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transfer_route_manager.go
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1070 lines (902 loc) · 29.9 KB
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package connect
import (
"context"
"errors"
"fmt"
mathrand "math/rand"
"reflect"
"slices"
"sync"
"time"
// "runtime/debug"
"golang.org/x/exp/maps"
"github.com/golang/glog"
)
// manage multiple routes to a destination, allowing weighted reads and writes to the routes
// this assumes the source is a single client
// routes are expected to have flow control and error detection and rejection
type Route = chan []byte
const TransportMaxPriority = 0
const TransportMinPriority = 100
const TransportMaxWeight = float32(1)
const TransportMinWeight = float32(0)
// each transport must have a unique local id
// This solves an issue where some transports can be implemented with zero state.
// Zero state transports makes it ambiguous whether the transport pointer can be used as a key.
// see https://github.com/golang/go/issues/65878
type Transport interface {
TransportId() Id
// lower priority takes precedence
Priority() int
// the intrinsic weight of the transport, [0, 1]
// if the transport has no preference, use 0
Weight() float32
CanEvalRouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) bool
// returns the fraction of route weight that should be allocated to this transport
// the remaining are the lower priority transports
// call `rematchTransport` to re-evaluate the weights. this is used for a control loop where the weight is adjusted to match the actual distribution
RouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) float32
MatchesSend(destination TransferPath) bool
MatchesReceive(destination TransferPath) bool
// request that p2p and direct connections be re-established that include the source
// connections will be denied for sources that have bad audits
Downgrade(source TransferPath)
}
type MultiRouteWriter interface {
Write(ctx context.Context, transferFrameBytes []byte, timeout time.Duration) error
WriteDetailed(ctx context.Context, transferFrameBytes []byte, timeout time.Duration) (bool, error)
GetActiveRoutes() []Route
GetInactiveRoutes() []Route
}
type MultiRouteReader interface {
Read(ctx context.Context, timeout time.Duration) ([]byte, error)
GetActiveRoutes() []Route
GetInactiveRoutes() []Route
}
type RouteManager struct {
ctx context.Context
clientTag string
mutex sync.Mutex
writerMatchState *MatchState
readerMatchState *MatchState
}
func NewRouteManager(ctx context.Context, clientTag string) *RouteManager {
return &RouteManager{
ctx: ctx,
clientTag: clientTag,
writerMatchState: NewMatchState(ctx, clientTag, true, Transport.MatchesSend),
// `weightedRoutes=false` because unless there is a cpu limit this is not needed
readerMatchState: NewMatchState(ctx, clientTag, false, Transport.MatchesReceive),
}
}
func (self *RouteManager) DowngradeReceiverConnection(source TransferPath) {
self.readerMatchState.Downgrade(source)
}
func (self *RouteManager) OpenMultiRouteWriter(destination TransferPath) MultiRouteWriter {
if !destination.IsDestinationMask() {
panic(fmt.Errorf("Destination required for writer: %s", destination))
}
self.mutex.Lock()
defer self.mutex.Unlock()
return MultiRouteWriter(self.writerMatchState.openMultiRouteSelector(destination))
}
func (self *RouteManager) CloseMultiRouteWriter(w MultiRouteWriter) {
self.mutex.Lock()
defer self.mutex.Unlock()
self.writerMatchState.closeMultiRouteSelector(w.(*MultiRouteSelector))
}
func (self *RouteManager) OpenMultiRouteReader(destination TransferPath) MultiRouteReader {
if !destination.IsDestinationMask() {
panic(fmt.Errorf("Destination required for reader: %s", destination))
}
self.mutex.Lock()
defer self.mutex.Unlock()
return MultiRouteReader(self.readerMatchState.openMultiRouteSelector(destination))
}
func (self *RouteManager) CloseMultiRouteReader(r MultiRouteReader) {
self.mutex.Lock()
defer self.mutex.Unlock()
self.readerMatchState.closeMultiRouteSelector(r.(*MultiRouteSelector))
}
func (self *RouteManager) UpdateTransport(transport Transport, routes []Route) {
self.mutex.Lock()
defer self.mutex.Unlock()
self.writerMatchState.updateTransport(transport, routes)
self.readerMatchState.updateTransport(transport, routes)
}
func (self *RouteManager) RemoveTransport(transport Transport) {
self.UpdateTransport(transport, nil)
}
func (self *RouteManager) getTransportStats(transport Transport) (writerStats *RouteStats, readerStats *RouteStats) {
self.mutex.Lock()
defer self.mutex.Unlock()
writerStats = self.writerMatchState.getTransportStats(transport)
readerStats = self.readerMatchState.getTransportStats(transport)
return
}
type MatchState struct {
ctx context.Context
clientTag string
weightedRoutes bool
matches func(Transport, TransferPath) bool
transportRoutes map[Transport][]Route
// destination -> multi route selectors
destinationMultiRouteSelectors map[TransferPath]map[*MultiRouteSelector]bool
// transport -> destinations
transportMatchedDestinations map[Transport]map[TransferPath]bool
}
// note weighted routes typically are used by the sender not receiver
func NewMatchState(ctx context.Context, clientTag string, weightedRoutes bool, matches func(Transport, TransferPath) bool) *MatchState {
return &MatchState{
ctx: ctx,
clientTag: clientTag,
weightedRoutes: weightedRoutes,
matches: matches,
transportRoutes: map[Transport][]Route{},
destinationMultiRouteSelectors: map[TransferPath]map[*MultiRouteSelector]bool{},
transportMatchedDestinations: map[Transport]map[TransferPath]bool{},
}
}
func (self *MatchState) getTransportStats(transport Transport) *RouteStats {
destinations, ok := self.transportMatchedDestinations[transport]
if !ok {
return nil
}
netStats := NewRouteStats()
for destination, _ := range destinations {
if multiRouteSelectors, ok := self.destinationMultiRouteSelectors[destination]; ok {
for multiRouteSelector, _ := range multiRouteSelectors {
if stats := multiRouteSelector.getTransportStats(transport); stats != nil {
netStats.sendCount += stats.sendCount
netStats.sendByteCount += stats.sendByteCount
netStats.receiveCount += stats.receiveCount
netStats.receiveByteCount += stats.receiveByteCount
}
}
}
}
return netStats
}
func (self *MatchState) openMultiRouteSelector(destination TransferPath) *MultiRouteSelector {
multiRouteSelector := NewMultiRouteSelector(self.ctx, self.clientTag, destination, self.weightedRoutes)
multiRouteSelectors, ok := self.destinationMultiRouteSelectors[destination]
if !ok {
multiRouteSelectors = map[*MultiRouteSelector]bool{}
self.destinationMultiRouteSelectors[destination] = multiRouteSelectors
}
multiRouteSelectors[multiRouteSelector] = true
for transport, routes := range self.transportRoutes {
matchedDestinations, ok := self.transportMatchedDestinations[transport]
if !ok {
matchedDestinations := map[TransferPath]bool{}
self.transportMatchedDestinations[transport] = matchedDestinations
}
// use the latest matches state
if self.matches(transport, destination) {
matchedDestinations[destination] = true
multiRouteSelector.updateTransport(transport, routes)
}
}
return multiRouteSelector
}
func (self *MatchState) closeMultiRouteSelector(multiRouteSelector *MultiRouteSelector) {
// TODO readers do not need to prioritize routes
destination := multiRouteSelector.destination
multiRouteSelectors, ok := self.destinationMultiRouteSelectors[destination]
if !ok {
// not present
return
}
delete(multiRouteSelectors, multiRouteSelector)
if len(multiRouteSelectors) == 0 {
// clean up the destination
for _, matchedDestinations := range self.transportMatchedDestinations {
delete(matchedDestinations, destination)
}
}
}
func (self *MatchState) updateTransport(transport Transport, routes []Route) {
if len(routes) == 0 {
if currentMatchedDestinations, ok := self.transportMatchedDestinations[transport]; ok {
for destination, _ := range currentMatchedDestinations {
if multiRouteSelectors, ok := self.destinationMultiRouteSelectors[destination]; ok {
for multiRouteSelector, _ := range multiRouteSelectors {
multiRouteSelector.updateTransport(transport, nil)
}
}
}
}
delete(self.transportMatchedDestinations, transport)
delete(self.transportRoutes, transport)
} else {
matchedDestinations := map[TransferPath]bool{}
currentMatchedDestinations, ok := self.transportMatchedDestinations[transport]
if !ok {
currentMatchedDestinations = map[TransferPath]bool{}
}
for destination, multiRouteSelectors := range self.destinationMultiRouteSelectors {
if self.matches(transport, destination) {
matchedDestinations[destination] = true
for multiRouteSelector, _ := range multiRouteSelectors {
multiRouteSelector.updateTransport(transport, routes)
}
} else if _, ok := currentMatchedDestinations[destination]; ok {
// no longer matches
for multiRouteSelector, _ := range multiRouteSelectors {
multiRouteSelector.updateTransport(transport, nil)
}
}
}
self.transportMatchedDestinations[transport] = matchedDestinations
self.transportRoutes[transport] = routes
}
}
func (self *MatchState) Downgrade(source TransferPath) {
for transport, _ := range self.transportRoutes {
transport.Downgrade(source)
}
}
type MultiRouteSelector struct {
ctx context.Context
cancel context.CancelFunc
clientTag string
destination TransferPath
weightedRoutes bool
transportUpdate *Monitor
mutex sync.Mutex
transportRoutes map[Transport][]Route
routeStats map[Route]*RouteStats
routeActive map[Route]bool
routeWeight map[Route]float32
}
func NewMultiRouteSelector(ctx context.Context, clientTag string, destination TransferPath, weightedRoutes bool) *MultiRouteSelector {
cancelCtx, cancel := context.WithCancel(ctx)
return &MultiRouteSelector{
ctx: cancelCtx,
cancel: cancel,
clientTag: clientTag,
destination: destination,
weightedRoutes: weightedRoutes,
transportUpdate: NewMonitor(),
transportRoutes: map[Transport][]Route{},
routeStats: map[Route]*RouteStats{},
routeActive: map[Route]bool{},
routeWeight: map[Route]float32{},
}
}
func (self *MultiRouteSelector) getTransportStats(transport Transport) *RouteStats {
self.mutex.Lock()
defer self.mutex.Unlock()
currentRoutes, ok := self.transportRoutes[transport]
if !ok {
return nil
}
netStats := NewRouteStats()
for _, currentRoute := range currentRoutes {
if stats, ok := self.routeStats[currentRoute]; ok {
netStats.sendCount += stats.sendCount
netStats.sendByteCount += stats.sendByteCount
netStats.receiveCount += stats.receiveCount
netStats.receiveByteCount += stats.receiveByteCount
}
}
return netStats
}
// if weightedRoutes, this applies new priorities and weights. calling this resets all route stats.
// the reason to reset weightedRoutes is that the weight calculation needs to consider only the stats since the previous weight change
func (self *MultiRouteSelector) updateTransport(transport Transport, routes []Route) {
self.mutex.Lock()
defer self.mutex.Unlock()
// activeRoutes := func()([]Route) {
// activeRoutes := []Route{}
// for _, routes := range self.transportRoutes {
// for _, route := range routes {
// if self.routeActive[route] {
// activeRoutes = append(activeRoutes, route)
// }
// }
// }
// return activeRoutes
// }
// preTransportCount := len(self.transportRoutes)
// preActiveRouteCount := len(activeRoutes())
if len(routes) == 0 {
if currentRoutes, ok := self.transportRoutes[transport]; ok {
for _, currentRoute := range currentRoutes {
delete(self.routeStats, currentRoute)
delete(self.routeActive, currentRoute)
delete(self.routeWeight, currentRoute)
}
delete(self.transportRoutes, transport)
} else {
// transport is not active. nothing to do
return
}
} else {
if currentRoutes, ok := self.transportRoutes[transport]; ok {
for _, currentRoute := range currentRoutes {
if slices.Index(routes, currentRoute) < 0 {
// no longer present
delete(self.routeStats, currentRoute)
delete(self.routeActive, currentRoute)
delete(self.routeWeight, currentRoute)
}
}
for _, route := range routes {
if slices.Index(currentRoutes, route) < 0 {
// new route
self.routeActive[route] = true
}
}
} else {
for _, route := range routes {
// new route
self.routeActive[route] = true
}
}
// the following will be updated with the new routes in the weighting below
// - routeStats
// - routeActive
// - routeWeights
self.transportRoutes[transport] = routes
}
if self.weightedRoutes {
self.updateRouteWeights()
}
self.transportUpdate.NotifyAll()
}
func (self *MultiRouteSelector) updateRouteWeights() {
updatedRouteWeight := map[Route]float32{}
transportStats := map[Transport]*RouteStats{}
for transport, currentRoutes := range self.transportRoutes {
netStats := NewRouteStats()
for _, currentRoute := range currentRoutes {
if stats, ok := self.routeStats[currentRoute]; ok {
netStats.sendCount += stats.sendCount
netStats.sendByteCount += stats.sendByteCount
netStats.receiveCount += stats.receiveCount
netStats.receiveByteCount += stats.receiveByteCount
}
}
transportStats[transport] = netStats
}
orderedTransports := maps.Keys(self.transportRoutes)
// shuffle the same priority values
mathrand.Shuffle(len(orderedTransports), func(i int, j int) {
t := orderedTransports[i]
orderedTransports[i] = orderedTransports[j]
orderedTransports[j] = t
})
slices.SortStableFunc(orderedTransports, func(a Transport, b Transport) int {
return a.Priority() - b.Priority()
})
n := len(orderedTransports)
allCanEval := true
for i := 0; i < n; i += 1 {
transport := orderedTransports[i]
routeStats := transportStats[transport]
remainingStats := map[Transport]*RouteStats{}
for j := i + 1; j < n; j += 1 {
remainingStats[orderedTransports[j]] = transportStats[orderedTransports[j]]
}
canEval := transport.CanEvalRouteWeight(routeStats, remainingStats)
allCanEval = allCanEval && canEval
}
if allCanEval {
var allWeight float32
allWeight = 1.0
for i := 0; i < n; i += 1 {
transport := orderedTransports[i]
routeStats := transportStats[transport]
remainingStats := map[Transport]*RouteStats{}
for j := i + 1; j < n; j += 1 {
remainingStats[orderedTransports[j]] = transportStats[orderedTransports[j]]
}
weight := transport.RouteWeight(routeStats, remainingStats)
for _, route := range self.transportRoutes[transport] {
updatedRouteWeight[route] = allWeight * weight
}
allWeight *= (1.0 - weight)
}
self.routeWeight = updatedRouteWeight
updatedRouteStats := map[Route]*RouteStats{}
for _, currentRoutes := range self.transportRoutes {
for _, currentRoute := range currentRoutes {
// reset the stats
updatedRouteStats[currentRoute] = NewRouteStats()
}
}
self.routeStats = updatedRouteStats
}
}
func (self *MultiRouteSelector) GetActiveRoutes() []Route {
self.mutex.Lock()
defer self.mutex.Unlock()
activeRoutes := []Route{}
for _, routes := range self.transportRoutes {
for _, route := range routes {
if self.routeActive[route] {
activeRoutes = append(activeRoutes, route)
}
}
}
if self.weightedRoutes {
// prioritize the routes (weighted shuffle)
// if all weights are equal, this is the same as a shuffle
WeightedShuffle(activeRoutes, self.routeWeight)
} else {
mathrand.Shuffle(len(activeRoutes), func(i int, j int) {
activeRoutes[i], activeRoutes[j] = activeRoutes[j], activeRoutes[i]
})
}
return activeRoutes
}
func (self *MultiRouteSelector) GetInactiveRoutes() []Route {
self.mutex.Lock()
defer self.mutex.Unlock()
inactiveRoutes := []Route{}
for _, routes := range self.transportRoutes {
for _, route := range routes {
if !self.routeActive[route] {
inactiveRoutes = append(inactiveRoutes, route)
}
}
}
return inactiveRoutes
}
func (self *MultiRouteSelector) setActive(route Route, active bool) {
self.mutex.Lock()
defer self.mutex.Unlock()
if _, ok := self.routeActive[route]; ok {
self.routeActive[route] = false
}
}
func (self *MultiRouteSelector) updateSendStats(route Route, sendCount int, sendByteCount ByteCount) {
self.mutex.Lock()
defer self.mutex.Unlock()
stats, ok := self.routeStats[route]
if !ok {
stats = NewRouteStats()
self.routeStats[route] = stats
}
stats.sendCount += sendCount
stats.sendByteCount += sendByteCount
}
func (self *MultiRouteSelector) updateReceiveStats(route Route, receiveCount int, receiveByteCount ByteCount) {
self.mutex.Lock()
defer self.mutex.Unlock()
stats, ok := self.routeStats[route]
if !ok {
stats = NewRouteStats()
self.routeStats[route] = stats
}
stats.receiveCount += receiveCount
stats.receiveByteCount += receiveByteCount
}
func (self *MultiRouteSelector) Write(ctx context.Context, transferFrameBytes []byte, timeout time.Duration) error {
success, err := self.WriteDetailed(ctx, transferFrameBytes, timeout)
if err != nil {
return err
}
if !success {
return errors.New("Timeout.")
}
return nil
}
// MultiRouteWriter
func (self *MultiRouteSelector) WriteDetailed(ctx context.Context, transferFrameBytes []byte, timeout time.Duration) (bool, error) {
// write to the first channel available, in random priority
enterTime := time.Now()
for {
notify := self.transportUpdate.NotifyChannel()
activeRoutes := self.GetActiveRoutes()
glog.V(2).Infof("[mrw] %s->%s s(%s) routes = %d\n", self.clientTag, self.destination.DestinationId, self.destination.StreamId, len(activeRoutes))
// non-blocking priority
for _, route := range activeRoutes {
select {
case route <- transferFrameBytes:
glog.V(2).Infof("[mrw]nb %s->%s s(%s)\n", self.clientTag, self.destination.DestinationId, self.destination.StreamId)
self.updateSendStats(route, 1, ByteCount(len(transferFrameBytes)))
return true, nil
default:
}
}
// select cases are in order:
// - ctx.Done
// - self.ctx.Done
// - route writes...
// - transport update
// - timeout (may not exist)
selectCases := make([]reflect.SelectCase, 0, 4+len(activeRoutes))
// add the context done case
contextDoneIndex := len(selectCases)
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(ctx.Done()),
})
// add the done case
doneIndex := len(selectCases)
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(self.ctx.Done()),
})
// add the update case
transportUpdateIndex := len(selectCases)
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(notify),
})
// add all the route
routeStartIndex := len(selectCases)
if 0 < len(activeRoutes) {
sendValue := reflect.ValueOf(transferFrameBytes)
for _, route := range activeRoutes {
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectSend,
Chan: reflect.ValueOf(route),
Send: sendValue,
})
}
}
timeoutIndex := len(selectCases)
if 0 <= timeout {
remainingTimeout := enterTime.Add(timeout).Sub(time.Now())
if remainingTimeout <= 0 {
// add a default case
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectDefault,
})
} else {
// add a timeout case
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(time.After(remainingTimeout)),
})
}
}
chosenIndex, _, _ := reflect.Select(selectCases)
glog.V(2).Infof("[mrw]b %s->%s s(%s)\n", self.clientTag, self.destination.DestinationId, self.destination.SourceId)
switch chosenIndex {
case contextDoneIndex:
return false, errors.New("Context done")
case doneIndex:
return false, errors.New("Done")
case transportUpdateIndex:
// new routes, try again
case timeoutIndex:
return false, nil
default:
// a route
routeIndex := chosenIndex - routeStartIndex
route := activeRoutes[routeIndex]
self.updateSendStats(route, 1, ByteCount(len(transferFrameBytes)))
return true, nil
}
}
}
// MultiRouteReader
func (self *MultiRouteSelector) Read(ctx context.Context, timeout time.Duration) ([]byte, error) {
// read from the first channel available, in random priority
enterTime := time.Now()
for {
notify := self.transportUpdate.NotifyChannel()
activeRoutes := self.GetActiveRoutes()
glog.V(2).Infof("[mrr] %s/%s<- s(%s) routes = %d\n", self.clientTag, self.destination.DestinationId, self.destination.StreamId, len(activeRoutes))
// non-blocking priority
retry := false
for _, route := range activeRoutes {
select {
case transferFrameBytes, ok := <-route:
if ok {
glog.V(2).Infof("[mrr]nb %s/%s<- s(%s)\n", self.clientTag, self.destination.DestinationId, self.destination.StreamId)
self.updateReceiveStats(route, 1, ByteCount(len(transferFrameBytes)))
return transferFrameBytes, nil
} else {
// mark the route as closed, try again
self.setActive(route, false)
retry = true
}
default:
}
}
if retry {
continue
}
// select cases are in order:
// - ctx.Done
// - self.ctx.Done
// - route reads...
// - transport update
// - timeout (may not exist)
selectCases := make([]reflect.SelectCase, 0, 4+len(activeRoutes))
// add the context done case
contextDoneIndex := len(selectCases)
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(self.ctx.Done()),
})
// add the done case
doneIndex := len(selectCases)
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(self.ctx.Done()),
})
// add the update case
transportUpdateIndex := len(selectCases)
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(notify),
})
// add all the route
routeStartIndex := len(selectCases)
if 0 < len(activeRoutes) {
for _, route := range activeRoutes {
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(route),
})
}
}
timeoutIndex := len(selectCases)
if 0 <= timeout {
remainingTimeout := enterTime.Add(timeout).Sub(time.Now())
if remainingTimeout <= 0 {
// add a default case
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectDefault,
})
} else {
// add a timeout case
selectCases = append(selectCases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(time.After(remainingTimeout)),
})
}
}
chosenIndex, value, ok := reflect.Select(selectCases)
glog.V(2).Infof("[mrr]b %s/%s<- s(%s)\n", self.clientTag, self.destination.DestinationId, self.destination.StreamId)
switch chosenIndex {
case contextDoneIndex:
return nil, errors.New("Context done")
case doneIndex:
return nil, errors.New("Done")
case transportUpdateIndex:
// new routes, try again
case timeoutIndex:
// FIXME return nil, nil? don't use errors for timeouts
return nil, nil
default:
// a route
routeIndex := chosenIndex - routeStartIndex
route := activeRoutes[routeIndex]
if ok {
transferFrameBytes := value.Bytes()
self.updateReceiveStats(route, 1, ByteCount(len(transferFrameBytes)))
return transferFrameBytes, nil
} else {
// mark the route as closed, try again
self.setActive(route, false)
}
}
}
}
func (self *MultiRouteSelector) Close() {
self.cancel()
}
type RouteStats struct {
sendCount int
sendByteCount ByteCount
receiveCount int
receiveByteCount ByteCount
}
func NewRouteStats() *RouteStats {
return &RouteStats{
sendCount: 0,
sendByteCount: ByteCount(0),
receiveCount: 0,
receiveByteCount: ByteCount(0),
}
}
// conforms to `Transport`
type sendClientTransport struct {
transportId Id
complement bool
destinations map[TransferPath]bool
}
func NewSendClientTransport(destinations ...TransferPath) *sendClientTransport {
return NewSendClientTransportWithComplement(false, destinations...)
}
func NewSendClientTransportWithComplement(complement bool, destinations ...TransferPath) *sendClientTransport {
destinations_ := map[TransferPath]bool{}
for _, destination := range destinations {
destinations_[destination] = true
}
return &sendClientTransport{
transportId: NewId(),
complement: complement,
destinations: destinations_,
}
}
func (self *sendClientTransport) TransportId() Id {
return self.transportId
}
func (self *sendClientTransport) Priority() int {
return 100
}
func (self *sendClientTransport) Weight() float32 {
return 0
}
func (self *sendClientTransport) CanEvalRouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) bool {
return true
}
func (self *sendClientTransport) RouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) float32 {
// uniform weight
return 1.0 / float32(1+len(remainingStats))
}
func (self *sendClientTransport) MatchesSend(destination TransferPath) bool {
return self.complement != self.destinations[destination]
}
func (self *sendClientTransport) MatchesReceive(destination TransferPath) bool {
return false
}
func (self *sendClientTransport) Downgrade(source TransferPath) {
// nothing to downgrade
}
// conforms to `Transport`
type sendGatewayTransport struct {
transportId Id
}
func NewSendGatewayTransport() *sendGatewayTransport {
return &sendGatewayTransport{
transportId: NewId(),
}
}
func (self *sendGatewayTransport) TransportId() Id {
return self.transportId
}
func (self *sendGatewayTransport) Priority() int {
return 100
}
func (self *sendGatewayTransport) Weight() float32 {
return 0
}
func (self *sendGatewayTransport) CanEvalRouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) bool {
return true
}
func (self *sendGatewayTransport) RouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) float32 {
// uniform weight
return 1.0 / float32(1+len(remainingStats))
}
func (self *sendGatewayTransport) MatchesSend(destination TransferPath) bool {
return true
}
func (self *sendGatewayTransport) MatchesReceive(destination TransferPath) bool {
return false
}
func (self *sendGatewayTransport) Downgrade(source TransferPath) {
// nothing to downgrade
}
// conforms to `Transport`
type receiveGatewayTransport struct {
transportId Id
}
func NewReceiveGatewayTransport() *receiveGatewayTransport {
return &receiveGatewayTransport{
transportId: NewId(),
}
}
func (self *receiveGatewayTransport) TransportId() Id {
return self.transportId
}
func (self *receiveGatewayTransport) Priority() int {
return 100
}
func (self *receiveGatewayTransport) Weight() float32 {
return 0
}
func (self *receiveGatewayTransport) CanEvalRouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) bool {
return true
}
func (self *receiveGatewayTransport) RouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) float32 {
// uniform weight
return 1.0 / float32(1+len(remainingStats))
}
func (self *receiveGatewayTransport) MatchesSend(destination TransferPath) bool {
return false
}
func (self *receiveGatewayTransport) MatchesReceive(destination TransferPath) bool {
return true
}
func (self *receiveGatewayTransport) Downgrade(source TransferPath) {
// nothing to downgrade
}
// conforms to `Transport`
type prioritySendGatewayTransport struct {
transportId Id
priority int
weight float32
}
func NewPrioritySendGatewayTransport(priority int, weight float32) *prioritySendGatewayTransport {
return &prioritySendGatewayTransport{
transportId: NewId(),
priority: priority,
weight: weight,
}
}
func (self *prioritySendGatewayTransport) TransportId() Id {
return self.transportId
}
func (self *prioritySendGatewayTransport) Priority() int {
return self.priority
}
func (self *prioritySendGatewayTransport) Weight() float32 {
return self.weight
}
func (self *prioritySendGatewayTransport) CanEvalRouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) bool {
return true
}
func (self *prioritySendGatewayTransport) RouteWeight(stats *RouteStats, remainingStats map[Transport]*RouteStats) float32 {
netWeight := self.weight
for t, _ := range remainingStats {
netWeight += t.Weight()
}
if 0 < netWeight {
return self.weight / netWeight
} else {