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

   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 <babeltrace2/graph/component-class.h>
  26 %include <babeltrace2/graph/component-class-const.h>
  27 %include <babeltrace2/graph/component-class-source-const.h>
  28 %include <babeltrace2/graph/component-class-source.h>
  29 %include <babeltrace2/graph/component-class-filter-const.h>
  30 %include <babeltrace2/graph/component-class-filter.h>
  31 %include <babeltrace2/graph/component-class-sink-const.h>
  32 %include <babeltrace2/graph/component-class-sink.h>
  33 %include <babeltrace2/graph/self-component-class-source.h>
  34 %include <babeltrace2/graph/self-component-class-filter.h>
  35 %include <babeltrace2/graph/self-component-class-sink.h>
  36
  37 %{
  38 #include "logging/comp-logging.h"
  39
  40 /*
  41  * This hash table associates a BT component class object address to a
  42  * user-defined Python class (PyObject *). The keys and values are NOT
  43  * owned by this hash table. The Python class objects are owned by the
  44  * Python module, which should not be unloaded until it is not possible
  45  * to create a user Python component anyway.
  46  *
  47  * This hash table is written to when a user-defined Python component
  48  * class is created by one of the bt_bt2_component_class_*_create()
  49  * functions.
  50  *
  51  * This function is read from when a user calls bt_component_create()
  52  * with a component class pointer created by one of the functions above.
  53  * In this case, the original Python class needs to be found to
  54  * instantiate it and associate the created Python component object with
  55  * a BT component object instance.
  56  */
  57
  58 static GHashTable *bt_cc_ptr_to_py_cls;
  59
  60 static
  61 void register_cc_ptr_to_py_cls(struct bt_component_class *bt_cc,
  62                 PyObject *py_cls)
  63 {
  64         if (!bt_cc_ptr_to_py_cls) {
  65                 /*
  66                  * Lazy-initializing this GHashTable because GLib
  67                  * might not be initialized yet and it needs to be
  68                  * before we call g_hash_table_new()
  69                  */
  70                 BT_LOGD_STR("Creating native component class to Python component class hash table.");
  71                 bt_cc_ptr_to_py_cls = g_hash_table_new(g_direct_hash, g_direct_equal);
  72                 BT_ASSERT(bt_cc_ptr_to_py_cls);
  73         }
  74
  75         g_hash_table_insert(bt_cc_ptr_to_py_cls, (gpointer) bt_cc,
  76                 (gpointer) py_cls);
  77 }
  78
  79 static
  80 PyObject *lookup_cc_ptr_to_py_cls(const bt_component_class *bt_cc)
  81 {
  82         if (!bt_cc_ptr_to_py_cls) {
  83                 BT_LOGW("Cannot look up Python component class because hash table is NULL: "
  84                         "comp-cls-addr=%p", bt_cc);
  85                 return NULL;
  86         }
  87
  88         return (PyObject *) g_hash_table_lookup(bt_cc_ptr_to_py_cls,
  89                 (gconstpointer) bt_cc);
  90 }
  91
  92
  93 /*
  94  * Useful Python objects.
  95  */
  96
  97 static PyObject *py_mod_bt2 = NULL;
  98 static PyObject *py_mod_bt2_exc_error_type = NULL;
  99 static PyObject *py_mod_bt2_exc_memory_error = NULL;
 100 static PyObject *py_mod_bt2_exc_try_again_type = NULL;
 101 static PyObject *py_mod_bt2_exc_stop_type = NULL;
 102 static PyObject *py_mod_bt2_exc_unknown_object_type = NULL;
 103
 104 static
 105 void bt_bt2_cc_init_from_bt2(void)
 106 {
 107         /*
 108          * This is called once the bt2 package is loaded.
 109          *
 110          * Those modules and functions are needed while the package is
 111          * used. Loading them here is safe because we know the bt2
 112          * package is imported, and we know that the user cannot use the
 113          * code here without importing bt2 first.
 114          */
 115         py_mod_bt2 = PyImport_ImportModule("bt2");
 116         BT_ASSERT(py_mod_bt2);
 117         py_mod_bt2_exc_error_type =
 118                 PyObject_GetAttrString(py_mod_bt2, "_Error");
 119         BT_ASSERT(py_mod_bt2_exc_error_type);
 120         py_mod_bt2_exc_memory_error =
 121                 PyObject_GetAttrString(py_mod_bt2, "_MemoryError");
 122         BT_ASSERT(py_mod_bt2_exc_memory_error);
 123         py_mod_bt2_exc_try_again_type =
 124                 PyObject_GetAttrString(py_mod_bt2, "TryAgain");
 125         BT_ASSERT(py_mod_bt2_exc_try_again_type);
 126         py_mod_bt2_exc_stop_type =
 127                 PyObject_GetAttrString(py_mod_bt2, "Stop");
 128         BT_ASSERT(py_mod_bt2_exc_stop_type);
 129         py_mod_bt2_exc_unknown_object_type =
 130                 PyObject_GetAttrString(py_mod_bt2, "UnknownObject");
 131         BT_ASSERT(py_mod_bt2_exc_unknown_object_type);
 132 }
 133
 134 static
 135 void bt_bt2_cc_exit_handler(void)
 136 {
 137         /*
 138          * This is an exit handler (set by the bt2 package).
 139          *
 140          * We only give back the references that we took in
 141          * bt_bt2_cc_init_from_bt2() here. The global variables continue
 142          * to exist for the code of this file, but they are now borrowed
 143          * references. If this code is executed, it means that somehow
 144          * the modules are still loaded, so it should be safe to use
 145          * them even without a strong reference.
 146          *
 147          * We cannot do this in the library's destructor because it
 148          * gets executed once Python is already finalized.
 149          */
 150         Py_XDECREF(py_mod_bt2);
 151         Py_XDECREF(py_mod_bt2_exc_error_type);
 152         Py_XDECREF(py_mod_bt2_exc_try_again_type);
 153         Py_XDECREF(py_mod_bt2_exc_stop_type);
 154         Py_XDECREF(py_mod_bt2_exc_unknown_object_type);
 155 }
 156
 157
 158 /* Library destructor */
 159
 160 __attribute__((destructor))
 161 static
 162 void native_comp_class_dtor(void) {
 163         /* Destroy component class association hash table */
 164         if (bt_cc_ptr_to_py_cls) {
 165                 BT_LOGD_STR("Destroying native component class to Python component class hash table.");
 166                 g_hash_table_destroy(bt_cc_ptr_to_py_cls);
 167         }
 168 }
 169
 170 static
 171 void restore_current_thread_error_and_append_exception_chain_recursive(
 172                 int active_log_level, PyObject *py_exc_value,
 173                 bt_self_component_class *self_component_class,
 174                 bt_self_component *self_component,
 175                 bt_self_message_iterator *self_message_iterator,
 176                 const char *module_name)
 177 {
 178         PyObject *py_exc_cause_value;
 179         PyObject *py_exc_type = NULL;
 180         PyObject *py_exc_tb = NULL;
 181         GString *gstr = NULL;
 182
 183         /* If this exception has a cause, handle that one first. */
 184         py_exc_cause_value = PyException_GetCause(py_exc_value);
 185         if (py_exc_cause_value) {
 186                 restore_current_thread_error_and_append_exception_chain_recursive(
 187                         active_log_level, py_exc_cause_value,
 188                         self_component_class, self_component,
 189                         self_message_iterator, module_name);
 190         }
 191
 192         /*
 193          * If the raised exception is a bt2._Error, restore the wrapped error.
 194          */
 195         if (PyErr_GivenExceptionMatches(py_exc_value, py_mod_bt2_exc_error_type)) {
 196                 PyObject *py_error_swig_ptr;
 197                 const bt_error *error;
 198                 int ret;
 199
 200                 /*
 201                  * We never raise a bt2._Error with a cause: it should be the
 202                  * end of the chain.
 203                  */
 204                 BT_ASSERT(!py_exc_cause_value);
 205
 206                 /*
 207                  * We steal the error object from the exception, to move
 208                  * it back as the current thread's error.
 209                  */
 210                 py_error_swig_ptr = PyObject_GetAttrString(py_exc_value, "_ptr");
 211                 BT_ASSERT(py_error_swig_ptr);
 212
 213                 ret = PyObject_SetAttrString(py_exc_value, "_ptr", Py_None);
 214                 BT_ASSERT(ret == 0);
 215
 216                 ret = SWIG_ConvertPtr(py_error_swig_ptr, (void **) &error,
 217                         SWIGTYPE_p_bt_error, 0);
 218                 BT_ASSERT(ret == 0);
 219
 220                 BT_CURRENT_THREAD_MOVE_ERROR_AND_RESET(error);
 221
 222                 Py_DECREF(py_error_swig_ptr);
 223         }
 224
 225         py_exc_type = PyObject_Type(py_exc_value);
 226         py_exc_tb = PyException_GetTraceback(py_exc_value);
 227
 228         gstr = bt_py_common_format_exception(py_exc_type, py_exc_value,
 229                         py_exc_tb, active_log_level, false);
 230         if (!gstr) {
 231                 /* bt_py_common_format_exception has already warned. */
 232                 goto end;
 233         }
 234
 235         if (self_component_class) {
 236                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_COMPONENT_CLASS(
 237                         self_component_class, "%s", gstr->str);
 238         } else if (self_component) {
 239                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_COMPONENT(
 240                         self_component, "%s", gstr->str);
 241         } else if (self_message_iterator) {
 242                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
 243                         self_message_iterator, "%s", gstr->str);
 244         } else {
 245                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_UNKNOWN(
 246                         module_name, "%s", gstr->str);
 247         }
 248
 249 end:
 250         if (gstr) {
 251                 g_string_free(gstr, TRUE);
 252         }
 253
 254         Py_XDECREF(py_exc_cause_value);
 255         Py_XDECREF(py_exc_type);
 256         Py_XDECREF(py_exc_tb);
 257 }
 258
 259 /*
 260  * If you have the following code:
 261  *
 262  * try:
 263  *     try:
 264  *         something_that_raises_bt2_error()
 265  *     except bt2._Error as e1:
 266  *         raise ValueError from e1
 267  * except ValueError as e2:
 268  *     raise TypeError from e2
 269  *
 270  * We will have the following exception chain:
 271  *
 272  *     TypeError -> ValueError -> bt2._Error
 273  *
 274  * Where the TypeError is the current exception (obtained from PyErr_Fetch).
 275  *
 276  * The bt2._Error contains a `struct bt_error *` that used to be the current
 277  * thread's error, at the moment the exception was raised.
 278  *
 279  * This function gets to the bt2._Error and restores the wrapped
 280  * `struct bt_error *` as the current thread's error.
 281  *
 282  * Then, for each exception in the chain, starting with the oldest one, it adds
 283  * an error cause to the current thread's error.
 284  */
 285 static
 286 void restore_bt_error_and_append_current_exception_chain(
 287                 int active_log_level,
 288                 bt_self_component_class *self_component_class,
 289                 bt_self_component *self_component,
 290                 bt_self_message_iterator *self_message_iterator,
 291                 const char *module_name)
 292 {
 293         BT_ASSERT(PyErr_Occurred());
 294
 295         /* Used to access and restore the current exception. */
 296         PyObject *py_exc_type;
 297         PyObject *py_exc_value;
 298         PyObject *py_exc_tb;
 299
 300         /* Fetch and normalize the Python exception. */
 301         PyErr_Fetch(&py_exc_type, &py_exc_value, &py_exc_tb);
 302         PyErr_NormalizeException(&py_exc_type, &py_exc_value, &py_exc_tb);
 303         BT_ASSERT(py_exc_type);
 304         BT_ASSERT(py_exc_value);
 305         BT_ASSERT(py_exc_tb);
 306
 307         /*
 308          * Set the exception's traceback so it's possible to get it using
 309          * PyException_GetTraceback in
 310          * restore_current_thread_error_and_append_exception_chain_recursive.
 311          */
 312         PyException_SetTraceback(py_exc_value, py_exc_tb);
 313
 314         restore_current_thread_error_and_append_exception_chain_recursive(
 315                 active_log_level, py_exc_value, self_component_class,
 316                 self_component, self_message_iterator, module_name);
 317
 318         PyErr_Restore(py_exc_type, py_exc_value, py_exc_tb);
 319 }
 320
 321 static inline
 322 void log_exception_and_maybe_append_error(int func_log_level,
 323                 int active_log_level, bool append_error,
 324                 bt_self_component_class *self_component_class,
 325                 bt_self_component *self_component,
 326                 bt_self_message_iterator *self_message_iterator,
 327                 const char *module_name)
 328 {
 329         GString *gstr;
 330
 331         BT_ASSERT(PyErr_Occurred());
 332         gstr = bt_py_common_format_current_exception(active_log_level);
 333         if (!gstr) {
 334                 /* bt_py_common_format_current_exception() logs errors */
 335                 goto end;
 336         }
 337
 338         BT_COMP_LOG_CUR_LVL(func_log_level, active_log_level, self_component,
 339                 "%s", gstr->str);
 340
 341         if (append_error) {
 342                 restore_bt_error_and_append_current_exception_chain(
 343                         active_log_level, self_component_class, self_component,
 344                         self_message_iterator, module_name);
 345
 346         }
 347
 348 end:
 349         if (gstr) {
 350                 g_string_free(gstr, TRUE);
 351         }
 352 }
 353
 354 static
 355 bt_logging_level get_self_component_log_level(bt_self_component *self_comp)
 356 {
 357         return bt_component_get_logging_level(
 358                 bt_self_component_as_component(self_comp));
 359 }
 360
 361 static
 362 bt_logging_level get_self_message_iterator_log_level(
 363                 bt_self_message_iterator *self_msg_iter)
 364 {
 365         bt_self_component *self_comp =
 366                 bt_self_message_iterator_borrow_component(self_msg_iter);
 367
 368         return get_self_component_log_level(self_comp);
 369 }
 370
 371 static inline
 372 void loge_exception(const char *module_name, int active_log_level)
 373 {
 374         log_exception_and_maybe_append_error(BT_LOG_ERROR, active_log_level,
 375                 true, NULL, NULL, NULL, module_name);
 376 }
 377
 378 static
 379 void loge_exception_message_iterator(
 380                 bt_self_message_iterator *self_message_iterator)
 381 {
 382         bt_logging_level log_level = get_self_message_iterator_log_level(
 383                 self_message_iterator);
 384
 385         log_exception_and_maybe_append_error(BT_LOG_ERROR, log_level,
 386                 true, NULL, NULL, self_message_iterator, NULL);
 387 }
 388
 389 static inline
 390 void logw_exception(int active_log_level)
 391 {
 392         log_exception_and_maybe_append_error(BT_LOG_WARNING, active_log_level,
 393                 false, NULL, NULL, NULL, NULL);
 394 }
 395
 396 static inline
 397 int py_exc_to_status(bt_self_component_class *self_component_class,
 398                 bt_self_component *self_component,
 399                 bt_self_message_iterator *self_message_iterator,
 400                 const char *module_name, int active_log_level)
 401 {
 402         int status = __BT_FUNC_STATUS_OK;
 403         PyObject *exc = PyErr_Occurred();
 404
 405         if (!exc) {
 406                 goto end;
 407         }
 408
 409         if (PyErr_GivenExceptionMatches(exc,
 410                         py_mod_bt2_exc_try_again_type)) {
 411                 status = __BT_FUNC_STATUS_AGAIN;
 412         } else if (PyErr_GivenExceptionMatches(exc,
 413                         py_mod_bt2_exc_stop_type)) {
 414                 status = __BT_FUNC_STATUS_END;
 415         } else if (PyErr_GivenExceptionMatches(exc,
 416                         py_mod_bt2_exc_unknown_object_type)) {
 417                 status = __BT_FUNC_STATUS_UNKNOWN_OBJECT;
 418         } else {
 419                 /*
 420                  * Unknown exception: convert to general error.
 421                  *
 422                  * Because we only want to fetch the log level when
 423                  * we actually get an exception, and not systematically
 424                  * when we call py_exc_to_status() (as py_exc_to_status()
 425                  * can return `__BT_FUNC_STATUS_OK`), we get it here
 426                  * depending on the actor's type.
 427                  */
 428                 if (self_component) {
 429                         active_log_level = get_self_component_log_level(
 430                                 self_component);
 431                 } else if (self_message_iterator) {
 432                         active_log_level = get_self_message_iterator_log_level(
 433                                 self_message_iterator);
 434                 }
 435
 436                 BT_ASSERT(active_log_level != -1);
 437                 log_exception_and_maybe_append_error(BT_LOG_WARNING,
 438                         active_log_level, true,
 439                         self_component_class, self_component,
 440                         self_message_iterator, module_name);
 441
 442                 if (PyErr_GivenExceptionMatches(exc,
 443                                 py_mod_bt2_exc_memory_error)) {
 444                         status = __BT_FUNC_STATUS_MEMORY_ERROR;
 445                 } else {
 446                         status = __BT_FUNC_STATUS_ERROR;
 447                 }
 448         }
 449
 450 end:
 451         PyErr_Clear();
 452         return status;
 453 }
 454
 455 static
 456 int py_exc_to_status_component_class(
 457                 bt_self_component_class *self_component_class,
 458                 int active_log_level)
 459 {
 460         return py_exc_to_status(self_component_class, NULL, NULL, NULL,
 461                 active_log_level);
 462 }
 463
 464 static
 465 int py_exc_to_status_component(bt_self_component *self_component)
 466 {
 467         return py_exc_to_status(NULL, self_component, NULL, NULL, -1);
 468 }
 469
 470 static
 471 int py_exc_to_status_message_iterator(
 472                 bt_self_message_iterator *self_message_iterator)
 473 {
 474         return py_exc_to_status(NULL, NULL, self_message_iterator, NULL, -1);
 475 }
 476
 477 /* Component class proxy methods (delegate to the attached Python object) */
 478
 479 static
 480 bt_component_class_init_method_status component_class_init(
 481                 bt_self_component *self_component,
 482                 void *self_component_v,
 483                 swig_type_info *self_comp_cls_type_swig_type,
 484                 const bt_value *params,
 485                 void *init_method_data)
 486 {
 487         const bt_component *component = bt_self_component_as_component(self_component);
 488         const bt_component_class *component_class = bt_component_borrow_class_const(component);
 489         bt_component_class_init_method_status status = __BT_FUNC_STATUS_OK;
 490         PyObject *py_cls = NULL;
 491         PyObject *py_comp = NULL;
 492         PyObject *py_params_ptr = NULL;
 493         PyObject *py_comp_ptr = NULL;
 494         bt_logging_level log_level = get_self_component_log_level(
 495                 self_component);
 496
 497         (void) init_method_data;
 498
 499         BT_ASSERT(self_component);
 500         BT_ASSERT(self_component_v);
 501         BT_ASSERT(self_comp_cls_type_swig_type);
 502
 503         /*
 504          * Get the user-defined Python class which created this
 505          * component's class in the first place (borrowed
 506          * reference).
 507          */
 508         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 509         if (!py_cls) {
 510                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 511                         "Cannot find Python class associated to native component class: "
 512                         "comp-cls-addr=%p", component_class);
 513                 goto error;
 514         }
 515
 516         /* Parameters pointer -> SWIG pointer Python object */
 517         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 518                 SWIGTYPE_p_bt_value, 0);
 519         if (!py_params_ptr) {
 520                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 521                         "Failed to create a SWIG pointer object.");
 522                 goto error;
 523         }
 524
 525         py_comp_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_v),
 526                 self_comp_cls_type_swig_type, 0);
 527         if (!py_comp_ptr) {
 528                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 529                         "Failed to create a SWIG pointer object.");
 530                 goto error;
 531         }
 532
 533         /*
 534          * Do the equivalent of this:
 535          *
 536          *     py_comp = py_cls._bt_init_from_native(py_comp_ptr, py_params_ptr)
 537          *
 538          * _UserComponentType._bt_init_from_native() calls the Python
 539          * component object's __init__() function.
 540          */
 541         py_comp = PyObject_CallMethod(py_cls,
 542                 "_bt_init_from_native", "(OO)", py_comp_ptr, py_params_ptr);
 543         if (!py_comp) {
 544                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_component,
 545                         "Failed to call Python class's _bt_init_from_native() method: "
 546                         "py-cls-addr=%p", py_cls);
 547                 status = py_exc_to_status_component(self_component);
 548                 goto end;
 549         }
 550
 551         /*
 552          * Our user Python component object is now fully created and
 553          * initialized by the user. Since we just created it, this
 554          * native component is its only (persistent) owner.
 555          */
 556         bt_self_component_set_data(self_component, py_comp);
 557         py_comp = NULL;
 558         goto end;
 559
 560 error:
 561         status = __BT_FUNC_STATUS_ERROR;
 562
 563         /*
 564          * Clear any exception: we're returning a bad status anyway. If
 565          * this call originated from Python (creation from a plugin's
 566          * component class, for example), then the user gets an
 567          * appropriate creation error.
 568          */
 569         PyErr_Clear();
 570
 571 end:
 572         Py_XDECREF(py_comp);
 573         Py_XDECREF(py_params_ptr);
 574         Py_XDECREF(py_comp_ptr);
 575         return status;
 576 }
 577
 578 /*
 579  * Method of bt_component_class_source to initialize a bt_self_component_source
 580  * of that class.
 581  */
 582
 583 static
 584 bt_component_class_init_method_status component_class_source_init(
 585                 bt_self_component_source *self_component_source,
 586                 const bt_value *params, void *init_method_data)
 587 {
 588         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 589         return component_class_init(
 590                 self_component,
 591                 self_component_source,
 592                 SWIGTYPE_p_bt_self_component_source,
 593                 params, init_method_data);
 594 }
 595
 596 static
 597 bt_component_class_init_method_status component_class_filter_init(
 598                 bt_self_component_filter *self_component_filter,
 599                 const bt_value *params, void *init_method_data)
 600 {
 601         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 602         return component_class_init(
 603                 self_component,
 604                 self_component_filter,
 605                 SWIGTYPE_p_bt_self_component_filter,
 606                 params, init_method_data);
 607 }
 608
 609 static
 610 bt_component_class_init_method_status component_class_sink_init(
 611                 bt_self_component_sink *self_component_sink,
 612                 const bt_value *params, void *init_method_data)
 613 {
 614         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 615         return component_class_init(
 616                 self_component,
 617                 self_component_sink,
 618                 SWIGTYPE_p_bt_self_component_sink,
 619                 params, init_method_data);
 620 }
 621
 622 static
 623 void component_class_finalize(bt_self_component *self_component)
 624 {
 625         PyObject *py_comp = bt_self_component_get_data(self_component);
 626         BT_ASSERT(py_comp);
 627
 628         /* Call user's _user_finalize() method */
 629         PyObject *py_method_result = PyObject_CallMethod(py_comp,
 630                 "_user_finalize", NULL);
 631
 632         if (PyErr_Occurred()) {
 633                 bt_logging_level log_level = get_self_component_log_level(
 634                         self_component);
 635
 636                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_component,
 637                         "User component's _user_finalize() method raised an exception: ignoring:");
 638                 logw_exception(log_level);
 639         }
 640
 641         /*
 642          * Ignore any exception raised by the _user_finalize() method
 643          * because it won't change anything at this point: the component
 644          * is being destroyed anyway.
 645          */
 646         PyErr_Clear();
 647         Py_XDECREF(py_method_result);
 648         Py_DECREF(py_comp);
 649 }
 650
 651 static
 652 void component_class_source_finalize(bt_self_component_source *self_component_source)
 653 {
 654         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 655         component_class_finalize(self_component);
 656 }
 657
 658 static
 659 void component_class_filter_finalize(bt_self_component_filter *self_component_filter)
 660 {
 661         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 662         component_class_finalize(self_component);
 663 }
 664
 665 static
 666 void component_class_sink_finalize(bt_self_component_sink *self_component_sink)
 667 {
 668         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 669         component_class_finalize(self_component);
 670 }
 671
 672 static
 673 bt_bool component_class_can_seek_beginning(
 674                 bt_self_message_iterator *self_message_iterator)
 675 {
 676         PyObject *py_iter;
 677         PyObject *py_result = NULL;
 678         bt_bool can_seek_beginning = false;
 679
 680         py_iter = bt_self_message_iterator_get_data(self_message_iterator);
 681         BT_ASSERT(py_iter);
 682
 683         py_result = PyObject_GetAttrString(py_iter, "_bt_can_seek_beginning_from_native");
 684
 685         BT_ASSERT(!py_result || PyBool_Check(py_result));
 686
 687         if (py_result) {
 688                 can_seek_beginning = PyObject_IsTrue(py_result);
 689         } else {
 690                 /*
 691                  * Once can_seek_beginning can report errors, convert the
 692                  * exception to a status.  For now, log and return false;
 693                  */
 694                 loge_exception_message_iterator(self_message_iterator);
 695                 PyErr_Clear();
 696         }
 697
 698         Py_XDECREF(py_result);
 699
 700         return can_seek_beginning;
 701 }
 702
 703 static
 704 bt_component_class_message_iterator_seek_beginning_method_status
 705 component_class_seek_beginning(bt_self_message_iterator *self_message_iterator)
 706 {
 707         PyObject *py_iter;
 708         PyObject *py_result;
 709         bt_component_class_message_iterator_seek_beginning_method_status status;
 710
 711         py_iter = bt_self_message_iterator_get_data(self_message_iterator);
 712         BT_ASSERT(py_iter);
 713         py_result = PyObject_CallMethod(py_iter, "_bt_seek_beginning_from_native",
 714                 NULL);
 715         BT_ASSERT(!py_result || py_result == Py_None);
 716         status = py_exc_to_status_message_iterator(self_message_iterator);
 717         Py_XDECREF(py_result);
 718         return status;
 719 }
 720
 721 static
 722 bt_component_class_port_connected_method_status component_class_port_connected(
 723                 bt_self_component *self_component,
 724                 void *self_component_port,
 725                 swig_type_info *self_component_port_swig_type,
 726                 bt_port_type self_component_port_type,
 727                 const void *other_port,
 728                 swig_type_info *other_port_swig_type)
 729 {
 730         bt_component_class_port_connected_method_status status;
 731         PyObject *py_comp = NULL;
 732         PyObject *py_self_port_ptr = NULL;
 733         PyObject *py_other_port_ptr = NULL;
 734         PyObject *py_method_result = NULL;
 735         bt_logging_level log_level = get_self_component_log_level(
 736                 self_component);
 737
 738         py_comp = bt_self_component_get_data(self_component);
 739         BT_ASSERT(py_comp);
 740         py_self_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_port),
 741                 self_component_port_swig_type, 0);
 742         if (!py_self_port_ptr) {
 743                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 744                         "Failed to create a SWIG pointer object.");
 745                 status = __BT_FUNC_STATUS_MEMORY_ERROR;
 746                 goto end;
 747         }
 748
 749         py_other_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(other_port),
 750                 other_port_swig_type, 0);
 751         if (!py_other_port_ptr) {
 752                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
 753                         "Failed to create a SWIG pointer object.");
 754                 status = __BT_FUNC_STATUS_MEMORY_ERROR;
 755                 goto end;       }
 756
 757         py_method_result = PyObject_CallMethod(py_comp,
 758                 "_bt_port_connected_from_native", "(OiO)", py_self_port_ptr,
 759                 self_component_port_type, py_other_port_ptr);
 760         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 761         status = py_exc_to_status_component(self_component);
 762
 763 end:
 764         Py_XDECREF(py_self_port_ptr);
 765         Py_XDECREF(py_other_port_ptr);
 766         Py_XDECREF(py_method_result);
 767         return status;
 768 }
 769
 770 static
 771 bt_component_class_port_connected_method_status
 772 component_class_source_output_port_connected(
 773                 bt_self_component_source *self_component_source,
 774                 bt_self_component_port_output *self_component_port_output,
 775                 const bt_port_input *other_port_input)
 776 {
 777         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 778
 779         return component_class_port_connected(
 780                 self_component,
 781                 self_component_port_output,
 782                 SWIGTYPE_p_bt_self_component_port_output,
 783                 BT_PORT_TYPE_OUTPUT,
 784                 other_port_input,
 785                 SWIGTYPE_p_bt_port_input);
 786 }
 787
 788 static
 789 bt_component_class_port_connected_method_status
 790 component_class_filter_input_port_connected(
 791                 bt_self_component_filter *self_component_filter,
 792                 bt_self_component_port_input *self_component_port_input,
 793                 const bt_port_output *other_port_output)
 794 {
 795         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 796
 797         return component_class_port_connected(
 798                 self_component,
 799                 self_component_port_input,
 800                 SWIGTYPE_p_bt_self_component_port_input,
 801                 BT_PORT_TYPE_INPUT,
 802                 other_port_output,
 803                 SWIGTYPE_p_bt_port_output);
 804 }
 805
 806 static
 807 bt_component_class_port_connected_method_status
 808 component_class_filter_output_port_connected(
 809                 bt_self_component_filter *self_component_filter,
 810                 bt_self_component_port_output *self_component_port_output,
 811                 const bt_port_input *other_port_input)
 812 {
 813         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 814
 815         return component_class_port_connected(
 816                 self_component,
 817                 self_component_port_output,
 818                 SWIGTYPE_p_bt_self_component_port_output,
 819                 BT_PORT_TYPE_OUTPUT,
 820                 other_port_input,
 821                 SWIGTYPE_p_bt_port_input);
 822 }
 823
 824 static
 825 bt_component_class_port_connected_method_status
 826 component_class_sink_input_port_connected(
 827                 bt_self_component_sink *self_component_sink,
 828                 bt_self_component_port_input *self_component_port_input,
 829                 const bt_port_output *other_port_output)
 830 {
 831         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 832
 833         return component_class_port_connected(
 834                 self_component,
 835                 self_component_port_input,
 836                 SWIGTYPE_p_bt_self_component_port_input,
 837                 BT_PORT_TYPE_INPUT,
 838                 other_port_output,
 839                 SWIGTYPE_p_bt_port_output);
 840 }
 841
 842 static
 843 bt_component_class_sink_graph_is_configured_method_status
 844 component_class_sink_graph_is_configured(
 845                 bt_self_component_sink *self_component_sink)
 846 {
 847         PyObject *py_comp = NULL;
 848         PyObject *py_method_result = NULL;
 849         bt_component_class_sink_graph_is_configured_method_status status = __BT_FUNC_STATUS_OK;
 850         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 851
 852         py_comp = bt_self_component_get_data(self_component);
 853         py_method_result = PyObject_CallMethod(py_comp,
 854                 "_bt_graph_is_configured_from_native", NULL);
 855         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 856         status = py_exc_to_status_component(self_component);
 857         Py_XDECREF(py_method_result);
 858         return status;
 859 }
 860
 861 static
 862 bt_component_class_query_method_status component_class_query(
 863                 const bt_component_class *component_class,
 864                 bt_self_component_class *self_component_class,
 865                 const bt_query_executor *query_executor,
 866                 const char *object, const bt_value *params,
 867                 bt_logging_level log_level,
 868                 const bt_value **result)
 869 {
 870         PyObject *py_cls = NULL;
 871         PyObject *py_params_ptr = NULL;
 872         PyObject *py_query_exec_ptr = NULL;
 873         PyObject *py_query_func = NULL;
 874         PyObject *py_object = NULL;
 875         PyObject *py_results_addr = NULL;
 876         bt_component_class_query_method_status status = __BT_FUNC_STATUS_OK;
 877
 878         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 879         if (!py_cls) {
 880                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 881                         "Cannot find Python class associated to native component class: "
 882                         "comp-cls-addr=%p", component_class);
 883                 goto error;
 884         }
 885
 886         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 887                 SWIGTYPE_p_bt_value, 0);
 888         if (!py_params_ptr) {
 889                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 890                         "Failed to create a SWIG pointer object.");
 891                 goto error;
 892         }
 893
 894         py_query_exec_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(query_executor),
 895                 SWIGTYPE_p_bt_query_executor, 0);
 896         if (!py_query_exec_ptr) {
 897                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 898                         "Failed to create a SWIG pointer object.");
 899                 goto error;
 900         }
 901
 902         py_object = SWIG_FromCharPtr(object);
 903         if (!py_object) {
 904                 BT_LOG_WRITE_CUR_LVL(BT_LOG_ERROR, log_level, BT_LOG_TAG,
 905                         "Failed to create a Python string.");
 906                 goto error;
 907         }
 908
 909         py_results_addr = PyObject_CallMethod(py_cls,
 910                 "_bt_query_from_native", "(OOOi)", py_query_exec_ptr,
 911                 py_object, py_params_ptr, (int) log_level);
 912         if (!py_results_addr) {
 913                 BT_LOG_WRITE_CUR_LVL(BT_LOG_WARNING, log_level, BT_LOG_TAG,
 914                         "Failed to call Python class's _bt_query_from_native() method: "
 915                         "py-cls-addr=%p", py_cls);
 916                 status = py_exc_to_status_component_class(self_component_class,
 917                         log_level);
 918                 goto end;
 919         }
 920
 921         /*
 922          * The returned object, on success, is an integer object
 923          * (PyLong) containing the address of a BT value object (new
 924          * reference).
 925          */
 926         *result = PyLong_AsVoidPtr(py_results_addr);
 927         BT_ASSERT(!PyErr_Occurred());
 928         BT_ASSERT(*result);
 929         goto end;
 930
 931 error:
 932         PyErr_Clear();
 933         status = __BT_FUNC_STATUS_ERROR;
 934
 935 end:
 936         Py_XDECREF(py_params_ptr);
 937         Py_XDECREF(py_query_exec_ptr);
 938         Py_XDECREF(py_query_func);
 939         Py_XDECREF(py_object);
 940         Py_XDECREF(py_results_addr);
 941         return status;
 942 }
 943
 944 static
 945 bt_component_class_query_method_status component_class_source_query(
 946                 bt_self_component_class_source *self_component_class_source,
 947                 const bt_query_executor *query_executor,
 948                 const char *object, const bt_value *params,
 949                 bt_logging_level log_level,
 950                 const bt_value **result)
 951 {
 952         const bt_component_class_source *component_class_source = bt_self_component_class_source_as_component_class_source(self_component_class_source);
 953         const bt_component_class *component_class = bt_component_class_source_as_component_class_const(component_class_source);
 954         bt_self_component_class *self_component_class = bt_self_component_class_source_as_self_component_class(self_component_class_source);
 955
 956         return component_class_query(component_class, self_component_class, query_executor, object, params, log_level, result);
 957 }
 958
 959 static
 960 bt_component_class_query_method_status component_class_filter_query(
 961                 bt_self_component_class_filter *self_component_class_filter,
 962                 const bt_query_executor *query_executor,
 963                 const char *object, const bt_value *params,
 964                 bt_logging_level log_level,
 965                 const bt_value **result)
 966 {
 967         const bt_component_class_filter *component_class_filter = bt_self_component_class_filter_as_component_class_filter(self_component_class_filter);
 968         const bt_component_class *component_class = bt_component_class_filter_as_component_class_const(component_class_filter);
 969         bt_self_component_class *self_component_class = bt_self_component_class_filter_as_self_component_class(self_component_class_filter);
 970
 971         return component_class_query(component_class, self_component_class, query_executor, object, params, log_level, result);
 972 }
 973
 974 static
 975 bt_component_class_query_method_status component_class_sink_query(
 976                 bt_self_component_class_sink *self_component_class_sink,
 977                 const bt_query_executor *query_executor,
 978                 const char *object, const bt_value *params,
 979                 bt_logging_level log_level,
 980                 const bt_value **result)
 981 {
 982         const bt_component_class_sink *component_class_sink = bt_self_component_class_sink_as_component_class_sink(self_component_class_sink);
 983         const bt_component_class *component_class = bt_component_class_sink_as_component_class_const(component_class_sink);
 984         bt_self_component_class *self_component_class = bt_self_component_class_sink_as_self_component_class(self_component_class_sink);
 985
 986         return component_class_query(component_class, self_component_class, query_executor, object, params, log_level, result);
 987 }
 988
 989 static
 990 bt_component_class_message_iterator_init_method_status
 991 component_class_message_iterator_init(
 992                 bt_self_message_iterator *self_message_iterator,
 993                 bt_self_component *self_component,
 994                 bt_self_component_port_output *self_component_port_output)
 995 {
 996         bt_component_class_message_iterator_init_method_status status = __BT_FUNC_STATUS_OK;
 997         PyObject *py_comp_cls = NULL;
 998         PyObject *py_iter_cls = NULL;
 999         PyObject *py_iter_ptr = NULL;
1000         PyObject *py_component_port_output_ptr = NULL;
1001         PyObject *py_init_method_result = NULL;
1002         PyObject *py_iter = NULL;
1003         PyObject *py_comp;
1004         bt_logging_level log_level = get_self_component_log_level(
1005                 self_component);
1006
1007         py_comp = bt_self_component_get_data(self_component);
1008
1009         /* Find user's Python message iterator class */
1010         py_comp_cls = PyObject_GetAttrString(py_comp, "__class__");
1011         if (!py_comp_cls) {
1012                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
1013                         "Cannot get Python object's `__class__` attribute.");
1014                 goto python_error;
1015         }
1016
1017         py_iter_cls = PyObject_GetAttrString(py_comp_cls, "_iter_cls");
1018         if (!py_iter_cls) {
1019                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
1020                         "Cannot get Python class's `_iter_cls` attribute.");
1021                 goto python_error;
1022         }
1023
1024         py_iter_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_message_iterator),
1025                 SWIGTYPE_p_bt_self_message_iterator, 0);
1026         if (!py_iter_ptr) {
1027                 const char *err = "Failed to create a SWIG pointer object.";
1028
1029                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
1030                         "%s", err);
1031                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
1032                         self_message_iterator, err);
1033                 goto error;
1034         }
1035
1036         /*
1037          * Create object with borrowed native message iterator
1038          * reference:
1039          *
1040          *     py_iter = py_iter_cls.__new__(py_iter_cls, py_iter_ptr)
1041          */
1042         py_iter = PyObject_CallMethod(py_iter_cls, "__new__",
1043                 "(OO)", py_iter_cls, py_iter_ptr);
1044         if (!py_iter) {
1045                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
1046                         "Failed to call Python class's __new__() method: "
1047                         "py-cls-addr=%p", py_iter_cls);
1048                 goto python_error;
1049         }
1050
1051         /*
1052          * Initialize object:
1053          *
1054          *     py_iter.__init__(self_output_port)
1055          *
1056          * through the _init_for_native helper static method.
1057          *
1058          * At this point, py_iter._ptr is set, so this initialization
1059          * function has access to self._component (which gives it the
1060          * user Python component object from which the iterator was
1061          * created).
1062          */
1063         py_component_port_output_ptr = SWIG_NewPointerObj(
1064                 SWIG_as_voidptr(self_component_port_output),
1065                 SWIGTYPE_p_bt_self_component_port_output, 0);
1066         if (!py_component_port_output_ptr) {
1067                 const char *err = "Failed to create a SWIG pointer object.";
1068
1069                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
1070                         "%s", err);
1071                 BT_CURRENT_THREAD_ERROR_APPEND_CAUSE_FROM_MESSAGE_ITERATOR(
1072                         self_message_iterator, err);
1073                 goto error;
1074         }
1075
1076         py_init_method_result = PyObject_CallMethod(py_iter,
1077                 "_bt_init_from_native", "O", py_component_port_output_ptr);
1078         if (!py_init_method_result) {
1079                 BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_component,
1080                         "User's __init__() method failed:");
1081                 goto python_error;
1082         }
1083
1084         /*
1085          * Since the Python code can never instantiate a user-defined
1086          * message iterator class, the native message iterator
1087          * object does NOT belong to a user Python message iterator
1088          * object (borrowed reference). However this Python object is
1089          * owned by this native message iterator object.
1090          *
1091          * In the Python world, the lifetime of the native message
1092          * iterator is managed by a _GenericMessageIterator
1093          * instance:
1094          *
1095          *     _GenericMessageIterator instance:
1096          *         owns a native bt_message_iterator object (iter)
1097          *             owns a _UserMessageIterator instance (py_iter)
1098          *                 self._ptr is a borrowed reference to the
1099          *                 native bt_private_connection_private_message_iterator
1100          *                 object (iter)
1101          */
1102         bt_self_message_iterator_set_data(self_message_iterator, py_iter);
1103         py_iter = NULL;
1104         goto end;
1105
1106 python_error:
1107         /* Handling of errors that cause a Python exception to be set. */
1108         status = py_exc_to_status_message_iterator(self_message_iterator);
1109         BT_ASSERT(status != __BT_FUNC_STATUS_OK);
1110         goto end;
1111
1112 error:
1113         /* Handling of errors that don't cause a Python exception to be set. */
1114         status = __BT_FUNC_STATUS_ERROR;
1115
1116 end:
1117         BT_ASSERT(!PyErr_Occurred());
1118
1119         Py_XDECREF(py_comp_cls);
1120         Py_XDECREF(py_iter_cls);
1121         Py_XDECREF(py_iter_ptr);
1122         Py_XDECREF(py_component_port_output_ptr);
1123         Py_XDECREF(py_init_method_result);
1124         Py_XDECREF(py_iter);
1125         return status;
1126 }
1127
1128 static
1129 bt_component_class_message_iterator_init_method_status
1130 component_class_source_message_iterator_init(
1131                 bt_self_message_iterator *self_message_iterator,
1132                 bt_self_component_source *self_component_source,
1133                 bt_self_component_port_output *self_component_port_output)
1134 {
1135         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
1136
1137         return component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
1138 }
1139
1140 static
1141 bt_component_class_message_iterator_init_method_status
1142 component_class_filter_message_iterator_init(
1143                 bt_self_message_iterator *self_message_iterator,
1144                 bt_self_component_filter *self_component_filter,
1145                 bt_self_component_port_output *self_component_port_output)
1146 {
1147         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
1148
1149         return component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
1150 }
1151
1152 static
1153 void component_class_message_iterator_finalize(
1154                 bt_self_message_iterator *message_iterator)
1155 {
1156         PyObject *py_message_iter = bt_self_message_iterator_get_data(
1157                 message_iterator);
1158         PyObject *py_method_result = NULL;
1159
1160         BT_ASSERT(py_message_iter);
1161
1162         /* Call user's _user_finalize() method */
1163         py_method_result = PyObject_CallMethod(py_message_iter,
1164                 "_user_finalize", NULL);
1165
1166         if (PyErr_Occurred()) {
1167                 bt_self_component *self_comp =
1168                         bt_self_message_iterator_borrow_component(
1169                                 message_iterator);
1170                 bt_logging_level log_level = get_self_component_log_level(
1171                         self_comp);
1172
1173                 BT_COMP_LOG_CUR_LVL(BT_LOG_WARNING, log_level, self_comp,
1174                         "User's _user_finalize() method raised an exception: ignoring:");
1175                 logw_exception(get_self_message_iterator_log_level(
1176                         message_iterator));
1177         }
1178
1179         /*
1180          * Ignore any exception raised by the _user_finalize() method
1181          * because it won't change anything at this point: the component
1182          * is being destroyed anyway.
1183          */
1184         PyErr_Clear();
1185         Py_XDECREF(py_method_result);
1186         Py_DECREF(py_message_iter);
1187 }
1188
1189 /* Valid for both sources and filters. */
1190
1191 static
1192 bt_component_class_message_iterator_next_method_status
1193 component_class_message_iterator_next(
1194                 bt_self_message_iterator *message_iterator,
1195                 bt_message_array_const msgs, uint64_t capacity,
1196                 uint64_t *count)
1197 {
1198         bt_component_class_message_iterator_next_method_status status = __BT_FUNC_STATUS_OK;
1199         PyObject *py_message_iter = bt_self_message_iterator_get_data(message_iterator);
1200         PyObject *py_method_result = NULL;
1201
1202         BT_ASSERT(py_message_iter);
1203         py_method_result = PyObject_CallMethod(py_message_iter,
1204                 "_bt_next_from_native", NULL);
1205         if (!py_method_result) {
1206                 status = py_exc_to_status_message_iterator(message_iterator);
1207                 BT_ASSERT(status != __BT_FUNC_STATUS_OK);
1208                 goto end;
1209         }
1210
1211         /*
1212          * The returned object, on success, is an integer object
1213          * (PyLong) containing the address of a native message
1214          * object (which is now ours).
1215          */
1216         msgs[0] = PyLong_AsVoidPtr(py_method_result);
1217         *count = 1;
1218
1219         /* Clear potential overflow error; should never happen */
1220         BT_ASSERT(!PyErr_Occurred());
1221         goto end;
1222
1223 end:
1224         Py_XDECREF(py_method_result);
1225         return status;
1226 }
1227
1228 static
1229 bt_component_class_sink_consume_method_status
1230 component_class_sink_consume(bt_self_component_sink *self_component_sink)
1231 {
1232         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
1233         PyObject *py_comp = bt_self_component_get_data(self_component);
1234         PyObject *py_method_result = NULL;
1235         bt_component_class_sink_consume_method_status status;
1236
1237         BT_ASSERT(py_comp);
1238         py_method_result = PyObject_CallMethod(py_comp,
1239                 "_user_consume", NULL);
1240         status = py_exc_to_status_component(self_component);
1241         BT_ASSERT(py_method_result || status != __BT_FUNC_STATUS_OK);
1242         Py_XDECREF(py_method_result);
1243         return status;
1244 }
1245
1246 static
1247 int component_class_set_help_and_desc(
1248                 bt_component_class *component_class,
1249                 const char *description, const char *help)
1250 {
1251         int ret;
1252
1253         if (description) {
1254                 ret = bt_component_class_set_description(component_class, description);
1255                 if (ret) {
1256                         BT_LOGE("Cannot set component class's description: "
1257                                 "comp-cls-addr=%p", component_class);
1258                         goto end;
1259                 }
1260         }
1261
1262         if (help) {
1263                 ret = bt_component_class_set_help(component_class, help);
1264                 if (ret) {
1265                         BT_LOGE("Cannot set component class's help text: "
1266                                 "comp-cls-addr=%p", component_class);
1267                         goto end;
1268                 }
1269         }
1270
1271         ret = 0;
1272
1273 end:
1274         return ret;
1275 }
1276
1277 static
1278 bt_component_class_source *bt_bt2_component_class_source_create(
1279                 PyObject *py_cls, const char *name, const char *description,
1280                 const char *help)
1281 {
1282         bt_component_class_source *component_class_source;
1283         bt_component_class *component_class;
1284         int ret;
1285
1286         BT_ASSERT(py_cls);
1287         component_class_source = bt_component_class_source_create(name,
1288                 component_class_message_iterator_next);
1289         if (!component_class_source) {
1290                 BT_LOGE_STR("Cannot create source component class.");
1291                 goto end;
1292         }
1293
1294         component_class = bt_component_class_source_as_component_class(component_class_source);
1295
1296         if (component_class_set_help_and_desc(component_class, description, help)) {
1297                 goto end;
1298         }
1299
1300         ret = bt_component_class_source_set_init_method(component_class_source, component_class_source_init);
1301         BT_ASSERT(ret == 0);
1302         ret = bt_component_class_source_set_finalize_method(component_class_source, component_class_source_finalize);
1303         BT_ASSERT(ret == 0);
1304         ret = bt_component_class_source_set_message_iterator_can_seek_beginning_method(component_class_source,
1305                 component_class_can_seek_beginning);
1306         BT_ASSERT(ret == 0);
1307         ret = bt_component_class_source_set_message_iterator_seek_beginning_method(component_class_source,
1308                 component_class_seek_beginning);
1309         BT_ASSERT(ret == 0);
1310         ret = bt_component_class_source_set_output_port_connected_method(component_class_source,
1311                 component_class_source_output_port_connected);
1312         BT_ASSERT(ret == 0);
1313         ret = bt_component_class_source_set_query_method(component_class_source, component_class_source_query);
1314         BT_ASSERT(ret == 0);
1315         ret = bt_component_class_source_set_message_iterator_init_method(
1316                 component_class_source, component_class_source_message_iterator_init);
1317         BT_ASSERT(ret == 0);
1318         ret = bt_component_class_source_set_message_iterator_finalize_method(
1319                 component_class_source, component_class_message_iterator_finalize);
1320         BT_ASSERT(ret == 0);
1321         register_cc_ptr_to_py_cls(component_class, py_cls);
1322
1323 end:
1324         return component_class_source;
1325 }
1326
1327 static
1328 bt_component_class_filter *bt_bt2_component_class_filter_create(
1329                 PyObject *py_cls, const char *name, const char *description,
1330                 const char *help)
1331 {
1332         bt_component_class *component_class;
1333         bt_component_class_filter *component_class_filter;
1334         int ret;
1335
1336         BT_ASSERT(py_cls);
1337         component_class_filter = bt_component_class_filter_create(name,
1338                 component_class_message_iterator_next);
1339         if (!component_class_filter) {
1340                 BT_LOGE_STR("Cannot create filter component class.");
1341                 goto end;
1342         }
1343
1344         component_class = bt_component_class_filter_as_component_class(component_class_filter);
1345
1346         if (component_class_set_help_and_desc(component_class, description, help)) {
1347                 goto end;
1348         }
1349
1350         ret = bt_component_class_filter_set_init_method(component_class_filter, component_class_filter_init);
1351         BT_ASSERT(ret == 0);
1352         ret = bt_component_class_filter_set_finalize_method (component_class_filter, component_class_filter_finalize);
1353         BT_ASSERT(ret == 0);
1354         ret = bt_component_class_filter_set_message_iterator_can_seek_beginning_method(component_class_filter,
1355                 component_class_can_seek_beginning);
1356         BT_ASSERT(ret == 0);
1357         ret = bt_component_class_filter_set_message_iterator_seek_beginning_method(component_class_filter,
1358                 component_class_seek_beginning);
1359         BT_ASSERT(ret == 0);
1360         ret = bt_component_class_filter_set_input_port_connected_method(component_class_filter,
1361                 component_class_filter_input_port_connected);
1362         BT_ASSERT(ret == 0);
1363         ret = bt_component_class_filter_set_output_port_connected_method(component_class_filter,
1364                 component_class_filter_output_port_connected);
1365         BT_ASSERT(ret == 0);
1366         ret = bt_component_class_filter_set_query_method(component_class_filter, component_class_filter_query);
1367         BT_ASSERT(ret == 0);
1368         ret = bt_component_class_filter_set_message_iterator_init_method(
1369                 component_class_filter, component_class_filter_message_iterator_init);
1370         BT_ASSERT(ret == 0);
1371         ret = bt_component_class_filter_set_message_iterator_finalize_method(
1372                 component_class_filter, component_class_message_iterator_finalize);
1373         BT_ASSERT(ret == 0);
1374         register_cc_ptr_to_py_cls(component_class, py_cls);
1375
1376 end:
1377         return component_class_filter;
1378 }
1379
1380 static
1381 bt_component_class_sink *bt_bt2_component_class_sink_create(
1382                 PyObject *py_cls, const char *name, const char *description,
1383                 const char *help)
1384 {
1385         bt_component_class_sink *component_class_sink;
1386         bt_component_class *component_class;
1387         int ret;
1388
1389         BT_ASSERT(py_cls);
1390         component_class_sink = bt_component_class_sink_create(name, component_class_sink_consume);
1391
1392         if (!component_class_sink) {
1393                 BT_LOGE_STR("Cannot create sink component class.");
1394                 goto end;
1395         }
1396
1397         component_class = bt_component_class_sink_as_component_class(component_class_sink);
1398
1399         if (component_class_set_help_and_desc(component_class, description, help)) {
1400                 goto end;
1401         }
1402
1403         ret = bt_component_class_sink_set_init_method(component_class_sink, component_class_sink_init);
1404         BT_ASSERT(ret == 0);
1405         ret = bt_component_class_sink_set_finalize_method(component_class_sink, component_class_sink_finalize);
1406         BT_ASSERT(ret == 0);
1407         ret = bt_component_class_sink_set_input_port_connected_method(component_class_sink,
1408                 component_class_sink_input_port_connected);
1409         BT_ASSERT(ret == 0);
1410         ret = bt_component_class_sink_set_graph_is_configured_method(component_class_sink,
1411                 component_class_sink_graph_is_configured);
1412         BT_ASSERT(ret == 0);
1413         ret = bt_component_class_sink_set_query_method(component_class_sink, component_class_sink_query);
1414         BT_ASSERT(ret == 0);
1415         register_cc_ptr_to_py_cls(component_class, py_cls);
1416
1417 end:
1418         return component_class_sink;
1419 }
1420 %}
1421
1422 struct bt_component_class_source *bt_bt2_component_class_source_create(
1423                 PyObject *py_cls, const char *name, const char *description,
1424                 const char *help);
1425 struct bt_component_class_filter *bt_bt2_component_class_filter_create(
1426                 PyObject *py_cls, const char *name, const char *description,
1427                 const char *help);
1428 struct bt_component_class_sink *bt_bt2_component_class_sink_create(
1429                 PyObject *py_cls, const char *name, const char *description,
1430                 const char *help);
1431 void bt_bt2_cc_init_from_bt2(void);
1432 void bt_bt2_cc_exit_handler(void);