Method Open

backend/crypt/crypt.go:1050–1088

Open opens the file for read. Call Close() on the returned io.ReadCloser

(ctx context.Context, options ...fs.OpenOption)

// Open opens the file for read.  Call Close() on the returned io.ReadCloser
func (o *Object) Open(ctx context.Context, options ...fs.OpenOption) (rc io.ReadCloser, err error) {
	if o.f.opt.NoDataEncryption {
		return o.Object.Open(ctx, options...)
	}

	var openOptions []fs.OpenOption
	var offset, limit int64 = 0, -1
	for _, option := range options {
		switch x := option.(type) {
		case *fs.SeekOption:
			offset = x.Offset
		case *fs.RangeOption:
			offset, limit = x.Decode(o.Size())
		default:
			// pass on Options to underlying open if appropriate
			openOptions = append(openOptions, option)
		}
	}
	rc, err = o.f.cipher.DecryptDataSeek(ctx, func(ctx context.Context, underlyingOffset, underlyingLimit int64) (io.ReadCloser, error) {
		if underlyingOffset == 0 && underlyingLimit < 0 {
			// Open with no seek
			return o.Object.Open(ctx, openOptions...)
		}
		// Open stream with a range of underlyingOffset, underlyingLimit
		end := int64(-1)
		if underlyingLimit >= 0 {
			end = underlyingOffset + underlyingLimit - 1
			if end >= o.Object.Size() {
				end = -1
			}
		}
		newOpenOptions := append(openOptions, &fs.RangeOption{Start: underlyingOffset, End: end})
		return o.Object.Open(ctx, newOpenOptions...)
	}, offset, limit)
	if err != nil {
		return nil, err
	}
	return rc, nil
}

// Update in to the object with the modTime given of the given size
func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) error {