gedis implements a very low-level interface to read and write using the Redis protocol.
It also provides a simple client to talk to a Redis server and a generic Redis server, which allows you to implement your own server that understands the Redis protocol.
master branch status at Travis CI
gedis API documentation is available at the fabulous GoDoc website, in the following locations:
- Parser: http://godoc.org/github.com/inkel/gedis
- Server: http://godoc.org/github.com/inkel/gedis/server
- Client: http://godoc.org/github.com/inkel/gedis/client
You can find all the examples at https://github.com/inkel/gedis-examples
In this example we'll create net.Conn to a Redis server and we'll send commands by using the parser function gedis.Write, and then read the server's response by using gedis.Read:
package main
import (
"flag"
"fmt"
"github.com/inkel/gedis"
"net"
)
var server = flag.String("s", "localhost:6379", "Address of the Redis server")
func main() {
c, err := net.Dial("tcp", *server)
if err != nil {
panic(err)
}
defer c.Close()
f := func(args ...interface{}) {
cmd := args[0]
fmt.Printf("> %s", cmd)
for _, arg := range args[1:] {
fmt.Printf(" %q", arg)
}
fmt.Println()
// Send to command to Redis server
_, err := gedis.Write(c, args...)
if err != nil {
panic(err)
}
// Read the reply from the server
res, err := gedis.Read(c)
if err != nil {
panic(err)
}
fmt.Printf("< %#v\n\n", res)
}
f("PING")
f("SET", "lorem", "ipsum")
f("INCR", "counter")
f("HMSET", "hash", "field1", "lorem", "field2", "ipsum")
f("HGETALL", "hash")
}$ go run ./gedis.go
> PING
< "PONG"
> SET "lorem" "ipsum"
< "OK"
> INCR "counter"
< 6
> HMSET "hash" "field1" "lorem" "field2" "ipsum"
< "OK"
> HGETALL "hash"
< []interface {}{"field1", "lorem", "field2", "ipsum"}
You can also use the gedis client package to create a Client object that exposes almost the same API as using a net.Conn. In the future this client might add more features.
package main
import (
"flag"
"fmt"
"github.com/inkel/gedis/client"
)
var server = flag.String("s", "localhost:6379", "Address of the Redis server")
func main() {
c, err := client.Dial("tcp", *server)
if err != nil {
panic(err)
return
}
defer c.Close()
f := func(args ...interface{}) {
fmt.Printf("> %v\n", args)
// Send to command to Redis server
res, err := c.Send(args...)
if err != nil {
panic(err)
} else {
fmt.Printf("< %#v\n\n", res)
}
}
f("PING")
f("SET", "lorem", "ipsum")
f("INCR", "counter")
f("HMSET", "hash", "field1", "lorem", "field2", "ipsum")
f("HGETALL", "hash")
f("MULTI")
f("GET", "counter")
f("GET", "nonexisting")
f("EXEC")
}$ go run ./client.go
> [PING]
< "PONG"
> [SET lorem ipsum]
< "OK"
> [INCR counter]
< 7
> [HMSET hash field1 lorem field2 ipsum]
< "OK"
> [HGETALL hash]
< []interface {}{"field1", "lorem", "field2", "ipsum"}
> [MULTI]
< "OK"
> [GET counter]
< "QUEUED"
> [GET nonexisting]
< "QUEUED"
> [EXEC]
< []interface {}{"7", interface {}(nil)}
If you want to build a custom server that understands the Redis protocol, you can use the Server type defined in the gedis server namespace.
The following example implements a server that only responds to the PING command:
package main
import (
"flag"
"fmt"
"github.com/inkel/gedis/server"
"os"
"os/signal"
)
var listen = flag.String("l", ":26379", "Address to listen for connections")
func main() {
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt, os.Kill)
s, err := server.NewServer("tcp", *listen)
if err != nil {
panic(err)
}
defer s.Close()
pong := []byte("+PONG\r\n")
earg := []byte("-ERR wrong number of arguments for 'ping' command\r\n")
s.Handle("PING", func(c *server.Client, args [][]byte) error {
if len(args) != 0 {
c.Write(earg)
return nil
} else {
c.Write(pong)
}
return nil
})
go s.Loop()
// Wait for interrupt/kill
<-c
fmt.Println("Bye!")
}$ go run ./server.go &
$ redis-cli -p 26379
redis 127.0.0.1:26379> ping
PONG
redis 127.0.0.1:26379> get inkel
(error) ERR Unrecognized command 'get'
redis 127.0.0.1:26379>
This generic server performs quite well, though not as fast as the standard C Redis server (which is kind of obvious):
$ redis-benchmark -q -t PING_MBULK -p 26379
PING_BULK: 36630.04 requests per second
In your $GOPATH do the following:
go get github.com/inkel/gedis
go get github.com/inkel/gedis/client
go get github.com/inkel/gedis/server
Then you can build it by executing:
go build github.com/inkel/gedis
go build github.com/inkel/gedis/client
go build github.com/inkel/gedis/server
Testing and benchmark:
go test github.com/inkel/gedis
go test github.com/inkel/gedis -bench=".*"
go test github.com/inkel/gedis/client
go test github.com/inkel/gedis/client -bench=".*"
go test github.com/inkel/gedis/server
go test github.com/inkel/gedis/server -bench=".*"
I wanted to learn Go, so I decided to write a minimal Redis client.
Perhaps one day I might decide to do something else with it, but in the mean, the goals are merely academic.
Feel free to comment on the code and send patches if you like.
Copyright (c) 2013 Leandro López
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