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 #include "compat/glib.h"
  27
  28 /*
  29  * This hash table associates a BT component class object address to a
  30  * user-defined Python class (PyObject *). The keys and values are NOT
  31  * owned by this hash table. The Python class objects are owned by the
  32  * Python module, which should not be unloaded until it is not possible
  33  * to create a user Python component anyway.
  34  *
  35  * This hash table is written to when a user-defined Python component
  36  * class is created by one of the bt_bt2_component_class_*_create()
  37  * functions.
  38  *
  39  * This function is read from when a user calls bt_component_create()
  40  * with a component class pointer created by one of the functions above.
  41  * In this case, the original Python class needs to be found to
  42  * instantiate it and associate the created Python component object with
  43  * a BT component object instance.
  44  */
  45
  46 static GHashTable *bt_cc_ptr_to_py_cls;
  47
  48 static
  49 void bt_bt2_unregister_cc_ptr_to_py_cls(const bt_component_class *comp_cls)
  50 {
  51         gboolean existed;
  52
  53         if (!bt_cc_ptr_to_py_cls) {
  54                 return;
  55         }
  56
  57         existed = g_hash_table_remove(bt_cc_ptr_to_py_cls, comp_cls);
  58         BT_ASSERT(existed);
  59 }
  60
  61 static
  62 void register_cc_ptr_to_py_cls(struct bt_component_class *bt_cc,
  63                 PyObject *py_cls)
  64 {
  65         if (!bt_cc_ptr_to_py_cls) {
  66                 /*
  67                  * Lazy-initializing this GHashTable because GLib
  68                  * might not be initialized yet and it needs to be
  69                  * before we call g_hash_table_new()
  70                  */
  71                 BT_LOGD_STR("Creating native component class to Python component class hash table.");
  72                 bt_cc_ptr_to_py_cls = g_hash_table_new(g_direct_hash, g_direct_equal);
  73                 BT_ASSERT(bt_cc_ptr_to_py_cls);
  74         }
  75
  76         g_hash_table_insert(bt_cc_ptr_to_py_cls, (gpointer) bt_cc,
  77                 (gpointer) py_cls);
  78 }
  79
  80 static
  81 PyObject *lookup_cc_ptr_to_py_cls(const bt_component_class *bt_cc)
  82 {
  83         if (!bt_cc_ptr_to_py_cls) {
  84                 BT_LOGW("Cannot look up Python component class because hash table is NULL: "
  85                         "comp-cls-addr=%p", bt_cc);
  86                 return NULL;
  87         }
  88
  89         return (PyObject *) g_hash_table_lookup(bt_cc_ptr_to_py_cls,
  90                 (gconstpointer) bt_cc);
  91 }
  92
  93 /* Library destructor */
  94
  95 __attribute__((destructor))
  96 static
  97 void native_comp_class_dtor(void) {
  98         /* Destroy component class association hash table */
  99         if (bt_cc_ptr_to_py_cls) {
 100                 BT_LOGD_STR("Destroying native component class to Python component class hash table.");
 101                 g_hash_table_destroy(bt_cc_ptr_to_py_cls);
 102                 bt_cc_ptr_to_py_cls = NULL;
 103         }
 104 }
 105
 106 static inline
 107 int py_exc_to_status(bt_self_component_class *self_component_class,
 108                 bt_self_component *self_component,
 109                 bt_self_message_iterator *self_message_iterator,
 110                 const char *module_name, int active_log_level)
 111 {
 112         int status = __BT_FUNC_STATUS_OK;
 113         PyObject *exc = PyErr_Occurred();
 114
 115         if (!exc) {
 116                 goto end;
 117         }
 118
 119         if (PyErr_GivenExceptionMatches(exc,
 120                         py_mod_bt2_exc_try_again_type)) {
 121                 status = __BT_FUNC_STATUS_AGAIN;
 122         } else if (PyErr_GivenExceptionMatches(exc,
 123                         py_mod_bt2_exc_stop_type)) {
 124                 status = __BT_FUNC_STATUS_END;
 125         } else if (PyErr_GivenExceptionMatches(exc,
 126                         py_mod_bt2_exc_unknown_object_type)) {
 127                 status = __BT_FUNC_STATUS_UNKNOWN_OBJECT;
 128         } else {
 129                 /*
 130                  * Unknown exception: convert to general error.
 131                  *
 132                  * Because we only want to fetch the log level when
 133                  * we actually get an exception, and not systematically
 134                  * when we call py_exc_to_status() (as py_exc_to_status()
 135                  * can return `__BT_FUNC_STATUS_OK`), we get it here
 136                  * depending on the actor's type.
 137                  */
 138                 if (self_component) {
 139                         active_log_level = get_self_component_log_level(
 140                                 self_component);
 141                 } else if (self_message_iterator) {
 142                         active_log_level = get_self_message_iterator_log_level(
 143                                 self_message_iterator);
 144                 }
 145
 146                 BT_ASSERT(active_log_level != -1);
 147                 log_exception_and_maybe_append_error(BT_LOG_WARNING,
 148                         active_log_level, true,
 149                         self_component_class, self_component,
 150                         self_message_iterator, module_name);
 151
 152                 if (PyErr_GivenExceptionMatches(exc,
 153                                 py_mod_bt2_exc_memory_error)) {
 154                         status = __BT_FUNC_STATUS_MEMORY_ERROR;
 155                 } else {
 156                         status = __BT_FUNC_STATUS_ERROR;
 157                 }
 158         }
 159
 160 end:
 161         PyErr_Clear();
 162         return status;
 163 }
 164
 165 static
 166 int py_exc_to_status_component_class(
 167                 bt_self_component_class *self_component_class,
 168                 int active_log_level)
 169 {
 170         return py_exc_to_status(self_component_class, NULL, NULL, NULL,
 171                 active_log_level);
 172 }
 173
 174 static
 175 int py_exc_to_status_component(bt_self_component *self_component)
 176 {
 177         return py_exc_to_status(NULL, self_component, NULL, NULL, -1);
 178 }
 179
 180 static
 181 int py_exc_to_status_message_iterator(
 182                 bt_self_message_iterator *self_message_iterator)
 183 {
 184         return py_exc_to_status(NULL, NULL, self_message_iterator, NULL, -1);
 185 }
 186
 187 static
 188 bool bt_bt2_is_python_component_class(const bt_component_class *comp_cls)
 189 {
 190         return bt_g_hash_table_contains(bt_cc_ptr_to_py_cls, comp_cls);
 191 }
 192
 193 /* Component class proxy methods (delegate to the attached Python object) */
 194
 195 static
 196 bt_component_class_init_method_status component_class_init(
 197                 bt_self_component *self_component,
 198                 void *self_component_v,
 199                 swig_type_info *self_comp_cls_type_swig_type,
 200                 const bt_value *params,
 201                 void *init_method_data)
 202 {
 203         const bt_component *component = bt_self_component_as_component(self_component);
 204         const bt_component_class *component_class = bt_component_borrow_class_const(component);
 205         bt_component_class_init_method_status status = __BT_FUNC_STATUS_OK;
 206         PyObject *py_cls = NULL;
 207         PyObject *py_comp = NULL;
 208         PyObject *py_params_ptr = NULL;
 209         PyObject *py_comp_ptr = NULL;
 210         bt_logging_level log_level = get_self_component_log_level(
 211                 self_component);
 212
 213         BT_ASSERT(self_component);
 214         BT_ASSERT(self_component_v);
 215         BT_ASSERT(self_comp_cls_type_swig_type);
 216
 217         /*
 218          * Get the user-defined Python class which created this
 219          * component's class in the first place (borrowed
 220          * reference).
 221          */
 222         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 223         if (!py_cls) {
 224                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 225                         "Cannot find Python class associated to native component class: "
 226                         "comp-cls-addr=%p", component_class);
 227                 goto error;
 228         }
 229
 230         /* Parameters pointer -> SWIG pointer Python object */
 231         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 232                 SWIGTYPE_p_bt_value, 0);
 233         if (!py_params_ptr) {
 234                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 235                         "Failed to create a SWIG pointer object.");
 236                 goto error;
 237         }
 238
 239         py_comp_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_v),
 240                 self_comp_cls_type_swig_type, 0);
 241         if (!py_comp_ptr) {
 242                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 243                         "Failed to create a SWIG pointer object.");
 244                 goto error;
 245         }
 246
 247         /*
 248          * Do the equivalent of this:
 249          *
 250          *     py_comp = py_cls._bt_init_from_native(py_comp_ptr,
 251          *         py_params_ptr, init_method_data ? init_method_data : Py_None)
 252          *
 253          * _UserComponentType._bt_init_from_native() calls the Python
 254          * component object's __init__() function.
 255          *
 256          * We don't take any reference on `init_method_data` which, if
 257          * not `NULL`, is assumed to be a `PyObject *`: the user's
 258          * __init__() function will eventually take a reference if
 259          * needed. If `init_method_data` is `NULL`, then we pass
 260          * `Py_None` as the initialization's Python object.
 261          */
 262         py_comp = PyObject_CallMethod(py_cls,
 263                 "_bt_init_from_native", "(OOO)", py_comp_ptr, py_params_ptr,
 264                 init_method_data ? init_method_data : Py_None);
 265         if (!py_comp) {
 266                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_component,
 267                         "Failed to call Python class's _bt_init_from_native() method: "
 268                         "py-cls-addr=%p", py_cls);
 269                 status = py_exc_to_status_component(self_component);
 270                 goto end;
 271         }
 272
 273         /*
 274          * Our user Python component object is now fully created and
 275          * initialized by the user. Since we just created it, this
 276          * native component is its only (persistent) owner.
 277          */
 278         bt_self_component_set_data(self_component, py_comp);
 279         py_comp = NULL;
 280         goto end;
 281
 282 error:
 283         status = __BT_FUNC_STATUS_ERROR;
 284
 285         /*
 286          * Clear any exception: we're returning a bad status anyway. If
 287          * this call originated from Python (creation from a plugin's
 288          * component class, for example), then the user gets an
 289          * appropriate creation error.
 290          */
 291         PyErr_Clear();
 292
 293 end:
 294         Py_XDECREF(py_comp);
 295         Py_XDECREF(py_params_ptr);
 296         Py_XDECREF(py_comp_ptr);
 297         return status;
 298 }
 299
 300 static
 301 bt_component_class_get_supported_mip_versions_method_status
 302 component_class_get_supported_mip_versions(
 303                 const bt_component_class *component_class,
 304                 bt_self_component_class *self_component_class,
 305                 const bt_value *params, void *init_method_data,
 306                 bt_logging_level log_level,
 307                 bt_integer_range_set_unsigned *supported_versions)
 308 {
 309         uint64_t i;
 310         PyObject *py_cls = NULL;
 311         PyObject *py_params_ptr = NULL;
 312         PyObject *py_range_set_addr = NULL;
 313         bt_integer_range_set_unsigned *ret_range_set = NULL;
 314         bt_component_class_get_supported_mip_versions_method_status status =
 315                 __BT_FUNC_STATUS_OK;
 316
 317         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 318         if (!py_cls) {
 319                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 320                         "Cannot find Python class associated to native component class: "
 321                         "comp-cls-addr=%p", component_class);
 322                 goto error;
 323         }
 324
 325         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 326                 SWIGTYPE_p_bt_value, 0);
 327         if (!py_params_ptr) {
 328                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 329                         "Failed to create a SWIG pointer object.");
 330                 goto error;
 331         }
 332
 333         /*
 334          * We don't take any reference on `init_method_data` which, if
 335          * not `NULL`, is assumed to be a `PyObject *`: the user's
 336          * _user_get_supported_mip_versions() function will eventually
 337          * take a reference if needed. If `init_method_data` is `NULL`,
 338          * then we pass `Py_None` as the initialization's Python object.
 339          */
 340         py_range_set_addr = PyObject_CallMethod(py_cls,
 341                 "_bt_get_supported_mip_versions_from_native", "(OOi)",
 342                 py_params_ptr, init_method_data ? init_method_data : Py_None,
 343                 (int) log_level);
 344         if (!py_range_set_addr) {
 345                 BT_LOG_WRITE_CUR_LVL(BT_LOG_WARNING, log_level, BT_LOG_TAG,
 346                         "Failed to call Python class's _bt_get_supported_mip_versions_from_native() method: "
 347                         "py-cls-addr=%p", py_cls);
 348                 status = py_exc_to_status_component_class(self_component_class,
 349                         log_level);
 350                 goto end;
 351         }
 352
 353         /*
 354          * The returned object, on success, is an integer object
 355          * (PyLong) containing the address of a BT unsigned integer
 356          * range set object (new reference).
 357          */
 358         ret_range_set = PyLong_AsVoidPtr(py_range_set_addr);
 359         BT_ASSERT(!PyErr_Occurred());
 360         BT_ASSERT(ret_range_set);
 361
 362         /* Copy returned ranges to input range set */
 363         for (i = 0; i < bt_integer_range_set_get_range_count(
 364                         bt_integer_range_set_unsigned_as_range_set_const(ret_range_set));
 365                         i++) {
 366                 const bt_integer_range_unsigned *range =
 367                         bt_integer_range_set_unsigned_borrow_range_by_index_const(
 368                                 ret_range_set, i);
 369                 bt_integer_range_set_add_range_status add_range_status;
 370
 371                 add_range_status = bt_integer_range_set_unsigned_add_range(
 372                         supported_versions,
 373                         bt_integer_range_unsigned_get_lower(range),
 374                         bt_integer_range_unsigned_get_upper(range));
 375                 if (add_range_status) {
 376                         BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 377                                 "Failed to add range to supported MIP versions range set.");
 378                         goto error;
 379                 }
 380         }
 381
 382         goto end;
 383
 384 error:
 385         PyErr_Clear();
 386         status = __BT_FUNC_STATUS_ERROR;
 387
 388 end:
 389         Py_XDECREF(py_params_ptr);
 390         Py_XDECREF(py_range_set_addr);
 391         bt_integer_range_set_unsigned_put_ref(ret_range_set);
 392         return status;
 393 }
 394
 395 static
 396 bt_component_class_get_supported_mip_versions_method_status
 397 component_class_source_get_supported_mip_versions(
 398                 bt_self_component_class_source *self_component_class_source,
 399                 const bt_value *params, void *init_method_data,
 400                 bt_logging_level log_level,
 401                 bt_integer_range_set_unsigned *supported_versions)
 402 {
 403         const bt_component_class_source *component_class_source = bt_self_component_class_source_as_component_class_source(self_component_class_source);
 404         const bt_component_class *component_class = bt_component_class_source_as_component_class_const(component_class_source);
 405         bt_self_component_class *self_component_class = bt_self_component_class_source_as_self_component_class(self_component_class_source);
 406
 407         return component_class_get_supported_mip_versions(
 408                 component_class, self_component_class,
 409                 params, init_method_data, log_level, supported_versions);
 410 }
 411
 412 static
 413 bt_component_class_get_supported_mip_versions_method_status
 414 component_class_filter_get_supported_mip_versions(
 415                 bt_self_component_class_filter *self_component_class_filter,
 416                 const bt_value *params, void *init_method_data,
 417                 bt_logging_level log_level,
 418                 bt_integer_range_set_unsigned *supported_versions)
 419 {
 420         const bt_component_class_filter *component_class_filter = bt_self_component_class_filter_as_component_class_filter(self_component_class_filter);
 421         const bt_component_class *component_class = bt_component_class_filter_as_component_class_const(component_class_filter);
 422         bt_self_component_class *self_component_class = bt_self_component_class_filter_as_self_component_class(self_component_class_filter);
 423
 424         return component_class_get_supported_mip_versions(
 425                 component_class, self_component_class,
 426                 params, init_method_data, log_level, supported_versions);
 427 }
 428
 429 static
 430 bt_component_class_get_supported_mip_versions_method_status
 431 component_class_sink_get_supported_mip_versions(
 432                 bt_self_component_class_sink *self_component_class_sink,
 433                 const bt_value *params, void *init_method_data,
 434                 bt_logging_level log_level,
 435                 bt_integer_range_set_unsigned *supported_versions)
 436 {
 437         const bt_component_class_sink *component_class_sink = bt_self_component_class_sink_as_component_class_sink(self_component_class_sink);
 438         const bt_component_class *component_class = bt_component_class_sink_as_component_class_const(component_class_sink);
 439         bt_self_component_class *self_component_class = bt_self_component_class_sink_as_self_component_class(self_component_class_sink);
 440
 441         return component_class_get_supported_mip_versions(
 442                 component_class, self_component_class,
 443                 params, init_method_data, log_level, supported_versions);
 444 }
 445
 446 /*
 447  * Method of bt_component_class_source to initialize a bt_self_component_source
 448  * of that class.
 449  */
 450
 451 static
 452 bt_component_class_init_method_status component_class_source_init(
 453                 bt_self_component_source *self_component_source,
 454                 const bt_value *params, void *init_method_data)
 455 {
 456         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 457         return component_class_init(
 458                 self_component,
 459                 self_component_source,
 460                 SWIGTYPE_p_bt_self_component_source,
 461                 params, init_method_data);
 462 }
 463
 464 static
 465 bt_component_class_init_method_status component_class_filter_init(
 466                 bt_self_component_filter *self_component_filter,
 467                 const bt_value *params, void *init_method_data)
 468 {
 469         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 470         return component_class_init(
 471                 self_component,
 472                 self_component_filter,
 473                 SWIGTYPE_p_bt_self_component_filter,
 474                 params, init_method_data);
 475 }
 476
 477 static
 478 bt_component_class_init_method_status component_class_sink_init(
 479                 bt_self_component_sink *self_component_sink,
 480                 const bt_value *params, void *init_method_data)
 481 {
 482         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 483         return component_class_init(
 484                 self_component,
 485                 self_component_sink,
 486                 SWIGTYPE_p_bt_self_component_sink,
 487                 params, init_method_data);
 488 }
 489
 490 static
 491 void component_class_finalize(bt_self_component *self_component)
 492 {
 493         PyObject *py_comp = bt_self_component_get_data(self_component);
 494         BT_ASSERT(py_comp);
 495
 496         /* Call user's _user_finalize() method */
 497         PyObject *py_method_result = PyObject_CallMethod(py_comp,
 498                 "_user_finalize", NULL);
 499
 500         if (PyErr_Occurred()) {
 501                 bt_logging_level log_level = get_self_component_log_level(
 502                         self_component);
 503
 504                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_component,
 505                         "User component's _user_finalize() method raised an exception: ignoring:");
 506                 logw_exception(log_level);
 507         }
 508
 509         /*
 510          * Ignore any exception raised by the _user_finalize() method
 511          * because it won't change anything at this point: the component
 512          * is being destroyed anyway.
 513          */
 514         PyErr_Clear();
 515         Py_XDECREF(py_method_result);
 516         Py_DECREF(py_comp);
 517 }
 518
 519 static
 520 void component_class_source_finalize(bt_self_component_source *self_component_source)
 521 {
 522         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 523         component_class_finalize(self_component);
 524 }
 525
 526 static
 527 void component_class_filter_finalize(bt_self_component_filter *self_component_filter)
 528 {
 529         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 530         component_class_finalize(self_component);
 531 }
 532
 533 static
 534 void component_class_sink_finalize(bt_self_component_sink *self_component_sink)
 535 {
 536         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 537         component_class_finalize(self_component);
 538 }
 539
 540 static
 541 bt_bool component_class_can_seek_beginning(
 542                 bt_self_message_iterator *self_message_iterator)
 543 {
 544         PyObject *py_iter;
 545         PyObject *py_result = NULL;
 546         bt_bool can_seek_beginning = false;
 547
 548         py_iter = bt_self_message_iterator_get_data(self_message_iterator);
 549         BT_ASSERT(py_iter);
 550
 551         py_result = PyObject_GetAttrString(py_iter, "_bt_can_seek_beginning_from_native");
 552
 553         BT_ASSERT(!py_result || PyBool_Check(py_result));
 554
 555         if (py_result) {
 556                 can_seek_beginning = PyObject_IsTrue(py_result);
 557         } else {
 558                 /*
 559                  * Once can_seek_beginning can report errors, convert the
 560                  * exception to a status.  For now, log and return false;
 561                  */
 562                 loge_exception_message_iterator(self_message_iterator);
 563                 PyErr_Clear();
 564         }
 565
 566         Py_XDECREF(py_result);
 567
 568         return can_seek_beginning;
 569 }
 570
 571 static
 572 bt_component_class_message_iterator_seek_beginning_method_status
 573 component_class_seek_beginning(bt_self_message_iterator *self_message_iterator)
 574 {
 575         PyObject *py_iter;
 576         PyObject *py_result;
 577         bt_component_class_message_iterator_seek_beginning_method_status status;
 578
 579         py_iter = bt_self_message_iterator_get_data(self_message_iterator);
 580         BT_ASSERT(py_iter);
 581         py_result = PyObject_CallMethod(py_iter, "_bt_seek_beginning_from_native",
 582                 NULL);
 583         BT_ASSERT(!py_result || py_result == Py_None);
 584         status = py_exc_to_status_message_iterator(self_message_iterator);
 585         Py_XDECREF(py_result);
 586         return status;
 587 }
 588
 589 static
 590 bt_component_class_port_connected_method_status component_class_port_connected(
 591                 bt_self_component *self_component,
 592                 void *self_component_port,
 593                 swig_type_info *self_component_port_swig_type,
 594                 bt_port_type self_component_port_type,
 595                 const void *other_port,
 596                 swig_type_info *other_port_swig_type)
 597 {
 598         bt_component_class_port_connected_method_status status;
 599         PyObject *py_comp = NULL;
 600         PyObject *py_self_port_ptr = NULL;
 601         PyObject *py_other_port_ptr = NULL;
 602         PyObject *py_method_result = NULL;
 603         bt_logging_level log_level = get_self_component_log_level(
 604                 self_component);
 605
 606         py_comp = bt_self_component_get_data(self_component);
 607         BT_ASSERT(py_comp);
 608         py_self_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_port),
 609                 self_component_port_swig_type, 0);
 610         if (!py_self_port_ptr) {
 611                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 612                         "Failed to create a SWIG pointer object.");
 613                 status = __BT_FUNC_STATUS_MEMORY_ERROR;
 614                 goto end;
 615         }
 616
 617         py_other_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(other_port),
 618                 other_port_swig_type, 0);
 619         if (!py_other_port_ptr) {
 620                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 621                         "Failed to create a SWIG pointer object.");
 622                 status = __BT_FUNC_STATUS_MEMORY_ERROR;
 623                 goto end;       }
 624
 625         py_method_result = PyObject_CallMethod(py_comp,
 626                 "_bt_port_connected_from_native", "(OiO)", py_self_port_ptr,
 627                 self_component_port_type, py_other_port_ptr);
 628         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 629         status = py_exc_to_status_component(self_component);
 630
 631 end:
 632         Py_XDECREF(py_self_port_ptr);
 633         Py_XDECREF(py_other_port_ptr);
 634         Py_XDECREF(py_method_result);
 635         return status;
 636 }
 637
 638 static
 639 bt_component_class_port_connected_method_status
 640 component_class_source_output_port_connected(
 641                 bt_self_component_source *self_component_source,
 642                 bt_self_component_port_output *self_component_port_output,
 643                 const bt_port_input *other_port_input)
 644 {
 645         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 646
 647         return component_class_port_connected(
 648                 self_component,
 649                 self_component_port_output,
 650                 SWIGTYPE_p_bt_self_component_port_output,
 651                 BT_PORT_TYPE_OUTPUT,
 652                 other_port_input,
 653                 SWIGTYPE_p_bt_port_input);
 654 }
 655
 656 static
 657 bt_component_class_port_connected_method_status
 658 component_class_filter_input_port_connected(
 659                 bt_self_component_filter *self_component_filter,
 660                 bt_self_component_port_input *self_component_port_input,
 661                 const bt_port_output *other_port_output)
 662 {
 663         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 664
 665         return component_class_port_connected(
 666                 self_component,
 667                 self_component_port_input,
 668                 SWIGTYPE_p_bt_self_component_port_input,
 669                 BT_PORT_TYPE_INPUT,
 670                 other_port_output,
 671                 SWIGTYPE_p_bt_port_output);
 672 }
 673
 674 static
 675 bt_component_class_port_connected_method_status
 676 component_class_filter_output_port_connected(
 677                 bt_self_component_filter *self_component_filter,
 678                 bt_self_component_port_output *self_component_port_output,
 679                 const bt_port_input *other_port_input)
 680 {
 681         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 682
 683         return component_class_port_connected(
 684                 self_component,
 685                 self_component_port_output,
 686                 SWIGTYPE_p_bt_self_component_port_output,
 687                 BT_PORT_TYPE_OUTPUT,
 688                 other_port_input,
 689                 SWIGTYPE_p_bt_port_input);
 690 }
 691
 692 static
 693 bt_component_class_port_connected_method_status
 694 component_class_sink_input_port_connected(
 695                 bt_self_component_sink *self_component_sink,
 696                 bt_self_component_port_input *self_component_port_input,
 697                 const bt_port_output *other_port_output)
 698 {
 699         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 700
 701         return component_class_port_connected(
 702                 self_component,
 703                 self_component_port_input,
 704                 SWIGTYPE_p_bt_self_component_port_input,
 705                 BT_PORT_TYPE_INPUT,
 706                 other_port_output,
 707                 SWIGTYPE_p_bt_port_output);
 708 }
 709
 710 static
 711 bt_component_class_sink_graph_is_configured_method_status
 712 component_class_sink_graph_is_configured(
 713                 bt_self_component_sink *self_component_sink)
 714 {
 715         PyObject *py_comp = NULL;
 716         PyObject *py_method_result = NULL;
 717         bt_component_class_sink_graph_is_configured_method_status status = __BT_FUNC_STATUS_OK;
 718         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 719
 720         py_comp = bt_self_component_get_data(self_component);
 721         py_method_result = PyObject_CallMethod(py_comp,
 722                 "_bt_graph_is_configured_from_native", NULL);
 723         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 724         status = py_exc_to_status_component(self_component);
 725         Py_XDECREF(py_method_result);
 726         return status;
 727 }
 728
 729 static
 730 bt_component_class_query_method_status component_class_query(
 731                 const bt_component_class *component_class,
 732                 bt_self_component_class *self_component_class,
 733                 bt_private_query_executor *priv_query_executor,
 734                 const char *object, const bt_value *params, void *method_data,
 735                 const bt_value **result)
 736 {
 737         PyObject *py_cls = NULL;
 738         PyObject *py_params_ptr = NULL;
 739         PyObject *py_priv_query_exec_ptr = NULL;
 740         PyObject *py_query_func = NULL;
 741         PyObject *py_object = NULL;
 742         PyObject *py_results_addr = NULL;
 743         bt_component_class_query_method_status status = __BT_FUNC_STATUS_OK;
 744         const bt_query_executor *query_exec =
 745                 bt_private_query_executor_as_query_executor_const(
 746                         priv_query_executor);
 747         bt_logging_level log_level =
 748                 bt_query_executor_get_logging_level(query_exec);
 749
 750         /*
 751          * If there's any `method_data`, assume this component class is
 752          * getting queried from Python, so that `method_data` is a
 753          * Python object to pass to the user's _user_query() method.
 754          */
 755         BT_ASSERT(!method_data ||
 756                         bt_bt2_is_python_component_class(component_class));
 757
 758         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 759         if (!py_cls) {
 760                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 761                         "Cannot find Python class associated to native component class: "
 762                         "comp-cls-addr=%p", component_class);
 763                 goto error;
 764         }
 765
 766         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 767                 SWIGTYPE_p_bt_value, 0);
 768         if (!py_params_ptr) {
 769                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 770                         "Failed to create a SWIG pointer object.");
 771                 goto error;
 772         }
 773
 774         py_priv_query_exec_ptr = SWIG_NewPointerObj(
 775                 SWIG_as_voidptr(priv_query_executor),
 776                 SWIGTYPE_p_bt_private_query_executor, 0);
 777         if (!py_priv_query_exec_ptr) {
 778                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 779                         "Failed to create a SWIG pointer object.");
 780                 goto error;
 781         }
 782
 783         py_object = SWIG_FromCharPtr(object);
 784         if (!py_object) {
 785                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 786                         "Failed to create a Python string.");
 787                 goto error;
 788         }
 789
 790         /*
 791          * We don't take any reference on `method_data` which, if not
 792          * `NULL`, is assumed to be a `PyObject *`: the user's
 793          * _user_query() function will eventually take a reference if
 794          * needed. If `method_data` is `NULL`, then we pass `Py_None` as
 795          * the initialization's Python object.
 796          */
 797         py_results_addr = PyObject_CallMethod(py_cls,
 798                 "_bt_query_from_native", "(OOOO)", py_priv_query_exec_ptr,
 799                 py_object, py_params_ptr,
 800                 method_data ? method_data : Py_None);
 801         if (!py_results_addr) {
 802                 status = py_exc_to_status_component_class(self_component_class,
 803                         log_level);
 804                 if (status < 0) {
 805                         static const char *fmt =
 806                                 "Failed to call Python class's _bt_query_from_native() method: py-cls-addr=%p";
 807                         BT_LOG_WRITE_CUR_LVL(BT_LOG_WARNING, log_level, BT_LOG_TAG,
 808                                 fmt, py_cls);
 809                         BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_COMPONENT_CLASS(
 810                                 self_component_class, fmt, py_cls);
 811                 }
 812                 goto end;
 813         }
 814
 815         /*
 816          * The returned object, on success, is an integer object
 817          * (PyLong) containing the address of a BT value object (new
 818          * reference).
 819          */
 820         *result = PyLong_AsVoidPtr(py_results_addr);
 821         BT_ASSERT(!PyErr_Occurred());
 822         BT_ASSERT(*result);
 823         goto end;
 824
 825 error:
 826         PyErr_Clear();
 827         status = __BT_FUNC_STATUS_ERROR;
 828
 829 end:
 830         Py_XDECREF(py_params_ptr);
 831         Py_XDECREF(py_priv_query_exec_ptr);
 832         Py_XDECREF(py_query_func);
 833         Py_XDECREF(py_object);
 834         Py_XDECREF(py_results_addr);
 835         return status;
 836 }
 837
 838 static
 839 bt_component_class_query_method_status component_class_source_query(
 840                 bt_self_component_class_source *self_component_class_source,
 841                 bt_private_query_executor *priv_query_executor,
 842                 const char *object, const bt_value *params, void *method_data,
 843                 const bt_value **result)
 844 {
 845         const bt_component_class_source *component_class_source = bt_self_component_class_source_as_component_class_source(self_component_class_source);
 846         const bt_component_class *component_class = bt_component_class_source_as_component_class_const(component_class_source);
 847         bt_self_component_class *self_component_class = bt_self_component_class_source_as_self_component_class(self_component_class_source);
 848
 849         return component_class_query(component_class, self_component_class,
 850                 priv_query_executor, object, params, method_data, result);
 851 }
 852
 853 static
 854 bt_component_class_query_method_status component_class_filter_query(
 855                 bt_self_component_class_filter *self_component_class_filter,
 856                 bt_private_query_executor *priv_query_executor,
 857                 const char *object, const bt_value *params, void *method_data,
 858                 const bt_value **result)
 859 {
 860         const bt_component_class_filter *component_class_filter = bt_self_component_class_filter_as_component_class_filter(self_component_class_filter);
 861         const bt_component_class *component_class = bt_component_class_filter_as_component_class_const(component_class_filter);
 862         bt_self_component_class *self_component_class = bt_self_component_class_filter_as_self_component_class(self_component_class_filter);
 863
 864         return component_class_query(component_class, self_component_class,
 865                 priv_query_executor, object, params, method_data, result);
 866 }
 867
 868 static
 869 bt_component_class_query_method_status component_class_sink_query(
 870                 bt_self_component_class_sink *self_component_class_sink,
 871                 bt_private_query_executor *priv_query_executor,
 872                 const char *object, const bt_value *params, void *method_data,
 873                 const bt_value **result)
 874 {
 875         const bt_component_class_sink *component_class_sink = bt_self_component_class_sink_as_component_class_sink(self_component_class_sink);
 876         const bt_component_class *component_class = bt_component_class_sink_as_component_class_const(component_class_sink);
 877         bt_self_component_class *self_component_class = bt_self_component_class_sink_as_self_component_class(self_component_class_sink);
 878
 879         return component_class_query(component_class, self_component_class,
 880                 priv_query_executor, object, params, method_data, result);
 881 }
 882
 883 static
 884 bt_component_class_message_iterator_init_method_status
 885 component_class_message_iterator_init(
 886                 bt_self_message_iterator *self_message_iterator,
 887                 bt_self_component *self_component,
 888                 bt_self_component_port_output *self_component_port_output)
 889 {
 890         bt_component_class_message_iterator_init_method_status status = __BT_FUNC_STATUS_OK;
 891         PyObject *py_comp_cls = NULL;
 892         PyObject *py_iter_cls = NULL;
 893         PyObject *py_iter_ptr = NULL;
 894         PyObject *py_component_port_output_ptr = NULL;
 895         PyObject *py_init_method_result = NULL;
 896         PyObject *py_iter = NULL;
 897         PyObject *py_comp;
 898         bt_logging_level log_level = get_self_component_log_level(
 899                 self_component);
 900
 901         py_comp = bt_self_component_get_data(self_component);
 902
 903         /* Find user's Python message iterator class */
 904         py_comp_cls = PyObject_GetAttrString(py_comp, "__class__");
 905         if (!py_comp_cls) {
 906                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 907                         "Cannot get Python object's `__class__` attribute.");
 908                 goto python_error;
 909         }
 910
 911         py_iter_cls = PyObject_GetAttrString(py_comp_cls, "_iter_cls");
 912         if (!py_iter_cls) {
 913                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 914                         "Cannot get Python class's `_iter_cls` attribute.");
 915                 goto python_error;
 916         }
 917
 918         py_iter_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_message_iterator),
 919                 SWIGTYPE_p_bt_self_message_iterator, 0);
 920         if (!py_iter_ptr) {
 921                 const char *err = "Failed to create a SWIG pointer object.";
 922
 923                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 924                         "%s", err);
 925                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
 926                         self_message_iterator, err);
 927                 goto error;
 928         }
 929
 930         /*
 931          * Create object with borrowed native message iterator
 932          * reference:
 933          *
 934          *     py_iter = py_iter_cls.__new__(py_iter_cls, py_iter_ptr)
 935          */
 936         py_iter = PyObject_CallMethod(py_iter_cls, "__new__",
 937                 "(OO)", py_iter_cls, py_iter_ptr);
 938         if (!py_iter) {
 939                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 940                         "Failed to call Python class's __new__() method: "
 941                         "py-cls-addr=%p", py_iter_cls);
 942                 goto python_error;
 943         }
 944
 945         /*
 946          * Initialize object:
 947          *
 948          *     py_iter.__init__(self_output_port)
 949          *
 950          * through the _init_for_native helper static method.
 951          *
 952          * At this point, py_iter._ptr is set, so this initialization
 953          * function has access to self._component (which gives it the
 954          * user Python component object from which the iterator was
 955          * created).
 956          */
 957         py_component_port_output_ptr = SWIG_NewPointerObj(
 958                 SWIG_as_voidptr(self_component_port_output),
 959                 SWIGTYPE_p_bt_self_component_port_output, 0);
 960         if (!py_component_port_output_ptr) {
 961                 const char *err = "Failed to create a SWIG pointer object.";
 962
 963                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 964                         "%s", err);
 965                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
 966                         self_message_iterator, err);
 967                 goto error;
 968         }
 969
 970         py_init_method_result = PyObject_CallMethod(py_iter,
 971                 "_bt_init_from_native", "O", py_component_port_output_ptr);
 972         if (!py_init_method_result) {
 973                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 974                         "User's __init__() method failed:");
 975                 goto python_error;
 976         }
 977
 978         /*
 979          * Since the Python code can never instantiate a user-defined
 980          * message iterator class, the native message iterator
 981          * object does NOT belong to a user Python message iterator
 982          * object (borrowed reference). However this Python object is
 983          * owned by this native message iterator object.
 984          *
 985          * In the Python world, the lifetime of the native message
 986          * iterator is managed by a _GenericMessageIterator
 987          * instance:
 988          *
 989          *     _GenericMessageIterator instance:
 990          *         owns a native bt_message_iterator object (iter)
 991          *             owns a _UserMessageIterator instance (py_iter)
 992          *                 self._ptr is a borrowed reference to the
 993          *                 native bt_private_connection_private_message_iterator
 994          *                 object (iter)
 995          */
 996         bt_self_message_iterator_set_data(self_message_iterator, py_iter);
 997         py_iter = NULL;
 998         goto end;
 999
1000 python_error:
1001         /* Handling of errors that cause a Python exception to be set. */
1002         status = py_exc_to_status_message_iterator(self_message_iterator);
1003         BT_ASSERT(status != __BT_FUNC_STATUS_OK);
1004         goto end;
1005
1006 error:
1007         /* Handling of errors that don't cause a Python exception to be set. */
1008         status = __BT_FUNC_STATUS_ERROR;
1009
1010 end:
1011         BT_ASSERT(!PyErr_Occurred());
1012
1013         Py_XDECREF(py_comp_cls);
1014         Py_XDECREF(py_iter_cls);
1015         Py_XDECREF(py_iter_ptr);
1016         Py_XDECREF(py_component_port_output_ptr);
1017         Py_XDECREF(py_init_method_result);
1018         Py_XDECREF(py_iter);
1019         return status;
1020 }
1021
1022 static
1023 bt_component_class_message_iterator_init_method_status
1024 component_class_source_message_iterator_init(
1025                 bt_self_message_iterator *self_message_iterator,
1026                 bt_self_component_source *self_component_source,
1027                 bt_self_component_port_output *self_component_port_output)
1028 {
1029         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
1030
1031         return component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
1032 }
1033
1034 static
1035 bt_component_class_message_iterator_init_method_status
1036 component_class_filter_message_iterator_init(
1037                 bt_self_message_iterator *self_message_iterator,
1038                 bt_self_component_filter *self_component_filter,
1039                 bt_self_component_port_output *self_component_port_output)
1040 {
1041         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
1042
1043         return component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
1044 }
1045
1046 static
1047 void component_class_message_iterator_finalize(
1048                 bt_self_message_iterator *message_iterator)
1049 {
1050         PyObject *py_message_iter = bt_self_message_iterator_get_data(
1051                 message_iterator);
1052         PyObject *py_method_result = NULL;
1053
1054         BT_ASSERT(py_message_iter);
1055
1056         /* Call user's _user_finalize() method */
1057         py_method_result = PyObject_CallMethod(py_message_iter,
1058                 "_user_finalize", NULL);
1059
1060         if (PyErr_Occurred()) {
1061                 bt_self_component *self_comp =
1062                         bt_self_message_iterator_borrow_component(
1063                                 message_iterator);
1064                 bt_logging_level log_level = get_self_component_log_level(
1065                         self_comp);
1066
1067                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_comp,
1068                         "User's _user_finalize() method raised an exception: ignoring:");
1069                 logw_exception(get_self_message_iterator_log_level(
1070                         message_iterator));
1071         }
1072
1073         /*
1074          * Ignore any exception raised by the _user_finalize() method
1075          * because it won't change anything at this point: the component
1076          * is being destroyed anyway.
1077          */
1078         PyErr_Clear();
1079         Py_XDECREF(py_method_result);
1080         Py_DECREF(py_message_iter);
1081 }
1082
1083 /* Valid for both sources and filters. */
1084
1085 static
1086 bt_component_class_message_iterator_next_method_status
1087 component_class_message_iterator_next(
1088                 bt_self_message_iterator *message_iterator,
1089                 bt_message_array_const msgs, uint64_t capacity,
1090                 uint64_t *count)
1091 {
1092         bt_component_class_message_iterator_next_method_status status = __BT_FUNC_STATUS_OK;
1093         PyObject *py_message_iter = bt_self_message_iterator_get_data(message_iterator);
1094         PyObject *py_method_result = NULL;
1095
1096         BT_ASSERT(py_message_iter);
1097         py_method_result = PyObject_CallMethod(py_message_iter,
1098                 "_bt_next_from_native", NULL);
1099         if (!py_method_result) {
1100                 status = py_exc_to_status_message_iterator(message_iterator);
1101                 BT_ASSERT(status != __BT_FUNC_STATUS_OK);
1102                 goto end;
1103         }
1104
1105         /*
1106          * The returned object, on success, is an integer object
1107          * (PyLong) containing the address of a native message
1108          * object (which is now ours).
1109          */
1110         msgs[0] = PyLong_AsVoidPtr(py_method_result);
1111         *count = 1;
1112
1113         /* Clear potential overflow error; should never happen */
1114         BT_ASSERT(!PyErr_Occurred());
1115         goto end;
1116
1117 end:
1118         Py_XDECREF(py_method_result);
1119         return status;
1120 }
1121
1122 static
1123 bt_component_class_sink_consume_method_status
1124 component_class_sink_consume(bt_self_component_sink *self_component_sink)
1125 {
1126         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
1127         PyObject *py_comp = bt_self_component_get_data(self_component);
1128         PyObject *py_method_result = NULL;
1129         bt_component_class_sink_consume_method_status status;
1130
1131         BT_ASSERT(py_comp);
1132         py_method_result = PyObject_CallMethod(py_comp,
1133                 "_user_consume", NULL);
1134         status = py_exc_to_status_component(self_component);
1135         BT_ASSERT(py_method_result || status != __BT_FUNC_STATUS_OK);
1136         Py_XDECREF(py_method_result);
1137         return status;
1138 }
1139
1140 static
1141 int component_class_set_help_and_desc(
1142                 bt_component_class *component_class,
1143                 const char *description, const char *help)
1144 {
1145         int ret;
1146
1147         if (description) {
1148                 ret = bt_component_class_set_description(component_class, description);
1149                 if (ret) {
1150                         BT_LOGE("Cannot set component class's description: "
1151                                 "comp-cls-addr=%p", component_class);
1152                         goto end;
1153                 }
1154         }
1155
1156         if (help) {
1157                 ret = bt_component_class_set_help(component_class, help);
1158                 if (ret) {
1159                         BT_LOGE("Cannot set component class's help text: "
1160                                 "comp-cls-addr=%p", component_class);
1161                         goto end;
1162                 }
1163         }
1164
1165         ret = 0;
1166
1167 end:
1168         return ret;
1169 }
1170
1171 static
1172 bt_component_class_source *bt_bt2_component_class_source_create(
1173                 PyObject *py_cls, const char *name, const char *description,
1174                 const char *help)
1175 {
1176         bt_component_class_source *component_class_source;
1177         bt_component_class *component_class;
1178         int ret;
1179
1180         BT_ASSERT(py_cls);
1181         component_class_source = bt_component_class_source_create(name,
1182                 component_class_message_iterator_next);
1183         if (!component_class_source) {
1184                 BT_LOGE_STR("Cannot create source component class.");
1185                 goto end;
1186         }
1187
1188         component_class = bt_component_class_source_as_component_class(component_class_source);
1189
1190         if (component_class_set_help_and_desc(component_class, description, help)) {
1191                 goto end;
1192         }
1193
1194         ret = bt_component_class_source_set_init_method(component_class_source, component_class_source_init);
1195         BT_ASSERT(ret == 0);
1196         ret = bt_component_class_source_set_finalize_method(component_class_source, component_class_source_finalize);
1197         BT_ASSERT(ret == 0);
1198         ret = bt_component_class_source_set_message_iterator_can_seek_beginning_method(component_class_source,
1199                 component_class_can_seek_beginning);
1200         BT_ASSERT(ret == 0);
1201         ret = bt_component_class_source_set_message_iterator_seek_beginning_method(component_class_source,
1202                 component_class_seek_beginning);
1203         BT_ASSERT(ret == 0);
1204         ret = bt_component_class_source_set_output_port_connected_method(component_class_source,
1205                 component_class_source_output_port_connected);
1206         BT_ASSERT(ret == 0);
1207         ret = bt_component_class_source_set_query_method(component_class_source, component_class_source_query);
1208         BT_ASSERT(ret == 0);
1209         ret = bt_component_class_source_set_get_supported_mip_versions_method(component_class_source, component_class_source_get_supported_mip_versions);
1210         BT_ASSERT(ret == 0);
1211         ret = bt_component_class_source_set_message_iterator_init_method(
1212                 component_class_source, component_class_source_message_iterator_init);
1213         BT_ASSERT(ret == 0);
1214         ret = bt_component_class_source_set_message_iterator_finalize_method(
1215                 component_class_source, component_class_message_iterator_finalize);
1216         BT_ASSERT(ret == 0);
1217         register_cc_ptr_to_py_cls(component_class, py_cls);
1218
1219 end:
1220         return component_class_source;
1221 }
1222
1223 static
1224 bt_component_class_filter *bt_bt2_component_class_filter_create(
1225                 PyObject *py_cls, const char *name, const char *description,
1226                 const char *help)
1227 {
1228         bt_component_class *component_class;
1229         bt_component_class_filter *component_class_filter;
1230         int ret;
1231
1232         BT_ASSERT(py_cls);
1233         component_class_filter = bt_component_class_filter_create(name,
1234                 component_class_message_iterator_next);
1235         if (!component_class_filter) {
1236                 BT_LOGE_STR("Cannot create filter component class.");
1237                 goto end;
1238         }
1239
1240         component_class = bt_component_class_filter_as_component_class(component_class_filter);
1241
1242         if (component_class_set_help_and_desc(component_class, description, help)) {
1243                 goto end;
1244         }
1245
1246         ret = bt_component_class_filter_set_init_method(component_class_filter, component_class_filter_init);
1247         BT_ASSERT(ret == 0);
1248         ret = bt_component_class_filter_set_finalize_method (component_class_filter, component_class_filter_finalize);
1249         BT_ASSERT(ret == 0);
1250         ret = bt_component_class_filter_set_message_iterator_can_seek_beginning_method(component_class_filter,
1251                 component_class_can_seek_beginning);
1252         BT_ASSERT(ret == 0);
1253         ret = bt_component_class_filter_set_message_iterator_seek_beginning_method(component_class_filter,
1254                 component_class_seek_beginning);
1255         BT_ASSERT(ret == 0);
1256         ret = bt_component_class_filter_set_input_port_connected_method(component_class_filter,
1257                 component_class_filter_input_port_connected);
1258         BT_ASSERT(ret == 0);
1259         ret = bt_component_class_filter_set_output_port_connected_method(component_class_filter,
1260                 component_class_filter_output_port_connected);
1261         BT_ASSERT(ret == 0);
1262         ret = bt_component_class_filter_set_query_method(component_class_filter, component_class_filter_query);
1263         BT_ASSERT(ret == 0);
1264         ret = bt_component_class_filter_set_get_supported_mip_versions_method(component_class_filter, component_class_filter_get_supported_mip_versions);
1265         BT_ASSERT(ret == 0);
1266         ret = bt_component_class_filter_set_message_iterator_init_method(
1267                 component_class_filter, component_class_filter_message_iterator_init);
1268         BT_ASSERT(ret == 0);
1269         ret = bt_component_class_filter_set_message_iterator_finalize_method(
1270                 component_class_filter, component_class_message_iterator_finalize);
1271         BT_ASSERT(ret == 0);
1272         register_cc_ptr_to_py_cls(component_class, py_cls);
1273
1274 end:
1275         return component_class_filter;
1276 }
1277
1278 static
1279 bt_component_class_sink *bt_bt2_component_class_sink_create(
1280                 PyObject *py_cls, const char *name, const char *description,
1281                 const char *help)
1282 {
1283         bt_component_class_sink *component_class_sink;
1284         bt_component_class *component_class;
1285         int ret;
1286
1287         BT_ASSERT(py_cls);
1288         component_class_sink = bt_component_class_sink_create(name, component_class_sink_consume);
1289
1290         if (!component_class_sink) {
1291                 BT_LOGE_STR("Cannot create sink component class.");
1292                 goto end;
1293         }
1294
1295         component_class = bt_component_class_sink_as_component_class(component_class_sink);
1296
1297         if (component_class_set_help_and_desc(component_class, description, help)) {
1298                 goto end;
1299         }
1300
1301         ret = bt_component_class_sink_set_init_method(component_class_sink, component_class_sink_init);
1302         BT_ASSERT(ret == 0);
1303         ret = bt_component_class_sink_set_finalize_method(component_class_sink, component_class_sink_finalize);
1304         BT_ASSERT(ret == 0);
1305         ret = bt_component_class_sink_set_input_port_connected_method(component_class_sink,
1306                 component_class_sink_input_port_connected);
1307         BT_ASSERT(ret == 0);
1308         ret = bt_component_class_sink_set_graph_is_configured_method(component_class_sink,
1309                 component_class_sink_graph_is_configured);
1310         BT_ASSERT(ret == 0);
1311         ret = bt_component_class_sink_set_query_method(component_class_sink, component_class_sink_query);
1312         BT_ASSERT(ret == 0);
1313         ret = bt_component_class_sink_set_get_supported_mip_versions_method(component_class_sink, component_class_sink_get_supported_mip_versions);
1314         BT_ASSERT(ret == 0);
1315         register_cc_ptr_to_py_cls(component_class, py_cls);
1316
1317 end:
1318         return component_class_sink;
1319 }