Buffered I/O implementation using an in-memory bytes buffer.
| 900 | |
| 901 | |
| 902 | class BytesIO(BufferedIOBase): |
| 903 | |
| 904 | """Buffered I/O implementation using an in-memory bytes buffer.""" |
| 905 | |
| 906 | # Initialize _buffer as soon as possible since it's used by __del__() |
| 907 | # which calls close() |
| 908 | _buffer = None |
| 909 | |
| 910 | def __init__(self, initial_bytes=None): |
| 911 | buf = bytearray() |
| 912 | if initial_bytes is not None: |
| 913 | buf += initial_bytes |
| 914 | self._buffer = buf |
| 915 | self._pos = 0 |
| 916 | |
| 917 | def __getstate__(self): |
| 918 | if self.closed: |
| 919 | raise ValueError("__getstate__ on closed file") |
| 920 | return self.__dict__.copy() |
| 921 | |
| 922 | def getvalue(self): |
| 923 | """Return the bytes value (contents) of the buffer |
| 924 | """ |
| 925 | if self.closed: |
| 926 | raise ValueError("getvalue on closed file") |
| 927 | return bytes(self._buffer) |
| 928 | |
| 929 | def getbuffer(self): |
| 930 | """Return a readable and writable view of the buffer. |
| 931 | """ |
| 932 | if self.closed: |
| 933 | raise ValueError("getbuffer on closed file") |
| 934 | return memoryview(self._buffer) |
| 935 | |
| 936 | def close(self): |
| 937 | if self._buffer is not None: |
| 938 | self._buffer.clear() |
| 939 | super().close() |
| 940 | |
| 941 | def read(self, size=-1): |
| 942 | if self.closed: |
| 943 | raise ValueError("read from closed file") |
| 944 | if size is None: |
| 945 | size = -1 |
| 946 | else: |
| 947 | try: |
| 948 | size_index = size.__index__ |
| 949 | except AttributeError: |
| 950 | raise TypeError(f"{size!r} is not an integer") |
| 951 | else: |
| 952 | size = size_index() |
| 953 | if size < 0: |
| 954 | size = len(self._buffer) |
| 955 | if len(self._buffer) <= self._pos: |
| 956 | return b"" |
| 957 | newpos = min(len(self._buffer), self._pos + size) |
| 958 | b = self._buffer[self._pos : newpos] |
| 959 | self._pos = newpos |
no outgoing calls