func (sws *serverWatchStream) sendLoop() {
// watch ids that are currently active
ids := make(map[mvcc.WatchID]struct{})
// watch responses pending on a watch id creation message
pending := make(map[mvcc.WatchID][]*pb.WatchResponse)
interval := GetProgressReportInterval()
progressTicker := time.NewTicker(interval)
defer func() {
progressTicker.Stop()
// drain the chan to clean up pending events
for ws := range sws.watchStream.Chan() {
mvcc.ReportEventReceived(len(ws.Events))
}
for _, wrs := range pending {
for _, ws := range wrs {
mvcc.ReportEventReceived(len(ws.Events))
}
}
}()
for {
select {
case wresp, ok := <-sws.watchStream.Chan():
if !ok {
return
}
// TODO: evs is []mvccpb.Event type
// either return []*mvccpb.Event from the mvcc package
// or define protocol buffer with []mvccpb.Event.
evs := wresp.Events
events := make([]*mvccpb.Event, len(evs))
sws.mu.Lock()
needPrevKV := sws.prevKV[wresp.WatchID]
sws.mu.Unlock()
for i := range evs {
events[i] = &evs[i]
if needPrevKV {
opt := mvcc.RangeOptions{Rev: evs[i].Kv.ModRevision - 1}
r, err := sws.watchable.Range(evs[i].Kv.Key, nil, opt)
if err == nil && len(r.KVs) != 0 {
events[i].PrevKv = &(r.KVs[0])
}
}
}
wr := &pb.WatchResponse{
Header: sws.newResponseHeader(wresp.Revision),
WatchId: int64(wresp.WatchID),
Events: events,
CompactRevision: wresp.CompactRevision,
}
if _, hasId := ids[wresp.WatchID]; !hasId {
// buffer if id not yet announced
wrs := append(pending[wresp.WatchID], wr)
pending[wresp.WatchID] = wrs
continue
}
mvcc.ReportEventReceived(len(evs))
if err := sws.gRPCStream.Send(wr); err != nil {
return
}
sws.mu.Lock()
if len(evs) > 0 && sws.progress[wresp.WatchID] {
// elide next progress update if sent a key update
sws.progress[wresp.WatchID] = false
}
sws.mu.Unlock()
case c, ok := <-sws.ctrlStream:
if !ok {
return
}
if err := sws.gRPCStream.Send(c); err != nil {
return
}
// track id creation
wid := mvcc.WatchID(c.WatchId)
if c.Canceled {
delete(ids, wid)
continue
}
if c.Created {
// flush buffered events
ids[wid] = struct{}{}
for _, v := range pending[wid] {
mvcc.ReportEventReceived(len(v.Events))
if err := sws.gRPCStream.Send(v); err != nil {
return
}
}
delete(pending, wid)
}
case <-progressTicker.C:
sws.mu.Lock()
for id, ok := range sws.progress {
if ok {
sws.watchStream.RequestProgress(id)
}
sws.progress[id] = true
}
sws.mu.Unlock()
case <-sws.closec:
return
}
}
}
func (sws *serverWatchStream) recvLoop() error {
for {
req, err := sws.gRPCStream.Recv()
if err == io.EOF {
return nil
}
if err != nil {
return err
}
switch uv := req.RequestUnion.(type) {
case *pb.WatchRequest_CreateRequest:
if uv.CreateRequest == nil {
break
}
creq := uv.CreateRequest
if len(creq.Key) == 0 {
// \x00 is the smallest key
creq.Key = []byte{0}
}
if len(creq.RangeEnd) == 1 && creq.RangeEnd[0] == 0 {
// support >= key queries
creq.RangeEnd = []byte{}
}
wsrev := sws.watchStream.Rev()
rev := creq.StartRevision
if rev == 0 {
rev = wsrev + 1
}
id := sws.watchStream.Watch(creq.Key, creq.RangeEnd, rev)
if id != -1 && creq.ProgressNotify {
sws.progress[id] = true
}
sws.ctrlStream <- &pb.WatchResponse{
Header: sws.newResponseHeader(wsrev),
WatchId: int64(id),
Created: true,
Canceled: id == -1,
}
case *pb.WatchRequest_CancelRequest:
if uv.CancelRequest != nil {
id := uv.CancelRequest.WatchId
err := sws.watchStream.Cancel(mvcc.WatchID(id))
if err == nil {
sws.ctrlStream <- &pb.WatchResponse{
Header: sws.newResponseHeader(sws.watchStream.Rev()),
WatchId: id,
Canceled: true,
}
sws.mu.Lock()
delete(sws.progress, mvcc.WatchID(id))
sws.mu.Unlock()
}
}
// TODO: do we need to return error back to client?
default:
panic("not implemented")
}
}
}
func (sws *serverWatchStream) recvLoop() error {
for {
req, err := sws.gRPCStream.Recv()
if err == io.EOF {
return nil
}
if err != nil {
return err
}
switch uv := req.RequestUnion.(type) {
case *pb.WatchRequest_CreateRequest:
if uv.CreateRequest == nil {
break
}
creq := uv.CreateRequest
if len(creq.Key) == 0 {
// \x00 is the smallest key
creq.Key = []byte{0}
}
if len(creq.RangeEnd) == 1 && creq.RangeEnd[0] == 0 {
// support >= key queries
creq.RangeEnd = []byte{}
}
filters := FiltersFromRequest(creq)
wsrev := sws.watchStream.Rev()
rev := creq.StartRevision
if rev == 0 {
rev = wsrev + 1
}
id := sws.watchStream.Watch(creq.Key, creq.RangeEnd, rev, filters...)
if id != -1 {
sws.mu.Lock()
if creq.ProgressNotify {
sws.progress[id] = true
}
if creq.PrevKv {
sws.prevKV[id] = true
}
sws.mu.Unlock()
}
wr := &pb.WatchResponse{
Header: sws.newResponseHeader(wsrev),
WatchId: int64(id),
Created: true,
Canceled: id == -1,
}
select {
case sws.ctrlStream <- wr:
case <-sws.closec:
return nil
}
case *pb.WatchRequest_CancelRequest:
if uv.CancelRequest != nil {
id := uv.CancelRequest.WatchId
err := sws.watchStream.Cancel(mvcc.WatchID(id))
if err == nil {
sws.ctrlStream <- &pb.WatchResponse{
Header: sws.newResponseHeader(sws.watchStream.Rev()),
WatchId: id,
Canceled: true,
}
sws.mu.Lock()
delete(sws.progress, mvcc.WatchID(id))
delete(sws.prevKV, mvcc.WatchID(id))
sws.mu.Unlock()
}
}
default:
// we probably should not shutdown the entire stream when
// receive an valid command.
// so just do nothing instead.
continue
}
}
}
func (sws *serverWatchStream) recvLoop() error {
defer close(sws.ctrlStream)
for {
req, err := sws.gRPCStream.Recv()
if err == io.EOF {
return nil
}
if err != nil {
return err
}
switch uv := req.RequestUnion.(type) {
case *pb.WatchRequest_CreateRequest:
if uv.CreateRequest == nil {
break
}
creq := uv.CreateRequest
if len(creq.Key) == 0 {
// \x00 is the smallest key
creq.Key = []byte{0}
}
if len(creq.RangeEnd) == 1 && creq.RangeEnd[0] == 0 {
// support >= key queries
creq.RangeEnd = []byte{}
}
filters := make([]mvcc.FilterFunc, 0, len(creq.Filters))
for _, ft := range creq.Filters {
switch ft {
case pb.WatchCreateRequest_NOPUT:
filters = append(filters, filterNoPut)
case pb.WatchCreateRequest_NODELETE:
filters = append(filters, filterNoDelete)
default:
}
}
wsrev := sws.watchStream.Rev()
rev := creq.StartRevision
if rev == 0 {
rev = wsrev + 1
}
id := sws.watchStream.Watch(creq.Key, creq.RangeEnd, rev, filters...)
if id != -1 && creq.ProgressNotify {
sws.progress[id] = true
}
wr := &pb.WatchResponse{
Header: sws.newResponseHeader(wsrev),
WatchId: int64(id),
Created: true,
Canceled: id == -1,
}
select {
case sws.ctrlStream <- wr:
case <-sws.closec:
return nil
}
case *pb.WatchRequest_CancelRequest:
if uv.CancelRequest != nil {
id := uv.CancelRequest.WatchId
err := sws.watchStream.Cancel(mvcc.WatchID(id))
if err == nil {
sws.ctrlStream <- &pb.WatchResponse{
Header: sws.newResponseHeader(sws.watchStream.Rev()),
WatchId: id,
Canceled: true,
}
sws.mu.Lock()
delete(sws.progress, mvcc.WatchID(id))
sws.mu.Unlock()
}
}
// TODO: do we need to return error back to client?
default:
panic("not implemented")
}
}
}