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package conn
import (
"bufio"
"errors"
"fmt"
"io"
"math"
"net"
"reflect"
"runtime/debug"
"sync"
"sync/atomic"
"time"
"github.com/gogo/protobuf/proto"
flow "github.com/tendermint/tendermint/libs/flowrate"
"github.com/tendermint/tendermint/libs/log"
tmmath "github.com/tendermint/tendermint/libs/math"
"github.com/tendermint/tendermint/libs/protoio"
"github.com/tendermint/tendermint/libs/service"
"github.com/tendermint/tendermint/libs/timer"
tmp2p "github.com/tendermint/tendermint/proto/tendermint/p2p"
)
const (
defaultMaxPacketMsgPayloadSize = 1024
numBatchPacketMsgs = 10
minReadBufferSize = 1024
minWriteBufferSize = 65536
updateStats = 2 * time.Second
// some of these defaults are written in the user config
// flushThrottle, sendRate, recvRate
// TODO: remove values present in config
defaultFlushThrottle = 100 * time.Millisecond
defaultSendQueueCapacity = 1
defaultRecvBufferCapacity = 4096
defaultRecvMessageCapacity = 22020096 // 21MB
defaultSendRate = int64(512000) // 500KB/s
defaultRecvRate = int64(512000) // 500KB/s
defaultSendTimeout = 10 * time.Second
defaultPingInterval = 60 * time.Second
defaultPongTimeout = 45 * time.Second
)
type receiveCbFunc func(chID byte, msgBytes []byte)
type errorCbFunc func(interface{})
/*
Each peer has one `MConnection` (multiplex connection) instance.
__multiplex__ *noun* a system or signal involving simultaneous transmission of
several messages along a single channel of communication.
Each `MConnection` handles message transmission on multiple abstract communication
`Channel`s. Each channel has a globally unique byte id.
The byte id and the relative priorities of each `Channel` are configured upon
initialization of the connection.
There are two methods for sending messages:
func (m MConnection) Send(chID byte, msgBytes []byte) bool {}
func (m MConnection) TrySend(chID byte, msgBytes []byte}) bool {}
`Send(chID, msgBytes)` is a blocking call that waits until `msg` is
successfully queued for the channel with the given id byte `chID`, or until the
request times out. The message `msg` is serialized using Protobuf.
`TrySend(chID, msgBytes)` is a nonblocking call that returns false if the
channel's queue is full.
Inbound message bytes are handled with an onReceive callback function.
*/
type MConnection struct {
service.BaseService
conn net.Conn
bufConnReader *bufio.Reader
bufConnWriter *bufio.Writer
sendMonitor *flow.Monitor
recvMonitor *flow.Monitor
send chan struct{}
pong chan struct{}
channels []*Channel
channelsIdx map[byte]*Channel
onReceive receiveCbFunc
onError errorCbFunc
errored uint32
config MConnConfig
// Closing quitSendRoutine will cause the sendRoutine to eventually quit.
// doneSendRoutine is closed when the sendRoutine actually quits.
quitSendRoutine chan struct{}
doneSendRoutine chan struct{}
// Closing quitRecvRouting will cause the recvRouting to eventually quit.
quitRecvRoutine chan struct{}
// used to ensure FlushStop and OnStop
// are safe to call concurrently.
stopMtx sync.Mutex
flushTimer *timer.ThrottleTimer // flush writes as necessary but throttled.
pingTimer *time.Ticker // send pings periodically
// close conn if pong is not received in pongTimeout
pongTimer *time.Timer
pongTimeoutCh chan bool // true - timeout, false - peer sent pong
chStatsTimer *time.Ticker // update channel stats periodically
created time.Time // time of creation
_maxPacketMsgSize int
}
// MConnConfig is a MConnection configuration.
type MConnConfig struct {
SendRate int64 `mapstructure:"send_rate"`
RecvRate int64 `mapstructure:"recv_rate"`
// Maximum payload size
MaxPacketMsgPayloadSize int `mapstructure:"max_packet_msg_payload_size"`
// Interval to flush writes (throttled)
FlushThrottle time.Duration `mapstructure:"flush_throttle"`
// Interval to send pings
PingInterval time.Duration `mapstructure:"ping_interval"`
// Maximum wait time for pongs
PongTimeout time.Duration `mapstructure:"pong_timeout"`
}
// DefaultMConnConfig returns the default config.
func DefaultMConnConfig() MConnConfig {
return MConnConfig{
SendRate: defaultSendRate,
RecvRate: defaultRecvRate,
MaxPacketMsgPayloadSize: defaultMaxPacketMsgPayloadSize,
FlushThrottle: defaultFlushThrottle,
PingInterval: defaultPingInterval,
PongTimeout: defaultPongTimeout,
}
}
// NewMConnection wraps net.Conn and creates multiplex connection
func NewMConnection(
conn net.Conn,
chDescs []*ChannelDescriptor,
onReceive receiveCbFunc,
onError errorCbFunc,
) *MConnection {
return NewMConnectionWithConfig(
conn,
chDescs,
onReceive,
onError,
DefaultMConnConfig())
}
// NewMConnectionWithConfig wraps net.Conn and creates multiplex connection with a config
func NewMConnectionWithConfig(
conn net.Conn,
chDescs []*ChannelDescriptor,
onReceive receiveCbFunc,
onError errorCbFunc,
config MConnConfig,
) *MConnection {
if config.PongTimeout >= config.PingInterval {
panic("pongTimeout must be less than pingInterval (otherwise, next ping will reset pong timer)")
}
mconn := &MConnection{
conn: conn,
bufConnReader: bufio.NewReaderSize(conn, minReadBufferSize),
bufConnWriter: bufio.NewWriterSize(conn, minWriteBufferSize),
sendMonitor: flow.New(0, 0),
recvMonitor: flow.New(0, 0),
send: make(chan struct{}, 1),
pong: make(chan struct{}, 1),
onReceive: onReceive,
onError: onError,
config: config,
created: time.Now(),
}
// Create channels
var channelsIdx = map[byte]*Channel{}
var channels = []*Channel{}
for _, desc := range chDescs {
channel := newChannel(mconn, *desc)
channelsIdx[channel.desc.ID] = channel
channels = append(channels, channel)
}
mconn.channels = channels
mconn.channelsIdx = channelsIdx
mconn.BaseService = *service.NewBaseService(nil, "MConnection", mconn)
// maxPacketMsgSize() is a bit heavy, so call just once
mconn._maxPacketMsgSize = mconn.maxPacketMsgSize()
return mconn
}
func (c *MConnection) SetLogger(l log.Logger) {
c.BaseService.SetLogger(l)
for _, ch := range c.channels {
ch.SetLogger(l)
}
}
// OnStart implements BaseService
func (c *MConnection) OnStart() error {
if err := c.BaseService.OnStart(); err != nil {
return err
}
c.flushTimer = timer.NewThrottleTimer("flush", c.config.FlushThrottle)
c.pingTimer = time.NewTicker(c.config.PingInterval)
c.pongTimeoutCh = make(chan bool, 1)
c.chStatsTimer = time.NewTicker(updateStats)
c.quitSendRoutine = make(chan struct{})
c.doneSendRoutine = make(chan struct{})
c.quitRecvRoutine = make(chan struct{})
go c.sendRoutine()
go c.recvRoutine()
return nil
}
// stopServices stops the BaseService and timers and closes the quitSendRoutine.
// if the quitSendRoutine was already closed, it returns true, otherwise it returns false.
// It uses the stopMtx to ensure only one of FlushStop and OnStop can do this at a time.
func (c *MConnection) stopServices() (alreadyStopped bool) {
c.stopMtx.Lock()
defer c.stopMtx.Unlock()
select {
case <-c.quitSendRoutine:
// already quit
return true
default:
}
select {
case <-c.quitRecvRoutine:
// already quit
return true
default:
}
c.BaseService.OnStop()
c.flushTimer.Stop()
c.pingTimer.Stop()
c.chStatsTimer.Stop()
// inform the recvRouting that we are shutting down
close(c.quitRecvRoutine)
close(c.quitSendRoutine)
return false
}
// FlushStop replicates the logic of OnStop.
// It additionally ensures that all successful
// .Send() calls will get flushed before closing
// the connection.
func (c *MConnection) FlushStop() {
if c.stopServices() {
return
}
// this block is unique to FlushStop
{
// wait until the sendRoutine exits
// so we dont race on calling sendSomePacketMsgs
<-c.doneSendRoutine
// Send and flush all pending msgs.
// Since sendRoutine has exited, we can call this
// safely
eof := c.sendSomePacketMsgs()
for !eof {
eof = c.sendSomePacketMsgs()
}
c.flush()
// Now we can close the connection
}
c.conn.Close() // nolint: errcheck
// We can't close pong safely here because
// recvRoutine may write to it after we've stopped.
// Though it doesn't need to get closed at all,
// we close it @ recvRoutine.
// c.Stop()
}
// OnStop implements BaseService
func (c *MConnection) OnStop() {
if c.stopServices() {
return
}
c.conn.Close() // nolint: errcheck
// We can't close pong safely here because
// recvRoutine may write to it after we've stopped.
// Though it doesn't need to get closed at all,
// we close it @ recvRoutine.
}
func (c *MConnection) String() string {
return fmt.Sprintf("MConn{%v}", c.conn.RemoteAddr())
}
func (c *MConnection) flush() {
c.Logger.Debug("Flush", "conn", c)
err := c.bufConnWriter.Flush()
if err != nil {
c.Logger.Error("MConnection flush failed", "err", err)
}
}
// Catch panics, usually caused by remote disconnects.
func (c *MConnection) _recover() {
if r := recover(); r != nil {
c.Logger.Error("MConnection panicked", "err", r, "stack", string(debug.Stack()))
c.stopForError(fmt.Errorf("recovered from panic: %v", r))
}
}
func (c *MConnection) stopForError(r interface{}) {
c.Stop()
if atomic.CompareAndSwapUint32(&c.errored, 0, 1) {
if c.onError != nil {
c.onError(r)
}
}
}
// Queues a message to be sent to channel.
func (c *MConnection) Send(chID byte, msgBytes []byte) bool {
if !c.IsRunning() {
return false
}
c.Logger.Debug("Send", "channel", chID, "conn", c, "msgBytes", fmt.Sprintf("%X", msgBytes))
// Send message to channel.
channel, ok := c.channelsIdx[chID]
if !ok {
c.Logger.Error(fmt.Sprintf("Cannot send bytes, unknown channel %X", chID))
return false
}
success := channel.sendBytes(msgBytes)
if success {
// Wake up sendRoutine if necessary
select {
case c.send <- struct{}{}:
default:
}
} else {
c.Logger.Debug("Send failed", "channel", chID, "conn", c, "msgBytes", fmt.Sprintf("%X", msgBytes))
}
return success
}
// Queues a message to be sent to channel.
// Nonblocking, returns true if successful.
func (c *MConnection) TrySend(chID byte, msgBytes []byte) bool {
if !c.IsRunning() {
return false
}
c.Logger.Debug("TrySend", "channel", chID, "conn", c, "msgBytes", fmt.Sprintf("%X", msgBytes))
// Send message to channel.
channel, ok := c.channelsIdx[chID]
if !ok {
c.Logger.Error(fmt.Sprintf("Cannot send bytes, unknown channel %X", chID))
return false
}
ok = channel.trySendBytes(msgBytes)
if ok {
// Wake up sendRoutine if necessary
select {
case c.send <- struct{}{}:
default:
}
}
return ok
}
// CanSend returns true if you can send more data onto the chID, false
// otherwise. Use only as a heuristic.
func (c *MConnection) CanSend(chID byte) bool {
if !c.IsRunning() {
return false
}
channel, ok := c.channelsIdx[chID]
if !ok {
c.Logger.Error(fmt.Sprintf("Unknown channel %X", chID))
return false
}
return channel.canSend()
}
// sendRoutine polls for packets to send from channels.
func (c *MConnection) sendRoutine() {
defer c._recover()
protoWriter := protoio.NewDelimitedWriter(c.bufConnWriter)
FOR_LOOP:
for {
var _n int
var err error
SELECTION:
select {
case <-c.flushTimer.Ch:
// NOTE: flushTimer.Set() must be called every time
// something is written to .bufConnWriter.
c.flush()
case <-c.chStatsTimer.C:
for _, channel := range c.channels {
channel.updateStats()
}
case <-c.pingTimer.C:
c.Logger.Debug("Send Ping")
_n, err = protoWriter.WriteMsg(mustWrapPacket(&tmp2p.PacketPing{}))
if err != nil {
c.Logger.Error("Failed to send PacketPing", "err", err)
break SELECTION
}
c.sendMonitor.Update(_n)
c.Logger.Debug("Starting pong timer", "dur", c.config.PongTimeout)
c.pongTimer = time.AfterFunc(c.config.PongTimeout, func() {
select {
case c.pongTimeoutCh <- true:
default:
}
})
c.flush()
case timeout := <-c.pongTimeoutCh:
if timeout {
c.Logger.Debug("Pong timeout")
err = errors.New("pong timeout")
} else {
c.stopPongTimer()
}
case <-c.pong:
c.Logger.Debug("Send Pong")
_n, err = protoWriter.WriteMsg(mustWrapPacket(&tmp2p.PacketPong{}))
if err != nil {
c.Logger.Error("Failed to send PacketPong", "err", err)
break SELECTION
}
c.sendMonitor.Update(_n)
c.flush()
case <-c.quitSendRoutine:
break FOR_LOOP
case <-c.send:
// Send some PacketMsgs
eof := c.sendSomePacketMsgs()
if !eof {
// Keep sendRoutine awake.
select {
case c.send <- struct{}{}:
default:
}
}
}
if !c.IsRunning() {
break FOR_LOOP
}
if err != nil {
c.Logger.Error("Connection failed @ sendRoutine", "conn", c, "err", err)
c.stopForError(err)
break FOR_LOOP
}
}
// Cleanup
c.stopPongTimer()
close(c.doneSendRoutine)
}
// Returns true if messages from channels were exhausted.
// Blocks in accordance to .sendMonitor throttling.
func (c *MConnection) sendSomePacketMsgs() bool {
// Block until .sendMonitor says we can write.
// Once we're ready we send more than we asked for,
// but amortized it should even out.
c.sendMonitor.Limit(c._maxPacketMsgSize, atomic.LoadInt64(&c.config.SendRate), true)
// Now send some PacketMsgs.
for i := 0; i < numBatchPacketMsgs; i++ {
if c.sendPacketMsg() {
return true
}
}
return false
}
// Returns true if messages from channels were exhausted.
func (c *MConnection) sendPacketMsg() bool {
// Choose a channel to create a PacketMsg from.
// The chosen channel will be the one whose recentlySent/priority is the least.
var leastRatio float32 = math.MaxFloat32
var leastChannel *Channel
for _, channel := range c.channels {
// If nothing to send, skip this channel
if !channel.isSendPending() {
continue
}
// Get ratio, and keep track of lowest ratio.
ratio := float32(channel.recentlySent) / float32(channel.desc.Priority)
if ratio < leastRatio {
leastRatio = ratio
leastChannel = channel
}
}
// Nothing to send?
if leastChannel == nil {
return true
}
// c.Logger.Info("Found a msgPacket to send")
// Make & send a PacketMsg from this channel
_n, err := leastChannel.writePacketMsgTo(c.bufConnWriter)
if err != nil {
c.Logger.Error("Failed to write PacketMsg", "err", err)
c.stopForError(err)
return true
}
c.sendMonitor.Update(_n)
c.flushTimer.Set()
return false
}
// recvRoutine reads PacketMsgs and reconstructs the message using the channels' "recving" buffer.
// After a whole message has been assembled, it's pushed to onReceive().
// Blocks depending on how the connection is throttled.
// Otherwise, it never blocks.
func (c *MConnection) recvRoutine() {
defer c._recover()
protoReader := protoio.NewDelimitedReader(c.bufConnReader, c._maxPacketMsgSize)
FOR_LOOP:
for {
// Block until .recvMonitor says we can read.
c.recvMonitor.Limit(c._maxPacketMsgSize, atomic.LoadInt64(&c.config.RecvRate), true)
// Peek into bufConnReader for debugging
/*
if numBytes := c.bufConnReader.Buffered(); numBytes > 0 {
bz, err := c.bufConnReader.Peek(tmmath.MinInt(numBytes, 100))
if err == nil {
// return
} else {
c.Logger.Debug("Error peeking connection buffer", "err", err)
// return nil
}
c.Logger.Info("Peek connection buffer", "numBytes", numBytes, "bz", bz)
}
*/
// Read packet type
var packet tmp2p.Packet
err := protoReader.ReadMsg(&packet)
if err != nil {
// stopServices was invoked and we are shutting down
// receiving is excpected to fail since we will close the connection
select {
case <-c.quitRecvRoutine:
break FOR_LOOP
default:
}
if c.IsRunning() {
if err == io.EOF {
c.Logger.Info("Connection is closed @ recvRoutine (likely by the other side)", "conn", c)
} else {
c.Logger.Error("Connection failed @ recvRoutine (reading byte)", "conn", c, "err", err)
}
c.stopForError(err)
}
break FOR_LOOP
}
// Read more depending on packet type.
switch pkt := packet.Sum.(type) {
case *tmp2p.Packet_PacketPing:
// TODO: prevent abuse, as they cause flush()'s.
// https://github.com/tendermint/tendermint/issues/1190
c.Logger.Debug("Receive Ping")
select {
case c.pong <- struct{}{}:
default:
// never block
}
case *tmp2p.Packet_PacketPong:
c.Logger.Debug("Receive Pong")
select {
case c.pongTimeoutCh <- false:
default:
// never block
}
case *tmp2p.Packet_PacketMsg:
channel, ok := c.channelsIdx[byte(pkt.PacketMsg.ChannelID)]
if !ok || channel == nil {
err := fmt.Errorf("unknown channel %X", pkt.PacketMsg.ChannelID)
c.Logger.Error("Connection failed @ recvRoutine", "conn", c, "err", err)
c.stopForError(err)
break FOR_LOOP
}
msgBytes, err := channel.recvPacketMsg(*pkt.PacketMsg)
if err != nil {
if c.IsRunning() {
c.Logger.Error("Connection failed @ recvRoutine", "conn", c, "err", err)
c.stopForError(err)
}
break FOR_LOOP
}
if msgBytes != nil {
c.Logger.Debug("Received bytes", "chID", pkt.PacketMsg.ChannelID, "msgBytes", fmt.Sprintf("%X", msgBytes))
// NOTE: This means the reactor.Receive runs in the same thread as the p2p recv routine
c.onReceive(byte(pkt.PacketMsg.ChannelID), msgBytes)
}
default:
err := fmt.Errorf("unknown message type %v", reflect.TypeOf(packet))
c.Logger.Error("Connection failed @ recvRoutine", "conn", c, "err", err)
c.stopForError(err)
break FOR_LOOP
}
}
// Cleanup
close(c.pong)
for range c.pong {
// Drain
}
}
// not goroutine-safe
func (c *MConnection) stopPongTimer() {
if c.pongTimer != nil {
_ = c.pongTimer.Stop()
c.pongTimer = nil
}
}
// maxPacketMsgSize returns a maximum size of PacketMsg
func (c *MConnection) maxPacketMsgSize() int {
bz, err := proto.Marshal(mustWrapPacket(&tmp2p.PacketMsg{
ChannelID: 0x01,
EOF: 1,
Data: make([]byte, c.config.MaxPacketMsgPayloadSize),
}))
if err != nil {
panic(err)
}
return len(bz)
}
type ConnectionStatus struct {
Duration time.Duration
SendMonitor flow.Status
RecvMonitor flow.Status
Channels []ChannelStatus
}
type ChannelStatus struct {
ID byte
SendQueueCapacity int
SendQueueSize int
Priority int
RecentlySent int64
}
func (c *MConnection) Status() ConnectionStatus {
var status ConnectionStatus
status.Duration = time.Since(c.created)
status.SendMonitor = c.sendMonitor.Status()
status.RecvMonitor = c.recvMonitor.Status()
status.Channels = make([]ChannelStatus, len(c.channels))
for i, channel := range c.channels {
status.Channels[i] = ChannelStatus{
ID: channel.desc.ID,
SendQueueCapacity: cap(channel.sendQueue),
SendQueueSize: int(atomic.LoadInt32(&channel.sendQueueSize)),
Priority: channel.desc.Priority,
RecentlySent: atomic.LoadInt64(&channel.recentlySent),
}
}
return status
}
//-----------------------------------------------------------------------------
type ChannelDescriptor struct {
ID byte
Priority int
SendQueueCapacity int
RecvBufferCapacity int
RecvMessageCapacity int
}
func (chDesc ChannelDescriptor) FillDefaults() (filled ChannelDescriptor) {
if chDesc.SendQueueCapacity == 0 {
chDesc.SendQueueCapacity = defaultSendQueueCapacity
}
if chDesc.RecvBufferCapacity == 0 {
chDesc.RecvBufferCapacity = defaultRecvBufferCapacity
}
if chDesc.RecvMessageCapacity == 0 {
chDesc.RecvMessageCapacity = defaultRecvMessageCapacity
}
filled = chDesc
return
}
// TODO: lowercase.
// NOTE: not goroutine-safe.
type Channel struct {
conn *MConnection
desc ChannelDescriptor
sendQueue chan []byte
sendQueueSize int32 // atomic.
recving []byte
sending []byte
recentlySent int64 // exponential moving average
maxPacketMsgPayloadSize int
Logger log.Logger
}
func newChannel(conn *MConnection, desc ChannelDescriptor) *Channel {
desc = desc.FillDefaults()
if desc.Priority <= 0 {
panic("Channel default priority must be a positive integer")
}
return &Channel{
conn: conn,
desc: desc,
sendQueue: make(chan []byte, desc.SendQueueCapacity),
recving: make([]byte, 0, desc.RecvBufferCapacity),
maxPacketMsgPayloadSize: conn.config.MaxPacketMsgPayloadSize,
}
}
func (ch *Channel) SetLogger(l log.Logger) {
ch.Logger = l
}
// Queues message to send to this channel.
// Goroutine-safe
// Times out (and returns false) after defaultSendTimeout
func (ch *Channel) sendBytes(bytes []byte) bool {
select {
case ch.sendQueue <- bytes:
atomic.AddInt32(&ch.sendQueueSize, 1)
return true
case <-time.After(defaultSendTimeout):
return false
}
}
// Queues message to send to this channel.
// Nonblocking, returns true if successful.
// Goroutine-safe
func (ch *Channel) trySendBytes(bytes []byte) bool {
select {
case ch.sendQueue <- bytes:
atomic.AddInt32(&ch.sendQueueSize, 1)
return true
default:
return false
}
}
// Goroutine-safe
func (ch *Channel) loadSendQueueSize() (size int) {
return int(atomic.LoadInt32(&ch.sendQueueSize))
}
// Goroutine-safe
// Use only as a heuristic.
func (ch *Channel) canSend() bool {
return ch.loadSendQueueSize() < defaultSendQueueCapacity
}
// Returns true if any PacketMsgs are pending to be sent.
// Call before calling nextPacketMsg()
// Goroutine-safe
func (ch *Channel) isSendPending() bool {
if len(ch.sending) == 0 {
if len(ch.sendQueue) == 0 {
return false
}
ch.sending = <-ch.sendQueue
}
return true
}
// Creates a new PacketMsg to send.
// Not goroutine-safe
func (ch *Channel) nextPacketMsg() tmp2p.PacketMsg {
packet := tmp2p.PacketMsg{ChannelID: int32(ch.desc.ID)}
maxSize := ch.maxPacketMsgPayloadSize
packet.Data = ch.sending[:tmmath.MinInt(maxSize, len(ch.sending))]
if len(ch.sending) <= maxSize {
packet.EOF = 0x01
ch.sending = nil
atomic.AddInt32(&ch.sendQueueSize, -1) // decrement sendQueueSize
} else {
packet.EOF = 0x00
ch.sending = ch.sending[tmmath.MinInt(maxSize, len(ch.sending)):]
}
return packet
}
// Writes next PacketMsg to w and updates c.recentlySent.
// Not goroutine-safe
func (ch *Channel) writePacketMsgTo(w io.Writer) (n int, err error) {
packet := ch.nextPacketMsg()
n, err = protoio.NewDelimitedWriter(w).WriteMsg(mustWrapPacket(&packet))
atomic.AddInt64(&ch.recentlySent, int64(n))
return
}
// Handles incoming PacketMsgs. It returns a message bytes if message is
// complete. NOTE message bytes may change on next call to recvPacketMsg.
// Not goroutine-safe
func (ch *Channel) recvPacketMsg(packet tmp2p.PacketMsg) ([]byte, error) {
ch.Logger.Debug("Read PacketMsg", "conn", ch.conn, "packet", packet)
var recvCap, recvReceived = ch.desc.RecvMessageCapacity, len(ch.recving) + len(packet.Data)
if recvCap < recvReceived {
return nil, fmt.Errorf("received message exceeds available capacity: %v < %v", recvCap, recvReceived)
}
ch.recving = append(ch.recving, packet.Data...)
if packet.EOF == 0x01 {
msgBytes := ch.recving
// clear the slice without re-allocating.
// http://stackoverflow.com/questions/16971741/how-do-you-clear-a-slice-in-go
// suggests this could be a memory leak, but we might as well keep the memory for the channel until it closes,
// at which point the recving slice stops being used and should be garbage collected
ch.recving = ch.recving[:0] // make([]byte, 0, ch.desc.RecvBufferCapacity)
return msgBytes, nil
}
return nil, nil
}
// Call this periodically to update stats for throttling purposes.
// Not goroutine-safe
func (ch *Channel) updateStats() {
// Exponential decay of stats.
// TODO: optimize.
atomic.StoreInt64(&ch.recentlySent, int64(float64(atomic.LoadInt64(&ch.recentlySent))*0.8))
}
//----------------------------------------
// Packet
// mustWrapPacket takes a packet kind (oneof) and wraps it in a tmp2p.Packet message.
func mustWrapPacket(pb proto.Message) *tmp2p.Packet {
var msg tmp2p.Packet
switch pb := pb.(type) {
case *tmp2p.Packet: // already a packet
msg = *pb
case *tmp2p.PacketPing:
msg = tmp2p.Packet{
Sum: &tmp2p.Packet_PacketPing{
PacketPing: pb,
},
}
case *tmp2p.PacketPong:
msg = tmp2p.Packet{
Sum: &tmp2p.Packet_PacketPong{
PacketPong: pb,
},
}
case *tmp2p.PacketMsg:
msg = tmp2p.Packet{
Sum: &tmp2p.Packet_PacketMsg{
PacketMsg: pb,
},
}
default:
panic(fmt.Errorf("unknown packet type %T", pb))
}
return &msg
}