[Python-checkins] CVS: python/dist/src/Objects dictobject.c,2.67,2.68

[Guido van Rossum]

Update of /cvsroot/python/python/dist/src/Objects
In directory slayer.i.sourceforge.net:/tmp/cvs-serv10552

Modified Files:
	dictobject.c 
Log Message:
Add popitem() -- SF patch #102733.


Index: dictobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/dictobject.c,v
retrieving revision 2.67
retrieving revision 2.68
diff -C2 -r2.67 -r2.68
*** dictobject.c	2000/11/30 19:30:19	2.67
--- dictobject.c	2000/12/12 22:02:18	2.68
***************
*** 1133,1136 ****
--- 1133,1188 ----
  }
  
+ static PyObject *
+ dict_popitem(dictobject *mp, PyObject *args)
+ {
+ 	int i = 0;
+ 	dictentry *ep;
+ 	PyObject *res;
+ 
+ 	if (!PyArg_NoArgs(args))
+ 		return NULL;
+ 	if (mp->ma_used == 0) {
+ 		PyErr_SetString(PyExc_KeyError,
+ 				"popitem(): dictionary is empty");
+ 		return NULL;
+ 	}
+ 	/* Set ep to "the first" dict entry with a value.  We abuse the hash
+ 	 * field of slot 0 to hold a search finger:
+ 	 * If slot 0 has a value, use slot 0.
+ 	 * Else slot 0 is being used to hold a search finger,
+ 	 * and we use its hash value as the first index to look.
+ 	 */
+ 	ep = &mp->ma_table[0];
+ 	if (ep->me_value == NULL) {
+ 		i = (int)ep->me_hash;
+ 		/* The hash field may be uninitialized trash, or it
+ 		 * may be a real hash value, or it may be a legit
+ 		 * search finger, or it may be a once-legit search
+ 		 * finger that's out of bounds now because it
+ 		 * wrapped around or the table shrunk -- simply
+ 		 * make sure it's in bounds now.
+ 		 */
+ 		if (i >= mp->ma_size || i < 1)
+ 			i = 1;	/* skip slot 0 */
+ 		while ((ep = &mp->ma_table[i])->me_value == NULL) {
+ 			i++;
+ 			if (i >= mp->ma_size)
+ 				i = 1;
+ 		}
+ 	}
+ 	res = PyTuple_New(2);
+ 	if (res != NULL) {
+ 		PyTuple_SET_ITEM(res, 0, ep->me_key);
+ 		PyTuple_SET_ITEM(res, 1, ep->me_value);
+ 		Py_INCREF(dummy);
+ 		ep->me_key = dummy;
+ 		ep->me_value = NULL;
+ 		mp->ma_used--;
+ 		assert(mp->ma_table[0].me_value == NULL);
+ 		mp->ma_table[0].me_hash = i + 1;  /* next place to start */
+ 	}
+ 	return res;
+ }
+ 
  static int
  dict_traverse(PyObject *op, visitproc visit, void *arg)
***************
*** 1168,1171 ****
--- 1220,1224 ----
  	{"get",         (PyCFunction)dict_get,          METH_VARARGS},
  	{"setdefault",  (PyCFunction)dict_setdefault,   METH_VARARGS},
+ 	{"popitem",	(PyCFunction)dict_popitem},
  	{NULL,		NULL}		/* sentinel */
  };