func()

in banyand/query/processor.go [59:142]
80 lines of code
16 McCabe index (conditional complexity)

func (p *streamQueryProcessor) Rev(ctx context.Context, message bus.Message) (resp bus.Message) {
	n := time.Now()
	now := n.UnixNano()
	queryCriteria, ok := message.Data().(*streamv1.QueryRequest)
	if !ok {
		resp = bus.NewMessage(bus.MessageID(now), common.NewError("invalid event data type"))
		return
	}
	if p.log.Debug().Enabled() {
		p.log.Debug().RawJSON("criteria", logger.Proto(queryCriteria)).Msg("received a query request")
	}
	defer func() {
		if err := recover(); err != nil {
			p.log.Error().Interface("err", err).RawJSON("req", logger.Proto(queryCriteria)).Str("stack", string(debug.Stack())).Msg("panic")
			resp = bus.NewMessage(bus.MessageID(time.Now().UnixNano()), common.NewError("panic"))
		}
	}()
	if len(queryCriteria.Groups) > 1 {
		resp = bus.NewMessage(bus.MessageID(now), common.NewError("only support one group in the query request"))
		return
	}
	meta := &commonv1.Metadata{
		Name:  queryCriteria.Name,
		Group: queryCriteria.Groups[0],
	}
	ec, err := p.streamService.Stream(meta)
	if err != nil {
		resp = bus.NewMessage(bus.MessageID(now), common.NewError("fail to get execution context for stream %s: %v", meta.GetName(), err))
		return
	}
	s, err := logical_stream.BuildSchema(ec.GetSchema(), ec.GetIndexRules())
	if err != nil {
		resp = bus.NewMessage(bus.MessageID(now), common.NewError("fail to build schema for stream %s: %v", meta.GetName(), err))
		return
	}

	plan, err := logical_stream.Analyze(ctx, queryCriteria, meta, s)
	if err != nil {
		resp = bus.NewMessage(bus.MessageID(now), common.NewError("fail to analyze the query request for stream %s: %v", meta.GetName(), err))
		return
	}

	if p.log.Debug().Enabled() {
		p.log.Debug().Str("plan", plan.String()).Msg("query plan")
	}
	var tracer *query.Tracer
	var span *query.Span
	if queryCriteria.Trace {
		tracer, ctx = query.NewTracer(ctx, n.Format(time.RFC3339Nano))
		span, ctx = tracer.StartSpan(ctx, "data-%s", p.queryService.nodeID)
		span.Tag("plan", plan.String())
		defer func() {
			data := resp.Data()
			switch d := data.(type) {
			case *streamv1.QueryResponse:
				d.Trace = tracer.ToProto()
			case *common.Error:
				span.Error(errors.New(d.Error()))
				resp = bus.NewMessage(bus.MessageID(now), &measurev1.QueryResponse{Trace: tracer.ToProto()})
			default:
				panic("unexpected data type")
			}
			span.Stop()
		}()
	}
	se := plan.(executor.StreamExecutable)
	defer se.Close()
	entities, err := se.Execute(executor.WithStreamExecutionContext(ctx, ec))
	if err != nil {
		p.log.Error().Err(err).RawJSON("req", logger.Proto(queryCriteria)).Msg("fail to execute the query plan")
		resp = bus.NewMessage(bus.MessageID(now), common.NewError("execute the query plan for stream %s: %v", meta.GetName(), err))
		return
	}

	resp = bus.NewMessage(bus.MessageID(now), &streamv1.QueryResponse{Elements: entities})

	if !queryCriteria.Trace && p.slowQuery > 0 {
		latency := time.Since(n)
		if latency > p.slowQuery {
			p.log.Warn().Dur("latency", latency).RawJSON("req", logger.Proto(queryCriteria)).Int("resp_count", len(entities)).Msg("stream slow query")
		}
	}
	return
}