Enhance babeltrace API with position save/restore

[babeltrace.git] / include / babeltrace / babeltrace.h

diff --git a/include/babeltrace/babeltrace.h b/include/babeltrace/babeltrace.h
index dfe6112d0b9747e5c021fd9ceb1dd3231dcabbec..6c3fe967e635ee05973a08c3d35dcdc027e9b64f 100644 (file)
--- a/include/babeltrace/babeltrace.h
+++ b/include/babeltrace/babeltrace.h
@@ -22,11 +22,37 @@ struct babeltrace_iter;
 struct trace_collection;
 struct ctf_stream_event;
 struct ctf_stream;
 struct trace_collection;
 struct ctf_stream_event;
 struct ctf_stream;

+struct babeltrace_saved_pos;
+
+struct trace_collection_pos {
+       enum {
+               BT_SEEK_TIME,           /* uses u.seek_time */
+               BT_SEEK_RESTORE,        /* uses u.restore */
+               BT_SEEK_CUR,
+               BT_SEEK_BEGIN,
+               BT_SEEK_END,
+       } type;
+       union {
+               uint64_t seek_time;
+               struct babeltrace_saved_pos *restore;
+       } u;
+};

 
 /*
  * babeltrace_iter_create - Allocate a trace collection iterator.
 
 /*
  * babeltrace_iter_create - Allocate a trace collection iterator.

+ *
+ * begin_pos and end_pos are optional parameters to specify the position
+ * at which the trace collection should be seeked upon iterator
+ * creation, and the position at which iteration will start returning
+ * "EOF".
+ *
+ * By default, if begin_pos is NULL, a BT_SEEK_CUR is performed at
+ * creation. By default, if end_pos is NULL, a BT_SEEK_END (end of
+ * trace) is the EOF criterion.

  */
  */

-struct babeltrace_iter *babeltrace_iter_create(struct trace_collection *tc);
+struct babeltrace_iter *babeltrace_iter_create(struct trace_collection *tc,
+               struct trace_collection_pos *begin_pos,
+               struct trace_collection_pos *end_pos);

 
 /*
  * babeltrace_iter_destroy - Free a trace collection iterator.
 
 /*
  * babeltrace_iter_destroy - Free a trace collection iterator.


@@ -41,34 +67,28 @@ void babeltrace_iter_destroy(struct babeltrace_iter *iter);
 int babeltrace_iter_next(struct babeltrace_iter *iter);
 
 /*
 int babeltrace_iter_next(struct babeltrace_iter *iter);
 
 /*

- * babeltrace_iter_get_pos - Get the current trace collection position.
+ * babeltrace_iter_save_pos - Save the current trace collection position.

  *
  * The position returned by this function needs to be freed by
  * babeltrace_iter_free_pos after use.
  */
  *
  * The position returned by this function needs to be freed by
  * babeltrace_iter_free_pos after use.
  */

-struct babeltrace_iter_pos *
-       babeltrace_iter_get_pos(struct babeltrace_iter *iter);
+struct trace_collection_pos *
+       babeltrace_iter_save_pos(struct babeltrace_iter *iter);

 
 /*
  * babeltrace_iter_free_pos - Free the position.
  */
 
 /*
  * babeltrace_iter_free_pos - Free the position.
  */

-void babeltrace_iter_free_pos(struct babeltrace_iter_pos *pos);
-
-/*
- * babeltrace_iter_seek_pos - Seek the trace collection to the position.
- */
-int babeltrace_iter_seek_pos(struct babeltrace_iter *iter,
-               struct babeltrace_iter_pos *pos);
+void babeltrace_iter_free_pos(struct trace_collection_pos *pos);

 
 /*
 
 /*

- * babeltrace_iter_seek_time: Seek the trace collection to the given timestamp.
+ * babeltrace_iter_seek: seek iterator to given position.

  *
  *

- * Return EOF if timestamp is after the last event of the trace collection.
+ * Return EOF if position is after the last event of the trace collection.

  * Return other negative value for other errors.
  * Return 0 for success.
  */
  * Return other negative value for other errors.
  * Return 0 for success.
  */

-int babeltrace_iter_seek_time(struct babeltrace_iter *iter,
-               uint64_t timestamp);
+int babeltrace_iter_seek(struct babeltrace_iter *iter,
+               const struct trace_collection_pos *pos);

 
 /*
  * babeltrace_iter_read_event: Read the iterator's current event data.
 
 /*
  * babeltrace_iter_read_event: Read the iterator's current event data.