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|
package rudp
import (
"net"
"sync"
"sync/atomic"
"time"
)
// A Conn is a connection to a client or server.
// All Conn's methods are safe for concurrent use.
type Conn struct {
udpConn udpConn
id PeerID
pkts chan Pkt
errs chan error
timeout *time.Timer
ping *time.Ticker
closing uint32
closed chan struct{}
err error
mu sync.RWMutex
remoteID PeerID
chans [ChannelCount]pktChan // read/write
}
// ID returns the PeerID of the Conn.
func (c *Conn) ID() PeerID { return c.id }
// IsSrv reports whether the Conn is a connection to a server.
func (c *Conn) IsSrv() bool { return c.ID() == PeerIDSrv }
// Closed returns a channel which is closed when the Conn is closed.
func (c *Conn) Closed() <-chan struct{} { return c.closed }
// WhyClosed returns the error that caused the Conn to be closed or nil
// if the Conn was closed using the Close method or by the peer.
// WhyClosed returns nil if the Conn is not closed.
func (c *Conn) WhyClosed() error {
select {
case <-c.Closed():
return c.err
default:
return nil
}
}
// LocalAddr returns the local network address.
func (c *Conn) LocalAddr() net.Addr { return c.udpConn.LocalAddr() }
// RemoteAddr returns the remote network address.
func (c *Conn) RemoteAddr() net.Addr { return c.udpConn.RemoteAddr() }
type pktChan struct {
// Only accessed by Conn.recvUDPPkts goroutine.
inRels *[0x8000][]byte
inRelSN seqnum
sendAck func() (<-chan struct{}, error)
ackBuf []byte
inSplitsMu sync.RWMutex
inSplits map[seqnum]*inSplit
ackChans sync.Map // map[seqnum]chan struct{}
outSplitMu sync.Mutex
outSplitSN seqnum
outRelMu sync.Mutex
outRelSN seqnum
outRelWin seqnum
}
type inSplit struct {
chunks [][]byte
got int
timeout *time.Timer
}
// Close closes the Conn.
// Any blocked Send or Recv calls will return net.ErrClosed.
func (c *Conn) Close() error {
return c.closeDisco(nil)
}
func (c *Conn) closeDisco(err error) error {
c.sendRaw(func(buf []byte) int {
buf[0] = uint8(rawCtl)
buf[1] = uint8(ctlDisco)
return 2
}, PktInfo{Unrel: true})()
return c.close(err)
}
func (c *Conn) close(err error) error {
if atomic.SwapUint32(&c.closing, 1) == 1 {
return net.ErrClosed
}
c.timeout.Stop()
c.ping.Stop()
c.err = err
defer close(c.closed)
return c.udpConn.Close()
}
func newConn(uc udpConn, id, remoteID PeerID) *Conn {
var c *Conn
c = &Conn{
udpConn: uc,
id: id,
pkts: make(chan Pkt),
errs: make(chan error),
timeout: time.AfterFunc(ConnTimeout, func() {
c.closeDisco(ErrTimedOut)
}),
ping: time.NewTicker(PingTimeout),
closed: make(chan struct{}),
remoteID: remoteID,
}
for i := range c.chans {
c.chans[i] = pktChan{
inRels: new([0x8000][]byte),
inRelSN: initSeqnum,
inSplits: make(map[seqnum]*inSplit),
outSplitSN: initSeqnum,
outRelSN: initSeqnum,
outRelWin: initSeqnum,
}
}
c.newAckBuf()
go c.recvUDPPkts()
if remoteID != PeerIDNil {
go c.sendPings(c.ping.C)
}
return c
}
func (c *Conn) sendPings(ping <-chan time.Time) {
send := c.sendRaw(func(buf []byte) int {
buf[0] = uint8(rawCtl)
buf[1] = uint8(ctlPing)
return 2
}, PktInfo{})
for {
select {
case <-ping:
send()
case <-c.Closed():
return
}
}
}
|
