5.4 Data marshalling support
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.
-
| void PyMarshal_WriteLongToFile( |
long value, FILE *file) |
- 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.
-
| void PyMarshal_WriteObjectToFile( |
PyObject *value, FILE *file) |
- Marshal a Python object, value, to file.
-
| PyObject* PyMarshal_WriteObjectToString( |
PyObject *value) |
-
Return value: New reference.
Return a string object containing the marshalled representation of value.
The following functions allow marshalled values to be read back in.
XXX What about error detection? It appears that reading past the end of the file will
always result in a negative numeric value (where that's relevant), but it's not clear that
negative values won't be handled properly when there's no error. What's the right way to tell?
Should only non-negative values be written using these routines?
-
| 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.
-
| 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.
-
| PyObject* 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 or TypeError) and returns 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. On error, sets the
appropriate exception (EOFError or TypeError)
and returns NULL.
-
| PyObject* PyMarshal_ReadObjectFromString( |
char *string, int len) |
-
Return value: New reference.
Return a Python object from the data stream in a character buffer containing len
bytes pointed to by string. On error, sets the appropriate exception (EOFError or TypeError) and returns NULL.
|
