[21/25] entry: show finer-grained counter in "Filtering content" progress line

Commit Message

Ævar Arnfjörð Bjarmason June 23, 2021, 5:48 p.m. UTC

From: SZEDER Gábor <[e-mail]>

The "Filtering content" progress in entry.c:finish_delayed_checkout()
is unusual because of how it calculates the progress count and because
it shows the progress of a nested loop.  It works basically like this:

  start_delayed_progress(p, nr_of_paths_to_filter)
  for_each_filter {
      display_progress(p, nr_of_paths_to_filter - nr_of_paths_still_left_to_filter)
      for_each_path_handled_by_the_current_filter {
          checkout_entry()
      }
  }
  stop_progress(p)

There are two issues with this approach:

  - The work done by the last filter (or the only filter if there is
    only one) is never counted, so if the last filter still has some
    paths to process, then the counter shown in the "done" progress
    line will not match the expected total.

    This would cause a BUG() in an upcoming change that adds an
    assertion checking if the "total" at the end matches the last
    progress bar update..

    This is because both use only one filter.  (The test 'delayed
    checkout in process filter' uses two filters but the first one
    does all the work, so that test already happens to succeed even
    with such an assertion.)

  - The progress counter is updated only once per filter, not once per
    processed path, so if a filter has a lot of paths to process, then
    the counter might stay unchanged for a long while and then make a
    big jump (though the user still gets a sense of progress, because
    we call display_throughput() after each processed path to show the
    amount of processed data).

Move the display_progress() call to the inner loop, right next to that
checkout_entry() call that does the hard work for each path, and use a
dedicated counter variable that is incremented upon processing each
path.

After this change the 'invalid file in delayed checkout' in
't0021-conversion.sh' would succeed with the future BUG() assertion
discussed above but the 'missing file in delayed checkout' test would
still fail, because its purposefully buggy filter doesn't process any
paths, so we won't execute that inner loop at all (this will be fixed
in a subsequent commit).

Signed-off-by: SZEDER Gábor <[e-mail]>
Signed-off-by: Ævar Arnfjörð Bjarmason <[e-mail]>
---
 entry.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

Patch

diff --git a/entry.c b/entry.c
index 711ee0693c7..bc4b8fcc980 100644
--- a/entry.c
+++ b/entry.c
@@ -162,7 +162,7 @@  static int remove_available_paths(struct string_list_item *item, void *cb_data)
 int finish_delayed_checkout(struct checkout *state, int *nr_checkouts)
 {
 	int errs = 0;
-	unsigned delayed_object_count;
+	unsigned processed_paths = 0;
 	off_t filtered_bytes = 0;
 	struct string_list_item *filter, *path;
 	struct progress *progress;
@@ -172,12 +172,10 @@  int finish_delayed_checkout(struct checkout *state, int *nr_checkouts)
 		return errs;
 
 	dco->state = CE_RETRY;
-	delayed_object_count = dco->paths.nr;
-	progress = start_delayed_progress(_("Filtering content"), delayed_object_count);
+	progress = start_delayed_progress(_("Filtering content"), dco->paths.nr);
 	while (dco->filters.nr > 0) {
 		for_each_string_list_item(filter, &dco->filters) {
 			struct string_list available_paths = STRING_LIST_INIT_NODUP;
-			display_progress(progress, delayed_object_count - dco->paths.nr);
 
 			if (!async_query_available_blobs(filter->string, &available_paths)) {
 				/* Filter reported an error */
@@ -224,6 +222,7 @@  int finish_delayed_checkout(struct checkout *state, int *nr_checkouts)
 				ce = index_file_exists(state->istate, path->string,
 						       strlen(path->string), 0);
 				if (ce) {
+					display_progress(progress, ++processed_paths);
 					errs |= checkout_entry(ce, state, NULL, nr_checkouts);
 					filtered_bytes += ce->ce_stat_data.sd_size;
 					display_throughput(progress, filtered_bytes);