cpython/Include/pycapsule.h
2010-03-25 00:54:54 +00:00

148 lines
4.6 KiB
C

/* Capsule objects let you wrap a C "void *" pointer in a Python
object. They're a way of passing data through the Python interpreter
without creating your own custom type.
Capsules are used for communication between extension modules.
They provide a way for an extension module to export a C interface
to other extension modules, so that extension modules can use the
Python import mechanism to link to one another.
For more information, please see "c-api/capsule.html" in the
documentation.
*/
#ifndef Py_CAPSULE_H
#define Py_CAPSULE_H
#ifdef __cplusplus
extern "C" {
#endif
PyAPI_DATA(PyTypeObject) PyCapsule_Type;
typedef void (*PyCapsule_Destructor)(PyObject *);
#define PyCapsule_CheckExact(op) (Py_TYPE(op) == &PyCapsule_Type)
PyAPI_FUNC(PyObject *) PyCapsule_New(
void *pointer,
const char *name,
PyCapsule_Destructor destructor);
PyAPI_FUNC(void *) PyCapsule_GetPointer(PyObject *capsule, const char *name);
PyAPI_FUNC(PyCapsule_Destructor) PyCapsule_GetDestructor(PyObject *capsule);
PyAPI_FUNC(const char *) PyCapsule_GetName(PyObject *capsule);
PyAPI_FUNC(void *) PyCapsule_GetContext(PyObject *capsule);
PyAPI_FUNC(int) PyCapsule_IsValid(PyObject *capsule, const char *name);
PyAPI_FUNC(int) PyCapsule_SetPointer(PyObject *capsule, void *pointer);
PyAPI_FUNC(int) PyCapsule_SetDestructor(PyObject *capsule, PyCapsule_Destructor destructor);
PyAPI_FUNC(int) PyCapsule_SetName(PyObject *capsule, const char *name);
PyAPI_FUNC(int) PyCapsule_SetContext(PyObject *capsule, void *context);
PyAPI_FUNC(void *) PyCapsule_Import(const char *name, int no_block);
#define PYTHON_USING_CAPSULE
#define PYCAPSULE_INSTANTIATE_DESTRUCTOR(name, destructor) \
static void pycapsule_destructor_ ## name(PyObject *ptr) \
{ \
void *p = PyCapsule_GetPointer(ptr, name); \
if (p) { \
destructor(p); \
} \
} \
#define PYCAPSULE_NEW(pointer, name) \
(PyCapsule_New(pointer, name, capsule_destructor_ ## name))
#define PYCAPSULE_ISVALID(capsule, name) \
(PyCapsule_IsValid(capsule, name))
#define PYCAPSULE_DEREFERENCE(capsule, name) \
(PyCapsule_GetPointer(capsule, name))
#define PYCAPSULE_SET(capsule, name, value) \
(PyCapsule_IsValid(capsule, name) && PyCapsule_SetPointer(capsule, value))
/* module and attribute should be specified as string constants */
#define PYCAPSULE_IMPORT(module, attribute) \
(PyCapsule_Import(module "." attribute, 0))
/* begin public-domain code */
/*
** This code was written by Larry Hastings,
** and is dedicated to the public domain.
** It's designed to make it easy to switch
** from CObject to Capsule objects without losing
** backwards compatibility with prior versions
** of CPython. You're encouraged to copy this code
** (including this documentation) into your
** Python C extension.
**
** To use:
** * #define a name for the pointer you store in
** the CObject. If you make the CObject available
** as part of your module's API, this name should
** be "modulename.attributename", and it should be
** considered part of your API (so put it in your
** header file).
** * Specify a PYCAPSULE_INSTANTIATE_DESTRUCTOR(), in
** every C file that creates these CObjects. This
** is where you specify your object's destructor.
** * Change all calls to CObject_FromVoidPtr()
** and CObject_FromVoidPointerAndDesc() into
** PYCAPSULE_NEW() calls.
** * Change all calls to PyCObject_AsVoidPtr()
** into PYCAPSULE_DEREFERENCE() calls.
** * Change all calls to PyCObject_SetVoidPtr()
** into PYCAPSULE_SET() calls.
** * Change all calls to PyCObject_Import()
** into PYCAPSULE_IMPORT() calls. Note that
** the two arguments to PYCAPSULE_IMPORT()
** should both be string constants; that is,
** you should call
** PYCAPSULE_IMPORT("modulename", "attributename"),
** not PYCAPSULE_IMPORT(charstar1, charstar2).
*/
#ifndef PYTHON_USING_CAPSULE
#define PYCAPSULE_INSTANTIATE_DESTRUCTOR(name, destructor) \
static void pycapsule_destructor_ ## name(void *ptr) \
{ \
destructor(p); \
} \
#define PYCAPSULE_NEW(pointer, name) \
(PyCObject_FromVoidPtr(pointer, pycapsule_destructor_ ## name))
#define PYCAPSULE_ISVALID(capsule, name) \
(PyCObject_Check(capsule))
#define PYCAPSULE_DEREFERENCE(capsule, name) \
(PyCObject_AsVoidPtr(capsule))
#define PYCAPSULE_SET(capsule, name, value) \
(PyCObject_SetVoidPtr(capsule, value))
/* module and attribute should be specified as string constants */
#define PYCAPSULE_IMPORT(module, attribute) \
(PyCObject_Import(module, attribute))
#endif /* PYTHON_USING_CAPSULE */
/* end public-domain code */
#ifdef __cplusplus
}
#endif
#endif /* !Py_CAPSULE_H */