From d50a23bf4ba224da91cd6bd3c8bc7a1e42225616 Mon Sep 17 00:00:00 2001
From: Tyler Yahn <MrAlias@users.noreply.github.com>
Date: Mon, 26 Feb 2024 23:22:58 -0800
Subject: [PATCH] Clear aggregate value maps instead of deleting entries
 (#4981)

---
 .../internal/aggregate/exponential_histogram.go     |  4 +++-
 sdk/metric/internal/aggregate/histogram.go          |  4 ++--
 sdk/metric/internal/aggregate/lastvalue.go          |  4 ++--
 sdk/metric/internal/aggregate/sum.go                | 13 ++++++-------
 4 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/sdk/metric/internal/aggregate/exponential_histogram.go b/sdk/metric/internal/aggregate/exponential_histogram.go
index 4139a6d1560..7b66801c315 100644
--- a/sdk/metric/internal/aggregate/exponential_histogram.go
+++ b/sdk/metric/internal/aggregate/exponential_histogram.go
@@ -387,9 +387,11 @@ func (e *expoHistogram[N]) delta(dest *metricdata.Aggregation) int {
 
 		b.res.Collect(&hDPts[i].Exemplars)
 
-		delete(e.values, a)
 		i++
 	}
+	// Unused attribute sets do not report.
+	clear(e.values)
+
 	e.start = t
 	h.DataPoints = hDPts
 	*dest = h
diff --git a/sdk/metric/internal/aggregate/histogram.go b/sdk/metric/internal/aggregate/histogram.go
index d695ad64c9e..abc12e55153 100644
--- a/sdk/metric/internal/aggregate/histogram.go
+++ b/sdk/metric/internal/aggregate/histogram.go
@@ -175,10 +175,10 @@ func (s *histogram[N]) delta(dest *metricdata.Aggregation) int {
 
 		b.res.Collect(&hDPts[i].Exemplars)
 
-		// Unused attribute sets do not report.
-		delete(s.values, a)
 		i++
 	}
+	// Unused attribute sets do not report.
+	clear(s.values)
 	// The delta collection cycle resets.
 	s.start = t
 
diff --git a/sdk/metric/internal/aggregate/lastvalue.go b/sdk/metric/internal/aggregate/lastvalue.go
index 5699e728f1f..987887042f0 100644
--- a/sdk/metric/internal/aggregate/lastvalue.go
+++ b/sdk/metric/internal/aggregate/lastvalue.go
@@ -82,8 +82,8 @@ func (s *lastValue[N]) computeAggregation(dest *[]metricdata.DataPoint[N]) {
 		(*dest)[i].Time = v.timestamp
 		(*dest)[i].Value = v.value
 		v.res.Collect(&(*dest)[i].Exemplars)
-		// Do not report stale values.
-		delete(s.values, a)
 		i++
 	}
+	// Do not report stale values.
+	clear(s.values)
 }
diff --git a/sdk/metric/internal/aggregate/sum.go b/sdk/metric/internal/aggregate/sum.go
index 02de2483f3b..29e4fd3968f 100644
--- a/sdk/metric/internal/aggregate/sum.go
+++ b/sdk/metric/internal/aggregate/sum.go
@@ -104,10 +104,10 @@ func (s *sum[N]) delta(dest *metricdata.Aggregation) int {
 		dPts[i].Time = t
 		dPts[i].Value = val.n
 		val.res.Collect(&dPts[i].Exemplars)
-		// Do not report stale values.
-		delete(s.values, attr)
 		i++
 	}
+	// Do not report stale values.
+	clear(s.values)
 	// The delta collection cycle resets.
 	s.start = t
 
@@ -200,11 +200,10 @@ func (s *precomputedSum[N]) delta(dest *metricdata.Aggregation) int {
 		value.res.Collect(&dPts[i].Exemplars)
 
 		newReported[attr] = value.n
-		// Unused attribute sets do not report.
-		delete(s.values, attr)
 		i++
 	}
-	// Unused attribute sets are forgotten.
+	// Unused attribute sets do not report.
+	clear(s.values)
 	s.reported = newReported
 	// The delta collection cycle resets.
 	s.start = t
@@ -238,10 +237,10 @@ func (s *precomputedSum[N]) cumulative(dest *metricdata.Aggregation) int {
 		dPts[i].Value = val.n
 		val.res.Collect(&dPts[i].Exemplars)
 
-		// Unused attribute sets do not report.
-		delete(s.values, attr)
 		i++
 	}
+	// Unused attribute sets do not report.
+	clear(s.values)
 
 	sData.DataPoints = dPts
 	*dest = sData