libsigrokdecode  0.4.1
sigrok protocol decoding library
instance.c
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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 #include <inttypes.h>
26 #include <stdlib.h>
27 #include <stdint.h>
28 
29 /** @cond PRIVATE */
30 
31 extern SRD_PRIV GSList *sessions;
32 
33 /* module_sigrokdecode.c */
34 extern SRD_PRIV PyObject *srd_logic_type;
35 
36 /** @endcond */
37 
38 /**
39  * @file
40  *
41  * Decoder instance handling.
42  */
43 
44 /**
45  * @defgroup grp_instances Decoder instances
46  *
47  * Decoder instance handling.
48  *
49  * @{
50  */
51 
52 /**
53  * Set one or more options in a decoder instance.
54  *
55  * Handled options are removed from the hash.
56  *
57  * @param di Decoder instance.
58  * @param options A GHashTable of options to set.
59  *
60  * @return SRD_OK upon success, a (negative) error code otherwise.
61  *
62  * @since 0.1.0
63  */
65  GHashTable *options)
66 {
67  struct srd_decoder_option *sdo;
68  PyObject *py_di_options, *py_optval;
69  GVariant *value;
70  GSList *l;
71  double val_double;
72  gint64 val_int;
73  int ret;
74  const char *val_str;
75 
76  if (!di) {
77  srd_err("Invalid decoder instance.");
78  return SRD_ERR_ARG;
79  }
80 
81  if (!options) {
82  srd_err("Invalid options GHashTable.");
83  return SRD_ERR_ARG;
84  }
85 
86  if (!PyObject_HasAttrString(di->decoder->py_dec, "options")) {
87  /* Decoder has no options. */
88  if (g_hash_table_size(options) == 0) {
89  /* No options provided. */
90  return SRD_OK;
91  } else {
92  srd_err("Protocol decoder has no options.");
93  return SRD_ERR_ARG;
94  }
95  return SRD_OK;
96  }
97 
98  ret = SRD_ERR_PYTHON;
99  py_optval = NULL;
100 
101  /*
102  * The 'options' tuple is a class variable, but we need to
103  * change it. Changing it directly will affect the entire class,
104  * so we need to create a new object for it, and populate that
105  * instead.
106  */
107  if (!(py_di_options = PyObject_GetAttrString(di->py_inst, "options")))
108  goto err_out;
109  Py_DECREF(py_di_options);
110  py_di_options = PyDict_New();
111  PyObject_SetAttrString(di->py_inst, "options", py_di_options);
112 
113  for (l = di->decoder->options; l; l = l->next) {
114  sdo = l->data;
115  if ((value = g_hash_table_lookup(options, sdo->id))) {
116  /* A value was supplied for this option. */
117  if (!g_variant_type_equal(g_variant_get_type(value),
118  g_variant_get_type(sdo->def))) {
119  srd_err("Option '%s' should have the same type "
120  "as the default value.", sdo->id);
121  goto err_out;
122  }
123  } else {
124  /* Use default for this option. */
125  value = sdo->def;
126  }
127  if (g_variant_is_of_type(value, G_VARIANT_TYPE_STRING)) {
128  val_str = g_variant_get_string(value, NULL);
129  if (!(py_optval = PyUnicode_FromString(val_str))) {
130  /* Some UTF-8 encoding error. */
131  PyErr_Clear();
132  srd_err("Option '%s' requires a UTF-8 string value.", sdo->id);
133  goto err_out;
134  }
135  } else if (g_variant_is_of_type(value, G_VARIANT_TYPE_INT64)) {
136  val_int = g_variant_get_int64(value);
137  if (!(py_optval = PyLong_FromLong(val_int))) {
138  /* ValueError Exception */
139  PyErr_Clear();
140  srd_err("Option '%s' has invalid integer value.", sdo->id);
141  goto err_out;
142  }
143  } else if (g_variant_is_of_type(value, G_VARIANT_TYPE_DOUBLE)) {
144  val_double = g_variant_get_double(value);
145  if (!(py_optval = PyFloat_FromDouble(val_double))) {
146  /* ValueError Exception */
147  PyErr_Clear();
148  srd_err("Option '%s' has invalid float value.",
149  sdo->id);
150  goto err_out;
151  }
152  }
153  if (PyDict_SetItemString(py_di_options, sdo->id, py_optval) == -1)
154  goto err_out;
155  /* Not harmful even if we used the default. */
156  g_hash_table_remove(options, sdo->id);
157  }
158  if (g_hash_table_size(options) != 0)
159  srd_warn("Unknown options specified for '%s'", di->inst_id);
160 
161  ret = SRD_OK;
162 
163 err_out:
164  Py_XDECREF(py_optval);
165  if (PyErr_Occurred()) {
166  srd_exception_catch("Stray exception in srd_inst_option_set()");
167  ret = SRD_ERR_PYTHON;
168  }
169 
170  return ret;
171 }
172 
173 /* Helper GComparefunc for g_slist_find_custom() in srd_inst_channel_set_all() */
174 static gint compare_channel_id(const struct srd_channel *pdch,
175  const char *channel_id)
176 {
177  return strcmp(pdch->id, channel_id);
178 }
179 
180 /**
181  * Set all channels in a decoder instance.
182  *
183  * This function sets _all_ channels for the specified decoder instance, i.e.,
184  * it overwrites any channels that were already defined (if any).
185  *
186  * @param di Decoder instance.
187  * @param new_channels A GHashTable of channels to set. Key is channel name,
188  * value is the channel number. Samples passed to this
189  * instance will be arranged in this order.
190  *
191  * @return SRD_OK upon success, a (negative) error code otherwise.
192  *
193  * @since 0.4.0
194  */
196  GHashTable *new_channels)
197 {
198  GVariant *channel_val;
199  GList *l;
200  GSList *sl;
201  struct srd_channel *pdch;
202  int *new_channelmap, new_channelnum, num_required_channels, i;
203  char *channel_id;
204 
205  srd_dbg("Setting channels for instance %s with list of %d channels.",
206  di->inst_id, g_hash_table_size(new_channels));
207 
208  if (g_hash_table_size(new_channels) == 0)
209  /* No channels provided. */
210  return SRD_OK;
211 
212  if (di->dec_num_channels == 0) {
213  /* Decoder has no channels. */
214  srd_err("Protocol decoder %s has no channels to define.",
215  di->decoder->name);
216  return SRD_ERR_ARG;
217  }
218 
219  new_channelmap = g_malloc(sizeof(int) * di->dec_num_channels);
220 
221  /*
222  * For now, map all indexes to channel -1 (can be overridden later).
223  * This -1 is interpreted as an unspecified channel later.
224  */
225  for (i = 0; i < di->dec_num_channels; i++)
226  new_channelmap[i] = -1;
227 
228  for (l = g_hash_table_get_keys(new_channels); l; l = l->next) {
229  channel_id = l->data;
230  channel_val = g_hash_table_lookup(new_channels, channel_id);
231  if (!g_variant_is_of_type(channel_val, G_VARIANT_TYPE_INT32)) {
232  /* Channel name was specified without a value. */
233  srd_err("No channel number was specified for %s.",
234  channel_id);
235  g_free(new_channelmap);
236  return SRD_ERR_ARG;
237  }
238  new_channelnum = g_variant_get_int32(channel_val);
239  if (!(sl = g_slist_find_custom(di->decoder->channels, channel_id,
240  (GCompareFunc)compare_channel_id))) {
241  /* Fall back on optional channels. */
242  if (!(sl = g_slist_find_custom(di->decoder->opt_channels,
243  channel_id, (GCompareFunc)compare_channel_id))) {
244  srd_err("Protocol decoder %s has no channel "
245  "'%s'.", di->decoder->name, channel_id);
246  g_free(new_channelmap);
247  return SRD_ERR_ARG;
248  }
249  }
250  pdch = sl->data;
251  new_channelmap[pdch->order] = new_channelnum;
252  srd_dbg("Setting channel mapping: %s (index %d) = channel %d.",
253  pdch->id, pdch->order, new_channelnum);
254  }
255 
256  srd_dbg("Final channel map:");
257  num_required_channels = g_slist_length(di->decoder->channels);
258  for (i = 0; i < di->dec_num_channels; i++) {
259  srd_dbg(" - index %d = channel %d (%s)", i, new_channelmap[i],
260  (i < num_required_channels) ? "required" : "optional");
261  }
262 
263  /* Report an error if not all required channels were specified. */
264  for (i = 0; i < num_required_channels; i++) {
265  if (new_channelmap[i] != -1)
266  continue;
267  pdch = g_slist_nth(di->decoder->channels, i)->data;
268  srd_err("Required channel '%s' (index %d) was not specified.",
269  pdch->id, i);
270  return SRD_ERR;
271  }
272 
273  g_free(di->dec_channelmap);
274  di->dec_channelmap = new_channelmap;
275 
276  return SRD_OK;
277 }
278 
279 /**
280  * Create a new protocol decoder instance.
281  *
282  * @param sess The session holding the protocol decoder instance.
283  * @param decoder_id Decoder 'id' field.
284  * @param options GHashtable of options which override the defaults set in
285  * the decoder class. May be NULL.
286  *
287  * @return Pointer to a newly allocated struct srd_decoder_inst, or
288  * NULL in case of failure.
289  *
290  * @since 0.3.0
291  */
292 SRD_API struct srd_decoder_inst *srd_inst_new(struct srd_session *sess,
293  const char *decoder_id, GHashTable *options)
294 {
295  int i;
296  struct srd_decoder *dec;
297  struct srd_decoder_inst *di;
298  char *inst_id;
299 
300  srd_dbg("Creating new %s instance.", decoder_id);
301 
302  if (session_is_valid(sess) != SRD_OK) {
303  srd_err("Invalid session.");
304  return NULL;
305  }
306 
307  if (!(dec = srd_decoder_get_by_id(decoder_id))) {
308  srd_err("Protocol decoder %s not found.", decoder_id);
309  return NULL;
310  }
311 
312  di = g_malloc0(sizeof(struct srd_decoder_inst));
313 
314  di->decoder = dec;
315  di->sess = sess;
316  if (options) {
317  inst_id = g_hash_table_lookup(options, "id");
318  di->inst_id = g_strdup(inst_id ? inst_id : decoder_id);
319  g_hash_table_remove(options, "id");
320  } else
321  di->inst_id = g_strdup(decoder_id);
322 
323  /*
324  * Prepare a default channel map, where samples come in the
325  * order in which the decoder class defined them.
326  */
327  di->dec_num_channels = g_slist_length(di->decoder->channels) +
328  g_slist_length(di->decoder->opt_channels);
329  if (di->dec_num_channels) {
330  di->dec_channelmap =
331  g_malloc(sizeof(int) * di->dec_num_channels);
332  for (i = 0; i < di->dec_num_channels; i++)
333  di->dec_channelmap[i] = i;
334  /*
335  * Will be used to prepare a sample at every iteration
336  * of the instance's decode() method.
337  */
338  di->channel_samples = g_malloc(di->dec_num_channels);
339  }
340 
341  /* Create a new instance of this decoder class. */
342  if (!(di->py_inst = PyObject_CallObject(dec->py_dec, NULL))) {
343  if (PyErr_Occurred())
344  srd_exception_catch("Failed to create %s instance",
345  decoder_id);
346  g_free(di->dec_channelmap);
347  g_free(di);
348  return NULL;
349  }
350 
351  if (options && srd_inst_option_set(di, options) != SRD_OK) {
352  g_free(di->dec_channelmap);
353  g_free(di);
354  return NULL;
355  }
356 
357  /* Instance takes input from a frontend by default. */
358  sess->di_list = g_slist_append(sess->di_list, di);
359 
360  return di;
361 }
362 
363 /**
364  * Stack a decoder instance on top of another.
365  *
366  * @param sess The session holding the protocol decoder instances.
367  * @param di_bottom The instance on top of which di_top will be stacked.
368  * @param di_top The instance to go on top.
369  *
370  * @return SRD_OK upon success, a (negative) error code otherwise.
371  *
372  * @since 0.3.0
373  */
374 SRD_API int srd_inst_stack(struct srd_session *sess,
375  struct srd_decoder_inst *di_bottom,
376  struct srd_decoder_inst *di_top)
377 {
378 
379  if (session_is_valid(sess) != SRD_OK) {
380  srd_err("Invalid session.");
381  return SRD_ERR_ARG;
382  }
383 
384  if (!di_bottom || !di_top) {
385  srd_err("Invalid from/to instance pair.");
386  return SRD_ERR_ARG;
387  }
388 
389  if (g_slist_find(sess->di_list, di_top)) {
390  /* Remove from the unstacked list. */
391  sess->di_list = g_slist_remove(sess->di_list, di_top);
392  }
393 
394  /* Stack on top of source di. */
395  di_bottom->next_di = g_slist_append(di_bottom->next_di, di_top);
396 
397  srd_dbg("Stacked %s onto %s.", di_top->inst_id, di_bottom->inst_id);
398 
399  return SRD_OK;
400 }
401 
402 /**
403  * Find a decoder instance by its instance ID.
404  *
405  * Only the bottom level of instances are searched -- instances already stacked
406  * on top of another one will not be found.
407  *
408  * @param sess The session holding the protocol decoder instance.
409  * @param inst_id The instance ID to be found.
410  *
411  * @return Pointer to struct srd_decoder_inst, or NULL if not found.
412  *
413  * @since 0.3.0
414  */
415 SRD_API struct srd_decoder_inst *srd_inst_find_by_id(struct srd_session *sess,
416  const char *inst_id)
417 {
418  GSList *l;
419  struct srd_decoder_inst *tmp, *di;
420 
421  if (session_is_valid(sess) != SRD_OK) {
422  srd_err("Invalid session.");
423  return NULL;
424  }
425 
426  di = NULL;
427  for (l = sess->di_list; l; l = l->next) {
428  tmp = l->data;
429  if (!strcmp(tmp->inst_id, inst_id)) {
430  di = tmp;
431  break;
432  }
433  }
434 
435  return di;
436 }
437 
438 static struct srd_decoder_inst *srd_sess_inst_find_by_obj(
439  struct srd_session *sess, const GSList *stack,
440  const PyObject *obj)
441 {
442  const GSList *l;
443  struct srd_decoder_inst *tmp, *di;
444 
445  if (session_is_valid(sess) != SRD_OK) {
446  srd_err("Invalid session.");
447  return NULL;
448  }
449 
450  di = NULL;
451  for (l = stack ? stack : sess->di_list; di == NULL && l != NULL; l = l->next) {
452  tmp = l->data;
453  if (tmp->py_inst == obj)
454  di = tmp;
455  else if (tmp->next_di)
456  di = srd_sess_inst_find_by_obj(sess, tmp->next_di, obj);
457  }
458 
459  return di;
460 }
461 
462 /**
463  * Find a decoder instance by its Python object.
464  *
465  * I.e. find that instance's instantiation of the sigrokdecode.Decoder class.
466  * This will recurse to find the instance anywhere in the stack tree of all
467  * sessions.
468  *
469  * @param stack Pointer to a GSList of struct srd_decoder_inst, indicating the
470  * stack to search. To start searching at the bottom level of
471  * decoder instances, pass NULL.
472  * @param obj The Python class instantiation.
473  *
474  * @return Pointer to struct srd_decoder_inst, or NULL if not found.
475  *
476  * @private
477  *
478  * @since 0.1.0
479  */
480 SRD_PRIV struct srd_decoder_inst *srd_inst_find_by_obj(const GSList *stack,
481  const PyObject *obj)
482 {
483  struct srd_decoder_inst *di;
484  struct srd_session *sess;
485  GSList *l;
486 
487  di = NULL;
488  for (l = sessions; di == NULL && l != NULL; l = l->next) {
489  sess = l->data;
490  di = srd_sess_inst_find_by_obj(sess, stack, obj);
491  }
492 
493  return di;
494 }
495 
496 /** @private */
497 SRD_PRIV int srd_inst_start(struct srd_decoder_inst *di)
498 {
499  PyObject *py_res;
500  GSList *l;
501  struct srd_decoder_inst *next_di;
502  int ret;
503 
504  srd_dbg("Calling start() method on protocol decoder instance %s.",
505  di->inst_id);
506 
507  if (!(py_res = PyObject_CallMethod(di->py_inst, "start", NULL))) {
508  srd_exception_catch("Protocol decoder instance %s",
509  di->inst_id);
510  return SRD_ERR_PYTHON;
511  }
512  Py_DecRef(py_res);
513 
514  /* Start all the PDs stacked on top of this one. */
515  for (l = di->next_di; l; l = l->next) {
516  next_di = l->data;
517  if ((ret = srd_inst_start(next_di)) != SRD_OK)
518  return ret;
519  }
520 
521  return SRD_OK;
522 }
523 
524 /**
525  * Decode a chunk of samples.
526  *
527  * @param di The decoder instance to call. Must not be NULL.
528  * @param start_samplenum The starting sample number for the buffer's sample
529  * set, relative to the start of capture.
530  * @param end_samplenum The ending sample number for the buffer's sample
531  * set, relative to the start of capture.
532  * @param inbuf The buffer to decode. Must not be NULL.
533  * @param inbuflen Length of the buffer. Must be > 0.
534  * @param unitsize The number of bytes per sample. Must be > 0.
535  *
536  * @return SRD_OK upon success, a (negative) error code otherwise.
537  *
538  * @private
539  */
540 SRD_PRIV int srd_inst_decode(const struct srd_decoder_inst *di,
541  uint64_t start_samplenum, uint64_t end_samplenum,
542  const uint8_t *inbuf, uint64_t inbuflen, uint64_t unitsize)
543 {
544  PyObject *py_res;
545  srd_logic *logic;
546  long apiver;
547 
548  /* Return an error upon unusable input. */
549  if (!di) {
550  srd_dbg("empty decoder instance");
551  return SRD_ERR_ARG;
552  }
553  if (!inbuf) {
554  srd_dbg("NULL buffer pointer");
555  return SRD_ERR_ARG;
556  }
557  if (inbuflen == 0) {
558  srd_dbg("empty buffer");
559  return SRD_ERR_ARG;
560  }
561  if (unitsize == 0) {
562  srd_dbg("unitsize 0");
563  return SRD_ERR_ARG;
564  }
565 
566  ((struct srd_decoder_inst *)di)->data_unitsize = unitsize;
567 
568  srd_dbg("Decoding: start sample %" PRIu64 ", end sample %"
569  PRIu64 " (%" PRIu64 " samples, %" PRIu64 " bytes, unitsize = "
570  "%d), instance %s.", start_samplenum, end_samplenum,
571  end_samplenum - start_samplenum, inbuflen, di->data_unitsize,
572  di->inst_id);
573 
574  apiver = srd_decoder_apiver(di->decoder);
575 
576  if (apiver == 2) {
577  /*
578  * Create new srd_logic object. Each iteration around the PD's
579  * loop will fill one sample into this object.
580  */
581  logic = PyObject_New(srd_logic, (PyTypeObject *)srd_logic_type);
582  Py_INCREF(logic);
583  logic->di = (struct srd_decoder_inst *)di;
584  logic->start_samplenum = start_samplenum;
585  logic->itercnt = 0;
586  logic->inbuf = (uint8_t *)inbuf;
587  logic->inbuflen = inbuflen;
588  logic->sample = PyList_New(2);
589  Py_INCREF(logic->sample);
590 
591  Py_IncRef(di->py_inst);
592  if (!(py_res = PyObject_CallMethod(di->py_inst, "decode",
593  "KKO", start_samplenum, end_samplenum, logic))) {
594  srd_exception_catch("Protocol decoder instance %s",
595  di->inst_id);
596  return SRD_ERR_PYTHON;
597  }
598  Py_DecRef(py_res);
599  }
600 
601  return SRD_OK;
602 }
603 
604 /** @private */
605 SRD_PRIV void srd_inst_free(struct srd_decoder_inst *di)
606 {
607  GSList *l;
608  struct srd_pd_output *pdo;
609 
610  srd_dbg("Freeing instance %s", di->inst_id);
611 
612  Py_DecRef(di->py_inst);
613  g_free(di->inst_id);
614  g_free(di->dec_channelmap);
615  g_free(di->channel_samples);
616  g_slist_free(di->next_di);
617  for (l = di->pd_output; l; l = l->next) {
618  pdo = l->data;
619  g_free(pdo->proto_id);
620  g_free(pdo);
621  }
622  g_slist_free(di->pd_output);
623  g_free(di);
624 }
625 
626 /** @private */
627 SRD_PRIV void srd_inst_free_all(struct srd_session *sess, GSList *stack)
628 {
629  GSList *l;
630  struct srd_decoder_inst *di;
631 
632  if (session_is_valid(sess) != SRD_OK) {
633  srd_err("Invalid session.");
634  return;
635  }
636 
637  di = NULL;
638  for (l = stack ? stack : sess->di_list; di == NULL && l != NULL; l = l->next) {
639  di = l->data;
640  if (di->next_di)
641  srd_inst_free_all(sess, di->next_di);
642  srd_inst_free(di);
643  }
644  if (!stack) {
645  g_slist_free(sess->di_list);
646  sess->di_list = NULL;
647  }
648 }
649 
650 /** @} */
No error.
struct srd_decoder * decoder
Function argument error.
struct srd_decoder * srd_decoder_get_by_id(const char *id)
Get the decoder with the specified ID.
Definition: decoder.c:89
struct srd_session * sess
int srd_inst_option_set(struct srd_decoder_inst *di, GHashTable *options)
Set one or more options in a decoder instance.
Definition: instance.c:64
int order
The index of the channel, i.e.
Structure which contains information about one protocol decoder channel.
#define SRD_API
Generic/unspecified error.
GSList * opt_channels
List of optional channels for this decoder.
void * py_dec
sigrokdecode.Decoder class.
char * id
The ID of the channel.
The public libsigrokdecode header file to be used by frontends.
int srd_inst_stack(struct srd_session *sess, struct srd_decoder_inst *di_bottom, struct srd_decoder_inst *di_top)
Stack a decoder instance on top of another.
Definition: instance.c:374
char * name
The (short) decoder name.
GSList * options
List of decoder options.
struct srd_decoder_inst * srd_inst_find_by_id(struct srd_session *sess, const char *inst_id)
Find a decoder instance by its instance ID.
Definition: instance.c:415
#define SRD_PRIV
GSList * channels
List of channels required by this decoder.
struct srd_decoder_inst * srd_inst_new(struct srd_session *sess, const char *decoder_id, GHashTable *options)
Create a new protocol decoder instance.
Definition: instance.c:292
SRD_PRIV long srd_decoder_apiver(const struct srd_decoder *d)
Get the API version of the specified decoder.
Definition: decoder.c:596
int srd_inst_channel_set_all(struct srd_decoder_inst *di, GHashTable *new_channels)
Set all channels in a decoder instance.
Definition: instance.c:195
Python C API error.
uint8_t * channel_samples