bring in khatru and eventstore.

eventstore/badger/save.go

@@ -0,0 +1,59 @@
+package badger
+
+import (
+	"context"
+	"encoding/hex"
+	"fmt"
+	"math"
+
+	"github.com/dgraph-io/badger/v4"
+	"github.com/fiatjaf/eventstore"
+	bin "github.com/fiatjaf/eventstore/internal/binary"
+	"github.com/nbd-wtf/go-nostr"
+)
+
+func (b *BadgerBackend) SaveEvent(ctx context.Context, evt *nostr.Event) error {
+	// sanity checking
+	if evt.CreatedAt > math.MaxUint32 || evt.Kind > math.MaxUint16 {
+		return fmt.Errorf("event with values out of expected boundaries")
+	}
+
+	return b.Update(func(txn *badger.Txn) error {
+		// query event by id to ensure we don't save duplicates
+		id, _ := hex.DecodeString(evt.ID)
+		prefix := make([]byte, 1+8)
+		prefix[0] = indexIdPrefix
+		copy(prefix[1:], id)
+		it := txn.NewIterator(badger.IteratorOptions{})
+		defer it.Close()
+		it.Seek(prefix)
+		if it.ValidForPrefix(prefix) {
+			// event exists
+			return eventstore.ErrDupEvent
+		}
+
+		return b.save(txn, evt)
+	})
+}
+
+func (b *BadgerBackend) save(txn *badger.Txn, evt *nostr.Event) error {
+	// encode to binary
+	bin, err := bin.Marshal(evt)
+	if err != nil {
+		return err
+	}
+
+	idx := b.Serial()
+	// raw event store
+	if err := txn.Set(idx, bin); err != nil {
+		return err
+	}
+
+	for k := range b.getIndexKeysForEvent(evt, idx[1:]) {
+		if err := txn.Set(k, nil); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}