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)

Return value: New reference.

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)

Return value: New reference.

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)

Return value: New reference.

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)

Return value: New reference.

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。