nip45: hyperlolog small fixes and improvements. support deterministic offset for hardcoded set of queries.

nip45/hll_event.go

@@ -0,0 +1,42 @@
+package nip45
+
+import (
+	"iter"
+	"strconv"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+func HyperLogLogEventPubkeyOffsetsAndReferencesForEvent(evt *nostr.Event) iter.Seq2[string, int] {
+	return func(yield func(string, int) bool) {
+		switch evt.Kind {
+		case 3:
+			//
+			// follower counts
+			for _, tag := range evt.Tags {
+				if len(tag) >= 2 && tag[0] == "p" && nostr.IsValid32ByteHex(tag[1]) {
+					// 32th nibble of each "p" tag
+					p, _ := strconv.ParseInt(tag[1][32:33], 16, 64)
+					if !yield(tag[1], int(p+8)) {
+						return
+					}
+				}
+			}
+		case 7:
+			//
+			// reaction counts:
+			// (only the last "e" tag counts)
+			lastE := evt.Tags.GetLast([]string{"e", ""})
+			if lastE != nil {
+				v := (*lastE)[1]
+				if nostr.IsValid32ByteHex(v) {
+					// 32th nibble of "e" tag
+					p, _ := strconv.ParseInt(v[32:33], 16, 64)
+					if !yield(v, int(p+8)) {
+						return
+					}
+				}
+			}
+		}
+	}
+}