Improve metrics recording

pkg/weather/metrics_record.go

@@ -0,0 +1,104 @@
+package weather
+
+import (
+	"context"
+	"errors"
+
+	"github.com/rs/zerolog"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+)
+
+type MetricRecorder struct {
+	ctx context.Context
+	l   *zerolog.Logger
+}
+
+type RecordOpts struct {
+	Float64Gauge metric.Float64Gauge
+	Int64Gauge   metric.Int64Gauge
+	IntVal       *int
+	FloatVal     *float64
+	Attributes   []attribute.KeyValue
+	Field        WeatherUpdateField
+	StationInfo  *StationInfo
+}
+
+func (r *MetricRecorder) Record(opts *RecordOpts) {
+	if opts.StationInfo != nil && !opts.keep() {
+		r.l.Trace().
+			Str("field", string(opts.Field)).
+			Str("station", *opts.StationInfo.Name).
+			Msg("Metric dropped by station config")
+		return
+	} else if opts.Int64Gauge == nil && opts.Float64Gauge == nil {
+		r.l.Err(errors.New("neither int nor float gauge provided")).Send()
+		return
+	}
+
+	if opts.Int64Gauge != nil {
+		if opts.IntVal == nil {
+			log := r.l.Trace().Str("field", string(opts.Field))
+			if opts.StationInfo != nil {
+				log = log.Str("station", *opts.StationInfo.Name)
+			}
+			log.Msg("Dropping nil int metric")
+			return
+		}
+		r.recordInt(opts.Int64Gauge, *opts.IntVal, opts.Attributes...)
+	} else if opts.Float64Gauge != nil {
+		if opts.FloatVal == nil {
+			log := r.l.Trace().Str("field", string(opts.Field))
+			if opts.StationInfo != nil {
+				log = log.Str("station", *opts.StationInfo.Name)
+			}
+			log.Msg("Dropping nil float metric")
+			return
+		}
+		r.recordFloat(opts.Float64Gauge, *opts.FloatVal, opts.Attributes...)
+	}
+}
+
+func (o *RecordOpts) keep() bool {
+	// If keep fields are given, only check keep fields
+	if len(o.StationInfo.Keep) > 0 {
+		for _, f := range o.StationInfo.Keep {
+			if f == o.Field {
+				return true
+			}
+		}
+		return false
+	}
+
+	for _, f := range o.StationInfo.Drop {
+		if f == o.Field {
+			return false
+		}
+	}
+	return true
+}
+
+func (r *MetricRecorder) recordInt(
+	m metric.Int64Gauge, value int, attributes ...attribute.KeyValue,
+) {
+	// Prepare metric attributes
+	options := make([]metric.RecordOption, 0, len(attributes))
+	if len(attributes) > 0 {
+		options = append(options, metric.WithAttributes(attributes...))
+	}
+
+	val := int64(value)
+	m.Record(r.ctx, val, options...)
+}
+
+func (r *MetricRecorder) recordFloat(
+	m metric.Float64Gauge, value float64, attributes ...attribute.KeyValue,
+) {
+	// Prepare metric attributes
+	options := make([]metric.RecordOption, 0, len(attributes))
+	if len(attributes) > 0 {
+		options = append(options, metric.WithAttributes(attributes...))
+	}
+
+	m.Record(r.ctx, value, options...)
+}