dump: Split tar and walk logic

internal/dump/common.go

@@ -0,0 +1,104 @@
+package dump
+
+import (
+	"context"
+	"io"
+	"path"
+
+	"github.com/restic/restic/internal/errors"
+	"github.com/restic/restic/internal/restic"
+	"github.com/restic/restic/internal/walker"
+)
+
+// dumper implements saving node data.
+type dumper interface {
+	dumpNode(ctx context.Context, node *restic.Node, repo restic.Repository) error
+}
+
+// WriteDump will write the contents of the given tree to the given destination.
+// It will loop over all nodes in the tree and dump them recursively.
+type WriteDump func(ctx context.Context, repo restic.Repository, tree *restic.Tree, rootPath string, dst io.Writer) error
+
+func writeDump(ctx context.Context, repo restic.Repository, tree *restic.Tree, rootPath string, dmp dumper, dst io.Writer) error {
+	for _, rootNode := range tree.Nodes {
+		rootNode.Path = rootPath
+		err := dumpTree(ctx, repo, rootNode, rootPath, dmp)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func dumpTree(ctx context.Context, repo restic.Repository, rootNode *restic.Node, rootPath string, dmp dumper) error {
+	rootNode.Path = path.Join(rootNode.Path, rootNode.Name)
+	rootPath = rootNode.Path
+
+	if err := dmp.dumpNode(ctx, rootNode, repo); err != nil {
+		return err
+	}
+
+	// If this is no directory we are finished
+	if !IsDir(rootNode) {
+		return nil
+	}
+
+	err := walker.Walk(ctx, repo, *rootNode.Subtree, nil, func(_ restic.ID, nodepath string, node *restic.Node, err error) (bool, error) {
+		if err != nil {
+			return false, err
+		}
+		if node == nil {
+			return false, nil
+		}
+
+		node.Path = path.Join(rootPath, nodepath)
+
+		if IsFile(node) || IsLink(node) || IsDir(node) {
+			err := dmp.dumpNode(ctx, node, repo)
+			if err != nil {
+				return false, err
+			}
+		}
+
+		return false, nil
+	})
+
+	return err
+}
+
+// GetNodeData will write the contents of the node to the given output.
+func GetNodeData(ctx context.Context, output io.Writer, repo restic.Repository, node *restic.Node) error {
+	var (
+		buf []byte
+		err error
+	)
+	for _, id := range node.Content {
+		buf, err = repo.LoadBlob(ctx, restic.DataBlob, id, buf)
+		if err != nil {
+			return err
+		}
+
+		_, err = output.Write(buf)
+		if 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"
+}