Factor out srd_decoder_apiver().
[libsigrokdecode.git] / decoder.c
1 /*
2  * This file is part of the libsigrokdecode project.
3  *
4  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
5  * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
6  *
7  * This program is free software: you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation, either version 3 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
19  */
20
21 #include <config.h>
22 #include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
23 #include "libsigrokdecode.h"
24 #include <glib.h>
25
26 /**
27  * @file
28  *
29  * Listing, loading, unloading, and handling protocol decoders.
30  */
31
32 /**
33  * @defgroup grp_decoder Protocol decoders
34  *
35  * Handling protocol decoders.
36  *
37  * @{
38  */
39
40 /** @cond PRIVATE */
41
42 /* The list of loaded protocol decoders. */
43 static GSList *pd_list = NULL;
44
45 /* srd.c */
46 extern SRD_PRIV GSList *searchpaths;
47
48 /* session.c */
49 extern SRD_PRIV GSList *sessions;
50 extern SRD_PRIV int max_session_id;
51
52 /* module_sigrokdecode.c */
53 extern SRD_PRIV PyObject *mod_sigrokdecode;
54
55 /** @endcond */
56
57 static gboolean srd_check_init(void)
58 {
59         if (max_session_id < 0) {
60                 srd_err("Library is not initialized.");
61                 return FALSE;
62         } else
63                 return TRUE;
64 }
65
66 /**
67  * Returns the list of loaded protocol decoders.
68  *
69  * This is a GSList of pointers to struct srd_decoder items.
70  *
71  * @return List of decoders, NULL if none are supported or loaded.
72  *
73  * @since 0.2.0
74  */
75 SRD_API const GSList *srd_decoder_list(void)
76 {
77         return pd_list;
78 }
79
80 /**
81  * Get the decoder with the specified ID.
82  *
83  * @param id The ID string of the decoder to return.
84  *
85  * @return The decoder with the specified ID, or NULL if not found.
86  *
87  * @since 0.1.0
88  */
89 SRD_API struct srd_decoder *srd_decoder_get_by_id(const char *id)
90 {
91         GSList *l;
92         struct srd_decoder *dec;
93
94         for (l = pd_list; l; l = l->next) {
95                 dec = l->data;
96                 if (!strcmp(dec->id, id))
97                         return dec;
98         }
99
100         return NULL;
101 }
102
103 static void channel_free(void *data)
104 {
105         struct srd_channel *ch = data;
106
107         if (!ch)
108                 return;
109
110         g_free(ch->desc);
111         g_free(ch->name);
112         g_free(ch->id);
113         g_free(ch);
114 }
115
116 static void variant_free(void *data)
117 {
118         GVariant *var = data;
119
120         if (!var)
121                 return;
122
123         g_variant_unref(var);
124 }
125
126 static void annotation_row_free(void *data)
127 {
128         struct srd_decoder_annotation_row *row = data;
129
130         if (!row)
131                 return;
132
133         g_slist_free(row->ann_classes);
134         g_free(row->desc);
135         g_free(row->id);
136         g_free(row);
137 }
138
139 static void decoder_option_free(void *data)
140 {
141         struct srd_decoder_option *opt = data;
142
143         if (!opt)
144                 return;
145
146         g_slist_free_full(opt->values, &variant_free);
147         variant_free(opt->def);
148         g_free(opt->desc);
149         g_free(opt->id);
150         g_free(opt);
151 }
152
153 static void decoder_free(struct srd_decoder *dec)
154 {
155         if (!dec)
156                 return;
157
158         Py_XDECREF(dec->py_dec);
159         Py_XDECREF(dec->py_mod);
160
161         g_slist_free_full(dec->options, &decoder_option_free);
162         g_slist_free_full(dec->binary, (GDestroyNotify)&g_strfreev);
163         g_slist_free_full(dec->annotation_rows, &annotation_row_free);
164         g_slist_free_full(dec->annotations, (GDestroyNotify)&g_strfreev);
165         g_slist_free_full(dec->opt_channels, &channel_free);
166         g_slist_free_full(dec->channels, &channel_free);
167
168         g_free(dec->license);
169         g_free(dec->desc);
170         g_free(dec->longname);
171         g_free(dec->name);
172         g_free(dec->id);
173
174         g_free(dec);
175 }
176
177 static int get_channels(const struct srd_decoder *d, const char *attr,
178                 GSList **out_pdchl, int offset)
179 {
180         PyObject *py_channellist, *py_entry;
181         struct srd_channel *pdch;
182         GSList *pdchl;
183         ssize_t i;
184
185         if (!PyObject_HasAttrString(d->py_dec, attr))
186                 /* No channels of this type specified. */
187                 return SRD_OK;
188
189         pdchl = NULL;
190
191         py_channellist = PyObject_GetAttrString(d->py_dec, attr);
192         if (!py_channellist)
193                 goto except_out;
194
195         if (!PyTuple_Check(py_channellist)) {
196                 srd_err("Protocol decoder %s %s attribute is not a tuple.",
197                         d->name, attr);
198                 goto err_out;
199         }
200
201         for (i = PyTuple_Size(py_channellist) - 1; i >= 0; i--) {
202                 py_entry = PyTuple_GetItem(py_channellist, i);
203                 if (!py_entry)
204                         goto except_out;
205
206                 if (!PyDict_Check(py_entry)) {
207                         srd_err("Protocol decoder %s %s attribute is not "
208                                 "a list of dict elements.", d->name, attr);
209                         goto err_out;
210                 }
211                 pdch = g_malloc0(sizeof(struct srd_channel));
212                 /* Add to list right away so it doesn't get lost. */
213                 pdchl = g_slist_prepend(pdchl, pdch);
214
215                 if (py_dictitem_as_str(py_entry, "id", &pdch->id) != SRD_OK)
216                         goto err_out;
217                 if (py_dictitem_as_str(py_entry, "name", &pdch->name) != SRD_OK)
218                         goto err_out;
219                 if (py_dictitem_as_str(py_entry, "desc", &pdch->desc) != SRD_OK)
220                         goto err_out;
221
222                 pdch->order = offset + i;
223         }
224
225         Py_DECREF(py_channellist);
226         *out_pdchl = pdchl;
227
228         return SRD_OK;
229
230 except_out:
231         srd_exception_catch("Failed to get %s list of %s decoder",
232                         attr, d->name);
233 err_out:
234         g_slist_free_full(pdchl, &channel_free);
235         Py_XDECREF(py_channellist);
236
237         return SRD_ERR_PYTHON;
238 }
239
240 static int get_options(struct srd_decoder *d)
241 {
242         PyObject *py_opts, *py_opt, *py_str, *py_values, *py_default, *py_item;
243         GSList *options;
244         struct srd_decoder_option *o;
245         GVariant *gvar;
246         ssize_t opt, i;
247
248         if (!PyObject_HasAttrString(d->py_dec, "options"))
249                 /* No options, that's fine. */
250                 return SRD_OK;
251
252         options = NULL;
253
254         /* If present, options must be a tuple. */
255         py_opts = PyObject_GetAttrString(d->py_dec, "options");
256         if (!py_opts)
257                 goto except_out;
258
259         if (!PyTuple_Check(py_opts)) {
260                 srd_err("Protocol decoder %s: options attribute is not "
261                                 "a tuple.", d->id);
262                 goto err_out;
263         }
264
265         for (opt = PyTuple_Size(py_opts) - 1; opt >= 0; opt--) {
266                 py_opt = PyTuple_GetItem(py_opts, opt);
267                 if (!py_opt)
268                         goto except_out;
269
270                 if (!PyDict_Check(py_opt)) {
271                         srd_err("Protocol decoder %s options: each option "
272                                         "must consist of a dictionary.", d->name);
273                         goto err_out;
274                 }
275
276                 o = g_malloc0(sizeof(struct srd_decoder_option));
277                 /* Add to list right away so it doesn't get lost. */
278                 options = g_slist_prepend(options, o);
279
280                 py_str = PyDict_GetItemString(py_opt, "id");
281                 if (!py_str) {
282                         srd_err("Protocol decoder %s option %zd has no id.",
283                                 d->name, opt);
284                         goto err_out;
285                 }
286                 if (py_str_as_str(py_str, &o->id) != SRD_OK)
287                         goto err_out;
288
289                 py_str = PyDict_GetItemString(py_opt, "desc");
290                 if (py_str) {
291                         if (py_str_as_str(py_str, &o->desc) != SRD_OK)
292                                 goto err_out;
293                 }
294
295                 py_default = PyDict_GetItemString(py_opt, "default");
296                 if (py_default) {
297                         gvar = py_obj_to_variant(py_default);
298                         if (!gvar) {
299                                 srd_err("Protocol decoder %s option 'default' has "
300                                         "invalid default value.", d->name);
301                                 goto err_out;
302                         }
303                         o->def = g_variant_ref_sink(gvar);
304                 }
305
306                 py_values = PyDict_GetItemString(py_opt, "values");
307                 if (py_values) {
308                         /* A default is required if a list of values is
309                          * given, since it's used to verify their type. */
310                         if (!o->def) {
311                                 srd_err("No default for option '%s'.", o->id);
312                                 goto err_out;
313                         }
314                         if (!PyTuple_Check(py_values)) {
315                                 srd_err("Option '%s' values should be a tuple.", o->id);
316                                 goto err_out;
317                         }
318
319                         for (i = PyTuple_Size(py_values) - 1; i >= 0; i--) {
320                                 py_item = PyTuple_GetItem(py_values, i);
321                                 if (!py_item)
322                                         goto except_out;
323
324                                 if (Py_TYPE(py_default) != Py_TYPE(py_item)) {
325                                         srd_err("All values for option '%s' must be "
326                                                 "of the same type as the default.",
327                                                 o->id);
328                                         goto err_out;
329                                 }
330                                 gvar = py_obj_to_variant(py_item);
331                                 if (!gvar) {
332                                         srd_err("Protocol decoder %s option 'values' "
333                                                 "contains invalid value.", d->name);
334                                         goto err_out;
335                                 }
336                                 o->values = g_slist_prepend(o->values,
337                                                 g_variant_ref_sink(gvar));
338                         }
339                 }
340         }
341         d->options = options;
342         Py_DECREF(py_opts);
343
344         return SRD_OK;
345
346 except_out:
347         srd_exception_catch("Failed to get %s decoder options", d->name);
348 err_out:
349         g_slist_free_full(options, &decoder_option_free);
350         Py_XDECREF(py_opts);
351
352         return SRD_ERR_PYTHON;
353 }
354
355 /* Convert annotation class attribute to GSList of char **.
356  */
357 static int get_annotations(struct srd_decoder *dec)
358 {
359         PyObject *py_annlist, *py_ann;
360         GSList *annotations;
361         char **annpair;
362         ssize_t i;
363
364         if (!PyObject_HasAttrString(dec->py_dec, "annotations"))
365                 return SRD_OK;
366
367         annotations = NULL;
368
369         py_annlist = PyObject_GetAttrString(dec->py_dec, "annotations");
370         if (!py_annlist)
371                 goto except_out;
372
373         if (!PyTuple_Check(py_annlist)) {
374                 srd_err("Protocol decoder %s annotations should "
375                         "be a tuple.", dec->name);
376                 goto err_out;
377         }
378
379         for (i = PyTuple_Size(py_annlist) - 1; i >= 0; i--) {
380                 py_ann = PyTuple_GetItem(py_annlist, i);
381                 if (!py_ann)
382                         goto except_out;
383
384                 if (!PyTuple_Check(py_ann) || PyTuple_Size(py_ann) != 2) {
385                         srd_err("Protocol decoder %s annotation %zd should "
386                                 "be a tuple with two elements.",
387                                 dec->name, i + 1);
388                         goto err_out;
389                 }
390                 if (py_strseq_to_char(py_ann, &annpair) != SRD_OK)
391                         goto err_out;
392
393                 annotations = g_slist_prepend(annotations, annpair);
394         }
395         dec->annotations = annotations;
396         Py_DECREF(py_annlist);
397
398         return SRD_OK;
399
400 except_out:
401         srd_exception_catch("Failed to get %s decoder annotations", dec->name);
402 err_out:
403         g_slist_free_full(annotations, (GDestroyNotify)&g_strfreev);
404         Py_XDECREF(py_annlist);
405
406         return SRD_ERR_PYTHON;
407 }
408
409 /* Convert annotation_rows to GSList of 'struct srd_decoder_annotation_row'.
410  */
411 static int get_annotation_rows(struct srd_decoder *dec)
412 {
413         PyObject *py_ann_rows, *py_ann_row, *py_ann_classes, *py_item;
414         GSList *annotation_rows;
415         struct srd_decoder_annotation_row *ann_row;
416         ssize_t i, k;
417         size_t class_idx;
418
419         if (!PyObject_HasAttrString(dec->py_dec, "annotation_rows"))
420                 return SRD_OK;
421
422         annotation_rows = NULL;
423
424         py_ann_rows = PyObject_GetAttrString(dec->py_dec, "annotation_rows");
425         if (!py_ann_rows)
426                 goto except_out;
427
428         if (!PyTuple_Check(py_ann_rows)) {
429                 srd_err("Protocol decoder %s annotation_rows "
430                         "must be a tuple.", dec->name);
431                 goto err_out;
432         }
433
434         for (i = PyTuple_Size(py_ann_rows) - 1; i >= 0; i--) {
435                 py_ann_row = PyTuple_GetItem(py_ann_rows, i);
436                 if (!py_ann_row)
437                         goto except_out;
438
439                 if (!PyTuple_Check(py_ann_row) || PyTuple_Size(py_ann_row) != 3) {
440                         srd_err("Protocol decoder %s annotation_rows "
441                                 "must contain only tuples of 3 elements.",
442                                 dec->name);
443                         goto err_out;
444                 }
445                 ann_row = g_malloc0(sizeof(struct srd_decoder_annotation_row));
446                 /* Add to list right away so it doesn't get lost. */
447                 annotation_rows = g_slist_prepend(annotation_rows, ann_row);
448
449                 py_item = PyTuple_GetItem(py_ann_row, 0);
450                 if (!py_item)
451                         goto except_out;
452                 if (py_str_as_str(py_item, &ann_row->id) != SRD_OK)
453                         goto err_out;
454
455                 py_item = PyTuple_GetItem(py_ann_row, 1);
456                 if (!py_item)
457                         goto except_out;
458                 if (py_str_as_str(py_item, &ann_row->desc) != SRD_OK)
459                         goto err_out;
460
461                 py_ann_classes = PyTuple_GetItem(py_ann_row, 2);
462                 if (!py_ann_classes)
463                         goto except_out;
464
465                 if (!PyTuple_Check(py_ann_classes)) {
466                         srd_err("Protocol decoder %s annotation_rows tuples "
467                                 "must have a tuple of numbers as 3rd element.",
468                                 dec->name);
469                         goto err_out;
470                 }
471
472                 for (k = PyTuple_Size(py_ann_classes) - 1; k >= 0; k--) {
473                         py_item = PyTuple_GetItem(py_ann_classes, k);
474                         if (!py_item)
475                                 goto except_out;
476
477                         if (!PyLong_Check(py_item)) {
478                                 srd_err("Protocol decoder %s annotation row "
479                                         "class tuple must only contain numbers.",
480                                         dec->name);
481                                 goto err_out;
482                         }
483                         class_idx = PyLong_AsSize_t(py_item);
484                         if (PyErr_Occurred())
485                                 goto except_out;
486
487                         ann_row->ann_classes = g_slist_prepend(ann_row->ann_classes,
488                                         GSIZE_TO_POINTER(class_idx));
489                 }
490         }
491         dec->annotation_rows = annotation_rows;
492         Py_DECREF(py_ann_rows);
493
494         return SRD_OK;
495
496 except_out:
497         srd_exception_catch("Failed to get %s decoder annotation rows",
498                         dec->name);
499 err_out:
500         g_slist_free_full(annotation_rows, &annotation_row_free);
501         Py_XDECREF(py_ann_rows);
502
503         return SRD_ERR_PYTHON;
504 }
505
506 /* Convert binary classes to GSList of char **.
507  */
508 static int get_binary_classes(struct srd_decoder *dec)
509 {
510         PyObject *py_bin_classes, *py_bin_class;
511         GSList *bin_classes;
512         char **bin;
513         ssize_t i;
514
515         if (!PyObject_HasAttrString(dec->py_dec, "binary"))
516                 return SRD_OK;
517
518         bin_classes = NULL;
519
520         py_bin_classes = PyObject_GetAttrString(dec->py_dec, "binary");
521         if (!py_bin_classes)
522                 goto except_out;
523
524         if (!PyTuple_Check(py_bin_classes)) {
525                 srd_err("Protocol decoder %s binary classes should "
526                         "be a tuple.", dec->name);
527                 goto err_out;
528         }
529
530         for (i = PyTuple_Size(py_bin_classes) - 1; i >= 0; i--) {
531                 py_bin_class = PyTuple_GetItem(py_bin_classes, i);
532                 if (!py_bin_class)
533                         goto except_out;
534
535                 if (!PyTuple_Check(py_bin_class)
536                                 || PyTuple_Size(py_bin_class) != 2) {
537                         srd_err("Protocol decoder %s binary classes should "
538                                 "consist only of tuples of 2 elements.",
539                                 dec->name);
540                         goto err_out;
541                 }
542                 if (py_strseq_to_char(py_bin_class, &bin) != SRD_OK)
543                         goto err_out;
544
545                 bin_classes = g_slist_prepend(bin_classes, bin);
546         }
547         dec->binary = bin_classes;
548         Py_DECREF(py_bin_classes);
549
550         return SRD_OK;
551
552 except_out:
553         srd_exception_catch("Failed to get %s decoder binary classes",
554                         dec->name);
555 err_out:
556         g_slist_free_full(bin_classes, (GDestroyNotify)&g_strfreev);
557         Py_XDECREF(py_bin_classes);
558
559         return SRD_ERR_PYTHON;
560 }
561
562 /* Check whether the Decoder class defines the named method.
563  */
564 static int check_method(PyObject *py_dec, const char *mod_name,
565                 const char *method_name)
566 {
567         PyObject *py_method;
568         int is_callable;
569
570         py_method = PyObject_GetAttrString(py_dec, method_name);
571         if (!py_method) {
572                 srd_exception_catch("Protocol decoder %s Decoder class "
573                                 "has no %s() method", mod_name, method_name);
574                 return SRD_ERR_PYTHON;
575         }
576
577         is_callable = PyCallable_Check(py_method);
578         Py_DECREF(py_method);
579
580         if (!is_callable) {
581                 srd_err("Protocol decoder %s Decoder class attribute '%s' "
582                         "is not a method.", mod_name, method_name);
583                 return SRD_ERR_PYTHON;
584         }
585
586         return SRD_OK;
587 }
588
589 /**
590  * Get the API version of the specified decoder.
591  *
592  * @param d The decoder to use. Must not be NULL.
593  *
594  * @return The API version of the decoder, or 0 upon errors.
595  */
596 SRD_PRIV long srd_decoder_apiver(const struct srd_decoder *d)
597 {
598         PyObject *py_apiver;
599         long apiver;
600
601         if (!d)
602                 return 0;
603
604         py_apiver = PyObject_GetAttrString(d->py_dec, "api_version");
605         apiver = (py_apiver && PyLong_Check(py_apiver))
606                         ? PyLong_AsLong(py_apiver) : 0;
607         Py_XDECREF(py_apiver);
608
609         return apiver;
610 }
611
612 /**
613  * Load a protocol decoder module into the embedded Python interpreter.
614  *
615  * @param module_name The module name to be loaded.
616  *
617  * @return SRD_OK upon success, a (negative) error code otherwise.
618  *
619  * @since 0.1.0
620  */
621 SRD_API int srd_decoder_load(const char *module_name)
622 {
623         PyObject *py_basedec;
624         struct srd_decoder *d;
625         long apiver;
626         int is_subclass;
627
628         if (!srd_check_init())
629                 return SRD_ERR;
630
631         if (!module_name)
632                 return SRD_ERR_ARG;
633
634         if (PyDict_GetItemString(PyImport_GetModuleDict(), module_name)) {
635                 /* Module was already imported. */
636                 return SRD_OK;
637         }
638
639         srd_dbg("Loading protocol decoder '%s'.", module_name);
640
641         d = g_malloc0(sizeof(struct srd_decoder));
642
643         d->py_mod = py_import_by_name(module_name);
644         if (!d->py_mod)
645                 goto except_out;
646
647         if (!mod_sigrokdecode) {
648                 srd_err("sigrokdecode module not loaded.");
649                 goto err_out;
650         }
651
652         /* Get the 'Decoder' class as Python object. */
653         d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder");
654         if (!d->py_dec)
655                 goto except_out;
656
657         py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder");
658         if (!py_basedec)
659                 goto except_out;
660
661         is_subclass = PyObject_IsSubclass(d->py_dec, py_basedec);
662         Py_DECREF(py_basedec);
663
664         if (!is_subclass) {
665                 srd_err("Decoder class in protocol decoder module %s is not "
666                         "a subclass of sigrokdecode.Decoder.", module_name);
667                 goto err_out;
668         }
669
670         /*
671          * Check that this decoder has the correct PD API version.
672          * PDs of different API versions are incompatible and cannot work.
673          */
674         apiver = srd_decoder_apiver(d);
675         if (apiver != 2) {
676                 srd_exception_catch("Only PDs of API version 2 are supported");
677                 goto err_out;
678         }
679
680         /* Check Decoder class for required methods.
681          */
682         if (check_method(d->py_dec, module_name, "start") != SRD_OK)
683                 goto err_out;
684
685         if (check_method(d->py_dec, module_name, "decode") != SRD_OK)
686                 goto err_out;
687
688         /* Store required fields in newly allocated strings. */
689         if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
690                 goto err_out;
691
692         if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK)
693                 goto err_out;
694
695         if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK)
696                 goto err_out;
697
698         if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK)
699                 goto err_out;
700
701         if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK)
702                 goto err_out;
703
704         /* All options and their default values. */
705         if (get_options(d) != SRD_OK)
706                 goto err_out;
707
708         /* Check and import required channels. */
709         if (get_channels(d, "channels", &d->channels, 0) != SRD_OK)
710                 goto err_out;
711
712         /* Check and import optional channels. */
713         if (get_channels(d, "optional_channels", &d->opt_channels,
714                                 g_slist_length(d->channels)) != SRD_OK)
715                 goto err_out;
716
717         if (get_annotations(d) != SRD_OK)
718                 goto err_out;
719
720         if (get_annotation_rows(d) != SRD_OK)
721                 goto err_out;
722
723         if (get_binary_classes(d) != SRD_OK)
724                 goto err_out;
725
726         /* Append it to the list of loaded decoders. */
727         pd_list = g_slist_append(pd_list, d);
728
729         return SRD_OK;
730
731 except_out:
732         srd_exception_catch("Failed to load decoder %s", module_name);
733 err_out:
734         decoder_free(d);
735
736         return SRD_ERR_PYTHON;
737 }
738
739 /**
740  * Return a protocol decoder's docstring.
741  *
742  * @param dec The loaded protocol decoder.
743  *
744  * @return A newly allocated buffer containing the protocol decoder's
745  *         documentation. The caller is responsible for free'ing the buffer.
746  *
747  * @since 0.1.0
748  */
749 SRD_API char *srd_decoder_doc_get(const struct srd_decoder *dec)
750 {
751         PyObject *py_str;
752         char *doc;
753
754         if (!srd_check_init())
755                 return NULL;
756
757         if (!dec)
758                 return NULL;
759
760         if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
761                 return NULL;
762
763         if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
764                 srd_exception_catch("Failed to get docstring");
765                 return NULL;
766         }
767
768         doc = NULL;
769         if (py_str != Py_None)
770                 py_str_as_str(py_str, &doc);
771         Py_DECREF(py_str);
772
773         return doc;
774 }
775
776 /**
777  * Unload the specified protocol decoder.
778  *
779  * @param dec The struct srd_decoder to be unloaded.
780  *
781  * @return SRD_OK upon success, a (negative) error code otherwise.
782  *
783  * @since 0.1.0
784  */
785 SRD_API int srd_decoder_unload(struct srd_decoder *dec)
786 {
787         struct srd_session *sess;
788         GSList *l;
789
790         if (!srd_check_init())
791                 return SRD_ERR;
792
793         if (!dec)
794                 return SRD_ERR_ARG;
795
796         srd_dbg("Unloading protocol decoder '%s'.", dec->name);
797
798         /*
799          * Since any instances of this decoder need to be released as well,
800          * but they could be anywhere in the stack, just free the entire
801          * stack. A frontend reloading a decoder thus has to restart all
802          * instances, and rebuild the stack.
803          */
804         for (l = sessions; l; l = l->next) {
805                 sess = l->data;
806                 srd_inst_free_all(sess, NULL);
807         }
808
809         /* Remove the PD from the list of loaded decoders. */
810         pd_list = g_slist_remove(pd_list, dec);
811
812         decoder_free(dec);
813
814         return SRD_OK;
815 }
816
817 static void srd_decoder_load_all_zip_path(char *path)
818 {
819         PyObject *zipimport_mod, *zipimporter_class, *zipimporter;
820         PyObject *prefix_obj, *files, *key, *value, *set, *modname;
821         Py_ssize_t pos = 0;
822         char *prefix;
823         size_t prefix_len;
824
825         set = files = prefix_obj = zipimporter = zipimporter_class = NULL;
826
827         zipimport_mod = py_import_by_name("zipimport");
828         if (zipimport_mod == NULL)
829                 goto err_out;
830
831         zipimporter_class = PyObject_GetAttrString(zipimport_mod, "zipimporter");
832         if (zipimporter_class == NULL)
833                 goto err_out;
834
835         zipimporter = PyObject_CallFunction(zipimporter_class, "s", path);
836         if (zipimporter == NULL)
837                 goto err_out;
838
839         prefix_obj = PyObject_GetAttrString(zipimporter, "prefix");
840         if (prefix_obj == NULL)
841                 goto err_out;
842
843         files = PyObject_GetAttrString(zipimporter, "_files");
844         if (files == NULL || !PyDict_Check(files))
845                 goto err_out;
846
847         set = PySet_New(NULL);
848         if (set == NULL)
849                 goto err_out;
850
851         if (py_str_as_str(prefix_obj, &prefix) != SRD_OK)
852                 goto err_out;
853
854         prefix_len = strlen(prefix);
855
856         while (PyDict_Next(files, &pos, &key, &value)) {
857                 char *path, *slash;
858                 if (py_str_as_str(key, &path) == SRD_OK) {
859                         if (strlen(path) > prefix_len
860                                         && memcmp(path, prefix, prefix_len) == 0
861                                         && (slash = strchr(path + prefix_len, '/'))) {
862
863                                 modname = PyUnicode_FromStringAndSize(path + prefix_len,
864                                                         slash - (path + prefix_len));
865                                 if (modname == NULL) {
866                                         PyErr_Clear();
867                                 } else {
868                                         PySet_Add(set, modname);
869                                         Py_DECREF(modname);
870                                 }
871                         }
872                         g_free(path);
873                 }
874         }
875         g_free(prefix);
876
877         while ((modname = PySet_Pop(set))) {
878                 char *modname_str;
879                 if (py_str_as_str(modname, &modname_str) == SRD_OK) {
880                         /* The directory name is the module name (e.g. "i2c"). */
881                         srd_decoder_load(modname_str);
882                         g_free(modname_str);
883                 }
884                 Py_DECREF(modname);
885         }
886
887 err_out:
888         Py_XDECREF(set);
889         Py_XDECREF(files);
890         Py_XDECREF(prefix_obj);
891         Py_XDECREF(zipimporter);
892         Py_XDECREF(zipimporter_class);
893         Py_XDECREF(zipimport_mod);
894         PyErr_Clear();
895 }
896
897 static void srd_decoder_load_all_path(char *path)
898 {
899         GDir *dir;
900         const gchar *direntry;
901
902         if (!(dir = g_dir_open(path, 0, NULL))) {
903                 /* Not really fatal */
904                 /* Try zipimport method too */
905                 srd_decoder_load_all_zip_path(path);
906                 return;
907         }
908
909         /* This ignores errors returned by srd_decoder_load(). That
910          * function will have logged the cause, but in any case we
911          * want to continue anyway. */
912         while ((direntry = g_dir_read_name(dir)) != NULL) {
913                 /* The directory name is the module name (e.g. "i2c"). */
914                 srd_decoder_load(direntry);
915         }
916         g_dir_close(dir);
917
918 }
919
920 /**
921  * Load all installed protocol decoders.
922  *
923  * @return SRD_OK upon success, a (negative) error code otherwise.
924  *
925  * @since 0.1.0
926  */
927 SRD_API int srd_decoder_load_all(void)
928 {
929         GSList *l;
930
931         if (!srd_check_init())
932                 return SRD_ERR;
933
934         for (l = searchpaths; l; l = l->next)
935                 srd_decoder_load_all_path(l->data);
936
937         return SRD_OK;
938 }
939
940 /**
941  * Unload all loaded protocol decoders.
942  *
943  * @return SRD_OK upon success, a (negative) error code otherwise.
944  *
945  * @since 0.1.0
946  */
947 SRD_API int srd_decoder_unload_all(void)
948 {
949         GSList *l;
950         struct srd_decoder *dec;
951
952         for (l = pd_list; l; l = l->next) {
953                 dec = l->data;
954                 srd_decoder_unload(dec);
955         }
956         g_slist_free(pd_list);
957         pd_list = NULL;
958
959         return SRD_OK;
960 }
961
962 /** @} */