backend: remove unused ErrorBackend

internal/backend/backend_error.go

@@ -1,84 +0,0 @@
-package backend
-
-import (
-	"context"
-	"io"
-	"io/ioutil"
-	"math/rand"
-	"sync"
-
-	"github.com/restic/restic/internal/errors"
-	"github.com/restic/restic/internal/restic"
-)
-
-// ErrorBackend is used to induce errors into various function calls and test
-// the retry functions.
-type ErrorBackend struct {
-	FailSave     float32
-	FailSaveRead float32
-	FailLoad     float32
-	FailStat     float32
-	restic.Backend
-
-	r *rand.Rand
-	m sync.Mutex
-}
-
-// statically ensure that ErrorBackend implements restic.Backend.
-var _ restic.Backend = &ErrorBackend{}
-
-// NewErrorBackend wraps be with a backend that returns errors according to
-// given probabilities.
-func NewErrorBackend(be restic.Backend, seed int64) *ErrorBackend {
-	return &ErrorBackend{
-		Backend: be,
-		r:       rand.New(rand.NewSource(seed)),
-	}
-}
-
-func (be *ErrorBackend) fail(p float32) bool {
-	be.m.Lock()
-	v := be.r.Float32()
-	be.m.Unlock()
-
-	return v < p
-}
-
-// Save stores the data in the backend under the given handle.
-func (be *ErrorBackend) Save(ctx context.Context, h restic.Handle, rd restic.RewindReader) error {
-	if be.fail(be.FailSave) {
-		return errors.Errorf("Save(%v) random error induced", h)
-	}
-
-	if be.fail(be.FailSaveRead) {
-		_, err := io.CopyN(ioutil.Discard, rd, be.r.Int63n(1000))
-		if err != nil {
-			return err
-		}
-
-		return errors.Errorf("Save(%v) random error with partial read induced", h)
-	}
-
-	return be.Backend.Save(ctx, h, rd)
-}
-
-// Load returns a reader that yields the contents of the file at h at the
-// given offset. If length is larger than zero, only a portion of the file
-// is returned. rd must be closed after use. If an error is returned, the
-// ReadCloser must be nil.
-func (be *ErrorBackend) Load(ctx context.Context, h restic.Handle, length int, offset int64, consumer func(rd io.Reader) error) error {
-	if be.fail(be.FailLoad) {
-		return errors.Errorf("Load(%v, %v, %v) random error induced", h, length, offset)
-	}
-
-	return be.Backend.Load(ctx, h, length, offset, consumer)
-}
-
-// Stat returns information about the File identified by h.
-func (be *ErrorBackend) Stat(ctx context.Context, h restic.Handle) (restic.FileInfo, error) {
-	if be.fail(be.FailLoad) {
-		return restic.FileInfo{}, errors.Errorf("Stat(%v) random error induced", h)
-	}
-
-	return be.Stat(ctx, h)
-}