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685 lines
18 KiB
685 lines
18 KiB
package p2p
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import (
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"bufio"
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"fmt"
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"io"
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"math"
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"net"
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"runtime/debug"
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"sync/atomic"
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"time"
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cmn "github.com/tendermint/go-common"
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flow "github.com/tendermint/go-flowrate/flowrate"
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wire "github.com/tendermint/go-wire"
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)
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const (
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numBatchMsgPackets = 10
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minReadBufferSize = 1024
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minWriteBufferSize = 65536
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updateState = 2 * time.Second
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pingTimeout = 40 * time.Second
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flushThrottle = 100 * time.Millisecond
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defaultSendQueueCapacity = 1
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defaultSendRate = int64(512000) // 500KB/s
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defaultRecvBufferCapacity = 4096
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defaultRecvMessageCapacity = 22020096 // 21MB
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defaultRecvRate = int64(512000) // 500KB/s
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defaultSendTimeout = 10 * time.Second
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)
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type receiveCbFunc func(chID byte, msgBytes []byte)
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type errorCbFunc func(interface{})
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/*
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Each peer has one `MConnection` (multiplex connection) instance.
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__multiplex__ *noun* a system or signal involving simultaneous transmission of
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several messages along a single channel of communication.
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Each `MConnection` handles message transmission on multiple abstract communication
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`Channel`s. Each channel has a globally unique byte id.
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The byte id and the relative priorities of each `Channel` are configured upon
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initialization of the connection.
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There are two methods for sending messages:
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func (m MConnection) Send(chID byte, msg interface{}) bool {}
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func (m MConnection) TrySend(chID byte, msg interface{}) bool {}
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`Send(chID, msg)` is a blocking call that waits until `msg` is successfully queued
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for the channel with the given id byte `chID`, or until the request times out.
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The message `msg` is serialized using the `tendermint/wire` submodule's
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`WriteBinary()` reflection routine.
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`TrySend(chID, msg)` is a nonblocking call that returns false if the channel's
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queue is full.
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Inbound message bytes are handled with an onReceive callback function.
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*/
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type MConnection struct {
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cmn.BaseService
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conn net.Conn
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bufReader *bufio.Reader
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bufWriter *bufio.Writer
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sendMonitor *flow.Monitor
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recvMonitor *flow.Monitor
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send chan struct{}
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pong chan struct{}
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channels []*Channel
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channelsIdx map[byte]*Channel
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onReceive receiveCbFunc
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onError errorCbFunc
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errored uint32
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config *MConnConfig
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quit chan struct{}
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flushTimer *cmn.ThrottleTimer // flush writes as necessary but throttled.
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pingTimer *cmn.RepeatTimer // send pings periodically
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chStatsTimer *cmn.RepeatTimer // update channel stats periodically
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LocalAddress *NetAddress
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RemoteAddress *NetAddress
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}
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// MConnConfig is a MConnection configuration
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type MConnConfig struct {
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SendRate int64
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RecvRate int64
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}
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func defaultMConnectionConfig() *MConnConfig {
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return &MConnConfig{
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SendRate: defaultSendRate,
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RecvRate: defaultRecvRate,
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}
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}
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// NewMConnection wraps net.Conn and creates multiplex connection
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func NewMConnection(conn net.Conn, chDescs []*ChannelDescriptor, onReceive receiveCbFunc, onError errorCbFunc) *MConnection {
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return NewMConnectionWithConfig(
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conn,
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chDescs,
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onReceive,
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onError,
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defaultMConnectionConfig())
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}
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// NewMConnectionWithConfig wraps net.Conn and creates multiplex connection with a config
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func NewMConnectionWithConfig(conn net.Conn, chDescs []*ChannelDescriptor, onReceive receiveCbFunc, onError errorCbFunc, config *MConnConfig) *MConnection {
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mconn := &MConnection{
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conn: conn,
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bufReader: bufio.NewReaderSize(conn, minReadBufferSize),
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bufWriter: bufio.NewWriterSize(conn, minWriteBufferSize),
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sendMonitor: flow.New(0, 0),
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recvMonitor: flow.New(0, 0),
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send: make(chan struct{}, 1),
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pong: make(chan struct{}),
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onReceive: onReceive,
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onError: onError,
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config: config,
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LocalAddress: NewNetAddress(conn.LocalAddr()),
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RemoteAddress: NewNetAddress(conn.RemoteAddr()),
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}
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// Create channels
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var channelsIdx = map[byte]*Channel{}
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var channels = []*Channel{}
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for _, desc := range chDescs {
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descCopy := *desc // copy the desc else unsafe access across connections
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channel := newChannel(mconn, &descCopy)
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channelsIdx[channel.id] = channel
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channels = append(channels, channel)
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}
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mconn.channels = channels
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mconn.channelsIdx = channelsIdx
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mconn.BaseService = *cmn.NewBaseService(log, "MConnection", mconn)
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return mconn
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}
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func (c *MConnection) OnStart() error {
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c.BaseService.OnStart()
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c.quit = make(chan struct{})
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c.flushTimer = cmn.NewThrottleTimer("flush", flushThrottle)
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c.pingTimer = cmn.NewRepeatTimer("ping", pingTimeout)
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c.chStatsTimer = cmn.NewRepeatTimer("chStats", updateState)
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go c.sendRoutine()
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go c.recvRoutine()
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return nil
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}
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func (c *MConnection) OnStop() {
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c.BaseService.OnStop()
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c.flushTimer.Stop()
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c.pingTimer.Stop()
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c.chStatsTimer.Stop()
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if c.quit != nil {
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close(c.quit)
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}
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c.conn.Close()
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// We can't close pong safely here because
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// recvRoutine may write to it after we've stopped.
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// Though it doesn't need to get closed at all,
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// we close it @ recvRoutine.
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// close(c.pong)
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}
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func (c *MConnection) String() string {
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return fmt.Sprintf("MConn{%v}", c.conn.RemoteAddr())
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}
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func (c *MConnection) flush() {
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log.Debug("Flush", "conn", c)
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err := c.bufWriter.Flush()
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if err != nil {
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log.Warn("MConnection flush failed", "error", err)
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}
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}
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// Catch panics, usually caused by remote disconnects.
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func (c *MConnection) _recover() {
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if r := recover(); r != nil {
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stack := debug.Stack()
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err := cmn.StackError{r, stack}
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c.stopForError(err)
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}
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}
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func (c *MConnection) stopForError(r interface{}) {
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c.Stop()
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if atomic.CompareAndSwapUint32(&c.errored, 0, 1) {
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if c.onError != nil {
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c.onError(r)
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}
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}
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}
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// Queues a message to be sent to channel.
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func (c *MConnection) Send(chID byte, msg interface{}) bool {
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if !c.IsRunning() {
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return false
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}
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log.Debug("Send", "channel", chID, "conn", c, "msg", msg) //, "bytes", wire.BinaryBytes(msg))
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// Send message to channel.
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channel, ok := c.channelsIdx[chID]
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if !ok {
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log.Error(cmn.Fmt("Cannot send bytes, unknown channel %X", chID))
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return false
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}
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success := channel.sendBytes(wire.BinaryBytes(msg))
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if success {
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// Wake up sendRoutine if necessary
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select {
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case c.send <- struct{}{}:
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default:
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}
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} else {
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log.Warn("Send failed", "channel", chID, "conn", c, "msg", msg)
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}
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return success
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}
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// Queues a message to be sent to channel.
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// Nonblocking, returns true if successful.
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func (c *MConnection) TrySend(chID byte, msg interface{}) bool {
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if !c.IsRunning() {
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return false
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}
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log.Debug("TrySend", "channel", chID, "conn", c, "msg", msg)
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// Send message to channel.
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channel, ok := c.channelsIdx[chID]
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if !ok {
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log.Error(cmn.Fmt("Cannot send bytes, unknown channel %X", chID))
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return false
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}
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ok = channel.trySendBytes(wire.BinaryBytes(msg))
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if ok {
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// Wake up sendRoutine if necessary
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select {
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case c.send <- struct{}{}:
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default:
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}
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}
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return ok
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}
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func (c *MConnection) CanSend(chID byte) bool {
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if !c.IsRunning() {
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return false
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}
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channel, ok := c.channelsIdx[chID]
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if !ok {
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log.Error(cmn.Fmt("Unknown channel %X", chID))
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return false
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}
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return channel.canSend()
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}
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// sendRoutine polls for packets to send from channels.
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func (c *MConnection) sendRoutine() {
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defer c._recover()
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FOR_LOOP:
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for {
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var n int
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var err error
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select {
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case <-c.flushTimer.Ch:
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// NOTE: flushTimer.Set() must be called every time
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// something is written to .bufWriter.
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c.flush()
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case <-c.chStatsTimer.Ch:
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for _, channel := range c.channels {
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channel.updateStats()
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}
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case <-c.pingTimer.Ch:
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log.Debug("Send Ping")
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wire.WriteByte(packetTypePing, c.bufWriter, &n, &err)
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c.sendMonitor.Update(int(n))
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c.flush()
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case <-c.pong:
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log.Debug("Send Pong")
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wire.WriteByte(packetTypePong, c.bufWriter, &n, &err)
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c.sendMonitor.Update(int(n))
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c.flush()
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case <-c.quit:
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break FOR_LOOP
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case <-c.send:
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// Send some msgPackets
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eof := c.sendSomeMsgPackets()
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if !eof {
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// Keep sendRoutine awake.
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select {
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case c.send <- struct{}{}:
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default:
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}
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}
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}
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if !c.IsRunning() {
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break FOR_LOOP
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}
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if err != nil {
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log.Warn("Connection failed @ sendRoutine", "conn", c, "error", err)
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c.stopForError(err)
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break FOR_LOOP
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}
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}
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// Cleanup
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}
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// Returns true if messages from channels were exhausted.
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// Blocks in accordance to .sendMonitor throttling.
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func (c *MConnection) sendSomeMsgPackets() bool {
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// Block until .sendMonitor says we can write.
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// Once we're ready we send more than we asked for,
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// but amortized it should even out.
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c.sendMonitor.Limit(maxMsgPacketTotalSize, atomic.LoadInt64(&c.config.SendRate), true)
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// Now send some msgPackets.
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for i := 0; i < numBatchMsgPackets; i++ {
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if c.sendMsgPacket() {
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return true
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}
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}
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return false
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}
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// Returns true if messages from channels were exhausted.
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func (c *MConnection) sendMsgPacket() bool {
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// Choose a channel to create a msgPacket from.
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// The chosen channel will be the one whose recentlySent/priority is the least.
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var leastRatio float32 = math.MaxFloat32
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var leastChannel *Channel
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for _, channel := range c.channels {
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// If nothing to send, skip this channel
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if !channel.isSendPending() {
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continue
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}
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// Get ratio, and keep track of lowest ratio.
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ratio := float32(channel.recentlySent) / float32(channel.priority)
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if ratio < leastRatio {
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leastRatio = ratio
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leastChannel = channel
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}
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}
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// Nothing to send?
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if leastChannel == nil {
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return true
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} else {
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// log.Info("Found a msgPacket to send")
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}
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// Make & send a msgPacket from this channel
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n, err := leastChannel.writeMsgPacketTo(c.bufWriter)
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if err != nil {
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log.Warn("Failed to write msgPacket", "error", err)
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c.stopForError(err)
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return true
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}
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c.sendMonitor.Update(int(n))
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c.flushTimer.Set()
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return false
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}
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// recvRoutine reads msgPackets and reconstructs the message using the channels' "recving" buffer.
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// After a whole message has been assembled, it's pushed to onReceive().
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// Blocks depending on how the connection is throttled.
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func (c *MConnection) recvRoutine() {
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defer c._recover()
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FOR_LOOP:
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for {
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// Block until .recvMonitor says we can read.
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c.recvMonitor.Limit(maxMsgPacketTotalSize, atomic.LoadInt64(&c.config.RecvRate), true)
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/*
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// Peek into bufReader for debugging
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if numBytes := c.bufReader.Buffered(); numBytes > 0 {
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log.Info("Peek connection buffer", "numBytes", numBytes, "bytes", log15.Lazy{func() []byte {
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bytes, err := c.bufReader.Peek(MinInt(numBytes, 100))
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if err == nil {
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return bytes
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} else {
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log.Warn("Error peeking connection buffer", "error", err)
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return nil
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}
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}})
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}
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*/
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// Read packet type
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var n int
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var err error
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pktType := wire.ReadByte(c.bufReader, &n, &err)
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c.recvMonitor.Update(int(n))
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if err != nil {
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if c.IsRunning() {
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log.Warn("Connection failed @ recvRoutine (reading byte)", "conn", c, "error", err)
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c.stopForError(err)
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}
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break FOR_LOOP
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}
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// Read more depending on packet type.
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switch pktType {
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case packetTypePing:
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// TODO: prevent abuse, as they cause flush()'s.
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log.Debug("Receive Ping")
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c.pong <- struct{}{}
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case packetTypePong:
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// do nothing
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log.Debug("Receive Pong")
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case packetTypeMsg:
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pkt, n, err := msgPacket{}, int(0), error(nil)
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wire.ReadBinaryPtr(&pkt, c.bufReader, maxMsgPacketTotalSize, &n, &err)
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c.recvMonitor.Update(int(n))
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if err != nil {
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if c.IsRunning() {
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log.Warn("Connection failed @ recvRoutine", "conn", c, "error", err)
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c.stopForError(err)
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}
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break FOR_LOOP
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}
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channel, ok := c.channelsIdx[pkt.ChannelID]
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if !ok || channel == nil {
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cmn.PanicQ(cmn.Fmt("Unknown channel %X", pkt.ChannelID))
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}
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msgBytes, err := channel.recvMsgPacket(pkt)
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if err != nil {
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if c.IsRunning() {
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log.Warn("Connection failed @ recvRoutine", "conn", c, "error", err)
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c.stopForError(err)
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}
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break FOR_LOOP
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}
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if msgBytes != nil {
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log.Debug("Received bytes", "chID", pkt.ChannelID, "msgBytes", msgBytes)
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c.onReceive(pkt.ChannelID, msgBytes)
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}
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default:
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cmn.PanicSanity(cmn.Fmt("Unknown message type %X", pktType))
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}
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// TODO: shouldn't this go in the sendRoutine?
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// Better to send a ping packet when *we* haven't sent anything for a while.
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c.pingTimer.Reset()
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}
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// Cleanup
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close(c.pong)
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for _ = range c.pong {
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// Drain
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}
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}
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type ConnectionStatus struct {
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SendMonitor flow.Status
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RecvMonitor flow.Status
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Channels []ChannelStatus
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}
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type ChannelStatus struct {
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ID byte
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SendQueueCapacity int
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SendQueueSize int
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Priority int
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RecentlySent int64
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}
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func (c *MConnection) Status() ConnectionStatus {
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var status ConnectionStatus
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status.SendMonitor = c.sendMonitor.Status()
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status.RecvMonitor = c.recvMonitor.Status()
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status.Channels = make([]ChannelStatus, len(c.channels))
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for i, channel := range c.channels {
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status.Channels[i] = ChannelStatus{
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ID: channel.id,
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SendQueueCapacity: cap(channel.sendQueue),
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SendQueueSize: int(channel.sendQueueSize), // TODO use atomic
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Priority: channel.priority,
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RecentlySent: channel.recentlySent,
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}
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}
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return status
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}
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//-----------------------------------------------------------------------------
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type ChannelDescriptor struct {
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ID byte
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Priority int
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SendQueueCapacity int
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RecvBufferCapacity int
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RecvMessageCapacity int
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}
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func (chDesc *ChannelDescriptor) FillDefaults() {
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if chDesc.SendQueueCapacity == 0 {
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chDesc.SendQueueCapacity = defaultSendQueueCapacity
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}
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if chDesc.RecvBufferCapacity == 0 {
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chDesc.RecvBufferCapacity = defaultRecvBufferCapacity
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}
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if chDesc.RecvMessageCapacity == 0 {
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chDesc.RecvMessageCapacity = defaultRecvMessageCapacity
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}
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}
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// TODO: lowercase.
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// NOTE: not goroutine-safe.
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type Channel struct {
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conn *MConnection
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desc *ChannelDescriptor
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id byte
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sendQueue chan []byte
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sendQueueSize int32 // atomic.
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recving []byte
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sending []byte
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priority int
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recentlySent int64 // exponential moving average
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}
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func newChannel(conn *MConnection, desc *ChannelDescriptor) *Channel {
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desc.FillDefaults()
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if desc.Priority <= 0 {
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cmn.PanicSanity("Channel default priority must be a postive integer")
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}
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return &Channel{
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conn: conn,
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desc: desc,
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id: desc.ID,
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sendQueue: make(chan []byte, desc.SendQueueCapacity),
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recving: make([]byte, 0, desc.RecvBufferCapacity),
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priority: desc.Priority,
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}
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}
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// Queues message to send to this channel.
|
|
// Goroutine-safe
|
|
// Times out (and returns false) after defaultSendTimeout
|
|
func (ch *Channel) sendBytes(bytes []byte) bool {
|
|
timeout := time.NewTimer(defaultSendTimeout)
|
|
select {
|
|
case <-timeout.C:
|
|
// timeout
|
|
return false
|
|
case ch.sendQueue <- bytes:
|
|
atomic.AddInt32(&ch.sendQueueSize, 1)
|
|
return true
|
|
}
|
|
}
|
|
|
|
// 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 msgPackets are pending to be sent.
|
|
// Call before calling nextMsgPacket()
|
|
// 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 msgPacket to send.
|
|
// Not goroutine-safe
|
|
func (ch *Channel) nextMsgPacket() msgPacket {
|
|
packet := msgPacket{}
|
|
packet.ChannelID = byte(ch.id)
|
|
packet.Bytes = ch.sending[:cmn.MinInt(maxMsgPacketPayloadSize, len(ch.sending))]
|
|
if len(ch.sending) <= maxMsgPacketPayloadSize {
|
|
packet.EOF = byte(0x01)
|
|
ch.sending = nil
|
|
atomic.AddInt32(&ch.sendQueueSize, -1) // decrement sendQueueSize
|
|
} else {
|
|
packet.EOF = byte(0x00)
|
|
ch.sending = ch.sending[cmn.MinInt(maxMsgPacketPayloadSize, len(ch.sending)):]
|
|
}
|
|
return packet
|
|
}
|
|
|
|
// Writes next msgPacket to w.
|
|
// Not goroutine-safe
|
|
func (ch *Channel) writeMsgPacketTo(w io.Writer) (n int, err error) {
|
|
packet := ch.nextMsgPacket()
|
|
log.Debug("Write Msg Packet", "conn", ch.conn, "packet", packet)
|
|
wire.WriteByte(packetTypeMsg, w, &n, &err)
|
|
wire.WriteBinary(packet, w, &n, &err)
|
|
if err == nil {
|
|
ch.recentlySent += int64(n)
|
|
}
|
|
return
|
|
}
|
|
|
|
// Handles incoming msgPackets. Returns a msg bytes if msg is complete.
|
|
// Not goroutine-safe
|
|
func (ch *Channel) recvMsgPacket(packet msgPacket) ([]byte, error) {
|
|
// log.Debug("Read Msg Packet", "conn", ch.conn, "packet", packet)
|
|
if ch.desc.RecvMessageCapacity < len(ch.recving)+len(packet.Bytes) {
|
|
return nil, wire.ErrBinaryReadOverflow
|
|
}
|
|
ch.recving = append(ch.recving, packet.Bytes...)
|
|
if packet.EOF == byte(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.
|
|
ch.recentlySent = int64(float64(ch.recentlySent) * 0.8)
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
|
|
const (
|
|
maxMsgPacketPayloadSize = 1024
|
|
maxMsgPacketOverheadSize = 10 // It's actually lower but good enough
|
|
maxMsgPacketTotalSize = maxMsgPacketPayloadSize + maxMsgPacketOverheadSize
|
|
packetTypePing = byte(0x01)
|
|
packetTypePong = byte(0x02)
|
|
packetTypeMsg = byte(0x03)
|
|
)
|
|
|
|
// Messages in channels are chopped into smaller msgPackets for multiplexing.
|
|
type msgPacket struct {
|
|
ChannelID byte
|
|
EOF byte // 1 means message ends here.
|
|
Bytes []byte
|
|
}
|
|
|
|
func (p msgPacket) String() string {
|
|
return fmt.Sprintf("MsgPacket{%X:%X T:%X}", p.ChannelID, p.Bytes, p.EOF)
|
|
}
|