LTTng » Babeltrace

When implementing a tool iterating all events of a trace collection, being able to know where we are in this collection would be a nice-to-have, mainly for visual feedback.

The only way to do this currently is to rely on timestamps ((cur_ts - beg_ts) / (end_ts - beg_ts)), which of course is not accurate unless you have a fairly stable events/s rate.

I believe that total or partial event counts are not recorded anywhere in CTF, but the API in this case could use the current combined read positions in the trace files, e.g., for 3 traces:

size_t total_pos = pos(file1) + pos(file2) + pos(file3);
size_t total_size = size(file1) + size(file2) + size(file3);
double progress = (double) total_pos / (double) total_size;

Other formats such as lttng-live could always return 0 or -1.