feat: Waku v2 bridge

Issue #12610

vendor/github.com/status-im/status-go/mailserver/mailserver_db.go

@@ -0,0 +1,42 @@
+package mailserver
+
+import (
+	"time"
+
+	"github.com/status-im/status-go/eth-node/types"
+)
+
+// every this many seconds check real envelopes count
+const envelopeCountCheckInterval = 60
+
+// DB is an interface to abstract interactions with the db so that the mailserver
+// is agnostic to the underlying technology used
+type DB interface {
+	Close() error
+	// SaveEnvelope stores an envelope
+	SaveEnvelope(types.Envelope) error
+	// GetEnvelope returns an rlp encoded envelope from the datastore
+	GetEnvelope(*DBKey) ([]byte, error)
+	// Prune removes envelopes older than time
+	Prune(time.Time, int) (int, error)
+	// BuildIterator returns an iterator over envelopes
+	BuildIterator(query CursorQuery) (Iterator, error)
+}
+
+type Iterator interface {
+	Next() bool
+	DBKey() (*DBKey, error)
+	Release() error
+	Error() error
+	GetEnvelopeByBloomFilter(bloom []byte) ([]byte, error)
+	GetEnvelopeByTopicsMap(topics map[types.TopicType]bool) ([]byte, error)
+}
+
+type CursorQuery struct {
+	start  []byte
+	end    []byte
+	cursor []byte
+	limit  uint32
+	bloom  []byte
+	topics [][]byte
+}