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          * If there's any `init_method_data`, assume this component is
 219          * getting initialized from Python, so that `init_method_data`
 220          * is a Python object to pass to the user's __init__() method.
 221          */
 222         BT_ASSERT(!init_method_data ||
 223                         bt_bt2_is_python_component_class(component_class));
 224
 225         /*
 226          * Get the user-defined Python class which created this
 227          * component's class in the first place (borrowed
 228          * reference).
 229          */
 230         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 231         if (!py_cls) {
 232                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 233                         "Cannot find Python class associated to native component class: "
 234                         "comp-cls-addr=%p", component_class);
 235                 goto error;
 236         }
 237
 238         /* Parameters pointer -> SWIG pointer Python object */
 239         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 240                 SWIGTYPE_p_bt_value, 0);
 241         if (!py_params_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         py_comp_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_v),
 248                 self_comp_cls_type_swig_type, 0);
 249         if (!py_comp_ptr) {
 250                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 251                         "Failed to create a SWIG pointer object.");
 252                 goto error;
 253         }
 254
 255         /*
 256          * Do the equivalent of this:
 257          *
 258          *     py_comp = py_cls._bt_init_from_native(py_comp_ptr,
 259          *         py_params_ptr, init_method_data ? init_method_data : Py_None)
 260          *
 261          * _UserComponentType._bt_init_from_native() calls the Python
 262          * component object's __init__() function.
 263          *
 264          * We don't take any reference on `init_method_data` which, if
 265          * not `NULL`, is assumed to be a `PyObject *`: the user's
 266          * __init__() function will eventually take a reference if
 267          * needed. If `init_method_data` is `NULL`, then we pass
 268          * `Py_None` as the initialization's Python object.
 269          */
 270         py_comp = PyObject_CallMethod(py_cls,
 271                 "_bt_init_from_native", "(OOO)", py_comp_ptr, py_params_ptr,
 272                 init_method_data ? init_method_data : Py_None);
 273         if (!py_comp) {
 274                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_component,
 275                         "Failed to call Python class's _bt_init_from_native() method: "
 276                         "py-cls-addr=%p", py_cls);
 277                 status = py_exc_to_status_component(self_component);
 278                 goto end;
 279         }
 280
 281         /*
 282          * Our user Python component object is now fully created and
 283          * initialized by the user. Since we just created it, this
 284          * native component is its only (persistent) owner.
 285          */
 286         bt_self_component_set_data(self_component, py_comp);
 287         py_comp = NULL;
 288         goto end;
 289
 290 error:
 291         status = __BT_FUNC_STATUS_ERROR;
 292
 293         /*
 294          * Clear any exception: we're returning a bad status anyway. If
 295          * this call originated from Python (creation from a plugin's
 296          * component class, for example), then the user gets an
 297          * appropriate creation error.
 298          */
 299         PyErr_Clear();
 300
 301 end:
 302         Py_XDECREF(py_comp);
 303         Py_XDECREF(py_params_ptr);
 304         Py_XDECREF(py_comp_ptr);
 305         return status;
 306 }
 307
 308 /*
 309  * Method of bt_component_class_source to initialize a bt_self_component_source
 310  * of that class.
 311  */
 312
 313 static
 314 bt_component_class_init_method_status component_class_source_init(
 315                 bt_self_component_source *self_component_source,
 316                 const bt_value *params, void *init_method_data)
 317 {
 318         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 319         return component_class_init(
 320                 self_component,
 321                 self_component_source,
 322                 SWIGTYPE_p_bt_self_component_source,
 323                 params, init_method_data);
 324 }
 325
 326 static
 327 bt_component_class_init_method_status component_class_filter_init(
 328                 bt_self_component_filter *self_component_filter,
 329                 const bt_value *params, void *init_method_data)
 330 {
 331         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 332         return component_class_init(
 333                 self_component,
 334                 self_component_filter,
 335                 SWIGTYPE_p_bt_self_component_filter,
 336                 params, init_method_data);
 337 }
 338
 339 static
 340 bt_component_class_init_method_status component_class_sink_init(
 341                 bt_self_component_sink *self_component_sink,
 342                 const bt_value *params, void *init_method_data)
 343 {
 344         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 345         return component_class_init(
 346                 self_component,
 347                 self_component_sink,
 348                 SWIGTYPE_p_bt_self_component_sink,
 349                 params, init_method_data);
 350 }
 351
 352 static
 353 void component_class_finalize(bt_self_component *self_component)
 354 {
 355         PyObject *py_comp = bt_self_component_get_data(self_component);
 356         BT_ASSERT(py_comp);
 357
 358         /* Call user's _user_finalize() method */
 359         PyObject *py_method_result = PyObject_CallMethod(py_comp,
 360                 "_user_finalize", NULL);
 361
 362         if (PyErr_Occurred()) {
 363                 bt_logging_level log_level = get_self_component_log_level(
 364                         self_component);
 365
 366                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_component,
 367                         "User component's _user_finalize() method raised an exception: ignoring:");
 368                 logw_exception(log_level);
 369         }
 370
 371         /*
 372          * Ignore any exception raised by the _user_finalize() method
 373          * because it won't change anything at this point: the component
 374          * is being destroyed anyway.
 375          */
 376         PyErr_Clear();
 377         Py_XDECREF(py_method_result);
 378         Py_DECREF(py_comp);
 379 }
 380
 381 static
 382 void component_class_source_finalize(bt_self_component_source *self_component_source)
 383 {
 384         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 385         component_class_finalize(self_component);
 386 }
 387
 388 static
 389 void component_class_filter_finalize(bt_self_component_filter *self_component_filter)
 390 {
 391         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 392         component_class_finalize(self_component);
 393 }
 394
 395 static
 396 void component_class_sink_finalize(bt_self_component_sink *self_component_sink)
 397 {
 398         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 399         component_class_finalize(self_component);
 400 }
 401
 402 static
 403 bt_bool component_class_can_seek_beginning(
 404                 bt_self_message_iterator *self_message_iterator)
 405 {
 406         PyObject *py_iter;
 407         PyObject *py_result = NULL;
 408         bt_bool can_seek_beginning = false;
 409
 410         py_iter = bt_self_message_iterator_get_data(self_message_iterator);
 411         BT_ASSERT(py_iter);
 412
 413         py_result = PyObject_GetAttrString(py_iter, "_bt_can_seek_beginning_from_native");
 414
 415         BT_ASSERT(!py_result || PyBool_Check(py_result));
 416
 417         if (py_result) {
 418                 can_seek_beginning = PyObject_IsTrue(py_result);
 419         } else {
 420                 /*
 421                  * Once can_seek_beginning can report errors, convert the
 422                  * exception to a status.  For now, log and return false;
 423                  */
 424                 loge_exception_message_iterator(self_message_iterator);
 425                 PyErr_Clear();
 426         }
 427
 428         Py_XDECREF(py_result);
 429
 430         return can_seek_beginning;
 431 }
 432
 433 static
 434 bt_component_class_message_iterator_seek_beginning_method_status
 435 component_class_seek_beginning(bt_self_message_iterator *self_message_iterator)
 436 {
 437         PyObject *py_iter;
 438         PyObject *py_result;
 439         bt_component_class_message_iterator_seek_beginning_method_status status;
 440
 441         py_iter = bt_self_message_iterator_get_data(self_message_iterator);
 442         BT_ASSERT(py_iter);
 443         py_result = PyObject_CallMethod(py_iter, "_bt_seek_beginning_from_native",
 444                 NULL);
 445         BT_ASSERT(!py_result || py_result == Py_None);
 446         status = py_exc_to_status_message_iterator(self_message_iterator);
 447         Py_XDECREF(py_result);
 448         return status;
 449 }
 450
 451 static
 452 bt_component_class_port_connected_method_status component_class_port_connected(
 453                 bt_self_component *self_component,
 454                 void *self_component_port,
 455                 swig_type_info *self_component_port_swig_type,
 456                 bt_port_type self_component_port_type,
 457                 const void *other_port,
 458                 swig_type_info *other_port_swig_type)
 459 {
 460         bt_component_class_port_connected_method_status status;
 461         PyObject *py_comp = NULL;
 462         PyObject *py_self_port_ptr = NULL;
 463         PyObject *py_other_port_ptr = NULL;
 464         PyObject *py_method_result = NULL;
 465         bt_logging_level log_level = get_self_component_log_level(
 466                 self_component);
 467
 468         py_comp = bt_self_component_get_data(self_component);
 469         BT_ASSERT(py_comp);
 470         py_self_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_port),
 471                 self_component_port_swig_type, 0);
 472         if (!py_self_port_ptr) {
 473                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 474                         "Failed to create a SWIG pointer object.");
 475                 status = __BT_FUNC_STATUS_MEMORY_ERROR;
 476                 goto end;
 477         }
 478
 479         py_other_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(other_port),
 480                 other_port_swig_type, 0);
 481         if (!py_other_port_ptr) {
 482                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 483                         "Failed to create a SWIG pointer object.");
 484                 status = __BT_FUNC_STATUS_MEMORY_ERROR;
 485                 goto end;       }
 486
 487         py_method_result = PyObject_CallMethod(py_comp,
 488                 "_bt_port_connected_from_native", "(OiO)", py_self_port_ptr,
 489                 self_component_port_type, py_other_port_ptr);
 490         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 491         status = py_exc_to_status_component(self_component);
 492
 493 end:
 494         Py_XDECREF(py_self_port_ptr);
 495         Py_XDECREF(py_other_port_ptr);
 496         Py_XDECREF(py_method_result);
 497         return status;
 498 }
 499
 500 static
 501 bt_component_class_port_connected_method_status
 502 component_class_source_output_port_connected(
 503                 bt_self_component_source *self_component_source,
 504                 bt_self_component_port_output *self_component_port_output,
 505                 const bt_port_input *other_port_input)
 506 {
 507         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 508
 509         return component_class_port_connected(
 510                 self_component,
 511                 self_component_port_output,
 512                 SWIGTYPE_p_bt_self_component_port_output,
 513                 BT_PORT_TYPE_OUTPUT,
 514                 other_port_input,
 515                 SWIGTYPE_p_bt_port_input);
 516 }
 517
 518 static
 519 bt_component_class_port_connected_method_status
 520 component_class_filter_input_port_connected(
 521                 bt_self_component_filter *self_component_filter,
 522                 bt_self_component_port_input *self_component_port_input,
 523                 const bt_port_output *other_port_output)
 524 {
 525         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 526
 527         return component_class_port_connected(
 528                 self_component,
 529                 self_component_port_input,
 530                 SWIGTYPE_p_bt_self_component_port_input,
 531                 BT_PORT_TYPE_INPUT,
 532                 other_port_output,
 533                 SWIGTYPE_p_bt_port_output);
 534 }
 535
 536 static
 537 bt_component_class_port_connected_method_status
 538 component_class_filter_output_port_connected(
 539                 bt_self_component_filter *self_component_filter,
 540                 bt_self_component_port_output *self_component_port_output,
 541                 const bt_port_input *other_port_input)
 542 {
 543         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 544
 545         return component_class_port_connected(
 546                 self_component,
 547                 self_component_port_output,
 548                 SWIGTYPE_p_bt_self_component_port_output,
 549                 BT_PORT_TYPE_OUTPUT,
 550                 other_port_input,
 551                 SWIGTYPE_p_bt_port_input);
 552 }
 553
 554 static
 555 bt_component_class_port_connected_method_status
 556 component_class_sink_input_port_connected(
 557                 bt_self_component_sink *self_component_sink,
 558                 bt_self_component_port_input *self_component_port_input,
 559                 const bt_port_output *other_port_output)
 560 {
 561         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 562
 563         return component_class_port_connected(
 564                 self_component,
 565                 self_component_port_input,
 566                 SWIGTYPE_p_bt_self_component_port_input,
 567                 BT_PORT_TYPE_INPUT,
 568                 other_port_output,
 569                 SWIGTYPE_p_bt_port_output);
 570 }
 571
 572 static
 573 bt_component_class_sink_graph_is_configured_method_status
 574 component_class_sink_graph_is_configured(
 575                 bt_self_component_sink *self_component_sink)
 576 {
 577         PyObject *py_comp = NULL;
 578         PyObject *py_method_result = NULL;
 579         bt_component_class_sink_graph_is_configured_method_status status = __BT_FUNC_STATUS_OK;
 580         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 581
 582         py_comp = bt_self_component_get_data(self_component);
 583         py_method_result = PyObject_CallMethod(py_comp,
 584                 "_bt_graph_is_configured_from_native", NULL);
 585         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 586         status = py_exc_to_status_component(self_component);
 587         Py_XDECREF(py_method_result);
 588         return status;
 589 }
 590
 591 static
 592 bt_component_class_query_method_status component_class_query(
 593                 const bt_component_class *component_class,
 594                 bt_self_component_class *self_component_class,
 595                 bt_private_query_executor *priv_query_executor,
 596                 const char *object, const bt_value *params,
 597                 const bt_value **result)
 598 {
 599         PyObject *py_cls = NULL;
 600         PyObject *py_params_ptr = NULL;
 601         PyObject *py_priv_query_exec_ptr = NULL;
 602         PyObject *py_query_func = NULL;
 603         PyObject *py_object = NULL;
 604         PyObject *py_results_addr = NULL;
 605         bt_component_class_query_method_status status = __BT_FUNC_STATUS_OK;
 606         const bt_query_executor *query_exec =
 607                 bt_private_query_executor_as_query_executor_const(
 608                         priv_query_executor);
 609         bt_logging_level log_level =
 610                 bt_query_executor_get_logging_level(query_exec);
 611
 612         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 613         if (!py_cls) {
 614                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 615                         "Cannot find Python class associated to native component class: "
 616                         "comp-cls-addr=%p", component_class);
 617                 goto error;
 618         }
 619
 620         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 621                 SWIGTYPE_p_bt_value, 0);
 622         if (!py_params_ptr) {
 623                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 624                         "Failed to create a SWIG pointer object.");
 625                 goto error;
 626         }
 627
 628         py_priv_query_exec_ptr = SWIG_NewPointerObj(
 629                 SWIG_as_voidptr(priv_query_executor),
 630                 SWIGTYPE_p_bt_private_query_executor, 0);
 631         if (!py_priv_query_exec_ptr) {
 632                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 633                         "Failed to create a SWIG pointer object.");
 634                 goto error;
 635         }
 636
 637         py_object = SWIG_FromCharPtr(object);
 638         if (!py_object) {
 639                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 640                         "Failed to create a Python string.");
 641                 goto error;
 642         }
 643
 644         py_results_addr = PyObject_CallMethod(py_cls,
 645                 "_bt_query_from_native", "(OOO)", py_priv_query_exec_ptr,
 646                 py_object, py_params_ptr);
 647         if (!py_results_addr) {
 648                 BT_LOG_WRITE_CUR_LVL(BT_LOG_WARNING, log_level, BT_LOG_TAG,
 649                         "Failed to call Python class's _bt_query_from_native() method: "
 650                         "py-cls-addr=%p", py_cls);
 651                 status = py_exc_to_status_component_class(self_component_class,
 652                         log_level);
 653                 goto end;
 654         }
 655
 656         /*
 657          * The returned object, on success, is an integer object
 658          * (PyLong) containing the address of a BT value object (new
 659          * reference).
 660          */
 661         *result = PyLong_AsVoidPtr(py_results_addr);
 662         BT_ASSERT(!PyErr_Occurred());
 663         BT_ASSERT(*result);
 664         goto end;
 665
 666 error:
 667         PyErr_Clear();
 668         status = __BT_FUNC_STATUS_ERROR;
 669
 670 end:
 671         Py_XDECREF(py_params_ptr);
 672         Py_XDECREF(py_priv_query_exec_ptr);
 673         Py_XDECREF(py_query_func);
 674         Py_XDECREF(py_object);
 675         Py_XDECREF(py_results_addr);
 676         return status;
 677 }
 678
 679 static
 680 bt_component_class_query_method_status component_class_source_query(
 681                 bt_self_component_class_source *self_component_class_source,
 682                 bt_private_query_executor *priv_query_executor,
 683                 const char *object, const bt_value *params,
 684                 const bt_value **result)
 685 {
 686         const bt_component_class_source *component_class_source = bt_self_component_class_source_as_component_class_source(self_component_class_source);
 687         const bt_component_class *component_class = bt_component_class_source_as_component_class_const(component_class_source);
 688         bt_self_component_class *self_component_class = bt_self_component_class_source_as_self_component_class(self_component_class_source);
 689
 690         return component_class_query(component_class, self_component_class,
 691                 priv_query_executor, object, params, result);
 692 }
 693
 694 static
 695 bt_component_class_query_method_status component_class_filter_query(
 696                 bt_self_component_class_filter *self_component_class_filter,
 697                 bt_private_query_executor *priv_query_executor,
 698                 const char *object, const bt_value *params,
 699                 const bt_value **result)
 700 {
 701         const bt_component_class_filter *component_class_filter = bt_self_component_class_filter_as_component_class_filter(self_component_class_filter);
 702         const bt_component_class *component_class = bt_component_class_filter_as_component_class_const(component_class_filter);
 703         bt_self_component_class *self_component_class = bt_self_component_class_filter_as_self_component_class(self_component_class_filter);
 704
 705         return component_class_query(component_class, self_component_class,
 706                 priv_query_executor, object, params, result);
 707 }
 708
 709 static
 710 bt_component_class_query_method_status component_class_sink_query(
 711                 bt_self_component_class_sink *self_component_class_sink,
 712                 bt_private_query_executor *priv_query_executor,
 713                 const char *object, const bt_value *params,
 714                 const bt_value **result)
 715 {
 716         const bt_component_class_sink *component_class_sink = bt_self_component_class_sink_as_component_class_sink(self_component_class_sink);
 717         const bt_component_class *component_class = bt_component_class_sink_as_component_class_const(component_class_sink);
 718         bt_self_component_class *self_component_class = bt_self_component_class_sink_as_self_component_class(self_component_class_sink);
 719
 720         return component_class_query(component_class, self_component_class,
 721                 priv_query_executor, object, params, result);
 722 }
 723
 724 static
 725 bt_component_class_message_iterator_init_method_status
 726 component_class_message_iterator_init(
 727                 bt_self_message_iterator *self_message_iterator,
 728                 bt_self_component *self_component,
 729                 bt_self_component_port_output *self_component_port_output)
 730 {
 731         bt_component_class_message_iterator_init_method_status status = __BT_FUNC_STATUS_OK;
 732         PyObject *py_comp_cls = NULL;
 733         PyObject *py_iter_cls = NULL;
 734         PyObject *py_iter_ptr = NULL;
 735         PyObject *py_component_port_output_ptr = NULL;
 736         PyObject *py_init_method_result = NULL;
 737         PyObject *py_iter = NULL;
 738         PyObject *py_comp;
 739         bt_logging_level log_level = get_self_component_log_level(
 740                 self_component);
 741
 742         py_comp = bt_self_component_get_data(self_component);
 743
 744         /* Find user's Python message iterator class */
 745         py_comp_cls = PyObject_GetAttrString(py_comp, "__class__");
 746         if (!py_comp_cls) {
 747                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 748                         "Cannot get Python object's `__class__` attribute.");
 749                 goto python_error;
 750         }
 751
 752         py_iter_cls = PyObject_GetAttrString(py_comp_cls, "_iter_cls");
 753         if (!py_iter_cls) {
 754                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 755                         "Cannot get Python class's `_iter_cls` attribute.");
 756                 goto python_error;
 757         }
 758
 759         py_iter_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_message_iterator),
 760                 SWIGTYPE_p_bt_self_message_iterator, 0);
 761         if (!py_iter_ptr) {
 762                 const char *err = "Failed to create a SWIG pointer object.";
 763
 764                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 765                         "%s", err);
 766                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
 767                         self_message_iterator, err);
 768                 goto error;
 769         }
 770
 771         /*
 772          * Create object with borrowed native message iterator
 773          * reference:
 774          *
 775          *     py_iter = py_iter_cls.__new__(py_iter_cls, py_iter_ptr)
 776          */
 777         py_iter = PyObject_CallMethod(py_iter_cls, "__new__",
 778                 "(OO)", py_iter_cls, py_iter_ptr);
 779         if (!py_iter) {
 780                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 781                         "Failed to call Python class's __new__() method: "
 782                         "py-cls-addr=%p", py_iter_cls);
 783                 goto python_error;
 784         }
 785
 786         /*
 787          * Initialize object:
 788          *
 789          *     py_iter.__init__(self_output_port)
 790          *
 791          * through the _init_for_native helper static method.
 792          *
 793          * At this point, py_iter._ptr is set, so this initialization
 794          * function has access to self._component (which gives it the
 795          * user Python component object from which the iterator was
 796          * created).
 797          */
 798         py_component_port_output_ptr = SWIG_NewPointerObj(
 799                 SWIG_as_voidptr(self_component_port_output),
 800                 SWIGTYPE_p_bt_self_component_port_output, 0);
 801         if (!py_component_port_output_ptr) {
 802                 const char *err = "Failed to create a SWIG pointer object.";
 803
 804                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 805                         "%s", err);
 806                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
 807                         self_message_iterator, err);
 808                 goto error;
 809         }
 810
 811         py_init_method_result = PyObject_CallMethod(py_iter,
 812                 "_bt_init_from_native", "O", py_component_port_output_ptr);
 813         if (!py_init_method_result) {
 814                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 815                         "User's __init__() method failed:");
 816                 goto python_error;
 817         }
 818
 819         /*
 820          * Since the Python code can never instantiate a user-defined
 821          * message iterator class, the native message iterator
 822          * object does NOT belong to a user Python message iterator
 823          * object (borrowed reference). However this Python object is
 824          * owned by this native message iterator object.
 825          *
 826          * In the Python world, the lifetime of the native message
 827          * iterator is managed by a _GenericMessageIterator
 828          * instance:
 829          *
 830          *     _GenericMessageIterator instance:
 831          *         owns a native bt_message_iterator object (iter)
 832          *             owns a _UserMessageIterator instance (py_iter)
 833          *                 self._ptr is a borrowed reference to the
 834          *                 native bt_private_connection_private_message_iterator
 835          *                 object (iter)
 836          */
 837         bt_self_message_iterator_set_data(self_message_iterator, py_iter);
 838         py_iter = NULL;
 839         goto end;
 840
 841 python_error:
 842         /* Handling of errors that cause a Python exception to be set. */
 843         status = py_exc_to_status_message_iterator(self_message_iterator);
 844         BT_ASSERT(status != __BT_FUNC_STATUS_OK);
 845         goto end;
 846
 847 error:
 848         /* Handling of errors that don't cause a Python exception to be set. */
 849         status = __BT_FUNC_STATUS_ERROR;
 850
 851 end:
 852         BT_ASSERT(!PyErr_Occurred());
 853
 854         Py_XDECREF(py_comp_cls);
 855         Py_XDECREF(py_iter_cls);
 856         Py_XDECREF(py_iter_ptr);
 857         Py_XDECREF(py_component_port_output_ptr);
 858         Py_XDECREF(py_init_method_result);
 859         Py_XDECREF(py_iter);
 860         return status;
 861 }
 862
 863 static
 864 bt_component_class_message_iterator_init_method_status
 865 component_class_source_message_iterator_init(
 866                 bt_self_message_iterator *self_message_iterator,
 867                 bt_self_component_source *self_component_source,
 868                 bt_self_component_port_output *self_component_port_output)
 869 {
 870         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 871
 872         return component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
 873 }
 874
 875 static
 876 bt_component_class_message_iterator_init_method_status
 877 component_class_filter_message_iterator_init(
 878                 bt_self_message_iterator *self_message_iterator,
 879                 bt_self_component_filter *self_component_filter,
 880                 bt_self_component_port_output *self_component_port_output)
 881 {
 882         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 883
 884         return component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
 885 }
 886
 887 static
 888 void component_class_message_iterator_finalize(
 889                 bt_self_message_iterator *message_iterator)
 890 {
 891         PyObject *py_message_iter = bt_self_message_iterator_get_data(
 892                 message_iterator);
 893         PyObject *py_method_result = NULL;
 894
 895         BT_ASSERT(py_message_iter);
 896
 897         /* Call user's _user_finalize() method */
 898         py_method_result = PyObject_CallMethod(py_message_iter,
 899                 "_user_finalize", NULL);
 900
 901         if (PyErr_Occurred()) {
 902                 bt_self_component *self_comp =
 903                         bt_self_message_iterator_borrow_component(
 904                                 message_iterator);
 905                 bt_logging_level log_level = get_self_component_log_level(
 906                         self_comp);
 907
 908                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_comp,
 909                         "User's _user_finalize() method raised an exception: ignoring:");
 910                 logw_exception(get_self_message_iterator_log_level(
 911                         message_iterator));
 912         }
 913
 914         /*
 915          * Ignore any exception raised by the _user_finalize() method
 916          * because it won't change anything at this point: the component
 917          * is being destroyed anyway.
 918          */
 919         PyErr_Clear();
 920         Py_XDECREF(py_method_result);
 921         Py_DECREF(py_message_iter);
 922 }
 923
 924 /* Valid for both sources and filters. */
 925
 926 static
 927 bt_component_class_message_iterator_next_method_status
 928 component_class_message_iterator_next(
 929                 bt_self_message_iterator *message_iterator,
 930                 bt_message_array_const msgs, uint64_t capacity,
 931                 uint64_t *count)
 932 {
 933         bt_component_class_message_iterator_next_method_status status = __BT_FUNC_STATUS_OK;
 934         PyObject *py_message_iter = bt_self_message_iterator_get_data(message_iterator);
 935         PyObject *py_method_result = NULL;
 936
 937         BT_ASSERT(py_message_iter);
 938         py_method_result = PyObject_CallMethod(py_message_iter,
 939                 "_bt_next_from_native", NULL);
 940         if (!py_method_result) {
 941                 status = py_exc_to_status_message_iterator(message_iterator);
 942                 BT_ASSERT(status != __BT_FUNC_STATUS_OK);
 943                 goto end;
 944         }
 945
 946         /*
 947          * The returned object, on success, is an integer object
 948          * (PyLong) containing the address of a native message
 949          * object (which is now ours).
 950          */
 951         msgs[0] = PyLong_AsVoidPtr(py_method_result);
 952         *count = 1;
 953
 954         /* Clear potential overflow error; should never happen */
 955         BT_ASSERT(!PyErr_Occurred());
 956         goto end;
 957
 958 end:
 959         Py_XDECREF(py_method_result);
 960         return status;
 961 }
 962
 963 static
 964 bt_component_class_sink_consume_method_status
 965 component_class_sink_consume(bt_self_component_sink *self_component_sink)
 966 {
 967         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 968         PyObject *py_comp = bt_self_component_get_data(self_component);
 969         PyObject *py_method_result = NULL;
 970         bt_component_class_sink_consume_method_status status;
 971
 972         BT_ASSERT(py_comp);
 973         py_method_result = PyObject_CallMethod(py_comp,
 974                 "_user_consume", NULL);
 975         status = py_exc_to_status_component(self_component);
 976         BT_ASSERT(py_method_result || status != __BT_FUNC_STATUS_OK);
 977         Py_XDECREF(py_method_result);
 978         return status;
 979 }
 980
 981 static
 982 int component_class_set_help_and_desc(
 983                 bt_component_class *component_class,
 984                 const char *description, const char *help)
 985 {
 986         int ret;
 987
 988         if (description) {
 989                 ret = bt_component_class_set_description(component_class, description);
 990                 if (ret) {
 991                         BT_LOGE("Cannot set component class's description: "
 992                                 "comp-cls-addr=%p", component_class);
 993                         goto end;
 994                 }
 995         }
 996
 997         if (help) {
 998                 ret = bt_component_class_set_help(component_class, help);
 999                 if (ret) {
1000                         BT_LOGE("Cannot set component class's help text: "
1001                                 "comp-cls-addr=%p", component_class);
1002                         goto end;
1003                 }
1004         }
1005
1006         ret = 0;
1007
1008 end:
1009         return ret;
1010 }
1011
1012 static
1013 bt_component_class_source *bt_bt2_component_class_source_create(
1014                 PyObject *py_cls, const char *name, const char *description,
1015                 const char *help)
1016 {
1017         bt_component_class_source *component_class_source;
1018         bt_component_class *component_class;
1019         int ret;
1020
1021         BT_ASSERT(py_cls);
1022         component_class_source = bt_component_class_source_create(name,
1023                 component_class_message_iterator_next);
1024         if (!component_class_source) {
1025                 BT_LOGE_STR("Cannot create source component class.");
1026                 goto end;
1027         }
1028
1029         component_class = bt_component_class_source_as_component_class(component_class_source);
1030
1031         if (component_class_set_help_and_desc(component_class, description, help)) {
1032                 goto end;
1033         }
1034
1035         ret = bt_component_class_source_set_init_method(component_class_source, component_class_source_init);
1036         BT_ASSERT(ret == 0);
1037         ret = bt_component_class_source_set_finalize_method(component_class_source, component_class_source_finalize);
1038         BT_ASSERT(ret == 0);
1039         ret = bt_component_class_source_set_message_iterator_can_seek_beginning_method(component_class_source,
1040                 component_class_can_seek_beginning);
1041         BT_ASSERT(ret == 0);
1042         ret = bt_component_class_source_set_message_iterator_seek_beginning_method(component_class_source,
1043                 component_class_seek_beginning);
1044         BT_ASSERT(ret == 0);
1045         ret = bt_component_class_source_set_output_port_connected_method(component_class_source,
1046                 component_class_source_output_port_connected);
1047         BT_ASSERT(ret == 0);
1048         ret = bt_component_class_source_set_query_method(component_class_source, component_class_source_query);
1049         BT_ASSERT(ret == 0);
1050         ret = bt_component_class_source_set_message_iterator_init_method(
1051                 component_class_source, component_class_source_message_iterator_init);
1052         BT_ASSERT(ret == 0);
1053         ret = bt_component_class_source_set_message_iterator_finalize_method(
1054                 component_class_source, component_class_message_iterator_finalize);
1055         BT_ASSERT(ret == 0);
1056         register_cc_ptr_to_py_cls(component_class, py_cls);
1057
1058 end:
1059         return component_class_source;
1060 }
1061
1062 static
1063 bt_component_class_filter *bt_bt2_component_class_filter_create(
1064                 PyObject *py_cls, const char *name, const char *description,
1065                 const char *help)
1066 {
1067         bt_component_class *component_class;
1068         bt_component_class_filter *component_class_filter;
1069         int ret;
1070
1071         BT_ASSERT(py_cls);
1072         component_class_filter = bt_component_class_filter_create(name,
1073                 component_class_message_iterator_next);
1074         if (!component_class_filter) {
1075                 BT_LOGE_STR("Cannot create filter component class.");
1076                 goto end;
1077         }
1078
1079         component_class = bt_component_class_filter_as_component_class(component_class_filter);
1080
1081         if (component_class_set_help_and_desc(component_class, description, help)) {
1082                 goto end;
1083         }
1084
1085         ret = bt_component_class_filter_set_init_method(component_class_filter, component_class_filter_init);
1086         BT_ASSERT(ret == 0);
1087         ret = bt_component_class_filter_set_finalize_method (component_class_filter, component_class_filter_finalize);
1088         BT_ASSERT(ret == 0);
1089         ret = bt_component_class_filter_set_message_iterator_can_seek_beginning_method(component_class_filter,
1090                 component_class_can_seek_beginning);
1091         BT_ASSERT(ret == 0);
1092         ret = bt_component_class_filter_set_message_iterator_seek_beginning_method(component_class_filter,
1093                 component_class_seek_beginning);
1094         BT_ASSERT(ret == 0);
1095         ret = bt_component_class_filter_set_input_port_connected_method(component_class_filter,
1096                 component_class_filter_input_port_connected);
1097         BT_ASSERT(ret == 0);
1098         ret = bt_component_class_filter_set_output_port_connected_method(component_class_filter,
1099                 component_class_filter_output_port_connected);
1100         BT_ASSERT(ret == 0);
1101         ret = bt_component_class_filter_set_query_method(component_class_filter, component_class_filter_query);
1102         BT_ASSERT(ret == 0);
1103         ret = bt_component_class_filter_set_message_iterator_init_method(
1104                 component_class_filter, component_class_filter_message_iterator_init);
1105         BT_ASSERT(ret == 0);
1106         ret = bt_component_class_filter_set_message_iterator_finalize_method(
1107                 component_class_filter, component_class_message_iterator_finalize);
1108         BT_ASSERT(ret == 0);
1109         register_cc_ptr_to_py_cls(component_class, py_cls);
1110
1111 end:
1112         return component_class_filter;
1113 }
1114
1115 static
1116 bt_component_class_sink *bt_bt2_component_class_sink_create(
1117                 PyObject *py_cls, const char *name, const char *description,
1118                 const char *help)
1119 {
1120         bt_component_class_sink *component_class_sink;
1121         bt_component_class *component_class;
1122         int ret;
1123
1124         BT_ASSERT(py_cls);
1125         component_class_sink = bt_component_class_sink_create(name, component_class_sink_consume);
1126
1127         if (!component_class_sink) {
1128                 BT_LOGE_STR("Cannot create sink component class.");
1129                 goto end;
1130         }
1131
1132         component_class = bt_component_class_sink_as_component_class(component_class_sink);
1133
1134         if (component_class_set_help_and_desc(component_class, description, help)) {
1135                 goto end;
1136         }
1137
1138         ret = bt_component_class_sink_set_init_method(component_class_sink, component_class_sink_init);
1139         BT_ASSERT(ret == 0);
1140         ret = bt_component_class_sink_set_finalize_method(component_class_sink, component_class_sink_finalize);
1141         BT_ASSERT(ret == 0);
1142         ret = bt_component_class_sink_set_input_port_connected_method(component_class_sink,
1143                 component_class_sink_input_port_connected);
1144         BT_ASSERT(ret == 0);
1145         ret = bt_component_class_sink_set_graph_is_configured_method(component_class_sink,
1146                 component_class_sink_graph_is_configured);
1147         BT_ASSERT(ret == 0);
1148         ret = bt_component_class_sink_set_query_method(component_class_sink, component_class_sink_query);
1149         BT_ASSERT(ret == 0);
1150         register_cc_ptr_to_py_cls(component_class, py_cls);
1151
1152 end:
1153         return component_class_sink;
1154 }