lib: bt_object_{get,put}_ref(): accept a `const` parameter
[babeltrace.git] / lib / plugin / plugin.c
1 /*
2 * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
4 *
5 * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25
26 #define BT_LOG_TAG "PLUGIN"
27 #include <babeltrace/lib-logging-internal.h>
28
29 #include <babeltrace/babeltrace-internal.h>
30 #include <babeltrace/compiler-internal.h>
31 #include <babeltrace/object.h>
32 #include <babeltrace/common-internal.h>
33 #include <babeltrace/plugin/plugin-internal.h>
34 #include <babeltrace/plugin/plugin-so-internal.h>
35 #include <babeltrace/graph/component-class.h>
36 #include <babeltrace/graph/component-class-internal.h>
37 #include <babeltrace/types.h>
38 #include <babeltrace/assert-internal.h>
39 #include <babeltrace/assert-pre-internal.h>
40 #include <glib.h>
41 #include <unistd.h>
42 #include <stdlib.h>
43 #include <stdint.h>
44 #include <inttypes.h>
45 #include <sys/stat.h>
46 #include <ftw.h>
47 #include <pthread.h>
48
49 #define PYTHON_PLUGIN_PROVIDER_FILENAME "libbabeltrace-python-plugin-provider." G_MODULE_SUFFIX
50 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME bt_plugin_python_create_all_from_file
51 #define PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR TOSTRING(PYTHON_PLUGIN_PROVIDER_SYM_NAME)
52
53 #define APPEND_ALL_FROM_DIR_NFDOPEN_MAX 8
54
55 #ifdef BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT
56 #include <babeltrace/plugin/python-plugin-provider-internal.h>
57
58 static
59 struct bt_plugin_set *(*bt_plugin_python_create_all_from_file_sym)(const char *path) =
60 bt_plugin_python_create_all_from_file;
61
62 static
63 void init_python_plugin_provider(void) {}
64 #else /* BT_BUILT_IN_PYTHON_PLUGIN_SUPPORT */
65 static GModule *python_plugin_provider_module;
66 static
67 struct bt_plugin_set *(*bt_plugin_python_create_all_from_file_sym)(const char *path);
68
69 static
70 void init_python_plugin_provider(void) {
71 if (bt_plugin_python_create_all_from_file_sym != NULL) {
72 return;
73 }
74
75 BT_LOGD_STR("Loading Python plugin provider module.");
76 python_plugin_provider_module =
77 g_module_open(PYTHON_PLUGIN_PROVIDER_FILENAME, 0);
78 if (!python_plugin_provider_module) {
79 BT_LOGI("Cannot open `%s`: %s: continuing without Python plugin support.",
80 PYTHON_PLUGIN_PROVIDER_FILENAME, g_module_error());
81 return;
82 }
83
84 if (!g_module_symbol(python_plugin_provider_module,
85 PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR,
86 (gpointer) &bt_plugin_python_create_all_from_file_sym)) {
87 BT_LOGI("Cannot find the Python plugin provider loading symbol: continuing without Python plugin support: "
88 "file=\"%s\", symbol=\"%s\"",
89 PYTHON_PLUGIN_PROVIDER_FILENAME,
90 PYTHON_PLUGIN_PROVIDER_SYM_NAME_STR);
91 return;
92 }
93
94 BT_LOGI("Loaded Python plugin provider module: addr=%p",
95 python_plugin_provider_module);
96 }
97
98 __attribute__((destructor)) static
99 void fini_python_plugin_provider(void) {
100 if (python_plugin_provider_module) {
101 BT_LOGD("Unloading Python plugin provider module.");
102
103 if (!g_module_close(python_plugin_provider_module)) {
104 BT_LOGE("Failed to close the Python plugin provider module: %s.",
105 g_module_error());
106 }
107
108 python_plugin_provider_module = NULL;
109 }
110 }
111 #endif
112
113 uint64_t bt_plugin_set_get_plugin_count(struct bt_plugin_set *plugin_set)
114 {
115 BT_ASSERT_PRE_NON_NULL(plugin_set, "Plugin set");
116 return (uint64_t) plugin_set->plugins->len;
117 }
118
119 struct bt_plugin *bt_plugin_set_borrow_plugin_by_index(
120 struct bt_plugin_set *plugin_set,
121 uint64_t index)
122 {
123 BT_ASSERT_PRE_NON_NULL(plugin_set, "Plugin set");
124 BT_ASSERT_PRE_VALID_INDEX(index, plugin_set->plugins->len);
125 return g_ptr_array_index(plugin_set->plugins, index);
126 }
127
128 struct bt_plugin_set *bt_plugin_create_all_from_static(void)
129 {
130 /* bt_plugin_so_create_all_from_static() logs errors */
131 return bt_plugin_so_create_all_from_static();
132 }
133
134 struct bt_plugin_set *bt_plugin_create_all_from_file(const char *path)
135 {
136 struct bt_plugin_set *plugin_set = NULL;
137
138 BT_ASSERT_PRE_NON_NULL(path, "Path");
139 BT_LOGD("Creating plugins from file: path=\"%s\"", path);
140
141 /* Try shared object plugins */
142 plugin_set = bt_plugin_so_create_all_from_file(path);
143 if (plugin_set) {
144 goto end;
145 }
146
147 /* Try Python plugins if support is available */
148 init_python_plugin_provider();
149 if (bt_plugin_python_create_all_from_file_sym) {
150 plugin_set = bt_plugin_python_create_all_from_file_sym(path);
151 if (plugin_set) {
152 goto end;
153 }
154 }
155
156 end:
157 if (plugin_set) {
158 BT_LOGD("Created %u plugins from file: "
159 "path=\"%s\", count=%u, plugin-set-addr=%p",
160 plugin_set->plugins->len, path,
161 plugin_set->plugins->len, plugin_set);
162 } else {
163 BT_LOGD("Found no plugins in file: path=\"%s\"", path);
164 }
165
166 return plugin_set;
167 }
168
169 static void destroy_gstring(void *data)
170 {
171 g_string_free(data, TRUE);
172 }
173
174 struct bt_plugin *bt_plugin_find(const char *plugin_name)
175 {
176 const char *system_plugin_dir;
177 char *home_plugin_dir = NULL;
178 const char *envvar;
179 struct bt_plugin *plugin = NULL;
180 struct bt_plugin_set *plugin_set = NULL;
181 GPtrArray *dirs = NULL;
182 int ret;
183 size_t i, j;
184
185 BT_ASSERT_PRE_NON_NULL(plugin_name, "Name");
186 BT_LOGD("Finding named plugin in standard directories and built-in plugins: "
187 "name=\"%s\"", plugin_name);
188 dirs = g_ptr_array_new_with_free_func((GDestroyNotify) destroy_gstring);
189 if (!dirs) {
190 BT_LOGE_STR("Failed to allocate a GPtrArray.");
191 goto end;
192 }
193
194 /*
195 * Search order is:
196 *
197 * 1. BABELTRACE_PLUGIN_PATH environment variable
198 * (colon-separated list of directories)
199 * 2. ~/.local/lib/babeltrace/plugins
200 * 3. Default system directory for Babeltrace plugins, usually
201 * /usr/lib/babeltrace/plugins or
202 * /usr/local/lib/babeltrace/plugins if installed
203 * locally
204 * 4. Built-in plugins (static)
205 *
206 * Directories are searched non-recursively.
207 */
208 envvar = getenv("BABELTRACE_PLUGIN_PATH");
209 if (envvar) {
210 ret = bt_common_append_plugin_path_dirs(envvar, dirs);
211 if (ret) {
212 BT_LOGE_STR("Failed to append plugin path to array of directories.");
213 goto end;
214 }
215 }
216
217 home_plugin_dir = bt_common_get_home_plugin_path();
218 if (home_plugin_dir) {
219 GString *home_plugin_dir_str =
220 g_string_new(home_plugin_dir);
221
222 if (!home_plugin_dir_str) {
223 BT_LOGE_STR("Failed to allocate a GString.");
224 goto end;
225 }
226
227 g_ptr_array_add(dirs, home_plugin_dir_str);
228 }
229
230 system_plugin_dir = bt_common_get_system_plugin_path();
231 if (system_plugin_dir) {
232 GString *system_plugin_dir_str =
233 g_string_new(system_plugin_dir);
234
235 if (!system_plugin_dir_str) {
236 BT_LOGE_STR("Failed to allocate a GString.");
237 goto end;
238 }
239
240 g_ptr_array_add(dirs, system_plugin_dir_str);
241 }
242
243 for (i = 0; i < dirs->len; i++) {
244 GString *dir = g_ptr_array_index(dirs, i);
245
246 BT_OBJECT_PUT_REF_AND_RESET(plugin_set);
247
248 /*
249 * Skip this if the directory does not exist because
250 * bt_plugin_create_all_from_dir() would log a warning.
251 */
252 if (!g_file_test(dir->str, G_FILE_TEST_IS_DIR)) {
253 BT_LOGV("Skipping nonexistent directory path: "
254 "path=\"%s\"", dir->str);
255 continue;
256 }
257
258 /* bt_plugin_create_all_from_dir() logs details/errors */
259 plugin_set = bt_plugin_create_all_from_dir(dir->str, BT_FALSE);
260 if (!plugin_set) {
261 BT_LOGD("No plugins found in directory: path=\"%s\"",
262 dir->str);
263 continue;
264 }
265
266 for (j = 0; j < plugin_set->plugins->len; j++) {
267 struct bt_plugin *candidate_plugin =
268 g_ptr_array_index(plugin_set->plugins, j);
269
270 if (strcmp(bt_plugin_get_name(candidate_plugin),
271 plugin_name) == 0) {
272 BT_LOGD("Plugin found in directory: name=\"%s\", path=\"%s\"",
273 plugin_name, dir->str);
274 plugin = candidate_plugin;
275 bt_object_get_no_null_check(plugin);
276 goto end;
277 }
278 }
279
280 BT_LOGD("Plugin not found in directory: name=\"%s\", path=\"%s\"",
281 plugin_name, dir->str);
282 }
283
284 bt_object_put_ref(plugin_set);
285 plugin_set = bt_plugin_create_all_from_static();
286 if (plugin_set) {
287 for (j = 0; j < plugin_set->plugins->len; j++) {
288 struct bt_plugin *candidate_plugin =
289 g_ptr_array_index(plugin_set->plugins, j);
290
291 if (strcmp(bt_plugin_get_name(candidate_plugin),
292 plugin_name) == 0) {
293 BT_LOGD("Plugin found in built-in plugins: "
294 "name=\"%s\"", plugin_name);
295 plugin = candidate_plugin;
296 bt_object_get_no_null_check(plugin);
297 goto end;
298 }
299 }
300 }
301
302 end:
303 free(home_plugin_dir);
304 bt_object_put_ref(plugin_set);
305
306 if (dirs) {
307 g_ptr_array_free(dirs, TRUE);
308 }
309
310 if (plugin) {
311 BT_LIB_LOGD("Found plugin in standard directories and built-in plugins: "
312 "%!+l", plugin);
313 } else {
314 BT_LOGD("No plugin found in standard directories and built-in plugins: "
315 "name=\"%s\"", plugin_name);
316 }
317
318 return plugin;
319 }
320
321 static struct {
322 pthread_mutex_t lock;
323 struct bt_plugin_set *plugin_set;
324 bool recurse;
325 } append_all_from_dir_info = {
326 .lock = PTHREAD_MUTEX_INITIALIZER
327 };
328
329 static
330 int nftw_append_all_from_dir(const char *file, const struct stat *sb, int flag,
331 struct FTW *s)
332 {
333 int ret = 0;
334 const char *name = file + s->base;
335
336 /* Check for recursion */
337 if (!append_all_from_dir_info.recurse && s->level > 1) {
338 goto end;
339 }
340
341 switch (flag) {
342 case FTW_F:
343 {
344 struct bt_plugin_set *plugins_from_file;
345
346 if (name[0] == '.') {
347 /* Skip hidden files */
348 BT_LOGV("Skipping hidden file: path=\"%s\"", file);
349 goto end;
350 }
351
352 plugins_from_file = bt_plugin_create_all_from_file(file);
353
354 if (plugins_from_file) {
355 size_t j;
356
357 for (j = 0; j < plugins_from_file->plugins->len; j++) {
358 struct bt_plugin *plugin =
359 g_ptr_array_index(plugins_from_file->plugins, j);
360
361 BT_LIB_LOGD("Adding plugin to plugin set: "
362 "plugin-path=\"%s\", %![plugin-]+l",
363 file, plugin);
364 bt_plugin_set_add_plugin(append_all_from_dir_info.plugin_set, plugin);
365 }
366
367 bt_object_put_ref(plugins_from_file);
368 }
369 break;
370 }
371 case FTW_DNR:
372 /* Continue to next file / directory. */
373 BT_LOGW("Cannot enter directory: continuing: path=\"%s\"", file);
374 break;
375 case FTW_NS:
376 /* Continue to next file / directory. */
377 BT_LOGD("Cannot get file information: continuing: path=\"%s\"", file);
378 break;
379 }
380
381 end:
382 return ret;
383 }
384
385 static
386 enum bt_plugin_status bt_plugin_create_append_all_from_dir(
387 struct bt_plugin_set *plugin_set, const char *path,
388 bt_bool recurse)
389 {
390 int nftw_flags = FTW_PHYS;
391 enum bt_plugin_status ret = BT_PLUGIN_STATUS_OK;
392
393 BT_ASSERT(plugin_set);
394 BT_ASSERT(path);
395 BT_ASSERT(strlen(path) < PATH_MAX);
396 pthread_mutex_lock(&append_all_from_dir_info.lock);
397 append_all_from_dir_info.plugin_set = plugin_set;
398 append_all_from_dir_info.recurse = recurse;
399 ret = nftw(path, nftw_append_all_from_dir,
400 APPEND_ALL_FROM_DIR_NFDOPEN_MAX, nftw_flags);
401 pthread_mutex_unlock(&append_all_from_dir_info.lock);
402 if (ret != 0) {
403 BT_LOGW_ERRNO("Cannot open directory", ": path=\"%s\"", path);
404 ret = BT_PLUGIN_STATUS_ERROR;
405 }
406
407 return ret;
408 }
409
410 struct bt_plugin_set *bt_plugin_create_all_from_dir(const char *path,
411 bt_bool recurse)
412 {
413 struct bt_plugin_set *plugin_set;
414 enum bt_plugin_status status;
415
416 BT_LOGD("Creating all plugins in directory: path=\"%s\", recurse=%d",
417 path, recurse);
418 plugin_set = bt_plugin_set_create();
419 if (!plugin_set) {
420 BT_LOGE_STR("Cannot create empty plugin set.");
421 goto error;
422 }
423
424 /* Append found plugins to array */
425 status = bt_plugin_create_append_all_from_dir(plugin_set, path,
426 recurse);
427 if (status < 0) {
428 BT_LOGW("Cannot append plugins found in directory: "
429 "path=\"%s\", status=%s",
430 path, bt_plugin_status_string(status));
431 goto error;
432 }
433
434 BT_LOGD("Created %u plugins from directory: count=%u, path=\"%s\"",
435 plugin_set->plugins->len, plugin_set->plugins->len, path);
436 goto end;
437
438 error:
439 BT_OBJECT_PUT_REF_AND_RESET(plugin_set);
440
441 end:
442 return plugin_set;
443 }
444
445 const char *bt_plugin_get_name(struct bt_plugin *plugin)
446 {
447 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
448 return plugin->info.name_set ? plugin->info.name->str : NULL;
449 }
450
451 const char *bt_plugin_get_author(struct bt_plugin *plugin)
452 {
453 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
454 return plugin->info.author_set ? plugin->info.author->str : NULL;
455 }
456
457 const char *bt_plugin_get_license(struct bt_plugin *plugin)
458 {
459 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
460 return plugin->info.license_set ? plugin->info.license->str : NULL;
461 }
462
463 const char *bt_plugin_get_path(struct bt_plugin *plugin)
464 {
465 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
466 return plugin->info.path_set ? plugin->info.path->str : NULL;
467 }
468
469 const char *bt_plugin_get_description(struct bt_plugin *plugin)
470 {
471 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
472 return plugin->info.description_set ?
473 plugin->info.description->str : NULL;
474 }
475
476 enum bt_property_availability bt_plugin_get_version(struct bt_plugin *plugin,
477 unsigned int *major, unsigned int *minor, unsigned int *patch,
478 const char **extra)
479 {
480 enum bt_property_availability avail =
481 BT_PROPERTY_AVAILABILITY_AVAILABLE;
482
483 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
484
485 if (!plugin->info.version_set) {
486 BT_LIB_LOGV("Plugin's version is not set: %!+l", plugin);
487 avail = BT_PROPERTY_AVAILABILITY_NOT_AVAILABLE;
488 goto end;
489 }
490
491 if (major) {
492 *major = plugin->info.version.major;
493 }
494
495 if (minor) {
496 *minor = plugin->info.version.minor;
497 }
498
499 if (patch) {
500 *patch = plugin->info.version.patch;
501 }
502
503 if (extra) {
504 *extra = plugin->info.version.extra->str;
505 }
506
507 end:
508 return avail;
509 }
510
511 uint64_t bt_plugin_get_source_component_class_count(struct bt_plugin *plugin)
512 {
513 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
514 return (uint64_t) plugin->src_comp_classes->len;
515 }
516
517 uint64_t bt_plugin_get_filter_component_class_count(struct bt_plugin *plugin)
518 {
519 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
520 return (uint64_t) plugin->flt_comp_classes->len;
521 }
522
523 uint64_t bt_plugin_get_sink_component_class_count(struct bt_plugin *plugin)
524 {
525 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
526 return (uint64_t) plugin->sink_comp_classes->len;
527 }
528
529 static inline
530 struct bt_component_class *borrow_component_class_by_index(
531 struct bt_plugin *plugin, GPtrArray *comp_classes,
532 uint64_t index)
533 {
534 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
535 BT_ASSERT_PRE_VALID_INDEX(index, comp_classes->len);
536 return g_ptr_array_index(comp_classes, index);
537 }
538
539
540 struct bt_component_class_source *
541 bt_plugin_borrow_source_component_class_by_index(
542 struct bt_plugin *plugin, uint64_t index)
543 {
544 return (void *) borrow_component_class_by_index(plugin,
545 plugin->src_comp_classes, index);
546 }
547
548 struct bt_component_class_filter *
549 bt_plugin_borrow_filter_component_class_by_index(
550 struct bt_plugin *plugin, uint64_t index)
551 {
552 return (void *) borrow_component_class_by_index(plugin,
553 plugin->flt_comp_classes, index);
554 }
555
556 struct bt_component_class_sink *
557 bt_plugin_borrow_sink_component_class_by_index(
558 struct bt_plugin *plugin, uint64_t index)
559 {
560 return (void *) borrow_component_class_by_index(plugin,
561 plugin->sink_comp_classes, index);
562 }
563
564 static inline
565 struct bt_component_class *borrow_component_class_by_name(
566 struct bt_plugin *plugin, GPtrArray *comp_classes,
567 const char *name)
568 {
569 struct bt_component_class *comp_class = NULL;
570 size_t i;
571
572 BT_ASSERT_PRE_NON_NULL(plugin, "Plugin");
573 BT_ASSERT_PRE_NON_NULL(name, "Name");
574
575 for (i = 0; i < comp_classes->len; i++) {
576 struct bt_component_class *comp_class_candidate =
577 g_ptr_array_index(comp_classes, i);
578 const char *comp_class_cand_name =
579 bt_component_class_get_name(comp_class_candidate);
580
581 BT_ASSERT(comp_class_cand_name);
582
583 if (strcmp(name, comp_class_cand_name) == 0) {
584 comp_class = comp_class_candidate;
585 break;
586 }
587 }
588
589 return comp_class;
590 }
591
592 struct bt_component_class_source *
593 bt_plugin_borrow_source_component_class_by_name(struct bt_plugin *plugin,
594 const char *name)
595 {
596 return (void *) borrow_component_class_by_name(plugin,
597 plugin->src_comp_classes, name);
598 }
599
600 struct bt_component_class_filter *
601 bt_plugin_borrow_filter_component_class_by_name(struct bt_plugin *plugin,
602 const char *name)
603 {
604 return (void *) borrow_component_class_by_name(plugin,
605 plugin->flt_comp_classes, name);
606 }
607
608 struct bt_component_class_sink *
609 bt_plugin_borrow_sink_component_class_by_name(struct bt_plugin *plugin,
610 const char *name)
611 {
612 return (void *) borrow_component_class_by_name(plugin,
613 plugin->sink_comp_classes, name);
614 }
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