Don't hold memory used for sending indexes forever

model/model.go

@@ -563,81 +563,84 @@ func (m *Model) AddConnection(rawConn io.Closer, protoConn protocol.Connection)
 func sendIndexes(conn protocol.Connection, repo string, fs *files.Set) {
 	nodeID := conn.ID()
 	name := conn.Name()
+	var err error
 
 	if debug {
 		l.Debugf("sendIndexes for %s-%s@/%q starting", nodeID, name, repo)
 	}
 
-	initial := true
-	minLocalVer := uint64(0)
-	var err error
-
 	defer func() {
 		if debug {
 			l.Debugf("sendIndexes for %s-%s@/%q exiting: %v", nodeID, name, repo, err)
 		}
 	}()
 
+	minLocalVer, err := sendIndexTo(true, 0, conn, repo, fs)
+
 	for err == nil {
-		if !initial {
-			time.Sleep(5 * time.Second)
-			if fs.LocalVersion(protocol.LocalNodeID) <= minLocalVer {
-				continue
-			}
+		time.Sleep(5 * time.Second)
+		if fs.LocalVersion(protocol.LocalNodeID) <= minLocalVer {
+			continue
 		}
 
-		batch := make([]protocol.FileInfo, 0, indexBatchSize)
-		maxLocalVer := uint64(0)
+		minLocalVer, err = sendIndexTo(false, minLocalVer, conn, repo, fs)
+	}
+}
 
-		fs.WithHave(protocol.LocalNodeID, func(f protocol.FileInfo) bool {
-			if f.LocalVersion <= minLocalVer {
-				return true
-			}
+func sendIndexTo(initial bool, minLocalVer uint64, conn protocol.Connection, repo string, fs *files.Set) (uint64, error) {
+	nodeID := conn.ID()
+	name := conn.Name()
+	batch := make([]protocol.FileInfo, 0, indexBatchSize)
+	maxLocalVer := uint64(0)
+	var err error
 
-			if f.LocalVersion > maxLocalVer {
-				maxLocalVer = f.LocalVersion
-			}
+	fs.WithHave(protocol.LocalNodeID, func(f protocol.FileInfo) bool {
+		if f.LocalVersion <= minLocalVer {
+			return true
+		}
 
-			if len(batch) == indexBatchSize {
-				if initial {
-					if err = conn.Index(repo, batch); err != nil {
-						return false
-					}
-					if debug {
-						l.Debugf("sendIndexes for %s-%s/%q: %d files (initial index)", nodeID, name, repo, len(batch))
-					}
-					initial = false
-				} else {
-					if err = conn.IndexUpdate(repo, batch); err != nil {
-						return false
-					}
-					if debug {
-						l.Debugf("sendIndexes for %s-%s/%q: %d files (batched update)", nodeID, name, repo, len(batch))
-					}
-				}
+		if f.LocalVersion > maxLocalVer {
+			maxLocalVer = f.LocalVersion
+		}
 
-				batch = make([]protocol.FileInfo, 0, indexBatchSize)
+		if len(batch) == indexBatchSize {
+			if initial {
+				if err = conn.Index(repo, batch); err != nil {
+					return false
+				}
+				if debug {
+					l.Debugf("sendIndexes for %s-%s/%q: %d files (initial index)", nodeID, name, repo, len(batch))
+				}
+				initial = false
+			} else {
+				if err = conn.IndexUpdate(repo, batch); err != nil {
+					return false
+				}
+				if debug {
+					l.Debugf("sendIndexes for %s-%s/%q: %d files (batched update)", nodeID, name, repo, len(batch))
+				}
 			}
 
-			batch = append(batch, f)
-			return true
-		})
-
-		if initial {
-			err = conn.Index(repo, batch)
-			if debug && err == nil {
-				l.Debugf("sendIndexes for %s-%s/%q: %d files (small initial index)", nodeID, name, repo, len(batch))
-			}
-			initial = false
-		} else if len(batch) > 0 {
-			err = conn.IndexUpdate(repo, batch)
-			if debug && err == nil {
-				l.Debugf("sendIndexes for %s-%s/%q: %d files (last batch)", nodeID, name, repo, len(batch))
-			}
+			batch = make([]protocol.FileInfo, 0, indexBatchSize)
 		}
 
-		minLocalVer = maxLocalVer
+		batch = append(batch, f)
+		return true
+	})
+
+	if initial && err == nil {
+		err = conn.Index(repo, batch)
+		if debug && err == nil {
+			l.Debugf("sendIndexes for %s-%s/%q: %d files (small initial index)", nodeID, name, repo, len(batch))
+		}
+	} else if len(batch) > 0 && err == nil {
+		err = conn.IndexUpdate(repo, batch)
+		if debug && err == nil {
+			l.Debugf("sendIndexes for %s-%s/%q: %d files (last batch)", nodeID, name, repo, len(batch))
+		}
 	}
+
+	return maxLocalVer, err
 }
 
 func (m *Model) updateLocal(repo string, f protocol.FileInfo) {