src/lib/graph/iterator.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   5  * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   6  */
   7
   8 #define BT_LOG_TAG "LIB/MSG-ITER"
   9 #include "lib/logging.h"
  10
  11 #include "compat/compiler.h"
  12 #include "compat/glib.h"
  13 #include "lib/trace-ir/clock-class.h"
  14 #include "lib/trace-ir/clock-snapshot.h"
  15 #include <babeltrace2/trace-ir/field.h>
  16 #include <babeltrace2/trace-ir/event.h>
  17 #include "lib/trace-ir/event.h"
  18 #include <babeltrace2/trace-ir/packet.h>
  19 #include "lib/trace-ir/packet.h"
  20 #include "lib/trace-ir/stream.h"
  21 #include <babeltrace2/trace-ir/clock-class.h>
  22 #include <babeltrace2/trace-ir/stream-class.h>
  23 #include <babeltrace2/trace-ir/stream.h>
  24 #include <babeltrace2/graph/connection.h>
  25 #include <babeltrace2/graph/component.h>
  26 #include <babeltrace2/graph/message.h>
  27 #include <babeltrace2/graph/self-component.h>
  28 #include <babeltrace2/graph/port.h>
  29 #include <babeltrace2/graph/graph.h>
  30 #include <babeltrace2/graph/message-iterator.h>
  31 #include <babeltrace2/types.h>
  32 #include "common/assert.h"
  33 #include "lib/assert-pre.h"
  34 #include "lib/assert-post.h"
  35 #include <stdint.h>
  36 #include <inttypes.h>
  37 #include <stdbool.h>
  38 #include <stdlib.h>
  39
  40 #include "component-class.h"
  41 #include "component.h"
  42 #include "component-sink.h"
  43 #include "component-source.h"
  44 #include "connection.h"
  45 #include "graph.h"
  46 #include "message-iterator-class.h"
  47 #include "message/discarded-items.h"
  48 #include "message/event.h"
  49 #include "message/iterator.h"
  50 #include "message/message.h"
  51 #include "message/message-iterator-inactivity.h"
  52 #include "message/stream.h"
  53 #include "message/packet.h"
  54 #include "lib/func-status.h"
  55
  56 /*
  57  * TODO: Use graph's state (number of active iterators, etc.) and
  58  * possibly system specifications to make a better guess than this.
  59  */
  60 #define MSG_BATCH_SIZE  15
  61
  62 #define BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(_iter)                     \
  63         BT_ASSERT_PRE((_iter)->state == BT_MESSAGE_ITERATOR_STATE_ACTIVE || \
  64                 (_iter)->state == BT_MESSAGE_ITERATOR_STATE_ENDED || \
  65                 (_iter)->state == BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN || \
  66                 (_iter)->state == BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR, \
  67                 "Message iterator is in the wrong state: %!+i", _iter)
  68
  69 static inline
  70 void set_msg_iterator_state(struct bt_message_iterator *iterator,
  71                 enum bt_message_iterator_state state)
  72 {
  73         BT_ASSERT_DBG(iterator);
  74         BT_LIB_LOGD("Updating message iterator's state: new-state=%s",
  75                 bt_message_iterator_state_string(state));
  76         iterator->state = state;
  77 }
  78
  79 static
  80 void bt_message_iterator_destroy(struct bt_object *obj)
  81 {
  82         struct bt_message_iterator *iterator;
  83
  84         BT_ASSERT(obj);
  85
  86         /*
  87          * The message iterator's reference count is 0 if we're
  88          * here. Increment it to avoid a double-destroy (possibly
  89          * infinitely recursive). This could happen for example if the
  90          * message iterator's finalization function does
  91          * bt_object_get_ref() (or anything that causes
  92          * bt_object_get_ref() to be called) on itself (ref. count goes
  93          * from 0 to 1), and then bt_object_put_ref(): the reference
  94          * count would go from 1 to 0 again and this function would be
  95          * called again.
  96          */
  97         obj->ref_count++;
  98         iterator = (void *) obj;
  99         BT_LIB_LOGI("Destroying self component input port message iterator object: "
 100                 "%!+i", iterator);
 101         bt_message_iterator_try_finalize(iterator);
 102
 103         if (iterator->connection) {
 104                 /*
 105                  * Remove ourself from the originating connection so
 106                  * that it does not try to finalize a dangling pointer
 107                  * later.
 108                  */
 109                 bt_connection_remove_iterator(iterator->connection, iterator);
 110                 iterator->connection = NULL;
 111         }
 112
 113         if (iterator->auto_seek.msgs) {
 114                 while (!g_queue_is_empty(iterator->auto_seek.msgs)) {
 115                         bt_object_put_ref_no_null_check(
 116                                 g_queue_pop_tail(iterator->auto_seek.msgs));
 117                 }
 118
 119                 g_queue_free(iterator->auto_seek.msgs);
 120                 iterator->auto_seek.msgs = NULL;
 121         }
 122
 123         if (iterator->upstream_msg_iters) {
 124                 /*
 125                  * At this point the message iterator is finalized, so
 126                  * it's detached from any upstream message iterator.
 127                  */
 128                 BT_ASSERT(iterator->upstream_msg_iters->len == 0);
 129                 g_ptr_array_free(iterator->upstream_msg_iters, TRUE);
 130                 iterator->upstream_msg_iters = NULL;
 131         }
 132
 133         if (iterator->msgs) {
 134                 g_ptr_array_free(iterator->msgs, TRUE);
 135                 iterator->msgs = NULL;
 136         }
 137
 138         g_free(iterator);
 139 }
 140
 141 BT_HIDDEN
 142 void bt_message_iterator_try_finalize(
 143                 struct bt_message_iterator *iterator)
 144 {
 145         uint64_t i;
 146         bool call_user_finalize = true;
 147
 148         BT_ASSERT(iterator);
 149
 150         switch (iterator->state) {
 151         case BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED:
 152                 /*
 153                  * If this function is called while the iterator is in the
 154                  * NON_INITIALIZED state, it means the user initialization
 155                  * method has either not been called, or has failed.  We
 156                  * therefore don't want to call the user finalization method.
 157                  * However, the initialization method might have created some
 158                  * upstream message iterators before failing, so we want to
 159                  * execute the rest of this function, which unlinks the related
 160                  * iterators.
 161                  */
 162                 call_user_finalize = false;
 163                 break;
 164         case BT_MESSAGE_ITERATOR_STATE_FINALIZED:
 165                 /* Already finalized */
 166                 BT_LIB_LOGD("Not finalizing message iterator: already finalized: "
 167                         "%!+i", iterator);
 168                 goto end;
 169         case BT_MESSAGE_ITERATOR_STATE_FINALIZING:
 170                 /* Finalizing */
 171                 BT_LIB_LOGF("Message iterator is already being finalized: "
 172                         "%!+i", iterator);
 173                 bt_common_abort();
 174         default:
 175                 break;
 176         }
 177
 178         BT_LIB_LOGD("Finalizing message iterator: %!+i", iterator);
 179         set_msg_iterator_state(iterator,
 180                 BT_MESSAGE_ITERATOR_STATE_FINALIZING);
 181         BT_ASSERT(iterator->upstream_component);
 182
 183         /* Call user-defined destroy method */
 184         if (call_user_finalize) {
 185                 typedef void (*method_t)(void *);
 186                 method_t method;
 187                 struct bt_component_class *comp_class =
 188                         iterator->upstream_component->class;
 189                 struct bt_component_class_with_iterator_class *class_with_iter_class;
 190
 191                 BT_ASSERT(bt_component_class_has_message_iterator_class(comp_class));
 192                 class_with_iter_class = container_of(comp_class,
 193                         struct bt_component_class_with_iterator_class, parent);
 194                 method = (method_t) class_with_iter_class->msg_iter_cls->methods.finalize;
 195
 196                 if (method) {
 197                         const bt_error *saved_error;
 198
 199                         saved_error = bt_current_thread_take_error();
 200
 201                         BT_LIB_LOGD("Calling user's finalization method: %!+i",
 202                                 iterator);
 203                         method(iterator);
 204
 205                         if (saved_error) {
 206                                 BT_CURRENT_THREAD_MOVE_ERROR_AND_RESET(saved_error);
 207                         }
 208                 }
 209         }
 210
 211         /* Detach upstream message iterators */
 212         for (i = 0; i < iterator->upstream_msg_iters->len; i++) {
 213                 struct bt_message_iterator *upstream_msg_iter =
 214                         iterator->upstream_msg_iters->pdata[i];
 215
 216                 upstream_msg_iter->downstream_msg_iter = NULL;
 217         }
 218
 219         g_ptr_array_set_size(iterator->upstream_msg_iters, 0);
 220
 221         /* Detach downstream message iterator */
 222         if (iterator->downstream_msg_iter) {
 223                 gboolean existed;
 224
 225                 BT_ASSERT(iterator->downstream_msg_iter->upstream_msg_iters);
 226                 existed = g_ptr_array_remove_fast(
 227                         iterator->downstream_msg_iter->upstream_msg_iters,
 228                         iterator);
 229                 BT_ASSERT(existed);
 230         }
 231
 232         iterator->upstream_component = NULL;
 233         iterator->upstream_port = NULL;
 234         set_msg_iterator_state(iterator,
 235                 BT_MESSAGE_ITERATOR_STATE_FINALIZED);
 236         BT_LIB_LOGD("Finalized message iterator: %!+i", iterator);
 237
 238 end:
 239         return;
 240 }
 241
 242 BT_HIDDEN
 243 void bt_message_iterator_set_connection(
 244                 struct bt_message_iterator *iterator,
 245                 struct bt_connection *connection)
 246 {
 247         BT_ASSERT(iterator);
 248         iterator->connection = connection;
 249         BT_LIB_LOGI("Set message iterator's connection: "
 250                 "%![iter-]+i, %![conn-]+x", iterator, connection);
 251 }
 252
 253 static
 254 enum bt_message_iterator_can_seek_beginning_status can_seek_ns_from_origin_true(
 255                 struct bt_message_iterator *iterator,
 256                 int64_t ns_from_origin, bt_bool *can_seek)
 257 {
 258         *can_seek = BT_TRUE;
 259
 260         return BT_FUNC_STATUS_OK;
 261 }
 262
 263 static
 264 enum bt_message_iterator_can_seek_beginning_status can_seek_beginning_true(
 265                 struct bt_message_iterator *iterator,
 266                 bt_bool *can_seek)
 267 {
 268         *can_seek = BT_TRUE;
 269
 270         return BT_FUNC_STATUS_OK;
 271 }
 272
 273 static
 274 int create_self_component_input_port_message_iterator(
 275                 struct bt_self_message_iterator *self_downstream_msg_iter,
 276                 struct bt_self_component_port_input *self_port,
 277                 struct bt_message_iterator **message_iterator)
 278 {
 279         bt_message_iterator_class_initialize_method init_method = NULL;
 280         struct bt_message_iterator *iterator =
 281                 NULL;
 282         struct bt_message_iterator *downstream_msg_iter =
 283                 (void *) self_downstream_msg_iter;
 284         struct bt_port *port = (void *) self_port;
 285         struct bt_port *upstream_port;
 286         struct bt_component *comp;
 287         struct bt_component *upstream_comp;
 288         struct bt_component_class *upstream_comp_cls;
 289         struct bt_component_class_with_iterator_class *upstream_comp_cls_with_iter_cls;
 290         int status;
 291
 292         BT_ASSERT_PRE_NON_NULL(message_iterator, "Created message iterator");
 293         BT_ASSERT_PRE_NON_NULL(port, "Input port");
 294         comp = bt_port_borrow_component_inline(port);
 295         BT_ASSERT_PRE(bt_port_is_connected(port),
 296                 "Input port is not connected: %![port-]+p", port);
 297         BT_ASSERT_PRE(comp, "Input port is not part of a component: %![port-]+p",
 298                 port);
 299         BT_ASSERT(port->connection);
 300         upstream_port = port->connection->upstream_port;
 301         BT_ASSERT(upstream_port);
 302         upstream_comp = bt_port_borrow_component_inline(upstream_port);
 303         BT_ASSERT(upstream_comp);
 304         BT_ASSERT_PRE(
 305                 bt_component_borrow_graph(upstream_comp)->config_state ==
 306                         BT_GRAPH_CONFIGURATION_STATE_PARTIALLY_CONFIGURED ||
 307                 bt_component_borrow_graph(upstream_comp)->config_state ==
 308                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURED,
 309                 "Graph is not configured: %!+g",
 310                 bt_component_borrow_graph(upstream_comp));
 311         upstream_comp_cls = upstream_comp->class;
 312         BT_ASSERT(upstream_comp->class->type ==
 313                 BT_COMPONENT_CLASS_TYPE_SOURCE ||
 314                 upstream_comp->class->type ==
 315                 BT_COMPONENT_CLASS_TYPE_FILTER);
 316         BT_LIB_LOGI("Creating message iterator on self component input port: "
 317                 "%![up-comp-]+c, %![up-port-]+p", upstream_comp, upstream_port);
 318         iterator = g_new0(
 319                 struct bt_message_iterator, 1);
 320         if (!iterator) {
 321                 BT_LIB_LOGE_APPEND_CAUSE(
 322                         "Failed to allocate one self component input port "
 323                         "message iterator.");
 324                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 325                 goto error;
 326         }
 327
 328         bt_object_init_shared(&iterator->base,
 329                 bt_message_iterator_destroy);
 330         iterator->msgs = g_ptr_array_new();
 331         if (!iterator->msgs) {
 332                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray.");
 333                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 334                 goto error;
 335         }
 336
 337         g_ptr_array_set_size(iterator->msgs, MSG_BATCH_SIZE);
 338         iterator->last_ns_from_origin = INT64_MIN;
 339         iterator->auto_seek.msgs = g_queue_new();
 340         if (!iterator->auto_seek.msgs) {
 341                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GQueue.");
 342                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 343                 goto error;
 344         }
 345
 346         iterator->upstream_msg_iters = g_ptr_array_new();
 347         if (!iterator->upstream_msg_iters) {
 348                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray.");
 349                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 350                 goto error;
 351         }
 352
 353         iterator->upstream_component = upstream_comp;
 354         iterator->upstream_port = upstream_port;
 355         iterator->connection = iterator->upstream_port->connection;
 356         iterator->graph = bt_component_borrow_graph(upstream_comp);
 357         set_msg_iterator_state(iterator,
 358                 BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED);
 359
 360         /* Copy methods from the message iterator class to the message iterator. */
 361         BT_ASSERT(bt_component_class_has_message_iterator_class(upstream_comp_cls));
 362         upstream_comp_cls_with_iter_cls = container_of(upstream_comp_cls,
 363                 struct bt_component_class_with_iterator_class, parent);
 364
 365         iterator->methods.next =
 366                 (bt_message_iterator_next_method)
 367                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.next;
 368         iterator->methods.seek_ns_from_origin =
 369                 (bt_message_iterator_seek_ns_from_origin_method)
 370                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.seek_ns_from_origin;
 371         iterator->methods.seek_beginning =
 372                 (bt_message_iterator_seek_beginning_method)
 373                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.seek_beginning;
 374         iterator->methods.can_seek_ns_from_origin =
 375                 (bt_message_iterator_can_seek_ns_from_origin_method)
 376                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.can_seek_ns_from_origin;
 377         iterator->methods.can_seek_beginning =
 378                 (bt_message_iterator_can_seek_beginning_method)
 379                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.can_seek_beginning;
 380
 381         if (iterator->methods.seek_ns_from_origin &&
 382                         !iterator->methods.can_seek_ns_from_origin) {
 383                 iterator->methods.can_seek_ns_from_origin =
 384                         (bt_message_iterator_can_seek_ns_from_origin_method)
 385                                 can_seek_ns_from_origin_true;
 386         }
 387
 388         if (iterator->methods.seek_beginning &&
 389                         !iterator->methods.can_seek_beginning) {
 390                 iterator->methods.can_seek_beginning =
 391                         (bt_message_iterator_can_seek_beginning_method)
 392                                 can_seek_beginning_true;
 393         }
 394
 395         /* Call iterator's init method. */
 396         init_method = upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.initialize;
 397
 398         if (init_method) {
 399                 enum bt_message_iterator_class_initialize_method_status iter_status;
 400
 401                 BT_LIB_LOGD("Calling user's initialization method: %!+i", iterator);
 402                 iter_status = init_method(
 403                         (struct bt_self_message_iterator *) iterator,
 404                         &iterator->config,
 405                         (struct bt_self_component_port_output *) upstream_port);
 406                 BT_LOGD("User method returned: status=%s",
 407                         bt_common_func_status_string(iter_status));
 408                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(iter_status);
 409                 if (iter_status != BT_FUNC_STATUS_OK) {
 410                         BT_LIB_LOGW_APPEND_CAUSE(
 411                                 "Component input port message iterator initialization method failed: "
 412                                 "%![iter-]+i, status=%s",
 413                                 iterator,
 414                                 bt_common_func_status_string(iter_status));
 415                         status = iter_status;
 416                         goto error;
 417                 }
 418
 419                 iterator->config.frozen = true;
 420         }
 421
 422         if (downstream_msg_iter) {
 423                 /* Set this message iterator's downstream message iterator */
 424                 iterator->downstream_msg_iter = downstream_msg_iter;
 425
 426                 /*
 427                  * Add this message iterator to the downstream message
 428                  * iterator's array of upstream message iterators.
 429                  */
 430                 g_ptr_array_add(downstream_msg_iter->upstream_msg_iters,
 431                         iterator);
 432         }
 433
 434         set_msg_iterator_state(iterator,
 435                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
 436         g_ptr_array_add(port->connection->iterators, iterator);
 437         BT_LIB_LOGI("Created message iterator on self component input port: "
 438                 "%![up-port-]+p, %![up-comp-]+c, %![iter-]+i",
 439                 upstream_port, upstream_comp, iterator);
 440
 441         *message_iterator = iterator;
 442         status = BT_FUNC_STATUS_OK;
 443         goto end;
 444
 445 error:
 446         BT_OBJECT_PUT_REF_AND_RESET(iterator);
 447
 448 end:
 449         return status;
 450 }
 451
 452 bt_message_iterator_create_from_message_iterator_status
 453 bt_message_iterator_create_from_message_iterator(
 454                 struct bt_self_message_iterator *self_msg_iter,
 455                 struct bt_self_component_port_input *input_port,
 456                 struct bt_message_iterator **message_iterator)
 457 {
 458         BT_ASSERT_PRE_NO_ERROR();
 459         BT_ASSERT_PRE_NON_NULL(self_msg_iter, "Message iterator");
 460         return create_self_component_input_port_message_iterator(self_msg_iter,
 461                 input_port, message_iterator);
 462 }
 463
 464 bt_message_iterator_create_from_sink_component_status
 465 bt_message_iterator_create_from_sink_component(
 466                 struct bt_self_component_sink *self_comp,
 467                 struct bt_self_component_port_input *input_port,
 468                 struct bt_message_iterator **message_iterator)
 469 {
 470         BT_ASSERT_PRE_NO_ERROR();
 471         BT_ASSERT_PRE_NON_NULL(self_comp, "Sink component");
 472         return create_self_component_input_port_message_iterator(NULL,
 473                 input_port, message_iterator);
 474 }
 475
 476 void *bt_self_message_iterator_get_data(
 477                 const struct bt_self_message_iterator *self_iterator)
 478 {
 479         struct bt_message_iterator *iterator =
 480                 (void *) self_iterator;
 481
 482         BT_ASSERT_PRE_DEV_NON_NULL(iterator, "Message iterator");
 483         return iterator->user_data;
 484 }
 485
 486 void bt_self_message_iterator_set_data(
 487                 struct bt_self_message_iterator *self_iterator, void *data)
 488 {
 489         struct bt_message_iterator *iterator =
 490                 (void *) self_iterator;
 491
 492         BT_ASSERT_PRE_DEV_NON_NULL(iterator, "Message iterator");
 493         iterator->user_data = data;
 494         BT_LIB_LOGD("Set message iterator's user data: "
 495                 "%!+i, user-data-addr=%p", iterator, data);
 496 }
 497
 498 void bt_self_message_iterator_configuration_set_can_seek_forward(
 499                 bt_self_message_iterator_configuration *config,
 500                 bt_bool can_seek_forward)
 501 {
 502         BT_ASSERT_PRE_NON_NULL(config, "Message iterator configuration");
 503         BT_ASSERT_PRE_DEV_HOT(config, "Message iterator configuration", "");
 504
 505         config->can_seek_forward = can_seek_forward;
 506 }
 507
 508 /*
 509  * Validate that the default clock snapshot in `msg` doesn't make us go back in
 510  * time.
 511  */
 512
 513 BT_ASSERT_POST_DEV_FUNC
 514 static
 515 bool clock_snapshots_are_monotonic_one(
 516                 struct bt_message_iterator *iterator,
 517                 const bt_message *msg)
 518 {
 519         const struct bt_clock_snapshot *clock_snapshot = NULL;
 520         bt_message_type message_type = bt_message_get_type(msg);
 521         int64_t ns_from_origin;
 522         enum bt_clock_snapshot_get_ns_from_origin_status clock_snapshot_status;
 523
 524         /*
 525          * The default is true: if we can't figure out the clock snapshot
 526          * (or there is none), assume it is fine.
 527          */
 528         bool result = true;
 529
 530         switch (message_type) {
 531         case BT_MESSAGE_TYPE_EVENT:
 532         {
 533                 struct bt_message_event *event_msg = (struct bt_message_event *) msg;
 534                 clock_snapshot = event_msg->default_cs;
 535                 break;
 536         }
 537         case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
 538         {
 539                 struct bt_message_message_iterator_inactivity *inactivity_msg =
 540                         (struct bt_message_message_iterator_inactivity *) msg;
 541                 clock_snapshot = inactivity_msg->cs;
 542                 break;
 543         }
 544         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
 545         case BT_MESSAGE_TYPE_PACKET_END:
 546         {
 547                 struct bt_message_packet *packet_msg = (struct bt_message_packet *) msg;
 548                 clock_snapshot = packet_msg->default_cs;
 549                 break;
 550         }
 551         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
 552         case BT_MESSAGE_TYPE_STREAM_END:
 553         {
 554                 struct bt_message_stream *stream_msg = (struct bt_message_stream *) msg;
 555                 if (stream_msg->default_cs_state != BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
 556                         goto end;
 557                 }
 558
 559                 clock_snapshot = stream_msg->default_cs;
 560                 break;
 561         }
 562         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
 563         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
 564         {
 565                 struct bt_message_discarded_items *discarded_msg =
 566                         (struct bt_message_discarded_items *) msg;
 567
 568                 clock_snapshot = discarded_msg->default_begin_cs;
 569                 break;
 570         }
 571         }
 572
 573         if (!clock_snapshot) {
 574                 goto end;
 575         }
 576
 577         clock_snapshot_status = bt_clock_snapshot_get_ns_from_origin(
 578                 clock_snapshot, &ns_from_origin);
 579         if (clock_snapshot_status != BT_FUNC_STATUS_OK) {
 580                 /*
 581                  * bt_clock_snapshot_get_ns_from_origin can return
 582                  * OVERFLOW_ERROR.  We don't really want to report an error to
 583                  * our caller, so just clear it.
 584                  */
 585                 bt_current_thread_clear_error();
 586                 goto end;
 587         }
 588
 589         result = ns_from_origin >= iterator->last_ns_from_origin;
 590         iterator->last_ns_from_origin = ns_from_origin;
 591 end:
 592         return result;
 593 }
 594
 595 BT_ASSERT_POST_DEV_FUNC
 596 static
 597 bool clock_snapshots_are_monotonic(
 598                 struct bt_message_iterator *iterator,
 599                 bt_message_array_const msgs, uint64_t msg_count)
 600 {
 601         uint64_t i;
 602         bool result;
 603
 604         for (i = 0; i < msg_count; i++) {
 605                 if (!clock_snapshots_are_monotonic_one(iterator, msgs[i])) {
 606                         result = false;
 607                         goto end;
 608                 }
 609         }
 610
 611         result = true;
 612
 613 end:
 614         return result;
 615 }
 616
 617 /*
 618  * When a new stream begins, verify that the clock class tied to this
 619  * stream is compatible with what we've seen before.
 620  */
 621
 622 BT_ASSERT_POST_DEV_FUNC
 623 static
 624 bool clock_classes_are_compatible_one(struct bt_message_iterator *iterator,
 625                 const struct bt_message *msg)
 626 {
 627         enum bt_message_type message_type = bt_message_get_type(msg);
 628         bool result;
 629
 630         if (message_type == BT_MESSAGE_TYPE_STREAM_BEGINNING) {
 631                 const struct bt_message_stream *stream_msg = (struct bt_message_stream *) msg;
 632                 const struct bt_clock_class *clock_class = stream_msg->stream->class->default_clock_class;
 633                 bt_uuid clock_class_uuid = NULL;
 634
 635                 if (clock_class) {
 636                         clock_class_uuid = bt_clock_class_get_uuid(clock_class);
 637                 }
 638
 639                 switch (iterator->clock_expectation.type) {
 640                 case CLOCK_EXPECTATION_UNSET:
 641                         /*
 642                          * This is the first time we see a message with a clock
 643                          * snapshot: record the properties of that clock, against
 644                          * which we'll compare the clock properties of the following
 645                          * messages.
 646                          */
 647
 648                         if (!clock_class) {
 649                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_NONE;
 650                         } else if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 651                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_UNIX;
 652                         } else if (clock_class_uuid) {
 653                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_OTHER_UUID;
 654                                 bt_uuid_copy(iterator->clock_expectation.uuid, clock_class_uuid);
 655                         } else {
 656                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID;
 657                         }
 658                         break;
 659
 660                 case CLOCK_EXPECTATION_NONE:
 661                         if (clock_class) {
 662                                 BT_ASSERT_POST_DEV_MSG(
 663                                         "Expecting no clock class, got one: %![cc-]+K",
 664                                         clock_class);
 665                                 result = false;
 666                                 goto end;
 667                         }
 668
 669                         break;
 670
 671                 case CLOCK_EXPECTATION_ORIGIN_UNIX:
 672                         if (!clock_class) {
 673                                 BT_ASSERT_POST_DEV_MSG(
 674                                         "Expecting a clock class, got none.");
 675                                 result = false;
 676                                 goto end;
 677                         }
 678
 679                         if (!bt_clock_class_origin_is_unix_epoch(clock_class)) {
 680                                 BT_ASSERT_POST_DEV_MSG(
 681                                         "Expecting a clock class with Unix epoch origin: %![cc-]+K",
 682                                         clock_class);
 683                                 result = false;
 684                                 goto end;
 685                         }
 686                         break;
 687
 688                 case CLOCK_EXPECTATION_ORIGIN_OTHER_UUID:
 689                         if (!clock_class) {
 690                                 BT_ASSERT_POST_DEV_MSG(
 691                                         "Expecting a clock class, got none.");
 692                                 result = false;
 693                                 goto end;
 694                         }
 695
 696                         if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 697                                 BT_ASSERT_POST_DEV_MSG(
 698                                         "Expecting a clock class without Unix epoch origin: %![cc-]+K",
 699                                         clock_class);
 700                                 result = false;
 701                                 goto end;
 702                         }
 703
 704                         if (!clock_class_uuid) {
 705                                 BT_ASSERT_POST_DEV_MSG(
 706                                         "Expecting a clock class with UUID: %![cc-]+K",
 707                                         clock_class);
 708                                 result = false;
 709                                 goto end;
 710                         }
 711
 712                         if (bt_uuid_compare(iterator->clock_expectation.uuid, clock_class_uuid)) {
 713                                 BT_ASSERT_POST_DEV_MSG(
 714                                         "Expecting a clock class with UUID, got one "
 715                                         "with a different UUID: %![cc-]+K, expected-uuid=%!u",
 716                                         clock_class, iterator->clock_expectation.uuid);
 717                                 result = false;
 718                                 goto end;
 719                         }
 720                         break;
 721
 722                 case CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID:
 723                         if (!clock_class) {
 724                                 BT_ASSERT_POST_DEV_MSG(
 725                                         "Expecting a clock class, got none.");
 726                                 result = false;
 727                                 goto end;
 728                         }
 729
 730                         if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 731                                 BT_ASSERT_POST_DEV_MSG(
 732                                         "Expecting a clock class without Unix epoch origin: %![cc-]+K",
 733                                         clock_class);
 734                                 result = false;
 735                                 goto end;
 736                         }
 737
 738                         if (clock_class_uuid) {
 739                                 BT_ASSERT_POST_DEV_MSG(
 740                                         "Expecting a clock class without UUID: %![cc-]+K",
 741                                         clock_class);
 742                                 result = false;
 743                                 goto end;
 744                         }
 745                         break;
 746                 }
 747         }
 748
 749         result = true;
 750
 751 end:
 752         return result;
 753 }
 754
 755 BT_ASSERT_POST_DEV_FUNC
 756 static
 757 bool clock_classes_are_compatible(
 758                 struct bt_message_iterator *iterator,
 759                 bt_message_array_const msgs, uint64_t msg_count)
 760 {
 761         uint64_t i;
 762         bool result;
 763
 764         for (i = 0; i < msg_count; i++) {
 765                 if (!clock_classes_are_compatible_one(iterator, msgs[i])) {
 766                         result = false;
 767                         goto end;
 768                 }
 769         }
 770
 771         result = true;
 772
 773 end:
 774         return result;
 775 }
 776
 777 /*
 778  * Call the `next` method of the iterator.  Do some validation on the returned
 779  * messages.
 780  */
 781
 782 static
 783 enum bt_message_iterator_class_next_method_status
 784 call_iterator_next_method(
 785                 struct bt_message_iterator *iterator,
 786                 bt_message_array_const msgs, uint64_t capacity, uint64_t *user_count)
 787 {
 788         enum bt_message_iterator_class_next_method_status status;
 789
 790         BT_ASSERT_DBG(iterator->methods.next);
 791         BT_LOGD_STR("Calling user's \"next\" method.");
 792         status = iterator->methods.next(iterator, msgs, capacity, user_count);
 793         BT_LOGD("User method returned: status=%s, msg-count=%" PRIu64,
 794                 bt_common_func_status_string(status), *user_count);
 795
 796         if (status == BT_FUNC_STATUS_OK) {
 797                 BT_ASSERT_POST_DEV(clock_classes_are_compatible(iterator, msgs, *user_count),
 798                         "Clocks are not compatible");
 799                 BT_ASSERT_POST_DEV(clock_snapshots_are_monotonic(iterator, msgs, *user_count),
 800                         "Clock snapshots are not monotonic");
 801         }
 802
 803         BT_ASSERT_POST_DEV_NO_ERROR_IF_NO_ERROR_STATUS(status);
 804
 805         return status;
 806 }
 807
 808 enum bt_message_iterator_next_status
 809 bt_message_iterator_next(
 810                 struct bt_message_iterator *iterator,
 811                 bt_message_array_const *msgs, uint64_t *user_count)
 812 {
 813         enum bt_message_iterator_next_status status = BT_FUNC_STATUS_OK;
 814
 815         BT_ASSERT_PRE_DEV_NO_ERROR();
 816         BT_ASSERT_PRE_DEV_NON_NULL(iterator, "Message iterator");
 817         BT_ASSERT_PRE_DEV_NON_NULL(msgs, "Message array (output)");
 818         BT_ASSERT_PRE_DEV_NON_NULL(user_count, "Message count (output)");
 819         BT_ASSERT_PRE_DEV(iterator->state ==
 820                 BT_MESSAGE_ITERATOR_STATE_ACTIVE,
 821                 "Message iterator's \"next\" called, but "
 822                 "message iterator is in the wrong state: %!+i", iterator);
 823         BT_ASSERT_DBG(iterator->upstream_component);
 824         BT_ASSERT_DBG(iterator->upstream_component->class);
 825         BT_ASSERT_PRE_DEV(
 826                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
 827                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
 828                 "Graph is not configured: %!+g",
 829                 bt_component_borrow_graph(iterator->upstream_component));
 830         BT_LIB_LOGD("Getting next self component input port "
 831                 "message iterator's messages: %!+i, batch-size=%u",
 832                 iterator, MSG_BATCH_SIZE);
 833
 834         /*
 835          * Call the user's "next" method to get the next messages
 836          * and status.
 837          */
 838         *user_count = 0;
 839         status = (int) call_iterator_next_method(iterator,
 840                 (void *) iterator->msgs->pdata, MSG_BATCH_SIZE,
 841                 user_count);
 842         BT_LOGD("User method returned: status=%s, msg-count=%" PRIu64,
 843                 bt_common_func_status_string(status), *user_count);
 844         if (status < 0) {
 845                 BT_LIB_LOGW_APPEND_CAUSE(
 846                         "Component input port message iterator's \"next\" method failed: "
 847                         "%![iter-]+i, status=%s",
 848                         iterator, bt_common_func_status_string(status));
 849                 goto end;
 850         }
 851
 852         /*
 853          * There is no way that this iterator could have been finalized
 854          * during its "next" method, as the only way to do this is to
 855          * put the last iterator's reference, and this can only be done
 856          * by its downstream owner.
 857          *
 858          * For the same reason, there is no way that this iterator could
 859          * have seeked (cannot seek a self message iterator).
 860          */
 861         BT_ASSERT_DBG(iterator->state ==
 862                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
 863
 864         switch (status) {
 865         case BT_FUNC_STATUS_OK:
 866                 BT_ASSERT_POST_DEV(*user_count <= MSG_BATCH_SIZE,
 867                         "Invalid returned message count: greater than "
 868                         "batch size: count=%" PRIu64 ", batch-size=%u",
 869                         *user_count, MSG_BATCH_SIZE);
 870                 *msgs = (void *) iterator->msgs->pdata;
 871                 break;
 872         case BT_FUNC_STATUS_AGAIN:
 873                 goto end;
 874         case BT_FUNC_STATUS_END:
 875                 set_msg_iterator_state(iterator,
 876                         BT_MESSAGE_ITERATOR_STATE_ENDED);
 877                 goto end;
 878         default:
 879                 /* Unknown non-error status */
 880                 bt_common_abort();
 881         }
 882
 883 end:
 884         return status;
 885 }
 886
 887 struct bt_component *
 888 bt_message_iterator_borrow_component(
 889                 struct bt_message_iterator *iterator)
 890 {
 891         BT_ASSERT_PRE_DEV_NON_NULL(iterator, "Message iterator");
 892         return iterator->upstream_component;
 893 }
 894
 895 struct bt_self_component *bt_self_message_iterator_borrow_component(
 896                 struct bt_self_message_iterator *self_iterator)
 897 {
 898         struct bt_message_iterator *iterator =
 899                 (void *) self_iterator;
 900
 901         BT_ASSERT_PRE_DEV_NON_NULL(iterator, "Message iterator");
 902         return (void *) iterator->upstream_component;
 903 }
 904
 905 struct bt_self_component_port_output *bt_self_message_iterator_borrow_port(
 906                 struct bt_self_message_iterator *self_iterator)
 907 {
 908         struct bt_message_iterator *iterator =
 909                 (void *) self_iterator;
 910
 911         BT_ASSERT_PRE_DEV_NON_NULL(iterator, "Message iterator");
 912         return (void *) iterator->upstream_port;
 913 }
 914
 915 enum bt_message_iterator_can_seek_ns_from_origin_status
 916 bt_message_iterator_can_seek_ns_from_origin(
 917                 struct bt_message_iterator *iterator,
 918                 int64_t ns_from_origin, bt_bool *can_seek)
 919 {
 920         enum bt_message_iterator_can_seek_ns_from_origin_status status;
 921
 922         BT_ASSERT_PRE_NO_ERROR();
 923         BT_ASSERT_PRE_NON_NULL(iterator, "Message iterator");
 924         BT_ASSERT_PRE_NON_NULL(can_seek, "Result (output)");
 925         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
 926         BT_ASSERT_PRE(
 927                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
 928                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
 929                 "Graph is not configured: %!+g",
 930                 bt_component_borrow_graph(iterator->upstream_component));
 931
 932         if (iterator->methods.can_seek_ns_from_origin) {
 933                 /*
 934                  * Initialize to an invalid value, so we can post-assert that
 935                  * the method returned a valid value.
 936                  */
 937                 *can_seek = -1;
 938
 939                 BT_LIB_LOGD("Calling user's \"can seek nanoseconds from origin\" method: %!+i",
 940                         iterator);
 941
 942                 status = (int) iterator->methods.can_seek_ns_from_origin(iterator,
 943                         ns_from_origin, can_seek);
 944
 945                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(status);
 946
 947                 if (status != BT_FUNC_STATUS_OK) {
 948                         BT_LIB_LOGW_APPEND_CAUSE(
 949                                 "Component input port message iterator's \"can seek nanoseconds from origin\" method failed: "
 950                                 "%![iter-]+i, status=%s",
 951                                 iterator, bt_common_func_status_string(status));
 952                         goto end;
 953                 }
 954
 955                 BT_ASSERT_POST(*can_seek == BT_TRUE || *can_seek == BT_FALSE,
 956                         "Unexpected boolean value returned from user's \"can seek ns from origin\" method: val=%d, %![iter-]+i",
 957                         *can_seek, iterator);
 958
 959                 BT_LIB_LOGD(
 960                         "User's \"can seek nanoseconds from origin\" returned successfully: "
 961                         "%![iter-]+i, can-seek=%d",
 962                         iterator, *can_seek);
 963
 964                 if (*can_seek) {
 965                         goto end;
 966                 }
 967         }
 968
 969         /*
 970          * Automatic seeking fall back: if we can seek to the beginning and the
 971          * iterator supports forward seeking then we can automatically seek to
 972          * any timestamp.
 973          */
 974         status = (int) bt_message_iterator_can_seek_beginning(
 975                 iterator, can_seek);
 976         if (status != BT_FUNC_STATUS_OK) {
 977                 goto end;
 978         }
 979
 980         *can_seek = *can_seek && iterator->config.can_seek_forward;
 981
 982 end:
 983         return status;
 984 }
 985
 986 enum bt_message_iterator_can_seek_beginning_status
 987 bt_message_iterator_can_seek_beginning(
 988                 struct bt_message_iterator *iterator,
 989                 bt_bool *can_seek)
 990 {
 991         enum bt_message_iterator_can_seek_beginning_status status;
 992
 993         BT_ASSERT_PRE_NO_ERROR();
 994         BT_ASSERT_PRE_NON_NULL(iterator, "Message iterator");
 995         BT_ASSERT_PRE_NON_NULL(can_seek, "Result (output)");
 996         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
 997         BT_ASSERT_PRE(
 998                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
 999                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1000                 "Graph is not configured: %!+g",
1001                 bt_component_borrow_graph(iterator->upstream_component));
1002
1003         if (iterator->methods.can_seek_beginning) {
1004                 /*
1005                  * Initialize to an invalid value, so we can post-assert that
1006                  * the method returned a valid value.
1007                  */
1008                 *can_seek = -1;
1009
1010                 status = (int) iterator->methods.can_seek_beginning(iterator, can_seek);
1011
1012                 BT_ASSERT_POST(
1013                         status != BT_FUNC_STATUS_OK ||
1014                                 *can_seek == BT_TRUE ||
1015                                 *can_seek == BT_FALSE,
1016                         "Unexpected boolean value returned from user's \"can seek beginning\" method: val=%d, %![iter-]+i",
1017                         *can_seek, iterator);
1018                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(status);
1019         } else {
1020                 *can_seek = BT_FALSE;
1021                 status = BT_FUNC_STATUS_OK;
1022         }
1023
1024         return status;
1025 }
1026
1027 static inline
1028 void set_iterator_state_after_seeking(
1029                 struct bt_message_iterator *iterator,
1030                 int status)
1031 {
1032         enum bt_message_iterator_state new_state = 0;
1033
1034         /* Set iterator's state depending on seeking status */
1035         switch (status) {
1036         case BT_FUNC_STATUS_OK:
1037                 new_state = BT_MESSAGE_ITERATOR_STATE_ACTIVE;
1038                 break;
1039         case BT_FUNC_STATUS_AGAIN:
1040                 new_state = BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN;
1041                 break;
1042         case BT_FUNC_STATUS_ERROR:
1043         case BT_FUNC_STATUS_MEMORY_ERROR:
1044                 new_state = BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR;
1045                 break;
1046         case BT_FUNC_STATUS_END:
1047                 new_state = BT_MESSAGE_ITERATOR_STATE_ENDED;
1048                 break;
1049         default:
1050                 bt_common_abort();
1051         }
1052
1053         set_msg_iterator_state(iterator, new_state);
1054 }
1055
1056 static
1057 void reset_iterator_expectations(
1058                 struct bt_message_iterator *iterator)
1059 {
1060         iterator->last_ns_from_origin = INT64_MIN;
1061         iterator->clock_expectation.type = CLOCK_EXPECTATION_UNSET;
1062 }
1063
1064 static
1065 bool message_iterator_can_seek_beginning(
1066                 struct bt_message_iterator *iterator)
1067 {
1068         enum bt_message_iterator_can_seek_beginning_status status;
1069         bt_bool can_seek;
1070
1071         status = bt_message_iterator_can_seek_beginning(
1072                 iterator, &can_seek);
1073         if (status != BT_FUNC_STATUS_OK) {
1074                 can_seek = BT_FALSE;
1075         }
1076
1077         return can_seek;
1078 }
1079
1080 enum bt_message_iterator_seek_beginning_status
1081 bt_message_iterator_seek_beginning(
1082                 struct bt_message_iterator *iterator)
1083 {
1084         int status;
1085
1086         BT_ASSERT_PRE_NO_ERROR();
1087         BT_ASSERT_PRE_NON_NULL(iterator, "Message iterator");
1088         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1089         BT_ASSERT_PRE(
1090                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1091                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1092                 "Graph is not configured: %!+g",
1093                 bt_component_borrow_graph(iterator->upstream_component));
1094         BT_ASSERT_PRE(message_iterator_can_seek_beginning(iterator),
1095                 "Message iterator cannot seek beginning: %!+i", iterator);
1096
1097         /*
1098          * We are seeking, reset our expectations about how the following
1099          * messages should look like.
1100          */
1101         reset_iterator_expectations(iterator);
1102
1103         BT_LIB_LOGD("Calling user's \"seek beginning\" method: %!+i", iterator);
1104         set_msg_iterator_state(iterator,
1105                 BT_MESSAGE_ITERATOR_STATE_SEEKING);
1106         status = iterator->methods.seek_beginning(iterator);
1107         BT_LOGD("User method returned: status=%s",
1108                 bt_common_func_status_string(status));
1109         BT_ASSERT_POST(status == BT_FUNC_STATUS_OK ||
1110                 status == BT_FUNC_STATUS_ERROR ||
1111                 status == BT_FUNC_STATUS_MEMORY_ERROR ||
1112                 status == BT_FUNC_STATUS_AGAIN,
1113                 "Unexpected status: %![iter-]+i, status=%s",
1114                 iterator, bt_common_func_status_string(status));
1115         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(status);
1116         if (status < 0) {
1117                 BT_LIB_LOGW_APPEND_CAUSE(
1118                         "Component input port message iterator's \"seek beginning\" method failed: "
1119                         "%![iter-]+i, status=%s",
1120                         iterator, bt_common_func_status_string(status));
1121         }
1122
1123         set_iterator_state_after_seeking(iterator, status);
1124         return status;
1125 }
1126
1127 bt_bool
1128 bt_message_iterator_can_seek_forward(
1129                 bt_message_iterator *iterator)
1130 {
1131         BT_ASSERT_PRE_NON_NULL(iterator, "Message iterator");
1132
1133         return iterator->config.can_seek_forward;
1134 }
1135
1136 /*
1137  * Structure used to record the state of a given stream during the fast-forward
1138  * phase of an auto-seek.
1139  */
1140 struct auto_seek_stream_state {
1141         /*
1142          * Value representing which step of this timeline we are at.
1143          *
1144          *      time --->
1145          *   [SB]  1  [PB]  2  [PE]  1  [SE]
1146          *
1147          * At each point in the timeline, the messages we need to replicate are:
1148          *
1149          *   1: Stream beginning
1150          *   2: Stream beginning, packet beginning
1151          *
1152          * Before "Stream beginning" and after "Stream end", we don't need to
1153          * replicate anything as the stream doesn't exist.
1154          */
1155         enum {
1156                 AUTO_SEEK_STREAM_STATE_STREAM_BEGAN,
1157                 AUTO_SEEK_STREAM_STATE_PACKET_BEGAN,
1158         } state;
1159
1160         /*
1161          * If `state` is AUTO_SEEK_STREAM_STATE_PACKET_BEGAN, the packet we are
1162          * in.  This is a weak reference, since the packet will always be
1163          * alive by the time we use it.
1164          */
1165         struct bt_packet *packet;
1166
1167         /* Have we see a message with a clock snapshot yet? */
1168         bool seen_clock_snapshot;
1169 };
1170
1171 static
1172 struct auto_seek_stream_state *create_auto_seek_stream_state(void)
1173 {
1174         return g_new0(struct auto_seek_stream_state, 1);
1175 }
1176
1177 static
1178 void destroy_auto_seek_stream_state(void *ptr)
1179 {
1180         g_free(ptr);
1181 }
1182
1183 static
1184 GHashTable *create_auto_seek_stream_states(void)
1185 {
1186         return g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL,
1187                 destroy_auto_seek_stream_state);
1188 }
1189
1190 static
1191 void destroy_auto_seek_stream_states(GHashTable *stream_states)
1192 {
1193         g_hash_table_destroy(stream_states);
1194 }
1195
1196 /*
1197  * Handle one message while we are in the fast-forward phase of an auto-seek.
1198  *
1199  * Sets `*got_first` to true if the message's timestamp is greater or equal to
1200  * `ns_from_origin`.  In other words, if this is the first message after our
1201  * seek point.
1202  *
1203  * `stream_states` is an hash table of `bt_stream *` (weak reference) to
1204  * `struct auto_seek_stream_state` used to keep the state of each stream
1205  * during the fast-forward.
1206  */
1207
1208 static inline
1209 int auto_seek_handle_message(
1210                 struct bt_message_iterator *iterator,
1211                 int64_t ns_from_origin, const struct bt_message *msg,
1212                 bool *got_first, GHashTable *stream_states)
1213 {
1214         int status = BT_FUNC_STATUS_OK;
1215         int64_t msg_ns_from_origin;
1216         const struct bt_clock_snapshot *clk_snapshot = NULL;
1217         int ret;
1218
1219         BT_ASSERT_DBG(msg);
1220         BT_ASSERT_DBG(got_first);
1221
1222         switch (msg->type) {
1223         case BT_MESSAGE_TYPE_EVENT:
1224         {
1225                 const struct bt_message_event *event_msg =
1226                         (const void *) msg;
1227
1228                 clk_snapshot = event_msg->default_cs;
1229                 BT_ASSERT_POST_DEV(clk_snapshot,
1230                         "Event message has no default clock snapshot: %!+n",
1231                         event_msg);
1232                 break;
1233         }
1234         case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
1235         {
1236                 const struct bt_message_message_iterator_inactivity *inactivity_msg =
1237                         (const void *) msg;
1238
1239                 clk_snapshot = inactivity_msg->cs;
1240                 BT_ASSERT_DBG(clk_snapshot);
1241                 break;
1242         }
1243         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
1244         case BT_MESSAGE_TYPE_PACKET_END:
1245         {
1246                 const struct bt_message_packet *packet_msg =
1247                         (const void *) msg;
1248
1249                 clk_snapshot = packet_msg->default_cs;
1250                 BT_ASSERT_POST_DEV(clk_snapshot,
1251                         "Packet message has no default clock snapshot: %!+n",
1252                         packet_msg);
1253                 break;
1254         }
1255         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
1256         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
1257         {
1258                 struct bt_message_discarded_items *msg_disc_items =
1259                         (void *) msg;
1260
1261                 BT_ASSERT_POST_DEV(msg_disc_items->default_begin_cs &&
1262                         msg_disc_items->default_end_cs,
1263                         "Discarded events/packets message has no default clock snapshots: %!+n",
1264                         msg_disc_items);
1265                 ret = bt_clock_snapshot_get_ns_from_origin(
1266                         msg_disc_items->default_begin_cs,
1267                         &msg_ns_from_origin);
1268                 if (ret) {
1269                         status = BT_FUNC_STATUS_ERROR;
1270                         goto end;
1271                 }
1272
1273                 if (msg_ns_from_origin >= ns_from_origin) {
1274                         *got_first = true;
1275                         goto push_msg;
1276                 }
1277
1278                 ret = bt_clock_snapshot_get_ns_from_origin(
1279                         msg_disc_items->default_end_cs,
1280                         &msg_ns_from_origin);
1281                 if (ret) {
1282                         status = BT_FUNC_STATUS_ERROR;
1283                         goto end;
1284                 }
1285
1286                 if (msg_ns_from_origin >= ns_from_origin) {
1287                         /*
1288                          * The discarded items message's beginning time
1289                          * is before the requested seeking time, but its
1290                          * end time is after. Modify the message so as
1291                          * to set its beginning time to the requested
1292                          * seeking time, and make its item count unknown
1293                          * as we don't know if items were really
1294                          * discarded within the new time range.
1295                          */
1296                         uint64_t new_begin_raw_value = 0;
1297
1298                         ret = bt_clock_class_clock_value_from_ns_from_origin(
1299                                 msg_disc_items->default_end_cs->clock_class,
1300                                 ns_from_origin, &new_begin_raw_value);
1301                         if (ret) {
1302                                 status = BT_FUNC_STATUS_ERROR;
1303                                 goto end;
1304                         }
1305
1306                         bt_clock_snapshot_set_raw_value(
1307                                 msg_disc_items->default_begin_cs,
1308                                 new_begin_raw_value);
1309                         msg_disc_items->count.base.avail =
1310                                 BT_PROPERTY_AVAILABILITY_NOT_AVAILABLE;
1311
1312                         /*
1313                          * It is safe to push it because its beginning
1314                          * time is exactly the requested seeking time.
1315                          */
1316                         goto push_msg;
1317                 } else {
1318                         goto skip_msg;
1319                 }
1320         }
1321         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
1322         case BT_MESSAGE_TYPE_STREAM_END:
1323         {
1324                 struct bt_message_stream *stream_msg =
1325                         (struct bt_message_stream *) msg;
1326
1327                 if (stream_msg->default_cs_state != BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
1328                         /* Ignore */
1329                         goto skip_msg;
1330                 }
1331
1332                 clk_snapshot = stream_msg->default_cs;
1333                 break;
1334         }
1335         default:
1336                 bt_common_abort();
1337         }
1338
1339         BT_ASSERT_DBG(clk_snapshot);
1340         ret = bt_clock_snapshot_get_ns_from_origin(clk_snapshot,
1341                 &msg_ns_from_origin);
1342         if (ret) {
1343                 status = BT_FUNC_STATUS_ERROR;
1344                 goto end;
1345         }
1346
1347         if (msg_ns_from_origin >= ns_from_origin) {
1348                 *got_first = true;
1349                 goto push_msg;
1350         }
1351
1352 skip_msg:
1353         /* This message won't be sent downstream. */
1354         switch (msg->type) {
1355         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
1356         {
1357                 const struct bt_message_stream *stream_msg = (const void *) msg;
1358                 struct auto_seek_stream_state *stream_state;
1359
1360                 /* Update stream's state: stream began. */
1361                 stream_state = create_auto_seek_stream_state();
1362                 if (!stream_state) {
1363                         status = BT_FUNC_STATUS_MEMORY_ERROR;
1364                         goto end;
1365                 }
1366
1367                 stream_state->state = AUTO_SEEK_STREAM_STATE_STREAM_BEGAN;
1368
1369                 if (stream_msg->default_cs_state == BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
1370                         stream_state->seen_clock_snapshot = true;
1371                 }
1372
1373                 BT_ASSERT_DBG(!bt_g_hash_table_contains(stream_states, stream_msg->stream));
1374                 g_hash_table_insert(stream_states, stream_msg->stream, stream_state);
1375                 break;
1376         }
1377         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
1378         {
1379                 const struct bt_message_packet *packet_msg =
1380                         (const void *) msg;
1381                 struct auto_seek_stream_state *stream_state;
1382
1383                 /* Update stream's state: packet began. */
1384                 stream_state = g_hash_table_lookup(stream_states, packet_msg->packet->stream);
1385                 BT_ASSERT_DBG(stream_state);
1386                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_STREAM_BEGAN);
1387                 stream_state->state = AUTO_SEEK_STREAM_STATE_PACKET_BEGAN;
1388                 BT_ASSERT_DBG(!stream_state->packet);
1389                 stream_state->packet = packet_msg->packet;
1390
1391                 if (packet_msg->packet->stream->class->packets_have_beginning_default_clock_snapshot) {
1392                         stream_state->seen_clock_snapshot = true;
1393                 }
1394
1395                 break;
1396         }
1397         case BT_MESSAGE_TYPE_EVENT:
1398         {
1399                 const struct bt_message_event *event_msg = (const void *) msg;
1400                 struct auto_seek_stream_state *stream_state;
1401
1402                 stream_state = g_hash_table_lookup(stream_states,
1403                         event_msg->event->stream);
1404                 BT_ASSERT_DBG(stream_state);
1405
1406                 // HELPME: are we sure that event messages have clock snapshots at this point?
1407                 stream_state->seen_clock_snapshot = true;
1408
1409                 break;
1410         }
1411         case BT_MESSAGE_TYPE_PACKET_END:
1412         {
1413                 const struct bt_message_packet *packet_msg =
1414                         (const void *) msg;
1415                 struct auto_seek_stream_state *stream_state;
1416
1417                 /* Update stream's state: packet ended. */
1418                 stream_state = g_hash_table_lookup(stream_states, packet_msg->packet->stream);
1419                 BT_ASSERT_DBG(stream_state);
1420                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_PACKET_BEGAN);
1421                 stream_state->state = AUTO_SEEK_STREAM_STATE_STREAM_BEGAN;
1422                 BT_ASSERT_DBG(stream_state->packet);
1423                 stream_state->packet = NULL;
1424
1425                 if (packet_msg->packet->stream->class->packets_have_end_default_clock_snapshot) {
1426                         stream_state->seen_clock_snapshot = true;
1427                 }
1428
1429                 break;
1430         }
1431         case BT_MESSAGE_TYPE_STREAM_END:
1432         {
1433                 const struct bt_message_stream *stream_msg = (const void *) msg;
1434                 struct auto_seek_stream_state *stream_state;
1435
1436                 stream_state = g_hash_table_lookup(stream_states, stream_msg->stream);
1437                 BT_ASSERT_DBG(stream_state);
1438                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_STREAM_BEGAN);
1439                 BT_ASSERT_DBG(!stream_state->packet);
1440
1441                 /* Update stream's state: this stream doesn't exist anymore. */
1442                 g_hash_table_remove(stream_states, stream_msg->stream);
1443                 break;
1444         }
1445         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
1446         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
1447         {
1448                 const struct bt_message_discarded_items *discarded_msg =
1449                         (const void *) msg;
1450                 struct auto_seek_stream_state *stream_state;
1451
1452                 stream_state = g_hash_table_lookup(stream_states, discarded_msg->stream);
1453                 BT_ASSERT_DBG(stream_state);
1454
1455                 if ((msg->type == BT_MESSAGE_TYPE_DISCARDED_EVENTS && discarded_msg->stream->class->discarded_events_have_default_clock_snapshots) ||
1456                         (msg->type == BT_MESSAGE_TYPE_DISCARDED_PACKETS && discarded_msg->stream->class->discarded_packets_have_default_clock_snapshots)) {
1457                         stream_state->seen_clock_snapshot = true;
1458                 }
1459
1460                 break;
1461         }
1462         default:
1463                 break;
1464         }
1465
1466         bt_object_put_ref_no_null_check(msg);
1467         msg = NULL;
1468         goto end;
1469
1470 push_msg:
1471         g_queue_push_tail(iterator->auto_seek.msgs, (void *) msg);
1472         msg = NULL;
1473
1474 end:
1475         BT_ASSERT_DBG(!msg || status != BT_FUNC_STATUS_OK);
1476         return status;
1477 }
1478
1479 static
1480 int find_message_ge_ns_from_origin(
1481                 struct bt_message_iterator *iterator,
1482                 int64_t ns_from_origin, GHashTable *stream_states)
1483 {
1484         int status = BT_FUNC_STATUS_OK;
1485         enum bt_message_iterator_state init_state =
1486                 iterator->state;
1487         const struct bt_message *messages[MSG_BATCH_SIZE];
1488         uint64_t user_count = 0;
1489         uint64_t i;
1490         bool got_first = false;
1491
1492         BT_ASSERT_DBG(iterator);
1493         memset(&messages[0], 0, sizeof(messages[0]) * MSG_BATCH_SIZE);
1494
1495         /*
1496          * Make this iterator temporarily active (not seeking) to call
1497          * the "next" method.
1498          */
1499         set_msg_iterator_state(iterator,
1500                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
1501
1502         BT_ASSERT_DBG(iterator->methods.next);
1503
1504         while (!got_first) {
1505                 /*
1506                  * Call the user's "next" method to get the next
1507                  * messages and status.
1508                  */
1509                 status = call_iterator_next_method(iterator,
1510                         &messages[0], MSG_BATCH_SIZE, &user_count);
1511                 BT_LOGD("User method returned: status=%s",
1512                         bt_common_func_status_string(status));
1513                 if (status < 0) {
1514                         BT_LIB_LOGW_APPEND_CAUSE(
1515                                 "Component input port message iterator's \"next\" method failed: "
1516                                 "%![iter-]+i, status=%s",
1517                                 iterator, bt_common_func_status_string(status));
1518                 }
1519
1520                 /*
1521                  * The user's "next" method must not do any action which
1522                  * would change the iterator's state.
1523                  */
1524                 BT_ASSERT_DBG(iterator->state ==
1525                         BT_MESSAGE_ITERATOR_STATE_ACTIVE);
1526
1527                 switch (status) {
1528                 case BT_FUNC_STATUS_OK:
1529                         BT_ASSERT_POST_DEV(user_count <= MSG_BATCH_SIZE,
1530                                 "Invalid returned message count: greater than "
1531                                 "batch size: count=%" PRIu64 ", batch-size=%u",
1532                                 user_count, MSG_BATCH_SIZE);
1533                         break;
1534                 case BT_FUNC_STATUS_AGAIN:
1535                 case BT_FUNC_STATUS_ERROR:
1536                 case BT_FUNC_STATUS_MEMORY_ERROR:
1537                 case BT_FUNC_STATUS_END:
1538                         goto end;
1539                 default:
1540                         bt_common_abort();
1541                 }
1542
1543                 for (i = 0; i < user_count; i++) {
1544                         if (got_first) {
1545                                 g_queue_push_tail(iterator->auto_seek.msgs,
1546                                         (void *) messages[i]);
1547                                 messages[i] = NULL;
1548                                 continue;
1549                         }
1550
1551                         status = auto_seek_handle_message(iterator,
1552                                 ns_from_origin, messages[i], &got_first,
1553                                 stream_states);
1554                         if (status == BT_FUNC_STATUS_OK) {
1555                                 /* Message was either pushed or moved */
1556                                 messages[i] = NULL;
1557                         } else {
1558                                 goto end;
1559                         }
1560                 }
1561         }
1562
1563 end:
1564         for (i = 0; i < user_count; i++) {
1565                 if (messages[i]) {
1566                         bt_object_put_ref_no_null_check(messages[i]);
1567                 }
1568         }
1569
1570         set_msg_iterator_state(iterator, init_state);
1571         return status;
1572 }
1573
1574 /*
1575  * This function is installed as the iterator's next callback after we have
1576  * auto-seeked (seeked to the beginning and fast-forwarded) to send the
1577  * messages saved in iterator->auto_seek.msgs.  Once this is done, the original
1578  * next callback is put back.
1579  */
1580
1581 static
1582 enum bt_message_iterator_class_next_method_status post_auto_seek_next(
1583                 struct bt_message_iterator *iterator,
1584                 bt_message_array_const msgs, uint64_t capacity,
1585                 uint64_t *count)
1586 {
1587         BT_ASSERT(!g_queue_is_empty(iterator->auto_seek.msgs));
1588         *count = 0;
1589
1590         /*
1591          * Move auto-seek messages to the output array (which is this
1592          * iterator's base message array).
1593          */
1594         while (capacity > 0 && !g_queue_is_empty(iterator->auto_seek.msgs)) {
1595                 msgs[*count] = g_queue_pop_head(iterator->auto_seek.msgs);
1596                 capacity--;
1597                 (*count)++;
1598         }
1599
1600         BT_ASSERT(*count > 0);
1601
1602         if (g_queue_is_empty(iterator->auto_seek.msgs)) {
1603                 /* No more auto-seek messages, restore user's next callback. */
1604                 BT_ASSERT(iterator->auto_seek.original_next_callback);
1605                 iterator->methods.next = iterator->auto_seek.original_next_callback;
1606                 iterator->auto_seek.original_next_callback = NULL;
1607         }
1608
1609         return BT_FUNC_STATUS_OK;
1610 }
1611
1612 static inline
1613 int clock_raw_value_from_ns_from_origin(const bt_clock_class *clock_class,
1614                 int64_t ns_from_origin, uint64_t *raw_value)
1615 {
1616
1617         int64_t cc_offset_s = clock_class->offset_seconds;
1618         uint64_t cc_offset_cycles = clock_class->offset_cycles;
1619         uint64_t cc_freq = clock_class->frequency;
1620
1621         return bt_common_clock_value_from_ns_from_origin(cc_offset_s,
1622                 cc_offset_cycles, cc_freq, ns_from_origin, raw_value);
1623 }
1624
1625 static
1626 bool message_iterator_can_seek_ns_from_origin(
1627                 struct bt_message_iterator *iterator,
1628                 int64_t ns_from_origin)
1629 {
1630         enum bt_message_iterator_can_seek_ns_from_origin_status status;
1631         bt_bool can_seek;
1632
1633         status = bt_message_iterator_can_seek_ns_from_origin(
1634                 iterator, ns_from_origin, &can_seek);
1635         if (status != BT_FUNC_STATUS_OK) {
1636                 can_seek = BT_FALSE;
1637         }
1638
1639         return can_seek;
1640 }
1641
1642 enum bt_message_iterator_seek_ns_from_origin_status
1643 bt_message_iterator_seek_ns_from_origin(
1644                 struct bt_message_iterator *iterator,
1645                 int64_t ns_from_origin)
1646 {
1647         int status;
1648         GHashTable *stream_states = NULL;
1649         bt_bool can_seek_by_itself;
1650
1651         BT_ASSERT_PRE_NO_ERROR();
1652         BT_ASSERT_PRE_NON_NULL(iterator, "Message iterator");
1653         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1654         BT_ASSERT_PRE(
1655                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1656                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1657                 "Graph is not configured: %!+g",
1658                 bt_component_borrow_graph(iterator->upstream_component));
1659         /* The iterator must be able to seek ns from origin one way or another. */
1660         BT_ASSERT_PRE(
1661                 message_iterator_can_seek_ns_from_origin(iterator, ns_from_origin),
1662                 "Message iterator cannot seek nanoseconds from origin: %!+i, "
1663                 "ns-from-origin=%" PRId64, iterator, ns_from_origin);
1664         set_msg_iterator_state(iterator,
1665                 BT_MESSAGE_ITERATOR_STATE_SEEKING);
1666
1667         /*
1668          * We are seeking, reset our expectations about how the following
1669          * messages should look like.
1670          */
1671         reset_iterator_expectations(iterator);
1672
1673         /* Check if the iterator can seek by itself.  If not we'll use autoseek. */
1674         if (iterator->methods.can_seek_ns_from_origin) {
1675                 bt_message_iterator_class_can_seek_ns_from_origin_method_status
1676                         can_seek_status;
1677
1678                 can_seek_status =
1679                         iterator->methods.can_seek_ns_from_origin(
1680                                 iterator, ns_from_origin, &can_seek_by_itself);
1681                 if (can_seek_status != BT_FUNC_STATUS_OK) {
1682                         status = can_seek_status;
1683                         goto end;
1684                 }
1685         } else {
1686                 can_seek_by_itself = false;
1687         }
1688
1689         if (can_seek_by_itself) {
1690                 /* The iterator knows how to seek to a particular time, let it handle this. */
1691                 BT_ASSERT(iterator->methods.seek_ns_from_origin);
1692                 BT_LIB_LOGD("Calling user's \"seek nanoseconds from origin\" method: "
1693                         "%![iter-]+i, ns=%" PRId64, iterator, ns_from_origin);
1694                 status = iterator->methods.seek_ns_from_origin(iterator,
1695                         ns_from_origin);
1696                 BT_LOGD("User method returned: status=%s",
1697                         bt_common_func_status_string(status));
1698                 BT_ASSERT_POST(status == BT_FUNC_STATUS_OK ||
1699                         status == BT_FUNC_STATUS_ERROR ||
1700                         status == BT_FUNC_STATUS_MEMORY_ERROR ||
1701                         status == BT_FUNC_STATUS_AGAIN,
1702                         "Unexpected status: %![iter-]+i, status=%s",
1703                         iterator, bt_common_func_status_string(status));
1704                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(status);
1705                 if (status < 0) {
1706                         BT_LIB_LOGW_APPEND_CAUSE(
1707                                 "Component input port message iterator's \"seek nanoseconds from origin\" method failed: "
1708                                 "%![iter-]+i, status=%s",
1709                                 iterator, bt_common_func_status_string(status));
1710                 }
1711         } else {
1712                 /*
1713                  * The iterator doesn't know how to seek by itself to a
1714                  * particular time.  We will seek to the beginning and fast
1715                  * forward to the right place.
1716                  */
1717                 enum bt_message_iterator_class_can_seek_beginning_method_status can_seek_status;
1718                 bt_bool can_seek_beginning;
1719
1720                 can_seek_status = iterator->methods.can_seek_beginning(iterator,
1721                         &can_seek_beginning);
1722                 BT_ASSERT(can_seek_status == BT_FUNC_STATUS_OK);
1723                 BT_ASSERT(can_seek_beginning);
1724                 BT_ASSERT(iterator->methods.seek_beginning);
1725                 BT_LIB_LOGD("Calling user's \"seek beginning\" method: %!+i",
1726                         iterator);
1727                 status = iterator->methods.seek_beginning(iterator);
1728                 BT_LOGD("User method returned: status=%s",
1729                         bt_common_func_status_string(status));
1730                 BT_ASSERT_POST(status == BT_FUNC_STATUS_OK ||
1731                         status == BT_FUNC_STATUS_ERROR ||
1732                         status == BT_FUNC_STATUS_MEMORY_ERROR ||
1733                         status == BT_FUNC_STATUS_AGAIN,
1734                         "Unexpected status: %![iter-]+i, status=%s",
1735                         iterator, bt_common_func_status_string(status));
1736                 if (status < 0) {
1737                         BT_LIB_LOGW_APPEND_CAUSE(
1738                                 "Component input port message iterator's \"seek beginning\" method failed: "
1739                                 "%![iter-]+i, status=%s",
1740                                 iterator, bt_common_func_status_string(status));
1741                 }
1742
1743                 switch (status) {
1744                 case BT_FUNC_STATUS_OK:
1745                         break;
1746                 case BT_FUNC_STATUS_ERROR:
1747                 case BT_FUNC_STATUS_MEMORY_ERROR:
1748                 case BT_FUNC_STATUS_AGAIN:
1749                         goto end;
1750                 default:
1751                         bt_common_abort();
1752                 }
1753
1754                 /*
1755                  * Find the first message which has a default clock
1756                  * snapshot greater than or equal to the requested
1757                  * seeking time, and move the received messages from
1758                  * this point in the batch to this iterator's auto-seek
1759                  * message queue.
1760                  */
1761                 while (!g_queue_is_empty(iterator->auto_seek.msgs)) {
1762                         bt_object_put_ref_no_null_check(
1763                                 g_queue_pop_tail(iterator->auto_seek.msgs));
1764                 }
1765
1766                 stream_states = create_auto_seek_stream_states();
1767                 if (!stream_states) {
1768                         BT_LIB_LOGE_APPEND_CAUSE(
1769                                 "Failed to allocate one GHashTable.");
1770                         status = BT_FUNC_STATUS_MEMORY_ERROR;
1771                         goto end;
1772                 }
1773
1774                 status = find_message_ge_ns_from_origin(iterator,
1775                         ns_from_origin, stream_states);
1776                 switch (status) {
1777                 case BT_FUNC_STATUS_OK:
1778                 case BT_FUNC_STATUS_END:
1779                 {
1780                         GHashTableIter iter;
1781                         gpointer key, value;
1782
1783                         /*
1784                          * If some streams exist at the seek time, prepend the
1785                          * required messages to put those streams in the right
1786                          * state.
1787                          */
1788                         g_hash_table_iter_init(&iter, stream_states);
1789                         while (g_hash_table_iter_next (&iter, &key, &value)) {
1790                                 const bt_stream *stream = key;
1791                                 struct auto_seek_stream_state *stream_state =
1792                                         (struct auto_seek_stream_state *) value;
1793                                 bt_message *msg;
1794                                 const bt_clock_class *clock_class = bt_stream_class_borrow_default_clock_class_const(
1795                                         bt_stream_borrow_class_const(stream));
1796                                 /* Initialize to silence maybe-uninitialized warning. */
1797                                 uint64_t raw_value = 0;
1798
1799                                 /*
1800                                  * If we haven't seen a message with a clock snapshot, we don't know if our seek time is within
1801                                  * the clock's range, so it wouldn't be safe to try to convert ns_from_origin to a clock value.
1802                                  *
1803                                  * Also, it would be a bit of a lie to generate a stream begin message with the seek time as its
1804                                  * clock snapshot, because we don't really know if the stream existed at that time.  If we have
1805                                  * seen a message with a clock snapshot in our seeking, then we are sure that the
1806                                  * seek time is not below the clock range, and we know the stream was active at that
1807                                  * time (and that we cut it short).
1808                                  */
1809                                 if (stream_state->seen_clock_snapshot) {
1810                                         if (clock_raw_value_from_ns_from_origin(clock_class, ns_from_origin, &raw_value) != 0) {
1811                                                 BT_LIB_LOGW("Could not convert nanoseconds from origin to clock value: ns-from-origin=%" PRId64 ", %![cc-]+K",
1812                                                         ns_from_origin, clock_class);
1813                                                 status = BT_FUNC_STATUS_ERROR;
1814                                                 goto end;
1815                                         }
1816                                 }
1817
1818                                 switch (stream_state->state) {
1819                                 case AUTO_SEEK_STREAM_STATE_PACKET_BEGAN:
1820                                         BT_ASSERT(stream_state->packet);
1821                                         BT_LIB_LOGD("Creating packet message: %![packet-]+a", stream_state->packet);
1822
1823                                         if (stream->class->packets_have_beginning_default_clock_snapshot) {
1824                                                 /*
1825                                                  * If we are in the PACKET_BEGAN state, it means we have seen a "packet beginning"
1826                                                  * message.  If "packet beginning" packets have clock snapshots, then we must have
1827                                                  * seen a clock snapshot.
1828                                                  */
1829                                                 BT_ASSERT(stream_state->seen_clock_snapshot);
1830
1831                                                 msg = bt_message_packet_beginning_create_with_default_clock_snapshot(
1832                                                         (bt_self_message_iterator *) iterator, stream_state->packet, raw_value);
1833                                         } else {
1834                                                 msg = bt_message_packet_beginning_create((bt_self_message_iterator *) iterator,
1835                                                                 stream_state->packet);
1836                                         }
1837
1838                                         if (!msg) {
1839                                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
1840                                                 goto end;
1841                                         }
1842
1843                                         g_queue_push_head(iterator->auto_seek.msgs, msg);
1844                                         msg = NULL;
1845                                         /* fall-thru */
1846
1847                                 case AUTO_SEEK_STREAM_STATE_STREAM_BEGAN:
1848                                         msg = bt_message_stream_beginning_create(
1849                                                 (bt_self_message_iterator *) iterator, stream);
1850                                         if (!msg) {
1851                                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
1852                                                 goto end;
1853                                         }
1854
1855                                         if (stream_state->seen_clock_snapshot) {
1856                                                 bt_message_stream_beginning_set_default_clock_snapshot(msg, raw_value);
1857                                         }
1858
1859                                         g_queue_push_head(iterator->auto_seek.msgs, msg);
1860                                         msg = NULL;
1861                                         break;
1862                                 }
1863                         }
1864
1865                         /*
1866                          * If there are messages in the auto-seek
1867                          * message queue, replace the user's "next"
1868                          * method with a custom, temporary "next" method
1869                          * which returns them.
1870                          */
1871                         if (!g_queue_is_empty(iterator->auto_seek.msgs)) {
1872                                 BT_ASSERT(!iterator->auto_seek.original_next_callback);
1873                                 iterator->auto_seek.original_next_callback = iterator->methods.next;
1874
1875                                 iterator->methods.next =
1876                                         (bt_message_iterator_next_method)
1877                                                 post_auto_seek_next;
1878                         }
1879
1880                         /*
1881                          * `BT_FUNC_STATUS_END` becomes
1882                          * `BT_FUNC_STATUS_OK`: the next
1883                          * time this iterator's "next" method is called,
1884                          * it will return
1885                          * `BT_FUNC_STATUS_END`.
1886                          */
1887                         status = BT_FUNC_STATUS_OK;
1888                         break;
1889                 }
1890                 case BT_FUNC_STATUS_ERROR:
1891                 case BT_FUNC_STATUS_MEMORY_ERROR:
1892                 case BT_FUNC_STATUS_AGAIN:
1893                         goto end;
1894                 default:
1895                         bt_common_abort();
1896                 }
1897         }
1898
1899         /*
1900          * The following messages returned by the next method (including
1901          * post_auto_seek_next) must be after (or at) `ns_from_origin`.
1902          */
1903         iterator->last_ns_from_origin = ns_from_origin;
1904
1905 end:
1906         if (stream_states) {
1907                 destroy_auto_seek_stream_states(stream_states);
1908                 stream_states = NULL;
1909         }
1910
1911         set_iterator_state_after_seeking(iterator, status);
1912         return status;
1913 }
1914
1915 bt_bool bt_self_message_iterator_is_interrupted(
1916                 const struct bt_self_message_iterator *self_msg_iter)
1917 {
1918         const struct bt_message_iterator *iterator =
1919                 (const void *) self_msg_iter;
1920
1921         BT_ASSERT_PRE_NON_NULL(iterator, "Message iterator");
1922         return (bt_bool) bt_graph_is_interrupted(iterator->graph);
1923 }
1924
1925 void bt_message_iterator_get_ref(
1926                 const struct bt_message_iterator *iterator)
1927 {
1928         bt_object_get_ref(iterator);
1929 }
1930
1931 void bt_message_iterator_put_ref(
1932                 const struct bt_message_iterator *iterator)
1933 {
1934         bt_object_put_ref(iterator);
1935 }