| 50 | |
| 51 | # Fast Binary Encoding write buffer based on the dynamic byte array |
| 52 | class WriteBuffer(object): |
| 53 | __slots__ = "_buffer", "_offset", "_size", |
| 54 | |
| 55 | def __init__(self, capacity=0): |
| 56 | self._buffer = bytearray(capacity) |
| 57 | self._size = 0 |
| 58 | self._offset = 0 |
| 59 | |
| 60 | def __bool__(self): |
| 61 | return not self.empty |
| 62 | |
| 63 | @property |
| 64 | def empty(self): |
| 65 | return (self._buffer is None) or (self._size <= 0) |
| 66 | |
| 67 | @property |
| 68 | def buffer(self): |
| 69 | return self._buffer |
| 70 | |
| 71 | @property |
| 72 | def capacity(self): |
| 73 | return len(self._buffer) |
| 74 | |
| 75 | @property |
| 76 | def size(self): |
| 77 | return self._size |
| 78 | |
| 79 | def __len__(self): |
| 80 | return self._size |
| 81 | |
| 82 | @property |
| 83 | def offset(self): |
| 84 | return self._offset |
| 85 | |
| 86 | # Attach an empty memory buffer |
| 87 | def attach_new(self): |
| 88 | self._buffer = bytearray() |
| 89 | self._size = 0 |
| 90 | self._offset = 0 |
| 91 | |
| 92 | # Attach an empty memory buffer with a given capacity |
| 93 | def attach_capacity(self, capacity): |
| 94 | self._buffer = bytearray(capacity) |
| 95 | self._size = 0 |
| 96 | self._offset = 0 |
| 97 | |
| 98 | # Attach a given memory buffer |
| 99 | def attach_buffer(self, buffer, offset=0, size=None): |
| 100 | assert (buffer is not None), "Invalid buffer!" |
| 101 | if buffer is None: |
| 102 | raise ValueError("Invalid buffer!") |
| 103 | |
| 104 | if size is None: |
| 105 | size = len(buffer) |
| 106 | |
| 107 | assert (size > 0), "Invalid size!" |
| 108 | if size <= 0: |
| 109 | raise ValueError("Invalid size!") |