/*
* 对后端返回的ASK，重新向正确的后端发送
* r : 已经返回ASK的请求
*/
func (s *Session) handleAskRequest(r *Request) (*Request, error) {
// reset response
r.Response.Resp, r.Response.Err = nil, nil
usnow := microseconds()
s.LastOpUnix = usnow / 1e6
s.Ops++
// get hash key of the request
hkey := getHashKey(r.Resp, r.OpStr)
log.Infof("ASK: use key: %s to choose backend", string(hkey))
// create a asking request to backend
nr := &Request{
OpStr: "ASKING",
Start: usnow,
Resp: redis.NewString([]byte("ASKING")),
Wait: &sync.WaitGroup{},
Failed: &s.failed,
}
nr, err := s.handleRequestAsking(nr, hkey)
log.Infof("ASK: after dispatch asking request, waiting. error=%s", err)
if err != nil {
return r, err
} else {
s.GetTasks() <- nr
}
// resend the r to backend
err = s.GetDispather().Dispatch(r)
if err == nil {
s.GetTasks() <- r
}
return r, err
}
func (s *Session) handlePing(r *Request) (*Request, error) {
if len(r.Resp.Array) != 1 {
r.Response.Resp = redis.NewError([]byte("ERR wrong number of arguments for 'PING' command"))
return r, nil
}
r.Response.Resp = redis.NewString([]byte("PONG"))
return r, nil
}
func (s *Session) handleSelect(r *Request) (*Request, error) {
if len(r.Resp.Array) != 2 {
r.Response.Resp = redis.NewError([]byte("ERR wrong number of arguments for 'SELECT' command"))
return r, nil
}
if db, err := strconv.Atoi(string(r.Resp.Array[1].Value)); err != nil {
r.Response.Resp = redis.NewError([]byte("ERR invalid DB index"))
return r, nil
} else if db != 0 {
r.Response.Resp = redis.NewError([]byte("ERR invalid DB index, only accept DB 0"))
return r, nil
} else {
r.Response.Resp = redis.NewString([]byte("OK"))
return r, nil
}
}
func TestBackend(t *testing.T) {
l, err := net.Listen("tcp", "127.0.0.1:0")
assert.MustNoError(err)
defer l.Close()
addr := l.Addr().String()
reqc := make(chan *Request, 16384)
go func() {
bc := NewBackendConn(addr, "")
defer bc.Close()
defer close(reqc)
var resp = redis.NewBulkBytes(make([]byte, 4096))
for i := 0; i < cap(reqc); i++ {
r := &Request{
Resp: resp,
Wait: &sync.WaitGroup{},
}
bc.PushBack(r)
reqc <- r
}
}()
go func() {
c, err := l.Accept()
assert.MustNoError(err)
defer c.Close()
conn := redis.NewConn(c)
time.Sleep(time.Millisecond * 300)
for i := 0; i < cap(reqc); i++ {
_, err := conn.Reader.Decode()
assert.MustNoError(err)
resp := redis.NewString([]byte(strconv.Itoa(i)))
assert.MustNoError(conn.Writer.Encode(resp, true))
}
}()
var n int
for r := range reqc {
r.Wait.Wait()
assert.Must(string(r.Response.Resp.Value) == strconv.Itoa(n))
n++
}
assert.Must(n == cap(reqc))
}
func (s *Session) handleAuth(r *Request) (*Request, error) {
if len(r.Resp.Array) != 2 {
r.Response.Resp = redis.NewError([]byte("ERR wrong number of arguments for 'AUTH' command"))
return r, nil
}
if s.auth == "" {
r.Response.Resp = redis.NewError([]byte("ERR Client sent AUTH, but no password is set"))
return r, nil
}
if s.auth != string(r.Resp.Array[1].Value) {
s.authorized = false
r.Response.Resp = redis.NewError([]byte("ERR invalid password"))
return r, nil
} else {
s.authorized = true
r.Response.Resp = redis.NewString([]byte("OK"))
return r, nil
}
}
func (s *Session) handleQuit(r *Request) (*Request, error) {
s.quit = true
r.Response.Resp = redis.NewString([]byte("OK"))
return r, nil
}