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5.7 KiB

package p2p
import (
"bufio"
"fmt"
"net"
"sync/atomic"
"time"
. "github.com/tendermint/tendermint/binary"
. "github.com/tendermint/tendermint/common"
)
const (
MinReadBufferSize = 1024
MinWriteBufferSize = 1024
FlushThrottleMS = 50
OutQueueSize = 50
IdleTimeoutMinutes = 5
PingTimeoutMinutes = 2
)
/*
A Connection wraps a network connection and handles buffering and multiplexing.
"Packets" are sent with ".Send(Packet)".
Packets received are sent to channels as commanded by the ".Start(...)" method.
*/
type Connection struct {
ioStats IOStats
sendQueue chan Packet // never closes
conn net.Conn
bufReader *bufio.Reader
bufWriter *bufio.Writer
flushThrottler *Throttler
quit chan struct{}
pingRepeatTimer *RepeatTimer
pong chan struct{}
channels map[string]*Channel
onError func(interface{})
started uint32
stopped uint32
errored uint32
}
var (
PacketTypePing = UInt8(0x00)
PacketTypePong = UInt8(0x01)
PacketTypeMessage = UInt8(0x10)
)
func NewConnection(conn net.Conn) *Connection {
return &Connection{
sendQueue: make(chan Packet, OutQueueSize),
conn: conn,
bufReader: bufio.NewReaderSize(conn, MinReadBufferSize),
bufWriter: bufio.NewWriterSize(conn, MinWriteBufferSize),
flushThrottler: NewThrottler(FlushThrottleMS * time.Millisecond),
quit: make(chan struct{}),
pingRepeatTimer: NewRepeatTimer(PingTimeoutMinutes * time.Minute),
pong: make(chan struct{}),
}
}
// .Start() begins multiplexing packets to and from "channels".
// If an error occurs, the recovered reason is passed to "onError".
func (c *Connection) Start(channels map[string]*Channel, onError func(interface{})) {
log.Debugf("Starting %v", c)
if atomic.CompareAndSwapUint32(&c.started, 0, 1) {
c.channels = channels
c.onError = onError
go c.sendHandler()
go c.recvHandler()
}
}
func (c *Connection) Stop() {
if atomic.CompareAndSwapUint32(&c.stopped, 0, 1) {
log.Debugf("Stopping %v", c)
close(c.quit)
c.conn.Close()
c.flushThrottler.Stop()
c.pingRepeatTimer.Stop()
// We can't close pong safely here because
// recvHandler may write to it after we've stopped.
// Though it doesn't need to get closed at all,
// we close it @ recvHandler.
// close(c.pong)
}
}
func (c *Connection) LocalAddress() *NetAddress {
return NewNetAddress(c.conn.LocalAddr())
}
func (c *Connection) RemoteAddress() *NetAddress {
return NewNetAddress(c.conn.RemoteAddr())
}
// Returns true if successfully queued,
// Returns false if connection was closed.
// Blocks.
func (c *Connection) Send(pkt Packet) bool {
select {
case c.sendQueue <- pkt:
return true
case <-c.quit:
return false
}
}
func (c *Connection) String() string {
return fmt.Sprintf("Connection{%v}", c.conn.RemoteAddr())
}
func (c *Connection) flush() {
// TODO: this is pretty naive.
// We end up flushing when we don't have to (yet).
// A better solution might require us implementing our own buffered writer.
err := c.bufWriter.Flush()
if err != nil {
if atomic.LoadUint32(&c.stopped) != 1 {
log.Warnf("Connection flush failed: %v", err)
}
}
}
// Catch panics, usually caused by remote disconnects.
func (c *Connection) _recover() {
if r := recover(); r != nil {
c.Stop()
if atomic.CompareAndSwapUint32(&c.errored, 0, 1) {
if c.onError != nil {
c.onError(r)
}
}
}
}
// sendHandler pulls from .sendQueue and writes to .bufWriter
func (c *Connection) sendHandler() {
log.Tracef("%v sendHandler", c)
defer c._recover()
FOR_LOOP:
for {
var err error
select {
case sendPkt := <-c.sendQueue:
log.Tracef("Found pkt from sendQueue. Writing pkt to underlying connection")
_, err = PacketTypeMessage.WriteTo(c.bufWriter)
if err != nil {
break
}
_, err = sendPkt.WriteTo(c.bufWriter)
c.flushThrottler.Set()
case <-c.flushThrottler.Ch:
c.flush()
case <-c.pingRepeatTimer.Ch:
_, err = PacketTypePing.WriteTo(c.bufWriter)
c.flush()
case <-c.pong:
_, err = PacketTypePong.WriteTo(c.bufWriter)
c.flush()
case <-c.quit:
break FOR_LOOP
}
if atomic.LoadUint32(&c.stopped) == 1 {
break FOR_LOOP
}
if err != nil {
log.Infof("%v failed @ sendHandler:\n%v", c, err)
c.Stop()
break FOR_LOOP
}
}
log.Tracef("%v sendHandler done", c)
// cleanup
}
// recvHandler reads from .bufReader and pushes to the appropriate
// channel's recvQueue.
func (c *Connection) recvHandler() {
log.Tracef("%v recvHandler", c)
defer c._recover()
FOR_LOOP:
for {
pktType, err := ReadUInt8Safe(c.bufReader)
if err != nil {
if atomic.LoadUint32(&c.stopped) != 1 {
log.Infof("%v failed @ recvHandler", c)
c.Stop()
}
break FOR_LOOP
} else {
log.Tracef("Found pktType %v", pktType)
}
switch pktType {
case PacketTypePing:
// TODO: keep track of these, make sure it isn't abused
// as they cause flush()'s in the send buffer.
c.pong <- struct{}{}
case PacketTypePong:
// do nothing
case PacketTypeMessage:
pkt, err := ReadPacketSafe(c.bufReader)
if err != nil {
if atomic.LoadUint32(&c.stopped) != 1 {
log.Infof("%v failed @ recvHandler", c)
c.Stop()
}
break FOR_LOOP
}
channel := c.channels[string(pkt.Channel)]
if channel == nil {
Panicf("Unknown channel %v", pkt.Channel)
}
channel.recvQueue <- pkt
default:
Panicf("Unknown message type %v", pktType)
}
c.pingRepeatTimer.Reset()
}
log.Tracef("%v recvHandler done", c)
// cleanup
close(c.pong)
for _ = range c.pong {
// drain
}
}
/* IOStats */
type IOStats struct {
TimeConnected Time
LastSent Time
LastRecv Time
BytesRecv UInt64
BytesSent UInt64
PktsRecv UInt64
PktsSent UInt64
}