restic/restorer.go

113 lines
2.6 KiB
Go

package restic
import (
"errors"
"fmt"
"os"
"path/filepath"
"syscall"
"github.com/juju/arrar"
"github.com/restic/restic/backend"
"github.com/restic/restic/server"
)
type Restorer struct {
s *server.Server
sn *Snapshot
Error func(dir string, node *Node, err error) error
Filter func(item string, dstpath string, node *Node) bool
}
// NewRestorer creates a restorer preloaded with the content from the snapshot snid.
func NewRestorer(s *server.Server, snid backend.ID) (*Restorer, error) {
r := &Restorer{s: s}
var err error
r.sn, err = LoadSnapshot(s, snid)
if err != nil {
return nil, arrar.Annotate(err, "load snapshot for restorer")
}
// abort on all errors
r.Error = func(string, *Node, error) error { return err }
return r, nil
}
func (res *Restorer) to(dst string, dir string, treeBlob server.Blob) error {
tree, err := LoadTree(res.s, treeBlob)
if err != nil {
return res.Error(dir, nil, arrar.Annotate(err, "LoadTree"))
}
for _, node := range tree.Nodes {
dstpath := filepath.Join(dst, dir, node.Name)
if res.Filter == nil ||
res.Filter(filepath.Join(dir, node.Name), dstpath, node) {
err := CreateNodeAt(node, tree.Map, res.s, dstpath)
// Did it fail because of ENOENT?
if arrar.Check(err, func(err error) bool {
if pe, ok := err.(*os.PathError); ok {
errn, ok := pe.Err.(syscall.Errno)
return ok && errn == syscall.ENOENT
}
return false
}) {
// Create parent directories and retry
err = os.MkdirAll(filepath.Dir(dstpath), 0700)
if err == nil || err == os.ErrExist {
err = CreateNodeAt(node, tree.Map, res.s, dstpath)
}
}
if err != nil {
err = res.Error(dstpath, node, arrar.Annotate(err, "create node"))
if err != nil {
return err
}
}
}
if node.Type == "dir" {
if node.Subtree == nil {
return errors.New(fmt.Sprintf("Dir without subtree in tree %s", treeBlob))
}
subp := filepath.Join(dir, node.Name)
subtreeBlob, err := tree.Map.FindID(node.Subtree)
if err != nil {
err = res.Error(subp, node, arrar.Annotate(err, "lookup subtree"))
if err != nil {
return err
}
}
err = res.to(dst, subp, subtreeBlob)
if err != nil {
err = res.Error(subp, node, arrar.Annotate(err, "restore subtree"))
if err != nil {
return err
}
}
}
}
return nil
}
// RestoreTo creates the directories and files in the snapshot below dir.
// Before an item is created, res.Filter is called.
func (res *Restorer) RestoreTo(dir string) error {
return res.to(dir, "", res.sn.Tree)
}
func (res *Restorer) Snapshot() *Snapshot {
return res.sn
}