summaryrefslogtreecommitdiffstats
path: root/Objects/structseq.c
blob: a3ff0453d78f55e6b5d4f8e3f8894130824ebec5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
/* Implementation helper: a struct that looks like a tuple.  See timemodule
   and posixmodule for example uses. */

#include "Python.h"
#include "structmember.h"
#include "structseq.h"

static char visible_length_key[] = "n_sequence_fields";
static char real_length_key[] = "n_fields";
static char unnamed_fields_key[] = "n_unnamed_fields";

/* Fields with this name have only a field index, not a field name. 
   They are only allowed for indices < n_visible_fields. */
char *PyStructSequence_UnnamedField = "unnamed field";

#define VISIBLE_SIZE(op) Py_Size(op)
#define VISIBLE_SIZE_TP(tp) PyInt_AsLong( \
                      PyDict_GetItemString((tp)->tp_dict, visible_length_key))

#define REAL_SIZE_TP(tp) PyInt_AsLong( \
                      PyDict_GetItemString((tp)->tp_dict, real_length_key))
#define REAL_SIZE(op) REAL_SIZE_TP(Py_Type(op))

#define UNNAMED_FIELDS_TP(tp) PyInt_AsLong( \
                      PyDict_GetItemString((tp)->tp_dict, unnamed_fields_key))
#define UNNAMED_FIELDS(op) UNNAMED_FIELDS_TP(Py_Type(op))


PyObject *
PyStructSequence_New(PyTypeObject *type)
{
	PyStructSequence *obj;
       
	obj = PyObject_New(PyStructSequence, type);
	Py_Size(obj) = VISIBLE_SIZE_TP(type);

	return (PyObject*) obj;
}

static void
structseq_dealloc(PyStructSequence *obj)
{
	Py_ssize_t i, size;

	size = REAL_SIZE(obj);
	for (i = 0; i < size; ++i) {
		Py_XDECREF(obj->ob_item[i]);
	}
	PyObject_Del(obj);
}

static Py_ssize_t
structseq_length(PyStructSequence *obj)
{
	return VISIBLE_SIZE(obj);
}

static PyObject*
structseq_item(PyStructSequence *obj, Py_ssize_t i)
{
	if (i < 0 || i >= VISIBLE_SIZE(obj)) {
		PyErr_SetString(PyExc_IndexError, "tuple index out of range");
		return NULL;
	}
	Py_INCREF(obj->ob_item[i]);
	return obj->ob_item[i];
}

static PyObject*
structseq_slice(PyStructSequence *obj, Py_ssize_t low, Py_ssize_t high)
{
	PyTupleObject *np;
	Py_ssize_t i;

	if (low < 0)
		low = 0;
	if (high > VISIBLE_SIZE(obj))
		high = VISIBLE_SIZE(obj);
	if (high < low)
		high = low;
	np = (PyTupleObject *)PyTuple_New(high-low);
	if (np == NULL)
		return NULL;
	for(i = low; i < high; ++i) {
		PyObject *v = obj->ob_item[i];
		Py_INCREF(v);
		PyTuple_SET_ITEM(np, i-low, v);
	}
	return (PyObject *) np;
}

static PyObject *
structseq_subscript(PyStructSequence *self, PyObject *item)
{
	if (PyIndex_Check(item)) {
		Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);
		if (i == -1 && PyErr_Occurred())
			return NULL;

		if (i < 0)
			i += VISIBLE_SIZE(self);

		if (i < 0 || i >= VISIBLE_SIZE(self)) {
			PyErr_SetString(PyExc_IndexError,
				"tuple index out of range");
			return NULL;
		}
		Py_INCREF(self->ob_item[i]);
		return self->ob_item[i];
	}
	else if (PySlice_Check(item)) {
		Py_ssize_t start, stop, step, slicelen, cur, i;
		PyObject *result;
		
		if (PySlice_GetIndicesEx((PySliceObject *)item,
					 VISIBLE_SIZE(self), &start, &stop,
					 &step, &slicelen) < 0) {
			return NULL;
		}
		if (slicelen <= 0)
			return PyTuple_New(0);
		result = PyTuple_New(slicelen);
		if (result == NULL)
			return NULL;
		for (cur = start, i = 0; i < slicelen;
		     cur += step, i++) {
			PyObject *v = self->ob_item[cur];
			Py_INCREF(v);
			PyTuple_SET_ITEM(result, i, v);
		}
		return result;
	}
	else {
		PyErr_SetString(PyExc_TypeError,
				"structseq index must be integer");
		return NULL;
	}
}

static PyObject *
structseq_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	PyObject *arg = NULL;
	PyObject *dict = NULL;
	PyObject *ob;
	PyStructSequence *res = NULL;
	Py_ssize_t len, min_len, max_len, i, n_unnamed_fields;
	static char *kwlist[] = {"sequence", "dict", 0};

	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|O:structseq", 
					 kwlist, &arg, &dict))
		return NULL;

	arg = PySequence_Fast(arg, "constructor requires a sequence");

	if (!arg) {				
		return NULL;
	}

	if (dict && !PyDict_Check(dict)) {
		PyErr_Format(PyExc_TypeError, 
			     "%.500s() takes a dict as second arg, if any",
			     type->tp_name);
		Py_DECREF(arg);
		return NULL;
	}

	len = PySequence_Fast_GET_SIZE(arg);
	min_len = VISIBLE_SIZE_TP(type);
	max_len = REAL_SIZE_TP(type);
	n_unnamed_fields = UNNAMED_FIELDS_TP(type);

	if (min_len != max_len) {
		if (len < min_len) {
			PyErr_Format(PyExc_TypeError, 
	       "%.500s() takes an at least %zd-sequence (%zd-sequence given)",
				     type->tp_name, min_len, len);
			Py_DECREF(arg);
			return NULL;
		}

		if (len > max_len) {
			PyErr_Format(PyExc_TypeError, 
	       "%.500s() takes an at most %zd-sequence (%zd-sequence given)",
				     type->tp_name, max_len, len);
			Py_DECREF(arg);
			return NULL;
		}
	} 
	else {
		if (len != min_len) {
			PyErr_Format(PyExc_TypeError, 
	       "%.500s() takes a %zd-sequence (%zd-sequence given)",
				     type->tp_name, min_len, len);
			Py_DECREF(arg);
			return NULL;
		}
	}

	res = (PyStructSequence*) PyStructSequence_New(type);
	if (res == NULL) {
		return NULL;
	}
	for (i = 0; i < len; ++i) {
		PyObject *v = PySequence_Fast_GET_ITEM(arg, i);
		Py_INCREF(v);
		res->ob_item[i] = v;
	}
	for (; i < max_len; ++i) {
		if (dict && (ob = PyDict_GetItemString(
			dict, type->tp_members[i-n_unnamed_fields].name))) {
		}
		else {
			ob = Py_None;
		}
		Py_INCREF(ob);
		res->ob_item[i] = ob;
	}
	
	Py_DECREF(arg);
	return (PyObject*) res;
}

static PyObject *
make_tuple(PyStructSequence *obj)
{
	return structseq_slice(obj, 0, VISIBLE_SIZE(obj));
}

static PyObject *
structseq_repr(PyStructSequence *obj)
{
	PyObject *tup, *str;
	tup = make_tuple(obj);
	str = PyObject_Repr(tup);
	Py_DECREF(tup);
	return str;
}

static PyObject *
structseq_concat(PyStructSequence *obj, PyObject *b)
{
	PyObject *tup, *result;
	tup = make_tuple(obj);
	result = PySequence_Concat(tup, b);
	Py_DECREF(tup);
	return result;
}

static PyObject *
structseq_repeat(PyStructSequence *obj, Py_ssize_t n)
{
	PyObject *tup, *result;
	tup = make_tuple(obj);
	result = PySequence_Repeat(tup, n);
	Py_DECREF(tup);
	return result;
}

static int
structseq_contains(PyStructSequence *obj, PyObject *o)
{
	PyObject *tup;
	int result;
	tup = make_tuple(obj);
	if (!tup)
		return -1;
	result = PySequence_Contains(tup, o);
	Py_DECREF(tup);
	return result;
}

static long
structseq_hash(PyObject *obj)
{
	PyObject *tup;
	long result;
	tup = make_tuple((PyStructSequence*) obj);
	if (!tup)
		return -1;
	result = PyObject_Hash(tup);
	Py_DECREF(tup);
	return result;
}

static PyObject *
structseq_richcompare(PyObject *obj, PyObject *o2, int op)
{
	PyObject *tup, *result;
	tup = make_tuple((PyStructSequence*) obj);
	result = PyObject_RichCompare(tup, o2, op);
	Py_DECREF(tup);
	return result;
}

static PyObject *
structseq_reduce(PyStructSequence* self)
{
	PyObject* tup;
	PyObject* dict;
	PyObject* result;
	Py_ssize_t n_fields, n_visible_fields, n_unnamed_fields;
	int i;
	
	n_fields = REAL_SIZE(self);
	n_visible_fields = VISIBLE_SIZE(self);
	n_unnamed_fields = UNNAMED_FIELDS(self);
	tup = PyTuple_New(n_visible_fields);
	if (!tup) {
		return NULL;
	}

	dict = PyDict_New();
	if (!dict) {
		Py_DECREF(tup);
		return NULL;
	}

	for (i = 0; i < n_visible_fields; i++) {
		Py_INCREF(self->ob_item[i]);
		PyTuple_SET_ITEM(tup, i, self->ob_item[i]);
	}
	
	for (; i < n_fields; i++) {
		char *n = Py_Type(self)->tp_members[i-n_unnamed_fields].name;
		PyDict_SetItemString(dict, n,
				     self->ob_item[i]);
	}

	result = Py_BuildValue("(O(OO))", Py_Type(self), tup, dict);

	Py_DECREF(tup);
	Py_DECREF(dict);

	return result;
}

static PySequenceMethods structseq_as_sequence = {
	(lenfunc)structseq_length,
	(binaryfunc)structseq_concat,           /* sq_concat */
	(ssizeargfunc)structseq_repeat,         /* sq_repeat */
	(ssizeargfunc)structseq_item,		/* sq_item */
	(ssizessizeargfunc)structseq_slice,	/* sq_slice */
	0,					/* sq_ass_item */
	0,					/* sq_ass_slice */
	(objobjproc)structseq_contains,	        /* sq_contains */
};

static PyMappingMethods structseq_as_mapping = {
	(lenfunc)structseq_length,
	(binaryfunc)structseq_subscript,
};

static PyMethodDef structseq_methods[] = {
	{"__reduce__", (PyCFunction)structseq_reduce, 
	 METH_NOARGS, NULL},
	{NULL, NULL}
};

static PyTypeObject _struct_sequence_template = {
	PyVarObject_HEAD_INIT(&PyType_Type, 0)
	NULL,	                     		/* tp_name */
        0,		                        /* tp_basicsize */
	0,	                      		/* tp_itemsize */
	(destructor)structseq_dealloc,	        /* tp_dealloc */
	0,                        	        /* tp_print */
	0,			 		/* tp_getattr */
	0,					/* tp_setattr */
	0,               			/* tp_compare */
	(reprfunc)structseq_repr,             	/* tp_repr */
	0,					/* tp_as_number */
	&structseq_as_sequence,			/* tp_as_sequence */
	&structseq_as_mapping,			/* tp_as_mapping */
	structseq_hash,				/* tp_hash */
	0,              			/* tp_call */
	0,					/* tp_str */
	0,                       		/* tp_getattro */
	0,	                           	/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT,                     /* tp_flags */
	NULL,	 		         	/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	structseq_richcompare,			/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	structseq_methods,      		/* tp_methods */
        NULL,			             	/* tp_members */
	0,			          	/* tp_getset */
	0,					/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,	                                /* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	structseq_new,				/* tp_new */
};

void
PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc)
{
	PyObject *dict;
	PyMemberDef* members;
	int n_members, n_unnamed_members, i, k;

#ifdef Py_TRACE_REFS
	/* if the type object was chained, unchain it first
	   before overwriting its storage */
	if (type->ob_base.ob_base._ob_next) {
		_Py_ForgetReference((PyObject*)type);
	}
#endif

	n_unnamed_members = 0;
	for (i = 0; desc->fields[i].name != NULL; ++i)
		if (desc->fields[i].name == PyStructSequence_UnnamedField)
			n_unnamed_members++;
	n_members = i;

	memcpy(type, &_struct_sequence_template, sizeof(PyTypeObject));
	type->tp_name = desc->name;
	type->tp_doc = desc->doc;
	type->tp_basicsize = sizeof(PyStructSequence)+
		sizeof(PyObject*)*(n_members-1);
	type->tp_itemsize = 0;

	members = PyMem_NEW(PyMemberDef, n_members-n_unnamed_members+1);
	if (members == NULL)
		return;
	
	for (i = k = 0; i < n_members; ++i) {
		if (desc->fields[i].name == PyStructSequence_UnnamedField)
			continue;
		members[k].name = desc->fields[i].name;
		members[k].type = T_OBJECT;
		members[k].offset = offsetof(PyStructSequence, ob_item)
		  + i * sizeof(PyObject*);
		members[k].flags = READONLY;
		members[k].doc = desc->fields[i].doc;
		k++;
	}
	members[k].name = NULL;

	type->tp_members = members;

	if (PyType_Ready(type) < 0)
		return;
	Py_INCREF(type);

	dict = type->tp_dict;
	PyDict_SetItemString(dict, visible_length_key, 
		       PyInt_FromLong((long) desc->n_in_sequence));
	PyDict_SetItemString(dict, real_length_key, 
		       PyInt_FromLong((long) n_members));
	PyDict_SetItemString(dict, unnamed_fields_key, 
		       PyInt_FromLong((long) n_unnamed_members));
}