diff mbox series

[v4,10/16] refs/packed-backend.c: add trace2 counters for jump list

Message ID 49c8f5173aab19112afcd762337012a5c2f0f381.1687270849.git.me@ttaylorr.com (mailing list archive)
State Superseded
Headers show
Series refs: implement jump lists for packed backend | expand

Commit Message

Taylor Blau June 20, 2023, 2:21 p.m. UTC
The previous commit added low-level tests to ensure that the packed-refs
iterator did not enumerate excluded sections of the refspace.

However, there was no guarantee that these sections weren't being
visited, only that they were being suppressed from the output. To harden
these tests, add a trace2 counter which tracks the number of regions
skipped by the packed-refs iterator, and assert on its value.

Suggested-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 refs/packed-backend.c   |  2 ++
 t/t1419-exclude-refs.sh | 59 ++++++++++++++++++++++++++++-------------
 trace2.h                |  2 ++
 trace2/tr2_ctr.c        |  5 ++++
 4 files changed, 49 insertions(+), 19 deletions(-)
diff mbox series

Patch

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index f624c9921a..80b877e00c 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -12,6 +12,7 @@ 
 #include "../chdir-notify.h"
 #include "../wrapper.h"
 #include "../write-or-die.h"
+#include "../trace2.h"
 
 enum mmap_strategy {
 	/*
@@ -845,6 +846,7 @@  static int next_record(struct packed_ref_iterator *iter)
 		iter->jump_cur++;
 		if (iter->pos < curr->end) {
 			iter->pos = curr->end;
+			trace2_counter_add(TRACE2_COUNTER_ID_PACKED_REFS_JUMPS, 1);
 			break;
 		}
 	}
diff --git a/t/t1419-exclude-refs.sh b/t/t1419-exclude-refs.sh
index bc534c8ea1..5d8c86b657 100755
--- a/t/t1419-exclude-refs.sh
+++ b/t/t1419-exclude-refs.sh
@@ -9,7 +9,8 @@  TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 for_each_ref__exclude () {
-	test-tool ref-store main for-each-ref--exclude "$@" >actual.raw
+	GIT_TRACE2_PERF=1 test-tool ref-store main \
+		for-each-ref--exclude "$@" >actual.raw
 	cut -d ' ' -f 2 actual.raw
 }
 
@@ -17,6 +18,17 @@  for_each_ref () {
 	git for-each-ref --format='%(refname)' "$@"
 }
 
+assert_jumps () {
+	local nr="$1"
+	local trace="$2"
+
+	grep -q "name:jumps_made value:$nr$" $trace
+}
+
+assert_no_jumps () {
+	! assert_jumps ".*" "$1"
+}
+
 test_expect_success 'setup' '
 	test_commit --no-tag base &&
 	base="$(git rev-parse HEAD)" &&
@@ -35,67 +47,76 @@  test_expect_success 'setup' '
 '
 
 test_expect_success 'excluded region in middle' '
-	for_each_ref__exclude refs/heads refs/heads/foo >actual &&
+	for_each_ref__exclude refs/heads refs/heads/foo >actual 2>perf &&
 	for_each_ref refs/heads/bar refs/heads/baz refs/heads/quux >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_jumps 1 perf
 '
 
 test_expect_success 'excluded region at beginning' '
-	for_each_ref__exclude refs/heads refs/heads/bar >actual &&
+	for_each_ref__exclude refs/heads refs/heads/bar >actual 2>perf &&
 	for_each_ref refs/heads/baz refs/heads/foo refs/heads/quux >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_jumps 1 perf
 '
 
 test_expect_success 'excluded region at end' '
-	for_each_ref__exclude refs/heads refs/heads/quux >actual &&
+	for_each_ref__exclude refs/heads refs/heads/quux >actual 2>perf &&
 	for_each_ref refs/heads/foo refs/heads/bar refs/heads/baz >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_jumps 1 perf
 '
 
 test_expect_success 'disjoint excluded regions' '
-	for_each_ref__exclude refs/heads refs/heads/bar refs/heads/quux >actual &&
+	for_each_ref__exclude refs/heads refs/heads/bar refs/heads/quux >actual 2>perf &&
 	for_each_ref refs/heads/baz refs/heads/foo >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_jumps 2 perf
 '
 
 test_expect_success 'adjacent, non-overlapping excluded regions' '
-	for_each_ref__exclude refs/heads refs/heads/bar refs/heads/baz >actual &&
+	for_each_ref__exclude refs/heads refs/heads/bar refs/heads/baz >actual 2>perf &&
 	for_each_ref refs/heads/foo refs/heads/quux >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_jumps 1 perf
 '
 
 test_expect_success 'overlapping excluded regions' '
-	for_each_ref__exclude refs/heads refs/heads/ba refs/heads/baz >actual &&
+	for_each_ref__exclude refs/heads refs/heads/ba refs/heads/baz >actual 2>perf &&
 	for_each_ref refs/heads/foo refs/heads/quux >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_jumps 1 perf
 '
 
 test_expect_success 'several overlapping excluded regions' '
 	for_each_ref__exclude refs/heads \
-		refs/heads/bar refs/heads/baz refs/heads/foo >actual &&
+		refs/heads/bar refs/heads/baz refs/heads/foo >actual 2>perf &&
 	for_each_ref refs/heads/quux >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_jumps 1 perf
 '
 
 test_expect_success 'non-matching excluded section' '
-	for_each_ref__exclude refs/heads refs/heads/does/not/exist >actual &&
+	for_each_ref__exclude refs/heads refs/heads/does/not/exist >actual 2>perf &&
 	for_each_ref >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_no_jumps perf
 '
 
 test_expect_success 'meta-characters are discarded' '
-	for_each_ref__exclude refs/heads "refs/heads/ba*" >actual &&
+	for_each_ref__exclude refs/heads "refs/heads/ba*" >actual 2>perf &&
 	for_each_ref >expect &&
 
-	test_cmp expect actual
+	test_cmp expect actual &&
+	assert_no_jumps perf
 '
 
 test_done
diff --git a/trace2.h b/trace2.h
index 4ced30c0db..9452e291f5 100644
--- a/trace2.h
+++ b/trace2.h
@@ -551,6 +551,8 @@  enum trace2_counter_id {
 	TRACE2_COUNTER_ID_TEST1 = 0, /* emits summary event only */
 	TRACE2_COUNTER_ID_TEST2,     /* emits summary and thread events */
 
+	TRACE2_COUNTER_ID_PACKED_REFS_JUMPS, /* counts number of jumps */
+
 	/* Add additional counter definitions before here. */
 	TRACE2_NUMBER_OF_COUNTERS
 };
diff --git a/trace2/tr2_ctr.c b/trace2/tr2_ctr.c
index b342d3b1a3..50570d0165 100644
--- a/trace2/tr2_ctr.c
+++ b/trace2/tr2_ctr.c
@@ -27,6 +27,11 @@  static struct tr2_counter_metadata tr2_counter_metadata[TRACE2_NUMBER_OF_COUNTER
 		.name = "test2",
 		.want_per_thread_events = 1,
 	},
+	[TRACE2_COUNTER_ID_PACKED_REFS_JUMPS] = {
+		.category = "packed-refs",
+		.name = "jumps_made",
+		.want_per_thread_events = 0,
+	},
 
 	/* Add additional metadata before here. */
 };