+ /*
+ * Turn on dry run mode to prevent the creation and usage of Babeltrace
+ * library objects (bt_field, bt_message_*, etc.).
+ */
+ bt_msg_iter_set_dry_run(msg_iter, true);
+
+ /* Seek to the beginning of the target packet. */
+ iter_status = bt_msg_iter_seek(ds_file->msg_iter, index_entry->offset);
+ if (iter_status) {
+ /* bt_msg_iter_seek() logs errors. */
+ ret = -1;
+ goto end;
+ }
+
+ switch (target_event) {
+ case FIRST_EVENT:
+ /*
+ * Start to decode the packet until we reach the end of
+ * the first event. To extract the first event's clock
+ * snapshot.
+ */
+ iter_status = bt_msg_iter_curr_packet_first_event_clock_snapshot(
+ ds_file->msg_iter, cs);
+ break;
+ case LAST_EVENT:
+ /* Decode the packet to extract the last event's clock snapshot. */
+ iter_status = bt_msg_iter_curr_packet_last_event_clock_snapshot(
+ ds_file->msg_iter, cs);
+ break;
+ default:
+ abort();
+ }
+ if (iter_status) {
+ ret = -1;
+ goto end;
+ }
+
+ /* Convert clock snapshot to timestamp. */
+ ret = bt_util_clock_cycles_to_ns_from_origin(*cs,
+ default_cc->frequency, default_cc->offset_seconds,
+ default_cc->offset_cycles, ts_ns);
+ if (ret) {
+ BT_COMP_LOGE_APPEND_CAUSE(self_comp,
+ "Failed to convert clock snapshot to timestamp");
+ goto end;
+ }
+
+end:
+ if (ds_file) {
+ ctf_fs_ds_file_destroy(ds_file);
+ }
+ if (msg_iter) {
+ bt_msg_iter_destroy(msg_iter);
+ }
+
+ return ret;
+}
+
+static
+int decode_packet_first_event_timestamp(struct ctf_fs_trace *ctf_fs_trace,
+ struct ctf_clock_class *default_cc,
+ struct ctf_fs_ds_index_entry *index_entry, uint64_t *cs, int64_t *ts_ns)
+{
+ return decode_clock_snapshot_after_event(ctf_fs_trace, default_cc,
+ index_entry, FIRST_EVENT, cs, ts_ns);
+}
+
+static
+int decode_packet_last_event_timestamp(struct ctf_fs_trace *ctf_fs_trace,
+ struct ctf_clock_class *default_cc,
+ struct ctf_fs_ds_index_entry *index_entry, uint64_t *cs, int64_t *ts_ns)
+{
+ return decode_clock_snapshot_after_event(ctf_fs_trace, default_cc,
+ index_entry, LAST_EVENT, cs, ts_ns);
+}
+
+/*
+ * Fix up packet index entries for lttng's "event-after-packet" bug.
+ * Some buggy lttng tracer versions may emit events with a timestamp that is
+ * larger (after) than the timestamp_end of the their packets.
+ *
+ * To fix up this erroneous data we do the following:
+ * 1. If it's not the stream file's last packet: set the packet index entry's
+ * end time to the next packet's beginning time.
+ * 2. If it's the stream file's last packet, set the packet index entry's end
+ * time to the packet's last event's time, if any, or to the packet's
+ * beginning time otherwise.
+ *
+ * Known buggy tracer versions:
+ * - before lttng-ust 2.11.0
+ * - before lttng-module 2.11.0
+ * - before lttng-module 2.10.10
+ * - before lttng-module 2.9.13
+ */
+static
+int fix_index_lttng_event_after_packet_bug(struct ctf_fs_trace *trace)
+{
+ int ret = 0;
+ guint ds_file_group_i;
+ GPtrArray *ds_file_groups = trace->ds_file_groups;
+ bt_logging_level log_level = trace->log_level;
+
+ for (ds_file_group_i = 0; ds_file_group_i < ds_file_groups->len;
+ ds_file_group_i++) {
+ guint entry_i;
+ struct ctf_clock_class *default_cc;
+ struct ctf_fs_ds_index_entry *last_entry;
+ struct ctf_fs_ds_index *index;
+
+ struct ctf_fs_ds_file_group *ds_file_group =
+ g_ptr_array_index(ds_file_groups, ds_file_group_i);
+
+ BT_ASSERT(ds_file_group);
+ index = ds_file_group->index;
+
+ BT_ASSERT(index);
+ BT_ASSERT(index->entries);
+ BT_ASSERT(index->entries->len > 0);
+
+ /*
+ * Iterate over all entries but the last one. The last one is
+ * fixed differently after.
+ */
+ for (entry_i = 0; entry_i < index->entries->len - 1;
+ entry_i++) {
+ struct ctf_fs_ds_index_entry *curr_entry, *next_entry;
+
+ curr_entry = g_ptr_array_index(index->entries, entry_i);
+ next_entry = g_ptr_array_index(index->entries, entry_i + 1);
+
+ /*
+ * 1. Set the current index entry `end` timestamp to
+ * the next index entry `begin` timestamp.
+ */
+ curr_entry->timestamp_end = next_entry->timestamp_begin;
+ curr_entry->timestamp_end_ns = next_entry->timestamp_begin_ns;
+ }
+
+ /*
+ * 2. Fix the last entry by decoding the last event of the last
+ * packet.
+ */
+ last_entry = g_ptr_array_index(index->entries,
+ index->entries->len - 1);
+ BT_ASSERT(last_entry);
+
+ BT_ASSERT(ds_file_group->sc->default_clock_class);
+ default_cc = ds_file_group->sc->default_clock_class;
+
+ /*
+ * Decode packet to read the timestamp of the last event of the
+ * entry.
+ */
+ ret = decode_packet_last_event_timestamp(trace, default_cc,
+ last_entry, &last_entry->timestamp_end,
+ &last_entry->timestamp_end_ns);
+ if (ret) {
+ BT_COMP_LOGE_APPEND_CAUSE(trace->self_comp,
+ "Failed to decode stream's last packet to get its last event's clock snapshot.");
+ goto end;
+ }
+ }
+
+end:
+ return ret;
+}
+
+/*
+ * Fix up packet index entries for barectf's "event-before-packet" bug.
+ * Some buggy barectf tracer versions may emit events with a timestamp that is
+ * less than the timestamp_begin of the their packets.
+ *
+ * To fix up this erroneous data we do the following:
+ * 1. Starting at the second index entry, set the timestamp_begin of the
+ * current entry to the timestamp of the first event of the packet.
+ * 2. Set the previous entry's timestamp_end to the timestamp_begin of the
+ * current packet.
+ *
+ * Known buggy tracer versions:
+ * - before barectf 2.3.1
+ */
+static
+int fix_index_barectf_event_before_packet_bug(struct ctf_fs_trace *trace)
+{
+ int ret = 0;
+ guint ds_file_group_i;
+ GPtrArray *ds_file_groups = trace->ds_file_groups;
+ bt_logging_level log_level = trace->log_level;
+
+ for (ds_file_group_i = 0; ds_file_group_i < ds_file_groups->len;
+ ds_file_group_i++) {
+ guint entry_i;
+ struct ctf_clock_class *default_cc;
+ struct ctf_fs_ds_file_group *ds_file_group =
+ g_ptr_array_index(ds_file_groups, ds_file_group_i);
+
+ struct ctf_fs_ds_index *index = ds_file_group->index;
+
+ BT_ASSERT(index);
+ BT_ASSERT(index->entries);
+ BT_ASSERT(index->entries->len > 0);
+
+ BT_ASSERT(ds_file_group->sc->default_clock_class);
+ default_cc = ds_file_group->sc->default_clock_class;
+
+ /*
+ * 1. Iterate over the index, starting from the second entry
+ * (index = 1).
+ */
+ for (entry_i = 1; entry_i < index->entries->len;
+ entry_i++) {
+ struct ctf_fs_ds_index_entry *curr_entry, *prev_entry;
+ prev_entry = g_ptr_array_index(index->entries, entry_i - 1);
+ curr_entry = g_ptr_array_index(index->entries, entry_i);
+ /*
+ * 2. Set the current entry `begin` timestamp to the
+ * timestamp of the first event of the current packet.
+ */
+ ret = decode_packet_first_event_timestamp(trace, default_cc,
+ curr_entry, &curr_entry->timestamp_begin,
+ &curr_entry->timestamp_begin_ns);
+ if (ret) {
+ BT_COMP_LOGE_APPEND_CAUSE(trace->self_comp,
+ "Failed to decode first event's clock snapshot");
+ goto end;