[lttng-dev] [BABELTRACE PATCH v2] Add BT_SEEK_LAST type to bt_iter_pos
Julien Desfossez
jdesfossez at efficios.com
Thu Aug 16 17:48:07 EDT 2012
From: Francis Deslauriers <francis.deslauriers at polymtl.ca>
Signed-off-by: Francis Deslauriers <francis.deslauriers at polymtl.ca>
Signed-off-by: Julien Desfossez <jdesfossez at efficios.com>
---
include/babeltrace/iterator.h | 1 +
lib/iterator.c | 207 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 208 insertions(+)
diff --git a/include/babeltrace/iterator.h b/include/babeltrace/iterator.h
index aa6470e..c8edbd1 100644
--- a/include/babeltrace/iterator.h
+++ b/include/babeltrace/iterator.h
@@ -48,6 +48,7 @@ struct bt_iter_pos {
BT_SEEK_CUR,
BT_SEEK_BEGIN,
BT_SEEK_END,
+ BT_SEEK_LAST
} type;
union {
uint64_t seek_time;
diff --git a/lib/iterator.c b/lib/iterator.c
index f5f413e..16b54bc 100644
--- a/lib/iterator.c
+++ b/lib/iterator.c
@@ -187,6 +187,193 @@ static int seek_ctf_trace_by_timestamp(struct ctf_trace *tin,
return found ? 0 : EOF;
}
+int seek_last_element_ctf_file_stream(struct trace_collection *tc,
+ struct ctf_file_stream **cfs, int max_packet,
+ int max_stream_id, int max_stream_class_id,
+ int max_trace_descriptor_id, uint64_t max_timestamp)
+{
+ struct trace_descriptor *max_td_read;
+ struct ctf_trace *max_tin;
+ struct ctf_stream_declaration *max_stream_class;
+ struct ctf_stream_definition *max_stream;
+ struct ctf_stream_pos *max_stream_pos;
+ int ret;
+
+ if (!tc)
+ return -EINVAL;
+
+ /* get the targeted trace descriptor */
+ max_td_read = g_ptr_array_index(tc->array, max_trace_descriptor_id);
+ max_tin = container_of(max_td_read, struct ctf_trace, parent);
+
+ /* get targeted stream class */
+ max_stream_class = g_ptr_array_index(max_tin->streams,
+ max_stream_class_id);
+ /* get targeted stream */
+ max_stream = g_ptr_array_index(max_stream_class->streams,
+ max_stream_id);
+ *cfs = container_of(max_stream, struct ctf_file_stream, parent);
+ max_stream_pos = &(*cfs)->pos;
+
+ /* we seek to the last packet of the stream. */
+ max_stream_pos->packet_seek(&max_stream_pos->parent,
+ max_packet, SEEK_SET);
+ /*
+ * iterate over all the event until we reach on that
+ * his timestamp correspond with the max saved previously.
+ */
+ do {
+ ret = stream_read_event(*cfs);
+ } while ((*cfs)->parent.real_timestamp != max_timestamp && ret == 0);
+
+ /* insert the stream in the heap */
+ return ret;
+}
+
+int find_last_event(struct ctf_file_stream *cfs, uint64_t *timestamp_end,
+ int *packet)
+{
+ struct ctf_stream_pos *stream_pos;
+ uint64_t tmp = 0;
+ int ret = 0;
+ int count = 0;
+ int event_read = 0;
+ int i;
+
+ if (!cfs)
+ return -EINVAL;
+
+ stream_pos = &cfs->pos;
+ /*
+ * we start by the last packet as the current one.
+ * If the current one is empty we go back one packet if possible.
+ */
+ 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 packet */
+ do {
+ tmp = cfs->parent.real_timestamp;
+ ret = stream_read_event(cfs);
+ count++;
+ } while (ret == 0);
+
+ if (count > 1)
+ event_read = 1;
+ /*
+ * Check if we have read at least one event before
+ * reaching the end of file.
+ */
+ if (ret == EOF && count > 1) {
+ *timestamp_end = tmp;
+ *packet = i;
+ break;
+ }
+ /* Error */
+ else if (ret > 0) {
+ return ret;
+ }
+ }
+
+ /* Check if we read at least one event on the stream */
+ if (!event_read) {
+ return 1;
+ }
+ return 0;
+}
+
+int find_max_timestamp_ctf_file_stream(
+ struct ctf_stream_declaration *stream_class, int *max_stream_id,
+ int *packet, uint64_t *max_timestamp, int *new_max)
+{
+ struct ctf_file_stream *cfs;
+ uint64_t savedtime;
+ int i;
+ int max_packet = 0;
+ int ret = 0;
+ int error = 1;
+
+ for (i = 0; i < stream_class->streams->len; i++) {
+ struct ctf_stream_definition *stream;
+
+ stream = g_ptr_array_index(stream_class->streams, i);
+ if (!stream)
+ continue;
+ cfs = container_of(stream, struct ctf_file_stream, parent);
+ ret = find_last_event(cfs, &savedtime, &max_packet);
+ /* Can return either EOF, 0, or error (> 0). */
+ if (ret == 0 && savedtime >= *max_timestamp) {
+ *new_max = 1;
+ *max_stream_id = i;
+ *packet = max_packet;
+ *max_timestamp = savedtime;
+ }
+ error = error & ret;
+ }
+
+ return error;
+}
+
+int seek_last_ctf_file_stream(struct trace_collection *tc,
+ struct ctf_file_stream **cfs)
+{
+ uint64_t max_timestamp = 0;
+ int i, j;
+ int ret;
+ int found = 0;
+ int new_max_found;
+ int max_packet;
+ int max_stream_id;
+ int max_stream_class_id;
+ int max_trace_descriptor_id;
+
+ if (!tc)
+ return -EINVAL;
+
+ /* 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;
+ /* For each file_stream in the stream_class */
+ new_max_found = 0;
+ ret = find_max_timestamp_ctf_file_stream(stream_class,
+ &max_stream_id, &max_packet,
+ &max_timestamp, &new_max_found);
+ if (!ret && new_max_found) {
+ found = 1;
+ max_trace_descriptor_id = i;
+ max_stream_class_id = j;
+ }
+ }
+ }
+ /*
+ * Now we know in which trace, stream_class and stream is the
+ * last event of the trace_collection.
+ * We can seek to this targeted event.
+ */
+ if (!found) {
+ ret = -1;
+ } else {
+ ret = seek_last_element_ctf_file_stream(tc, cfs, max_packet,
+ max_stream_id, max_stream_class_id,
+ max_trace_descriptor_id, max_timestamp);
+ }
+
+ return ret;
+}
+
int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
{
struct trace_collection *tc;
@@ -329,6 +516,26 @@ int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
}
}
break;
+ case BT_SEEK_LAST:
+ {
+ struct ctf_file_stream *cfs;
+
+ tc = iter->ctx->tc;
+ ret = seek_last_ctf_file_stream(tc, &cfs);
+ if (ret < 0)
+ goto error;
+
+ /* remove all stream 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.*/
+ heap_insert(iter->stream_heap, cfs);
+
+ return 0;
+ }
default:
/* not implemented */
return -EINVAL;
--
1.7.10.4
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