数据 marshal 操作支持
*********************

这些例程允许 C 代码处理与 "marshal" 模块所用相同数据格式的序列化对象。
其中有些函数可用来将数据写入这种序列化格式，另一些函数则可用来读取并恢
复数据。 用于存储 marshal 数据的文件必须以二进制模式打开。

数字值在存储时会将最低位字节放在开头。

此模块支持两种数据格式版本：第 0 版为历史版本，第 1 版本会在文件和
marshal 反序列化中共享固化的字符串。 第 2 版本会对浮点数使用二进制格式
。 "Py_MARSHAL_VERSION" 指明了当前文件的格式（当前取值为 2）。

void PyMarshal_WriteLongToFile(long value, FILE *file, int version)

   Marshal a long integer, *value*, to *file*.  This will only write
   the least-significant 32 bits of *value*; regardless of the size of
   the native long type.  *version* indicates the file format.

   This function can fail, in which case it sets the error indicator.
   Use "PyErr_Occurred()" to check for that.

void PyMarshal_WriteObjectToFile(PyObject *value, FILE *file, int version)

   将一个 Python 对象 *value* 以 marshal 格式写入 *file*。 *version*
   指明文件格式的版本。

   This function can fail, in which case it sets the error indicator.
   Use "PyErr_Occurred()" to check for that.

PyObject *PyMarshal_WriteObjectToString(PyObject *value, int version)
    *回傳值：新的參照。*

   返回一个包含 *value* 的 marshal 表示形式的字节串对象。 *version* 指
   明文件格式的版本。

以下函数允许读取并恢复存储为 marshal 格式的值。

long PyMarshal_ReadLongFromFile(FILE *file)

   Return a C long from the data stream in a FILE* opened for reading.
   Only a 32-bit value can be read in using this function, regardless
   of the native size of long.

   发生错误时，将设置适当的异常 ("EOFError") 并返回 "-1"。

int PyMarshal_ReadShortFromFile(FILE *file)

   Return a C short from the data stream in a FILE* opened for
   reading.  Only a 16-bit value can be read in using this function,
   regardless of the native size of short.

   发生错误时，将设置适当的异常 ("EOFError") 并返回 "-1"。

PyObject *PyMarshal_ReadObjectFromFile(FILE *file)
    *回傳值：新的參照。*

   Return a Python object from the data stream in a FILE* opened for
   reading.

   发生错误时，将设置适当的异常 ("EOFError", "ValueError" 或
   "TypeError") 并返回 "NULL"。

PyObject *PyMarshal_ReadLastObjectFromFile(FILE *file)
    *回傳值：新的參照。*

   Return a Python object from the data stream in a FILE* opened for
   reading.  Unlike "PyMarshal_ReadObjectFromFile()", this function
   assumes that no further objects will be read from the file,
   allowing it to aggressively load file data into memory so that the
   de-serialization can operate from data in memory rather than
   reading a byte at a time from the file.  Only use these variant if
   you are certain that you won't be reading anything else from the
   file.

   发生错误时，将设置适当的异常 ("EOFError", "ValueError" 或
   "TypeError") 并返回 "NULL"。

PyObject *PyMarshal_ReadObjectFromString(const char *data, Py_ssize_t len)
    *回傳值：新的參照。*

   从包含指向 *data* 的 *len* 个字节的字节缓冲区对应的数据流返回一个
   Python 对象。

   发生错误时，将设置适当的异常 ("EOFError", "ValueError" 或
   "TypeError") 并返回 "NULL"。
