More lightweight notifications

This commit is contained in:
Neil Alexander 2021-01-07 13:48:32 +00:00
parent 875cb2c379
commit a6549669ca
No known key found for this signature in database
GPG key ID: A02A2019A2BB0944
4 changed files with 83 additions and 75 deletions

View file

@ -6,18 +6,25 @@ import (
"github.com/matrix-org/dendrite/syncapi/storage"
"github.com/matrix-org/dendrite/syncapi/types"
userapi "github.com/matrix-org/dendrite/userapi/api"
)
type PartitionedStreamProvider struct {
DB storage.Database
latest types.LogPosition
latestMutex sync.RWMutex
update *sync.Cond
DB storage.Database
latest types.LogPosition
latestMutex sync.RWMutex
subscriptions map[string]*partitionedStreamSubscription // userid+deviceid
subscriptionsMutex sync.Mutex
}
type partitionedStreamSubscription struct {
ctx context.Context
from types.LogPosition
ch chan struct{}
}
func (p *PartitionedStreamProvider) Setup() {
locker := &sync.Mutex{}
p.update = sync.NewCond(locker)
p.subscriptions = make(map[string]*partitionedStreamSubscription)
}
func (p *PartitionedStreamProvider) Advance(
@ -28,7 +35,22 @@ func (p *PartitionedStreamProvider) Advance(
if latest.IsAfter(&p.latest) {
p.latest = latest
p.update.Broadcast()
p.subscriptionsMutex.Lock()
for id, s := range p.subscriptions {
select {
case <-s.ctx.Done():
close(s.ch)
delete(p.subscriptions, id)
continue
default:
if latest.IsAfter(&s.from) {
close(s.ch)
delete(p.subscriptions, id)
}
}
}
p.subscriptionsMutex.Unlock()
}
}
@ -43,6 +65,7 @@ func (p *PartitionedStreamProvider) LatestPosition(
func (p *PartitionedStreamProvider) NotifyAfter(
ctx context.Context,
device *userapi.Device,
from types.LogPosition,
) chan struct{} {
ch := make(chan struct{})
@ -63,32 +86,13 @@ func (p *PartitionedStreamProvider) NotifyAfter(
return ch
}
// If we haven't, then we'll subscribe to updates. The
// sync.Cond will fire every time the latest position
// updates, so we can check and see if we've advanced
// past it.
go func(p *PartitionedStreamProvider) {
p.update.L.Lock()
defer p.update.L.Unlock()
for {
select {
case <-ctx.Done():
// The context has expired, so there's no point
// in continuing to wait for the update.
close(ch)
return
default:
// The latest position has been advanced. Let's
// see if it's advanced to the position we care
// about. If it has then we'll return.
p.update.Wait()
if check() {
return
}
}
}
}(p)
id := device.UserID + device.ID
p.subscriptionsMutex.Lock()
if s, ok := p.subscriptions[id]; ok {
close(s.ch)
}
p.subscriptions[id] = &partitionedStreamSubscription{ctx, from, ch}
p.subscriptionsMutex.Unlock()
return ch
}

View file

@ -6,18 +6,25 @@ import (
"github.com/matrix-org/dendrite/syncapi/storage"
"github.com/matrix-org/dendrite/syncapi/types"
userapi "github.com/matrix-org/dendrite/userapi/api"
)
type StreamProvider struct {
DB storage.Database
latest types.StreamPosition
latestMutex sync.RWMutex
update *sync.Cond
DB storage.Database
latest types.StreamPosition
latestMutex sync.RWMutex
subscriptions map[string]*streamSubscription // userid+deviceid
subscriptionsMutex sync.Mutex
}
type streamSubscription struct {
ctx context.Context
from types.StreamPosition
ch chan struct{}
}
func (p *StreamProvider) Setup() {
locker := &sync.Mutex{}
p.update = sync.NewCond(locker)
p.subscriptions = make(map[string]*streamSubscription)
}
func (p *StreamProvider) Advance(
@ -28,7 +35,22 @@ func (p *StreamProvider) Advance(
if latest > p.latest {
p.latest = latest
p.update.Broadcast()
p.subscriptionsMutex.Lock()
for id, s := range p.subscriptions {
select {
case <-s.ctx.Done():
close(s.ch)
delete(p.subscriptions, id)
continue
default:
if latest > s.from {
close(s.ch)
delete(p.subscriptions, id)
}
}
}
p.subscriptionsMutex.Unlock()
}
}
@ -43,6 +65,7 @@ func (p *StreamProvider) LatestPosition(
func (p *StreamProvider) NotifyAfter(
ctx context.Context,
device *userapi.Device,
from types.StreamPosition,
) chan struct{} {
ch := make(chan struct{})
@ -63,32 +86,13 @@ func (p *StreamProvider) NotifyAfter(
return ch
}
// If we haven't, then we'll subscribe to updates. The
// sync.Cond will fire every time the latest position
// updates, so we can check and see if we've advanced
// past it.
go func(p *StreamProvider) {
p.update.L.Lock()
defer p.update.L.Unlock()
for {
select {
case <-ctx.Done():
// The context has expired, so there's no point
// in continuing to wait for the update.
close(ch)
return
default:
// The latest position has been advanced. Let's
// see if it's advanced to the position we care
// about. If it has then we'll return.
p.update.Wait()
if check() {
return
}
}
}
}(p)
id := device.UserID + device.ID
p.subscriptionsMutex.Lock()
if s, ok := p.subscriptions[id]; ok {
close(s.ch)
}
p.subscriptions[id] = &streamSubscription{ctx, from, ch}
p.subscriptionsMutex.Unlock()
return ch
}

View file

@ -176,13 +176,13 @@ func (rp *RequestPool) OnIncomingSyncRequest(req *http.Request, device *userapi.
case <-timer.C: // Timeout reached
return giveup()
case <-rp.streams.PDUStreamProvider.NotifyAfter(waitctx, syncReq.Since.PDUPosition):
case <-rp.streams.TypingStreamProvider.NotifyAfter(waitctx, syncReq.Since.TypingPosition):
case <-rp.streams.ReceiptStreamProvider.NotifyAfter(waitctx, syncReq.Since.ReceiptPosition):
case <-rp.streams.InviteStreamProvider.NotifyAfter(waitctx, syncReq.Since.InvitePosition):
case <-rp.streams.SendToDeviceStreamProvider.NotifyAfter(waitctx, syncReq.Since.SendToDevicePosition):
case <-rp.streams.AccountDataStreamProvider.NotifyAfter(waitctx, syncReq.Since.AccountDataPosition):
case <-rp.streams.DeviceListStreamProvider.NotifyAfter(waitctx, syncReq.Since.DeviceListPosition):
case <-rp.streams.PDUStreamProvider.NotifyAfter(waitctx, device, syncReq.Since.PDUPosition):
case <-rp.streams.TypingStreamProvider.NotifyAfter(waitctx, device, syncReq.Since.TypingPosition):
case <-rp.streams.ReceiptStreamProvider.NotifyAfter(waitctx, device, syncReq.Since.ReceiptPosition):
case <-rp.streams.InviteStreamProvider.NotifyAfter(waitctx, device, syncReq.Since.InvitePosition):
case <-rp.streams.SendToDeviceStreamProvider.NotifyAfter(waitctx, device, syncReq.Since.SendToDevicePosition):
case <-rp.streams.AccountDataStreamProvider.NotifyAfter(waitctx, device, syncReq.Since.AccountDataPosition):
case <-rp.streams.DeviceListStreamProvider.NotifyAfter(waitctx, device, syncReq.Since.DeviceListPosition):
}
syncReq.Log.Println("Responding to sync after wakeup")

View file

@ -42,7 +42,7 @@ type StreamProvider interface {
// NotifyAfter returns a channel which will be closed once the
// stream advances past the "from" position.
NotifyAfter(ctx context.Context, from StreamPosition) chan struct{}
NotifyAfter(ctx context.Context, device *userapi.Device, from StreamPosition) chan struct{}
// LatestPosition returns the latest stream position for this stream.
LatestPosition(ctx context.Context) StreamPosition
@ -53,6 +53,6 @@ type PartitionedStreamProvider interface {
Advance(latest LogPosition)
CompleteSync(ctx context.Context, req *SyncRequest) LogPosition
IncrementalSync(ctx context.Context, req *SyncRequest, from, to LogPosition) LogPosition
NotifyAfter(ctx context.Context, from LogPosition) chan struct{}
NotifyAfter(ctx context.Context, device *userapi.Device, from LogPosition) chan struct{}
LatestPosition(ctx context.Context) LogPosition
}