These routines allow C code to work with serialized objects using the same
data format as the marshal module. There are functions to write data
into the serialization format, and additional functions that can be used to
read the data back. Files used to store marshalled data must be opened in
binary mode.
Numeric values are stored with the least significant byte first.
The module supports two versions of the data format: version 0 is the
historical version, version 1 shares interned strings in the file, and upon
unmarshalling. Version 2 uses a binary format for floating point numbers.
Py_MARSHAL_VERSION indicates the current file format (currently 2).
PyMarshal_WriteLongToFile(long value, FILE *file, int version)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.PyMarshal_WriteObjectToFile(PyObject *value, FILE *file, int version)PyMarshal_WriteObjectToString(PyObject *value, int version)Return value: New reference.
Return a bytes object containing the marshalled representation of value. version indicates the file format.
The following functions allow marshalled values to be read back in.
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.
On error, sets the appropriate exception (EOFError) and returns
-1.
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.
On error, sets the appropriate exception (EOFError) and returns
-1.
PyMarshal_ReadObjectFromFile(FILE *file)Return value: New reference.
Return a Python object from the data stream in a FILE* opened for
reading.
On error, sets the appropriate exception (EOFError, ValueError
or TypeError) and returns NULL.
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.
On error, sets the appropriate exception (EOFError, ValueError
or TypeError) and returns NULL.
PyMarshal_ReadObjectFromString(const char *data, Py_ssize_t len)Return value: New reference.
Return a Python object from the data stream in a byte buffer containing len bytes pointed to by data.
On error, sets the appropriate exception (EOFError, ValueError
or TypeError) and returns NULL.