rewrite: extract tree filtering

internal/walker/rewriter.go

@@ -0,0 +1,72 @@
+package walker
+
+import (
+	"context"
+	"path"
+
+	"github.com/restic/restic/internal/debug"
+	"github.com/restic/restic/internal/restic"
+)
+
+type RejectByNameFunc func(path string) bool
+
+type TreeFilterVisitor struct {
+	CheckExclude RejectByNameFunc
+	PrintExclude func(string)
+}
+
+func FilterTree(ctx context.Context, repo restic.Repository, nodepath string, nodeID restic.ID, visitor *TreeFilterVisitor) (newNodeID restic.ID, err error) {
+	curTree, err := restic.LoadTree(ctx, repo, nodeID)
+	if err != nil {
+		return restic.ID{}, err
+	}
+
+	debug.Log("filterTree: %s, nodeId: %s\n", nodepath, nodeID.Str())
+
+	changed := false
+	tb := restic.NewTreeJSONBuilder()
+	for _, node := range curTree.Nodes {
+		path := path.Join(nodepath, node.Name)
+		if visitor.CheckExclude(path) {
+			if visitor.PrintExclude != nil {
+				visitor.PrintExclude(path)
+			}
+			changed = true
+			continue
+		}
+
+		if node.Subtree == nil {
+			err = tb.AddNode(node)
+			if err != nil {
+				return restic.ID{}, err
+			}
+			continue
+		}
+		newID, err := FilterTree(ctx, repo, path, *node.Subtree, visitor)
+		if err != nil {
+			return restic.ID{}, err
+		}
+		if !node.Subtree.Equal(newID) {
+			changed = true
+		}
+		node.Subtree = &newID
+		err = tb.AddNode(node)
+		if err != nil {
+			return restic.ID{}, err
+		}
+	}
+
+	if changed {
+		tree, err := tb.Finalize()
+		if err != nil {
+			return restic.ID{}, err
+		}
+
+		// Save new tree
+		newTreeID, _, _, err := repo.SaveBlob(ctx, restic.TreeBlob, tree, restic.ID{}, false)
+		debug.Log("filterTree: save new tree for %s as %v\n", nodepath, newTreeID)
+		return newTreeID, err
+	}
+
+	return nodeID, nil
+}