restic/restorer.go

102 lines
2.1 KiB
Go

package khepri
import (
"errors"
"fmt"
"os"
"path/filepath"
"github.com/fd0/khepri/backend"
"github.com/juju/arrar"
)
type Restorer struct {
be backend.Server
key *Key
ch *ContentHandler
sn *Snapshot
Error func(dir string, node *Node, err error) error
Filter func(item string, node *Node) bool
}
// NewRestorer creates a restorer preloaded with the content from the snapshot snid.
func NewRestorer(be backend.Server, key *Key, snid backend.ID) (*Restorer, error) {
r := &Restorer{
be: be,
key: key,
}
var err error
r.ch, err = NewContentHandler(be, key)
if err != nil {
return nil, arrar.Annotate(err, "create contenthandler for restorer")
}
r.sn, err = r.ch.LoadSnapshot(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 }
// allow all files
r.Filter = func(string, *Node) bool { return true }
return r, nil
}
func (res *Restorer) to(dir string, tree_id backend.ID) error {
tree := Tree{}
err := res.ch.LoadJSON(backend.Tree, tree_id, &tree)
if err != nil {
return res.Error(dir, nil, arrar.Annotate(err, "LoadJSON"))
}
for _, node := range tree {
p := filepath.Join(dir, node.Name)
if !res.Filter(p, node) {
continue
}
err := node.CreateAt(res.ch, p)
if err != nil {
err = res.Error(p, 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", tree_id))
}
err = res.to(p, node.Subtree)
if err != nil {
err = res.Error(p, 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 {
err := os.MkdirAll(dir, 0700)
if err != nil && err != os.ErrExist {
return err
}
return res.to(dir, res.sn.Content)
}
func (res *Restorer) Snapshot() *Snapshot {
return res.sn
}