wip: grib

internal/pkg/grib/util.go

@@ -0,0 +1,26 @@
+package grib
+
+import (
+	"fmt"
+	"hash/fnv"
+	"time"
+)
+
+var steps = []int{0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48}
+
+func nearestRun(t time.Time) time.Time {
+	h := t.UTC().Hour() - t.UTC().Hour()%6
+	return time.Date(t.Year(), t.Month(), t.Day(), h, 0, 0, 0, time.UTC)
+}
+
+func fileName(run time.Time, step int) string {
+	return fmt.Sprintf("gfs.t%02dz.pgrb2.0p50.f%03d", run.Hour(), step)
+}
+
+func encodeKey(a ...any) uint64 {
+	h := fnv.New64a()
+	for _, v := range a {
+		fmt.Fprint(h, v)
+	}
+	return h.Sum64()
+}