forked from smallnest/rpcx
/
stream.go
177 lines (145 loc) ยท 3.83 KB
/
stream.go
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package server
import (
"context"
"crypto/rand"
"errors"
"io"
"net"
"sync"
"time"
lru "github.com/hashicorp/golang-lru"
"github.com/kudoochui/rpcx/log"
"github.com/kudoochui/rpcx/share"
)
var ErrNotAccept = errors.New("server refused the connection")
// StreamHandler handles a streaming connection with client.
type StreamHandler func(conn net.Conn, args *share.StreamServiceArgs)
// StreamAcceptor accepts connection from clients or not.
// You can use it to validate clients and determine if accept or drop the connection.
type StreamAcceptor func(ctx context.Context, args *share.StreamServiceArgs) bool
type streamTokenInfo struct {
token []byte
args *share.StreamServiceArgs
}
// StreamService support streaming between clients and server.
// It registers a streaming service and listens on the given port.
// Clients will invokes this service to get the token and send the token and begin to stream.
type StreamService struct {
Addr string
AdvertiseAddr string
handler StreamHandler
acceptor StreamAcceptor
cachedTokens *lru.Cache
startOnce sync.Once
done chan struct{}
}
// NewStreamService creates a stream service.
func NewStreamService(addr string, streamHandler StreamHandler, acceptor StreamAcceptor, waitNum int) *StreamService {
cachedTokens, _ := lru.New(waitNum)
fi := &StreamService{
Addr: addr,
handler: streamHandler,
cachedTokens: cachedTokens,
}
return fi
}
// EnableFileTransfer supports filetransfer service in this server.
func (s *Server) EnableStreamService(serviceName string, streamService *StreamService) {
if serviceName == "" {
serviceName = share.StreamServiceName
}
_ = streamService.Start()
_ = s.RegisterName(serviceName, streamService, "")
}
func (s *StreamService) Stream(ctx context.Context, args *share.StreamServiceArgs, reply *share.StreamServiceReply) error {
// clientConn := ctx.Value(server.RemoteConnContextKey).(net.Conn)
if s.acceptor != nil && !s.acceptor(ctx, args) {
return ErrNotAccept
}
token := make([]byte, 32)
_, err := rand.Read(token)
if err != nil {
return err
}
*reply = share.StreamServiceReply{
Token: token,
Addr: s.Addr,
}
if s.AdvertiseAddr != "" {
reply.Addr = s.AdvertiseAddr
}
s.cachedTokens.Add(string(token), &streamTokenInfo{token, args})
return nil
}
func (s *StreamService) Start() error {
s.startOnce.Do(func() {
go s.start()
})
return nil
}
func (s *StreamService) start() error {
ln, err := net.Listen("tcp", s.Addr)
if err != nil {
return err
}
var tempDelay time.Duration
for {
select {
case <-s.done:
return nil
default:
conn, e := ln.Accept()
if e != nil {
if ne, ok := e.(net.Error); ok && ne.Temporary() {
if tempDelay == 0 {
tempDelay = 5 * time.Millisecond
} else {
tempDelay *= 2
}
if max := 1 * time.Second; tempDelay > max {
tempDelay = max
}
log.Errorf("filetransfer: accept error: %v; retrying in %v", e, tempDelay)
time.Sleep(tempDelay)
continue
}
return e
}
tempDelay = 0
if tc, ok := conn.(*net.TCPConn); ok {
tc.SetKeepAlive(true)
tc.SetKeepAlivePeriod(3 * time.Minute)
tc.SetLinger(10)
}
token := make([]byte, 32)
_, err := io.ReadFull(conn, token)
if err != nil {
conn.Close()
log.Errorf("failed to read token from %s", conn.RemoteAddr().String())
continue
}
tokenStr := string(token)
info, ok := s.cachedTokens.Get(tokenStr)
if !ok {
conn.Close()
log.Errorf("failed to read token from %s", conn.RemoteAddr().String())
continue
}
s.cachedTokens.Remove(tokenStr)
switch ti := info.(type) {
case *streamTokenInfo:
if s.handler == nil {
conn.Close()
continue
}
go s.handler(conn, ti.args)
default:
conn.Close()
}
}
}
}
func (s *StreamService) Stop() error {
close(s.done)
return nil
}