ipld-eth-beacon-indexer/pkg/beaconclient/incomingsse.go
Abdul Rabbani 67f1427c8b Allow the application to process events in parallel
there is a main thread that tracks incoming messages, but then it spawns goroutines to actually process each slot so that they can happen concurrently.
2022-05-16 11:49:23 -04:00

83 lines
2.2 KiB
Go

// This package will handle all event subscriptions that utilize SSE.
package beaconclient
import (
"encoding/json"
"time"
log "github.com/sirupsen/logrus"
"github.com/vulcanize/ipld-ethcl-indexer/pkg/loghelper"
"golang.org/x/sync/errgroup"
)
var (
shutdownWaitInterval = time.Duration(5) * time.Second
)
// This function will capture all the SSE events for a given SseEvents object.
// When new messages come in, it will ensure that they are decoded into JSON.
// If any errors occur, it log the error information.
func handleIncomingSseEvent[P ProcessedEvents](eventHandler *SseEvents[P]) {
go func() {
errG := new(errgroup.Group)
errG.Go(func() error {
err := eventHandler.SseClient.SubscribeChanRaw(eventHandler.MessagesCh)
if err != nil {
return err
}
return nil
})
if err := errG.Wait(); err != nil {
log.WithFields(log.Fields{
"err": err,
"endpoint": eventHandler.Endpoint,
}).Error("Unable to subscribe to the SSE endpoint.")
return
} else {
loghelper.LogEndpoint(eventHandler.Endpoint).Info("Successfully subscribed to the event stream.")
}
}()
for {
select {
case message := <-eventHandler.MessagesCh:
// Message can be nil if its a keep-alive message
if len(message.Data) != 0 {
log.WithFields(log.Fields{"msg": string(message.Data)}).Debug("We are going to send the following message to be processed.")
go processMsg(message.Data, eventHandler.ProcessCh, eventHandler.ErrorCh)
}
case headErr := <-eventHandler.ErrorCh:
log.WithFields(log.Fields{
"endpoint": eventHandler.Endpoint,
"err": headErr.err,
"msg": headErr.msg,
},
).Error("Unable to handle event.")
}
}
}
// Turn the data object into a Struct.
func processMsg[P ProcessedEvents](msg []byte, processCh chan<- *P, errorCh chan<- *SseError) {
var msgMarshaled P
err := json.Unmarshal(msg, &msgMarshaled)
if err != nil {
loghelper.LogError(err).Error("Unable to parse message")
errorCh <- &SseError{
err: err,
msg: msg,
}
return
}
processCh <- &msgMarshaled
}
// Capture all of the event topics.
func (bc *BeaconClient) captureEventTopic() {
log.Info("We are capturing all SSE events")
go handleIncomingSseEvent(bc.HeadTracking)
go handleIncomingSseEvent(bc.ReOrgTracking)
}