| 261 | |
| 262 | |
| 263 | class _Unframer: |
| 264 | |
| 265 | def __init__(self, file_read, file_readline, file_tell=None): |
| 266 | self.file_read = file_read |
| 267 | self.file_readline = file_readline |
| 268 | self.current_frame = None |
| 269 | |
| 270 | def readinto(self, buf): |
| 271 | if self.current_frame: |
| 272 | n = self.current_frame.readinto(buf) |
| 273 | if n == 0 and len(buf) != 0: |
| 274 | self.current_frame = None |
| 275 | n = len(buf) |
| 276 | buf[:] = self.file_read(n) |
| 277 | return n |
| 278 | if n < len(buf): |
| 279 | raise UnpicklingError( |
| 280 | "pickle exhausted before end of frame") |
| 281 | return n |
| 282 | else: |
| 283 | n = len(buf) |
| 284 | buf[:] = self.file_read(n) |
| 285 | return n |
| 286 | |
| 287 | def read(self, n): |
| 288 | if self.current_frame: |
| 289 | data = self.current_frame.read(n) |
| 290 | if not data and n != 0: |
| 291 | self.current_frame = None |
| 292 | return self.file_read(n) |
| 293 | if len(data) < n: |
| 294 | raise UnpicklingError( |
| 295 | "pickle exhausted before end of frame") |
| 296 | return data |
| 297 | else: |
| 298 | return self.file_read(n) |
| 299 | |
| 300 | def readline(self): |
| 301 | if self.current_frame: |
| 302 | data = self.current_frame.readline() |
| 303 | if not data: |
| 304 | self.current_frame = None |
| 305 | return self.file_readline() |
| 306 | if data[-1] != b'\n'[0]: |
| 307 | raise UnpicklingError( |
| 308 | "pickle exhausted before end of frame") |
| 309 | return data |
| 310 | else: |
| 311 | return self.file_readline() |
| 312 | |
| 313 | def load_frame(self, frame_size): |
| 314 | if self.current_frame and self.current_frame.read() != b'': |
| 315 | raise UnpicklingError( |
| 316 | "beginning of a new frame before end of current frame") |
| 317 | self.current_frame = io.BytesIO(self.file_read(frame_size)) |
| 318 | |
| 319 | |
| 320 | # Tools used for pickling. |