/
redis.go
163 lines (136 loc) · 3.31 KB
/
redis.go
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package redis
import (
"context"
"errors"
"net"
"runtime/debug"
"sync"
"time"
)
type contextKey struct {
name string
}
var (
ServerContextKey = &contextKey{"redis-server"}
LocalAddrContextKey = &contextKey{"local-addr"}
ErrServerClosed = errors.New("redis: Server closed")
shutdownPollInterval = 500 * time.Millisecond
)
type Handler interface {
ServeRedis(context.Context, ResponseWriter, *Request)
}
type HandlerFunc func(context.Context, ResponseWriter, *Request)
func (f HandlerFunc) ServeRedis(ctx context.Context, w ResponseWriter, r *Request) {
f(ctx, w, r)
}
type Server struct {
Addr string
Handler Handler
ConnState func(net.Conn, ConnState)
opt option
inShutdown int32
mu sync.Mutex
onShutdown []func() // Concurrent, protected by mu
listeners map[*net.Listener]struct{}
activeConn map[*conn]struct{}
doneChan chan struct{}
}
func ListenAndServe(addr string, handler Handler, opts ...Option) error {
server := &Server{Addr: addr, Handler: handler}
return server.ListenAndServe(opts...)
}
func HandleFunc(pattern string, handler func(context.Context, ResponseWriter, *Request)) {
DefaultServeMux.HandleFunc(pattern, handler)
}
func (srv *Server) ListenAndServe(opts ...Option) error {
if srv.shuttingDown() {
return ErrServerClosed
}
if len(srv.Addr) == 0 {
srv.Addr = ":6379"
}
ln, err := net.Listen("tcp", srv.Addr)
if err != nil {
return err
}
return srv.Serve(ln, opts...)
}
func (srv *Server) Serve(l net.Listener, opts ...Option) error {
defer l.Close()
// Initial
if srv.Handler == nil {
srv.Handler = DefaultServeMux
}
for _, applyOpt := range opts {
applyOpt(&srv.opt)
}
// Trace lister for release
if !srv.trackListener(&l, true) {
return ErrServerClosed
}
defer srv.trackListener(&l, false)
var (
tempDelay time.Duration
ctx = context.WithValue(context.Background(), ServerContextKey, srv)
)
for {
rw, err := l.Accept()
if err != nil {
select {
case <-srv.getDoneChan():
return ErrServerClosed
default:
}
if ne, ok := err.(net.Error); ok && ne.Temporary() {
if tempDelay == 0 {
tempDelay = 5 * time.Millisecond
} else {
tempDelay *= 2
}
if max := 1 * time.Second; tempDelay > max {
tempDelay = max
}
time.Sleep(tempDelay)
continue
}
return err
}
tempDelay = 0
// For close gracefully
c := srv.newConn(rw)
c.setState(c.rwc, StateNew)
// Protocol resolution and routing addressing
go func() {
errReply := "-connection limit over\r\n"
defer func() {
if err := recover(); err != nil {
if srv.opt.PanicStack != nil {
srv.opt.PanicStack(string(debug.Stack()))
}
errReply = "-internal failed\r\n"
}
c.rwc.Write([]byte(errReply))
c.setState(c.rwc, StateClosed)
c.rwc.Close()
}()
sema := srv.opt.Sema
if !sema.opt.Block {
ok := sema.sema.TryAcquire(1)
if !ok {
return
}
} else {
waitCtx, waitCanc := context.WithTimeout(ctx, sema.opt.Wait)
defer waitCanc()
err = sema.sema.Acquire(waitCtx, 1)
if err != nil {
return
}
}
defer sema.sema.Release(1)
c.serve(ctx)
}()
}
}
func NotFound(ctx context.Context, w ResponseWriter, r *Request) { w.Error("Unsupport cmd") }
func NotFoundHandler() Handler { return HandlerFunc(NotFound) }