source: python/trunk/Objects/structseq.c@ 1538

Last change on this file since 1538 was 391, checked in by dmik, 12 years ago

python: Merge vendor 2.7.6 to trunk.
  • Property svn:eol-style set to native
File size: 15.6 KB
Line 
1/* Implementation helper: a struct that looks like a tuple. See timemodule
2 and posixmodule for example uses. */
3
4#include "Python.h"
5#include "structmember.h"
6#include "structseq.h"
7
8static char visible_length_key[] = "n_sequence_fields";
9static char real_length_key[] = "n_fields";
10static char unnamed_fields_key[] = "n_unnamed_fields";
11
12/* Fields with this name have only a field index, not a field name.
13 They are only allowed for indices < n_visible_fields. */
14char *PyStructSequence_UnnamedField = "unnamed field";
15
16#define VISIBLE_SIZE(op) Py_SIZE(op)
17#define VISIBLE_SIZE_TP(tp) PyInt_AsLong( \
18 PyDict_GetItemString((tp)->tp_dict, visible_length_key))
19
20#define REAL_SIZE_TP(tp) PyInt_AsLong( \
21 PyDict_GetItemString((tp)->tp_dict, real_length_key))
22#define REAL_SIZE(op) REAL_SIZE_TP(Py_TYPE(op))
23
24#define UNNAMED_FIELDS_TP(tp) PyInt_AsLong( \
25 PyDict_GetItemString((tp)->tp_dict, unnamed_fields_key))
26#define UNNAMED_FIELDS(op) UNNAMED_FIELDS_TP(Py_TYPE(op))
27
28
29PyObject *
30PyStructSequence_New(PyTypeObject *type)
31{
32 PyStructSequence *obj;
33
34 obj = PyObject_New(PyStructSequence, type);
35 if (obj == NULL)
36 return NULL;
37 Py_SIZE(obj) = VISIBLE_SIZE_TP(type);
38
39 return (PyObject*) obj;
40}
41
42static void
43structseq_dealloc(PyStructSequence *obj)
44{
45 Py_ssize_t i, size;
46
47 size = REAL_SIZE(obj);
48 for (i = 0; i < size; ++i) {
49 Py_XDECREF(obj->ob_item[i]);
50 }
51 PyObject_Del(obj);
52}
53
54static Py_ssize_t
55structseq_length(PyStructSequence *obj)
56{
57 return VISIBLE_SIZE(obj);
58}
59
60static PyObject*
61structseq_item(PyStructSequence *obj, Py_ssize_t i)
62{
63 if (i < 0 || i >= VISIBLE_SIZE(obj)) {
64 PyErr_SetString(PyExc_IndexError, "tuple index out of range");
65 return NULL;
66 }
67 Py_INCREF(obj->ob_item[i]);
68 return obj->ob_item[i];
69}
70
71static PyObject*
72structseq_slice(PyStructSequence *obj, Py_ssize_t low, Py_ssize_t high)
73{
74 PyTupleObject *np;
75 Py_ssize_t i;
76
77 if (low < 0)
78 low = 0;
79 if (high > VISIBLE_SIZE(obj))
80 high = VISIBLE_SIZE(obj);
81 if (high < low)
82 high = low;
83 np = (PyTupleObject *)PyTuple_New(high-low);
84 if (np == NULL)
85 return NULL;
86 for(i = low; i < high; ++i) {
87 PyObject *v = obj->ob_item[i];
88 Py_INCREF(v);
89 PyTuple_SET_ITEM(np, i-low, v);
90 }
91 return (PyObject *) np;
92}
93
94static PyObject *
95structseq_subscript(PyStructSequence *self, PyObject *item)
96{
97 if (PyIndex_Check(item)) {
98 Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);
99 if (i == -1 && PyErr_Occurred())
100 return NULL;
101
102 if (i < 0)
103 i += VISIBLE_SIZE(self);
104
105 if (i < 0 || i >= VISIBLE_SIZE(self)) {
106 PyErr_SetString(PyExc_IndexError,
107 "tuple index out of range");
108 return NULL;
109 }
110 Py_INCREF(self->ob_item[i]);
111 return self->ob_item[i];
112 }
113 else if (PySlice_Check(item)) {
114 Py_ssize_t start, stop, step, slicelen, cur, i;
115 PyObject *result;
116
117 if (PySlice_GetIndicesEx((PySliceObject *)item,
118 VISIBLE_SIZE(self), &start, &stop,
119 &step, &slicelen) < 0) {
120 return NULL;
121 }
122 if (slicelen <= 0)
123 return PyTuple_New(0);
124 result = PyTuple_New(slicelen);
125 if (result == NULL)
126 return NULL;
127 for (cur = start, i = 0; i < slicelen;
128 cur += step, i++) {
129 PyObject *v = self->ob_item[cur];
130 Py_INCREF(v);
131 PyTuple_SET_ITEM(result, i, v);
132 }
133 return result;
134 }
135 else {
136 PyErr_SetString(PyExc_TypeError,
137 "structseq index must be integer");
138 return NULL;
139 }
140}
141
142static PyObject *
143structseq_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
144{
145 PyObject *arg = NULL;
146 PyObject *dict = NULL;
147 PyObject *ob;
148 PyStructSequence *res = NULL;
149 Py_ssize_t len, min_len, max_len, i, n_unnamed_fields;
150 static char *kwlist[] = {"sequence", "dict", 0};
151
152 if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|O:structseq",
153 kwlist, &arg, &dict))
154 return NULL;
155
156 arg = PySequence_Fast(arg, "constructor requires a sequence");
157
158 if (!arg) {
159 return NULL;
160 }
161
162 if (dict && !PyDict_Check(dict)) {
163 PyErr_Format(PyExc_TypeError,
164 "%.500s() takes a dict as second arg, if any",
165 type->tp_name);
166 Py_DECREF(arg);
167 return NULL;
168 }
169
170 len = PySequence_Fast_GET_SIZE(arg);
171 min_len = VISIBLE_SIZE_TP(type);
172 max_len = REAL_SIZE_TP(type);
173 n_unnamed_fields = UNNAMED_FIELDS_TP(type);
174
175 if (min_len != max_len) {
176 if (len < min_len) {
177 PyErr_Format(PyExc_TypeError,
178 "%.500s() takes an at least %zd-sequence (%zd-sequence given)",
179 type->tp_name, min_len, len);
180 Py_DECREF(arg);
181 return NULL;
182 }
183
184 if (len > max_len) {
185 PyErr_Format(PyExc_TypeError,
186 "%.500s() takes an at most %zd-sequence (%zd-sequence given)",
187 type->tp_name, max_len, len);
188 Py_DECREF(arg);
189 return NULL;
190 }
191 }
192 else {
193 if (len != min_len) {
194 PyErr_Format(PyExc_TypeError,
195 "%.500s() takes a %zd-sequence (%zd-sequence given)",
196 type->tp_name, min_len, len);
197 Py_DECREF(arg);
198 return NULL;
199 }
200 }
201
202 res = (PyStructSequence*) PyStructSequence_New(type);
203 if (res == NULL) {
204 Py_DECREF(arg);
205 return NULL;
206 }
207 for (i = 0; i < len; ++i) {
208 PyObject *v = PySequence_Fast_GET_ITEM(arg, i);
209 Py_INCREF(v);
210 res->ob_item[i] = v;
211 }
212 for (; i < max_len; ++i) {
213 if (dict && (ob = PyDict_GetItemString(
214 dict, type->tp_members[i-n_unnamed_fields].name))) {
215 }
216 else {
217 ob = Py_None;
218 }
219 Py_INCREF(ob);
220 res->ob_item[i] = ob;
221 }
222
223 Py_DECREF(arg);
224 return (PyObject*) res;
225}
226
227static PyObject *
228make_tuple(PyStructSequence *obj)
229{
230 return structseq_slice(obj, 0, VISIBLE_SIZE(obj));
231}
232
233static PyObject *
234structseq_repr(PyStructSequence *obj)
235{
236 /* buffer and type size were chosen well considered. */
237#define REPR_BUFFER_SIZE 512
238#define TYPE_MAXSIZE 100
239
240 PyObject *tup;
241 PyTypeObject *typ = Py_TYPE(obj);
242 int i, removelast = 0;
243 Py_ssize_t len;
244 char buf[REPR_BUFFER_SIZE];
245 char *endofbuf, *pbuf = buf;
246
247 /* pointer to end of writeable buffer; safes space for "...)\0" */
248 endofbuf= &buf[REPR_BUFFER_SIZE-5];
249
250 if ((tup = make_tuple(obj)) == NULL) {
251 return NULL;
252 }
253
254 /* "typename(", limited to TYPE_MAXSIZE */
255 len = strlen(typ->tp_name) > TYPE_MAXSIZE ? TYPE_MAXSIZE :
256 strlen(typ->tp_name);
257 strncpy(pbuf, typ->tp_name, len);
258 pbuf += len;
259 *pbuf++ = '(';
260
261 for (i=0; i < VISIBLE_SIZE(obj); i++) {
262 PyObject *val, *repr;
263 char *cname, *crepr;
264
265 cname = typ->tp_members[i].name;
266
267 val = PyTuple_GetItem(tup, i);
268 if (cname == NULL || val == NULL) {
269 return NULL;
270 }
271 repr = PyObject_Repr(val);
272 if (repr == NULL) {
273 Py_DECREF(tup);
274 return NULL;
275 }
276 crepr = PyString_AsString(repr);
277 if (crepr == NULL) {
278 Py_DECREF(tup);
279 Py_DECREF(repr);
280 return NULL;
281 }
282
283 /* + 3: keep space for "=" and ", " */
284 len = strlen(cname) + strlen(crepr) + 3;
285 if ((pbuf+len) <= endofbuf) {
286 strcpy(pbuf, cname);
287 pbuf += strlen(cname);
288 *pbuf++ = '=';
289 strcpy(pbuf, crepr);
290 pbuf += strlen(crepr);
291 *pbuf++ = ',';
292 *pbuf++ = ' ';
293 removelast = 1;
294 Py_DECREF(repr);
295 }
296 else {
297 strcpy(pbuf, "...");
298 pbuf += 3;
299 removelast = 0;
300 Py_DECREF(repr);
301 break;
302 }
303 }
304 Py_DECREF(tup);
305 if (removelast) {
306 /* overwrite last ", " */
307 pbuf-=2;
308 }
309 *pbuf++ = ')';
310 *pbuf = '\0';
311
312 return PyString_FromString(buf);
313}
314
315static PyObject *
316structseq_concat(PyStructSequence *obj, PyObject *b)
317{
318 PyObject *tup, *result;
319 tup = make_tuple(obj);
320 result = PySequence_Concat(tup, b);
321 Py_DECREF(tup);
322 return result;
323}
324
325static PyObject *
326structseq_repeat(PyStructSequence *obj, Py_ssize_t n)
327{
328 PyObject *tup, *result;
329 tup = make_tuple(obj);
330 result = PySequence_Repeat(tup, n);
331 Py_DECREF(tup);
332 return result;
333}
334
335static int
336structseq_contains(PyStructSequence *obj, PyObject *o)
337{
338 PyObject *tup;
339 int result;
340 tup = make_tuple(obj);
341 if (!tup)
342 return -1;
343 result = PySequence_Contains(tup, o);
344 Py_DECREF(tup);
345 return result;
346}
347
348static long
349structseq_hash(PyObject *obj)
350{
351 PyObject *tup;
352 long result;
353 tup = make_tuple((PyStructSequence*) obj);
354 if (!tup)
355 return -1;
356 result = PyObject_Hash(tup);
357 Py_DECREF(tup);
358 return result;
359}
360
361static PyObject *
362structseq_richcompare(PyObject *obj, PyObject *o2, int op)
363{
364 PyObject *tup, *result;
365 tup = make_tuple((PyStructSequence*) obj);
366 result = PyObject_RichCompare(tup, o2, op);
367 Py_DECREF(tup);
368 return result;
369}
370
371static PyObject *
372structseq_reduce(PyStructSequence* self)
373{
374 PyObject* tup;
375 PyObject* dict;
376 PyObject* result;
377 Py_ssize_t n_fields, n_visible_fields, n_unnamed_fields;
378 int i;
379
380 n_fields = REAL_SIZE(self);
381 n_visible_fields = VISIBLE_SIZE(self);
382 n_unnamed_fields = UNNAMED_FIELDS(self);
383 tup = PyTuple_New(n_visible_fields);
384 if (!tup) {
385 return NULL;
386 }
387
388 dict = PyDict_New();
389 if (!dict) {
390 Py_DECREF(tup);
391 return NULL;
392 }
393
394 for (i = 0; i < n_visible_fields; i++) {
395 Py_INCREF(self->ob_item[i]);
396 PyTuple_SET_ITEM(tup, i, self->ob_item[i]);
397 }
398
399 for (; i < n_fields; i++) {
400 char *n = Py_TYPE(self)->tp_members[i-n_unnamed_fields].name;
401 PyDict_SetItemString(dict, n,
402 self->ob_item[i]);
403 }
404
405 result = Py_BuildValue("(O(OO))", Py_TYPE(self), tup, dict);
406
407 Py_DECREF(tup);
408 Py_DECREF(dict);
409
410 return result;
411}
412
413static PySequenceMethods structseq_as_sequence = {
414 (lenfunc)structseq_length,
415 (binaryfunc)structseq_concat, /* sq_concat */
416 (ssizeargfunc)structseq_repeat, /* sq_repeat */
417 (ssizeargfunc)structseq_item, /* sq_item */
418 (ssizessizeargfunc)structseq_slice, /* sq_slice */
419 0, /* sq_ass_item */
420 0, /* sq_ass_slice */
421 (objobjproc)structseq_contains, /* sq_contains */
422};
423
424static PyMappingMethods structseq_as_mapping = {
425 (lenfunc)structseq_length,
426 (binaryfunc)structseq_subscript,
427};
428
429static PyMethodDef structseq_methods[] = {
430 {"__reduce__", (PyCFunction)structseq_reduce,
431 METH_NOARGS, NULL},
432 {NULL, NULL}
433};
434
435static PyTypeObject _struct_sequence_template = {
436 PyVarObject_HEAD_INIT(&PyType_Type, 0)
437 NULL, /* tp_name */
438 0, /* tp_basicsize */
439 0, /* tp_itemsize */
440 (destructor)structseq_dealloc, /* tp_dealloc */
441 0, /* tp_print */
442 0, /* tp_getattr */
443 0, /* tp_setattr */
444 0, /* tp_compare */
445 (reprfunc)structseq_repr, /* tp_repr */
446 0, /* tp_as_number */
447 &structseq_as_sequence, /* tp_as_sequence */
448 &structseq_as_mapping, /* tp_as_mapping */
449 structseq_hash, /* tp_hash */
450 0, /* tp_call */
451 0, /* tp_str */
452 0, /* tp_getattro */
453 0, /* tp_setattro */
454 0, /* tp_as_buffer */
455 Py_TPFLAGS_DEFAULT, /* tp_flags */
456 NULL, /* tp_doc */
457 0, /* tp_traverse */
458 0, /* tp_clear */
459 structseq_richcompare, /* tp_richcompare */
460 0, /* tp_weaklistoffset */
461 0, /* tp_iter */
462 0, /* tp_iternext */
463 structseq_methods, /* tp_methods */
464 NULL, /* tp_members */
465 0, /* tp_getset */
466 0, /* tp_base */
467 0, /* tp_dict */
468 0, /* tp_descr_get */
469 0, /* tp_descr_set */
470 0, /* tp_dictoffset */
471 0, /* tp_init */
472 0, /* tp_alloc */
473 structseq_new, /* tp_new */
474};
475
476void
477PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc)
478{
479 PyObject *dict;
480 PyMemberDef* members;
481 int n_members, n_unnamed_members, i, k;
482
483#ifdef Py_TRACE_REFS
484 /* if the type object was chained, unchain it first
485 before overwriting its storage */
486 if (type->_ob_next) {
487 _Py_ForgetReference((PyObject*)type);
488 }
489#endif
490
491 n_unnamed_members = 0;
492 for (i = 0; desc->fields[i].name != NULL; ++i)
493 if (desc->fields[i].name == PyStructSequence_UnnamedField)
494 n_unnamed_members++;
495 n_members = i;
496
497 memcpy(type, &_struct_sequence_template, sizeof(PyTypeObject));
498 type->tp_name = desc->name;
499 type->tp_doc = desc->doc;
500 type->tp_basicsize = sizeof(PyStructSequence)+
501 sizeof(PyObject*)*(n_members-1);
502 type->tp_itemsize = 0;
503
504 members = PyMem_NEW(PyMemberDef, n_members-n_unnamed_members+1);
505 if (members == NULL)
506 return;
507
508 for (i = k = 0; i < n_members; ++i) {
509 if (desc->fields[i].name == PyStructSequence_UnnamedField)
510 continue;
511 members[k].name = desc->fields[i].name;
512 members[k].type = T_OBJECT;
513 members[k].offset = offsetof(PyStructSequence, ob_item)
514 + i * sizeof(PyObject*);
515 members[k].flags = READONLY;
516 members[k].doc = desc->fields[i].doc;
517 k++;
518 }
519 members[k].name = NULL;
520
521 type->tp_members = members;
522
523 if (PyType_Ready(type) < 0)
524 return;
525 Py_INCREF(type);
526
527 dict = type->tp_dict;
528#define SET_DICT_FROM_INT(key, value) \
529 do { \
530 PyObject *v = PyInt_FromLong((long) value); \
531 if (v != NULL) { \
532 PyDict_SetItemString(dict, key, v); \
533 Py_DECREF(v); \
534 } \
535 } while (0)
536
537 SET_DICT_FROM_INT(visible_length_key, desc->n_in_sequence);
538 SET_DICT_FROM_INT(real_length_key, n_members);
539 SET_DICT_FROM_INT(unnamed_fields_key, n_unnamed_members);
540}
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