Initial commit

vendor/github.com/cockroachdb/pebble/internal/rangedel/rangedel.go

@@ -0,0 +1,43 @@
+// Copyright 2022 The LevelDB-Go and Pebble Authors. All rights reserved. Use
+// of this source code is governed by a BSD-style license that can be found in
+// the LICENSE file.
+
+package rangedel
+
+import (
+	"github.com/cockroachdb/pebble/internal/base"
+	"github.com/cockroachdb/pebble/internal/keyspan"
+)
+
+// Encode takes a Span containing only range deletions. It invokes the provided
+// closure with the encoded internal keys that represent the Span's state. The
+// keys and values passed to emit are only valid until the closure returns.  If
+// emit returns an error, Encode stops and returns the error.
+func Encode(s *keyspan.Span, emit func(k base.InternalKey, v []byte) error) error {
+	for _, k := range s.Keys {
+		if k.Kind() != base.InternalKeyKindRangeDelete {
+			return base.CorruptionErrorf("pebble: rangedel.Encode cannot encode %s key", k.Kind())
+		}
+		ik := base.InternalKey{
+			UserKey: s.Start,
+			Trailer: k.Trailer,
+		}
+		if err := emit(ik, s.End); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Decode takes an internal key pair encoding a range deletion and returns a
+// decoded keyspan containing the key. If keysDst is provided, the key will be
+// appended to keysDst, avoiding an allocation.
+func Decode(ik base.InternalKey, v []byte, keysDst []keyspan.Key) keyspan.Span {
+	return keyspan.Span{
+		Start: ik.UserKey,
+		End:   v,
+		Keys: append(keysDst, keyspan.Key{
+			Trailer: ik.Trailer,
+		}),
+	}
+}