File: type_decoder.c

package info (click to toggle)
libsigrokdecode 0.5.2-1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 4,060 kB
  • sloc: python: 22,583; sh: 4,451; ansic: 4,146; makefile: 66
file content (1066 lines) | stat: -rw-r--r-- 28,373 bytes parent folder | download
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
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
/*
 * This file is part of the libsigrokdecode project.
 *
 * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
#include "libsigrokdecode.h"
#include <inttypes.h>

/** @cond PRIVATE */
extern SRD_PRIV GSList *sessions;
/** @endcond */

typedef struct {
        PyObject_HEAD
} srd_Decoder;

/* This is only used for nicer srd_dbg() output. */
static const char *output_type_name(unsigned int idx)
{
	static const char names[][16] = {
		"OUTPUT_ANN",
		"OUTPUT_PYTHON",
		"OUTPUT_BINARY",
		"OUTPUT_META",
		"(invalid)"
	};

	return names[MIN(idx, G_N_ELEMENTS(names) - 1)];
}

static void release_annotation(struct srd_proto_data_annotation *pda)
{
	if (!pda)
		return;
	if (pda->ann_text)
		g_strfreev(pda->ann_text);
}

static int convert_annotation(struct srd_decoder_inst *di, PyObject *obj,
		struct srd_proto_data *pdata)
{
	PyObject *py_tmp;
	struct srd_pd_output *pdo;
	struct srd_proto_data_annotation *pda;
	int ann_class;
	char **ann_text;
	PyGILState_STATE gstate;

	gstate = PyGILState_Ensure();

	/* Should be a list of [annotation class, [string, ...]]. */
	if (!PyList_Check(obj)) {
		srd_err("Protocol decoder %s submitted an annotation that"
			" is not a list", di->decoder->name);
		goto err;
	}

	/* Should have 2 elements. */
	if (PyList_Size(obj) != 2) {
		srd_err("Protocol decoder %s submitted annotation list with "
			"%zd elements instead of 2", di->decoder->name,
			PyList_Size(obj));
		goto err;
	}

	/*
	 * The first element should be an integer matching a previously
	 * registered annotation class.
	 */
	py_tmp = PyList_GetItem(obj, 0);
	if (!PyLong_Check(py_tmp)) {
		srd_err("Protocol decoder %s submitted annotation list, but "
			"first element was not an integer.", di->decoder->name);
		goto err;
	}
	ann_class = PyLong_AsLong(py_tmp);
	if (!(pdo = g_slist_nth_data(di->decoder->annotations, ann_class))) {
		srd_err("Protocol decoder %s submitted data to unregistered "
			"annotation class %d.", di->decoder->name, ann_class);
		goto err;
	}

	/* Second element must be a list. */
	py_tmp = PyList_GetItem(obj, 1);
	if (!PyList_Check(py_tmp)) {
		srd_err("Protocol decoder %s submitted annotation list, but "
			"second element was not a list.", di->decoder->name);
		goto err;
	}
	if (py_strseq_to_char(py_tmp, &ann_text) != SRD_OK) {
		srd_err("Protocol decoder %s submitted annotation list, but "
			"second element was malformed.", di->decoder->name);
		goto err;
	}

	pda = pdata->data;
	pda->ann_class = ann_class;
	pda->ann_text = ann_text;

	PyGILState_Release(gstate);

	return SRD_OK;

err:
	PyGILState_Release(gstate);

	return SRD_ERR_PYTHON;
}

static void release_binary(struct srd_proto_data_binary *pdb)
{
	if (!pdb)
		return;
	g_free((void *)pdb->data);
}

static int convert_binary(struct srd_decoder_inst *di, PyObject *obj,
		struct srd_proto_data *pdata)
{
	struct srd_proto_data_binary *pdb;
	PyObject *py_tmp;
	Py_ssize_t size;
	int bin_class;
	char *class_name, *buf;
	PyGILState_STATE gstate;

	gstate = PyGILState_Ensure();

	/* Should be a list of [binary class, bytes]. */
	if (!PyList_Check(obj)) {
		srd_err("Protocol decoder %s submitted non-list for SRD_OUTPUT_BINARY.",
			di->decoder->name);
		goto err;
	}

	/* Should have 2 elements. */
	if (PyList_Size(obj) != 2) {
		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list "
				"with %zd elements instead of 2", di->decoder->name,
				PyList_Size(obj));
		goto err;
	}

	/* The first element should be an integer. */
	py_tmp = PyList_GetItem(obj, 0);
	if (!PyLong_Check(py_tmp)) {
		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list, "
			"but first element was not an integer.", di->decoder->name);
		goto err;
	}
	bin_class = PyLong_AsLong(py_tmp);
	if (!(class_name = g_slist_nth_data(di->decoder->binary, bin_class))) {
		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY with "
			"unregistered binary class %d.", di->decoder->name, bin_class);
		goto err;
	}

	/* Second element should be bytes. */
	py_tmp = PyList_GetItem(obj, 1);
	if (!PyBytes_Check(py_tmp)) {
		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list, "
			"but second element was not bytes.", di->decoder->name);
		goto err;
	}

	/* Consider an empty set of bytes a bug. */
	if (PyBytes_Size(py_tmp) == 0) {
		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY "
				"with empty data set.", di->decoder->name);
		goto err;
	}

	if (PyBytes_AsStringAndSize(py_tmp, &buf, &size) == -1)
		goto err;

	PyGILState_Release(gstate);

	pdb = pdata->data;
	pdb->bin_class = bin_class;
	pdb->size = size;
	if (!(pdb->data = g_try_malloc(pdb->size)))
		return SRD_ERR_MALLOC;
	memcpy((void *)pdb->data, (const void *)buf, pdb->size);

	return SRD_OK;

err:
	PyGILState_Release(gstate);

	return SRD_ERR_PYTHON;
}

static inline struct srd_decoder_inst *srd_sess_inst_find_by_obj(
	struct srd_session *sess, const GSList *stack, const PyObject *obj)
{
	const GSList *l;
	struct srd_decoder_inst *tmp, *di;

	if (!sess)
		return NULL;

	di = NULL;
	for (l = stack ? stack : sess->di_list; di == NULL && l != NULL; l = l->next) {
		tmp = l->data;
		if (tmp->py_inst == obj)
			di = tmp;
		else if (tmp->next_di)
			di = srd_sess_inst_find_by_obj(sess, tmp->next_di, obj);
	}

	return di;
}

/**
 * Find a decoder instance by its Python object.
 *
 * I.e. find that instance's instantiation of the sigrokdecode.Decoder class.
 * This will recurse to find the instance anywhere in the stack tree of all
 * sessions.
 *
 * @param stack Pointer to a GSList of struct srd_decoder_inst, indicating the
 *              stack to search. To start searching at the bottom level of
 *              decoder instances, pass NULL.
 * @param obj The Python class instantiation.
 *
 * @return Pointer to struct srd_decoder_inst, or NULL if not found.
 *
 * @since 0.1.0
 */
static inline struct srd_decoder_inst *srd_inst_find_by_obj(
		const GSList *stack, const PyObject *obj)
{
	struct srd_decoder_inst *di;
	struct srd_session *sess;
	GSList *l;

	/* Performance shortcut: Handle the most common case first. */
	sess = sessions->data;
	di = sess->di_list->data;
	if (di->py_inst == obj)
		return di; 

	di = NULL;
	for (l = sessions; di == NULL && l != NULL; l = l->next) {
		sess = l->data;
		di = srd_sess_inst_find_by_obj(sess, stack, obj);
	}

	return di;
}

static int convert_meta(struct srd_proto_data *pdata, PyObject *obj)
{
	long long intvalue;
	double dvalue;
	PyGILState_STATE gstate;

	gstate = PyGILState_Ensure();

	if (g_variant_type_equal(pdata->pdo->meta_type, G_VARIANT_TYPE_INT64)) {
		if (!PyLong_Check(obj)) {
			PyErr_Format(PyExc_TypeError, "This output was registered "
					"as 'int', but something else was passed.");
			goto err;
		}
		intvalue = PyLong_AsLongLong(obj);
		if (PyErr_Occurred())
			goto err;
		pdata->data = g_variant_new_int64(intvalue);
	} else if (g_variant_type_equal(pdata->pdo->meta_type, G_VARIANT_TYPE_DOUBLE)) {
		if (!PyFloat_Check(obj)) {
			PyErr_Format(PyExc_TypeError, "This output was registered "
					"as 'float', but something else was passed.");
			goto err;
		}
		dvalue = PyFloat_AsDouble(obj);
		if (PyErr_Occurred())
			goto err;
		pdata->data = g_variant_new_double(dvalue);
	}

	PyGILState_Release(gstate);

	return SRD_OK;

err:
	PyGILState_Release(gstate);

	return SRD_ERR_PYTHON;
}

static void release_meta(GVariant *gvar)
{
	if (!gvar)
		return;
	g_variant_unref(gvar);
}

static PyObject *Decoder_put(PyObject *self, PyObject *args)
{
	GSList *l;
	PyObject *py_data, *py_res;
	struct srd_decoder_inst *di, *next_di;
	struct srd_pd_output *pdo;
	struct srd_proto_data pdata;
	struct srd_proto_data_annotation pda;
	struct srd_proto_data_binary pdb;
	uint64_t start_sample, end_sample;
	int output_id;
	struct srd_pd_callback *cb;
	PyGILState_STATE gstate;

	py_data = NULL;

	gstate = PyGILState_Ensure();

	if (!(di = srd_inst_find_by_obj(NULL, self))) {
		/* Shouldn't happen. */
		srd_dbg("put(): self instance not found.");
		goto err;
	}

	if (!PyArg_ParseTuple(args, "KKiO", &start_sample, &end_sample,
		&output_id, &py_data)) {
		/*
		 * This throws an exception, but by returning NULL here we let
		 * Python raise it. This results in a much better trace in
		 * controller.c on the decode() method call.
		 */
		goto err;
	}

	if (!(l = g_slist_nth(di->pd_output, output_id))) {
		srd_err("Protocol decoder %s submitted invalid output ID %d.",
			di->decoder->name, output_id);
		goto err;
	}
	pdo = l->data;

	srd_spew("Instance %s put %" PRIu64 "-%" PRIu64 " %s on oid %d.",
		 di->inst_id, start_sample, end_sample,
		 output_type_name(pdo->output_type), output_id);

	pdata.start_sample = start_sample;
	pdata.end_sample = end_sample;
	pdata.pdo = pdo;
	pdata.data = NULL;

	switch (pdo->output_type) {
	case SRD_OUTPUT_ANN:
		/* Annotations are only fed to callbacks. */
		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
			pdata.data = &pda;
			/* Convert from PyDict to srd_proto_data_annotation. */
			if (convert_annotation(di, py_data, &pdata) != SRD_OK) {
				/* An error was already logged. */
				break;
			}
			Py_BEGIN_ALLOW_THREADS
			cb->cb(&pdata, cb->cb_data);
			Py_END_ALLOW_THREADS
			release_annotation(pdata.data);
		}
		break;
	case SRD_OUTPUT_PYTHON:
		for (l = di->next_di; l; l = l->next) {
			next_di = l->data;
			srd_spew("Sending %" PRIu64 "-%" PRIu64 " to instance %s",
				 start_sample, end_sample, next_di->inst_id);
			if (!(py_res = PyObject_CallMethod(
				next_di->py_inst, "decode", "KKO", start_sample,
				end_sample, py_data))) {
				srd_exception_catch("Calling %s decode() failed",
							next_di->inst_id);
			}
			Py_XDECREF(py_res);
		}
		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
			/*
			 * Frontends aren't really supposed to get Python
			 * callbacks, but it's useful for testing.
			 */
			pdata.data = py_data;
			cb->cb(&pdata, cb->cb_data);
		}
		break;
	case SRD_OUTPUT_BINARY:
		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
			pdata.data = &pdb;
			/* Convert from PyDict to srd_proto_data_binary. */
			if (convert_binary(di, py_data, &pdata) != SRD_OK) {
				/* An error was already logged. */
				break;
			}
			Py_BEGIN_ALLOW_THREADS
			cb->cb(&pdata, cb->cb_data);
			Py_END_ALLOW_THREADS
			release_binary(pdata.data);
		}
		break;
	case SRD_OUTPUT_META:
		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
			/* Annotations need converting from PyObject. */
			if (convert_meta(&pdata, py_data) != SRD_OK) {
				/* An exception was already set up. */
				break;
			}
			Py_BEGIN_ALLOW_THREADS
			cb->cb(&pdata, cb->cb_data);
			Py_END_ALLOW_THREADS
			release_meta(pdata.data);
		}
		break;
	default:
		srd_err("Protocol decoder %s submitted invalid output type %d.",
			di->decoder->name, pdo->output_type);
		break;
	}

	PyGILState_Release(gstate);

	Py_RETURN_NONE;

err:
	PyGILState_Release(gstate);

	return NULL;
}

static PyObject *Decoder_register(PyObject *self, PyObject *args,
		PyObject *kwargs)
{
	struct srd_decoder_inst *di;
	struct srd_pd_output *pdo;
	PyObject *py_new_output_id;
	PyTypeObject *meta_type_py;
	const GVariantType *meta_type_gv;
	int output_type;
	char *proto_id, *meta_name, *meta_descr;
	char *keywords[] = { "output_type", "proto_id", "meta", NULL };
	PyGILState_STATE gstate;
	gboolean is_meta;
	GSList *l;
	struct srd_pd_output *cmp;

	gstate = PyGILState_Ensure();

	meta_type_py = NULL;
	meta_type_gv = NULL;
	meta_name = meta_descr = NULL;

	if (!(di = srd_inst_find_by_obj(NULL, self))) {
		PyErr_SetString(PyExc_Exception, "decoder instance not found");
		goto err;
	}

	/* Default to instance ID, which defaults to class ID. */
	proto_id = di->inst_id;
	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "i|s(Oss)", keywords,
			&output_type, &proto_id,
			&meta_type_py, &meta_name, &meta_descr)) {
		/* Let Python raise this exception. */
		goto err;
	}

	/* Check if the meta value's type is supported. */
	is_meta = output_type == SRD_OUTPUT_META;
	if (is_meta) {
		if (meta_type_py == &PyLong_Type)
			meta_type_gv = G_VARIANT_TYPE_INT64;
		else if (meta_type_py == &PyFloat_Type)
			meta_type_gv = G_VARIANT_TYPE_DOUBLE;
		else {
			PyErr_Format(PyExc_TypeError, "Unsupported type.");
			goto err;
		}
	}

	pdo = NULL;
	for (l = di->pd_output; l; l = l->next) {
		cmp = l->data;
		if (cmp->output_type != output_type)
			continue;
		if (strcmp(cmp->proto_id, proto_id) != 0)
			continue;
		if (is_meta && cmp->meta_type != meta_type_gv)
			continue;
		if (is_meta && strcmp(cmp->meta_name, meta_name) != 0)
			continue;
		if (is_meta && strcmp(cmp->meta_descr, meta_descr) != 0)
			continue;
		pdo = cmp;
		break;
	}
	if (pdo) {
		py_new_output_id = Py_BuildValue("i", pdo->pdo_id);
		PyGILState_Release(gstate);
		return py_new_output_id;
	}

	srd_dbg("Instance %s creating new output type %d for %s.",
		di->inst_id, output_type, proto_id);

	pdo = g_malloc(sizeof(struct srd_pd_output));

	/* pdo_id is just a simple index, nothing is deleted from this list anyway. */
	pdo->pdo_id = g_slist_length(di->pd_output);
	pdo->output_type = output_type;
	pdo->di = di;
	pdo->proto_id = g_strdup(proto_id);

	if (output_type == SRD_OUTPUT_META) {
		pdo->meta_type = meta_type_gv;
		pdo->meta_name = g_strdup(meta_name);
		pdo->meta_descr = g_strdup(meta_descr);
	}

	di->pd_output = g_slist_append(di->pd_output, pdo);
	py_new_output_id = Py_BuildValue("i", pdo->pdo_id);

	PyGILState_Release(gstate);

	return py_new_output_id;

err:
	PyGILState_Release(gstate);

	return NULL;
}

static int get_term_type(const char *v)
{
	switch (v[0]) {
	case 'h':
		return SRD_TERM_HIGH;
	case 'l':
		return SRD_TERM_LOW;
	case 'r':
		return SRD_TERM_RISING_EDGE;
	case 'f':
		return SRD_TERM_FALLING_EDGE;
	case 'e':
		return SRD_TERM_EITHER_EDGE;
	case 'n':
		return SRD_TERM_NO_EDGE;
	default:
		return -1;
	}

	return -1;
}

/**
 * Get the pin values at the current sample number.
 *
 * @param di The decoder instance to use. Must not be NULL.
 *           The number of channels must be >= 1.
 *
 * @return A newly allocated PyTuple containing the pin values at the
 *         current sample number.
 */
static PyObject *get_current_pinvalues(const struct srd_decoder_inst *di)
{
	int i;
	uint8_t sample;
	const uint8_t *sample_pos;
	int byte_offset, bit_offset;
	PyObject *py_pinvalues;
	PyGILState_STATE gstate;

	if (!di) {
		srd_err("Invalid decoder instance.");
		return NULL;
	}

	gstate = PyGILState_Ensure();

	py_pinvalues = PyTuple_New(di->dec_num_channels);

	for (i = 0; i < di->dec_num_channels; i++) {
		/* A channelmap value of -1 means "unused optional channel". */
		if (di->dec_channelmap[i] == -1) {
			/* Value of unused channel is 0xff, instead of 0 or 1. */
			PyTuple_SetItem(py_pinvalues, i, PyLong_FromLong(0xff));
		} else {
			sample_pos = di->inbuf + ((di->abs_cur_samplenum - di->abs_start_samplenum) * di->data_unitsize);
			byte_offset = di->dec_channelmap[i] / 8;
			bit_offset = di->dec_channelmap[i] % 8;
			sample = *(sample_pos + byte_offset) & (1 << bit_offset) ? 1 : 0;
			PyTuple_SetItem(py_pinvalues, i, PyLong_FromLong(sample));
		}
	}

	PyGILState_Release(gstate);

	return py_pinvalues;
}

/**
 * Create a list of terms in the specified condition.
 *
 * If there are no terms in the condition, 'term_list' will be NULL.
 *
 * @param py_dict A Python dict containing terms. Must not be NULL.
 * @param term_list Pointer to a GSList which will be set to the newly
 *                  created list of terms. Must not be NULL.
 *
 * @return SRD_OK upon success, a negative error code otherwise.
 */
static int create_term_list(PyObject *py_dict, GSList **term_list)
{
	Py_ssize_t pos = 0;
	PyObject *py_key, *py_value;
	struct srd_term *term;
	uint64_t num_samples_to_skip;
	char *term_str;
	PyGILState_STATE gstate;

	if (!py_dict || !term_list)
		return SRD_ERR_ARG;

	/* "Create" an empty GSList of terms. */
	*term_list = NULL;

	gstate = PyGILState_Ensure();

	/* Iterate over all items in the current dict. */
	while (PyDict_Next(py_dict, &pos, &py_key, &py_value)) {
		/* Check whether the current key is a string or a number. */
		if (PyLong_Check(py_key)) {
			/* The key is a number. */
			/* TODO: Check if the number is a valid channel. */
			/* Get the value string. */
			if ((py_pydictitem_as_str(py_dict, py_key, &term_str)) != SRD_OK) {
				srd_err("Failed to get the value.");
				goto err;
			}
			term = g_malloc(sizeof(struct srd_term));
			term->type = get_term_type(term_str);
			term->channel = PyLong_AsLong(py_key);
			g_free(term_str);
		} else if (PyUnicode_Check(py_key)) {
			/* The key is a string. */
			/* TODO: Check if it's "skip". */
			if ((py_pydictitem_as_long(py_dict, py_key, &num_samples_to_skip)) != SRD_OK) {
				srd_err("Failed to get number of samples to skip.");
				goto err;
			}
			term = g_malloc(sizeof(struct srd_term));
			term->type = SRD_TERM_SKIP;
			term->num_samples_to_skip = num_samples_to_skip;
			term->num_samples_already_skipped = 0;
		} else {
			srd_err("Term key is neither a string nor a number.");
			goto err;
		}

		/* Add the term to the list of terms. */
		*term_list = g_slist_append(*term_list, term);
	}

	PyGILState_Release(gstate);

	return SRD_OK;

err:
	PyGILState_Release(gstate);

	return SRD_ERR;
}

/**
 * Replace the current condition list with the new one.
 *
 * @param self TODO. Must not be NULL.
 * @param args TODO. Must not be NULL.
 *
 * @retval SRD_OK The new condition list was set successfully.
 * @retval SRD_ERR There was an error setting the new condition list.
 *                 The contents of di->condition_list are undefined.
 * @retval 9999 TODO.
 */
static int set_new_condition_list(PyObject *self, PyObject *args)
{
	struct srd_decoder_inst *di;
	GSList *term_list;
	PyObject *py_conditionlist, *py_conds, *py_dict;
	int i, num_conditions, ret;
	PyGILState_STATE gstate;

	if (!self || !args)
		return SRD_ERR_ARG;

	gstate = PyGILState_Ensure();

	/* Get the decoder instance. */
	if (!(di = srd_inst_find_by_obj(NULL, self))) {
		PyErr_SetString(PyExc_Exception, "decoder instance not found");
		goto err;
	}

	/*
	 * Return an error condition from .wait() when termination is
	 * requested, such that decode() will terminate.
	 */
	if (di->want_wait_terminate) {
		srd_dbg("%s: %s: Skip (want_term).", di->inst_id, __func__);
		goto err;
	}

	/*
	 * Parse the argument of self.wait() into 'py_conds', and check
	 * the data type. The argument is optional, None is assumed in
	 * its absence. None or an empty dict or an empty list mean that
	 * there is no condition, and the next available sample shall
	 * get returned to the caller.
	 */
	py_conds = Py_None;
	if (!PyArg_ParseTuple(args, "|O", &py_conds)) {
		/* Let Python raise this exception. */
		goto err;
	}
	if (py_conds == Py_None) {
		/* 'py_conds' is None. */
		goto ret_9999;
	} else if (PyList_Check(py_conds)) {
		/* 'py_conds' is a list. */
		py_conditionlist = py_conds;
		num_conditions = PyList_Size(py_conditionlist);
		if (num_conditions == 0)
			goto ret_9999; /* The PD invoked self.wait([]). */
		Py_IncRef(py_conditionlist);
	} else if (PyDict_Check(py_conds)) {
		/* 'py_conds' is a dict. */
		if (PyDict_Size(py_conds) == 0)
			goto ret_9999; /* The PD invoked self.wait({}). */
		/* Make a list and put the dict in there for convenience. */
		py_conditionlist = PyList_New(1);
		Py_IncRef(py_conds);
		PyList_SetItem(py_conditionlist, 0, py_conds);
		num_conditions = 1;
	} else {
		srd_err("Condition list is neither a list nor a dict.");
		goto err;
	}

	/* Free the old condition list. */
	condition_list_free(di);

	ret = SRD_OK;

	/* Iterate over the conditions, set di->condition_list accordingly. */
	for (i = 0; i < num_conditions; i++) {
		/* Get a condition (dict) from the condition list. */
		py_dict = PyList_GetItem(py_conditionlist, i);
		if (!PyDict_Check(py_dict)) {
			srd_err("Condition is not a dict.");
			ret = SRD_ERR;
			break;
		}

		/* Create the list of terms in this condition. */
		if ((ret = create_term_list(py_dict, &term_list)) < 0)
			break;

		/* Add the new condition to the PD instance's condition list. */
		di->condition_list = g_slist_append(di->condition_list, term_list);
	}

	Py_DecRef(py_conditionlist);

	PyGILState_Release(gstate);

	return ret;

err:
	PyGILState_Release(gstate);

	return SRD_ERR;

ret_9999:
	PyGILState_Release(gstate);

	return 9999;
}

/**
 * Create a SKIP condition list for condition-less .wait() calls.
 *
 * @param di Decoder instance.
 * @param count Number of samples to skip.
 *
 * @retval SRD_OK The new condition list was set successfully.
 * @retval SRD_ERR There was an error setting the new condition list.
 *                 The contents of di->condition_list are undefined.
 *
 * This routine is a reduced and specialized version of the @ref
 * set_new_condition_list() and @ref create_term_list() routines which
 * gets invoked when .wait() was called without specifications for
 * conditions. This minor duplication of the SKIP term list creation
 * simplifies the logic and avoids the creation of expensive Python
 * objects with "constant" values which the caller did not pass in the
 * first place. It results in maximum sharing of match handling code
 * paths.
 */
static int set_skip_condition(struct srd_decoder_inst *di, uint64_t count)
{
	struct srd_term *term;
	GSList *term_list;

	condition_list_free(di);
	term = g_malloc(sizeof(*term));
	term->type = SRD_TERM_SKIP;
	term->num_samples_to_skip = count;
	term->num_samples_already_skipped = 0;
	term_list = g_slist_append(NULL, term);
	di->condition_list = g_slist_append(di->condition_list, term_list);

	return SRD_OK;
}

static PyObject *Decoder_wait(PyObject *self, PyObject *args)
{
	int ret;
	uint64_t skip_count;
	unsigned int i;
	gboolean found_match;
	struct srd_decoder_inst *di;
	PyObject *py_pinvalues, *py_matched;
	PyGILState_STATE gstate;

	if (!self || !args)
		return NULL;

	gstate = PyGILState_Ensure();

	if (!(di = srd_inst_find_by_obj(NULL, self))) {
		PyErr_SetString(PyExc_Exception, "decoder instance not found");
		PyGILState_Release(gstate);
		Py_RETURN_NONE;
	}

	ret = set_new_condition_list(self, args);
	if (ret < 0) {
		srd_dbg("%s: %s: Aborting wait().", di->inst_id, __func__);
		goto err;
	}
	if (ret == 9999) {
		/*
		 * Empty condition list, automatic match. Arrange for the
		 * execution of regular match handling code paths such that
		 * the next available sample is returned to the caller.
		 * Make sure to skip one sample when "anywhere within the
		 * stream", yet make sure to not skip sample number 0.
		 */
		if (di->abs_cur_samplenum)
			skip_count = 1;
		else if (!di->condition_list)
			skip_count = 0;
		else
			skip_count = 1;
		ret = set_skip_condition(di, skip_count);
		if (ret < 0) {
			srd_dbg("%s: %s: Cannot setup condition-less wait().",
				di->inst_id, __func__);
			goto err;
		}
	}

	while (1) {

		Py_BEGIN_ALLOW_THREADS

		/* Wait for new samples to process, or termination request. */
		g_mutex_lock(&di->data_mutex);
		while (!di->got_new_samples && !di->want_wait_terminate)
			g_cond_wait(&di->got_new_samples_cond, &di->data_mutex);

		/*
		 * Check whether any of the current condition(s) match.
		 * Arrange for termination requests to take a code path which
		 * won't find new samples to process, pretends to have processed
		 * previously stored samples, and returns to the main thread,
		 * while the termination request still gets signalled.
		 */
		found_match = FALSE;

		/* Ignore return value for now, should never be negative. */
		(void)process_samples_until_condition_match(di, &found_match);

		Py_END_ALLOW_THREADS

		/* If there's a match, set self.samplenum etc. and return. */
		if (found_match) {
			/* Set self.samplenum to the (absolute) sample number that matched. */
			PyObject_SetAttrString(di->py_inst, "samplenum",
				PyLong_FromLong(di->abs_cur_samplenum));

			if (di->match_array && di->match_array->len > 0) {
				py_matched = PyTuple_New(di->match_array->len);
				for (i = 0; i < di->match_array->len; i++)
					PyTuple_SetItem(py_matched, i, PyBool_FromLong(di->match_array->data[i]));
				PyObject_SetAttrString(di->py_inst, "matched", py_matched);
				match_array_free(di);
			} else {
				PyObject_SetAttrString(di->py_inst, "matched", Py_None);
			}

			py_pinvalues = get_current_pinvalues(di);

			g_mutex_unlock(&di->data_mutex);

			PyGILState_Release(gstate);

			return py_pinvalues;
		}

		/* No match, reset state for the next chunk. */
		di->got_new_samples = FALSE;
		di->handled_all_samples = TRUE;
		di->abs_start_samplenum = 0;
		di->abs_end_samplenum = 0;
		di->inbuf = NULL;
		di->inbuflen = 0;

		/* Signal the main thread that we handled all samples. */
		g_cond_signal(&di->handled_all_samples_cond);

		/*
		 * When termination of wait() and decode() was requested,
		 * then exit the loop after releasing the mutex.
		 */
		if (di->want_wait_terminate) {
			srd_dbg("%s: %s: Will return from wait().",
				di->inst_id, __func__);
			g_mutex_unlock(&di->data_mutex);
			goto err;
		}

		g_mutex_unlock(&di->data_mutex);
	}

	PyGILState_Release(gstate);

	Py_RETURN_NONE;

err:
	PyGILState_Release(gstate);

	return NULL;
}

/**
 * Return whether the specified channel was supplied to the decoder.
 *
 * @param self TODO. Must not be NULL.
 * @param args TODO. Must not be NULL.
 *
 * @retval Py_True The channel has been supplied by the frontend.
 * @retval Py_False The channel has been supplied by the frontend.
 * @retval NULL An error occurred.
 */
static PyObject *Decoder_has_channel(PyObject *self, PyObject *args)
{
	int idx, count;
	struct srd_decoder_inst *di;
	PyGILState_STATE gstate;

	if (!self || !args)
		return NULL;

	gstate = PyGILState_Ensure();

	if (!(di = srd_inst_find_by_obj(NULL, self))) {
		PyErr_SetString(PyExc_Exception, "decoder instance not found");
		goto err;
	}

	/*
	 * Get the integer argument of self.has_channel(). Check for
	 * the range of supported PD input channel numbers.
	 */
	if (!PyArg_ParseTuple(args, "i", &idx)) {
		/* Let Python raise this exception. */
		goto err;
	}

	count = g_slist_length(di->decoder->channels) +
	        g_slist_length(di->decoder->opt_channels);
	if (idx < 0 || idx >= count) {
		srd_err("Invalid index %d, PD channel count %d.", idx, count);
		PyErr_SetString(PyExc_IndexError, "invalid channel index");
		goto err;
	}

	PyGILState_Release(gstate);

	return (di->dec_channelmap[idx] == -1) ? Py_False : Py_True;

err:
	PyGILState_Release(gstate);

	return NULL;
}

static PyMethodDef Decoder_methods[] = {
	{ "put", Decoder_put, METH_VARARGS,
	  "Accepts a dictionary with the following keys: startsample, endsample, data" },
	{ "register", (PyCFunction)Decoder_register, METH_VARARGS|METH_KEYWORDS,
			"Register a new output stream" },
	{ "wait", Decoder_wait, METH_VARARGS,
			"Wait for one or more conditions to occur" },
	{ "has_channel", Decoder_has_channel, METH_VARARGS,
			"Report whether a channel was supplied" },
	{NULL, NULL, 0, NULL}
};

/**
 * Create the sigrokdecode.Decoder type.
 *
 * @return The new type object.
 *
 * @private
 */
SRD_PRIV PyObject *srd_Decoder_type_new(void)
{
	PyType_Spec spec;
	PyType_Slot slots[] = {
		{ Py_tp_doc, "sigrok Decoder base class" },
		{ Py_tp_methods, Decoder_methods },
		{ Py_tp_new, (void *)&PyType_GenericNew },
		{ 0, NULL }
	};
	PyObject *py_obj;
	PyGILState_STATE gstate;

	gstate = PyGILState_Ensure();

	spec.name = "sigrokdecode.Decoder";
	spec.basicsize = sizeof(srd_Decoder);
	spec.itemsize = 0;
	spec.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE;
	spec.slots = slots;

	py_obj = PyType_FromSpec(&spec);

	PyGILState_Release(gstate);

	return py_obj;
}