feat(alerting): refactoring

pkg/services/alerting/eval_handler.go

@@ -0,0 +1,59 @@
+package alerting
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/grafana/grafana/pkg/log"
+)
+
+var (
+	descriptionFmt = "Actual value: %1.2f for %s. "
+)
+
+type DefaultEvalHandler struct {
+	log             log.Logger
+	alertJobTimeout time.Duration
+}
+
+func NewEvalHandler() *DefaultEvalHandler {
+	return &DefaultEvalHandler{
+		log:             log.New("alerting.handler"),
+		alertJobTimeout: time.Second * 5,
+	}
+}
+
+func (e *DefaultEvalHandler) Eval(context *EvalContext) {
+
+	go e.eval(context)
+
+	select {
+	case <-time.After(e.alertJobTimeout):
+		context.Error = fmt.Errorf("Timeout")
+		context.EndTime = time.Now()
+		e.log.Debug("Job Execution timeout", "alertId", context.Rule.Id)
+	case <-context.DoneChan:
+		e.log.Debug("Job Execution done", "timeMs", context.GetDurationMs(), "alertId", context.Rule.Id, "firing", context.Firing)
+	}
+
+}
+
+func (e *DefaultEvalHandler) eval(context *EvalContext) {
+
+	for _, condition := range context.Rule.Conditions {
+		condition.Eval(context)
+
+		// break if condition could not be evaluated
+		if context.Error != nil {
+			break
+		}
+
+		// break if result has not triggered yet
+		if context.Firing == false {
+			break
+		}
+	}
+
+	context.EndTime = time.Now()
+	context.DoneChan <- true
+}