vigra - vigra/python_utility.hxx Source File

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python_utility.hxx |

1 /************************************************************************/
2 /* */
3 /* Copyright 2009 by Ullrich Koethe and Hans Meine */
4 /* */
5 /* This file is part of the VIGRA computer vision library. */
6 /* The VIGRA Website is */
7 /* http://hci.iwr.uni-heidelberg.de/vigra/ */
8 /* Please direct questions, bug reports, and contributions to */
9 /* ullrich.koethe@iwr.uni-heidelberg.de or */
10 /* vigra@informatik.uni-hamburg.de */
11 /* */
12 /* Permission is hereby granted, free of charge, to any person */
13 /* obtaining a copy of this software and associated documentation */
14 /* files (the "Software"), to deal in the Software without */
15 /* restriction, including without limitation the rights to use, */
16 /* copy, modify, merge, publish, distribute, sublicense, and/or */
17 /* sell copies of the Software, and to permit persons to whom the */
18 /* Software is furnished to do so, subject to the following */
19 /* conditions: */
20 /* */
21 /* The above copyright notice and this permission notice shall be */
22 /* included in all copies or substantial portions of the */
23 /* Software. */
24 /* */
25 /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND */
26 /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES */
27 /* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND */
28 /* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT */
29 /* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, */
30 /* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING */
31 /* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR */
32 /* OTHER DEALINGS IN THE SOFTWARE. */
33 /* */
34 /************************************************************************/
35
36 #ifndef VIGRA_PYTHON_UTILITY_HXX
37 #define VIGRA_PYTHON_UTILITY_HXX
38
39 #include <Python.h>
40 #include <algorithm>
41 #include <string>
42 #include "vigra/error.hxx"
43 #include "vigra/tinyvector.hxx"
44
45 namespace vigra {
46
47 template <class PYOBJECT_PTR>
48 void pythonToCppException(PYOBJECT_PTR obj)
49 {
50 if(obj != 0)
51 return;
52 PyObject * type, * value, * trace;
53 PyErr_Fetch(&type, &value, &trace);
54 if(type == 0)
55 return;
56 std::string message(((PyTypeObject *)type)->tp_name);
57 if(PyString_Check(value))
58 {
59 message += std::string(": ") + PyString_AS_STRING(value);
60 }
61
62 Py_XDECREF(type);
63 Py_XDECREF(value);
64 Py_XDECREF(trace);
65 throw std::runtime_error(message.c_str());
66 }
67
68 /********************************************************/
69 /* */
70 /* python_ptr */
71 /* */
72 /********************************************************/
73
74 class python_ptr
75 {
76 private:
77 PyObject * ptr_;
78
79 public:
80
81 typedef PyObject element_type;
82 typedef PyObject value_type;
83 typedef PyObject * pointer;
84 typedef PyObject & reference;
85
86 enum refcount_policy { increment_count, borrowed_reference = increment_count,
87 keep_count, new_reference = keep_count };
88
89 explicit python_ptr(pointer p = 0, refcount_policy rp = increment_count)
90 : ptr_( p )
91 {
92 if(rp == increment_count)
93 {
94 Py_XINCREF(ptr_);
95 }
96 }
97
98 python_ptr(python_ptr const & p)
99 : ptr_(p.ptr_)
100 {
101 Py_XINCREF(ptr_);
102 }
103
104 python_ptr & operator=(pointer p)
105 {
106 reset(p);
107 return *this;
108 }
109
110 python_ptr & operator=(python_ptr const & r)
111 {
112 reset(r.ptr_);
113 return *this;
114 }
115
116 ~python_ptr()
117 {
118 reset();
119 }
120
121 void reset(pointer p = 0, refcount_policy rp = increment_count)
122 {
123 if(p == ptr_)
124 return;
125 if(rp == increment_count)
126 {
127 Py_XINCREF(p);
128 }
129 Py_XDECREF(ptr_);
130 ptr_ = p;
131 }
132
133 pointer release(bool return_borrowed_reference = false)
134 {
135 pointer p = ptr_;
136 ptr_ = 0;
137 if(return_borrowed_reference)
138 {
139 Py_XDECREF(p);
140 }
141 return p;
142 }
143
144 reference operator* () const
145 {
146 vigra_precondition(ptr_ != 0, "python_ptr::operator*(): Cannot dereference NULL pointer.");
147 return *ptr_;
148 }
149
150 pointer operator-> () const
151 {
152 vigra_precondition(ptr_ != 0, "python_ptr::operator->(): Cannot dereference NULL pointer.");
153 return ptr_;
154 }
155
156 pointer ptr() const
157 {
158 return ptr_;
159 }
160
161 pointer get() const
162 {
163 return ptr_;
164 }
165
166 operator pointer() const
167 {
168 return ptr_;
169 }
170
171 bool operator! () const
172 {
173 return ptr_ == 0;
174 }
175
176 bool unique() const
177 {
178 return ptr_ && ptr_->ob_refcnt == 1;
179 }
180
181 void swap(python_ptr & other)
182 {
183 std::swap(ptr_, other.ptr_);
184 }
185
186 bool operator==(python_ptr const & p) const
187 {
188 return ptr_ == p.ptr_;
189 }
190
191 bool operator==(pointer p) const
192 {
193 return ptr_ == p;
194 }
195
196 bool operator!=(python_ptr const & p) const
197 {
198 return ptr_ != p.ptr_;
199 }
200
201 bool operator!=(pointer p) const
202 {
203 return ptr_ != p;
204 }
205 };
206
207 inline void swap(python_ptr & a, python_ptr & b)
208 {
209 a.swap(b);
210 }
211
212 /****************************************************************/
213
214 inline python_ptr
215 makePythonDictionary(char const * k1 = 0, PyObject * a1 = 0,
216 char const * k2 = 0, PyObject * a2 = 0,
217 char const * k3 = 0, PyObject * a3 = 0)
218 {
219 python_ptr dict(PyDict_New(), python_ptr::keep_count);
220 pythonToCppException(dict);
221 if(k1 && a1)
222 PyDict_SetItemString(dict, k1, a1);
223 if(k2 && a2)
224 PyDict_SetItemString(dict, k2, a2);
225 if(k3 && a3)
226 PyDict_SetItemString(dict, k3, a3);
227 return dict;
228 }
229
230 /****************************************************************/
231
232 inline python_ptr pythonFromData(bool t)
233 {
234 python_ptr res(PyBool_FromLong(t ? 1 : 0), python_ptr::keep_count);
235 pythonToCppException(res);
236 return res;
237 }
238
239 inline python_ptr pythonFromData(std::string const & s)
240 {
241 python_ptr res(PyString_FromString(s.c_str()), python_ptr::keep_count);
242 pythonToCppException(res);
243 return res;
244 }
245
246 inline python_ptr pythonFromData(long long t)
247 {
248 python_ptr res;
249 if(t > (long long)NumericTraits<long>::max() || t < (long long)NumericTraits<long>::min())
250 res = python_ptr(PyLong_FromLongLong(t), python_ptr::keep_count);
251 else
252 res = python_ptr(PyInt_FromLong((long)t), python_ptr::keep_count);
253 pythonToCppException(res);
254 return res;
255 }
256
257 inline python_ptr pythonFromData(unsigned long long t)
258 {
259 python_ptr res;
260 if(t > (unsigned long long)NumericTraits<long>::max())
261 res = python_ptr(PyLong_FromUnsignedLongLong(t), python_ptr::keep_count);
262 else
263 res = python_ptr(PyInt_FromLong((long)t), python_ptr::keep_count);
264 pythonToCppException(res);
265 return res;
266 }
267
268 #define VIGRA_PYTHON_FROM_DATA(type, fct, cast_type) \
269 inline python_ptr pythonFromData(type t) \
270 { \
271 python_ptr res(fct((cast_type)t), python_ptr::keep_count); \
272 pythonToCppException(res); \
273 return res; \
274 }
275
276 VIGRA_PYTHON_FROM_DATA(signed char, PyInt_FromLong, long)
277 VIGRA_PYTHON_FROM_DATA(unsigned char, PyInt_FromLong, long)
278 VIGRA_PYTHON_FROM_DATA(short, PyInt_FromLong, long)
279 VIGRA_PYTHON_FROM_DATA(unsigned short, PyInt_FromLong, long)
280 VIGRA_PYTHON_FROM_DATA(long, PyInt_FromLong, long)
281 VIGRA_PYTHON_FROM_DATA(unsigned long, PyInt_FromSize_t, size_t)
282 VIGRA_PYTHON_FROM_DATA(int, PyInt_FromSsize_t, Py_ssize_t)
283 VIGRA_PYTHON_FROM_DATA(unsigned int, PyInt_FromSize_t, size_t)
284 VIGRA_PYTHON_FROM_DATA(float, PyFloat_FromDouble, double)
285 VIGRA_PYTHON_FROM_DATA(double, PyFloat_FromDouble, double)
286 VIGRA_PYTHON_FROM_DATA(char const *, PyString_FromString, char const *)
287
288 #undef VIGRA_PYTHON_FROM_DATA
289
290 /****************************************************************/
291
292 #define VIGRA_DATA_FROM_PYTHON(type, check, extract) \
293 inline type dataFromPython(PyObject * data, type const & defaultVal) \
294 { \
295 return data && check(data) \
296 ? (type)extract(data) \
297 : defaultVal; \
298 }
299
300 VIGRA_DATA_FROM_PYTHON(signed char, PyInt_Check, PyInt_AsLong)
301 VIGRA_DATA_FROM_PYTHON(unsigned char, PyInt_Check, PyInt_AsLong)
302 VIGRA_DATA_FROM_PYTHON(short, PyInt_Check, PyInt_AsLong)
303 VIGRA_DATA_FROM_PYTHON(unsigned short, PyInt_Check, PyInt_AsLong)
304 VIGRA_DATA_FROM_PYTHON(long, PyInt_Check, PyInt_AsLong)
305 VIGRA_DATA_FROM_PYTHON(unsigned long, PyInt_Check, PyInt_AsUnsignedLongMask)
306 VIGRA_DATA_FROM_PYTHON(int, PyInt_Check, PyInt_AsLong)
307 VIGRA_DATA_FROM_PYTHON(unsigned int, PyInt_Check, PyInt_AsUnsignedLongMask)
308 VIGRA_DATA_FROM_PYTHON(long long, PyInt_Check, PyInt_AsSsize_t)
309 VIGRA_DATA_FROM_PYTHON(unsigned long long, PyInt_Check, PyInt_AsUnsignedLongLongMask)
310 VIGRA_DATA_FROM_PYTHON(float, PyFloat_Check, PyFloat_AsDouble)
311 VIGRA_DATA_FROM_PYTHON(double, PyFloat_Check, PyFloat_AsDouble)
312
313 inline std::string dataFromPython(PyObject * data, const char * defaultVal)
314 {
315 return data && PyString_Check(data)
316 ? std::string(PyString_AsString(data))
317 : std::string(defaultVal);
318 }
319
320 inline std::string dataFromPython(PyObject * data, std::string const & defaultVal)
321 {
322 return data && PyString_Check(data)
323 ? std::string(PyString_AsString(data))
324 : defaultVal;
325 }
326
327 inline python_ptr dataFromPython(PyObject * data, python_ptr defaultVal)
328 {
329 return data
330 ? python_ptr(data)
331 : defaultVal;
332 }
333
334 #undef VIGRA_DATA_FROM_PYTHON
335
336 /****************************************************************/
337
338 template <class T>
339 T pythonGetAttr(PyObject * obj, const char * key, T defaultValue)
340 {
341 if(!obj)
342 return defaultValue;
343
344 python_ptr k(PyString_FromString(key), python_ptr::keep_count);
345 pythonToCppException(k);
346 python_ptr pres(PyObject_GetAttr(obj, k), python_ptr::keep_count);
347 if(!pres)
348 PyErr_Clear();
349 return dataFromPython(pres, defaultValue);
350 }
351
352 inline std::string
353 pythonGetAttr(PyObject * obj, const char * key, const char * defaultValue)
354 {
355 if(!obj)
356 return std::string(defaultValue);
357
358 python_ptr k(PyString_FromString(key), python_ptr::keep_count);
359 pythonToCppException(k);
360 python_ptr pres(PyObject_GetAttr(obj, k), python_ptr::keep_count);
361 if(!pres)
362 PyErr_Clear();
363 return dataFromPython(pres, defaultValue);
364 }
365
366 /****************************************************************/
367
368 template <class T, int N>
369 python_ptr shapeToPythonTuple(TinyVector<T, N> const & shape)
370 {
371 python_ptr tuple(PyTuple_New(N), python_ptr::keep_count);
372 pythonToCppException(tuple);
373 for(unsigned int k=0; k<N; ++k)
374 {
375 PyTuple_SET_ITEM((PyTupleObject *)tuple.get(), k, pythonFromData(shape[k]).release());
376 }
377 return tuple;
378 }
379
380 template <class T>
381 python_ptr shapeToPythonTuple(ArrayVectorView<T> const & shape)
382 {
383 python_ptr tuple(PyTuple_New(shape.size()), python_ptr::keep_count);
384 pythonToCppException(tuple);
385 for(unsigned int k=0; k<shape.size(); ++k)
386 {
387 PyTuple_SET_ITEM((PyTupleObject *)tuple.get(), k, pythonFromData(shape[k]).release());
388 }
389 return tuple;
390 }
391
392 /****************************************************************/
393
394 class PyAllowThreads
395 {
396 PyThreadState * save_;
397
398 // make it non-copyable
399 PyAllowThreads(PyAllowThreads const &);
400 PyAllowThreads & operator=(PyAllowThreads const &);
401
402 public:
403 PyAllowThreads()
404 : save_(PyEval_SaveThread())
405 {}
406
407 ~PyAllowThreads()
408 {
409 PyEval_RestoreThread(save_);
410 }
411 };
412
413 } // namespace vigra
414
415 #endif // VIGRA_PYTHON_UTILITY_HXX

© Ullrich Köthe (ullrich.koethe@iwr.uni-heidelberg.de) Heidelberg Collaboratory for Image Processing, University of Heidelberg, Germany | html generated using doxygen and Python vigra 1.10.0 (Mon Nov 18 2013)