Antoine Pitrou | 789be0c | 2009-04-02 21:18:34 +0000 | [diff] [blame] | 1 | /* Memory view object. In Python this is available as "memoryview". */ |
| 2 | |
| 3 | #ifndef Py_MEMORYOBJECT_H |
| 4 | #define Py_MEMORYOBJECT_H |
| 5 | #ifdef __cplusplus |
| 6 | extern "C" { |
| 7 | #endif |
| 8 | |
| 9 | PyAPI_DATA(PyTypeObject) PyMemoryView_Type; |
| 10 | |
| 11 | #define PyMemoryView_Check(op) (Py_TYPE(op) == &PyMemoryView_Type) |
| 12 | |
| 13 | /* Get a pointer to the underlying Py_buffer of a memoryview object. */ |
| 14 | #define PyMemoryView_GET_BUFFER(op) (&((PyMemoryViewObject *)(op))->view) |
| 15 | /* Get a pointer to the PyObject from which originates a memoryview object. */ |
| 16 | #define PyMemoryView_GET_BASE(op) (((PyMemoryViewObject *)(op))->view.obj) |
| 17 | |
| 18 | |
| 19 | PyAPI_FUNC(PyObject *) PyMemoryView_GetContiguous(PyObject *base, |
| 20 | int buffertype, |
| 21 | char fort); |
| 22 | |
| 23 | /* Return a contiguous chunk of memory representing the buffer |
| 24 | from an object in a memory view object. If a copy is made then the |
| 25 | base object for the memory view will be a *new* bytes object. |
| 26 | |
| 27 | Otherwise, the base-object will be the object itself and no |
| 28 | data-copying will be done. |
| 29 | |
| 30 | The buffertype argument can be PyBUF_READ, PyBUF_WRITE, |
| 31 | PyBUF_SHADOW to determine whether the returned buffer |
| 32 | should be READONLY, WRITABLE, or set to update the |
| 33 | original buffer if a copy must be made. If buffertype is |
| 34 | PyBUF_WRITE and the buffer is not contiguous an error will |
| 35 | be raised. In this circumstance, the user can use |
| 36 | PyBUF_SHADOW to ensure that a a writable temporary |
| 37 | contiguous buffer is returned. The contents of this |
| 38 | contiguous buffer will be copied back into the original |
| 39 | object after the memoryview object is deleted as long as |
| 40 | the original object is writable and allows setting an |
| 41 | exclusive write lock. If this is not allowed by the |
| 42 | original object, then a BufferError is raised. |
| 43 | |
| 44 | If the object is multi-dimensional and if fortran is 'F', |
| 45 | the first dimension of the underlying array will vary the |
| 46 | fastest in the buffer. If fortran is 'C', then the last |
| 47 | dimension will vary the fastest (C-style contiguous). If |
| 48 | fortran is 'A', then it does not matter and you will get |
| 49 | whatever the object decides is more efficient. |
| 50 | |
| 51 | A new reference is returned that must be DECREF'd when finished. |
| 52 | */ |
| 53 | |
| 54 | PyAPI_FUNC(PyObject *) PyMemoryView_FromObject(PyObject *base); |
| 55 | |
| 56 | PyAPI_FUNC(PyObject *) PyMemoryView_FromBuffer(Py_buffer *info); |
| 57 | /* create new if bufptr is NULL |
| 58 | will be a new bytesobject in base */ |
| 59 | |
| 60 | |
| 61 | /* The struct is declared here so that macros can work, but it shouldn't |
| 62 | be considered public. Don't access those fields directly, use the macros |
| 63 | and functions instead! */ |
| 64 | typedef struct { |
| 65 | PyObject_HEAD |
| 66 | PyObject *base; |
| 67 | Py_buffer view; |
| 68 | } PyMemoryViewObject; |
| 69 | |
| 70 | |
| 71 | #ifdef __cplusplus |
| 72 | } |
| 73 | #endif |
| 74 | #endif /* !Py_MEMORYOBJECT_H */ |