# 旧缓冲协议

This section describes the legacy buffer protocol, which has been introduced in Python 1.6. It is still supported but deprecated in the Python 2.x series. Python 3 introduces a new buffer protocol which fixes weaknesses and shortcomings of the protocol, and has been backported to Python 2.6. See Buffers and Memoryview Objects for more information.

int `PyObject_AsCharBuffer`(PyObject *obj, const char **buffer, Py_ssize_t *buffer_len)

  返回一个可用作基于字符的输入的只读内存地址的指针。 obj 参数必须支持单段字符缓冲接口。 成功时返回 `0`，将 buffer 设为内存地址并将 buffer_len 设为缓冲区长度。 出错时返回 `-1` 并设置一个 `TypeError`。

  1.6 新版功能.

  在 2.5 版更改: This function used an `int *` type for buffer_len. This might require changes in your code for properly supporting 64-bit systems.

int `PyObject_AsReadBuffer`(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len)

  返回一个指向包含任意数据的只读内存地址的指针。 obj 参数必须支持单段可读缓冲接口。 成功时返回 `0`，将 buffer 设为内存地址并将 buffer_len 设为缓冲区长度。 出错时返回 `-1` 并设置一个 `TypeError`。

  1.6 新版功能.

  在 2.5 版更改: This function used an `int *` type for buffer_len. This might require changes in your code for properly supporting 64-bit systems.

int `PyObject_CheckReadBuffer`(PyObject *o)

  Returns `1` if o supports the single-segment readable buffer interface. Otherwise returns `0`.

  2.2 新版功能.

int `PyObject_AsWriteBuffer`(PyObject *obj, void **buffer, Py_ssize_t *buffer_len)

  Returns a pointer to a writeable memory location. The obj argument must support the single-segment, character buffer interface. On success, returns `0`, sets buffer to the memory location and buffer_len to the buffer length. Returns `-1` and sets a `TypeError` on error.

  1.6 新版功能.

  在 2.5 版更改: This function used an `int *` type for buffer_len. This might require changes in your code for properly supporting 64-bit systems.