ctx.Bind(req); err != nil {
ctx.Error(err)
return
}
e.Say(ctx, req, rsp)
ctx.Write(rsp)
}
var handler arpc.Handler
// package
handler = arpc.DefaultHandler
// server
handler = server.Handler
// client
handler = client.Handler
// registers "Echo.Hello"(case 1, auto-generated), "Echo.Ping"(case 2) and
// "Echo.Say"(case 3, via SayBinding)
if err := handler.Register("Echo", &Echo{}); err != nil {
log.Fatal(err)
}See router middleware, it's easy to implement middlewares yourself
import "github.com/lesismal/arpcex/extension/middleware/router"
var handler arpc.Handler
// package
handler = arpc.DefaultHandler
// server
handler = server.Handler
// client
handler = client.Handler
handler.Use(router.Recover())
handler.Use(router.Logger())
handler.Use(func(ctx *arpc.Context) { ... })
handler.Handle("/echo", func(ctx *arpc.Context) { ... })
handler.Use(func(ctx *arpc.Context) { ... })- Coder Middleware is used for converting a message data to your designed format, e.g encrypt/decrypt and compress/uncompress
import "github.com/lesismal/arpcex/extension/middleware/coder/gzip"
var handler arpc.Handler
// package
handler = arpc.DefaultHandler
// server
handler = server.Handler
// client
handler = client.Handler
handler.UseCoder(gzip.New())
handler.Handle("/echo", func(ctx *arpc.Context) { ... })- Call (Block, with timeout/context)
request := &Echo{...}
response := &Echo{}
timeout := time.Second*5
err := client.Call("/call/echo", request, response, timeout)
// ctx, cancel := context.WithTimeout(context.Background(), time.Second)
// defer cancel()
// err := client.CallWith(ctx, "/call/echo", request, response)- CallAsync (Nonblock, with callback and timeout/context)
request := &Echo{...}
timeout := time.Second*5
err := client.CallAsync("/call/echo", request, func(ctx *arpc.Context) {
response := &Echo{}
ctx.Bind(response)
...
}, timeout)- Notify (same as CallAsync with timeout/context, without callback)
data := &Notify{...}
client.Notify("/notify", data, time.Second)
// ctx, cancel := context.WithTimeout(context.Background(), time.Second)
// defer cancel()
// client.NotifyWith(ctx, "/notify", data)Enable singleflight on a router/method to de-duplicate concurrent calls: when
several goroutines call the same method with the same key at the same time,
only one request is actually sent to the server and all of them share its
response. This cuts duplicated round-trips and server load for hot, identical
requests. It applies to Call, CallContext/CallWith and CallAsync.
Only methods you register are optimized; every other method behaves exactly as before.
// Configure it on the Handler used by your Client (or use the package-level
// arpc.Singleflight(...) which applies to arpc.DefaultHandler).
// 1) Default key: req.String() when req implements fmt.Stringer,
// otherwise fmt.Sprintf("%v", req).
handler.Singleflight("/call/echo")
// 2) Or provide a custom func that computes the de-dup key from the req.
handler.Singleflight("/user/get", func(req interface{}) string {
return req.(*GetUserReq).ID
})
// Create the Client with that Handler, then call as usual; concurrent calls
// sharing the same key are collapsed into a single request.
client, _ := arpc.NewClient(dialer, handler)
err := client.Call("/call/echo", request, response, time.Second*5)Notes:
- The leader performs the real round-trip; followers wait for it and each
decodes the shared response into their own
rsp. The blocking path decodes the payload only once and shares the decoded value, so the shared response should be treated as read-only. - Every caller still honors its own timeout/context while waiting.
CallandCallContextde-duplicate together;CallAsyncde-duplicates within its own kind and each follower's callback is invoked with the shared response (or its own timeout).
- Get client and keep it in your application
var client *arpc.Client
server.Handler.Handle("/route", func(ctx *arpc.Context) {
client = ctx.Client
// release client
client.OnDisconnected(func(c *arpc.Client){
client = nil
})
})
go func() {
for {
time.Sleep(time.Second)
if client != nil {
client.Call(...)
client.CallAsync(...)
client.Notify(...)
}
}
}()- Then Call/CallAsync/Notify
var mux = sync.RWMutex{}
var clientMap = make(map[*arpc.Client]struct{})
func broadcast() {
var svr *arpc.Server = ...
msg := svr.NewMessage(arpc.CmdNotify, "/broadcast", fmt.Sprintf("broadcast msg %d", i))
mux.RLock()
for client := range clientMap {
client.PushMsg(msg, arpc.TimeZero)
}
mux.RUnlock()
}var handler arpc.Handler
// package
handler = arpc.DefaultHandler
// server
handler = server.Handler
// client
handler = client.Handler
asyncResponse := true // default is true, or set false
handler.Handle("/echo", func(ctx *arpc.Context) {
req := ...
err := ctx.Bind(req)
if err == nil {
ctx.Write(data)
}
}, asyncResponse)// package
arpc.DefaultHandler.HandleConnected(func(c *arpc.Client) {
...
})
// server
svr := arpc.NewServer()
svr.Handler.HandleConnected(func(c *arpc.Client) {
...
})
// client
client, err := arpc.NewClient(...)
client.Handler.HandleConnected(func(c *arpc.Client) {
...
})// package
arpc.DefaultHandler.HandleDisconnected(func(c *arpc.Client) {
...
})
// server
svr := arpc.NewServer()
svr.Handler.HandleDisconnected(func(c *arpc.Client) {
...
})
// client
client, err := arpc.NewClient(...)
client.Handler.HandleDisconnected(func(c *arpc.Client) {
...
})// package
arpc.DefaultHandler.HandleOverstock(func(c *arpc.Client) {
...
})
// server
svr := arpc.NewServer()
svr.Handler.HandleOverstock(func(c *arpc.Client) {
...
})
// client
client, err := arpc.NewClient(...)
client.Handler.HandleOverstock(func(c *arpc.Client) {
...
})// server
var ln net.Listener = ...
svr := arpc.NewServer()
svr.Serve(ln)
// client
dialer := func() (net.Conn, error) {
return ...
}
client, err := arpc.NewClient(dialer)import "github.com/lesismal/arpc/codec"
var codec arpc.Codec = ...
// package
codec.Defaultcodec = codec
// server
svr := arpc.NewServer()
svr.Codec = codec
// client
client, err := arpc.NewClient(...)
client.Codec = codecimport "github.com/lesismal/arpc/log"
var logger arpc.Logger = ...
log.SetLogger(logger) // log.DefaultLogger = loggerarpc.DefaultHandler.BeforeRecv(func(conn net.Conn) error) {
// ...
})
arpc.DefaultHandler.BeforeSend(func(conn net.Conn) error) {
// ...
})arpc.DefaultHandler.SetReaderWrapper(func(conn net.Conn) io.Reader) {
// ...
})arpc.DefaultHandler.SetSendQueueSize(4096)- See arpc.js
- See webchat
- start a server
import "github.com/lesismal/arpcex/extension/pubsub"
var (
address = "localhost:8888"
password = "123qwe"
topicName = "Broadcast"
)
func main() {
s := pubsub.NewServer()
s.Password = password
// server publish to all clients
go func() {
for i := 0; true; i++ {
time.Sleep(time.Second)
s.Publish(topicName, fmt.Sprintf("message from server %v", i))
}
}()
s.Run(address)
}- start a subscribe client
import "github.com/lesismal/arpc/log"
import "github.com/lesismal/arpcex/extension/pubsub"
var (
address = "localhost:8888"
password = "123qwe"
topicName = "Broadcast"
)
func onTopic(topic *pubsub.Topic) {
log.Info("[OnTopic] [%v] \"%v\", [%v]",
topic.Name,
string(topic.Data),
time.Unix(topic.Timestamp/1000000000, topic.Timestamp%1000000000).Format("2006-01-02 15:04:05.000"))
}
func main() {
client, err := pubsub.NewClient(func() (net.Conn, error) {
return net.DialTimeout("tcp", address, time.Second*3)
})
if err != nil {
panic(err)
}
client.Password = password
// authentication
err = client.Authenticate()
if err != nil {
panic(err)
}
// subscribe topic
if err := client.Subscribe(topicName, onTopic, time.Second); err != nil {
panic(err)
}
<-make(chan int)
}- start a publish client
import "github.com/lesismal/arpcex/extension/pubsub"
var (
address = "localhost:8888"
password = "123qwe"
topicName = "Broadcast"
)
func main() {
client, err := pubsub.NewClient(func() (net.Conn, error) {
return net.DialTimeout("tcp", address, time.Second*3)
})
if err != nil {
panic(err)
}
client.Password = password
// authentication
err = client.Authenticate()
if err != nil {
panic(err)
}
for i := 0; true; i++ {
if i%5 == 0 {
// publish msg to all clients
client.Publish(topicName, fmt.Sprintf("message from client %d", i), time.Second)
} else {
// publish msg to only one client
client.PublishToOne(topicName, fmt.Sprintf("message from client %d", i), time.Second)
}
time.Sleep(time.Second)
}
}- See examples