diff options
Diffstat (limited to 'Objects/typeobject.c')
| -rw-r--r-- | Objects/typeobject.c | 197 |
1 files changed, 195 insertions, 2 deletions
diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 171c76a..456b10e 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -6,6 +6,7 @@ #include "pycore_symtable.h" // _Py_Mangle() #include "pycore_dict.h" // _PyDict_KeysSize() #include "pycore_initconfig.h" // _PyStatus_OK() +#include "pycore_memoryobject.h" // PyMemoryView_FromObjectAndFlags() #include "pycore_moduleobject.h" // _PyModule_GetDef() #include "pycore_object.h" // _PyType_HasFeature() #include "pycore_long.h" // _PyLong_IsNegative() @@ -8060,6 +8061,58 @@ wrap_descr_delete(PyObject *self, PyObject *args, void *wrapped) } static PyObject * +wrap_buffer(PyObject *self, PyObject *args, void *wrapped) +{ + PyObject *arg = NULL; + + if (!PyArg_UnpackTuple(args, "", 1, 1, &arg)) { + return NULL; + } + Py_ssize_t flags = PyNumber_AsSsize_t(arg, PyExc_OverflowError); + if (flags == -1 && PyErr_Occurred()) { + return NULL; + } + if (flags > INT_MAX) { + PyErr_SetString(PyExc_OverflowError, + "buffer flags too large"); + return NULL; + } + + return PyMemoryView_FromObjectAndFlags(self, Py_SAFE_DOWNCAST(flags, Py_ssize_t, int)); +} + +static PyObject * +wrap_releasebuffer(PyObject *self, PyObject *args, void *wrapped) +{ + PyObject *arg = NULL; + if (!PyArg_UnpackTuple(args, "", 1, 1, &arg)) { + return NULL; + } + if (!PyMemoryView_Check(arg)) { + PyErr_SetString(PyExc_TypeError, + "expected a memoryview object"); + return NULL; + } + PyMemoryViewObject *mview = (PyMemoryViewObject *)arg; + if (mview->view.obj != self) { + PyErr_SetString(PyExc_ValueError, + "memoryview's buffer is not this object"); + return NULL; + } + if (mview->flags & _Py_MEMORYVIEW_RELEASED) { + PyErr_SetString(PyExc_ValueError, + "memoryview's buffer has already been released"); + return NULL; + } + PyObject *res = PyObject_CallMethodNoArgs((PyObject *)mview, &_Py_ID(release)); + if (res == NULL) { + return NULL; + } + Py_DECREF(res); + Py_RETURN_NONE; +} + +static PyObject * wrap_init(PyObject *self, PyObject *args, void *wrapped, PyObject *kwds) { initproc func = (initproc)wrapped; @@ -8895,6 +8948,132 @@ slot_tp_finalize(PyObject *self) PyErr_SetRaisedException(exc); } +typedef struct _PyBufferWrapper { + PyObject_HEAD + PyObject *mv; + PyObject *obj; +} PyBufferWrapper; + +static int +bufferwrapper_traverse(PyBufferWrapper *self, visitproc visit, void *arg) +{ + Py_VISIT(self->mv); + Py_VISIT(self->obj); + return 0; +} + +static void +bufferwrapper_dealloc(PyObject *self) +{ + PyBufferWrapper *bw = (PyBufferWrapper *)self; + + _PyObject_GC_UNTRACK(self); + Py_XDECREF(bw->mv); + Py_XDECREF(bw->obj); + Py_TYPE(self)->tp_free(self); +} + +static void +bufferwrapper_releasebuf(PyObject *self, Py_buffer *view) +{ + PyBufferWrapper *bw = (PyBufferWrapper *)self; + + assert(PyMemoryView_Check(bw->mv)); + Py_TYPE(bw->mv)->tp_as_buffer->bf_releasebuffer(bw->mv, view); + if (Py_TYPE(bw->obj)->tp_as_buffer != NULL + && Py_TYPE(bw->obj)->tp_as_buffer->bf_releasebuffer != NULL) { + Py_TYPE(bw->obj)->tp_as_buffer->bf_releasebuffer(bw->obj, view); + } +} + +static PyBufferProcs bufferwrapper_as_buffer = { + .bf_releasebuffer = bufferwrapper_releasebuf, +}; + + +PyTypeObject _PyBufferWrapper_Type = { + PyVarObject_HEAD_INIT(&PyType_Type, 0) + .tp_name = "_buffer_wrapper", + .tp_basicsize = sizeof(PyBufferWrapper), + .tp_alloc = PyType_GenericAlloc, + .tp_free = PyObject_GC_Del, + .tp_traverse = (traverseproc)bufferwrapper_traverse, + .tp_dealloc = bufferwrapper_dealloc, + .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, + .tp_as_buffer = &bufferwrapper_as_buffer, +}; + +static int +slot_bf_getbuffer(PyObject *self, Py_buffer *buffer, int flags) +{ + PyObject *flags_obj = PyLong_FromLong(flags); + if (flags_obj == NULL) { + return -1; + } + PyBufferWrapper *wrapper = NULL; + PyObject *stack[2] = {self, flags_obj}; + PyObject *ret = vectorcall_method(&_Py_ID(__buffer__), stack, 2); + if (ret == NULL) { + goto fail; + } + if (!PyMemoryView_Check(ret)) { + PyErr_Format(PyExc_TypeError, + "__buffer__ returned non-memoryview object"); + goto fail; + } + + if (PyObject_GetBuffer(ret, buffer, flags) < 0) { + goto fail; + } + assert(buffer->obj == ret); + + wrapper = PyObject_GC_New(PyBufferWrapper, &_PyBufferWrapper_Type); + if (wrapper == NULL) { + goto fail; + } + wrapper->mv = ret; + wrapper->obj = Py_NewRef(self); + _PyObject_GC_TRACK(wrapper); + + buffer->obj = (PyObject *)wrapper; + Py_DECREF(ret); + Py_DECREF(flags_obj); + return 0; + +fail: + Py_XDECREF(wrapper); + Py_XDECREF(ret); + Py_DECREF(flags_obj); + return -1; +} + +static void +slot_bf_releasebuffer(PyObject *self, Py_buffer *buffer) +{ + PyObject *mv; + if (Py_TYPE(buffer->obj) == &_PyBufferWrapper_Type) { + // Make sure we pass the same memoryview to + // __release_buffer__() that __buffer__() returned. + mv = Py_NewRef(((PyBufferWrapper *)buffer->obj)->mv); + } + else { + mv = PyMemoryView_FromBuffer(buffer); + if (mv == NULL) { + PyErr_WriteUnraisable(self); + return; + } + } + PyObject *stack[2] = {self, mv}; + PyObject *ret = vectorcall_method(&_Py_ID(__release_buffer__), stack, 2); + Py_DECREF(mv); + if (ret == NULL) { + PyErr_WriteUnraisable(self); + } + else { + Py_DECREF(ret); + } +} + static PyObject * slot_am_await(PyObject *self) { @@ -8962,6 +9141,7 @@ an all-zero entry. #undef TPSLOT #undef FLSLOT +#undef BUFSLOT #undef AMSLOT #undef ETSLOT #undef SQSLOT @@ -8981,6 +9161,8 @@ an all-zero entry. #define ETSLOT(NAME, SLOT, FUNCTION, WRAPPER, DOC) \ {#NAME, offsetof(PyHeapTypeObject, SLOT), (void *)(FUNCTION), WRAPPER, \ PyDoc_STR(DOC), .name_strobj = &_Py_ID(NAME) } +#define BUFSLOT(NAME, SLOT, FUNCTION, WRAPPER, DOC) \ + ETSLOT(NAME, as_buffer.SLOT, FUNCTION, WRAPPER, DOC) #define AMSLOT(NAME, SLOT, FUNCTION, WRAPPER, DOC) \ ETSLOT(NAME, as_async.SLOT, FUNCTION, WRAPPER, DOC) #define SQSLOT(NAME, SLOT, FUNCTION, WRAPPER, DOC) \ @@ -9062,6 +9244,13 @@ static pytype_slotdef slotdefs[] = { "Create and return new object. See help(type) for accurate signature."), TPSLOT(__del__, tp_finalize, slot_tp_finalize, (wrapperfunc)wrap_del, ""), + BUFSLOT(__buffer__, bf_getbuffer, slot_bf_getbuffer, wrap_buffer, + "__buffer__($self, flags, /)\n--\n\n" + "Return a buffer object that exposes the underlying memory of the object."), + BUFSLOT(__release_buffer__, bf_releasebuffer, slot_bf_releasebuffer, wrap_releasebuffer, + "__release_buffer__($self, /)\n--\n\n" + "Release the buffer object that exposes the underlying memory of the object."), + AMSLOT(__await__, am_await, slot_am_await, wrap_unaryfunc, "__await__($self, /)\n--\n\nReturn an iterator to be used in await expression."), AMSLOT(__aiter__, am_aiter, slot_am_aiter, wrap_unaryfunc, @@ -9208,8 +9397,12 @@ slotptr(PyTypeObject *type, int ioffset) /* Note: this depends on the order of the members of PyHeapTypeObject! */ assert(offset >= 0); - assert((size_t)offset < offsetof(PyHeapTypeObject, as_buffer)); - if ((size_t)offset >= offsetof(PyHeapTypeObject, as_sequence)) { + assert((size_t)offset < offsetof(PyHeapTypeObject, ht_name)); + if ((size_t)offset >= offsetof(PyHeapTypeObject, as_buffer)) { + ptr = (char *)type->tp_as_buffer; + offset -= offsetof(PyHeapTypeObject, as_buffer); + } + else if ((size_t)offset >= offsetof(PyHeapTypeObject, as_sequence)) { ptr = (char *)type->tp_as_sequence; offset -= offsetof(PyHeapTypeObject, as_sequence); } |