Refactor the bitcaskd (redis compatible server) sample to improve code quality (#88)

cmd/bitcaskd/server.go

@@ -0,0 +1,122 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/tidwall/redcon"
+
+	"github.com/prologic/bitcask"
+)
+
+type server struct {
+	bind string
+	db   *bitcask.Bitcask
+}
+
+func newServer(bind, dbpath string) (*server, error) {
+	db, err := bitcask.Open(dbpath)
+	if err != nil {
+		log.WithError(err).WithField("dbpath", dbpath).Error("error opening database")
+		return nil, err
+	}
+
+	return &server{
+		bind: bind,
+		db:   db,
+	}, nil
+}
+
+func (s *server) handleSet(cmd redcon.Command, conn redcon.Conn) {
+	if len(cmd.Args) != 3 {
+		conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
+		return
+	}
+	key := cmd.Args[1]
+	value := cmd.Args[2]
+	if err := s.db.Put(key, value); err != nil {
+		conn.WriteString(fmt.Sprintf("ERR: %s", err))
+	} else {
+		conn.WriteString("OK")
+	}
+}
+
+func (s *server) handleGet(cmd redcon.Command, conn redcon.Conn) {
+	if len(cmd.Args) != 2 {
+		conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
+		return
+	}
+	key := cmd.Args[1]
+	value, err := s.db.Get(key)
+	if err != nil {
+		conn.WriteNull()
+	} else {
+		conn.WriteBulk(value)
+	}
+}
+
+func (s *server) handleKeys(cmd redcon.Command, conn redcon.Conn) {
+	conn.WriteArray(s.db.Len())
+	for key := range s.db.Keys() {
+		conn.WriteBulk([]byte(key))
+	}
+}
+
+func (s *server) handleExists(cmd redcon.Command, conn redcon.Conn) {
+	if len(cmd.Args) != 2 {
+		conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
+		return
+	}
+	key := cmd.Args[1]
+	if s.db.Has(key) {
+		conn.WriteInt(1)
+	} else {
+		conn.WriteInt(0)
+	}
+}
+
+func (s *server) handleDel(cmd redcon.Command, conn redcon.Conn) {
+	if len(cmd.Args) != 2 {
+		conn.WriteError("ERR wrong number of arguments for '" + string(cmd.Args[0]) + "' command")
+		return
+	}
+	key := cmd.Args[1]
+	if err := s.db.Delete(key); err != nil {
+		conn.WriteInt(0)
+	} else {
+		conn.WriteInt(1)
+	}
+}
+
+func (s *server) Run() (err error) {
+	err = redcon.ListenAndServe(s.bind,
+		func(conn redcon.Conn, cmd redcon.Command) {
+			switch strings.ToLower(string(cmd.Args[0])) {
+			case "ping":
+				conn.WriteString("PONG")
+			case "quit":
+				conn.WriteString("OK")
+				conn.Close()
+			case "set":
+				s.handleSet(cmd, conn)
+			case "get":
+				s.handleGet(cmd, conn)
+			case "keys":
+				s.handleKeys(cmd, conn)
+			case "exists":
+				s.handleExists(cmd, conn)
+			case "del":
+				s.handleDel(cmd, conn)
+			default:
+				conn.WriteError("ERR unknown command '" + string(cmd.Args[0]) + "'")
+			}
+		},
+		func(conn redcon.Conn) bool {
+			return true
+		},
+		func(conn redcon.Conn, err error) {
+		},
+	)
+	return
+}