feat: binary search for first version if legacy pruning is broken

Author: PaddyMc

nodedb.go

@@ -709,7 +709,14 @@ func (ndb *nodeDB) deleteVersionsTo(toVersion int64) error {
 		if err := ndb.deleteLegacyVersions(legacyLatestVersion); err != nil {
 			ndb.logger.Error("Error deleting legacy versions", "err", err)
 		}
-		first = legacyLatestVersion + 1
+		// NOTE: When pruning is broken for legacy versions we need to find the
+		// latest non legacy version in the store
+		// TODO: Make sure legacy pruning works as expected and does not fail
+		firstNonLegacyVersion, err := ndb.getFirstNonLegacyVersion()
+		if err != nil {
+			return err
+		}
+		first = firstNonLegacyVersion
 
 		// reset the legacy latest version forcibly to avoid multiple calls
 		ndb.resetLegacyLatestVersion(-1)
@@ -752,6 +759,35 @@ func (ndb *nodeDB) legacyRootKey(version int64) []byte {
 	return legacyRootKeyFormat.Key(version)
 }
 
+// getFirstNonLegacyVersion binary searches the store for the first non-legacy version
+func (ndb *nodeDB) getFirstNonLegacyVersion() (int64, error) {
+	ndb.mtx.Lock()
+	firstVersion := ndb.firstVersion
+	ndb.mtx.Unlock()
+
+	// Find the first version
+	latestVersion, err := ndb.getLatestVersion()
+	if err != nil {
+		return 0, err
+	}
+	for firstVersion < latestVersion {
+		version := (latestVersion + firstVersion) >> 1
+		has, err := ndb.hasVersion(version)
+		if err != nil {
+			return 0, err
+		}
+		if has {
+			latestVersion = version
+		} else {
+			firstVersion = version + 1
+		}
+	}
+
+	ndb.resetFirstVersion(latestVersion)
+
+	return latestVersion, nil
+}
+
 func (ndb *nodeDB) getFirstVersion() (int64, error) {
 	ndb.mtx.Lock()
 	firstVersion := ndb.firstVersion