for _, document := range this.pending {
go this.persist(document)
}
this.waiter.Wait()
}
func (this *Handler) persist(document projector.Document) {
started := clock.UTCNow()
this.writer.Write(document)
metrics.Measure(DocumentWriteLatency, milliseconds(time.Since(started)))
this.waiter.Done()
}
func milliseconds(duration time.Duration) int64 { return microseconds(duration) / 1000 }
func microseconds(duration time.Duration) int64 { return int64(duration.Nanoseconds() / 1000) }
func (this *Handler) sendLatestAcknowledgement(receipt interface{}) {
this.output <- receipt
}
func (this *Handler) prepareForNextBatch() {
this.pending = make(map[string]projector.Document)
}
var (
DepthPersistQueue = metrics.AddGauge("pipeline:persist-phase-backlog-depth", time.Second*300)
DocumentsToSave = metrics.AddGauge("pipeline:documents-to-save", time.Second*300)
DocumentWriteLatency = metrics.AddGauge("pipeline:document-write-latency-milliseconds", time.Second*300)
)
input <-chan messaging.Delivery
output chan<- projector.DocumentMessage
transformer Transformer
clock *clock.Clock
}
func NewHandler(input <-chan messaging.Delivery, output chan<- projector.DocumentMessage, transformer Transformer) *Handler {
return &Handler{input: input, output: output, transformer: transformer}
}
func (this *Handler) Listen() {
for message := range this.input {
now := this.clock.UTCNow()
metrics.Measure(transformQueueDepth, int64(len(this.input)))
this.transformer.TransformAllDocuments(message.Message, now)
if len(this.input) == 0 {
this.output <- projector.DocumentMessage{
Receipt: message.Receipt,
Documents: this.transformer.Collect(),
}
}
}
close(this.output)
}
var transformQueueDepth = metrics.AddGauge("pipeline:transform-phase-backlog-depth", time.Second*30)