libsigrokdecode  0.5.0
sigrok protocol decoding library
session.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) 2013 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 <inttypes.h>
25 #include <glib.h>
26 
27 /**
28  * @file
29  *
30  * Session handling.
31  */
32 
33 /**
34  * @defgroup grp_session Session handling
35  *
36  * Starting and handling decoding sessions.
37  *
38  * @{
39  */
40 
41 /** @cond PRIVATE */
42 
43 SRD_PRIV GSList *sessions = NULL;
44 SRD_PRIV int max_session_id = -1;
45 
46 /** @endcond */
47 
48 /** @private */
49 SRD_PRIV int session_is_valid(struct srd_session *sess)
50 {
51 
52  if (!sess || sess->session_id < 1)
53  return SRD_ERR;
54 
55  return SRD_OK;
56 }
57 
58 /**
59  * Create a decoding session.
60  *
61  * A session holds all decoder instances, their stack relationships and
62  * output callbacks.
63  *
64  * @param sess A pointer which will hold a pointer to a newly
65  * initialized session on return.
66  *
67  * @return SRD_OK upon success, a (negative) error code otherwise.
68  *
69  * @since 0.3.0
70  */
71 SRD_API int srd_session_new(struct srd_session **sess)
72 {
73 
74  if (!sess) {
75  srd_err("Invalid session pointer.");
76  return SRD_ERR_ARG;
77  }
78 
79  *sess = g_malloc(sizeof(struct srd_session));
80  (*sess)->session_id = ++max_session_id;
81  (*sess)->di_list = (*sess)->callbacks = NULL;
82 
83  /* Keep a list of all sessions, so we can clean up as needed. */
84  sessions = g_slist_append(sessions, *sess);
85 
86  srd_dbg("Created session %d.", (*sess)->session_id);
87 
88  return SRD_OK;
89 }
90 
91 /**
92  * Start a decoding session.
93  *
94  * Decoders, instances and stack must have been prepared beforehand,
95  * and all SRD_CONF parameters set.
96  *
97  * @param sess The session to start.
98  *
99  * @return SRD_OK upon success, a (negative) error code otherwise.
100  *
101  * @since 0.3.0
102  */
103 SRD_API int srd_session_start(struct srd_session *sess)
104 {
105  GSList *d;
106  struct srd_decoder_inst *di;
107  int ret;
108 
109  if (session_is_valid(sess) != SRD_OK) {
110  srd_err("Invalid session pointer.");
111  return SRD_ERR;
112  }
113 
114  srd_dbg("Calling start() on all instances in session %d.", sess->session_id);
115 
116  /* Run the start() method on all decoders receiving frontend data. */
117  ret = SRD_OK;
118  for (d = sess->di_list; d; d = d->next) {
119  di = d->data;
120  if ((ret = srd_inst_start(di)) != SRD_OK)
121  break;
122  }
123 
124  return ret;
125 }
126 
127 static int srd_inst_send_meta(struct srd_decoder_inst *di, int key,
128  GVariant *data)
129 {
130  PyObject *py_ret;
131  GSList *l;
132  struct srd_decoder_inst *next_di;
133  int ret;
134 
135  if (key != SRD_CONF_SAMPLERATE)
136  /* This is the only key we pass on to the decoder for now. */
137  return SRD_OK;
138 
139  if (PyObject_HasAttrString(di->py_inst, "metadata")) {
140  py_ret = PyObject_CallMethod(di->py_inst, "metadata", "lK",
141  (long)SRD_CONF_SAMPLERATE,
142  (unsigned long long)g_variant_get_uint64(data));
143  Py_XDECREF(py_ret);
144  }
145 
146  /* Push metadata to all the PDs stacked on top of this one. */
147  for (l = di->next_di; l; l = l->next) {
148  next_di = l->data;
149  if ((ret = srd_inst_send_meta(next_di, key, data)) != SRD_OK)
150  return ret;
151  }
152 
153  return SRD_OK;
154 }
155 
156 /**
157  * Set a metadata configuration key in a session.
158  *
159  * @param sess The session to configure.
160  * @param key The configuration key (SRD_CONF_*).
161  * @param data The new value for the key, as a GVariant with GVariantType
162  * appropriate to that key. A floating reference can be passed
163  * in; its refcount will be sunk and unreferenced after use.
164  *
165  * @return SRD_OK upon success, a (negative) error code otherwise.
166  *
167  * @since 0.3.0
168  */
169 SRD_API int srd_session_metadata_set(struct srd_session *sess, int key,
170  GVariant *data)
171 {
172  GSList *l;
173  int ret;
174 
175  if (session_is_valid(sess) != SRD_OK) {
176  srd_err("Invalid session.");
177  return SRD_ERR_ARG;
178  }
179 
180  if (!key) {
181  srd_err("Invalid key.");
182  return SRD_ERR_ARG;
183  }
184 
185  if (!data) {
186  srd_err("Invalid value.");
187  return SRD_ERR_ARG;
188  }
189 
190  /* Hardcoded to samplerate/uint64 for now. */
191 
192  if (key != SRD_CONF_SAMPLERATE) {
193  srd_err("Unknown config key %d.", key);
194  return SRD_ERR_ARG;
195  }
196  if (!g_variant_is_of_type(data, G_VARIANT_TYPE_UINT64)) {
197  srd_err("Invalid value type: expected uint64, got %s",
198  g_variant_get_type_string(data));
199  return SRD_ERR_ARG;
200  }
201 
202  srd_dbg("Setting session %d samplerate to %"PRIu64".",
203  sess->session_id, g_variant_get_uint64(data));
204 
205  ret = SRD_OK;
206  for (l = sess->di_list; l; l = l->next) {
207  if ((ret = srd_inst_send_meta(l->data, key, data)) != SRD_OK)
208  break;
209  }
210 
211  g_variant_unref(data);
212 
213  return ret;
214 }
215 
216 /**
217  * Send a chunk of logic sample data to a running decoder session.
218  *
219  * If no channel map has been set up, the logic samples must be arranged
220  * in channel order, in the least amount of space possible. The default
221  * channel set consists of all required channels + all optional channels.
222  *
223  * The size of a sample in inbuf is 'unitsize' bytes. If no channel map
224  * has been configured, it is the minimum number of bytes needed to store
225  * the default channels.
226  *
227  * The calls to this function must provide the samples that shall be
228  * used by the protocol decoder
229  * - in the correct order ([...]5, 6, 4, 7, 8[...] is a bug),
230  * - starting from sample zero (2, 3, 4, 5, 6[...] is a bug),
231  * - consecutively, with no gaps (0, 1, 2, 4, 5[...] is a bug).
232  *
233  * The start- and end-sample numbers are absolute sample numbers (relative
234  * to the start of the whole capture/file/stream), i.e. they are not relative
235  * sample numbers within the chunk specified by 'inbuf' and 'inbuflen'.
236  *
237  * Correct example (4096 samples total, 4 chunks @ 1024 samples each):
238  * srd_session_send(s, 0, 1023, inbuf, 1024, 1);
239  * srd_session_send(s, 1024, 2047, inbuf, 1024, 1);
240  * srd_session_send(s, 2048, 3071, inbuf, 1024, 1);
241  * srd_session_send(s, 3072, 4095, inbuf, 1024, 1);
242  *
243  * The chunk size ('inbuflen') can be arbitrary and can differ between calls.
244  *
245  * Correct example (4096 samples total, 7 chunks @ various samples each):
246  * srd_session_send(s, 0, 1023, inbuf, 1024, 1);
247  * srd_session_send(s, 1024, 1123, inbuf, 100, 1);
248  * srd_session_send(s, 1124, 1423, inbuf, 300, 1);
249  * srd_session_send(s, 1424, 1642, inbuf, 219, 1);
250  * srd_session_send(s, 1643, 2047, inbuf, 405, 1);
251  * srd_session_send(s, 2048, 3071, inbuf, 1024, 1);
252  * srd_session_send(s, 3072, 4095, inbuf, 1024, 1);
253  *
254  * INCORRECT example (4096 samples total, 4 chunks @ 1024 samples each, but
255  * the start- and end-samplenumbers are not absolute):
256  * srd_session_send(s, 0, 1023, inbuf, 1024, 1);
257  * srd_session_send(s, 0, 1023, inbuf, 1024, 1);
258  * srd_session_send(s, 0, 1023, inbuf, 1024, 1);
259  * srd_session_send(s, 0, 1023, inbuf, 1024, 1);
260  *
261  * @param sess The session to use. Must not be NULL.
262  * @param abs_start_samplenum The absolute starting sample number for the
263  * buffer's sample set, relative to the start of capture.
264  * @param abs_end_samplenum The absolute ending sample number for the
265  * buffer's sample set, relative to the start of capture.
266  * @param inbuf Pointer to sample data. Must not be NULL.
267  * @param inbuflen Length in bytes of the buffer. Must be > 0.
268  * @param unitsize The number of bytes per sample. Must be > 0.
269  *
270  * @return SRD_OK upon success, a (negative) error code otherwise.
271  *
272  * @since 0.4.0
273  */
274 SRD_API int srd_session_send(struct srd_session *sess,
275  uint64_t abs_start_samplenum, uint64_t abs_end_samplenum,
276  const uint8_t *inbuf, uint64_t inbuflen, uint64_t unitsize)
277 {
278  GSList *d;
279  int ret;
280 
281  if (session_is_valid(sess) != SRD_OK) {
282  srd_err("Invalid session.");
283  return SRD_ERR_ARG;
284  }
285 
286  for (d = sess->di_list; d; d = d->next) {
287  if ((ret = srd_inst_decode(d->data, abs_start_samplenum,
288  abs_end_samplenum, inbuf, inbuflen, unitsize)) != SRD_OK)
289  return ret;
290  }
291 
292  return SRD_OK;
293 }
294 
295 /**
296  * Destroy a decoding session.
297  *
298  * All decoder instances and output callbacks are properly released.
299  *
300  * @param sess The session to be destroyed.
301  *
302  * @return SRD_OK upon success, a (negative) error code otherwise.
303  *
304  * @since 0.3.0
305  */
306 SRD_API int srd_session_destroy(struct srd_session *sess)
307 {
308  int session_id;
309 
310  if (!sess) {
311  srd_err("Invalid session.");
312  return SRD_ERR_ARG;
313  }
314 
315  session_id = sess->session_id;
316  if (sess->di_list)
317  srd_inst_free_all(sess);
318  if (sess->callbacks)
319  g_slist_free_full(sess->callbacks, g_free);
320  sessions = g_slist_remove(sessions, sess);
321  g_free(sess);
322 
323  srd_dbg("Destroyed session %d.", session_id);
324 
325  return SRD_OK;
326 }
327 
328 /**
329  * Register/add a decoder output callback function.
330  *
331  * The function will be called when a protocol decoder sends output back
332  * to the PD controller (except for Python objects, which only go up the
333  * stack).
334  *
335  * @param sess The output session in which to register the callback.
336  * @param output_type The output type this callback will receive. Only one
337  * callback per output type can be registered.
338  * @param cb The function to call. Must not be NULL.
339  * @param cb_data Private data for the callback function. Can be NULL.
340  *
341  * @since 0.3.0
342  */
343 SRD_API int srd_pd_output_callback_add(struct srd_session *sess,
344  int output_type, srd_pd_output_callback cb, void *cb_data)
345 {
346  struct srd_pd_callback *pd_cb;
347 
348  if (session_is_valid(sess) != SRD_OK) {
349  srd_err("Invalid session.");
350  return SRD_ERR_ARG;
351  }
352 
353  srd_dbg("Registering new callback for output type %d.", output_type);
354 
355  pd_cb = g_malloc(sizeof(struct srd_pd_callback));
356  pd_cb->output_type = output_type;
357  pd_cb->cb = cb;
358  pd_cb->cb_data = cb_data;
359  sess->callbacks = g_slist_append(sess->callbacks, pd_cb);
360 
361  return SRD_OK;
362 }
363 
364 /** @private */
365 SRD_PRIV struct srd_pd_callback *srd_pd_output_callback_find(
366  struct srd_session *sess, int output_type)
367 {
368  GSList *l;
369  struct srd_pd_callback *tmp, *pd_cb;
370 
371  if (session_is_valid(sess) != SRD_OK) {
372  srd_err("Invalid session.");
373  return NULL;
374  }
375 
376  pd_cb = NULL;
377  for (l = sess->callbacks; l; l = l->next) {
378  tmp = l->data;
379  if (tmp->output_type == output_type) {
380  pd_cb = tmp;
381  break;
382  }
383  }
384 
385  return pd_cb;
386 }
387 
388 /** @} */
No error.
Function argument error.
int srd_session_send(struct srd_session *sess, uint64_t abs_start_samplenum, uint64_t abs_end_samplenum, const uint8_t *inbuf, uint64_t inbuflen, uint64_t unitsize)
Send a chunk of logic sample data to a running decoder session.
Definition: session.c:274
uint64_t abs_end_samplenum
Absolute end sample number.
struct srd_session * sess
srd_pd_output_callback cb
int srd_session_start(struct srd_session *sess)
Start a decoding session.
Definition: session.c:103
uint64_t inbuflen
Length (in bytes) of the input sample buffer.
#define SRD_API
int srd_pd_output_callback_add(struct srd_session *sess, int output_type, srd_pd_output_callback cb, void *cb_data)
Register/add a decoder output callback function.
Definition: session.c:343
const uint8_t * inbuf
Pointer to the buffer/chunk of input samples.
Generic/unspecified error.
int srd_session_destroy(struct srd_session *sess)
Destroy a decoding session.
Definition: session.c:306
int srd_session_new(struct srd_session **sess)
Create a decoding session.
Definition: session.c:71
int srd_session_metadata_set(struct srd_session *sess, int key, GVariant *data)
Set a metadata configuration key in a session.
Definition: session.c:169
The public libsigrokdecode header file to be used by frontends.
uint64_t abs_start_samplenum
Absolute start sample number.
#define SRD_PRIV
void(* srd_pd_output_callback)(struct srd_proto_data *pdata, void *cb_data)