mirror of
https://github.com/octoleo/restic.git
synced 2024-11-30 00:33:57 +00:00
374 lines
8.8 KiB
Go
374 lines
8.8 KiB
Go
package local
|
|
|
|
import (
|
|
"context"
|
|
"hash"
|
|
"io"
|
|
"io/ioutil"
|
|
"os"
|
|
"path/filepath"
|
|
"syscall"
|
|
|
|
"github.com/restic/restic/internal/errors"
|
|
"github.com/restic/restic/internal/restic"
|
|
|
|
"github.com/restic/restic/internal/backend"
|
|
"github.com/restic/restic/internal/debug"
|
|
"github.com/restic/restic/internal/fs"
|
|
|
|
"github.com/cenkalti/backoff/v4"
|
|
)
|
|
|
|
// Local is a backend in a local directory.
|
|
type Local struct {
|
|
Config
|
|
backend.Layout
|
|
}
|
|
|
|
// ensure statically that *Local implements restic.Backend.
|
|
var _ restic.Backend = &Local{}
|
|
|
|
const defaultLayout = "default"
|
|
|
|
// Open opens the local backend as specified by config.
|
|
func Open(ctx context.Context, cfg Config) (*Local, error) {
|
|
debug.Log("open local backend at %v (layout %q)", cfg.Path, cfg.Layout)
|
|
l, err := backend.ParseLayout(ctx, &backend.LocalFilesystem{}, cfg.Layout, defaultLayout, cfg.Path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &Local{Config: cfg, Layout: l}, nil
|
|
}
|
|
|
|
// Create creates all the necessary files and directories for a new local
|
|
// backend at dir. Afterwards a new config blob should be created.
|
|
func Create(ctx context.Context, cfg Config) (*Local, error) {
|
|
debug.Log("create local backend at %v (layout %q)", cfg.Path, cfg.Layout)
|
|
|
|
l, err := backend.ParseLayout(ctx, &backend.LocalFilesystem{}, cfg.Layout, defaultLayout, cfg.Path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
be := &Local{
|
|
Config: cfg,
|
|
Layout: l,
|
|
}
|
|
|
|
// test if config file already exists
|
|
_, err = fs.Lstat(be.Filename(restic.Handle{Type: restic.ConfigFile}))
|
|
if err == nil {
|
|
return nil, errors.New("config file already exists")
|
|
}
|
|
|
|
// create paths for data and refs
|
|
for _, d := range be.Paths() {
|
|
err := fs.MkdirAll(d, backend.Modes.Dir)
|
|
if err != nil {
|
|
return nil, errors.WithStack(err)
|
|
}
|
|
}
|
|
|
|
return be, nil
|
|
}
|
|
|
|
// Location returns this backend's location (the directory name).
|
|
func (b *Local) Location() string {
|
|
return b.Path
|
|
}
|
|
|
|
// Hasher may return a hash function for calculating a content hash for the backend
|
|
func (b *Local) Hasher() hash.Hash {
|
|
return nil
|
|
}
|
|
|
|
// IsNotExist returns true if the error is caused by a non existing file.
|
|
func (b *Local) IsNotExist(err error) bool {
|
|
return errors.Is(err, os.ErrNotExist)
|
|
}
|
|
|
|
// Save stores data in the backend at the handle.
|
|
func (b *Local) Save(ctx context.Context, h restic.Handle, rd restic.RewindReader) (err error) {
|
|
debug.Log("Save %v", h)
|
|
if err := h.Valid(); err != nil {
|
|
return backoff.Permanent(err)
|
|
}
|
|
|
|
finalname := b.Filename(h)
|
|
dir := filepath.Dir(finalname)
|
|
|
|
defer func() {
|
|
// Mark non-retriable errors as such
|
|
if errors.Is(err, syscall.ENOSPC) || os.IsPermission(err) {
|
|
err = backoff.Permanent(err)
|
|
}
|
|
}()
|
|
|
|
// Create new file with a temporary name.
|
|
tmpname := filepath.Base(finalname) + "-tmp-"
|
|
f, err := tempFile(dir, tmpname)
|
|
|
|
if b.IsNotExist(err) {
|
|
debug.Log("error %v: creating dir", err)
|
|
|
|
// error is caused by a missing directory, try to create it
|
|
mkdirErr := fs.MkdirAll(dir, backend.Modes.Dir)
|
|
if mkdirErr != nil {
|
|
debug.Log("error creating dir %v: %v", dir, mkdirErr)
|
|
} else {
|
|
// try again
|
|
f, err = tempFile(dir, tmpname)
|
|
}
|
|
}
|
|
|
|
if err != nil {
|
|
return errors.WithStack(err)
|
|
}
|
|
|
|
defer func(f *os.File) {
|
|
if err != nil {
|
|
_ = f.Close() // Double Close is harmless.
|
|
// Remove after Rename is harmless: we embed the final name in the
|
|
// temporary's name and no other goroutine will get the same data to
|
|
// Save, so the temporary name should never be reused by another
|
|
// goroutine.
|
|
_ = fs.Remove(f.Name())
|
|
}
|
|
}(f)
|
|
|
|
// save data, then sync
|
|
wbytes, err := io.Copy(f, rd)
|
|
if err != nil {
|
|
return errors.WithStack(err)
|
|
}
|
|
// sanity check
|
|
if wbytes != rd.Length() {
|
|
return errors.Errorf("wrote %d bytes instead of the expected %d bytes", wbytes, rd.Length())
|
|
}
|
|
|
|
// Ignore error if filesystem does not support fsync.
|
|
err = f.Sync()
|
|
syncNotSup := errors.Is(err, syscall.ENOTSUP)
|
|
if err != nil && !syncNotSup {
|
|
return errors.WithStack(err)
|
|
}
|
|
|
|
// Close, then rename. Windows doesn't like the reverse order.
|
|
if err = f.Close(); err != nil {
|
|
return errors.WithStack(err)
|
|
}
|
|
if err = os.Rename(f.Name(), finalname); err != nil {
|
|
return errors.WithStack(err)
|
|
}
|
|
|
|
// Now sync the directory to commit the Rename.
|
|
if !syncNotSup {
|
|
err = fsyncDir(dir)
|
|
if err != nil {
|
|
return errors.WithStack(err)
|
|
}
|
|
}
|
|
|
|
// try to mark file as read-only to avoid accidential modifications
|
|
// ignore if the operation fails as some filesystems don't allow the chmod call
|
|
// e.g. exfat and network file systems with certain mount options
|
|
err = setFileReadonly(finalname, backend.Modes.File)
|
|
if err != nil && !os.IsPermission(err) {
|
|
return errors.WithStack(err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
var tempFile = ioutil.TempFile // Overridden by test.
|
|
|
|
// Load runs fn with a reader that yields the contents of the file at h at the
|
|
// given offset.
|
|
func (b *Local) Load(ctx context.Context, h restic.Handle, length int, offset int64, fn func(rd io.Reader) error) error {
|
|
return backend.DefaultLoad(ctx, h, length, offset, b.openReader, fn)
|
|
}
|
|
|
|
func (b *Local) openReader(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
|
|
debug.Log("Load %v, length %v, offset %v", h, length, offset)
|
|
if err := h.Valid(); err != nil {
|
|
return nil, backoff.Permanent(err)
|
|
}
|
|
|
|
if offset < 0 {
|
|
return nil, errors.New("offset is negative")
|
|
}
|
|
|
|
f, err := fs.Open(b.Filename(h))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if offset > 0 {
|
|
_, err = f.Seek(offset, 0)
|
|
if err != nil {
|
|
_ = f.Close()
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
if length > 0 {
|
|
return backend.LimitReadCloser(f, int64(length)), nil
|
|
}
|
|
|
|
return f, nil
|
|
}
|
|
|
|
// Stat returns information about a blob.
|
|
func (b *Local) Stat(ctx context.Context, h restic.Handle) (restic.FileInfo, error) {
|
|
debug.Log("Stat %v", h)
|
|
if err := h.Valid(); err != nil {
|
|
return restic.FileInfo{}, backoff.Permanent(err)
|
|
}
|
|
|
|
fi, err := fs.Stat(b.Filename(h))
|
|
if err != nil {
|
|
return restic.FileInfo{}, errors.WithStack(err)
|
|
}
|
|
|
|
return restic.FileInfo{Size: fi.Size(), Name: h.Name}, nil
|
|
}
|
|
|
|
// Test returns true if a blob of the given type and name exists in the backend.
|
|
func (b *Local) Test(ctx context.Context, h restic.Handle) (bool, error) {
|
|
debug.Log("Test %v", h)
|
|
_, err := fs.Stat(b.Filename(h))
|
|
if err != nil {
|
|
if b.IsNotExist(err) {
|
|
return false, nil
|
|
}
|
|
return false, errors.WithStack(err)
|
|
}
|
|
|
|
return true, nil
|
|
}
|
|
|
|
// Remove removes the blob with the given name and type.
|
|
func (b *Local) Remove(ctx context.Context, h restic.Handle) error {
|
|
debug.Log("Remove %v", h)
|
|
fn := b.Filename(h)
|
|
|
|
// reset read-only flag
|
|
err := fs.Chmod(fn, 0666)
|
|
if err != nil && !os.IsPermission(err) {
|
|
return errors.WithStack(err)
|
|
}
|
|
|
|
return fs.Remove(fn)
|
|
}
|
|
|
|
// List runs fn for each file in the backend which has the type t. When an
|
|
// error occurs (or fn returns an error), List stops and returns it.
|
|
func (b *Local) List(ctx context.Context, t restic.FileType, fn func(restic.FileInfo) error) (err error) {
|
|
debug.Log("List %v", t)
|
|
|
|
basedir, subdirs := b.Basedir(t)
|
|
if subdirs {
|
|
err = visitDirs(ctx, basedir, fn)
|
|
} else {
|
|
err = visitFiles(ctx, basedir, fn, false)
|
|
}
|
|
|
|
if b.IsNotExist(err) {
|
|
debug.Log("ignoring non-existing directory")
|
|
return nil
|
|
}
|
|
|
|
return err
|
|
}
|
|
|
|
// The following two functions are like filepath.Walk, but visit only one or
|
|
// two levels of directory structure (including dir itself as the first level).
|
|
// Also, visitDirs assumes it sees a directory full of directories, while
|
|
// visitFiles wants a directory full or regular files.
|
|
func visitDirs(ctx context.Context, dir string, fn func(restic.FileInfo) error) error {
|
|
d, err := fs.Open(dir)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
sub, err := d.Readdirnames(-1)
|
|
if err != nil {
|
|
// ignore subsequent errors
|
|
_ = d.Close()
|
|
return err
|
|
}
|
|
|
|
err = d.Close()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
for _, f := range sub {
|
|
err = visitFiles(ctx, filepath.Join(dir, f), fn, true)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return ctx.Err()
|
|
}
|
|
|
|
func visitFiles(ctx context.Context, dir string, fn func(restic.FileInfo) error, ignoreNotADirectory bool) error {
|
|
d, err := fs.Open(dir)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if ignoreNotADirectory {
|
|
fi, err := d.Stat()
|
|
if err != nil || !fi.IsDir() {
|
|
// ignore subsequent errors
|
|
_ = d.Close()
|
|
return err
|
|
}
|
|
}
|
|
|
|
sub, err := d.Readdir(-1)
|
|
if err != nil {
|
|
// ignore subsequent errors
|
|
_ = d.Close()
|
|
return err
|
|
}
|
|
|
|
err = d.Close()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
for _, fi := range sub {
|
|
select {
|
|
case <-ctx.Done():
|
|
return ctx.Err()
|
|
default:
|
|
}
|
|
|
|
err := fn(restic.FileInfo{
|
|
Name: fi.Name(),
|
|
Size: fi.Size(),
|
|
})
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Delete removes the repository and all files.
|
|
func (b *Local) Delete(ctx context.Context) error {
|
|
debug.Log("Delete()")
|
|
return fs.RemoveAll(b.Path)
|
|
}
|
|
|
|
// Close closes all open files.
|
|
func (b *Local) Close() error {
|
|
debug.Log("Close()")
|
|
// this does not need to do anything, all open files are closed within the
|
|
// same function.
|
|
return nil
|
|
}
|