recorder implementations

pkg/util/util.go

@@ -1,6 +1,19 @@
 package util
 
-import "k8s.io/utils/ptr"
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"fmt"
+	"slices"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
+	"k8s.io/utils/ptr"
+
+	pb "gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/api/v1alpha1/weather"
+	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/weather"
+)
+
+const defaultLimit = -1
 
 func DerefStr(s *string) string {
 	if s == nil {
@@ -15,3 +28,77 @@ func Int32ptr(i *int) *int32 {
 	}
 	return ptr.To(int32(*i))
 }
+
+// Generates a hash that will be consistent
+// across all running replicas
+func GetAppHash(conf *config.AppConfig) string {
+	hashName := fmt.Sprintf("%s-%s-%s",
+		conf.Name,
+		conf.Environment,
+		conf.Version,
+	)
+
+	hash := md5.Sum([]byte(hashName))
+	return hex.EncodeToString(hash[:])
+}
+
+// Get a limit from req, applying a default if unset or not sane
+func GetLimitFromReq(req *pb.GetWeatherRequest) int {
+	if req == nil || req.Limit == nil {
+		return defaultLimit
+	}
+
+	if req.GetLimit() == 0 {
+		return defaultLimit
+	}
+
+	return int(req.GetLimit())
+}
+
+// Simple helper to trim a list of updates
+func LimitUpdates(updates []*weather.WeatherUpdate, limit int) []*weather.WeatherUpdate {
+	if limit < 0 {
+		return updates // No limit
+	}
+
+	if len(updates) > limit {
+		return updates[len(updates)-limit:] // Trim to limit
+	}
+
+	return updates // Within limit
+}
+
+func ApplyOptsToUpdates(updates []*weather.WeatherUpdate, limit int, opts *pb.GetWeatherOpts) []*weather.WeatherUpdate {
+	if opts == nil {
+		return updates
+	} else if opts.StationName == nil && opts.StationType == nil {
+		return updates
+	}
+
+	filtered := make([]*weather.WeatherUpdate, 0, limit)
+
+	for i := len(updates) - 1; i >= 0; i-- {
+		update := updates[i]
+		match := true
+
+		if opts.GetStationName() != "" {
+			if update.GetStationName() != opts.GetStationName() {
+				match = false
+			}
+		}
+		if opts.GetStationType() != "" {
+			if DerefStr(update.StationType) != opts.GetStationType() {
+				match = false
+			}
+		}
+
+		if match {
+			filtered = append(filtered, update)
+			if limit > 0 && len(filtered) >= limit {
+				return slices.Clip(filtered)
+			}
+		}
+	}
+
+	return slices.Clip(filtered)
+}