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tupleobject.c

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Last change on this file was 3225, checked in by bird, 18 years ago
Python 2.5
File size: 19.7 KB

Line
1
2	/* Tuple object implementation */
3
4	#include "Python.h"
5
6	/* Speed optimization to avoid frequent malloc/free of small tuples */
7	#ifndef MAXSAVESIZE
8	#define MAXSAVESIZE 20 /* Largest tuple to save on free list */
9	#endif
10	#ifndef MAXSAVEDTUPLES
11	#define MAXSAVEDTUPLES 2000 /* Maximum number of tuples of each size to save */
12	#endif
13
14	#if MAXSAVESIZE > 0
15	/* Entries 1 up to MAXSAVESIZE are free lists, entry 0 is the empty
16	tuple () of which at most one instance will be allocated.
17	*/
18	static PyTupleObject *free_tuples[MAXSAVESIZE];
19	static int num_free_tuples[MAXSAVESIZE];
20	#endif
21	#ifdef COUNT_ALLOCS
22	int fast_tuple_allocs;
23	int tuple_zero_allocs;
24	#endif
25
26	PyObject *
27	PyTuple_New(register Py_ssize_t size)
28	{
29	register PyTupleObject *op;
30	Py_ssize_t i;
31	if (size < 0) {
32	PyErr_BadInternalCall();
33	return NULL;
34	}
35	#if MAXSAVESIZE > 0
36	if (size == 0 && free_tuples[0]) {
37	op = free_tuples[0];
38	Py_INCREF(op);
39	#ifdef COUNT_ALLOCS
40	tuple_zero_allocs++;
41	#endif
42	return (PyObject *) op;
43	}
44	if (size < MAXSAVESIZE && (op = free_tuples[size]) != NULL) {
45	free_tuples[size] = (PyTupleObject *) op->ob_item[0];
46	num_free_tuples[size]--;
47	#ifdef COUNT_ALLOCS
48	fast_tuple_allocs++;
49	#endif
50	/* Inline PyObject_InitVar */
51	#ifdef Py_TRACE_REFS
52	op->ob_size = size;
53	op->ob_type = &PyTuple_Type;
54	#endif
55	_Py_NewReference((PyObject *)op);
56	}
57	else
58	#endif
59	{
60	Py_ssize_t nbytes = size * sizeof(PyObject *);
61	/* Check for overflow */
62	if (nbytes / sizeof(PyObject *) != (size_t)size \|\|
63	(nbytes += sizeof(PyTupleObject) - sizeof(PyObject *))
64	<= 0)
65	{
66	return PyErr_NoMemory();
67	}
68	op = PyObject_GC_NewVar(PyTupleObject, &PyTuple_Type, size);
69	if (op == NULL)
70	return NULL;
71	}
72	for (i=0; i < size; i++)
73	op->ob_item[i] = NULL;
74	#if MAXSAVESIZE > 0
75	if (size == 0) {
76	free_tuples[0] = op;
77	++num_free_tuples[0];
78	Py_INCREF(op); /* extra INCREF so that this is never freed */
79	}
80	#endif
81	_PyObject_GC_TRACK(op);
82	return (PyObject *) op;
83	}
84
85	Py_ssize_t
86	PyTuple_Size(register PyObject *op)
87	{
88	if (!PyTuple_Check(op)) {
89	PyErr_BadInternalCall();
90	return -1;
91	}
92	else
93	return ((PyTupleObject *)op)->ob_size;
94	}
95
96	PyObject *
97	PyTuple_GetItem(register PyObject *op, register Py_ssize_t i)
98	{
99	if (!PyTuple_Check(op)) {
100	PyErr_BadInternalCall();
101	return NULL;
102	}
103	if (i < 0 \|\| i >= ((PyTupleObject *)op) -> ob_size) {
104	PyErr_SetString(PyExc_IndexError, "tuple index out of range");
105	return NULL;
106	}
107	return ((PyTupleObject *)op) -> ob_item[i];
108	}
109
110	int
111	PyTuple_SetItem(register PyObject op, register Py_ssize_t i, PyObject newitem)
112	{
113	register PyObject *olditem;
114	register PyObject **p;
115	if (!PyTuple_Check(op) \|\| op->ob_refcnt != 1) {
116	Py_XDECREF(newitem);
117	PyErr_BadInternalCall();
118	return -1;
119	}
120	if (i < 0 \|\| i >= ((PyTupleObject *)op) -> ob_size) {
121	Py_XDECREF(newitem);
122	PyErr_SetString(PyExc_IndexError,
123	"tuple assignment index out of range");
124	return -1;
125	}
126	p = ((PyTupleObject *)op) -> ob_item + i;
127	olditem = *p;
128	*p = newitem;
129	Py_XDECREF(olditem);
130	return 0;
131	}
132
133	PyObject *
134	PyTuple_Pack(Py_ssize_t n, ...)
135	{
136	Py_ssize_t i;
137	PyObject *o;
138	PyObject *result;
139	PyObject **items;
140	va_list vargs;
141
142	va_start(vargs, n);
143	result = PyTuple_New(n);
144	if (result == NULL)
145	return NULL;
146	items = ((PyTupleObject *)result)->ob_item;
147	for (i = 0; i < n; i++) {
148	o = va_arg(vargs, PyObject *);
149	Py_INCREF(o);
150	items[i] = o;
151	}
152	va_end(vargs);
153	return result;
154	}
155
156
157	/* Methods */
158
159	static void
160	tupledealloc(register PyTupleObject *op)
161	{
162	register Py_ssize_t i;
163	register Py_ssize_t len = op->ob_size;
164	PyObject_GC_UnTrack(op);
165	Py_TRASHCAN_SAFE_BEGIN(op)
166	if (len > 0) {
167	i = len;
168	while (--i >= 0)
169	Py_XDECREF(op->ob_item[i]);
170	#if MAXSAVESIZE > 0
171	if (len < MAXSAVESIZE &&
172	num_free_tuples[len] < MAXSAVEDTUPLES &&
173	op->ob_type == &PyTuple_Type)
174	{
175	op->ob_item[0] = (PyObject *) free_tuples[len];
176	num_free_tuples[len]++;
177	free_tuples[len] = op;
178	goto done; /* return */
179	}
180	#endif
181	}
182	op->ob_type->tp_free((PyObject *)op);
183	done:
184	Py_TRASHCAN_SAFE_END(op)
185	}
186
187	static int
188	tupleprint(PyTupleObject op, FILE fp, int flags)
189	{
190	Py_ssize_t i;
191	fprintf(fp, "(");
192	for (i = 0; i < op->ob_size; i++) {
193	if (i > 0)
194	fprintf(fp, ", ");
195	if (PyObject_Print(op->ob_item[i], fp, 0) != 0)
196	return -1;
197	}
198	if (op->ob_size == 1)
199	fprintf(fp, ",");
200	fprintf(fp, ")");
201	return 0;
202	}
203
204	static PyObject *
205	tuplerepr(PyTupleObject *v)
206	{
207	Py_ssize_t i, n;
208	PyObject s, temp;
209	PyObject pieces, result = NULL;
210
211	n = v->ob_size;
212	if (n == 0)
213	return PyString_FromString("()");
214
215	pieces = PyTuple_New(n);
216	if (pieces == NULL)
217	return NULL;
218
219	/* Do repr() on each element. */
220	for (i = 0; i < n; ++i) {
221	s = PyObject_Repr(v->ob_item[i]);
222	if (s == NULL)
223	goto Done;
224	PyTuple_SET_ITEM(pieces, i, s);
225	}
226
227	/* Add "()" decorations to the first and last items. */
228	assert(n > 0);
229	s = PyString_FromString("(");
230	if (s == NULL)
231	goto Done;
232	temp = PyTuple_GET_ITEM(pieces, 0);
233	PyString_ConcatAndDel(&s, temp);
234	PyTuple_SET_ITEM(pieces, 0, s);
235	if (s == NULL)
236	goto Done;
237
238	s = PyString_FromString(n == 1 ? ",)" : ")");
239	if (s == NULL)
240	goto Done;
241	temp = PyTuple_GET_ITEM(pieces, n-1);
242	PyString_ConcatAndDel(&temp, s);
243	PyTuple_SET_ITEM(pieces, n-1, temp);
244	if (temp == NULL)
245	goto Done;
246
247	/* Paste them all together with ", " between. */
248	s = PyString_FromString(", ");
249	if (s == NULL)
250	goto Done;
251	result = _PyString_Join(s, pieces);
252	Py_DECREF(s);
253
254	Done:
255	Py_DECREF(pieces);
256	return result;
257	}
258
259	/* The addend 82520, was selected from the range(0, 1000000) for
260	generating the greatest number of prime multipliers for tuples
261	upto length eight:
262
263	1082527, 1165049, 1082531, 1165057, 1247581, 1330103, 1082533,
264	1330111, 1412633, 1165069, 1247599, 1495177, 1577699
265	*/
266
267	static long
268	tuplehash(PyTupleObject *v)
269	{
270	register long x, y;
271	register Py_ssize_t len = v->ob_size;
272	register PyObject **p;
273	long mult = 1000003L;
274	x = 0x345678L;
275	p = v->ob_item;
276	while (--len >= 0) {
277	y = PyObject_Hash(*p++);
278	if (y == -1)
279	return -1;
280	x = (x ^ y) * mult;
281	/* the cast might truncate len; that doesn't change hash stability */
282	mult += (long)(82520L + len + len);
283	}
284	x += 97531L;
285	if (x == -1)
286	x = -2;
287	return x;
288	}
289
290	static Py_ssize_t
291	tuplelength(PyTupleObject *a)
292	{
293	return a->ob_size;
294	}
295
296	static int
297	tuplecontains(PyTupleObject a, PyObject el)
298	{
299	Py_ssize_t i;
300	int cmp;
301
302	for (i = 0, cmp = 0 ; cmp == 0 && i < a->ob_size; ++i)
303	cmp = PyObject_RichCompareBool(el, PyTuple_GET_ITEM(a, i),
304	Py_EQ);
305	return cmp;
306	}
307
308	static PyObject *
309	tupleitem(register PyTupleObject *a, register Py_ssize_t i)
310	{
311	if (i < 0 \|\| i >= a->ob_size) {
312	PyErr_SetString(PyExc_IndexError, "tuple index out of range");
313	return NULL;
314	}
315	Py_INCREF(a->ob_item[i]);
316	return a->ob_item[i];
317	}
318
319	static PyObject *
320	tupleslice(register PyTupleObject *a, register Py_ssize_t ilow,
321	register Py_ssize_t ihigh)
322	{
323	register PyTupleObject *np;
324	PyObject src, dest;
325	register Py_ssize_t i;
326	Py_ssize_t len;
327	if (ilow < 0)
328	ilow = 0;
329	if (ihigh > a->ob_size)
330	ihigh = a->ob_size;
331	if (ihigh < ilow)
332	ihigh = ilow;
333	if (ilow == 0 && ihigh == a->ob_size && PyTuple_CheckExact(a)) {
334	Py_INCREF(a);
335	return (PyObject *)a;
336	}
337	len = ihigh - ilow;
338	np = (PyTupleObject *)PyTuple_New(len);
339	if (np == NULL)
340	return NULL;
341	src = a->ob_item + ilow;
342	dest = np->ob_item;
343	for (i = 0; i < len; i++) {
344	PyObject *v = src[i];
345	Py_INCREF(v);
346	dest[i] = v;
347	}
348	return (PyObject *)np;
349	}
350
351	PyObject *
352	PyTuple_GetSlice(PyObject *op, Py_ssize_t i, Py_ssize_t j)
353	{
354	if (op == NULL \|\| !PyTuple_Check(op)) {
355	PyErr_BadInternalCall();
356	return NULL;
357	}
358	return tupleslice((PyTupleObject *)op, i, j);
359	}
360
361	static PyObject *
362	tupleconcat(register PyTupleObject a, register PyObject bb)
363	{
364	register Py_ssize_t size;
365	register Py_ssize_t i;
366	PyObject src, dest;
367	PyTupleObject *np;
368	if (!PyTuple_Check(bb)) {
369	PyErr_Format(PyExc_TypeError,
370	"can only concatenate tuple (not \"%.200s\") to tuple",
371	bb->ob_type->tp_name);
372	return NULL;
373	}
374	#define b ((PyTupleObject *)bb)
375	size = a->ob_size + b->ob_size;
376	if (size < 0)
377	return PyErr_NoMemory();
378	np = (PyTupleObject *) PyTuple_New(size);
379	if (np == NULL) {
380	return NULL;
381	}
382	src = a->ob_item;
383	dest = np->ob_item;
384	for (i = 0; i < a->ob_size; i++) {
385	PyObject *v = src[i];
386	Py_INCREF(v);
387	dest[i] = v;
388	}
389	src = b->ob_item;
390	dest = np->ob_item + a->ob_size;
391	for (i = 0; i < b->ob_size; i++) {
392	PyObject *v = src[i];
393	Py_INCREF(v);
394	dest[i] = v;
395	}
396	return (PyObject *)np;
397	#undef b
398	}
399
400	static PyObject *
401	tuplerepeat(PyTupleObject *a, Py_ssize_t n)
402	{
403	Py_ssize_t i, j;
404	Py_ssize_t size;
405	PyTupleObject *np;
406	PyObject p, items;
407	if (n < 0)
408	n = 0;
409	if (a->ob_size == 0 \|\| n == 1) {
410	if (PyTuple_CheckExact(a)) {
411	/* Since tuples are immutable, we can return a shared
412	copy in this case */
413	Py_INCREF(a);
414	return (PyObject *)a;
415	}
416	if (a->ob_size == 0)
417	return PyTuple_New(0);
418	}
419	size = a->ob_size * n;
420	if (size/a->ob_size != n)
421	return PyErr_NoMemory();
422	np = (PyTupleObject *) PyTuple_New(size);
423	if (np == NULL)
424	return NULL;
425	p = np->ob_item;
426	items = a->ob_item;
427	for (i = 0; i < n; i++) {
428	for (j = 0; j < a->ob_size; j++) {
429	*p = items[j];
430	Py_INCREF(*p);
431	p++;
432	}
433	}
434	return (PyObject *) np;
435	}
436
437	static int
438	tupletraverse(PyTupleObject o, visitproc visit, void arg)
439	{
440	Py_ssize_t i;
441
442	for (i = o->ob_size; --i >= 0; )
443	Py_VISIT(o->ob_item[i]);
444	return 0;
445	}
446
447	static PyObject *
448	tuplerichcompare(PyObject v, PyObject w, int op)
449	{
450	PyTupleObject vt, wt;
451	Py_ssize_t i;
452	Py_ssize_t vlen, wlen;
453
454	if (!PyTuple_Check(v) \|\| !PyTuple_Check(w)) {
455	Py_INCREF(Py_NotImplemented);
456	return Py_NotImplemented;
457	}
458
459	vt = (PyTupleObject *)v;
460	wt = (PyTupleObject *)w;
461
462	vlen = vt->ob_size;
463	wlen = wt->ob_size;
464
465	/* Note: the corresponding code for lists has an "early out" test
466	* here when op is EQ or NE and the lengths differ. That pays there,
467	* but Tim was unable to find any real code where EQ/NE tuple
468	* compares don't have the same length, so testing for it here would
469	* have cost without benefit.
470	*/
471
472	/* Search for the first index where items are different.
473	* Note that because tuples are immutable, it's safe to reuse
474	* vlen and wlen across the comparison calls.
475	*/
476	for (i = 0; i < vlen && i < wlen; i++) {
477	int k = PyObject_RichCompareBool(vt->ob_item[i],
478	wt->ob_item[i], Py_EQ);
479	if (k < 0)
480	return NULL;
481	if (!k)
482	break;
483	}
484
485	if (i >= vlen \|\| i >= wlen) {
486	/* No more items to compare -- compare sizes */
487	int cmp;
488	PyObject *res;
489	switch (op) {
490	case Py_LT: cmp = vlen < wlen; break;
491	case Py_LE: cmp = vlen <= wlen; break;
492	case Py_EQ: cmp = vlen == wlen; break;
493	case Py_NE: cmp = vlen != wlen; break;
494	case Py_GT: cmp = vlen > wlen; break;
495	case Py_GE: cmp = vlen >= wlen; break;
496	default: return NULL; /* cannot happen */
497	}
498	if (cmp)
499	res = Py_True;
500	else
501	res = Py_False;
502	Py_INCREF(res);
503	return res;
504	}
505
506	/* We have an item that differs -- shortcuts for EQ/NE */
507	if (op == Py_EQ) {
508	Py_INCREF(Py_False);
509	return Py_False;
510	}
511	if (op == Py_NE) {
512	Py_INCREF(Py_True);
513	return Py_True;
514	}
515
516	/* Compare the final item again using the proper operator */
517	return PyObject_RichCompare(vt->ob_item[i], wt->ob_item[i], op);
518	}
519
520	static PyObject *
521	tuple_subtype_new(PyTypeObject type, PyObject args, PyObject *kwds);
522
523	static PyObject *
524	tuple_new(PyTypeObject type, PyObject args, PyObject *kwds)
525	{
526	PyObject *arg = NULL;
527	static char *kwlist[] = {"sequence", 0};
528
529	if (type != &PyTuple_Type)
530	return tuple_subtype_new(type, args, kwds);
531	if (!PyArg_ParseTupleAndKeywords(args, kwds, "\|O:tuple", kwlist, &arg))
532	return NULL;
533
534	if (arg == NULL)
535	return PyTuple_New(0);
536	else
537	return PySequence_Tuple(arg);
538	}
539
540	static PyObject *
541	tuple_subtype_new(PyTypeObject type, PyObject args, PyObject *kwds)
542	{
543	PyObject tmp, newobj, *item;
544	Py_ssize_t i, n;
545
546	assert(PyType_IsSubtype(type, &PyTuple_Type));
547	tmp = tuple_new(&PyTuple_Type, args, kwds);
548	if (tmp == NULL)
549	return NULL;
550	assert(PyTuple_Check(tmp));
551	newobj = type->tp_alloc(type, n = PyTuple_GET_SIZE(tmp));
552	if (newobj == NULL)
553	return NULL;
554	for (i = 0; i < n; i++) {
555	item = PyTuple_GET_ITEM(tmp, i);
556	Py_INCREF(item);
557	PyTuple_SET_ITEM(newobj, i, item);
558	}
559	Py_DECREF(tmp);
560	return newobj;
561	}
562
563	PyDoc_STRVAR(tuple_doc,
564	"tuple() -> an empty tuple\n"
565	"tuple(sequence) -> tuple initialized from sequence's items\n"
566	"\n"
567	"If the argument is a tuple, the return value is the same object.");
568
569	static PySequenceMethods tuple_as_sequence = {
570	(lenfunc)tuplelength, /* sq_length */
571	(binaryfunc)tupleconcat, /* sq_concat */
572	(ssizeargfunc)tuplerepeat, /* sq_repeat */
573	(ssizeargfunc)tupleitem, /* sq_item */
574	(ssizessizeargfunc)tupleslice, /* sq_slice */
575	0, /* sq_ass_item */
576	0, /* sq_ass_slice */
577	(objobjproc)tuplecontains, /* sq_contains */
578	};
579
580	static PyObject*
581	tuplesubscript(PyTupleObject* self, PyObject* item)
582	{
583	if (PyIndex_Check(item)) {
584	Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);
585	if (i == -1 && PyErr_Occurred())
586	return NULL;
587	if (i < 0)
588	i += PyTuple_GET_SIZE(self);
589	return tupleitem(self, i);
590	}
591	else if (PySlice_Check(item)) {
592	Py_ssize_t start, stop, step, slicelength, cur, i;
593	PyObject* result;
594	PyObject* it;
595	PyObject src, dest;
596
597	if (PySlice_GetIndicesEx((PySliceObject*)item,
598	PyTuple_GET_SIZE(self),
599	&start, &stop, &step, &slicelength) < 0) {
600	return NULL;
601	}
602
603	if (slicelength <= 0) {
604	return PyTuple_New(0);
605	}
606	else {
607	result = PyTuple_New(slicelength);
608	if (!result) return NULL;
609
610	src = self->ob_item;
611	dest = ((PyTupleObject *)result)->ob_item;
612	for (cur = start, i = 0; i < slicelength;
613	cur += step, i++) {
614	it = src[cur];
615	Py_INCREF(it);
616	dest[i] = it;
617	}
618
619	return result;
620	}
621	}
622	else {
623	PyErr_SetString(PyExc_TypeError,
624	"tuple indices must be integers");
625	return NULL;
626	}
627	}
628
629	static PyObject *
630	tuple_getnewargs(PyTupleObject *v)
631	{
632	return Py_BuildValue("(N)", tupleslice(v, 0, v->ob_size));
633
634	}
635
636	static PyMethodDef tuple_methods[] = {
637	{"__getnewargs__", (PyCFunction)tuple_getnewargs, METH_NOARGS},
638	{NULL, NULL} /* sentinel */
639	};
640
641	static PyMappingMethods tuple_as_mapping = {
642	(lenfunc)tuplelength,
643	(binaryfunc)tuplesubscript,
644	0
645	};
646
647	static PyObject tuple_iter(PyObject seq);
648
649	PyTypeObject PyTuple_Type = {
650	PyObject_HEAD_INIT(&PyType_Type)
651	0,
652	"tuple",
653	sizeof(PyTupleObject) - sizeof(PyObject *),
654	sizeof(PyObject *),
655	(destructor)tupledealloc, /* tp_dealloc */
656	(printfunc)tupleprint, /* tp_print */
657	0, /* tp_getattr */
658	0, /* tp_setattr */
659	0, /* tp_compare */
660	(reprfunc)tuplerepr, /* tp_repr */
661	0, /* tp_as_number */
662	&tuple_as_sequence, /* tp_as_sequence */
663	&tuple_as_mapping, /* tp_as_mapping */
664	(hashfunc)tuplehash, /* tp_hash */
665	0, /* tp_call */
666	0, /* tp_str */
667	PyObject_GenericGetAttr, /* tp_getattro */
668	0, /* tp_setattro */
669	0, /* tp_as_buffer */
670	Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC \|
671	Py_TPFLAGS_BASETYPE, /* tp_flags */
672	tuple_doc, /* tp_doc */
673	(traverseproc)tupletraverse, /* tp_traverse */
674	0, /* tp_clear */
675	tuplerichcompare, /* tp_richcompare */
676	0, /* tp_weaklistoffset */
677	tuple_iter, /* tp_iter */
678	0, /* tp_iternext */
679	tuple_methods, /* tp_methods */
680	0, /* tp_members */
681	0, /* tp_getset */
682	0, /* tp_base */
683	0, /* tp_dict */
684	0, /* tp_descr_get */
685	0, /* tp_descr_set */
686	0, /* tp_dictoffset */
687	0, /* tp_init */
688	0, /* tp_alloc */
689	tuple_new, /* tp_new */
690	PyObject_GC_Del, /* tp_free */
691	};
692
693	/* The following function breaks the notion that tuples are immutable:
694	it changes the size of a tuple. We get away with this only if there
695	is only one module referencing the object. You can also think of it
696	as creating a new tuple object and destroying the old one, only more
697	efficiently. In any case, don't use this if the tuple may already be
698	known to some other part of the code. */
699
700	int
701	_PyTuple_Resize(PyObject **pv, Py_ssize_t newsize)
702	{
703	register PyTupleObject *v;
704	register PyTupleObject *sv;
705	Py_ssize_t i;
706	Py_ssize_t oldsize;
707
708	v = (PyTupleObject ) pv;
709	if (v == NULL \|\| v->ob_type != &PyTuple_Type \|\|
710	(v->ob_size != 0 && v->ob_refcnt != 1)) {
711	*pv = 0;
712	Py_XDECREF(v);
713	PyErr_BadInternalCall();
714	return -1;
715	}
716	oldsize = v->ob_size;
717	if (oldsize == newsize)
718	return 0;
719
720	if (oldsize == 0) {
721	/* Empty tuples are often shared, so we should never
722	resize them in-place even if we do own the only
723	(current) reference */
724	Py_DECREF(v);
725	*pv = PyTuple_New(newsize);
726	return *pv == NULL ? -1 : 0;
727	}
728
729	/* XXX UNREF/NEWREF interface should be more symmetrical */
730	_Py_DEC_REFTOTAL;
731	_PyObject_GC_UNTRACK(v);
732	_Py_ForgetReference((PyObject *) v);
733	/* DECREF items deleted by shrinkage */
734	for (i = newsize; i < oldsize; i++) {
735	Py_XDECREF(v->ob_item[i]);
736	v->ob_item[i] = NULL;
737	}
738	sv = PyObject_GC_Resize(PyTupleObject, v, newsize);
739	if (sv == NULL) {
740	*pv = NULL;
741	PyObject_GC_Del(v);
742	return -1;
743	}
744	_Py_NewReference((PyObject *) sv);
745	/* Zero out items added by growing */
746	if (newsize > oldsize)
747	memset(&sv->ob_item[oldsize], 0,
748	sizeof(sv->ob_item) (newsize - oldsize));
749	pv = (PyObject ) sv;
750	_PyObject_GC_TRACK(sv);
751	return 0;
752	}
753
754	void
755	PyTuple_Fini(void)
756	{
757	#if MAXSAVESIZE > 0
758	int i;
759
760	Py_XDECREF(free_tuples[0]);
761	free_tuples[0] = NULL;
762
763	for (i = 1; i < MAXSAVESIZE; i++) {
764	PyTupleObject p, q;
765	p = free_tuples[i];
766	free_tuples[i] = NULL;
767	while (p) {
768	q = p;
769	p = (PyTupleObject *)(p->ob_item[0]);
770	PyObject_GC_Del(q);
771	}
772	}
773	#endif
774	}
775
776	/********************* Tuple Iterator ************************/
777
778	typedef struct {
779	PyObject_HEAD
780	long it_index;
781	PyTupleObject it_seq; / Set to NULL when iterator is exhausted */
782	} tupleiterobject;
783
784	static void
785	tupleiter_dealloc(tupleiterobject *it)
786	{
787	_PyObject_GC_UNTRACK(it);
788	Py_XDECREF(it->it_seq);
789	PyObject_GC_Del(it);
790	}
791
792	static int
793	tupleiter_traverse(tupleiterobject it, visitproc visit, void arg)
794	{
795	Py_VISIT(it->it_seq);
796	return 0;
797	}
798
799	static PyObject *
800	tupleiter_next(tupleiterobject *it)
801	{
802	PyTupleObject *seq;
803	PyObject *item;
804
805	assert(it != NULL);
806	seq = it->it_seq;
807	if (seq == NULL)
808	return NULL;
809	assert(PyTuple_Check(seq));
810
811	if (it->it_index < PyTuple_GET_SIZE(seq)) {
812	item = PyTuple_GET_ITEM(seq, it->it_index);
813	++it->it_index;
814	Py_INCREF(item);
815	return item;
816	}
817
818	Py_DECREF(seq);
819	it->it_seq = NULL;
820	return NULL;
821	}
822
823	static PyObject *
824	tupleiter_len(tupleiterobject *it)
825	{
826	Py_ssize_t len = 0;
827	if (it->it_seq)
828	len = PyTuple_GET_SIZE(it->it_seq) - it->it_index;
829	return PyInt_FromSsize_t(len);
830	}
831
832	PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(it)).");
833
834	static PyMethodDef tupleiter_methods[] = {
835	{"__length_hint__", (PyCFunction)tupleiter_len, METH_NOARGS, length_hint_doc},
836	{NULL, NULL} /* sentinel */
837	};
838
839	PyTypeObject PyTupleIter_Type = {
840	PyObject_HEAD_INIT(&PyType_Type)
841	0, /* ob_size */
842	"tupleiterator", /* tp_name */
843	sizeof(tupleiterobject), /* tp_basicsize */
844	0, /* tp_itemsize */
845	/* methods */
846	(destructor)tupleiter_dealloc, /* tp_dealloc */
847	0, /* tp_print */
848	0, /* tp_getattr */
849	0, /* tp_setattr */
850	0, /* tp_compare */
851	0, /* tp_repr */
852	0, /* tp_as_number */
853	0, /* tp_as_sequence */
854	0, /* tp_as_mapping */
855	0, /* tp_hash */
856	0, /* tp_call */
857	0, /* tp_str */
858	PyObject_GenericGetAttr, /* tp_getattro */
859	0, /* tp_setattro */
860	0, /* tp_as_buffer */
861	Py_TPFLAGS_DEFAULT \| Py_TPFLAGS_HAVE_GC,/* tp_flags */
862	0, /* tp_doc */
863	(traverseproc)tupleiter_traverse, /* tp_traverse */
864	0, /* tp_clear */
865	0, /* tp_richcompare */
866	0, /* tp_weaklistoffset */
867	PyObject_SelfIter, /* tp_iter */
868	(iternextfunc)tupleiter_next, /* tp_iternext */
869	tupleiter_methods, /* tp_methods */
870	0,
871	};
872
873	static PyObject *
874	tuple_iter(PyObject *seq)
875	{
876	tupleiterobject *it;
877
878	if (!PyTuple_Check(seq)) {
879	PyErr_BadInternalCall();
880	return NULL;
881	}
882	it = PyObject_GC_New(tupleiterobject, &PyTupleIter_Type);
883	if (it == NULL)
884	return NULL;
885	it->it_index = 0;
886	Py_INCREF(seq);
887	it->it_seq = (PyTupleObject *)seq;
888	_PyObject_GC_TRACK(it);
889	return (PyObject *)it;
890	}

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source: vendor/python/2.5/Objects/tupleobject.c

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