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mirror of https://github.com/octoleo/restic.git synced 2024-12-29 13:22:43 +00:00
restic/internal/mock/backend.go
Alexander Neumann 99f7fd74e3 backend: Improve Save()
As mentioned in issue [#1560](https://github.com/restic/restic/pull/1560#issuecomment-364689346)
this changes the signature for `backend.Save()`. It now takes a
parameter of interface type `RewindReader`, so that the backend
implementations or our `RetryBackend` middleware can reset the reader to
the beginning and then retry an upload operation.

The `RewindReader` interface also provides a `Length()` method, which is
used in the backend to get the size of the data to be saved. This
removes several ugly hacks we had to do to pull the size back out of the
`io.Reader` passed to `Save()` before. In the `s3` and `rest` backend
this is actively used.
2018-03-03 15:49:44 +01:00

137 lines
3.3 KiB
Go

package mock
import (
"context"
"io"
"github.com/restic/restic/internal/errors"
"github.com/restic/restic/internal/restic"
)
// Backend implements a mock backend.
type Backend struct {
CloseFn func() error
IsNotExistFn func(err error) bool
SaveFn func(ctx context.Context, h restic.Handle, rd restic.RewindReader) error
OpenReaderFn func(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error)
StatFn func(ctx context.Context, h restic.Handle) (restic.FileInfo, error)
ListFn func(ctx context.Context, t restic.FileType, fn func(restic.FileInfo) error) error
RemoveFn func(ctx context.Context, h restic.Handle) error
TestFn func(ctx context.Context, h restic.Handle) (bool, error)
DeleteFn func(ctx context.Context) error
LocationFn func() string
}
// NewBackend returns new mock Backend instance
func NewBackend() *Backend {
be := &Backend{}
return be
}
// Close the backend.
func (m *Backend) Close() error {
if m.CloseFn == nil {
return nil
}
return m.CloseFn()
}
// Location returns a location string.
func (m *Backend) Location() string {
if m.LocationFn == nil {
return ""
}
return m.LocationFn()
}
// IsNotExist returns true if the error is caused by a missing file.
func (m *Backend) IsNotExist(err error) bool {
if m.IsNotExistFn == nil {
return false
}
return m.IsNotExistFn(err)
}
// Save data in the backend.
func (m *Backend) Save(ctx context.Context, h restic.Handle, rd restic.RewindReader) error {
if m.SaveFn == nil {
return errors.New("not implemented")
}
return m.SaveFn(ctx, h, rd)
}
// Load runs fn with a reader that yields the contents of the file at h at the
// given offset.
func (m *Backend) Load(ctx context.Context, h restic.Handle, length int, offset int64, fn func(rd io.Reader) error) error {
rd, err := m.openReader(ctx, h, length, offset)
if err != nil {
return err
}
err = fn(rd)
if err != nil {
rd.Close() // ignore secondary errors closing the reader
return err
}
return rd.Close()
}
func (m *Backend) openReader(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) {
if m.OpenReaderFn == nil {
return nil, errors.New("not implemented")
}
return m.OpenReaderFn(ctx, h, length, offset)
}
// Stat an object in the backend.
func (m *Backend) Stat(ctx context.Context, h restic.Handle) (restic.FileInfo, error) {
if m.StatFn == nil {
return restic.FileInfo{}, errors.New("not implemented")
}
return m.StatFn(ctx, h)
}
// List items of type t.
func (m *Backend) List(ctx context.Context, t restic.FileType, fn func(restic.FileInfo) error) error {
if m.ListFn == nil {
return nil
}
return m.ListFn(ctx, t, fn)
}
// Remove data from the backend.
func (m *Backend) Remove(ctx context.Context, h restic.Handle) error {
if m.RemoveFn == nil {
return errors.New("not implemented")
}
return m.RemoveFn(ctx, h)
}
// Test for the existence of a specific item.
func (m *Backend) Test(ctx context.Context, h restic.Handle) (bool, error) {
if m.TestFn == nil {
return false, errors.New("not implemented")
}
return m.TestFn(ctx, h)
}
// Delete all data.
func (m *Backend) Delete(ctx context.Context) error {
if m.DeleteFn == nil {
return errors.New("not implemented")
}
return m.DeleteFn(ctx)
}
// Make sure that Backend implements the backend interface.
var _ restic.Backend = &Backend{}