The weak reference implementation, separated from the weakref module.
This commit is contained in:
Fred Drake
parent
bb9fa21cfe
commit
8844d5264f
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@ -0,0 +1,50 @@
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/* Weak references objects for Python. */
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#ifndef Py_WEAKREFOBJECT_H
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#define Py_WEAKREFOBJECT_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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typedef struct _PyWeakReference PyWeakReference;
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struct _PyWeakReference {
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PyObject_HEAD
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PyObject *wr_object;
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PyObject *wr_callback;
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long hash;
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PyWeakReference *wr_prev;
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PyWeakReference *wr_next;
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};
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extern DL_IMPORT(PyTypeObject) _PyWeakref_RefType;
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extern DL_IMPORT(PyTypeObject) _PyWeakref_ProxyType;
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extern DL_IMPORT(PyTypeObject) _PyWeakref_CallableProxyType;
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extern DL_IMPORT(PyObject *) PyErr_ReferenceError;
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#define PyWeakref_CheckRef(op) \
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((op)->ob_type == &_PyWeakref_RefType)
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#define PyWeakref_CheckProxy(op) \
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(((op)->ob_type == &_PyWeakref_ProxyType) || \
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((op)->ob_type == &_PyWeakref_CallableProxyType))
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#define PyWeakref_Check(op) \
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(PyWeakref_CheckRef(op) || PyWeakref_CheckProxy(op))
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extern DL_IMPORT(PyObject *) PyWeakref_NewRef(PyObject *ob,
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PyObject *callback);
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extern DL_IMPORT(PyObject *) PyWeakref_NewProxy(PyObject *ob,
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PyObject *callback);
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extern DL_IMPORT(PyObject *) PyWeakref_GetObject(PyObject *ref);
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extern DL_IMPORT(long) _PyWeakref_GetWeakrefCount(PyWeakReference *head);
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#define PyWeakref_GET_OBJECT(ref) (((PyWeakReference *)(ref))->wr_object)
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#ifdef __cplusplus
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}
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#endif
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#endif /* !Py_WEAKREFOBJECT_H */
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@ -0,0 +1,715 @@
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#include "Python.h"
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#include "structmember.h"
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#define GET_WEAKREFS_LISTPTR(o) \
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((PyWeakReference **) PyObject_GET_WEAKREFS_LISTPTR(o))
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static PyWeakReference *
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free_list = NULL;
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long
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_PyWeakref_GetWeakrefCount(PyWeakReference *head)
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{
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long count = 0;
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while (head != NULL) {
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++count;
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head = head->wr_next;
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}
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return count;
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}
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static PyWeakReference *
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new_weakref(void)
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{
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PyWeakReference *result;
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if (free_list != NULL) {
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result = free_list;
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free_list = result->wr_next;
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result->ob_type = &_PyWeakref_RefType;
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_Py_NewReference((PyObject *)result);
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}
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else {
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result = PyObject_GC_New(PyWeakReference, &_PyWeakref_RefType);
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}
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if (result)
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result->hash = -1;
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return result;
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}
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/* This function clears the passed-in reference and removes it from the
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* list of weak references for the referent. This is the only code that
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* removes an item from the doubly-linked list of weak references for an
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* object; it is also responsible for clearing the callback slot.
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*/
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static void
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clear_weakref(PyWeakReference *self)
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{
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PyObject *callback = self->wr_callback;
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if (PyWeakref_GET_OBJECT(self) != Py_None) {
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PyWeakReference **list = GET_WEAKREFS_LISTPTR(
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PyWeakref_GET_OBJECT(self));
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if (*list == self)
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*list = self->wr_next;
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self->wr_object = Py_None;
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self->wr_callback = NULL;
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if (self->wr_prev != NULL)
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self->wr_prev->wr_next = self->wr_next;
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if (self->wr_next != NULL)
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self->wr_next->wr_prev = self->wr_prev;
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self->wr_prev = NULL;
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self->wr_next = NULL;
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Py_XDECREF(callback);
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}
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}
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static void
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weakref_dealloc(PyWeakReference *self)
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{
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PyObject_GC_UnTrack((PyObject *)self);
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clear_weakref(self);
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self->wr_next = free_list;
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free_list = self;
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}
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static int
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gc_traverse(PyWeakReference *self, visitproc visit, void *arg)
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{
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if (self->wr_callback != NULL)
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return visit(self->wr_callback, arg);
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return 0;
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}
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static int
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gc_clear(PyWeakReference *self)
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{
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clear_weakref(self);
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return 0;
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}
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static PyObject *
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weakref_call(PyWeakReference *self, PyObject *args, PyObject *kw)
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{
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static char *argnames[] = {NULL};
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if (PyArg_ParseTupleAndKeywords(args, kw, ":__call__", argnames)) {
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PyObject *object = PyWeakref_GET_OBJECT(self);
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Py_INCREF(object);
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return (object);
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}
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return NULL;
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}
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static long
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weakref_hash(PyWeakReference *self)
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{
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if (self->hash != -1)
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return self->hash;
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if (PyWeakref_GET_OBJECT(self) == Py_None) {
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PyErr_SetString(PyExc_TypeError, "weak object has gone away");
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return -1;
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}
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self->hash = PyObject_Hash(PyWeakref_GET_OBJECT(self));
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return self->hash;
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}
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static PyObject *
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weakref_repr(PyWeakReference *self)
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{
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char buffer[256];
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if (PyWeakref_GET_OBJECT(self) == Py_None) {
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sprintf(buffer, "<weakref at %lx; dead>",
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(long)(self));
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}
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else {
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sprintf(buffer, "<weakref at %#lx; to '%s' at %#lx>",
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(long)(self), PyWeakref_GET_OBJECT(self)->ob_type->tp_name,
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(long)(PyWeakref_GET_OBJECT(self)));
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}
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return PyString_FromString(buffer);
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}
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/* Weak references only support equality, not ordering. Two weak references
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are equal if the underlying objects are equal. If the underlying object has
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gone away, they are equal if they are identical. */
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static PyObject *
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weakref_richcompare(PyWeakReference* self, PyWeakReference* other, int op)
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{
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if (op != Py_EQ || self->ob_type != other->ob_type) {
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Py_INCREF(Py_NotImplemented);
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return Py_NotImplemented;
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}
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if (PyWeakref_GET_OBJECT(self) == Py_None
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|| PyWeakref_GET_OBJECT(other) == Py_None) {
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PyObject *res = self==other ? Py_True : Py_False;
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Py_INCREF(res);
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return res;
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}
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return PyObject_RichCompare(PyWeakref_GET_OBJECT(self),
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PyWeakref_GET_OBJECT(other), op);
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}
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PyTypeObject
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_PyWeakref_RefType = {
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PyObject_HEAD_INIT(&PyType_Type)
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0,
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"weakref",
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sizeof(PyWeakReference),
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0,
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(destructor)weakref_dealloc,/*tp_dealloc*/
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0, /*tp_print*/
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0, /*tp_getattr*/
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0, /*tp_setattr*/
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0, /*tp_compare*/
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(reprfunc)weakref_repr, /*tp_repr*/
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0, /*tp_as_number*/
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0, /*tp_as_sequence*/
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0, /*tp_as_mapping*/
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(hashfunc)weakref_hash, /*tp_hash*/
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(ternaryfunc)weakref_call, /*tp_call*/
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0, /*tp_str*/
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0, /*tp_getattro*/
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0, /*tp_setattro*/
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0, /*tp_as_buffer*/
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Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_HAVE_RICHCOMPARE,
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0, /*tp_doc*/
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(traverseproc)gc_traverse, /*tp_traverse*/
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(inquiry)gc_clear, /*tp_clear*/
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(richcmpfunc)weakref_richcompare, /*tp_richcompare*/
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0, /*tp_weaklistoffset*/
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};
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static int
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proxy_checkref(PyWeakReference *proxy)
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{
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if (PyWeakref_GET_OBJECT(proxy) == Py_None) {
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PyErr_SetString(PyExc_ReferenceError,
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"weakly-referenced object no longer exists");
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return 0;
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}
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return 1;
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}
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#define WRAP_UNARY(method, generic) \
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static PyObject * \
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method(PyWeakReference *proxy) { \
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if (!proxy_checkref(proxy)) { \
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return NULL; \
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} \
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return generic(PyWeakref_GET_OBJECT(proxy)); \
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}
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#define WRAP_BINARY(method, generic) \
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static PyObject * \
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method(PyWeakReference *proxy, PyObject *v) { \
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if (!proxy_checkref(proxy)) { \
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return NULL; \
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} \
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return generic(PyWeakref_GET_OBJECT(proxy), v); \
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}
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#define WRAP_TERNARY(method, generic) \
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static PyObject * \
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method(PyWeakReference *proxy, PyObject *v, PyObject *w) { \
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if (!proxy_checkref(proxy)) { \
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return NULL; \
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} \
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return generic(PyWeakref_GET_OBJECT(proxy), v, w); \
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}
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/* direct slots */
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WRAP_BINARY(proxy_getattr, PyObject_GetAttr)
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WRAP_UNARY(proxy_str, PyObject_Str)
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WRAP_TERNARY(proxy_call, PyEval_CallObjectWithKeywords)
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static int
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proxy_print(PyWeakReference *proxy, FILE *fp, int flags)
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{
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if (!proxy_checkref(proxy))
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return -1;
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return PyObject_Print(PyWeakref_GET_OBJECT(proxy), fp, flags);
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}
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static PyObject *
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proxy_repr(PyWeakReference *proxy)
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{
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char buf[160];
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sprintf(buf, "<weakref at %p to %.100s at %p>", proxy,
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PyWeakref_GET_OBJECT(proxy)->ob_type->tp_name,
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PyWeakref_GET_OBJECT(proxy));
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return PyString_FromString(buf);
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}
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static int
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proxy_setattr(PyWeakReference *proxy, PyObject *name, PyObject *value)
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{
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if (!proxy_checkref(proxy))
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return -1;
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return PyObject_SetAttr(PyWeakref_GET_OBJECT(proxy), name, value);
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}
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static int
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proxy_compare(PyWeakReference *proxy, PyObject *v)
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{
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if (!proxy_checkref(proxy))
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return -1;
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return PyObject_Compare(PyWeakref_GET_OBJECT(proxy), v);
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}
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/* number slots */
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WRAP_BINARY(proxy_add, PyNumber_Add)
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WRAP_BINARY(proxy_sub, PyNumber_Subtract)
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WRAP_BINARY(proxy_mul, PyNumber_Multiply)
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WRAP_BINARY(proxy_div, PyNumber_Divide)
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WRAP_BINARY(proxy_mod, PyNumber_Remainder)
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WRAP_BINARY(proxy_divmod, PyNumber_Divmod)
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WRAP_TERNARY(proxy_pow, PyNumber_Power)
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WRAP_UNARY(proxy_neg, PyNumber_Negative)
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WRAP_UNARY(proxy_pos, PyNumber_Positive)
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WRAP_UNARY(proxy_abs, PyNumber_Absolute)
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WRAP_UNARY(proxy_invert, PyNumber_Invert)
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WRAP_BINARY(proxy_lshift, PyNumber_Lshift)
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WRAP_BINARY(proxy_rshift, PyNumber_Rshift)
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WRAP_BINARY(proxy_and, PyNumber_And)
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WRAP_BINARY(proxy_xor, PyNumber_Xor)
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WRAP_BINARY(proxy_or, PyNumber_Or)
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WRAP_UNARY(proxy_int, PyNumber_Int)
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WRAP_UNARY(proxy_long, PyNumber_Long)
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WRAP_UNARY(proxy_float, PyNumber_Float)
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WRAP_BINARY(proxy_iadd, PyNumber_InPlaceAdd)
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WRAP_BINARY(proxy_isub, PyNumber_InPlaceSubtract)
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WRAP_BINARY(proxy_imul, PyNumber_InPlaceMultiply)
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WRAP_BINARY(proxy_idiv, PyNumber_InPlaceDivide)
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WRAP_BINARY(proxy_imod, PyNumber_InPlaceRemainder)
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WRAP_TERNARY(proxy_ipow, PyNumber_InPlacePower)
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WRAP_BINARY(proxy_ilshift, PyNumber_InPlaceLshift)
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WRAP_BINARY(proxy_irshift, PyNumber_InPlaceRshift)
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WRAP_BINARY(proxy_iand, PyNumber_InPlaceAnd)
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WRAP_BINARY(proxy_ixor, PyNumber_InPlaceXor)
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WRAP_BINARY(proxy_ior, PyNumber_InPlaceOr)
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static int
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proxy_nonzero(PyWeakReference *proxy)
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{
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PyObject *o = PyWeakref_GET_OBJECT(proxy);
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if (!proxy_checkref(proxy))
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return 1;
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if (o->ob_type->tp_as_number &&
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o->ob_type->tp_as_number->nb_nonzero)
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return (*o->ob_type->tp_as_number->nb_nonzero)(o);
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else
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return 1;
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}
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/* sequence slots */
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static PyObject *
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proxy_slice(PyWeakReference *proxy, int i, int j)
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{
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if (!proxy_checkref(proxy))
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return NULL;
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return PySequence_GetSlice(PyWeakref_GET_OBJECT(proxy), i, j);
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}
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static int
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proxy_ass_slice(PyWeakReference *proxy, int i, int j, PyObject *value)
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{
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if (!proxy_checkref(proxy))
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return -1;
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return PySequence_SetSlice(PyWeakref_GET_OBJECT(proxy), i, j, value);
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}
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static int
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proxy_contains(PyWeakReference *proxy, PyObject *value)
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{
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if (!proxy_checkref(proxy))
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return -1;
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return PySequence_Contains(PyWeakref_GET_OBJECT(proxy), value);
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}
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/* mapping slots */
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static int
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proxy_length(PyWeakReference *proxy)
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{
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if (!proxy_checkref(proxy))
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return -1;
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return PyObject_Length(PyWeakref_GET_OBJECT(proxy));
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}
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WRAP_BINARY(proxy_getitem, PyObject_GetItem)
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static int
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proxy_setitem(PyWeakReference *proxy, PyObject *key, PyObject *value)
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{
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if (!proxy_checkref(proxy))
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return -1;
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return PyObject_SetItem(PyWeakref_GET_OBJECT(proxy), key, value);
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}
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static PyNumberMethods proxy_as_number = {
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(binaryfunc)proxy_add, /*nb_add*/
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(binaryfunc)proxy_sub, /*nb_subtract*/
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(binaryfunc)proxy_mul, /*nb_multiply*/
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(binaryfunc)proxy_div, /*nb_divide*/
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(binaryfunc)proxy_mod, /*nb_remainder*/
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(binaryfunc)proxy_divmod, /*nb_divmod*/
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(ternaryfunc)proxy_pow, /*nb_power*/
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(unaryfunc)proxy_neg, /*nb_negative*/
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(unaryfunc)proxy_pos, /*nb_positive*/
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(unaryfunc)proxy_abs, /*nb_absolute*/
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(inquiry)proxy_nonzero, /*nb_nonzero*/
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(unaryfunc)proxy_invert, /*nb_invert*/
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(binaryfunc)proxy_lshift, /*nb_lshift*/
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(binaryfunc)proxy_rshift, /*nb_rshift*/
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(binaryfunc)proxy_and, /*nb_and*/
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(binaryfunc)proxy_xor, /*nb_xor*/
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(binaryfunc)proxy_or, /*nb_or*/
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(coercion)0, /*nb_coerce*/
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(unaryfunc)proxy_int, /*nb_int*/
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(unaryfunc)proxy_long, /*nb_long*/
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(unaryfunc)proxy_float, /*nb_float*/
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(unaryfunc)0, /*nb_oct*/
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(unaryfunc)0, /*nb_hex*/
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(binaryfunc)proxy_iadd, /*nb_inplace_add*/
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(binaryfunc)proxy_isub, /*nb_inplace_subtract*/
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(binaryfunc)proxy_imul, /*nb_inplace_multiply*/
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(binaryfunc)proxy_idiv, /*nb_inplace_divide*/
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(binaryfunc)proxy_imod, /*nb_inplace_remainder*/
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(ternaryfunc)proxy_ipow, /*nb_inplace_power*/
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(binaryfunc)proxy_ilshift, /*nb_inplace_lshift*/
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(binaryfunc)proxy_irshift, /*nb_inplace_rshift*/
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(binaryfunc)proxy_iand, /*nb_inplace_and*/
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(binaryfunc)proxy_ixor, /*nb_inplace_xor*/
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(binaryfunc)proxy_ior, /*nb_inplace_or*/
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};
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static PySequenceMethods proxy_as_sequence = {
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(inquiry)proxy_length, /*sq_length*/
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0, /*sq_concat*/
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0, /*sq_repeat*/
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0, /*sq_item*/
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(intintargfunc)proxy_slice, /*sq_slice*/
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0, /*sq_ass_item*/
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(intintobjargproc)proxy_ass_slice, /*sq_ass_slice*/
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(objobjproc)proxy_contains, /* sq_contains */
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};
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static PyMappingMethods proxy_as_mapping = {
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(inquiry)proxy_length, /*mp_length*/
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(binaryfunc)proxy_getitem, /*mp_subscript*/
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(objobjargproc)proxy_setitem, /*mp_ass_subscript*/
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};
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||||
PyTypeObject
|
||||
_PyWeakref_ProxyType = {
|
||||
PyObject_HEAD_INIT(&PyType_Type)
|
||||
0,
|
||||
"weakproxy",
|
||||
sizeof(PyWeakReference),
|
||||
0,
|
||||
/* methods */
|
||||
(destructor)weakref_dealloc,/*tp_dealloc*/
|
||||
(printfunc)proxy_print, /*tp_print*/
|
||||
0, /*tp_getattr*/
|
||||
0, /*tp_setattr*/
|
||||
(cmpfunc)proxy_compare, /*tp_compare*/
|
||||
(unaryfunc)proxy_repr, /*tp_repr*/
|
||||
&proxy_as_number, /*tp_as_number*/
|
||||
&proxy_as_sequence, /*tp_as_sequence*/
|
||||
&proxy_as_mapping, /*tp_as_mapping*/
|
||||
0, /*tp_hash*/
|
||||
(ternaryfunc)0, /*tp_call*/
|
||||
(unaryfunc)proxy_str, /*tp_str*/
|
||||
(getattrofunc)proxy_getattr,/*tp_getattro*/
|
||||
(setattrofunc)proxy_setattr,/*tp_setattro*/
|
||||
0, /*tp_as_buffer*/
|
||||
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC
|
||||
|Py_TPFLAGS_CHECKTYPES, /*tp_flags*/
|
||||
0, /*tp_doc*/
|
||||
(traverseproc)gc_traverse, /*tp_traverse*/
|
||||
(inquiry)gc_clear, /*tp_clear*/
|
||||
};
|
||||
|
||||
|
||||
PyTypeObject
|
||||
_PyWeakref_CallableProxyType = {
|
||||
PyObject_HEAD_INIT(&PyType_Type)
|
||||
0,
|
||||
"weakcallableproxy",
|
||||
sizeof(PyWeakReference),
|
||||
0,
|
||||
/* methods */
|
||||
(destructor)weakref_dealloc,/*tp_dealloc*/
|
||||
(printfunc)proxy_print, /*tp_print*/
|
||||
0, /*tp_getattr*/
|
||||
0, /*tp_setattr*/
|
||||
(cmpfunc)proxy_compare, /*tp_compare*/
|
||||
(unaryfunc)proxy_repr, /*tp_repr*/
|
||||
&proxy_as_number, /*tp_as_number*/
|
||||
&proxy_as_sequence, /*tp_as_sequence*/
|
||||
&proxy_as_mapping, /*tp_as_mapping*/
|
||||
0, /*tp_hash*/
|
||||
(ternaryfunc)proxy_call, /*tp_call*/
|
||||
(unaryfunc)proxy_str, /*tp_str*/
|
||||
(getattrofunc)proxy_getattr,/*tp_getattro*/
|
||||
(setattrofunc)proxy_setattr,/*tp_setattro*/
|
||||
0, /*tp_as_buffer*/
|
||||
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC
|
||||
|Py_TPFLAGS_CHECKTYPES, /*tp_flags*/
|
||||
0, /*tp_doc*/
|
||||
(traverseproc)gc_traverse, /*tp_traverse*/
|
||||
(inquiry)gc_clear, /*tp_clear*/
|
||||
};
|
||||
|
||||
|
||||
/* Given the head of an object's list of weak references, extract the
|
||||
* two callback-less refs (ref and proxy). Used to determine if the
|
||||
* shared references exist and to determine the back link for newly
|
||||
* inserted references.
|
||||
*/
|
||||
static void
|
||||
get_basic_refs(PyWeakReference *head,
|
||||
PyWeakReference **refp, PyWeakReference **proxyp)
|
||||
{
|
||||
*refp = NULL;
|
||||
*proxyp = NULL;
|
||||
|
||||
if (head != NULL && head->wr_callback == NULL) {
|
||||
if (head->ob_type == &_PyWeakref_RefType) {
|
||||
*refp = head;
|
||||
head = head->wr_next;
|
||||
}
|
||||
if (head != NULL && head->wr_callback == NULL) {
|
||||
*proxyp = head;
|
||||
head = head->wr_next;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Insert 'newref' in the list after 'prev'. Both must be non-NULL. */
|
||||
static void
|
||||
insert_after(PyWeakReference *newref, PyWeakReference *prev)
|
||||
{
|
||||
newref->wr_prev = prev;
|
||||
newref->wr_next = prev->wr_next;
|
||||
if (prev->wr_next != NULL)
|
||||
prev->wr_next->wr_prev = newref;
|
||||
prev->wr_next = newref;
|
||||
}
|
||||
|
||||
/* Insert 'newref' at the head of the list; 'list' points to the variable
|
||||
* that stores the head.
|
||||
*/
|
||||
static void
|
||||
insert_head(PyWeakReference *newref, PyWeakReference **list)
|
||||
{
|
||||
PyWeakReference *next = *list;
|
||||
|
||||
newref->wr_prev = NULL;
|
||||
newref->wr_next = next;
|
||||
if (next != NULL)
|
||||
next->wr_prev = newref;
|
||||
*list = newref;
|
||||
}
|
||||
|
||||
|
||||
PyObject *
|
||||
PyWeakref_NewRef(PyObject *ob, PyObject *callback)
|
||||
{
|
||||
PyWeakReference *result = NULL;
|
||||
PyWeakReference **list;
|
||||
PyWeakReference *ref, *proxy;
|
||||
|
||||
if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) {
|
||||
PyErr_Format(PyExc_TypeError,
|
||||
"'%s' objects are not weakly referencable",
|
||||
ob->ob_type->tp_name);
|
||||
return NULL;
|
||||
}
|
||||
list = GET_WEAKREFS_LISTPTR(ob);
|
||||
get_basic_refs(*list, &ref, &proxy);
|
||||
if (callback == NULL || callback == Py_None)
|
||||
/* return existing weak reference if it exists */
|
||||
result = ref;
|
||||
if (result != NULL)
|
||||
Py_XINCREF(result);
|
||||
else {
|
||||
result = new_weakref();
|
||||
if (result != NULL) {
|
||||
Py_XINCREF(callback);
|
||||
result->wr_callback = callback;
|
||||
result->wr_object = ob;
|
||||
if (callback == NULL) {
|
||||
insert_head(result, list);
|
||||
}
|
||||
else {
|
||||
PyWeakReference *prev = (proxy == NULL) ? ref : proxy;
|
||||
|
||||
if (prev == NULL)
|
||||
insert_head(result, list);
|
||||
else
|
||||
insert_after(result, prev);
|
||||
}
|
||||
PyObject_GC_Track(result);
|
||||
}
|
||||
}
|
||||
return (PyObject *) result;
|
||||
}
|
||||
|
||||
|
||||
PyObject *
|
||||
PyWeakref_NewProxy(PyObject *ob, PyObject *callback)
|
||||
{
|
||||
PyWeakReference *result = NULL;
|
||||
PyWeakReference **list;
|
||||
PyWeakReference *ref, *proxy;
|
||||
|
||||
if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) {
|
||||
PyErr_Format(PyExc_TypeError,
|
||||
"'%s' objects are not weakly referencable",
|
||||
ob->ob_type->tp_name);
|
||||
return NULL;
|
||||
}
|
||||
list = GET_WEAKREFS_LISTPTR(ob);
|
||||
get_basic_refs(*list, &ref, &proxy);
|
||||
if (callback == NULL)
|
||||
/* attempt to return an existing weak reference if it exists */
|
||||
result = proxy;
|
||||
if (result != NULL)
|
||||
Py_XINCREF(result);
|
||||
else {
|
||||
result = new_weakref();
|
||||
if (result != NULL) {
|
||||
PyWeakReference *prev;
|
||||
|
||||
if (PyCallable_Check(ob))
|
||||
result->ob_type = &_PyWeakref_CallableProxyType;
|
||||
else
|
||||
result->ob_type = &_PyWeakref_ProxyType;
|
||||
result->wr_object = ob;
|
||||
Py_XINCREF(callback);
|
||||
result->wr_callback = callback;
|
||||
if (callback == NULL)
|
||||
prev = ref;
|
||||
else
|
||||
prev = (proxy == NULL) ? ref : proxy;
|
||||
|
||||
if (prev == NULL)
|
||||
insert_head(result, list);
|
||||
else
|
||||
insert_after(result, prev);
|
||||
PyObject_GC_Track(result);
|
||||
}
|
||||
}
|
||||
return (PyObject *) result;
|
||||
}
|
||||
|
||||
|
||||
PyObject *
|
||||
PyWeakref_GetObject(PyObject *ref)
|
||||
{
|
||||
if (ref == NULL || !PyWeakref_Check(ref)) {
|
||||
PyErr_BadInternalCall();
|
||||
return NULL;
|
||||
}
|
||||
return PyWeakref_GET_OBJECT(ref);
|
||||
}
|
||||
|
||||
|
||||
/* This is the implementation of the PyObject_ClearWeakRefs() function; it
|
||||
* is installed in the init_weakref() function. It is called by the
|
||||
* tp_dealloc handler to clear weak references.
|
||||
*
|
||||
* This iterates through the weak references for 'object' and calls callbacks
|
||||
* for those references which have one. It returns when all callbacks have
|
||||
* been attempted.
|
||||
*/
|
||||
void
|
||||
PyObject_ClearWeakRefs(PyObject *object)
|
||||
{
|
||||
PyWeakReference **list;
|
||||
|
||||
if (object == NULL
|
||||
|| !PyType_SUPPORTS_WEAKREFS(object->ob_type)
|
||||
|| object->ob_refcnt != 0) {
|
||||
PyErr_BadInternalCall();
|
||||
return;
|
||||
}
|
||||
list = GET_WEAKREFS_LISTPTR(object);
|
||||
/* Remove the callback-less basic and proxy references */
|
||||
if (*list != NULL && (*list)->wr_callback == NULL) {
|
||||
clear_weakref(*list);
|
||||
if (*list != NULL && (*list)->wr_callback == NULL)
|
||||
clear_weakref(*list);
|
||||
}
|
||||
if (*list != NULL) {
|
||||
int count = _PyWeakref_GetWeakrefCount(*list);
|
||||
|
||||
if (count == 1) {
|
||||
PyWeakReference *current = *list;
|
||||
PyObject *callback = current->wr_callback;
|
||||
PyObject *cbresult;
|
||||
|
||||
Py_INCREF(callback);
|
||||
clear_weakref(current);
|
||||
cbresult = PyObject_CallFunction(callback, "O", current);
|
||||
if (cbresult == NULL)
|
||||
PyErr_WriteUnraisable(callback);
|
||||
else
|
||||
Py_DECREF(cbresult);
|
||||
Py_DECREF(callback);
|
||||
}
|
||||
else {
|
||||
PyObject *tuple = PyTuple_New(count * 2);
|
||||
PyWeakReference *current = *list;
|
||||
int i = 0;
|
||||
|
||||
for (i = 0; i < count; ++i) {
|
||||
PyWeakReference *next = current->wr_next;
|
||||
|
||||
Py_INCREF(current);
|
||||
PyTuple_SET_ITEM(tuple, i * 2, (PyObject *) current);
|
||||
PyTuple_SET_ITEM(tuple, i * 2 + 1, current->wr_callback);
|
||||
current->wr_callback = NULL;
|
||||
next = current->wr_next;
|
||||
clear_weakref(current);
|
||||
current = next;
|
||||
}
|
||||
for (i = 0; i < count; ++i) {
|
||||
PyObject *current = PyTuple_GET_ITEM(tuple, i * 2);
|
||||
PyObject *callback = PyTuple_GET_ITEM(tuple, i * 2 + 1);
|
||||
PyObject *cbresult = PyObject_CallFunction(callback, "O",
|
||||
current);
|
||||
if (cbresult == NULL)
|
||||
PyErr_WriteUnraisable(callback);
|
||||
else
|
||||
Py_DECREF(cbresult);
|
||||
}
|
||||
Py_DECREF(tuple);
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue