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fbd849f201
A cell contains a reference to a single PyObject. It could be implemented as a mutable, one-element sequence, but the separate type has less overhead.
115 lines
2.2 KiB
C
115 lines
2.2 KiB
C
/* Cell object implementation */
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#include "Python.h"
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PyObject *
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PyCell_New(PyObject *obj)
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{
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PyCellObject *op;
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op = (PyCellObject *)PyObject_New(PyCellObject, &PyCell_Type);
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op->ob_ref = obj;
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Py_XINCREF(obj);
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PyObject_GC_Init(op);
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return (PyObject *)op;
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}
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PyObject *
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PyCell_Get(PyObject *op)
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{
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if (!PyCell_Check(op)) {
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PyErr_BadInternalCall();
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return NULL;
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}
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Py_XINCREF(((PyCellObject*)op)->ob_ref);
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return PyCell_GET(op);
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}
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int
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PyCell_Set(PyObject *op, PyObject *obj)
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{
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if (!PyCell_Check(op)) {
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PyErr_BadInternalCall();
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return -1;
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}
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Py_XDECREF(((PyCellObject*)op)->ob_ref);
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Py_XINCREF(obj);
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PyCell_SET(op, obj);
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return 0;
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}
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static void
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cell_dealloc(PyCellObject *op)
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{
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PyObject_GC_Fini(op);
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Py_XDECREF(op->ob_ref);
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PyObject_Del(op);
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}
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static int
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cell_compare(PyCellObject *a, PyCellObject *b)
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{
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if (a->ob_ref == NULL) {
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if (b->ob_ref == NULL)
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return 0;
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return -1;
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} else if (b->ob_ref == NULL)
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return 1;
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return PyObject_Compare(a->ob_ref, b->ob_ref);
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}
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static PyObject *
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cell_repr(PyCellObject *op)
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{
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char buf[256];
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if (op->ob_ref == NULL)
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sprintf(buf, "<cell at %p: empty>", op);
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else
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sprintf(buf, "<cell at %p: %.80s object at %p>",
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op, op->ob_ref->ob_type->tp_name, op->ob_ref);
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return PyString_FromString(buf);
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}
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static int
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cell_traverse(PyCellObject *op, visitproc visit, void *arg)
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{
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if (op->ob_ref)
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return visit(op->ob_ref, arg);
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return 0;
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}
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static int
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cell_clear(PyCellObject *op)
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{
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op->ob_ref = NULL;
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return 0;
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}
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PyTypeObject PyCell_Type = {
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PyObject_HEAD_INIT(&PyType_Type)
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0,
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"cell",
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sizeof(PyCellObject) + PyGC_HEAD_SIZE,
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0,
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(destructor)cell_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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(cmpfunc)cell_compare, /* tp_compare */
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(reprfunc)cell_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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0, /* tp_hash */
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0, /* 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_GC, /* tp_flags */
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0, /* tp_doc */
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(traverseproc)cell_traverse, /* tp_traverse */
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(inquiry)cell_clear, /* tp_clear */
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};
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