1 files changed, 41 insertions, 0 deletions

diff --git a/revision.c b/revision.c
index d3fcb7c6ff..2b06ee739c 100644
--- a/revision.c
+++ b/revision.c
@@ -30,6 +30,7 @@
 #include "hashmap.h"
 #include "utf8.h"
 #include "bloom.h"
+#include "json-writer.h"
 
 volatile show_early_output_fn_t show_early_output;
 
@@ -625,6 +626,30 @@ static void file_change(struct diff_options *options,
 	options->flags.has_changes = 1;
 }
 
+static int bloom_filter_atexit_registered;
+static unsigned int count_bloom_filter_maybe;
+static unsigned int count_bloom_filter_definitely_not;
+static unsigned int count_bloom_filter_false_positive;
+static unsigned int count_bloom_filter_not_present;
+static unsigned int count_bloom_filter_length_zero;
+
+static void trace2_bloom_filter_statistics_atexit(void)
+{
+	struct json_writer jw = JSON_WRITER_INIT;
+
+	jw_object_begin(&jw, 0);
+	jw_object_intmax(&jw, "filter_not_present", count_bloom_filter_not_present);
+	jw_object_intmax(&jw, "zero_length_filter", count_bloom_filter_length_zero);
+	jw_object_intmax(&jw, "maybe", count_bloom_filter_maybe);
+	jw_object_intmax(&jw, "definitely_not", count_bloom_filter_definitely_not);
+	jw_object_intmax(&jw, "false_positive", count_bloom_filter_false_positive);
+	jw_end(&jw);
+
+	trace2_data_json("bloom", the_repository, "statistics", &jw);
+
+	jw_release(&jw);
+}
+
 static void prepare_to_use_bloom_filter(struct rev_info *revs)
 {
 	struct pathspec_item *pi;
@@ -661,6 +686,11 @@ static void prepare_to_use_bloom_filter(struct rev_info *revs)
 	revs->bloom_key = xmalloc(sizeof(struct bloom_key));
 	fill_bloom_key(path, len, revs->bloom_key, revs->bloom_filter_settings);
 
+	if (trace2_is_enabled() && !bloom_filter_atexit_registered) {
+		atexit(trace2_bloom_filter_statistics_atexit);
+		bloom_filter_atexit_registered = 1;
+	}
+
 	free(path_alloc);
 }
 
@@ -679,10 +709,12 @@ static int check_maybe_different_in_bloom_filter(struct rev_info *revs,
 	filter = get_bloom_filter(revs->repo, commit, 0);
 
 	if (!filter) {
+		count_bloom_filter_not_present++;
 		return -1;
 	}
 
 	if (!filter->len) {
+		count_bloom_filter_length_zero++;
 		return -1;
 	}
 
@@ -690,6 +722,11 @@ static int check_maybe_different_in_bloom_filter(struct rev_info *revs,
 				       revs->bloom_key,
 				       revs->bloom_filter_settings);
 
+	if (result)
+		count_bloom_filter_maybe++;
+	else
+		count_bloom_filter_definitely_not++;
+
 	return result;
 }
 
@@ -736,6 +773,10 @@ static int rev_compare_tree(struct rev_info *revs,
 			   &revs->pruning) < 0)
 		return REV_TREE_DIFFERENT;
 
+	if (!nth_parent)
+		if (bloom_ret == 1 && tree_difference == REV_TREE_SAME)
+			count_bloom_filter_false_positive++;
+
 	return tree_difference;
 }