Golang errors.New函數代碼示例

// ParseConfig parses the string s and extracts the s3 config. The two
// supported configuration formats are s3://host/bucketname/prefix and
// s3:host:bucketname/prefix. The host can also be a valid s3 region
// name. If no prefix is given the prefix "restic" will be used.
func ParseConfig(s string) (interface{}, error) {
	switch {
	case strings.HasPrefix(s, "s3:http"):
		// assume that a URL has been specified, parse it and
		// use the host as the endpoint and the path as the
		// bucket name and prefix
		url, err := url.Parse(s[3:])
		if err != nil {
			return nil, errors.Wrap(err, "url.Parse")
		}

		if url.Path == "" {
			return nil, errors.New("s3: bucket name not found")
		}

		path := strings.SplitN(url.Path[1:], "/", 2)
		return createConfig(url.Host, path, url.Scheme == "http")
	case strings.HasPrefix(s, "s3://"):
		s = s[5:]
	case strings.HasPrefix(s, "s3:"):
		s = s[3:]
	default:
		return nil, errors.New("s3: invalid format")
	}
	// use the first entry of the path as the endpoint and the
	// remainder as bucket name and prefix
	path := strings.SplitN(s, "/", 3)
	return createConfig(path[0], path[1:], false)
}

// Valid returns an error if h is not valid.
func (h Handle) Valid() error {
	if h.Type == "" {
		return errors.New("type is empty")
	}

	switch h.Type {
	case DataFile:
	case KeyFile:
	case LockFile:
	case SnapshotFile:
	case IndexFile:
	case ConfigFile:
	default:
		return errors.Errorf("invalid Type %q", h.Type)
	}

	if h.Type == ConfigFile {
		return nil
	}

	if h.Name == "" {
		return errors.New("invalid Name")
	}

	return nil
}

// forgetfulBackend returns a backend that forgets everything.
func forgetfulBackend() restic.Backend {
	be := &mock.Backend{}

	be.TestFn = func(t restic.FileType, name string) (bool, error) {
		return false, nil
	}

	be.LoadFn = func(h restic.Handle, p []byte, off int64) (int, error) {
		return 0, errors.New("not found")
	}

	be.SaveFn = func(h restic.Handle, p []byte) error {
		return nil
	}

	be.StatFn = func(h restic.Handle) (restic.FileInfo, error) {
		return restic.FileInfo{}, errors.New("not found")
	}

	be.RemoveFn = func(t restic.FileType, name string) error {
		return nil
	}

	be.ListFn = func(t restic.FileType, done <-chan struct{}) <-chan string {
		ch := make(chan string)
		close(ch)
		return ch
	}

	be.DeleteFn = func() error {
		return nil
	}

	return be
}

// readHeader reads the header at the end of rd. size is the length of the
// whole data accessible in rd.
func readHeader(rd io.ReaderAt, size int64) ([]byte, error) {
	hl, err := readHeaderLength(rd, size)
	if err != nil {
		return nil, err
	}

	if int64(hl) > size-int64(binary.Size(hl)) {
		return nil, errors.New("header is larger than file")
	}

	if int64(hl) > maxHeaderSize {
		return nil, errors.New("header is larger than maxHeaderSize")
	}

	buf := make([]byte, int(hl))
	n, err := rd.ReadAt(buf, size-int64(hl)-int64(binary.Size(hl)))
	if err != nil {
		return nil, errors.Wrap(err, "ReadAt")
	}

	if n != len(buf) {
		return nil, errors.New("not enough bytes read")
	}

	return buf, nil
}

func (c *Checker) checkTree(id restic.ID, tree *restic.Tree) (errs []error) {
	debug.Log("checking tree %v", id.Str())

	var blobs []restic.ID

	for _, node := range tree.Nodes {
		switch node.Type {
		case "file":
			if node.Content == nil {
				errs = append(errs, Error{TreeID: id, Err: errors.Errorf("file %q has nil blob list", node.Name)})
			}

			for b, blobID := range node.Content {
				if blobID.IsNull() {
					errs = append(errs, Error{TreeID: id, Err: errors.Errorf("file %q blob %d has null ID", node.Name, b)})
					continue
				}
				blobs = append(blobs, blobID)
			}
		case "dir":
			if node.Subtree == nil {
				errs = append(errs, Error{TreeID: id, Err: errors.Errorf("dir node %q has no subtree", node.Name)})
				continue
			}

			if node.Subtree.IsNull() {
				errs = append(errs, Error{TreeID: id, Err: errors.Errorf("dir node %q subtree id is null", node.Name)})
				continue
			}

		case "symlink", "socket", "chardev", "dev", "fifo":
			// nothing to check

		default:
			errs = append(errs, Error{TreeID: id, Err: errors.Errorf("node %q with invalid type %q", node.Name, node.Type)})
		}

		if node.Name == "" {
			errs = append(errs, Error{TreeID: id, Err: errors.New("node with empty name")})
		}
	}

	for _, blobID := range blobs {
		c.blobRefs.Lock()
		c.blobRefs.M[blobID]++
		debug.Log("blob %v refcount %d", blobID.Str(), c.blobRefs.M[blobID])
		c.blobRefs.Unlock()

		if !c.blobs.Has(blobID) {
			debug.Log("tree %v references blob %v which isn't contained in index", id.Str(), blobID.Str())

			errs = append(errs, Error{TreeID: id, BlobID: blobID, Err: errors.New("not found in index")})
		}
	}

	return errs
}

// writeToTempfile saves p into a tempfile in tempdir.
func writeToTempfile(tempdir string, p []byte) (filename string, err error) {
	tmpfile, err := ioutil.TempFile(tempdir, "temp-")
	if err != nil {
		return "", errors.Wrap(err, "TempFile")
	}

	n, err := tmpfile.Write(p)
	if err != nil {
		return "", errors.Wrap(err, "Write")
	}

	if n != len(p) {
		return "", errors.New("not all bytes writen")
	}

	if err = tmpfile.Sync(); err != nil {
		return "", errors.Wrap(err, "Syncn")
	}

	err = tmpfile.Close()
	if err != nil {
		return "", errors.Wrap(err, "Close")
	}

	return tmpfile.Name(), nil
}

func packIDTester(repo restic.Repository, inChan <-chan restic.ID, errChan chan<- error, wg *sync.WaitGroup, done <-chan struct{}) {
	debug.Log("worker start")
	defer debug.Log("worker done")

	defer wg.Done()

	for id := range inChan {
		ok, err := repo.Backend().Test(restic.DataFile, id.String())
		if err != nil {
			err = PackError{ID: id, Err: err}
		} else {
			if !ok {
				err = PackError{ID: id, Err: errors.New("does not exist")}
			}
		}

		if err != nil {
			debug.Log("error checking for pack %s: %v", id.Str(), err)
			select {
			case <-done:
				return
			case errChan <- err:
			}

			continue
		}

		debug.Log("pack %s exists", id.Str())
	}
}

// Delete calls backend.Delete() if implemented, and returns an error
// otherwise.
func (r *Repository) Delete() error {
	if b, ok := r.be.(restic.Deleter); ok {
		return b.Delete()
	}

	return errors.New("Delete() called for backend that does not implement this method")
}

// Encrypt encrypts and authenticates the plaintext and saves the result in
// ciphertext.
func (r *Repository) Encrypt(ciphertext, plaintext []byte) ([]byte, error) {
	if r.key == nil {
		return nil, errors.New("key for repository not set")
	}

	return crypto.Encrypt(r.key, ciphertext, plaintext)
}

// decrypt authenticates and decrypts ciphertext and stores the result in
// plaintext.
func (r *Repository) decryptTo(plaintext, ciphertext []byte) (int, error) {
	if r.key == nil {
		return 0, errors.New("key for repository not set")
	}

	return crypto.Decrypt(r.key, plaintext, ciphertext)
}

// Delete all data.
func (m *Backend) Delete() error {
	if m.DeleteFn == nil {
		return errors.New("not implemented")
	}

	return m.DeleteFn()
}

// Test for the existence of a specific item.
func (m *Backend) Test(t restic.FileType, name string) (bool, error) {
	if m.TestFn == nil {
		return false, errors.New("not implemented")
	}

	return m.TestFn(t, name)
}

// Remove data from the backend.
func (m *Backend) Remove(t restic.FileType, name string) error {
	if m.RemoveFn == nil {
		return errors.New("not implemented")
	}

	return m.RemoveFn(t, name)
}

// Stat an object in the backend.
func (m *Backend) Stat(h restic.Handle) (restic.FileInfo, error) {
	if m.StatFn == nil {
		return restic.FileInfo{}, errors.New("not implemented")
	}

	return m.StatFn(h)
}

// Save data in the backend.
func (m *Backend) Save(h restic.Handle, p []byte) error {
	if m.SaveFn == nil {
		return errors.New("not implemented")
	}

	return m.SaveFn(h, p)
}