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Diffstat (limited to 'Doc/c-api/capsule.rst')
| -rw-r--r-- | Doc/c-api/capsule.rst | 132 |
1 files changed, 58 insertions, 74 deletions
diff --git a/Doc/c-api/capsule.rst b/Doc/c-api/capsule.rst index 163ad60..05a453c 100644 --- a/Doc/c-api/capsule.rst +++ b/Doc/c-api/capsule.rst @@ -33,107 +33,94 @@ Refer to :ref:`using-capsules` for more information on using these objects. Return true if its argument is a :ctype:`PyCapsule`. + .. cfunction:: PyObject* PyCapsule_New(void* pointer, const char* name, PyCapsule_Destructor destructor) Create a :ctype:`PyCapsule` encapsulating the *pointer*. The *pointer* argument may not be *NULL*. - The *name* string may either be *NULL* or a pointer to a valid - C string. If non-*NULL*, this string must outlive the capsule. - (Though it is permitted to free it inside the *destructor*.) - - If the *destructor* argument is not *NULL*, - it will be called with the capsule ``PyObject *`` when it is destroyed. - - If this capsule will be stored as an attribute of a module, it - is strongly suggested that the *name* string be specified as:: + On failure, set an exception and return *NULL*. - modulename.attributename + The *name* string may either be *NULL* or a pointer to a valid C string. If + non-*NULL*, this string must outlive the capsule. (Though it is permitted to + free it inside the *destructor*.) - This will enable other modules to import the capsule - using :cfunc:`PyCapsule_Import`. + If the *destructor* argument is not *NULL*, it will be called with the + capsule when it is destroyed. - Return a valid capsule on success. - On failure, set an exception and return *NULL*. + If this capsule will be stored as an attribute of a module, the *name* should + be specified as ``modulename.attributename``. This will enable other modules + to import the capsule using :cfunc:`PyCapsule_Import`. .. cfunction:: void* PyCapsule_GetPointer(PyObject* capsule, const char* name) - Retrieve the *pointer* stored in the capsule. + Retrieve the *pointer* stored in the capsule. On failure, set an exception + and return *NULL*. The *name* parameter must compare exactly to the name stored in the capsule. - If the name stored in the capsule is *NULL*, the *name* passed in must - also be *NULL*. If the name stored in the capsule is non-*NULL*, - the *name* passed in must also be non-*NULL*, and must match the name - stored in the capsule. Python uses the C function *strcmp* to compare - capsule names. - - Return the internal *pointer* on success. - On failure, set an exception and return *NULL*. + If the name stored in the capsule is *NULL*, the *name* passed in must also + be *NULL*. Python uses the C function :cfunc:`strcmp` to compare capsule + names. .. cfunction:: PyCapsule_Destructor PyCapsule_GetDestructor(PyObject* capsule) - Return the current *destructor* stored in the capsule. - On failure, set an exception and return *NULL*. + Return the current destructor stored in the capsule. On failure, set an + exception and return *NULL*. - It is legal for a capsule to have a *NULL* destructor. - This makes a *NULL* return code somewhat ambiguous; - use :cfunc:`PyCapsule_IsValid` or :cfunc:`PyErr_Occurred` to disambugate. + It is legal for a capsule to have a *NULL* destructor. This makes a *NULL* + return code somewhat ambiguous; use :cfunc:`PyCapsule_IsValid` or + :cfunc:`PyErr_Occurred` to disambugate. .. cfunction:: void* PyCapsule_GetContext(PyObject* capsule) - Return the current *context* stored in the capsule. - On failure, set an exception and return *NULL*. + Return the current context stored in the capsule. On failure, set an + exception and return *NULL*. - It is legal for a capsule to have a *NULL* context. - This makes a *NULL* return code somewhat ambiguous; - use :cfunc:`PyCapsule_IsValid` or :cfunc:`PyErr_Occurred` to disambugate. + It is legal for a capsule to have a *NULL* context. This makes a *NULL* + return code somewhat ambiguous; use :cfunc:`PyCapsule_IsValid` or + :cfunc:`PyErr_Occurred` to disambugate. .. cfunction:: const char* PyCapsule_GetName(PyObject* capsule) - Return the current *name* stored in the capsule. - On failure, set an exception and return *NULL*. + Return the current name stored in the capsule. On failure, set an exception + and return *NULL*. - It is legal for a capsule to have a *NULL* name. - This makes a *NULL* return code somewhat ambiguous; - use :cfunc:`PyCapsule_IsValid` or :cfunc:`PyErr_Occurred` to disambugate. + It is legal for a capsule to have a *NULL* name. This makes a *NULL* return + code somewhat ambiguous; use :cfunc:`PyCapsule_IsValid` or + :cfunc:`PyErr_Occurred` to disambugate. .. cfunction:: void* PyCapsule_Import(const char* name, int no_block) - Import a pointer to a C object from a ``capsule`` attribute in a module. - The *name* parameter should specify the full name to the attribute, as - in *"module.attribute"*. - The *name* stored in the capsule must match this string exactly. - If *no_block* is true, import the module without blocking - (using :cfunc:`PyImport_ImportModuleNoBlock`). - If *no_block* is false, import the module conventionally - (using :cfunc:`PyImport_ImportModule`). + Import a pointer to a C object from a ``capsule`` attribute in a module. The + *name* parameter should specify the full name to the attribute, as in + ``module.attribute``. The *name* stored in the capsule must match this + string exactly. If *no_block* is true, import the module without blocking + (using :cfunc:`PyImport_ImportModuleNoBlock`). If *no_block* is false, + import the module conventionally (using :cfunc:`PyImport_ImportModule`). - Return the capsule's internal *pointer* on success. - On failure, set an exception and return *NULL*. - Exception: if *PyCapsule_Import* failed to import the module, - and *no_block* was true, no exception is set. + Return the capsule's internal *pointer* on success. On failure, set an + exception and return *NULL*. However, if :cfunc:`PyCapsule_Import` failed to + import the module, and *no_block* was true, no exception is set. .. cfunction:: int PyCapsule_IsValid(PyObject* capsule, const char* name) - Determines whether or not a :ctype:`PyObject \*` is a valid capsule. - A valid capsule is non-*NULL*, passes :cfunc:`PyCapsule_CheckExact`, - has a non-NULL *pointer*, and its internal name matches the - *name* parameter. (See :cfunc:`PyCapsule_GetPointer` for - information on how capsule names are compared.) + Determines whether or not *capsule* is a valid capsule. A valid capsule is + non-*NULL*, passes :cfunc:`PyCapsule_CheckExact`, has a non-NULL pointer + stored in it, and its internal name matches the *name* parameter. (See + :cfunc:`PyCapsule_GetPointer` for information on how capsule names are + compared.) - In other words, if :cfunc:`PyCapsule_IsValid` returns a true value, - calls to any of the accessors (any function starting - with :cfunc:`PyCapsule_Get`) are guaranteed to succeed. + In other words, if :cfunc:`PyCapsule_IsValid` returns a true value, calls to + any of the accessors (any function starting with :cfunc:`PyCapsule_Get`) are + guaranteed to succeed. - Return a nonzero value if the object is valid and matches the name - passed in. - Return 0 otherwise. - This function will not fail. + Return a nonzero value if the object is valid and matches the name passed in. + Return 0 otherwise. This function will not fail. .. cfunction:: int PyCapsule_SetContext(PyObject* capsule, void* context) @@ -142,27 +129,24 @@ Refer to :ref:`using-capsules` for more information on using these objects. Return 0 on success. Return nonzero and set an exception on failure. -.. cfunction:: int PyCapsule_SetDestructor(PyObject* capsule, void (*)(PyObject *) destructor) +.. cfunction:: int PyCapsule_SetDestructor(PyObject* capsule, PyCapsule_Destructor destructor) Set the destructor inside *capsule* to *destructor*. - Return 0 on success. - Return nonzero and set an exception on failure. + Return 0 on success. Return nonzero and set an exception on failure. .. cfunction:: int PyCapsule_SetName(PyObject* capsule, const char* name) - Set the name inside *capsule* to *name*. If non-*NULL*, the name - must outlive the capsule. If the previous *name* stored in the - capsule was not *NULL*, no attempt is made to free it. + Set the name inside *capsule* to *name*. If non-*NULL*, the name must + outlive the capsule. If the previous *name* stored in the capsule was not + *NULL*, no attempt is made to free it. - Return 0 on success. - Return nonzero and set an exception on failure. + Return 0 on success. Return nonzero and set an exception on failure. .. cfunction:: int PyCapsule_SetPointer(PyObject* capsule, void* pointer) - Set the void pointer inside *capsule* to *pointer*. The pointer - may not be *NULL*. + Set the void pointer inside *capsule* to *pointer*. The pointer may not be + *NULL*. - Return 0 on success. - Return nonzero and set an exception on failure. + Return 0 on success. Return nonzero and set an exception on failure. |