package dump import ( "context" "io" "path" "github.com/restic/restic/internal/bloblru" "github.com/restic/restic/internal/errors" "github.com/restic/restic/internal/restic" "github.com/restic/restic/internal/walker" ) // A Dumper writes trees and files from a repository to a Writer // in an archive format. type Dumper struct { cache *bloblru.Cache format string repo restic.BlobLoader w io.Writer } func New(format string, repo restic.BlobLoader, w io.Writer) *Dumper { return &Dumper{ cache: bloblru.New(64 << 20), format: format, repo: repo, w: w, } } func (d *Dumper) DumpTree(ctx context.Context, tree *restic.Tree, rootPath string) error { ctx, cancel := context.WithCancel(ctx) defer cancel() // ch is buffered to deal with variable download/write speeds. ch := make(chan *restic.Node, 10) go sendTrees(ctx, d.repo, tree, rootPath, ch) switch d.format { case "tar": return d.dumpTar(ctx, ch) case "zip": return d.dumpZip(ctx, ch) default: panic("unknown dump format") } } func sendTrees(ctx context.Context, repo restic.BlobLoader, tree *restic.Tree, rootPath string, ch chan *restic.Node) { defer close(ch) for _, root := range tree.Nodes { root.Path = path.Join(rootPath, root.Name) if sendNodes(ctx, repo, root, ch) != nil { break } } } func sendNodes(ctx context.Context, repo restic.BlobLoader, root *restic.Node, ch chan *restic.Node) error { select { case ch <- root: case <-ctx.Done(): return ctx.Err() } // If this is no directory we are finished if !IsDir(root) { return nil } err := walker.Walk(ctx, repo, *root.Subtree, walker.WalkVisitor{ProcessNode: func(_ restic.ID, nodepath string, node *restic.Node, err error) error { if err != nil { return err } if node == nil { return nil } node.Path = path.Join(root.Path, nodepath) if !IsFile(node) && !IsDir(node) && !IsLink(node) { return nil } select { case ch <- node: case <-ctx.Done(): return ctx.Err() } return nil }}) return err } // WriteNode writes a file node's contents directly to d's Writer, // without caring about d's format. func (d *Dumper) WriteNode(ctx context.Context, node *restic.Node) error { return d.writeNode(ctx, d.w, node) } func (d *Dumper) writeNode(ctx context.Context, w io.Writer, node *restic.Node) error { var ( buf []byte err error ) for _, id := range node.Content { blob, ok := d.cache.Get(id) if !ok { blob, err = d.repo.LoadBlob(ctx, restic.DataBlob, id, buf) if err != nil { return err } buf = d.cache.Add(id, blob) // Reuse evicted buffer. } if _, err := w.Write(blob); err != nil { return errors.Wrap(err, "Write") } } return nil } // IsDir checks if the given node is a directory. func IsDir(node *restic.Node) bool { return node.Type == "dir" } // IsLink checks if the given node as a link. func IsLink(node *restic.Node) bool { return node.Type == "symlink" } // IsFile checks if the given node is a file. func IsFile(node *restic.Node) bool { return node.Type == "file" }