Merge branch 'ab/squelch-empty-fsync-traces'

Omit fsync-related trace2 entries when their values are all zero.

* ab/squelch-empty-fsync-traces:
  trace2: only include "fsync" events if we git_fsync()

Author: gitster

t/t0212/parse_events.perl

@@ -216,12 +216,19 @@
 
     elsif ($event eq 'data') {
 	my $cat = $line->{'category'};
-	if ($cat eq 'test_category') {
-	    
-	    my $key = $line->{'key'};
-	    my $value = $line->{'value'};
-	    $processes->{$sid}->{'data'}->{$cat}->{$key} = $value;
-	}
+	my $key = $line->{'key'};
+	my $value = $line->{'value'};
+	$processes->{$sid}->{'data'}->{$cat}->{$key} = $value;
+    }
+
+    elsif ($event eq 'data_json') {
+	# NEEDSWORK: Ignore due to
+	# compat/win32/trace2_win32_process_info.c, which should log a
+	# "cmd_ancestry" event instead.
+    }
+
+    else {
+	push @{$processes->{$sid}->{$event}} => $line->{value};
     }
 
     # This trace2 target does not emit 'printf' events.

t/t5351-unpack-large-objects.sh

@@ -48,13 +48,33 @@ test_expect_success 'unpack big object in stream' '
 	test_dir_is_empty dest.git/objects/pack
 '
 
+check_fsync_events () {
+	local trace="$1" &&
+	shift &&
+
+	cat >expect &&
+	sed -n \
+		-e '/^{"event":"data",.*"category":"fsync",/ {
+			s/.*"category":"fsync",//;
+			s/}$//;
+			p;
+		}' \
+		<"$trace" >actual &&
+	test_cmp expect actual
+}
+
 BATCH_CONFIGURATION='-c core.fsync=loose-object -c core.fsyncmethod=batch'
 
 test_expect_success 'unpack big object in stream (core.fsyncmethod=batch)' '
 	prepare_dest 1m &&
 	GIT_TRACE2_EVENT="$(pwd)/trace2.txt" \
+	GIT_TEST_FSYNC=true \
 		git -C dest.git $BATCH_CONFIGURATION unpack-objects <pack-$PACK.pack &&
-	grep fsync/hardware-flush trace2.txt &&
+	check_fsync_events trace2.txt <<-\EOF &&
+	"key":"fsync/writeout-only","value":"6"
+	"key":"fsync/hardware-flush","value":"1"
+	EOF
+
 	test_dir_is_empty dest.git/objects/pack &&
 	git -C dest.git cat-file --batch-check="%(objectname)" <obj-list >current &&
 	cmp obj-list current

wrapper.c

@@ -616,10 +616,16 @@ int git_fsync(int fd, enum fsync_action action)
 	}
 }
 
+static void log_trace_fsync_if(const char *key, intmax_t value)
+{
+	if (value)
+		trace2_data_intmax("fsync", the_repository, key, value);
+}
+
 void trace_git_fsync_stats(void)
 {
-	trace2_data_intmax("fsync", the_repository, "fsync/writeout-only", count_fsync_writeout_only);
-	trace2_data_intmax("fsync", the_repository, "fsync/hardware-flush", count_fsync_hardware_flush);
+	log_trace_fsync_if("fsync/writeout-only", count_fsync_writeout_only);
+	log_trace_fsync_if("fsync/hardware-flush", count_fsync_hardware_flush);
 }
 
 static int warn_if_unremovable(const char *op, const char *file, int rc)