libsigrokdecode  0.3.1
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 "libsigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
22 #include "libsigrokdecode-internal.h"
23 #include "config.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 /* type_logic.c */
34 extern SRD_PRIV PyTypeObject 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.", sdo->id);
149  goto err_out;
150  }
151  }
152  if (PyDict_SetItemString(py_di_options, sdo->id, py_optval) == -1)
153  goto err_out;
154  /* Not harmful even if we used the default. */
155  g_hash_table_remove(options, sdo->id);
156  }
157  if (g_hash_table_size(options) != 0)
158  srd_warn("Unknown options specified for '%s'", di->inst_id);
159 
160  ret = SRD_OK;
161 
162 err_out:
163  Py_XDECREF(py_optval);
164  if (PyErr_Occurred()) {
165  srd_exception_catch("Stray exception in srd_inst_option_set().");
166  ret = SRD_ERR_PYTHON;
167  }
168 
169  return ret;
170 }
171 
172 /* Helper GComparefunc for g_slist_find_custom() in srd_inst_channel_set_all() */
173 static gint compare_channel_id(const struct srd_channel *pdch,
174  const char *channel_id)
175 {
176  return strcmp(pdch->id, channel_id);
177 }
178 
179 /**
180  * Set all channels in a decoder instance.
181  *
182  * This function sets _all_ channels for the specified decoder instance, i.e.,
183  * it overwrites any channels that were already defined (if any).
184  *
185  * @param di Decoder instance.
186  * @param new_channels A GHashTable of channels to set. Key is channel name,
187  * value is the channel number. Samples passed to this
188  * instance will be arranged in this order.
189  * @param unit_size Number of bytes per sample in the data stream to be passed
190  * to the decoder. The highest channel index specified in the
191  * channel map must lie within a sample unit.
192  *
193  * @return SRD_OK upon success, a (negative) error code otherwise.
194  *
195  * @since 0.3.0
196  */
198  GHashTable *new_channels, int unit_size)
199 {
200  GVariant *channel_val;
201  GList *l;
202  GSList *sl;
203  struct srd_channel *pdch;
204  int *new_channelmap, new_channelnum, num_required_channels, i;
205  char *channel_id;
206 
207  srd_dbg("Setting channels for instance %s with list of %d channels, "
208  "unitsize %d.", di->inst_id, g_hash_table_size(new_channels), unit_size);
209 
210  if (g_hash_table_size(new_channels) == 0)
211  /* No channels provided. */
212  return SRD_OK;
213 
214  if (di->dec_num_channels == 0) {
215  /* Decoder has no channels. */
216  srd_err("Protocol decoder %s has no channels to define.",
217  di->decoder->name);
218  return SRD_ERR_ARG;
219  }
220 
221  new_channelmap = NULL;
222 
223  if (!(new_channelmap = g_try_malloc(sizeof(int) * di->dec_num_channels))) {
224  srd_err("Failed to g_malloc() new channel map.");
225  return SRD_ERR_MALLOC;
226  }
227 
228  /*
229  * For now, map all indexes to channel -1 (can be overridden later).
230  * This -1 is interpreted as an unspecified channel later.
231  */
232  for (i = 0; i < di->dec_num_channels; i++)
233  new_channelmap[i] = -1;
234 
235  for (l = g_hash_table_get_keys(new_channels); l; l = l->next) {
236  channel_id = l->data;
237  channel_val = g_hash_table_lookup(new_channels, channel_id);
238  if (!g_variant_is_of_type(channel_val, G_VARIANT_TYPE_INT32)) {
239  /* Channel name was specified without a value. */
240  srd_err("No channel number was specified for %s.",
241  channel_id);
242  g_free(new_channelmap);
243  return SRD_ERR_ARG;
244  }
245  new_channelnum = g_variant_get_int32(channel_val);
246  if (new_channelnum >= 8 * unit_size) {
247  srd_err("Channel index %d not within data unit (%d bit).",
248  new_channelnum, 8 * unit_size);
249  g_free(new_channelmap);
250  return SRD_ERR_ARG;
251  }
252  if (!(sl = g_slist_find_custom(di->decoder->channels, channel_id,
253  (GCompareFunc)compare_channel_id))) {
254  /* Fall back on optional channels. */
255  if (!(sl = g_slist_find_custom(di->decoder->opt_channels,
256  channel_id, (GCompareFunc) compare_channel_id))) {
257  srd_err("Protocol decoder %s has no channel "
258  "'%s'.", di->decoder->name, channel_id);
259  g_free(new_channelmap);
260  return SRD_ERR_ARG;
261  }
262  }
263  pdch = sl->data;
264  new_channelmap[pdch->order] = new_channelnum;
265  srd_dbg("Setting channel mapping: %s (index %d) = channel %d.",
266  pdch->id, pdch->order, new_channelnum);
267  }
268  di->data_unitsize = unit_size;
269 
270  srd_dbg("Final channel map:");
271  num_required_channels = g_slist_length(di->decoder->channels);
272  for (i = 0; i < di->dec_num_channels; i++) {
273  srd_dbg(" - index %d = channel %d (%s)", i, new_channelmap[i],
274  (i < num_required_channels) ? "required" : "optional");
275  }
276 
277  /* Report an error if not all required channels were specified. */
278  for (i = 0; i < num_required_channels; i++) {
279  if (new_channelmap[i] != -1)
280  continue;
281  pdch = g_slist_nth(di->decoder->channels, i)->data;
282  srd_err("Required channel '%s' (index %d) was not specified.",
283  pdch->id, i);
284  return SRD_ERR;
285  }
286 
287  g_free(di->dec_channelmap);
288  di->dec_channelmap = new_channelmap;
289 
290  return SRD_OK;
291 }
292 
293 /**
294  * Create a new protocol decoder instance.
295  *
296  * @param sess The session holding the protocol decoder instance.
297  * @param decoder_id Decoder 'id' field.
298  * @param options GHashtable of options which override the defaults set in
299  * the decoder class. May be NULL.
300  *
301  * @return Pointer to a newly allocated struct srd_decoder_inst, or
302  * NULL in case of failure.
303  *
304  * @since 0.3.0
305  */
306 SRD_API struct srd_decoder_inst *srd_inst_new(struct srd_session *sess,
307  const char *decoder_id, GHashTable *options)
308 {
309  int i;
310  struct srd_decoder *dec;
311  struct srd_decoder_inst *di;
312  char *inst_id;
313 
314  srd_dbg("Creating new %s instance.", decoder_id);
315 
316  if (session_is_valid(sess) != SRD_OK) {
317  srd_err("Invalid session.");
318  return NULL;
319  }
320 
321  if (!(dec = srd_decoder_get_by_id(decoder_id))) {
322  srd_err("Protocol decoder %s not found.", decoder_id);
323  return NULL;
324  }
325 
326  if (!(di = g_try_malloc0(sizeof(struct srd_decoder_inst)))) {
327  srd_err("Failed to g_malloc() instance.");
328  return NULL;
329  }
330 
331  di->decoder = dec;
332  di->sess = sess;
333  if (options) {
334  inst_id = g_hash_table_lookup(options, "id");
335  di->inst_id = g_strdup(inst_id ? inst_id : decoder_id);
336  g_hash_table_remove(options, "id");
337  } else
338  di->inst_id = g_strdup(decoder_id);
339 
340  /*
341  * Prepare a default channel map, where samples come in the
342  * order in which the decoder class defined them.
343  */
344  di->dec_num_channels = g_slist_length(di->decoder->channels) +
345  g_slist_length(di->decoder->opt_channels);
346  if (di->dec_num_channels) {
347  if (!(di->dec_channelmap =
348  g_try_malloc(sizeof(int) * di->dec_num_channels))) {
349  srd_err("Failed to g_malloc() channel map.");
350  g_free(di);
351  return NULL;
352  }
353  for (i = 0; i < di->dec_num_channels; i++)
354  di->dec_channelmap[i] = i;
355  di->data_unitsize = (di->dec_num_channels + 7) / 8;
356  /*
357  * Will be used to prepare a sample at every iteration
358  * of the instance's decode() method.
359  */
360  if (!(di->channel_samples = g_try_malloc(di->dec_num_channels))) {
361  srd_err("Failed to g_malloc() sample buffer.");
362  g_free(di->dec_channelmap);
363  g_free(di);
364  return NULL;
365  }
366  }
367 
368  /* Create a new instance of this decoder class. */
369  if (!(di->py_inst = PyObject_CallObject(dec->py_dec, NULL))) {
370  if (PyErr_Occurred())
371  srd_exception_catch("failed to create %s instance: ",
372  decoder_id);
373  g_free(di->dec_channelmap);
374  g_free(di);
375  return NULL;
376  }
377 
378  if (options && srd_inst_option_set(di, options) != SRD_OK) {
379  g_free(di->dec_channelmap);
380  g_free(di);
381  return NULL;
382  }
383 
384  /* Instance takes input from a frontend by default. */
385  sess->di_list = g_slist_append(sess->di_list, di);
386 
387  return di;
388 }
389 
390 /**
391  * Stack a decoder instance on top of another.
392  *
393  * @param sess The session holding the protocol decoder instances.
394  * @param di_bottom The instance on top of which di_top will be stacked.
395  * @param di_top The instance to go on top.
396  *
397  * @return SRD_OK upon success, a (negative) error code otherwise.
398  *
399  * @since 0.3.0
400  */
401 SRD_API int srd_inst_stack(struct srd_session *sess,
402  struct srd_decoder_inst *di_bottom,
403  struct srd_decoder_inst *di_top)
404 {
405 
406  if (session_is_valid(sess) != SRD_OK) {
407  srd_err("Invalid session.");
408  return SRD_ERR_ARG;
409  }
410 
411  if (!di_bottom || !di_top) {
412  srd_err("Invalid from/to instance pair.");
413  return SRD_ERR_ARG;
414  }
415 
416  if (g_slist_find(sess->di_list, di_top)) {
417  /* Remove from the unstacked list. */
418  sess->di_list = g_slist_remove(sess->di_list, di_top);
419  }
420 
421  /* Stack on top of source di. */
422  di_bottom->next_di = g_slist_append(di_bottom->next_di, di_top);
423 
424  srd_dbg("Stacked %s on top of %s.", di_top->inst_id, di_bottom->inst_id);
425 
426  return SRD_OK;
427 }
428 
429 /**
430  * Find a decoder instance by its instance ID.
431  *
432  * Only the bottom level of instances are searched -- instances already stacked
433  * on top of another one will not be found.
434  *
435  * @param sess The session holding the protocol decoder instance.
436  * @param inst_id The instance ID to be found.
437  *
438  * @return Pointer to struct srd_decoder_inst, or NULL if not found.
439  *
440  * @since 0.3.0
441  */
442 SRD_API struct srd_decoder_inst *srd_inst_find_by_id(struct srd_session *sess,
443  const char *inst_id)
444 {
445  GSList *l;
446  struct srd_decoder_inst *tmp, *di;
447 
448  if (session_is_valid(sess) != SRD_OK) {
449  srd_err("Invalid session.");
450  return NULL;
451  }
452 
453  di = NULL;
454  for (l = sess->di_list; l; l = l->next) {
455  tmp = l->data;
456  if (!strcmp(tmp->inst_id, inst_id)) {
457  di = tmp;
458  break;
459  }
460  }
461 
462  return di;
463 }
464 
465 static struct srd_decoder_inst *srd_sess_inst_find_by_obj(
466  struct srd_session *sess, const GSList *stack,
467  const PyObject *obj)
468 {
469  const GSList *l;
470  struct srd_decoder_inst *tmp, *di;
471 
472  if (session_is_valid(sess) != SRD_OK) {
473  srd_err("Invalid session.");
474  return NULL;
475  }
476 
477  di = NULL;
478  for (l = stack ? stack : sess->di_list; di == NULL && l != NULL; l = l->next) {
479  tmp = l->data;
480  if (tmp->py_inst == obj)
481  di = tmp;
482  else if (tmp->next_di)
483  di = srd_sess_inst_find_by_obj(sess, tmp->next_di, obj);
484  }
485 
486  return di;
487 }
488 
489 /**
490  * Find a decoder instance by its Python object.
491  *
492  * I.e. find that instance's instantiation of the sigrokdecode.Decoder class.
493  * This will recurse to find the instance anywhere in the stack tree of all
494  * sessions.
495  *
496  * @param stack Pointer to a GSList of struct srd_decoder_inst, indicating the
497  * stack to search. To start searching at the bottom level of
498  * decoder instances, pass NULL.
499  * @param obj The Python class instantiation.
500  *
501  * @return Pointer to struct srd_decoder_inst, or NULL if not found.
502  *
503  * @private
504  *
505  * @since 0.1.0
506  */
507 SRD_PRIV struct srd_decoder_inst *srd_inst_find_by_obj(const GSList *stack,
508  const PyObject *obj)
509 {
510  struct srd_decoder_inst *di;
511  struct srd_session *sess;
512  GSList *l;
513 
514  di = NULL;
515  for (l = sessions; di == NULL && l != NULL; l = l->next) {
516  sess = l->data;
517  di = srd_sess_inst_find_by_obj(sess, stack, obj);
518  }
519 
520  return di;
521 }
522 
523 /** @private */
524 SRD_PRIV int srd_inst_start(struct srd_decoder_inst *di)
525 {
526  PyObject *py_res;
527  GSList *l;
528  struct srd_decoder_inst *next_di;
529  int ret;
530 
531  srd_dbg("Calling start() method on protocol decoder instance %s.",
532  di->inst_id);
533 
534  if (!(py_res = PyObject_CallMethod(di->py_inst, "start", NULL))) {
535  srd_exception_catch("Protocol decoder instance %s: ",
536  di->inst_id);
537  return SRD_ERR_PYTHON;
538  }
539  Py_DecRef(py_res);
540 
541  /* Start all the PDs stacked on top of this one. */
542  for (l = di->next_di; l; l = l->next) {
543  next_di = l->data;
544  if ((ret = srd_inst_start(next_di)) != SRD_OK)
545  return ret;
546  }
547 
548  return SRD_OK;
549 }
550 
551 /**
552  * Run the specified decoder function.
553  *
554  * @param di The decoder instance to call. Must not be NULL.
555  * @param start_samplenum The starting sample number for the buffer's sample
556  * set, relative to the start of capture.
557  * @param end_samplenum The ending sample number for the buffer's sample
558  * set, relative to the start of capture.
559  * @param inbuf The buffer to decode. Must not be NULL.
560  * @param inbuflen Length of the buffer. Must be > 0.
561  *
562  * @return SRD_OK upon success, a (negative) error code otherwise.
563  *
564  * @private
565  *
566  * @since 0.1.0
567  */
568 SRD_PRIV int srd_inst_decode(const struct srd_decoder_inst *di,
569  uint64_t start_samplenum, uint64_t end_samplenum,
570  const uint8_t *inbuf, uint64_t inbuflen)
571 {
572  PyObject *py_res;
573  srd_logic *logic;
574 
575  srd_dbg("Calling decode() on instance %s with %" PRIu64 " bytes "
576  "starting at sample %" PRIu64 ".", di->inst_id, inbuflen,
577  start_samplenum);
578 
579  /* Return an error upon unusable input. */
580  if (!di) {
581  srd_dbg("empty decoder instance");
582  return SRD_ERR_ARG;
583  }
584  if (!inbuf) {
585  srd_dbg("NULL buffer pointer");
586  return SRD_ERR_ARG;
587  }
588  if (inbuflen == 0) {
589  srd_dbg("empty buffer");
590  return SRD_ERR_ARG;
591  }
592 
593  /*
594  * Create new srd_logic object. Each iteration around the PD's loop
595  * will fill one sample into this object.
596  */
597  logic = PyObject_New(srd_logic, &srd_logic_type);
598  Py_INCREF(logic);
599  logic->di = (struct srd_decoder_inst *)di;
600  logic->start_samplenum = start_samplenum;
601  logic->itercnt = 0;
602  logic->inbuf = (uint8_t *)inbuf;
603  logic->inbuflen = inbuflen;
604  logic->sample = PyList_New(2);
605  Py_INCREF(logic->sample);
606 
607  Py_IncRef(di->py_inst);
608  if (!(py_res = PyObject_CallMethod(di->py_inst, "decode",
609  "KKO", start_samplenum, end_samplenum, logic))) {
610  srd_exception_catch("Protocol decoder instance %s: ", di->inst_id);
611  return SRD_ERR_PYTHON;
612  }
613  Py_DecRef(py_res);
614 
615  return SRD_OK;
616 }
617 
618 /** @private */
619 SRD_PRIV void srd_inst_free(struct srd_decoder_inst *di)
620 {
621  GSList *l;
622  struct srd_pd_output *pdo;
623 
624  srd_dbg("Freeing instance %s", di->inst_id);
625 
626  Py_DecRef(di->py_inst);
627  g_free(di->inst_id);
628  g_free(di->dec_channelmap);
629  g_slist_free(di->next_di);
630  for (l = di->pd_output; l; l = l->next) {
631  pdo = l->data;
632  g_free(pdo->proto_id);
633  g_free(pdo);
634  }
635  g_slist_free(di->pd_output);
636  g_free(di);
637 }
638 
639 /** @private */
640 SRD_PRIV void srd_inst_free_all(struct srd_session *sess, GSList *stack)
641 {
642  GSList *l;
643  struct srd_decoder_inst *di;
644 
645  if (session_is_valid(sess) != SRD_OK) {
646  srd_err("Invalid session.");
647  return;
648  }
649 
650  di = NULL;
651  for (l = stack ? stack : sess->di_list; di == NULL && l != NULL; l = l->next) {
652  di = l->data;
653  if (di->next_di)
654  srd_inst_free_all(sess, di->next_di);
655  srd_inst_free(di);
656  }
657  if (!stack) {
658  g_slist_free(sess->di_list);
659  sess->di_list = NULL;
660  }
661 }
662 
663 /** @} */
664 
uint8_t * channel_samples
GSList * opt_channels
List of optional channels for this decoder.
The public libsigrokdecode header file to be used by frontends.
PyObject * py_dec
sigrokdecode.Decoder class.
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:306
Structure which contains information about one protocol decoder channel.
#define SRD_PRIV
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
PyObject * sample
uint64_t inbuflen
char * name
The (short) decoder name.
int order
The index of the channel, i.e.
char * id
The ID of the channel.
unsigned int itercnt
#define SRD_API
PyObject_HEAD struct srd_decoder_inst * di
Python C API error.
int srd_inst_channel_set_all(struct srd_decoder_inst *di, GHashTable *new_channels, int unit_size)
Set all channels in a decoder instance.
Definition: instance.c:197
No error.
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:401
Function argument error.
Generic/unspecified error.
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:442
uint8_t * inbuf
GSList * options
List of decoder options.
struct srd_decoder * decoder
struct srd_decoder * srd_decoder_get_by_id(const char *id)
Get the decoder with the specified ID.
Definition: decoder.c:89
Malloc/calloc/realloc error.
uint64_t start_samplenum
GSList * channels
List of channels required by this decoder.
struct srd_session * sess