split-index: count the number of deleted entries

'struct split_index' contains the field 'nr_deletions', whose name
with the 'nr_' prefix suggests that it contains the number of deleted
cache entries.  However, barring its initialization to 0, this field
is only ever set to 1, indicating that there is at least one deleted
entry, but not the number of deleted entries.  Luckily, this doesn't
cause any issues (other than confusing the reader, that is), because
the only place reading this field uses it in the same sense, i.e.: 'if
(si->nr_deletions)'.

To avoid confusion, we could either rename this field to something
like 'has_deletions' to make its name match its role, or make it a
counter of deleted cache entries to match its name.

Let's make it a counter, to keep it in sync with the related field
'nr_replacements', which does contain the number of replaced cache
entries.  This will also give developers debugging the split index
code easy access to the number of deleted cache entries.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/split-index.c b/split-index.c
index 84f067e10d2cec1d77ec1a51f0f38cc5a29dd89f..548272ec338e8e9c5ca6aa75b6e4f0395f60aadc 100644 (file)
--- a/split-index.c
+++ b/split-index.c
@@ -111,7 +111,7 @@ static void mark_entry_for_delete(size_t pos, void *data)
                die("position for delete %d exceeds base index size %d",
                    (int)pos, istate->cache_nr);
        istate->cache[pos]->ce_flags |= CE_REMOVE;
-       istate->split_index->nr_deletions = 1;
+       istate->split_index->nr_deletions++;
 }
 
 static void replace_entry(size_t pos, void *data)