restic/internal/repository/raw.go
2024-05-18 21:28:54 +02:00

56 lines
1.6 KiB
Go

package repository
import (
"bytes"
"context"
"fmt"
"io"
"github.com/restic/restic/internal/backend"
"github.com/restic/restic/internal/restic"
)
// LoadRaw reads all data stored in the backend for the file with id and filetype t.
// If the backend returns data that does not match the id, then the buffer is returned
// along with an error that is a restic.ErrInvalidData error.
func (r *Repository) LoadRaw(ctx context.Context, t restic.FileType, id restic.ID) (buf []byte, err error) {
h := backend.Handle{Type: t, Name: id.String()}
buf, err = loadRaw(ctx, r.be, h)
// retry loading damaged data only once. If a file fails to download correctly
// the second time, then it is likely corrupted at the backend.
if h.Type != backend.ConfigFile && id != restic.Hash(buf) {
if r.Cache != nil {
// Cleanup cache to make sure it's not the cached copy that is broken.
// Ignore error as there's not much we can do in that case.
_ = r.Cache.Forget(h)
}
buf, err = loadRaw(ctx, r.be, h)
if err == nil && id != restic.Hash(buf) {
// Return corrupted data to the caller if it is still broken the second time to
// let the caller decide what to do with the data.
return buf, fmt.Errorf("LoadRaw(%v): %w", h, restic.ErrInvalidData)
}
}
if err != nil {
return nil, err
}
return buf, nil
}
func loadRaw(ctx context.Context, be backend.Backend, h backend.Handle) (buf []byte, err error) {
err = be.Load(ctx, h, 0, 0, func(rd io.Reader) error {
wr := new(bytes.Buffer)
_, cerr := io.Copy(wr, rd)
if cerr != nil {
return cerr
}
buf = wr.Bytes()
return cerr
})
return buf, err
}