backend: pcloud: Implement OpenWriterAt feature

backend/pcloud/api/types.go

@@ -109,6 +109,37 @@ type Hashes struct {
 	SHA256 string `json:"sha256"`
 }
 
+// FileTruncateResponse is the response from /file_truncate
+type FileTruncateResponse struct {
+	Error
+}
+
+// FileCloseResponse is the response from /file_close
+type FileCloseResponse struct {
+	Error
+}
+
+// FileOpenResponse is the response from /file_open
+type FileOpenResponse struct {
+	Error
+	Fileid         int64 `json:"fileid"`
+	FileDescriptor int64 `json:"fd"`
+}
+
+// FileChecksumResponse is the response from /file_checksum
+type FileChecksumResponse struct {
+	Error
+	MD5    string `json:"md5"`
+	SHA1   string `json:"sha1"`
+	SHA256 string `json:"sha256"`
+}
+
+// FilePWriteResponse is the response from /file_pwrite
+type FilePWriteResponse struct {
+	Error
+	Bytes int64 `json:"bytes"`
+}
+
 // UploadFileResponse is the response from /uploadfile
 type UploadFileResponse struct {
 	Error