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-const.h>
  26 %include <babeltrace2/graph/component-class-source-const.h>
  27 %include <babeltrace2/graph/component-class-source.h>
  28 %include <babeltrace2/graph/component-class-filter-const.h>
  29 %include <babeltrace2/graph/component-class-filter.h>
  30 %include <babeltrace2/graph/component-class-sink-const.h>
  31 %include <babeltrace2/graph/component-class-sink.h>
  32 %include <babeltrace2/graph/self-component-class-source.h>
  33 %include <babeltrace2/graph/self-component-class-filter.h>
  34 %include <babeltrace2/graph/self-component-class-sink.h>
  35
  36 %{
  37 /*
  38  * This hash table associates a BT component class object address to a
  39  * user-defined Python class (PyObject *). The keys and values are NOT
  40  * owned by this hash table. The Python class objects are owned by the
  41  * Python module, which should not be unloaded until it is not possible
  42  * to create a user Python component anyway.
  43  *
  44  * This hash table is written to when a user-defined Python component
  45  * class is created by one of the bt_py3_component_class_*_create()
  46  * functions.
  47  *
  48  * This function is read from when a user calls bt_component_create()
  49  * with a component class pointer created by one of the functions above.
  50  * In this case, the original Python class needs to be found to
  51  * instantiate it and associate the created Python component object with
  52  * a BT component object instance.
  53  */
  54
  55 static GHashTable *bt_cc_ptr_to_py_cls;
  56
  57 static void register_cc_ptr_to_py_cls(struct bt_component_class *bt_cc,
  58                 PyObject *py_cls)
  59 {
  60         if (!bt_cc_ptr_to_py_cls) {
  61                 /*
  62                  * Lazy-initializing this GHashTable because GLib
  63                  * might not be initialized yet and it needs to be
  64                  * before we call g_hash_table_new()
  65                  */
  66                 BT_LOGD_STR("Creating native component class to Python component class hash table.");
  67                 bt_cc_ptr_to_py_cls = g_hash_table_new(g_direct_hash, g_direct_equal);
  68                 BT_ASSERT(bt_cc_ptr_to_py_cls);
  69         }
  70
  71         g_hash_table_insert(bt_cc_ptr_to_py_cls, (gpointer) bt_cc,
  72                 (gpointer) py_cls);
  73 }
  74
  75 static PyObject *lookup_cc_ptr_to_py_cls(const bt_component_class *bt_cc)
  76 {
  77         if (!bt_cc_ptr_to_py_cls) {
  78                 BT_LOGW("Cannot look up Python component class because hash table is NULL: "
  79                         "comp-cls-addr=%p", bt_cc);
  80                 return NULL;
  81         }
  82
  83         return (PyObject *) g_hash_table_lookup(bt_cc_ptr_to_py_cls,
  84                 (gconstpointer) bt_cc);
  85 }
  86
  87
  88 /*
  89  * Useful Python objects.
  90  */
  91
  92 static PyObject *py_mod_bt2 = NULL;
  93 static PyObject *py_mod_bt2_exc_error_type = NULL;
  94 static PyObject *py_mod_bt2_exc_try_again_type = NULL;
  95 static PyObject *py_mod_bt2_exc_stop_type = NULL;
  96 static PyObject *py_mod_bt2_exc_msg_iter_canceled_type = NULL;
  97 static PyObject *py_mod_bt2_exc_invalid_query_object_type = NULL;
  98 static PyObject *py_mod_bt2_exc_invalid_query_params_type = NULL;
  99
 100 static void bt_py3_cc_init_from_bt2(void)
 101 {
 102         /*
 103          * This is called once the bt2 package is loaded.
 104          *
 105          * Those modules and functions are needed while the package is
 106          * used. Loading them here is safe because we know the bt2
 107          * package is imported, and we know that the user cannot use the
 108          * code here without importing bt2 first.
 109          */
 110         py_mod_bt2 = PyImport_ImportModule("bt2");
 111         BT_ASSERT(py_mod_bt2);
 112         py_mod_bt2_exc_error_type =
 113                 PyObject_GetAttrString(py_mod_bt2, "Error");
 114         BT_ASSERT(py_mod_bt2_exc_error_type);
 115         py_mod_bt2_exc_try_again_type =
 116                 PyObject_GetAttrString(py_mod_bt2, "TryAgain");
 117         BT_ASSERT(py_mod_bt2_exc_try_again_type);
 118         py_mod_bt2_exc_stop_type =
 119                 PyObject_GetAttrString(py_mod_bt2, "Stop");
 120         BT_ASSERT(py_mod_bt2_exc_stop_type);
 121         py_mod_bt2_exc_invalid_query_object_type =
 122                 PyObject_GetAttrString(py_mod_bt2, "InvalidQueryObject");
 123         BT_ASSERT(py_mod_bt2_exc_invalid_query_object_type);
 124         py_mod_bt2_exc_invalid_query_params_type =
 125                 PyObject_GetAttrString(py_mod_bt2, "InvalidQueryParams");
 126         BT_ASSERT(py_mod_bt2_exc_invalid_query_params_type);
 127 }
 128
 129 static void bt_py3_cc_exit_handler(void)
 130 {
 131         /*
 132          * This is an exit handler (set by the bt2 package).
 133          *
 134          * We only give back the references that we took in
 135          * bt_py3_cc_init_from_bt2() here. The global variables continue
 136          * to exist for the code of this file, but they are now borrowed
 137          * references. If this code is executed, it means that somehow
 138          * the modules are still loaded, so it should be safe to use
 139          * them even without a strong reference.
 140          *
 141          * We cannot do this in the library's destructor because it
 142          * gets executed once Python is already finalized.
 143          */
 144         Py_XDECREF(py_mod_bt2);
 145         Py_XDECREF(py_mod_bt2_exc_error_type);
 146         Py_XDECREF(py_mod_bt2_exc_try_again_type);
 147         Py_XDECREF(py_mod_bt2_exc_stop_type);
 148         Py_XDECREF(py_mod_bt2_exc_msg_iter_canceled_type);
 149         Py_XDECREF(py_mod_bt2_exc_invalid_query_object_type);
 150         Py_XDECREF(py_mod_bt2_exc_invalid_query_params_type);
 151 }
 152
 153
 154 /* Library destructor */
 155
 156 __attribute__((destructor))
 157 static void bt_py3_native_comp_class_dtor(void) {
 158         /* Destroy component class association hash table */
 159         if (bt_cc_ptr_to_py_cls) {
 160                 BT_LOGD_STR("Destroying native component class to Python component class hash table.");
 161                 g_hash_table_destroy(bt_cc_ptr_to_py_cls);
 162         }
 163 }
 164
 165
 166 // TODO: maybe we can wrap code in the Python methods (e.g. _query_from_native)
 167 // in a try catch and print the error there instead, it would be simpler.
 168 static
 169 void bt2_py_loge_exception(void)
 170 {
 171         PyObject *type = NULL;
 172         PyObject *value = NULL;
 173         PyObject *traceback = NULL;
 174         PyObject *traceback_module = NULL;
 175         PyObject *format_exception_func = NULL;
 176         PyObject *exc_str_list = NULL;
 177         GString *msg_buf = NULL;
 178         Py_ssize_t i;
 179
 180         BT_ASSERT(PyErr_Occurred() != NULL);
 181
 182         PyErr_Fetch(&type, &value, &traceback);
 183
 184         BT_ASSERT(type != NULL);
 185
 186         /*
 187         * traceback can be NULL, when we fail to call a Python function from the
 188         * native code (there is no Python stack at that point).  E.g.:
 189         *
 190         *   TypeError: _query_from_native() takes 5 positional arguments but 8 were given
 191         */
 192
 193
 194         /* Make sure `value` is what we expected - an instance of `type`. */
 195         PyErr_NormalizeException(&type, &value, &traceback);
 196
 197         traceback_module = PyImport_ImportModule("traceback");
 198         if (!traceback_module) {
 199                 BT_LOGE_STR("Failed to log Python exception (could not import traceback module).");
 200                 goto end;
 201         }
 202
 203         format_exception_func = PyObject_GetAttrString(traceback_module,
 204                 traceback ? "format_exception" : "format_exception_only");
 205         if (!format_exception_func) {
 206                 BT_LOGE_STR("Failed to log Python exception (could not find format_exception).");
 207                 goto end;
 208         }
 209
 210         if (!PyCallable_Check(format_exception_func)) {
 211                 BT_LOGE_STR("Failed to log Python exception (format_exception is not callable).");
 212                 goto end;
 213         }
 214
 215         exc_str_list = PyObject_CallFunctionObjArgs(format_exception_func, type, value, traceback, NULL);
 216         if (!exc_str_list) {
 217                 PyErr_Print();
 218                 BT_LOGE_STR("Failed to log Python exception (call to format_exception failed).");
 219                 goto end;
 220         }
 221
 222         msg_buf = g_string_new(NULL);
 223
 224         for (i = 0; i < PyList_Size(exc_str_list); i++) {
 225                 PyObject *exc_str = PyList_GetItem(exc_str_list, i);
 226                 const char *str = PyUnicode_AsUTF8(exc_str);
 227                 if (!str) {
 228                         BT_LOGE_STR("Failed to log Python exception (failed to convert exception to string).");
 229                         goto end;
 230                 }
 231
 232                 g_string_append(msg_buf, str);
 233         }
 234
 235         BT_LOGE_STR(msg_buf->str);
 236
 237 end:
 238         if (msg_buf) {
 239                 g_string_free(msg_buf, TRUE);
 240         }
 241         Py_XDECREF(exc_str_list);
 242         Py_XDECREF(format_exception_func);
 243         Py_XDECREF(traceback_module);
 244
 245         /* PyErr_Restore takes our references. */
 246         PyErr_Restore(type, value, traceback);
 247 }
 248
 249 static bt_self_component_status bt_py3_exc_to_self_component_status(void)
 250 {
 251         bt_self_component_status status = BT_SELF_COMPONENT_STATUS_OK;
 252         PyObject *exc = PyErr_Occurred();
 253
 254         if (!exc) {
 255                 goto end;
 256         }
 257
 258         if (PyErr_GivenExceptionMatches(exc,
 259                         py_mod_bt2_exc_try_again_type)) {
 260                 status = BT_SELF_COMPONENT_STATUS_AGAIN;
 261         } else if (PyErr_GivenExceptionMatches(exc,
 262                         py_mod_bt2_exc_stop_type)) {
 263                 status = BT_SELF_COMPONENT_STATUS_END;
 264         } else {
 265                 bt2_py_loge_exception();
 266                 status = BT_SELF_COMPONENT_STATUS_ERROR;
 267         }
 268
 269 end:
 270         PyErr_Clear();
 271         return status;
 272 }
 273
 274 /* Component class proxy methods (delegate to the attached Python object) */
 275
 276 static bt_self_message_iterator_status
 277 bt_py3_exc_to_self_message_iterator_status(void)
 278 {
 279         enum bt_self_message_iterator_status status =
 280                 BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
 281         PyObject *exc = PyErr_Occurred();
 282
 283         if (!exc) {
 284                 goto end;
 285         }
 286
 287         if (PyErr_GivenExceptionMatches(exc, py_mod_bt2_exc_stop_type)) {
 288                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_END;
 289         } else if (PyErr_GivenExceptionMatches(exc, py_mod_bt2_exc_try_again_type)) {
 290                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_AGAIN;
 291         } else {
 292                 bt2_py_loge_exception();
 293                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
 294         }
 295
 296 end:
 297         PyErr_Clear();
 298         return status;
 299 }
 300
 301 static enum bt_query_status bt_py3_exc_to_query_status(void)
 302 {
 303         enum bt_query_status status = BT_QUERY_STATUS_OK;
 304         PyObject *exc = PyErr_Occurred();
 305
 306         if (!exc) {
 307                 goto end;
 308         }
 309
 310         if (PyErr_GivenExceptionMatches(exc,
 311                         py_mod_bt2_exc_invalid_query_object_type)) {
 312                 status = BT_QUERY_STATUS_INVALID_OBJECT;
 313         } else if (PyErr_GivenExceptionMatches(exc,
 314                         py_mod_bt2_exc_invalid_query_params_type)) {
 315                 status = BT_QUERY_STATUS_INVALID_PARAMS;
 316         } else if (PyErr_GivenExceptionMatches(exc,
 317                         py_mod_bt2_exc_try_again_type)) {
 318                 status = BT_QUERY_STATUS_AGAIN;
 319         } else {
 320                 bt2_py_loge_exception();
 321                 status = BT_QUERY_STATUS_ERROR;
 322         }
 323
 324 end:
 325         PyErr_Clear();
 326         return status;
 327 }
 328
 329 static bt_self_component_status
 330 bt_py3_component_class_init(
 331                 bt_self_component *self_component,
 332                 void *self_component_v,
 333                 swig_type_info *self_comp_cls_type_swig_type,
 334                 const bt_value *params,
 335                 void *init_method_data)
 336 {
 337         const bt_component *component = bt_self_component_as_component(self_component);
 338         const bt_component_class *component_class = bt_component_borrow_class_const(component);
 339         bt_self_component_status status = BT_SELF_COMPONENT_STATUS_OK;
 340         PyObject *py_cls = NULL;
 341         PyObject *py_comp = NULL;
 342         PyObject *py_params_ptr = NULL;
 343         PyObject *py_comp_ptr = NULL;
 344
 345         (void) init_method_data;
 346
 347         BT_ASSERT(self_component);
 348         BT_ASSERT(self_component_v);
 349         BT_ASSERT(self_comp_cls_type_swig_type);
 350
 351         /*
 352          * Get the user-defined Python class which created this
 353          * component's class in the first place (borrowed
 354          * reference).
 355          */
 356         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 357         if (!py_cls) {
 358                 BT_LOGE("Cannot find Python class associated to native component class: "
 359                         "comp-cls-addr=%p", component_class);
 360                 goto error;
 361         }
 362
 363         /* Parameters pointer -> SWIG pointer Python object */
 364         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 365                 SWIGTYPE_p_bt_value, 0);
 366         if (!py_params_ptr) {
 367                 BT_LOGE_STR("Failed to create a SWIG pointer object.");
 368                 goto error;
 369         }
 370
 371         py_comp_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_v),
 372                 self_comp_cls_type_swig_type, 0);
 373         if (!py_comp_ptr) {
 374                 BT_LOGE_STR("Failed to create a SWIG pointer object.");
 375                 goto error;
 376         }
 377
 378         /*
 379          * Do the equivalent of this:
 380          *
 381          *     py_comp = py_cls._init_from_native(py_comp_ptr, py_params_ptr)
 382          *
 383          * _UserComponentType._init_from_native() calls the Python
 384          * component object's __init__() function.
 385          */
 386         py_comp = PyObject_CallMethod(py_cls,
 387                 "_init_from_native", "(OO)", py_comp_ptr, py_params_ptr);
 388         if (!py_comp) {
 389                 bt2_py_loge_exception();
 390                 BT_LOGE("Failed to call Python class's _init_from_native() method: "
 391                         "py-cls-addr=%p", py_cls);
 392
 393                 goto error;
 394         }
 395
 396         /*
 397          * Our user Python component object is now fully created and
 398          * initialized by the user. Since we just created it, this
 399          * native component is its only (persistent) owner.
 400          */
 401         bt_self_component_set_data(self_component, py_comp);
 402         py_comp = NULL;
 403         goto end;
 404
 405 error:
 406         status = BT_SELF_COMPONENT_STATUS_ERROR;
 407
 408         /*
 409          * Clear any exception: we're returning a bad status anyway. If
 410          * this call originated from Python (creation from a plugin's
 411          * component class, for example), then the user gets an
 412          * appropriate creation error.
 413          */
 414         PyErr_Clear();
 415
 416 end:
 417         Py_XDECREF(py_comp);
 418         Py_XDECREF(py_params_ptr);
 419         Py_XDECREF(py_comp_ptr);
 420         return status;
 421 }
 422
 423 /*
 424  * Method of bt_component_class_source to initialize a bt_self_component_source
 425  * of that class.
 426  */
 427
 428 static bt_self_component_status
 429 bt_py3_component_class_source_init(bt_self_component_source *self_component_source,
 430                 const bt_value *params, void *init_method_data)
 431 {
 432         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 433         return bt_py3_component_class_init(
 434                 self_component,
 435                 self_component_source,
 436                 SWIGTYPE_p_bt_self_component_source,
 437                 params, init_method_data);
 438 }
 439
 440 static bt_self_component_status
 441 bt_py3_component_class_filter_init(bt_self_component_filter *self_component_filter,
 442                 const bt_value *params, void *init_method_data)
 443 {
 444         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 445         return bt_py3_component_class_init(
 446                 self_component,
 447                 self_component_filter,
 448                 SWIGTYPE_p_bt_self_component_filter,
 449                 params, init_method_data);
 450 }
 451
 452 static bt_self_component_status
 453 bt_py3_component_class_sink_init(bt_self_component_sink *self_component_sink,
 454                 const bt_value *params, void *init_method_data)
 455 {
 456         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 457         return bt_py3_component_class_init(
 458                 self_component,
 459                 self_component_sink,
 460                 SWIGTYPE_p_bt_self_component_sink,
 461                 params, init_method_data);
 462 }
 463
 464 static void bt_py3_component_class_finalize(bt_self_component *self_component)
 465 {
 466         PyObject *py_comp = bt_self_component_get_data(self_component);
 467         BT_ASSERT(py_comp);
 468
 469         /* Call user's _finalize() method */
 470         PyObject *py_method_result = PyObject_CallMethod(py_comp,
 471                 "_finalize", NULL);
 472
 473         if (PyErr_Occurred()) {
 474                 BT_LOGW("User's _finalize() method raised an exception: ignoring.");
 475         }
 476
 477         /*
 478          * Ignore any exception raised by the _finalize() method because
 479          * it won't change anything at this point: the component is
 480          * being destroyed anyway.
 481          */
 482         PyErr_Clear();
 483         Py_XDECREF(py_method_result);
 484         Py_DECREF(py_comp);
 485 }
 486
 487 static void
 488 bt_py3_component_class_source_finalize(bt_self_component_source *self_component_source)
 489 {
 490         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 491         bt_py3_component_class_finalize(self_component);
 492 }
 493
 494 static void
 495 bt_py3_component_class_filter_finalize(bt_self_component_filter *self_component_filter)
 496 {
 497         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 498         bt_py3_component_class_finalize(self_component);
 499 }
 500
 501 static void
 502 bt_py3_component_class_sink_finalize(bt_self_component_sink *self_component_sink)
 503 {
 504         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 505         bt_py3_component_class_finalize(self_component);
 506 }
 507
 508 static bt_self_component_status
 509 bt_py3_component_class_port_connected(
 510                 bt_self_component *self_component,
 511                 void *self_component_port,
 512                 swig_type_info *self_component_port_swig_type,
 513                 bt_port_type self_component_port_type,
 514                 const void *other_port,
 515                 swig_type_info *other_port_swig_type)
 516 {
 517         bt_self_component_status status;
 518         PyObject *py_comp = NULL;
 519         PyObject *py_self_port_ptr = NULL;
 520         PyObject *py_other_port_ptr = NULL;
 521         PyObject *py_method_result = NULL;
 522
 523         py_comp = bt_self_component_get_data(self_component);
 524         BT_ASSERT(py_comp);
 525
 526         py_self_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_port),
 527                 self_component_port_swig_type, 0);
 528         if (!py_self_port_ptr) {
 529                 BT_LOGF_STR("Failed to create a SWIG pointer object.");
 530                 status = BT_SELF_COMPONENT_STATUS_NOMEM;
 531                 goto end;
 532         }
 533
 534         py_other_port_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(other_port),
 535                 other_port_swig_type, 0);
 536         if (!py_other_port_ptr) {
 537                 BT_LOGF_STR("Failed to create a SWIG pointer object.");
 538                 status = BT_SELF_COMPONENT_STATUS_NOMEM;
 539                 goto end;       }
 540
 541         py_method_result = PyObject_CallMethod(py_comp,
 542                 "_port_connected_from_native", "(OiO)", py_self_port_ptr,
 543                 self_component_port_type, py_other_port_ptr);
 544
 545         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 546
 547         status = bt_py3_exc_to_self_component_status();
 548
 549 end:
 550         Py_XDECREF(py_self_port_ptr);
 551         Py_XDECREF(py_other_port_ptr);
 552         Py_XDECREF(py_method_result);
 553
 554         return status;
 555 }
 556
 557 static bt_self_component_status
 558 bt_py3_component_class_source_output_port_connected(
 559                 bt_self_component_source *self_component_source,
 560                 bt_self_component_port_output *self_component_port_output,
 561                 const bt_port_input *other_port_input)
 562 {
 563         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 564
 565         return bt_py3_component_class_port_connected(
 566                 self_component,
 567                 self_component_port_output,
 568                 SWIGTYPE_p_bt_self_component_port_output,
 569                 BT_PORT_TYPE_OUTPUT,
 570                 other_port_input,
 571                 SWIGTYPE_p_bt_port_input);
 572 }
 573
 574 static bt_self_component_status
 575 bt_py3_component_class_filter_input_port_connected(
 576                 bt_self_component_filter *self_component_filter,
 577                 bt_self_component_port_input *self_component_port_input,
 578                 const bt_port_output *other_port_output)
 579 {
 580         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 581
 582         return bt_py3_component_class_port_connected(
 583                 self_component,
 584                 self_component_port_input,
 585                 SWIGTYPE_p_bt_self_component_port_input,
 586                 BT_PORT_TYPE_INPUT,
 587                 other_port_output,
 588                 SWIGTYPE_p_bt_port_output);
 589 }
 590
 591 static bt_self_component_status
 592 bt_py3_component_class_filter_output_port_connected(
 593                 bt_self_component_filter *self_component_filter,
 594                 bt_self_component_port_output *self_component_port_output,
 595                 const bt_port_input *other_port_input)
 596 {
 597         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 598
 599         return bt_py3_component_class_port_connected(
 600                 self_component,
 601                 self_component_port_output,
 602                 SWIGTYPE_p_bt_self_component_port_output,
 603                 BT_PORT_TYPE_OUTPUT,
 604                 other_port_input,
 605                 SWIGTYPE_p_bt_port_input);
 606 }
 607
 608 static bt_self_component_status
 609 bt_py3_component_class_sink_input_port_connected(
 610                 bt_self_component_sink *self_component_sink,
 611                 bt_self_component_port_input *self_component_port_input,
 612                 const bt_port_output *other_port_output)
 613 {
 614         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 615
 616         return bt_py3_component_class_port_connected(
 617                 self_component,
 618                 self_component_port_input,
 619                 SWIGTYPE_p_bt_self_component_port_input,
 620                 BT_PORT_TYPE_INPUT,
 621                 other_port_output,
 622                 SWIGTYPE_p_bt_port_output);
 623 }
 624
 625 static bt_self_component_status
 626 bt_py3_component_class_sink_graph_is_configured(bt_self_component_sink *self_component_sink)
 627 {
 628         PyObject *py_comp = NULL;
 629         PyObject *py_method_result = NULL;
 630         bt_self_component_status status = BT_SELF_COMPONENT_STATUS_OK;
 631         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 632
 633         py_comp = bt_self_component_get_data(self_component);
 634         py_method_result = PyObject_CallMethod(py_comp,
 635                 "_graph_is_configured_from_native", NULL);
 636
 637         BT_ASSERT(!py_method_result || py_method_result == Py_None);
 638
 639         status = bt_py3_exc_to_self_component_status();
 640
 641         Py_XDECREF(py_method_result);
 642
 643         return status;
 644 }
 645
 646 static bt_query_status
 647 bt_py3_component_class_query(
 648                 const bt_component_class *component_class,
 649                 const bt_query_executor *query_executor,
 650                 const char *object, const bt_value *params,
 651                 bt_logging_level log_level,
 652                 const bt_value **result)
 653 {
 654         PyObject *py_cls = NULL;
 655         PyObject *py_params_ptr = NULL;
 656         PyObject *py_query_exec_ptr = NULL;
 657         PyObject *py_query_func = NULL;
 658         PyObject *py_object = NULL;
 659         PyObject *py_results_addr = NULL;
 660         bt_query_status status = BT_QUERY_STATUS_OK;
 661
 662         py_cls = lookup_cc_ptr_to_py_cls(component_class);
 663         if (!py_cls) {
 664                 BT_LOGE("Cannot find Python class associated to native component class: "
 665                         "comp-cls-addr=%p", component_class);
 666                 goto error;
 667         }
 668
 669         py_params_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(params),
 670                 SWIGTYPE_p_bt_value, 0);
 671         if (!py_params_ptr) {
 672                 BT_LOGE_STR("Failed to create a SWIG pointer object.");
 673                 goto error;
 674         }
 675
 676         py_query_exec_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(query_executor),
 677                 SWIGTYPE_p_bt_query_executor, 0);
 678         if (!py_query_exec_ptr) {
 679                 BT_LOGE_STR("Failed to create a SWIG pointer object.");
 680                 goto error;
 681         }
 682
 683         py_object = SWIG_FromCharPtr(object);
 684         if (!py_object) {
 685                 BT_LOGE_STR("Failed to create a Python string.");
 686                 goto error;
 687         }
 688
 689         py_results_addr = PyObject_CallMethod(py_cls,
 690                 "_query_from_native", "(OOOi)", py_query_exec_ptr,
 691                 py_object, py_params_ptr, (int) log_level);
 692
 693         if (!py_results_addr) {
 694                 BT_LOGE("Failed to call Python class's _query_from_native() method: "
 695                         "py-cls-addr=%p", py_cls);
 696                 status = bt_py3_exc_to_query_status();
 697                 goto end;
 698         }
 699
 700         /*
 701          * The returned object, on success, is an integer object
 702          * (PyLong) containing the address of a BT value object (new
 703          * reference).
 704          */
 705         *result = PyLong_AsVoidPtr(py_results_addr);
 706         BT_ASSERT(!PyErr_Occurred());
 707         BT_ASSERT(*result);
 708         goto end;
 709
 710 error:
 711         PyErr_Clear();
 712         status = BT_QUERY_STATUS_ERROR;
 713
 714 end:
 715         Py_XDECREF(py_params_ptr);
 716         Py_XDECREF(py_query_exec_ptr);
 717         Py_XDECREF(py_query_func);
 718         Py_XDECREF(py_object);
 719         Py_XDECREF(py_results_addr);
 720         return status;
 721 }
 722
 723 static bt_query_status
 724 bt_py3_component_class_source_query(
 725                 bt_self_component_class_source *self_component_class_source,
 726                 const bt_query_executor *query_executor,
 727                 const char *object, const bt_value *params,
 728                 bt_logging_level log_level,
 729                 const bt_value **result)
 730 {
 731         const bt_component_class_source *component_class_source = bt_self_component_class_source_as_component_class_source(self_component_class_source);
 732         const bt_component_class *component_class = bt_component_class_source_as_component_class_const(component_class_source);
 733         return bt_py3_component_class_query(component_class, query_executor, object, params, log_level, result);
 734 }
 735
 736 static bt_query_status
 737 bt_py3_component_class_filter_query(
 738                 bt_self_component_class_filter *self_component_class_filter,
 739                 const bt_query_executor *query_executor,
 740                 const char *object, const bt_value *params,
 741                 bt_logging_level log_level,
 742                 const bt_value **result)
 743 {
 744         const bt_component_class_filter *component_class_filter = bt_self_component_class_filter_as_component_class_filter(self_component_class_filter);
 745         const bt_component_class *component_class = bt_component_class_filter_as_component_class_const(component_class_filter);
 746         return bt_py3_component_class_query(component_class, query_executor, object, params, log_level, result);
 747 }
 748
 749 static bt_query_status
 750 bt_py3_component_class_sink_query(
 751                 bt_self_component_class_sink *self_component_class_sink,
 752                 const bt_query_executor *query_executor,
 753                 const char *object, const bt_value *params,
 754                 bt_logging_level log_level,
 755                 const bt_value **result)
 756 {
 757         const bt_component_class_sink *component_class_sink = bt_self_component_class_sink_as_component_class_sink(self_component_class_sink);
 758         const bt_component_class *component_class = bt_component_class_sink_as_component_class_const(component_class_sink);
 759         return bt_py3_component_class_query(component_class, query_executor, object, params, log_level, result);
 760 }
 761
 762 static bt_self_message_iterator_status
 763 bt_py3_component_class_message_iterator_init(
 764                 bt_self_message_iterator *self_message_iterator,
 765                 bt_self_component *self_component,
 766                 bt_self_component_port_output *self_component_port_output)
 767 {
 768         bt_self_message_iterator_status status = BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
 769         PyObject *py_comp_cls = NULL;
 770         PyObject *py_iter_cls = NULL;
 771         PyObject *py_iter_ptr = NULL;
 772         PyObject *py_component_port_output_ptr = NULL;
 773         PyObject *py_init_method_result = NULL;
 774         PyObject *py_iter = NULL;
 775         PyObject *py_comp;
 776
 777         py_comp = bt_self_component_get_data(self_component);
 778
 779         /* Find user's Python message iterator class */
 780         py_comp_cls = PyObject_GetAttrString(py_comp, "__class__");
 781         if (!py_comp_cls) {
 782                 BT_LOGE_STR("Cannot get Python object's `__class__` attribute.");
 783                 goto error;
 784         }
 785
 786         py_iter_cls = PyObject_GetAttrString(py_comp_cls, "_iter_cls");
 787         if (!py_iter_cls) {
 788                 BT_LOGE_STR("Cannot get Python class's `_iter_cls` attribute.");
 789                 goto error;
 790         }
 791
 792         py_iter_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_message_iterator),
 793                 SWIGTYPE_p_bt_self_message_iterator, 0);
 794         if (!py_iter_ptr) {
 795                 BT_LOGE_STR("Failed to create a SWIG pointer object.");
 796                 goto error;
 797         }
 798
 799         /*
 800          * Create object with borrowed native message iterator
 801          * reference:
 802          *
 803          *     py_iter = py_iter_cls.__new__(py_iter_cls, py_iter_ptr)
 804          */
 805         py_iter = PyObject_CallMethod(py_iter_cls, "__new__",
 806                 "(OO)", py_iter_cls, py_iter_ptr);
 807         if (!py_iter) {
 808                 BT_LOGE("Failed to call Python class's __new__() method: "
 809                         "py-cls-addr=%p", py_iter_cls);
 810                 bt2_py_loge_exception();
 811                 goto error;
 812         }
 813
 814         /*
 815          * Initialize object:
 816          *
 817          *     py_iter.__init__(self_output_port)
 818          *
 819          * through the _init_for_native helper static method.
 820          *
 821          * At this point, py_iter._ptr is set, so this initialization
 822          * function has access to self._component (which gives it the
 823          * user Python component object from which the iterator was
 824          * created).
 825          */
 826         py_component_port_output_ptr = SWIG_NewPointerObj(SWIG_as_voidptr(self_component_port_output),
 827                 SWIGTYPE_p_bt_self_component_port_output, 0);
 828         if (!py_component_port_output_ptr) {
 829                 BT_LOGE_STR("Failed to create a SWIG pointer object.");
 830                 goto error;
 831         }
 832
 833         py_init_method_result = PyObject_CallMethod(py_iter, "_init_from_native", "O", py_component_port_output_ptr);
 834         if (!py_init_method_result) {
 835                 BT_LOGE_STR("User's __init__() method failed.");
 836                 bt2_py_loge_exception();
 837                 goto error;
 838         }
 839
 840         /*
 841          * Since the Python code can never instantiate a user-defined
 842          * message iterator class, the native message iterator
 843          * object does NOT belong to a user Python message iterator
 844          * object (borrowed reference). However this Python object is
 845          * owned by this native message iterator object.
 846          *
 847          * In the Python world, the lifetime of the native message
 848          * iterator is managed by a _GenericMessageIterator
 849          * instance:
 850          *
 851          *     _GenericMessageIterator instance:
 852          *         owns a native bt_message_iterator object (iter)
 853          *             owns a _UserMessageIterator instance (py_iter)
 854          *                 self._ptr is a borrowed reference to the
 855          *                 native bt_private_connection_private_message_iterator
 856          *                 object (iter)
 857          */
 858         bt_self_message_iterator_set_data(self_message_iterator, py_iter);
 859         py_iter = NULL;
 860         goto end;
 861
 862 error:
 863         status = bt_py3_exc_to_self_message_iterator_status();
 864         if (status == BT_SELF_MESSAGE_ITERATOR_STATUS_OK) {
 865                 /*
 866                  * Looks like there wasn't any exception from the Python
 867                  * side, but we're still in an error state here.
 868                  */
 869                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
 870         }
 871
 872         /*
 873          * Clear any exception: we're returning a bad status anyway. If
 874          * this call originated from Python, then the user gets an
 875          * appropriate creation error.
 876          */
 877         PyErr_Clear();
 878
 879 end:
 880         Py_XDECREF(py_comp_cls);
 881         Py_XDECREF(py_iter_cls);
 882         Py_XDECREF(py_iter_ptr);
 883         Py_XDECREF(py_component_port_output_ptr);
 884         Py_XDECREF(py_init_method_result);
 885         Py_XDECREF(py_iter);
 886         return status;
 887 }
 888
 889 static bt_self_message_iterator_status
 890 bt_py3_component_class_source_message_iterator_init(
 891                 bt_self_message_iterator *self_message_iterator,
 892                 bt_self_component_source *self_component_source,
 893                 bt_self_component_port_output *self_component_port_output)
 894 {
 895         bt_self_component *self_component = bt_self_component_source_as_self_component(self_component_source);
 896         return bt_py3_component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
 897 }
 898
 899 static bt_self_message_iterator_status
 900 bt_py3_component_class_filter_message_iterator_init(
 901                 bt_self_message_iterator *self_message_iterator,
 902                 bt_self_component_filter *self_component_filter,
 903                 bt_self_component_port_output *self_component_port_output)
 904 {
 905         bt_self_component *self_component = bt_self_component_filter_as_self_component(self_component_filter);
 906         return bt_py3_component_class_message_iterator_init(self_message_iterator, self_component, self_component_port_output);
 907 }
 908
 909 static void
 910 bt_py3_component_class_message_iterator_finalize(
 911                 bt_self_message_iterator *message_iterator)
 912 {
 913         PyObject *py_message_iter = bt_self_message_iterator_get_data(message_iterator);
 914         PyObject *py_method_result = NULL;
 915
 916         BT_ASSERT(py_message_iter);
 917
 918         /* Call user's _finalize() method */
 919         py_method_result = PyObject_CallMethod(py_message_iter,
 920                 "_finalize", NULL);
 921
 922         if (PyErr_Occurred()) {
 923                 BT_LOGW("User's _finalize() method raised an exception: ignoring.");
 924         }
 925
 926         /*
 927          * Ignore any exception raised by the _finalize() method because
 928          * it won't change anything at this point: the component is
 929          * being destroyed anyway.
 930          */
 931         PyErr_Clear();
 932         Py_XDECREF(py_method_result);
 933         Py_DECREF(py_message_iter);
 934 }
 935
 936 /* Valid for both sources and filters. */
 937
 938 static bt_self_message_iterator_status
 939 bt_py3_component_class_message_iterator_next(
 940                         bt_self_message_iterator *message_iterator,
 941                         bt_message_array_const msgs, uint64_t capacity,
 942                         uint64_t *count)
 943 {
 944         bt_self_message_iterator_status status = BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
 945         PyObject *py_message_iter = bt_self_message_iterator_get_data(message_iterator);
 946         PyObject *py_method_result = NULL;
 947
 948         BT_ASSERT(py_message_iter);
 949         py_method_result = PyObject_CallMethod(py_message_iter,
 950                 "_next_from_native", NULL);
 951         if (!py_method_result) {
 952                 status = bt_py3_exc_to_self_message_iterator_status();
 953                 BT_ASSERT(status != BT_SELF_MESSAGE_ITERATOR_STATUS_OK);
 954                 goto end;
 955         }
 956
 957         /*
 958          * The returned object, on success, is an integer object
 959          * (PyLong) containing the address of a native message
 960          * object (which is now ours).
 961          */
 962         msgs[0] = PyLong_AsVoidPtr(py_method_result);
 963         *count = 1;
 964
 965         /* Clear potential overflow error; should never happen */
 966         BT_ASSERT(!PyErr_Occurred());
 967         goto end;
 968
 969 end:
 970         Py_XDECREF(py_method_result);
 971         return status;
 972 }
 973
 974 static bt_self_component_status
 975 bt_py3_component_class_sink_consume(bt_self_component_sink *self_component_sink)
 976 {
 977         bt_self_component *self_component = bt_self_component_sink_as_self_component(self_component_sink);
 978         PyObject *py_comp = bt_self_component_get_data(self_component);
 979         PyObject *py_method_result = NULL;
 980         bt_self_component_status status;
 981
 982         BT_ASSERT(py_comp);
 983         py_method_result = PyObject_CallMethod(py_comp,
 984                 "_consume", NULL);
 985
 986         status = bt_py3_exc_to_self_component_status();
 987         if (!py_method_result && status == BT_SELF_COMPONENT_STATUS_OK) {
 988                 /* Pretty sure this should never happen, but just in case */
 989                 BT_LOGE("User's _consume() method failed without raising an exception: "
 990                         "status=%d", status);
 991                 status = BT_SELF_COMPONENT_STATUS_ERROR;
 992         }
 993
 994         Py_XDECREF(py_method_result);
 995         return status;
 996 }
 997
 998 static
 999 int bt_py3_component_class_set_help_and_desc(
1000                 bt_component_class *component_class,
1001                 const char *description, const char *help)
1002 {
1003         int ret;
1004
1005         if (description) {
1006                 ret = bt_component_class_set_description(component_class, description);
1007                 if (ret) {
1008                         BT_LOGE("Cannot set component class's description: "
1009                                 "comp-cls-addr=%p", component_class);
1010                         goto end;
1011                 }
1012         }
1013
1014         if (help) {
1015                 ret = bt_component_class_set_help(component_class, help);
1016                 if (ret) {
1017                         BT_LOGE("Cannot set component class's help text: "
1018                                 "comp-cls-addr=%p", component_class);
1019                         goto end;
1020                 }
1021         }
1022
1023         ret = 0;
1024
1025 end:
1026         return ret;
1027 }
1028
1029 static
1030 bt_component_class_source *bt_py3_component_class_source_create(
1031                 PyObject *py_cls, const char *name, const char *description,
1032                 const char *help)
1033 {
1034         bt_component_class_source *component_class_source;
1035         bt_component_class *component_class;
1036         int ret;
1037
1038         BT_ASSERT(py_cls);
1039
1040         component_class_source = bt_component_class_source_create(name,
1041                 bt_py3_component_class_message_iterator_next);
1042         if (!component_class_source) {
1043                 BT_LOGE_STR("Cannot create source component class.");
1044                 goto end;
1045         }
1046
1047         component_class = bt_component_class_source_as_component_class(component_class_source);
1048
1049         if (bt_py3_component_class_set_help_and_desc(component_class, description, help)) {
1050                 goto end;
1051         }
1052
1053         ret = bt_component_class_source_set_init_method(component_class_source, bt_py3_component_class_source_init);
1054         BT_ASSERT(ret == 0);
1055         ret = bt_component_class_source_set_finalize_method (component_class_source, bt_py3_component_class_source_finalize);
1056         BT_ASSERT(ret == 0);
1057         ret = bt_component_class_source_set_output_port_connected_method(component_class_source,
1058                 bt_py3_component_class_source_output_port_connected);
1059         BT_ASSERT(ret == 0);
1060         ret = bt_component_class_source_set_query_method(component_class_source, bt_py3_component_class_source_query);
1061         BT_ASSERT(ret == 0);
1062         ret = bt_component_class_source_set_message_iterator_init_method(
1063                 component_class_source, bt_py3_component_class_source_message_iterator_init);
1064         BT_ASSERT(ret == 0);
1065         ret = bt_component_class_source_set_message_iterator_finalize_method(
1066                 component_class_source, bt_py3_component_class_message_iterator_finalize);
1067         BT_ASSERT(ret == 0);
1068
1069         register_cc_ptr_to_py_cls(component_class, py_cls);
1070
1071 end:
1072         return component_class_source;
1073 }
1074
1075 static
1076 bt_component_class_filter *bt_py3_component_class_filter_create(
1077                 PyObject *py_cls, const char *name, const char *description,
1078                 const char *help)
1079 {
1080         bt_component_class *component_class;
1081         bt_component_class_filter *component_class_filter;
1082         int ret;
1083
1084         BT_ASSERT(py_cls);
1085
1086         component_class_filter = bt_component_class_filter_create(name,
1087                 bt_py3_component_class_message_iterator_next);
1088         if (!component_class_filter) {
1089                 BT_LOGE_STR("Cannot create filter component class.");
1090                 goto end;
1091         }
1092
1093         component_class = bt_component_class_filter_as_component_class(component_class_filter);
1094
1095         if (bt_py3_component_class_set_help_and_desc(component_class, description, help)) {
1096                 goto end;
1097         }
1098
1099         ret = bt_component_class_filter_set_init_method(component_class_filter, bt_py3_component_class_filter_init);
1100         BT_ASSERT(ret == 0);
1101         ret = bt_component_class_filter_set_finalize_method (component_class_filter, bt_py3_component_class_filter_finalize);
1102         BT_ASSERT(ret == 0);
1103         ret = bt_component_class_filter_set_input_port_connected_method(component_class_filter,
1104                 bt_py3_component_class_filter_input_port_connected);
1105         BT_ASSERT(ret == 0);
1106         ret = bt_component_class_filter_set_output_port_connected_method(component_class_filter,
1107                 bt_py3_component_class_filter_output_port_connected);
1108         BT_ASSERT(ret == 0);
1109         ret = bt_component_class_filter_set_query_method(component_class_filter, bt_py3_component_class_filter_query);
1110         BT_ASSERT(ret == 0);
1111         ret = bt_component_class_filter_set_message_iterator_init_method(
1112                 component_class_filter, bt_py3_component_class_filter_message_iterator_init);
1113         BT_ASSERT(ret == 0);
1114         ret = bt_component_class_filter_set_message_iterator_finalize_method(
1115                 component_class_filter, bt_py3_component_class_message_iterator_finalize);
1116         BT_ASSERT(ret == 0);
1117
1118         register_cc_ptr_to_py_cls(component_class, py_cls);
1119
1120 end:
1121         return component_class_filter;
1122 }
1123
1124 static
1125 bt_component_class_sink *bt_py3_component_class_sink_create(
1126                 PyObject *py_cls, const char *name, const char *description,
1127                 const char *help)
1128 {
1129         bt_component_class_sink *component_class_sink;
1130         bt_component_class *component_class;
1131         int ret;
1132
1133         BT_ASSERT(py_cls);
1134
1135         component_class_sink = bt_component_class_sink_create(name, bt_py3_component_class_sink_consume);
1136
1137         if (!component_class_sink) {
1138                 BT_LOGE_STR("Cannot create sink component class.");
1139                 goto end;
1140         }
1141
1142         component_class = bt_component_class_sink_as_component_class(component_class_sink);
1143
1144         if (bt_py3_component_class_set_help_and_desc(component_class, description, help)) {
1145                 goto end;
1146         }
1147
1148         ret = bt_component_class_sink_set_init_method(component_class_sink, bt_py3_component_class_sink_init);
1149         BT_ASSERT(ret == 0);
1150         ret = bt_component_class_sink_set_finalize_method(component_class_sink, bt_py3_component_class_sink_finalize);
1151         BT_ASSERT(ret == 0);
1152         ret = bt_component_class_sink_set_input_port_connected_method(component_class_sink,
1153                 bt_py3_component_class_sink_input_port_connected);
1154         BT_ASSERT(ret == 0);
1155         ret = bt_component_class_sink_set_graph_is_configured_method(component_class_sink,
1156                 bt_py3_component_class_sink_graph_is_configured);
1157         BT_ASSERT(ret == 0);
1158         ret = bt_component_class_sink_set_query_method(component_class_sink, bt_py3_component_class_sink_query);
1159         BT_ASSERT(ret == 0);
1160
1161         register_cc_ptr_to_py_cls(component_class, py_cls);
1162
1163 end:
1164         return component_class_sink;
1165 }
1166 %}
1167
1168 struct bt_component_class_source *bt_py3_component_class_source_create(
1169                 PyObject *py_cls, const char *name, const char *description,
1170                 const char *help);
1171 struct bt_component_class_filter *bt_py3_component_class_filter_create(
1172                 PyObject *py_cls, const char *name, const char *description,
1173                 const char *help);
1174 struct bt_component_class_sink *bt_py3_component_class_sink_create(
1175                 PyObject *py_cls, const char *name, const char *description,
1176                 const char *help);
1177 void bt_py3_cc_init_from_bt2(void);
1178 void bt_py3_cc_exit_handler(void);