Flush reporter from root scope only (#108)

scope.go

@@ -202,11 +202,9 @@ func (s *scope) report(r StatsReporter) {
 		histogram.report(s.fullyQualifiedName(name), s.tags, r)
 	}
 	s.hm.RUnlock()
-
-	r.Flush()
 }
 
-func (s *scope) cachedReport(c CachedStatsReporter) {
+func (s *scope) cachedReport() {
 	s.cm.RLock()
 	for _, counter := range s.counters {
 		counter.cachedReport()
@@ -226,8 +224,6 @@ func (s *scope) cachedReport(c CachedStatsReporter) {
 		histogram.cachedReport()
 	}
 	s.hm.RUnlock()
-
-	c.Flush()
 }
 
 // reportLoop is used by the root scope for periodic reporting
@@ -266,10 +262,12 @@ func (s *scope) reportRegistryWithLock() {
 		for _, ss := range s.registry.subscopes {
 			ss.report(s.reporter)
 		}
+		s.reporter.Flush()
 	} else if s.cachedReporter != nil {
 		for _, ss := range s.registry.subscopes {
-			ss.cachedReport(s.cachedReporter)
+			ss.cachedReport()
 		}
+		s.cachedReporter.Flush()
 	}
 	s.registry.RUnlock()
 }

scope_test.go

@@ -327,8 +327,44 @@ func TestCachedReportLoop(t *testing.T) {
 	r.hg.Add(1)
 	s.Histogram("baz", MustMakeLinearValueBuckets(0, 10, 10)).
 		RecordValue(42.42)
+	r.WaitAll()
+}
 
+func testReportLoopFlushOnce(t *testing.T, r *testStatsReporter, s Scope) {
+	r.cg.Add(2)
+	s.Counter("foobar").Inc(1)
+	s.SubScope("baz").Counter("bar").Inc(1)
+	r.gg.Add(2)
+	s.Gauge("zed").Update(1)
+	s.SubScope("baz").Gauge("zed").Update(1)
+	r.tg.Add(2)
+	s.Timer("ticky").Record(time.Millisecond * 175)
+	s.SubScope("woof").Timer("sod").Record(time.Millisecond * 175)
+	r.hg.Add(2)
+	s.SubScope("woofers").Histogram("boo", MustMakeLinearValueBuckets(0, 10, 10)).
+		RecordValue(42.42)
+	s.Histogram("baz", MustMakeLinearValueBuckets(0, 10, 10)).
+		RecordValue(42.42)
 	r.WaitAll()
+
+	v := atomic.LoadInt32(&r.flushes)
+	assert.Equal(t, int32(1), v)
+}
+
+func TestCachedReporterFlushOnce(t *testing.T) {
+	r := newTestStatsReporter()
+	s, closer := NewRootScope(ScopeOptions{CachedReporter: r}, 10*time.Millisecond)
+	defer closer.Close()
+
+	testReportLoopFlushOnce(t, r, s)
+}
+
+func TestReporterFlushOnce(t *testing.T) {
+	r := newTestStatsReporter()
+	s, closer := NewRootScope(ScopeOptions{Reporter: r}, 10*time.Millisecond)
+	defer closer.Close()
+
+	testReportLoopFlushOnce(t, r, s)
 }
 
 func TestWriteOnce(t *testing.T) {
@@ -431,7 +467,7 @@ func TestCachedReporter(t *testing.T) {
 	s.Histogram("qux", MustMakeLinearDurationBuckets(0, 10*time.Millisecond, 10)).
 		RecordDuration(42 * time.Millisecond)
 
-	s.cachedReport(r)
+	s.cachedReport()
 	r.WaitAll()
 
 	assert.EqualValues(t, 1, r.counters["bar"].val)