| 754 | |
| 755 | |
| 756 | class _PerMessageDeflateDecompressor(object): |
| 757 | def __init__( |
| 758 | self, |
| 759 | persistent: bool, |
| 760 | max_wbits: Optional[int], |
| 761 | max_message_size: int, |
| 762 | compression_options: Optional[Dict[str, Any]] = None, |
| 763 | ) -> None: |
| 764 | self._max_message_size = max_message_size |
| 765 | if max_wbits is None: |
| 766 | max_wbits = zlib.MAX_WBITS |
| 767 | if not (8 <= max_wbits <= zlib.MAX_WBITS): |
| 768 | raise ValueError( |
| 769 | "Invalid max_wbits value %r; allowed range 8-%d", |
| 770 | max_wbits, |
| 771 | zlib.MAX_WBITS, |
| 772 | ) |
| 773 | self._max_wbits = max_wbits |
| 774 | if persistent: |
| 775 | self._decompressor = ( |
| 776 | self._create_decompressor() |
| 777 | ) # type: Optional[_Decompressor] |
| 778 | else: |
| 779 | self._decompressor = None |
| 780 | |
| 781 | def _create_decompressor(self) -> "_Decompressor": |
| 782 | return zlib.decompressobj(-self._max_wbits) |
| 783 | |
| 784 | def decompress(self, data: bytes) -> bytes: |
| 785 | decompressor = self._decompressor or self._create_decompressor() |
| 786 | result = decompressor.decompress( |
| 787 | data + b"\x00\x00\xff\xff", self._max_message_size |
| 788 | ) |
| 789 | if decompressor.unconsumed_tail: |
| 790 | raise _DecompressTooLargeError() |
| 791 | return result |
| 792 | |
| 793 | |
| 794 | class WebSocketProtocol13(WebSocketProtocol): |