get rid of badger everywhere, including as an sdk/hints backend.

sdk/kvstore/bbolt/store.go

@@ -0,0 +1,96 @@
+package bbolt
+
+import (
+	"fiatjaf.com/nostr/sdk/kvstore"
+	"go.etcd.io/bbolt"
+)
+
+var _ kvstore.KVStore = (*Store)(nil)
+
+var (
+	defaultBucket = []byte("default")
+)
+
+type Store struct {
+	db     *bbolt.DB
+	bucket []byte
+}
+
+func NewStore(path string) (*Store, error) {
+	db, err := bbolt.Open(path, 0600, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create the default bucket
+	err = db.Update(func(tx *bbolt.Tx) error {
+		_, err := tx.CreateBucketIfNotExists(defaultBucket)
+		return err
+	})
+	if err != nil {
+		db.Close()
+		return nil, err
+	}
+
+	return &Store{db: db, bucket: defaultBucket}, nil
+}
+
+func (s *Store) Get(key []byte) ([]byte, error) {
+	var val []byte
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(s.bucket)
+		if b == nil {
+			return nil
+		}
+		val = b.Get(key)
+		if val != nil {
+			// Make a copy since bbolt reuses the slice
+			valCopy := make([]byte, len(val))
+			copy(valCopy, val)
+			val = valCopy
+		}
+		return nil
+	})
+	return val, err
+}
+
+func (s *Store) Set(key []byte, value []byte) error {
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(s.bucket)
+		return b.Put(key, value)
+	})
+}
+
+func (s *Store) Delete(key []byte) error {
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(s.bucket)
+		return b.Delete(key)
+	})
+}
+
+func (s *Store) Close() error {
+	return s.db.Close()
+}
+
+func (s *Store) Update(key []byte, f func([]byte) ([]byte, error)) error {
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(s.bucket)
+		var val []byte
+		if v := b.Get(key); v != nil {
+			val = make([]byte, len(v))
+			copy(val, v)
+		}
+
+		newVal, err := f(val)
+		if err == kvstore.NoOp {
+			return nil
+		} else if err != nil {
+			return err
+		}
+
+		if newVal == nil {
+			return b.Delete(key)
+		}
+		return b.Put(key, newVal)
+	})
+}