]> sigrok.org Git - libsigrokdecode.git/blame_incremental - decode.c
libsigrokdecode: Allow frontend to configure decoder probes.
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1/*
2 * This file is part of the sigrok project.
3 *
4 * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "config.h"
22#include <sigrokdecode.h> /* First, so we avoid a _POSIX_C_SOURCE warning. */
23#include <stdio.h>
24#include <string.h>
25#include <dirent.h>
26
27/* Re-define some string functions for Python >= 3.0. */
28#if PY_VERSION_HEX >= 0x03000000
29#define PyString_AsString PyBytes_AsString
30#define PyString_FromString PyBytes_FromString
31#define PyString_Check PyBytes_Check
32#endif
33
34/* The list of protocol decoders. */
35static GSList *list_pds = NULL;
36
37/*
38 * Here's a quick overview of Python/C API reference counting.
39 *
40 * Check the Python/C API docs for what type of reference a function returns.
41 *
42 * - If it returns a "new reference", you're responsible to Py_XDECREF() it.
43 *
44 * - If it returns a "borrowed reference", you MUST NOT Py_XDECREF() it.
45 *
46 * - If a function "steals" a reference, you no longer are responsible for
47 * Py_XDECREF()ing it (someone else will do it for you at some point).
48 */
49
50static int srd_load_decoder(const char *name, struct srd_decoder **dec);
51
52static int _unitsize = 1;
53
54static PyObject*
55emb_put(PyObject *self, PyObject *args)
56{
57 PyObject *arg;
58
59 (void)self;
60
61 if (!PyArg_ParseTuple(args, "O:put", &arg))
62 return NULL;
63
64 fprintf(stdout, "sigrok.put() called by decoder:\n");
65 PyObject_Print(arg, stdout, Py_PRINT_RAW);
66 puts("");
67
68 Py_RETURN_NONE;
69}
70
71static PyMethodDef EmbMethods[] = {
72 {"put", emb_put, METH_VARARGS,
73 "Accepts a dictionary with the following keys: time, duration, data"},
74 {NULL, NULL, 0, NULL}
75};
76
77/**
78 * Initialize libsigrokdecode.
79 *
80 * @return SRD_OK upon success, a (negative) error code otherwise.
81 */
82int srd_init(void)
83{
84 DIR *dir;
85 struct dirent *dp;
86 char *decodername;
87 struct srd_decoder *dec;
88 int ret;
89
90 /* Py_Initialize() returns void and usually cannot fail. */
91 Py_Initialize();
92
93 Py_InitModule("sigrok", EmbMethods);
94
95 /* Add search directory for the protocol decoders. */
96 /* FIXME: Check error code. */
97 /* FIXME: What happens if this function is called multiple times? */
98 PyRun_SimpleString("import sys;"
99 "sys.path.append(r'" DECODERS_DIR "');");
100
101 if (!(dir = opendir(DECODERS_DIR)))
102 return SRD_ERR_DECODERS_DIR;
103
104 while ((dp = readdir(dir)) != NULL) {
105 if (!g_str_has_suffix(dp->d_name, ".py"))
106 continue;
107
108 /* Decoder name == filename (without .py suffix). */
109 decodername = g_strndup(dp->d_name, strlen(dp->d_name) - 3);
110
111 /* TODO: Error handling. */
112 dec = malloc(sizeof(struct srd_decoder));
113
114 /* Load the decoder. */
115 ret = srd_load_decoder(decodername, &dec);
116 if (!ret)
117 {
118 /* Append it to the list of supported/loaded decoders. */
119 list_pds = g_slist_append(list_pds, dec);
120 }
121 }
122 closedir(dir);
123
124 return SRD_OK;
125}
126
127/**
128 * Returns the list of supported/loaded protocol decoders.
129 *
130 * This is a GSList containing the names of the decoders as strings.
131 *
132 * @return List of decoders, NULL if none are supported or loaded.
133 */
134GSList *srd_list_decoders(void)
135{
136 return list_pds;
137}
138
139/**
140 * Get the decoder with the specified ID.
141 *
142 * @param id The ID string of the decoder to return.
143 * @return The decoder with the specified ID, or NULL if not found.
144 */
145struct srd_decoder *srd_get_decoder_by_id(const char *id)
146{
147 GSList *l;
148 struct srd_decoder *dec;
149
150 for (l = srd_list_decoders(); l; l = l->next) {
151 dec = l->data;
152 if (!strcmp(dec->id, id))
153 return dec;
154 }
155
156 return NULL;
157}
158
159/**
160 * Helper function to handle Python strings.
161 *
162 * TODO: @param entries.
163 *
164 * @return SRD_OK upon success, a (negative) error code otherwise.
165 * The 'outstr' argument points to a malloc()ed string upon success.
166 */
167static int h_str(PyObject *py_res, PyObject *py_mod,
168 const char *key, char **outstr)
169{
170 PyObject *py_str;
171 char *str;
172 int ret;
173
174 py_str = PyObject_GetAttrString(py_res, (char *)key); /* NEWREF */
175 if (!py_str || !PyString_Check(py_str)) {
176 ret = SRD_ERR_PYTHON; /* TODO: More specific error? */
177 goto err_h_decref_mod;
178 }
179
180 /*
181 * PyString_AsString()'s returned string refers to an internal buffer
182 * (not a copy), i.e. the data must not be modified, and the memory
183 * must not be free()'d.
184 */
185 if (!(str = PyString_AsString(py_str))) {
186 ret = SRD_ERR_PYTHON; /* TODO: More specific error? */
187 goto err_h_decref_str;
188 }
189
190 if (!(*outstr = g_strdup(str))) {
191 ret = SRD_ERR_MALLOC;
192 goto err_h_decref_str;
193 }
194
195 Py_XDECREF(py_str);
196
197 return SRD_OK;
198
199err_h_decref_str:
200 Py_XDECREF(py_str);
201err_h_decref_mod:
202 Py_XDECREF(py_mod);
203
204 if (PyErr_Occurred())
205 PyErr_Print(); /* Returns void. */
206
207 return ret;
208}
209
210/**
211 * TODO
212 *
213 * @param name TODO
214 *
215 * @return SRD_OK upon success, a (negative) error code otherwise.
216 */
217static int srd_load_decoder(const char *name,
218 struct srd_decoder **dec)
219{
220 struct srd_decoder *d;
221 PyObject *py_mod, *py_res;
222 int r;
223 fprintf(stdout, "%s: %s\n", __func__, name);
224
225 /* "Import" the Python module. */
226 if (!(py_mod = PyImport_ImportModule(name))) { /* NEWREF */
227 PyErr_Print(); /* Returns void. */
228 return SRD_ERR_PYTHON; /* TODO: More specific error? */
229 }
230
231 /* Get the 'Decoder' class as Python object. */
232 py_res = PyObject_GetAttrString(py_mod, "Decoder"); /* NEWREF */
233 if (!py_res) {
234 if (PyErr_Occurred())
235 PyErr_Print(); /* Returns void. */
236 Py_XDECREF(py_mod);
237 fprintf(stderr, "Decoder class not found in PD module %s\n", name);
238 return SRD_ERR_PYTHON; /* TODO: More specific error? */
239 }
240
241 if (!(d = malloc(sizeof(struct srd_decoder))))
242 return SRD_ERR_MALLOC;
243
244 /* We'll just use the name of the module for the id */
245 d->id = strdup(name);
246
247 if ((r = h_str(py_res, py_mod, "name", &(d->name))) < 0)
248 return r;
249
250 if ((r = h_str(py_res, py_mod, "longname",
251 &(d->longname))) < 0)
252 return r;
253
254 if ((r = h_str(py_res, py_mod, "desc", &(d->desc))) < 0)
255 return r;
256
257 if ((r = h_str(py_res, py_mod, "longdesc",
258 &(d->longdesc))) < 0)
259 return r;
260
261 if ((r = h_str(py_res, py_mod, "author", &(d->author))) < 0)
262 return r;
263
264 if ((r = h_str(py_res, py_mod, "email", &(d->email))) < 0)
265 return r;
266
267 if ((r = h_str(py_res, py_mod, "license", &(d->license))) < 0)
268 return r;
269
270 d->py_mod = py_mod;
271 d->py_decobj = py_res;
272
273 /* TODO: Handle func, inputformats, outputformats. */
274 /* Note: They must at least be set to NULL, will segfault otherwise. */
275 d->func = NULL;
276 d->inputformats = NULL;
277 d->outputformats = NULL;
278
279 *dec = d;
280
281 return SRD_OK;
282}
283
284struct srd_decoder_instance *srd_instance_new(const char *id)
285{
286 struct srd_decoder *dec = srd_get_decoder_by_id(id);
287 if (!dec)
288 return NULL;
289 struct srd_decoder_instance *di = g_malloc(sizeof(*di));
290 PyObject *py_args, *py_value;
291
292 /* Create a Python tuple of size 1. */
293 if (!(py_args = PyTuple_New(0))) { /* NEWREF */
294 if (PyErr_Occurred())
295 PyErr_Print(); /* Returns void. */
296
297 return NULL; /* TODO: More specific error? */
298 }
299
300 py_value = Py_BuildValue("{sssisd}",
301 "driver", "demo",
302 "unitsize", _unitsize, //FIXME: Pass in a unitsize that matches the selected LA
303 "starttime", 129318231823.0 //TODO: Fill with something reasonable.
304 );
305
306 /* Create an instance of the Decoder class */
307 di->py_instance = PyObject_Call(dec->py_decobj, py_args, py_value);
308 if (!di->py_instance) {
309 if (PyErr_Occurred())
310 PyErr_Print(); /* Returns void. */
311 Py_XDECREF(py_args);
312 Py_XDECREF(py_value); /* TODO: Ref. stolen upon error? */
313 return NULL; /* TODO: More specific error? */
314 }
315
316 Py_XDECREF(py_args);
317 Py_XDECREF(py_value);
318
319 return di;
320}
321
322int srd_instance_set_probe(struct srd_decoder_instance *di,
323 const char *probename, int num)
324{
325 PyObject *probedict, *probenum;
326 probedict = PyObject_GetAttrString(di->py_instance, "probes"); /* NEWREF */
327 if (!probedict) {
328 if (PyErr_Occurred())
329 PyErr_Print(); /* Returns void. */
330
331 return SRD_ERR_PYTHON; /* TODO: More specific error? */
332 }
333
334 probenum = PyInt_FromLong(num);
335 PyMapping_SetItemString(probedict, (char*)probename, probenum);
336
337 Py_XDECREF(probenum);
338 Py_XDECREF(probedict);
339 return SRD_OK;
340}
341
342/**
343 * Run the specified decoder function.
344 *
345 * @param dec TODO
346 * @param inbuf TODO
347 * @param inbuflen TODO
348 * @param outbuf TODO
349 * @param outbuflen TODO
350 *
351 * @return SRD_OK upon success, a (negative) error code otherwise.
352 */
353int srd_run_decoder(struct srd_decoder_instance *dec,
354 uint8_t *inbuf, uint64_t inbuflen,
355 uint8_t **outbuf, uint64_t *outbuflen)
356{
357 PyObject *py_instance, *py_value, *py_res;
358 int ret;
359
360 /* FIXME: Don't have a timebase available here. Make one up. */
361 static int _timehack = 0;
362 _timehack += inbuflen;
363
364 /* TODO: Use #defines for the return codes. */
365
366 /* Return an error upon unusable input. */
367 if (dec == NULL)
368 return SRD_ERR_ARGS; /* TODO: More specific error? */
369 if (inbuf == NULL)
370 return SRD_ERR_ARGS; /* TODO: More specific error? */
371 if (inbuflen == 0) /* No point in working on empty buffers. */
372 return SRD_ERR_ARGS; /* TODO: More specific error? */
373 if (outbuf == NULL)
374 return SRD_ERR_ARGS; /* TODO: More specific error? */
375 if (outbuflen == NULL)
376 return SRD_ERR_ARGS; /* TODO: More specific error? */
377
378 /* TODO: Error handling. */
379 py_instance = dec->py_instance;
380 Py_XINCREF(py_instance);
381
382 /* Get the input buffer as Python "string" (byte array). */
383 /* TODO: int vs. uint64_t for 'inbuflen'? */
384
385 py_value = Py_BuildValue("{sisiss#}",
386 "time", _timehack,
387 "duration", 10,
388 "data", inbuf, inbuflen / _unitsize
389 );
390
391 if (!(py_res = PyObject_CallMethod(py_instance, "decode",
392 "O", py_value))) { /* NEWREF */
393 ret = SRD_ERR_PYTHON; /* TODO: More specific error? */
394 goto err_run_decref_args;
395 }
396
397
398 ret = SRD_OK;
399
400 Py_XDECREF(py_res);
401err_run_decref_args:
402 Py_XDECREF(py_value);
403
404 if (PyErr_Occurred())
405 PyErr_Print(); /* Returns void. */
406
407 return ret;
408}
409
410/**
411 * TODO
412 */
413static int srd_unload_decoder(struct srd_decoder *dec)
414{
415 g_free(dec->id);
416 g_free(dec->name);
417 g_free(dec->desc);
418 g_free(dec->func);
419
420 /* TODO: Free everything in inputformats and outputformats. */
421
422 if (dec->inputformats != NULL)
423 g_slist_free(dec->inputformats);
424 if (dec->outputformats != NULL)
425 g_slist_free(dec->outputformats);
426
427 Py_XDECREF(dec->py_decobj);
428 Py_XDECREF(dec->py_mod);
429
430 return SRD_OK;
431}
432
433/**
434 * TODO
435 */
436static int srd_unload_all_decoders(void)
437{
438 GSList *l;
439 struct srd_decoder *dec;
440
441 for (l = srd_list_decoders(); l; l = l->next) {
442 dec = l->data;
443 /* TODO: Error handling. */
444 srd_unload_decoder(dec);
445 }
446
447 return SRD_OK;
448}
449
450/**
451 * Shutdown libsigrokdecode.
452 *
453 * @return SRD_OK upon success, a (negative) error code otherwise.
454 */
455int srd_exit(void)
456{
457 /* Unload/free all decoders, and then the list of decoders itself. */
458 /* TODO: Error handling. */
459 srd_unload_all_decoders();
460 g_slist_free(list_pds);
461
462 /* Py_Finalize() returns void, any finalization errors are ignored. */
463 Py_Finalize();
464
465 return SRD_OK;
466}