*
* Return 0 if the seek succeded, EOF if we didn't find any packet
* containing the timestamp, or a positive integer for error.
+ *
+ * TODO: this should be turned into a binary search! It is currently
+ * doing a linear search in the packets. This is a O(n) operation on a
+ * very frequent code path.
*/
static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
uint64_t timestamp)
return found ? 0 : EOF;
}
+/*
+ * Find timestamp of last event in the stream.
+ *
+ * Return value: 0 if OK, positive error value on error, EOF if no
+ * events were found.
+ */
+static int find_max_timestamp_ctf_file_stream(struct ctf_file_stream *cfs,
+ uint64_t *timestamp_end)
+{
+ int ret, count = 0, i;
+ uint64_t timestamp = 0;
+ struct ctf_stream_pos *stream_pos;
+
+ stream_pos = &cfs->pos;
+ /*
+ * We start by the last packet, and iterate backwards until we
+ * either find at least one event, or we reach the first packet
+ * (some packets can be empty).
+ */
+ for (i = stream_pos->packet_real_index->len - 1; i >= 0; i--) {
+ stream_pos->packet_seek(&stream_pos->parent, i, SEEK_SET);
+ count = 0;
+ /* read each event until we reach the end of the stream */
+ do {
+ ret = stream_read_event(cfs);
+ if (ret == 0) {
+ count++;
+ timestamp = cfs->parent.real_timestamp;
+ }
+ } while (ret == 0);
+
+ /* Error */
+ if (ret > 0)
+ goto end;
+ assert(ret == EOF);
+ if (count)
+ break;
+ }
+
+ if (count) {
+ *timestamp_end = timestamp;
+ ret = 0;
+ } else {
+ /* Return EOF if no events were found */
+ ret = EOF;
+ }
+end:
+ return ret;
+}
+
+/*
+ * Find the stream within a stream class that contains the event with
+ * the largest timestamp, and save that timestamp.
+ *
+ * Return 0 if OK, EOF if no events were found in the streams, or
+ * positive value on error.
+ */
+static int find_max_timestamp_ctf_stream_class(
+ struct ctf_stream_declaration *stream_class,
+ struct ctf_file_stream **cfsp,
+ uint64_t *max_timestamp)
+{
+ int ret = EOF, i;
+
+ for (i = 0; i < stream_class->streams->len; i++) {
+ struct ctf_stream_definition *stream;
+ struct ctf_file_stream *cfs;
+ uint64_t current_max_ts = 0;
+
+ stream = g_ptr_array_index(stream_class->streams, i);
+ if (!stream)
+ continue;
+ cfs = container_of(stream, struct ctf_file_stream, parent);
+ ret = find_max_timestamp_ctf_file_stream(cfs, ¤t_max_ts);
+ if (ret == EOF)
+ continue;
+ if (ret != 0)
+ break;
+ if (current_max_ts >= *max_timestamp) {
+ *max_timestamp = current_max_ts;
+ *cfsp = cfs;
+ }
+ }
+ assert(ret >= 0 || ret == EOF);
+ return ret;
+}
+
+/*
+ * seek_last_ctf_trace_collection: seek trace collection to last event.
+ *
+ * Return 0 if OK, EOF if no events were found, or positive error value
+ * on error.
+ */
+static int seek_last_ctf_trace_collection(struct trace_collection *tc,
+ struct ctf_file_stream **cfsp)
+{
+ int i, j, ret;
+ int found = 0;
+ uint64_t max_timestamp = 0;
+
+ if (!tc)
+ return 1;
+
+ /* For each trace in the trace_collection */
+ for (i = 0; i < tc->array->len; i++) {
+ struct ctf_trace *tin;
+ struct trace_descriptor *td_read;
+
+ td_read = g_ptr_array_index(tc->array, i);
+ if (!td_read)
+ continue;
+ tin = container_of(td_read, struct ctf_trace, parent);
+ /* For each stream_class in the trace */
+ for (j = 0; j < tin->streams->len; j++) {
+ struct ctf_stream_declaration *stream_class;
+
+ stream_class = g_ptr_array_index(tin->streams, j);
+ if (!stream_class)
+ continue;
+ ret = find_max_timestamp_ctf_stream_class(stream_class,
+ cfsp, &max_timestamp);
+ if (ret > 0)
+ goto end;
+ if (ret == 0)
+ found = 1;
+ assert(ret == EOF || ret == 0);
+ }
+ }
+ /*
+ * Now we know in which file stream the last event is located,
+ * and we know its timestamp.
+ */
+ if (!found) {
+ ret = EOF;
+ } else {
+ ret = seek_file_stream_by_timestamp(*cfsp, max_timestamp);
+ assert(ret == 0);
+ }
+end:
+ return ret;
+}
+
int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
{
struct trace_collection *tc;
}
}
break;
+ case BT_SEEK_LAST:
+ {
+ struct ctf_file_stream *cfs;
+
+ tc = iter->ctx->tc;
+ ret = seek_last_ctf_trace_collection(tc, &cfs);
+ if (ret != 0)
+ goto error;
+ /* remove all streams from the heap */
+ heap_free(iter->stream_heap);
+ /* Create a new empty heap */
+ ret = heap_init(iter->stream_heap, 0, stream_compare);
+ if (ret < 0)
+ goto error;
+ /* Insert the stream that contains the last event */
+ ret = heap_insert(iter->stream_heap, cfs);
+ if (ret)
+ goto error;
+ break;
+ }
default:
/* not implemented */
return -EINVAL;
projects / babeltrace.git / blobdiff