src/bindings/python/bt2/bt2/native_bt_component_class.i.h

   1 /*
   2  * The MIT License (MIT)
   3  *
   4  * Copyright (c) 2017 Philippe Proulx <pproulx@efficios.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "logging/comp-logging.h"
  26
  27 /*
  28  * This hash table associates a BT component class object address to a
  29  * user-defined Python class (PyObject *). The keys and values are NOT
  30  * owned by this hash table. The Python class objects are owned by the
  31  * Python module, which should not be unloaded until it is not possible
  32  * to create a user Python component anyway.
  33  *
  34  * This hash table is written to when a user-defined Python component
  35  * class is created by one of the bt_bt2_component_class_*_create()
  36  * functions.
  37  *
  38  * This function is read from when a user calls bt_component_create()
  39  * with a component class pointer created by one of the functions above.
  40  * In this case, the original Python class needs to be found to
  41  * instantiate it and associate the created Python component object with
  42  * a BT component object instance.
  43  */
  44
  45 static GHashTable *bt_cc_ptr_to_py_cls;
  46
  47 static
  48 void bt_bt2_unregister_cc_ptr_to_py_cls(const bt_component_class *comp_cls)
  49 {
  50         gboolean existed;
  51
  52         if (!bt_cc_ptr_to_py_cls) {
  53                 return;
  54         }
  55
  56         existed = g_hash_table_remove(bt_cc_ptr_to_py_cls, comp_cls);
  57         BT_ASSERT(existed);
  58 }
  59
  60 static
  61 void register_cc_ptr_to_py_cls(struct bt_component_class *bt_cc,
  62                 PyObject *py_cls)
  63 {
  64         if (!bt_cc_ptr_to_py_cls) {
  65                 /*
  66                  * Lazy-initializing this GHashTable because GLib
  67                  * might not be initialized yet and it needs to be
  68                  * before we call g_hash_table_new()
  69                  */
  70                 BT_LOGD_STR("Creating native component class to Python component class hash table.");
  71                 bt_cc_ptr_to_py_cls = g_hash_table_new(g_direct_hash, g_direct_equal);
  72                 BT_ASSERT(bt_cc_ptr_to_py_cls);
  73         }
  74
  75         g_hash_table_insert(bt_cc_ptr_to_py_cls, (gpointer) bt_cc,
  76                 (gpointer) py_cls);
  77 }
  78
  79 static
  80 PyObject *lookup_cc_ptr_to_py_cls(const bt_component_class *bt_cc)
  81 {
  82         if (!bt_cc_ptr_to_py_cls) {
  83                 BT_LOGW("Cannot look up Python component class because hash table is NULL: "
  84                         "comp-cls-addr=%p", bt_cc);
  85                 return NULL;
  86         }
  87
  88         return (PyObject *) g_hash_table_lookup(bt_cc_ptr_to_py_cls,
  89                 (gconstpointer) bt_cc);
  90 }
  91
  92 /* Library destructor */
  93
  94 __attribute__((destructor))
  95 static
  96 void native_comp_class_dtor(void) {
  97         /* Destroy component class association hash table */
  98         if (bt_cc_ptr_to_py_cls) {
  99                 BT_LOGD_STR("Destroying native component class to Python component class hash table.");
 100                 g_hash_table_destroy(bt_cc_ptr_to_py_cls);
 101                 bt_cc_ptr_to_py_cls = NULL;
 102         }
 103 }
 104
 105 static inline
 106 int py_exc_to_status(bt_self_component_class *self_component_class,
 107                 bt_self_component *self_component,
 108                 bt_self_message_iterator *self_message_iterator,
 109                 const char *module_name, int active_log_level)
 110 {
 111         int status = __BT_FUNC_STATUS_OK;
 112         PyObject *exc = PyErr_Occurred();
 113
 114         if (!exc) {
 115                 goto end;
 116         }
 117
 118         if (PyErr_GivenExceptionMatches(exc,
 119                         py_mod_bt2_exc_try_again_type)) {
 120                 status = __BT_FUNC_STATUS_AGAIN;
 121         } else if (PyErr_GivenExceptionMatches(exc,
 122                         py_mod_bt2_exc_stop_type)) {
 123                 status = __BT_FUNC_STATUS_END;
 124         } else if (PyErr_GivenExceptionMatches(exc,
 125                         py_mod_bt2_exc_unknown_object_type)) {
 126                 status = __BT_FUNC_STATUS_UNKNOWN_OBJECT;
 127         } else {
 128                 /*
 129                  * Unknown exception: convert to general error.
 130                  *
 131                  * Because we only want to fetch the log level when
 132                  * we actually get an exception, and not systematically
 133                  * when we call py_exc_to_status() (as py_exc_to_status()
 134                  * can return `__BT_FUNC_STATUS_OK`), we get it here
 135                  * depending on the actor's type.
 136                  */
 137                 if (self_component) {
 138                         active_log_level = get_self_component_log_level(
 139                                 self_component);
 140                 } else if (self_message_iterator) {
 141                         active_log_level = get_self_message_iterator_log_level(
 142                                 self_message_iterator);
 143                 }
 144
 145                 BT_ASSERT(active_log_level != -1);
 146                 log_exception_and_maybe_append_error(BT_LOG_WARNING,
 147                         active_log_level, true,
 148                         self_component_class, self_component,
 149                         self_message_iterator, module_name);
 150
 151                 if (PyErr_GivenExceptionMatches(exc,
 152                                 py_mod_bt2_exc_memory_error)) {
 153                         status = __BT_FUNC_STATUS_MEMORY_ERROR;
 154                 } else {
 155                         status = __BT_FUNC_STATUS_ERROR;
 156                 }
 157         }
 158
 159 end:
 160         PyErr_Clear();
 161         return status;
 162 }
 163
 164 static
 165 int py_exc_to_status_component_class(
 166                 bt_self_component_class *self_component_class,
 167                 int active_log_level)
 168 {
 169         return py_exc_to_status(self_component_class, NULL, NULL, NULL,
 170                 active_log_level);
 171 }
 172
 173 static
 174 int py_exc_to_status_component(bt_self_component *self_component)
 175 {
 176         return py_exc_to_status(NULL, self_component, NULL, NULL, -1);
 177 }
 178
 179 static
 180 int py_exc_to_status_message_iterator(
 181                 bt_self_message_iterator *self_message_iterator)
 182 {
 183         return py_exc_to_status(NULL, NULL, self_message_iterator, NULL, -1);
 184 }
 185
 186 /* Component class proxy methods (delegate to the attached Python object) */
 187
 188 static
 189 bt_component_class_init_method_status component_class_init(
 190                 bt_self_component *self_component,
 191                 void *self_component_v,
 192                 swig_type_info *self_comp_cls_type_swig_type,
 193                 const bt_value *params,
 194                 void *init_method_data)
 195 {
 196         const bt_component *component = bt_self_component_as_component(self_component);
 197         const bt_component_class *component_class = bt_component_borrow_class_const(component);
 198         bt_component_class_init_method_status status = __BT_FUNC_STATUS_OK;
 199         PyObject *py_cls = NULL;
 200         PyObject *py_comp = NULL;
 201         PyObject *py_params_ptr = NULL;
 202         PyObject *py_comp_ptr = NULL;
 203         bt_logging_level log_level = get_self_component_log_level(
 204                 self_component);
 205
 206         (void) init_method_data;
 207
 208         BT_ASSERT(self_component);
 209         BT_ASSERT(self_component_v);
 210         BT_ASSERT(self_comp_cls_type_swig_type);
 211
 212         /*
 213          * Get the user-defined Python class which created this
 214          * component's class in the first place (borrowed
 215          * reference).
 216          */
 217         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 218         if (!py_cls) {
 219                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 220                         "Cannot find Python class associated to native component class: "
 221                         "comp-cls-addr=%p", component_class);
 222                 goto error;
 223         }
 224
 225         /* Parameters pointer -> SWIG pointer Python object */
 226         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 227                 SWIGTYPE_p_bt_value, 0);
 228         if (!py_params_ptr) {
 229                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 230                         "Failed to create a SWIG pointer object.");
 231                 goto error;
 232         }
 233
 234         py_comp_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_v),
 235                 self_comp_cls_type_swig_type, 0);
 236         if (!py_comp_ptr) {
 237                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 238                         "Failed to create a SWIG pointer object.");
 239                 goto error;
 240         }
 241
 242         /*
 243          * Do the equivalent of this:
 244          *
 245          *     py_comp = py_cls._bt_init_from_native(py_comp_ptr, py_params_ptr)
 246          *
 247          * _UserComponentType._bt_init_from_native() calls the Python
 248          * component object's __init__() function.
 249          */
 250         py_comp = PyObject_CallMethod(py_cls,
 251                 "_bt_init_from_native", "(OO)", py_comp_ptr, py_params_ptr);
 252         if (!py_comp) {
 253                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_component,
 254                         "Failed to call Python class's _bt_init_from_native() method: "
 255                         "py-cls-addr=%p", py_cls);
 256                 status = py_exc_to_status_component(self_component);
 257                 goto end;
 258         }
 259
 260         /*
 261          * Our user Python component object is now fully created and
 262          * initialized by the user. Since we just created it, this
 263          * native component is its only (persistent) owner.
 264          */
 265         bt_self_component_set_data(self_component, py_comp);
 266         py_comp = NULL;
 267         goto end;
 268
 269 error:
 270         status = __BT_FUNC_STATUS_ERROR;
 271
 272         /*
 273          * Clear any exception: we're returning a bad status anyway. If
 274          * this call originated from Python (creation from a plugin's
 275          * component class, for example), then the user gets an
 276          * appropriate creation error.
 277          */
 278         PyErr_Clear();
 279
 280 end:
 281         Py_XDECREF(py_comp);
 282         Py_XDECREF(py_params_ptr);
 283         Py_XDECREF(py_comp_ptr);
 284         return status;
 285 }
 286
 287 /*
 288  * Method of bt_component_class_source to initialize a bt_self_component_source
 289  * of that class.
 290  */
 291
 292 static
 293 bt_component_class_init_method_status component_class_source_init(
 294                 bt_self_component_source *self_component_source,
 295                 const bt_value *params, void *init_method_data)
 296 {
 297         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 298         return component_class_init(
 299                 self_component,
 300                 self_component_source,
 301                 SWIGTYPE_p_bt_self_component_source,
 302                 params, init_method_data);
 303 }
 304
 305 static
 306 bt_component_class_init_method_status component_class_filter_init(
 307                 bt_self_component_filter *self_component_filter,
 308                 const bt_value *params, void *init_method_data)
 309 {
 310         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 311         return component_class_init(
 312                 self_component,
 313                 self_component_filter,
 314                 SWIGTYPE_p_bt_self_component_filter,
 315                 params, init_method_data);
 316 }
 317
 318 static
 319 bt_component_class_init_method_status component_class_sink_init(
 320                 bt_self_component_sink *self_component_sink,
 321                 const bt_value *params, void *init_method_data)
 322 {
 323         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 324         return component_class_init(
 325                 self_component,
 326                 self_component_sink,
 327                 SWIGTYPE_p_bt_self_component_sink,
 328                 params, init_method_data);
 329 }
 330
 331 static
 332 void component_class_finalize(bt_self_component *self_component)
 333 {
 334         PyObject *py_comp = bt_self_component_get_data(self_component);
 335         BT_ASSERT(py_comp);
 336
 337         /* Call user's _user_finalize() method */
 338         PyObject *py_method_result = PyObject_CallMethod(py_comp,
 339                 "_user_finalize", NULL);
 340
 341         if (PyErr_Occurred()) {
 342                 bt_logging_level log_level = get_self_component_log_level(
 343                         self_component);
 344
 345                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_component,
 346                         "User component's _user_finalize() method raised an exception: ignoring:");
 347                 logw_exception(log_level);
 348         }
 349
 350         /*
 351          * Ignore any exception raised by the _user_finalize() method
 352          * because it won't change anything at this point: the component
 353          * is being destroyed anyway.
 354          */
 355         PyErr_Clear();
 356         Py_XDECREF(py_method_result);
 357         Py_DECREF(py_comp);
 358 }
 359
 360 static
 361 void component_class_source_finalize(bt_self_component_source *self_component_source)
 362 {
 363         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 364         component_class_finalize(self_component);
 365 }
 366
 367 static
 368 void component_class_filter_finalize(bt_self_component_filter *self_component_filter)
 369 {
 370         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 371         component_class_finalize(self_component);
 372 }
 373
 374 static
 375 void component_class_sink_finalize(bt_self_component_sink *self_component_sink)
 376 {
 377         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 378         component_class_finalize(self_component);
 379 }
 380
 381 static
 382 bt_bool component_class_can_seek_beginning(
 383                 bt_self_message_iterator *self_message_iterator)
 384 {
 385         PyObject *py_iter;
 386         PyObject *py_result = NULL;
 387         bt_bool can_seek_beginning = false;
 388
 389         py_iter = bt_self_message_iterator_get_data(self_message_iterator);
 390         BT_ASSERT(py_iter);
 391
 392         py_result = PyObject_GetAttrString(py_iter, "_bt_can_seek_beginning_from_native");
 393
 394         BT_ASSERT(!py_result || PyBool_Check(py_result));
 395
 396         if (py_result) {
 397                 can_seek_beginning = PyObject_IsTrue(py_result);
 398         } else {
 399                 /*
 400                  * Once can_seek_beginning can report errors, convert the
 401                  * exception to a status.  For now, log and return false;
 402                  */
 403                 loge_exception_message_iterator(self_message_iterator);
 404                 PyErr_Clear();
 405         }
 406
 407         Py_XDECREF(py_result);
 408
 409         return can_seek_beginning;
 410 }
 411
 412 static
 413 bt_component_class_message_iterator_seek_beginning_method_status
 414 component_class_seek_beginning(bt_self_message_iterator *self_message_iterator)
 415 {
 416         PyObject *py_iter;
 417         PyObject *py_result;
 418         bt_component_class_message_iterator_seek_beginning_method_status status;
 419
 420         py_iter = bt_self_message_iterator_get_data(self_message_iterator);
 421         BT_ASSERT(py_iter);
 422         py_result = PyObject_CallMethod(py_iter, "_bt_seek_beginning_from_native",
 423                 NULL);
 424         BT_ASSERT(!py_result || py_result == Py_None);
 425         status = py_exc_to_status_message_iterator(self_message_iterator);
 426         Py_XDECREF(py_result);
 427         return status;
 428 }
 429
 430 static
 431 bt_component_class_port_connected_method_status component_class_port_connected(
 432                 bt_self_component *self_component,
 433                 void *self_component_port,
 434                 swig_type_info *self_component_port_swig_type,
 435                 bt_port_type self_component_port_type,
 436                 const void *other_port,
 437                 swig_type_info *other_port_swig_type)
 438 {
 439         bt_component_class_port_connected_method_status status;
 440         PyObject *py_comp = NULL;
 441         PyObject *py_self_port_ptr = NULL;
 442         PyObject *py_other_port_ptr = NULL;
 443         PyObject *py_method_result = NULL;
 444         bt_logging_level log_level = get_self_component_log_level(
 445                 self_component);
 446
 447         py_comp = bt_self_component_get_data(self_component);
 448         BT_ASSERT(py_comp);
 449         py_self_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_port),
 450                 self_component_port_swig_type, 0);
 451         if (!py_self_port_ptr) {
 452                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 453                         "Failed to create a SWIG pointer object.");
 454                 status = __BT_FUNC_STATUS_MEMORY_ERROR;
 455                 goto end;
 456         }
 457
 458         py_other_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(other_port),
 459                 other_port_swig_type, 0);
 460         if (!py_other_port_ptr) {
 461                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 462                         "Failed to create a SWIG pointer object.");
 463                 status = __BT_FUNC_STATUS_MEMORY_ERROR;
 464                 goto end;       }
 465
 466         py_method_result = PyObject_CallMethod(py_comp,
 467                 "_bt_port_connected_from_native", "(OiO)", py_self_port_ptr,
 468                 self_component_port_type, py_other_port_ptr);
 469         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 470         status = py_exc_to_status_component(self_component);
 471
 472 end:
 473         Py_XDECREF(py_self_port_ptr);
 474         Py_XDECREF(py_other_port_ptr);
 475         Py_XDECREF(py_method_result);
 476         return status;
 477 }
 478
 479 static
 480 bt_component_class_port_connected_method_status
 481 component_class_source_output_port_connected(
 482                 bt_self_component_source *self_component_source,
 483                 bt_self_component_port_output *self_component_port_output,
 484                 const bt_port_input *other_port_input)
 485 {
 486         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 487
 488         return component_class_port_connected(
 489                 self_component,
 490                 self_component_port_output,
 491                 SWIGTYPE_p_bt_self_component_port_output,
 492                 BT_PORT_TYPE_OUTPUT,
 493                 other_port_input,
 494                 SWIGTYPE_p_bt_port_input);
 495 }
 496
 497 static
 498 bt_component_class_port_connected_method_status
 499 component_class_filter_input_port_connected(
 500                 bt_self_component_filter *self_component_filter,
 501                 bt_self_component_port_input *self_component_port_input,
 502                 const bt_port_output *other_port_output)
 503 {
 504         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 505
 506         return component_class_port_connected(
 507                 self_component,
 508                 self_component_port_input,
 509                 SWIGTYPE_p_bt_self_component_port_input,
 510                 BT_PORT_TYPE_INPUT,
 511                 other_port_output,
 512                 SWIGTYPE_p_bt_port_output);
 513 }
 514
 515 static
 516 bt_component_class_port_connected_method_status
 517 component_class_filter_output_port_connected(
 518                 bt_self_component_filter *self_component_filter,
 519                 bt_self_component_port_output *self_component_port_output,
 520                 const bt_port_input *other_port_input)
 521 {
 522         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 523
 524         return component_class_port_connected(
 525                 self_component,
 526                 self_component_port_output,
 527                 SWIGTYPE_p_bt_self_component_port_output,
 528                 BT_PORT_TYPE_OUTPUT,
 529                 other_port_input,
 530                 SWIGTYPE_p_bt_port_input);
 531 }
 532
 533 static
 534 bt_component_class_port_connected_method_status
 535 component_class_sink_input_port_connected(
 536                 bt_self_component_sink *self_component_sink,
 537                 bt_self_component_port_input *self_component_port_input,
 538                 const bt_port_output *other_port_output)
 539 {
 540         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 541
 542         return component_class_port_connected(
 543                 self_component,
 544                 self_component_port_input,
 545                 SWIGTYPE_p_bt_self_component_port_input,
 546                 BT_PORT_TYPE_INPUT,
 547                 other_port_output,
 548                 SWIGTYPE_p_bt_port_output);
 549 }
 550
 551 static
 552 bt_component_class_sink_graph_is_configured_method_status
 553 component_class_sink_graph_is_configured(
 554                 bt_self_component_sink *self_component_sink)
 555 {
 556         PyObject *py_comp = NULL;
 557         PyObject *py_method_result = NULL;
 558         bt_component_class_sink_graph_is_configured_method_status status = __BT_FUNC_STATUS_OK;
 559         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 560
 561         py_comp = bt_self_component_get_data(self_component);
 562         py_method_result = PyObject_CallMethod(py_comp,
 563                 "_bt_graph_is_configured_from_native", NULL);
 564         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 565         status = py_exc_to_status_component(self_component);
 566         Py_XDECREF(py_method_result);
 567         return status;
 568 }
 569
 570 static
 571 bt_component_class_query_method_status component_class_query(
 572                 const bt_component_class *component_class,
 573                 bt_self_component_class *self_component_class,
 574                 bt_private_query_executor *priv_query_executor,
 575                 const char *object, const bt_value *params,
 576                 const bt_value **result)
 577 {
 578         PyObject *py_cls = NULL;
 579         PyObject *py_params_ptr = NULL;
 580         PyObject *py_priv_query_exec_ptr = NULL;
 581         PyObject *py_query_func = NULL;
 582         PyObject *py_object = NULL;
 583         PyObject *py_results_addr = NULL;
 584         bt_component_class_query_method_status status = __BT_FUNC_STATUS_OK;
 585         const bt_query_executor *query_exec =
 586                 bt_private_query_executor_as_query_executor_const(
 587                         priv_query_executor);
 588         bt_logging_level log_level =
 589                 bt_query_executor_get_logging_level(query_exec);
 590
 591         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 592         if (!py_cls) {
 593                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 594                         "Cannot find Python class associated to native component class: "
 595                         "comp-cls-addr=%p", component_class);
 596                 goto error;
 597         }
 598
 599         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 600                 SWIGTYPE_p_bt_value, 0);
 601         if (!py_params_ptr) {
 602                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 603                         "Failed to create a SWIG pointer object.");
 604                 goto error;
 605         }
 606
 607         py_priv_query_exec_ptr = SWIG_NewPointerObj(
 608                 SWIG_as_voidptr(priv_query_executor),
 609                 SWIGTYPE_p_bt_private_query_executor, 0);
 610         if (!py_priv_query_exec_ptr) {
 611                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 612                         "Failed to create a SWIG pointer object.");
 613                 goto error;
 614         }
 615
 616         py_object = SWIG_FromCharPtr(object);
 617         if (!py_object) {
 618                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 619                         "Failed to create a Python string.");
 620                 goto error;
 621         }
 622
 623         py_results_addr = PyObject_CallMethod(py_cls,
 624                 "_bt_query_from_native", "(OOO)", py_priv_query_exec_ptr,
 625                 py_object, py_params_ptr);
 626         if (!py_results_addr) {
 627                 BT_LOG_WRITE_CUR_LVL(BT_LOG_WARNING, log_level, BT_LOG_TAG,
 628                         "Failed to call Python class's _bt_query_from_native() method: "
 629                         "py-cls-addr=%p", py_cls);
 630                 status = py_exc_to_status_component_class(self_component_class,
 631                         log_level);
 632                 goto end;
 633         }
 634
 635         /*
 636          * The returned object, on success, is an integer object
 637          * (PyLong) containing the address of a BT value object (new
 638          * reference).
 639          */
 640         *result = PyLong_AsVoidPtr(py_results_addr);
 641         BT_ASSERT(!PyErr_Occurred());
 642         BT_ASSERT(*result);
 643         goto end;
 644
 645 error:
 646         PyErr_Clear();
 647         status = __BT_FUNC_STATUS_ERROR;
 648
 649 end:
 650         Py_XDECREF(py_params_ptr);
 651         Py_XDECREF(py_priv_query_exec_ptr);
 652         Py_XDECREF(py_query_func);
 653         Py_XDECREF(py_object);
 654         Py_XDECREF(py_results_addr);
 655         return status;
 656 }
 657
 658 static
 659 bt_component_class_query_method_status component_class_source_query(
 660                 bt_self_component_class_source *self_component_class_source,
 661                 bt_private_query_executor *priv_query_executor,
 662                 const char *object, const bt_value *params,
 663                 const bt_value **result)
 664 {
 665         const bt_component_class_source *component_class_source = bt_self_component_class_source_as_component_class_source(self_component_class_source);
 666         const bt_component_class *component_class = bt_component_class_source_as_component_class_const(component_class_source);
 667         bt_self_component_class *self_component_class = bt_self_component_class_source_as_self_component_class(self_component_class_source);
 668
 669         return component_class_query(component_class, self_component_class,
 670                 priv_query_executor, object, params, result);
 671 }
 672
 673 static
 674 bt_component_class_query_method_status component_class_filter_query(
 675                 bt_self_component_class_filter *self_component_class_filter,
 676                 bt_private_query_executor *priv_query_executor,
 677                 const char *object, const bt_value *params,
 678                 const bt_value **result)
 679 {
 680         const bt_component_class_filter *component_class_filter = bt_self_component_class_filter_as_component_class_filter(self_component_class_filter);
 681         const bt_component_class *component_class = bt_component_class_filter_as_component_class_const(component_class_filter);
 682         bt_self_component_class *self_component_class = bt_self_component_class_filter_as_self_component_class(self_component_class_filter);
 683
 684         return component_class_query(component_class, self_component_class,
 685                 priv_query_executor, object, params, result);
 686 }
 687
 688 static
 689 bt_component_class_query_method_status component_class_sink_query(
 690                 bt_self_component_class_sink *self_component_class_sink,
 691                 bt_private_query_executor *priv_query_executor,
 692                 const char *object, const bt_value *params,
 693                 const bt_value **result)
 694 {
 695         const bt_component_class_sink *component_class_sink = bt_self_component_class_sink_as_component_class_sink(self_component_class_sink);
 696         const bt_component_class *component_class = bt_component_class_sink_as_component_class_const(component_class_sink);
 697         bt_self_component_class *self_component_class = bt_self_component_class_sink_as_self_component_class(self_component_class_sink);
 698
 699         return component_class_query(component_class, self_component_class,
 700                 priv_query_executor, object, params, result);
 701 }
 702
 703 static
 704 bt_component_class_message_iterator_init_method_status
 705 component_class_message_iterator_init(
 706                 bt_self_message_iterator *self_message_iterator,
 707                 bt_self_component *self_component,
 708                 bt_self_component_port_output *self_component_port_output)
 709 {
 710         bt_component_class_message_iterator_init_method_status status = __BT_FUNC_STATUS_OK;
 711         PyObject *py_comp_cls = NULL;
 712         PyObject *py_iter_cls = NULL;
 713         PyObject *py_iter_ptr = NULL;
 714         PyObject *py_component_port_output_ptr = NULL;
 715         PyObject *py_init_method_result = NULL;
 716         PyObject *py_iter = NULL;
 717         PyObject *py_comp;
 718         bt_logging_level log_level = get_self_component_log_level(
 719                 self_component);
 720
 721         py_comp = bt_self_component_get_data(self_component);
 722
 723         /* Find user's Python message iterator class */
 724         py_comp_cls = PyObject_GetAttrString(py_comp, "__class__");
 725         if (!py_comp_cls) {
 726                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 727                         "Cannot get Python object's `__class__` attribute.");
 728                 goto python_error;
 729         }
 730
 731         py_iter_cls = PyObject_GetAttrString(py_comp_cls, "_iter_cls");
 732         if (!py_iter_cls) {
 733                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 734                         "Cannot get Python class's `_iter_cls` attribute.");
 735                 goto python_error;
 736         }
 737
 738         py_iter_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_message_iterator),
 739                 SWIGTYPE_p_bt_self_message_iterator, 0);
 740         if (!py_iter_ptr) {
 741                 const char *err = "Failed to create a SWIG pointer object.";
 742
 743                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 744                         "%s", err);
 745                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
 746                         self_message_iterator, err);
 747                 goto error;
 748         }
 749
 750         /*
 751          * Create object with borrowed native message iterator
 752          * reference:
 753          *
 754          *     py_iter = py_iter_cls.__new__(py_iter_cls, py_iter_ptr)
 755          */
 756         py_iter = PyObject_CallMethod(py_iter_cls, "__new__",
 757                 "(OO)", py_iter_cls, py_iter_ptr);
 758         if (!py_iter) {
 759                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 760                         "Failed to call Python class's __new__() method: "
 761                         "py-cls-addr=%p", py_iter_cls);
 762                 goto python_error;
 763         }
 764
 765         /*
 766          * Initialize object:
 767          *
 768          *     py_iter.__init__(self_output_port)
 769          *
 770          * through the _init_for_native helper static method.
 771          *
 772          * At this point, py_iter._ptr is set, so this initialization
 773          * function has access to self._component (which gives it the
 774          * user Python component object from which the iterator was
 775          * created).
 776          */
 777         py_component_port_output_ptr = SWIG_NewPointerObj(
 778                 SWIG_as_voidptr(self_component_port_output),
 779                 SWIGTYPE_p_bt_self_component_port_output, 0);
 780         if (!py_component_port_output_ptr) {
 781                 const char *err = "Failed to create a SWIG pointer object.";
 782
 783                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 784                         "%s", err);
 785                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
 786                         self_message_iterator, err);
 787                 goto error;
 788         }
 789
 790         py_init_method_result = PyObject_CallMethod(py_iter,
 791                 "_bt_init_from_native", "O", py_component_port_output_ptr);
 792         if (!py_init_method_result) {
 793                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 794                         "User's __init__() method failed:");
 795                 goto python_error;
 796         }
 797
 798         /*
 799          * Since the Python code can never instantiate a user-defined
 800          * message iterator class, the native message iterator
 801          * object does NOT belong to a user Python message iterator
 802          * object (borrowed reference). However this Python object is
 803          * owned by this native message iterator object.
 804          *
 805          * In the Python world, the lifetime of the native message
 806          * iterator is managed by a _GenericMessageIterator
 807          * instance:
 808          *
 809          *     _GenericMessageIterator instance:
 810          *         owns a native bt_message_iterator object (iter)
 811          *             owns a _UserMessageIterator instance (py_iter)
 812          *                 self._ptr is a borrowed reference to the
 813          *                 native bt_private_connection_private_message_iterator
 814          *                 object (iter)
 815          */
 816         bt_self_message_iterator_set_data(self_message_iterator, py_iter);
 817         py_iter = NULL;
 818         goto end;
 819
 820 python_error:
 821         /* Handling of errors that cause a Python exception to be set. */
 822         status = py_exc_to_status_message_iterator(self_message_iterator);
 823         BT_ASSERT(status != __BT_FUNC_STATUS_OK);
 824         goto end;
 825
 826 error:
 827         /* Handling of errors that don't cause a Python exception to be set. */
 828         status = __BT_FUNC_STATUS_ERROR;
 829
 830 end:
 831         BT_ASSERT(!PyErr_Occurred());
 832
 833         Py_XDECREF(py_comp_cls);
 834         Py_XDECREF(py_iter_cls);
 835         Py_XDECREF(py_iter_ptr);
 836         Py_XDECREF(py_component_port_output_ptr);
 837         Py_XDECREF(py_init_method_result);
 838         Py_XDECREF(py_iter);
 839         return status;
 840 }
 841
 842 static
 843 bt_component_class_message_iterator_init_method_status
 844 component_class_source_message_iterator_init(
 845                 bt_self_message_iterator *self_message_iterator,
 846                 bt_self_component_source *self_component_source,
 847                 bt_self_component_port_output *self_component_port_output)
 848 {
 849         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 850
 851         return component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
 852 }
 853
 854 static
 855 bt_component_class_message_iterator_init_method_status
 856 component_class_filter_message_iterator_init(
 857                 bt_self_message_iterator *self_message_iterator,
 858                 bt_self_component_filter *self_component_filter,
 859                 bt_self_component_port_output *self_component_port_output)
 860 {
 861         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 862
 863         return component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
 864 }
 865
 866 static
 867 void component_class_message_iterator_finalize(
 868                 bt_self_message_iterator *message_iterator)
 869 {
 870         PyObject *py_message_iter = bt_self_message_iterator_get_data(
 871                 message_iterator);
 872         PyObject *py_method_result = NULL;
 873
 874         BT_ASSERT(py_message_iter);
 875
 876         /* Call user's _user_finalize() method */
 877         py_method_result = PyObject_CallMethod(py_message_iter,
 878                 "_user_finalize", NULL);
 879
 880         if (PyErr_Occurred()) {
 881                 bt_self_component *self_comp =
 882                         bt_self_message_iterator_borrow_component(
 883                                 message_iterator);
 884                 bt_logging_level log_level = get_self_component_log_level(
 885                         self_comp);
 886
 887                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_comp,
 888                         "User's _user_finalize() method raised an exception: ignoring:");
 889                 logw_exception(get_self_message_iterator_log_level(
 890                         message_iterator));
 891         }
 892
 893         /*
 894          * Ignore any exception raised by the _user_finalize() method
 895          * because it won't change anything at this point: the component
 896          * is being destroyed anyway.
 897          */
 898         PyErr_Clear();
 899         Py_XDECREF(py_method_result);
 900         Py_DECREF(py_message_iter);
 901 }
 902
 903 /* Valid for both sources and filters. */
 904
 905 static
 906 bt_component_class_message_iterator_next_method_status
 907 component_class_message_iterator_next(
 908                 bt_self_message_iterator *message_iterator,
 909                 bt_message_array_const msgs, uint64_t capacity,
 910                 uint64_t *count)
 911 {
 912         bt_component_class_message_iterator_next_method_status status = __BT_FUNC_STATUS_OK;
 913         PyObject *py_message_iter = bt_self_message_iterator_get_data(message_iterator);
 914         PyObject *py_method_result = NULL;
 915
 916         BT_ASSERT(py_message_iter);
 917         py_method_result = PyObject_CallMethod(py_message_iter,
 918                 "_bt_next_from_native", NULL);
 919         if (!py_method_result) {
 920                 status = py_exc_to_status_message_iterator(message_iterator);
 921                 BT_ASSERT(status != __BT_FUNC_STATUS_OK);
 922                 goto end;
 923         }
 924
 925         /*
 926          * The returned object, on success, is an integer object
 927          * (PyLong) containing the address of a native message
 928          * object (which is now ours).
 929          */
 930         msgs[0] = PyLong_AsVoidPtr(py_method_result);
 931         *count = 1;
 932
 933         /* Clear potential overflow error; should never happen */
 934         BT_ASSERT(!PyErr_Occurred());
 935         goto end;
 936
 937 end:
 938         Py_XDECREF(py_method_result);
 939         return status;
 940 }
 941
 942 static
 943 bt_component_class_sink_consume_method_status
 944 component_class_sink_consume(bt_self_component_sink *self_component_sink)
 945 {
 946         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 947         PyObject *py_comp = bt_self_component_get_data(self_component);
 948         PyObject *py_method_result = NULL;
 949         bt_component_class_sink_consume_method_status status;
 950
 951         BT_ASSERT(py_comp);
 952         py_method_result = PyObject_CallMethod(py_comp,
 953                 "_user_consume", NULL);
 954         status = py_exc_to_status_component(self_component);
 955         BT_ASSERT(py_method_result || status != __BT_FUNC_STATUS_OK);
 956         Py_XDECREF(py_method_result);
 957         return status;
 958 }
 959
 960 static
 961 int component_class_set_help_and_desc(
 962                 bt_component_class *component_class,
 963                 const char *description, const char *help)
 964 {
 965         int ret;
 966
 967         if (description) {
 968                 ret = bt_component_class_set_description(component_class, description);
 969                 if (ret) {
 970                         BT_LOGE("Cannot set component class's description: "
 971                                 "comp-cls-addr=%p", component_class);
 972                         goto end;
 973                 }
 974         }
 975
 976         if (help) {
 977                 ret = bt_component_class_set_help(component_class, help);
 978                 if (ret) {
 979                         BT_LOGE("Cannot set component class's help text: "
 980                                 "comp-cls-addr=%p", component_class);
 981                         goto end;
 982                 }
 983         }
 984
 985         ret = 0;
 986
 987 end:
 988         return ret;
 989 }
 990
 991 static
 992 bt_component_class_source *bt_bt2_component_class_source_create(
 993                 PyObject *py_cls, const char *name, const char *description,
 994                 const char *help)
 995 {
 996         bt_component_class_source *component_class_source;
 997         bt_component_class *component_class;
 998         int ret;
 999
1000         BT_ASSERT(py_cls);
1001         component_class_source = bt_component_class_source_create(name,
1002                 component_class_message_iterator_next);
1003         if (!component_class_source) {
1004                 BT_LOGE_STR("Cannot create source component class.");
1005                 goto end;
1006         }
1007
1008         component_class = bt_component_class_source_as_component_class(component_class_source);
1009
1010         if (component_class_set_help_and_desc(component_class, description, help)) {
1011                 goto end;
1012         }
1013
1014         ret = bt_component_class_source_set_init_method(component_class_source, component_class_source_init);
1015         BT_ASSERT(ret == 0);
1016         ret = bt_component_class_source_set_finalize_method(component_class_source, component_class_source_finalize);
1017         BT_ASSERT(ret == 0);
1018         ret = bt_component_class_source_set_message_iterator_can_seek_beginning_method(component_class_source,
1019                 component_class_can_seek_beginning);
1020         BT_ASSERT(ret == 0);
1021         ret = bt_component_class_source_set_message_iterator_seek_beginning_method(component_class_source,
1022                 component_class_seek_beginning);
1023         BT_ASSERT(ret == 0);
1024         ret = bt_component_class_source_set_output_port_connected_method(component_class_source,
1025                 component_class_source_output_port_connected);
1026         BT_ASSERT(ret == 0);
1027         ret = bt_component_class_source_set_query_method(component_class_source, component_class_source_query);
1028         BT_ASSERT(ret == 0);
1029         ret = bt_component_class_source_set_message_iterator_init_method(
1030                 component_class_source, component_class_source_message_iterator_init);
1031         BT_ASSERT(ret == 0);
1032         ret = bt_component_class_source_set_message_iterator_finalize_method(
1033                 component_class_source, component_class_message_iterator_finalize);
1034         BT_ASSERT(ret == 0);
1035         register_cc_ptr_to_py_cls(component_class, py_cls);
1036
1037 end:
1038         return component_class_source;
1039 }
1040
1041 static
1042 bt_component_class_filter *bt_bt2_component_class_filter_create(
1043                 PyObject *py_cls, const char *name, const char *description,
1044                 const char *help)
1045 {
1046         bt_component_class *component_class;
1047         bt_component_class_filter *component_class_filter;
1048         int ret;
1049
1050         BT_ASSERT(py_cls);
1051         component_class_filter = bt_component_class_filter_create(name,
1052                 component_class_message_iterator_next);
1053         if (!component_class_filter) {
1054                 BT_LOGE_STR("Cannot create filter component class.");
1055                 goto end;
1056         }
1057
1058         component_class = bt_component_class_filter_as_component_class(component_class_filter);
1059
1060         if (component_class_set_help_and_desc(component_class, description, help)) {
1061                 goto end;
1062         }
1063
1064         ret = bt_component_class_filter_set_init_method(component_class_filter, component_class_filter_init);
1065         BT_ASSERT(ret == 0);
1066         ret = bt_component_class_filter_set_finalize_method (component_class_filter, component_class_filter_finalize);
1067         BT_ASSERT(ret == 0);
1068         ret = bt_component_class_filter_set_message_iterator_can_seek_beginning_method(component_class_filter,
1069                 component_class_can_seek_beginning);
1070         BT_ASSERT(ret == 0);
1071         ret = bt_component_class_filter_set_message_iterator_seek_beginning_method(component_class_filter,
1072                 component_class_seek_beginning);
1073         BT_ASSERT(ret == 0);
1074         ret = bt_component_class_filter_set_input_port_connected_method(component_class_filter,
1075                 component_class_filter_input_port_connected);
1076         BT_ASSERT(ret == 0);
1077         ret = bt_component_class_filter_set_output_port_connected_method(component_class_filter,
1078                 component_class_filter_output_port_connected);
1079         BT_ASSERT(ret == 0);
1080         ret = bt_component_class_filter_set_query_method(component_class_filter, component_class_filter_query);
1081         BT_ASSERT(ret == 0);
1082         ret = bt_component_class_filter_set_message_iterator_init_method(
1083                 component_class_filter, component_class_filter_message_iterator_init);
1084         BT_ASSERT(ret == 0);
1085         ret = bt_component_class_filter_set_message_iterator_finalize_method(
1086                 component_class_filter, component_class_message_iterator_finalize);
1087         BT_ASSERT(ret == 0);
1088         register_cc_ptr_to_py_cls(component_class, py_cls);
1089
1090 end:
1091         return component_class_filter;
1092 }
1093
1094 static
1095 bt_component_class_sink *bt_bt2_component_class_sink_create(
1096                 PyObject *py_cls, const char *name, const char *description,
1097                 const char *help)
1098 {
1099         bt_component_class_sink *component_class_sink;
1100         bt_component_class *component_class;
1101         int ret;
1102
1103         BT_ASSERT(py_cls);
1104         component_class_sink = bt_component_class_sink_create(name, component_class_sink_consume);
1105
1106         if (!component_class_sink) {
1107                 BT_LOGE_STR("Cannot create sink component class.");
1108                 goto end;
1109         }
1110
1111         component_class = bt_component_class_sink_as_component_class(component_class_sink);
1112
1113         if (component_class_set_help_and_desc(component_class, description, help)) {
1114                 goto end;
1115         }
1116
1117         ret = bt_component_class_sink_set_init_method(component_class_sink, component_class_sink_init);
1118         BT_ASSERT(ret == 0);
1119         ret = bt_component_class_sink_set_finalize_method(component_class_sink, component_class_sink_finalize);
1120         BT_ASSERT(ret == 0);
1121         ret = bt_component_class_sink_set_input_port_connected_method(component_class_sink,
1122                 component_class_sink_input_port_connected);
1123         BT_ASSERT(ret == 0);
1124         ret = bt_component_class_sink_set_graph_is_configured_method(component_class_sink,
1125                 component_class_sink_graph_is_configured);
1126         BT_ASSERT(ret == 0);
1127         ret = bt_component_class_sink_set_query_method(component_class_sink, component_class_sink_query);
1128         BT_ASSERT(ret == 0);
1129         register_cc_ptr_to_py_cls(component_class, py_cls);
1130
1131 end:
1132         return component_class_sink;
1133 }