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