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 b7646a1d57320d1edd4e1863f3d243816f160a55..6c3fe967e635ee05973a08c3d35dcdc027e9b64f 100644 (file)
--- a/include/babeltrace/babeltrace.h
+++ b/include/babeltrace/babeltrace.h
@@ -1,30 +1,105 @@
 #ifndef _BABELTRACE_H
 #define _BABELTRACE_H
 
-#include <stdio.h>
+/*
+ * BabelTrace API
+ *
+ * Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
 
-#define BABELTRACE_VERSION_MAJOR       0
-#define BABELTRACE_VERSION_MINOR       1
+/* Forward declarations */
+struct babeltrace_iter;
+struct trace_collection;
+struct ctf_stream_event;
+struct ctf_stream;
+struct babeltrace_saved_pos;
 
-extern int babeltrace_verbose, babeltrace_debug;
+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;
+};
 
-#define printf_verbose(fmt, args...)                           \
-       do {                                                    \
-               if (babeltrace_verbose)                         \
-                       printf("[verbose] " fmt, ## args);      \
-       } while (0)
+/*
+ * 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 trace_collection_pos *begin_pos,
+               struct trace_collection_pos *end_pos);
 
-#define printf_debug(fmt, args...)                             \
-       do {                                                    \
-               if (babeltrace_debug)                           \
-                       printf("[debug] " fmt, ## args);        \
-       } while (0)
+/*
+ * babeltrace_iter_destroy - Free a trace collection iterator.
+ */
+void babeltrace_iter_destroy(struct babeltrace_iter *iter);
 
-struct trace_descriptor;
+/*
+ * babeltrace_iter_next: Move trace collection position to the next event.
+ *
+ * Returns 0 on success, a negative value on error
+ */
+int babeltrace_iter_next(struct babeltrace_iter *iter);
 
-int convert_trace(struct trace_descriptor *td_write,
-                 struct trace_descriptor *td_read);
+/*
+ * 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.
+ */
+struct trace_collection_pos *
+       babeltrace_iter_save_pos(struct babeltrace_iter *iter);
 
-extern int opt_field_names;
+/*
+ * babeltrace_iter_free_pos - Free the position.
+ */
+void babeltrace_iter_free_pos(struct trace_collection_pos *pos);
 
-#endif
+/*
+ * babeltrace_iter_seek: seek iterator to given position.
+ *
+ * Return EOF if position is after the last event of the trace collection.
+ * Return other negative value for other errors.
+ * Return 0 for success.
+ */
+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.
+ *
+ * @iter: trace collection iterator (input)
+ * @stream: stream containing event at current position (output)
+ * @event: current event (output)
+ * Return 0 on success, negative error value on error.
+ */
+int babeltrace_iter_read_event(struct babeltrace_iter *iter,
+               struct ctf_stream **stream,
+               struct ctf_stream_event **event);
+
+#endif /* _BABELTRACE_H */