/
undis.go
100 lines (82 loc) · 2.49 KB
/
undis.go
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package main
import (
"flag"
"fmt"
"net"
"os"
"redisio"
)
const (
defaultListenAddr = "localhost:6378"
defaultRedisAddr = "localhost:6379"
)
func main() {
var (
listener net.Listener
err error
)
flag.Parse()
listenAddr := defaultListenAddr
redisAddr := defaultRedisAddr
// TODO: change this to take args
fmt.Printf("Listening on %s\n", listenAddr)
fmt.Printf("Connects to %s\n", redisAddr)
if listener, err = net.Listen("tcp", listenAddr); listener == nil {
fmt.Fprintf(os.Stderr, "Cannot listen: %v\n", err)
os.Exit(1)
}
for {
if conn, err := listener.Accept(); conn == nil {
fmt.Fprintf(os.Stderr, "connect: %v\n", err)
os.Exit(1)
} else {
fmt.Printf("Accepted connection\n")
go proxy(conn, redisAddr)
}
}
}
// proxies from client to server
func cmdLoop(cmdReader *redisio.Reader, cmdWriter *redisio.Writer) {
for {
if command, err := cmdReader.ReadCommand(); err != nil {
fmt.Fprintf(os.Stderr, "redis read command failed: %v\n", err)
return
} else {
fmt.Printf("Command: %v\n", command)
if err = cmdWriter.WriteCommand(command); err != nil {
fmt.Fprintf(os.Stderr, "redis write command failed: %v\n", err)
return
}
cmdWriter.Flush()
}
}
}
func replyLoop(replyReader *redisio.Reader, replyWriter *redisio.Writer) {
for {
if reply, err := replyReader.ReadReply(); err != nil {
fmt.Fprintf(os.Stderr, "redis read reply failed: %v\n", err)
return
} else {
fmt.Printf("Reply: %v\n", reply)
if err = replyWriter.WriteReply(reply); err != nil {
fmt.Fprintf(os.Stderr, "redis write reply failed: %v\n", err)
return
}
replyWriter.Flush()
}
}
}
func proxy(in net.Conn, redisAddr string) {
if out, err := net.Dial("tcp", redisAddr); out == nil {
fmt.Fprintf(os.Stderr, "outgoing connection failed: %v\n", err)
return
} else {
fmt.Printf("Established outgoing connection\n")
cmdReader := redisio.NewReader(in)
cmdWriter := redisio.NewWriter(out)
replyReader := redisio.NewReader(out)
replyWriter := redisio.NewWriter(in)
go replyLoop(replyReader, replyWriter)
go cmdLoop(cmdReader, cmdWriter)
}
}