sdk/hints: add lmdb implementation.

sdk/hints/lmdbh/keys.go

@@ -0,0 +1,40 @@
+package lmdbh
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"unsafe"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+func encodeKey(pubhintkey, relay string) []byte {
+	k := make([]byte, 32+len(relay))
+	hex.Decode(k[0:32], []byte(pubhintkey))
+	copy(k[32:], unsafe.Slice(unsafe.StringData(relay), len(relay)))
+	return k
+}
+
+func parseKey(k []byte) (pubkey string, relay string) {
+	pubkey = hex.EncodeToString(k[0:32])
+	relay = string(k[32:])
+	return
+}
+
+func encodeValue(tss timestamps) []byte {
+	v := make([]byte, 16)
+	binary.LittleEndian.PutUint32(v[0:], uint32(tss[0]))
+	binary.LittleEndian.PutUint32(v[4:], uint32(tss[1]))
+	binary.LittleEndian.PutUint32(v[8:], uint32(tss[2]))
+	binary.LittleEndian.PutUint32(v[12:], uint32(tss[3]))
+	return v
+}
+
+func parseValue(v []byte) timestamps {
+	return timestamps{
+		nostr.Timestamp(binary.LittleEndian.Uint32(v[0:])),
+		nostr.Timestamp(binary.LittleEndian.Uint32(v[4:])),
+		nostr.Timestamp(binary.LittleEndian.Uint32(v[8:])),
+		nostr.Timestamp(binary.LittleEndian.Uint32(v[12:])),
+	}
+}