Rename SynchronizedCopy to SynchronizedMove and update comment (#858)

exporters/metric/stdout/stdout_test.go

@@ -104,7 +104,7 @@ func TestStdoutTimestamp(t *testing.T) {
 	lvagg, ckpt := test.Unslice2(lastvalue.New(2))
 
 	aggtest.CheckedUpdate(t, lvagg, metric.NewInt64Number(321), &desc)
-	require.NoError(t, lvagg.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, lvagg.SynchronizedMove(ckpt, &desc))
 
 	checkpointSet.Add(&desc, ckpt)
 
@@ -151,7 +151,7 @@ func TestStdoutCounterFormat(t *testing.T) {
 	cagg, ckpt := test.Unslice2(sum.New(2))
 
 	aggtest.CheckedUpdate(fix.t, cagg, metric.NewInt64Number(123), &desc)
-	require.NoError(t, cagg.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, cagg.SynchronizedMove(ckpt, &desc))
 
 	checkpointSet.Add(&desc, ckpt, kv.String("A", "B"), kv.String("C", "D"))
 
@@ -169,7 +169,7 @@ func TestStdoutLastValueFormat(t *testing.T) {
 	lvagg, ckpt := test.Unslice2(lastvalue.New(2))
 
 	aggtest.CheckedUpdate(fix.t, lvagg, metric.NewFloat64Number(123.456), &desc)
-	require.NoError(t, lvagg.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, lvagg.SynchronizedMove(ckpt, &desc))
 
 	checkpointSet.Add(&desc, ckpt, kv.String("A", "B"), kv.String("C", "D"))
 
@@ -189,7 +189,7 @@ func TestStdoutMinMaxSumCount(t *testing.T) {
 
 	aggtest.CheckedUpdate(fix.t, magg, metric.NewFloat64Number(123.456), &desc)
 	aggtest.CheckedUpdate(fix.t, magg, metric.NewFloat64Number(876.543), &desc)
-	require.NoError(t, magg.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, magg.SynchronizedMove(ckpt, &desc))
 
 	checkpointSet.Add(&desc, ckpt, kv.String("A", "B"), kv.String("C", "D"))
 
@@ -212,7 +212,7 @@ func TestStdoutValueRecorderFormat(t *testing.T) {
 		aggtest.CheckedUpdate(fix.t, aagg, metric.NewFloat64Number(float64(i)+0.5), &desc)
 	}
 
-	require.NoError(t, aagg.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, aagg.SynchronizedMove(ckpt, &desc))
 
 	checkpointSet.Add(&desc, ckpt, kv.String("A", "B"), kv.String("C", "D"))
 
@@ -256,7 +256,7 @@ func TestStdoutNoData(t *testing.T) {
 
 			checkpointSet := test.NewCheckpointSet(testResource)
 
-			require.NoError(t, agg.SynchronizedCopy(ckpt, &desc))
+			require.NoError(t, agg.SynchronizedMove(ckpt, &desc))
 
 			checkpointSet.Add(&desc, ckpt)
 
@@ -278,7 +278,7 @@ func TestStdoutLastValueNotSet(t *testing.T) {
 	desc := metric.NewDescriptor("test.name", metric.ValueObserverKind, metric.Float64NumberKind)
 
 	lvagg, ckpt := test.Unslice2(lastvalue.New(2))
-	require.NoError(t, lvagg.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, lvagg.SynchronizedMove(ckpt, &desc))
 
 	checkpointSet.Add(&desc, lvagg, kv.String("A", "B"), kv.String("C", "D"))
 
@@ -330,7 +330,7 @@ func TestStdoutResource(t *testing.T) {
 		lvagg, ckpt := test.Unslice2(lastvalue.New(2))
 
 		aggtest.CheckedUpdate(fix.t, lvagg, metric.NewFloat64Number(123.456), &desc)
-		require.NoError(t, lvagg.SynchronizedCopy(ckpt, &desc))
+		require.NoError(t, lvagg.SynchronizedMove(ckpt, &desc))
 
 		checkpointSet.Add(&desc, ckpt, tc.attrs...)
 

exporters/metric/test/test.go

@@ -52,8 +52,8 @@ func (NoopAggregator) Update(context.Context, metric.Number, *metric.Descriptor)
 	return nil
 }
 
-// SynchronizedCopy implements export.Aggregator.
-func (NoopAggregator) SynchronizedCopy(export.Aggregator, *metric.Descriptor) error {
+// SynchronizedMove implements export.Aggregator.
+func (NoopAggregator) SynchronizedMove(export.Aggregator, *metric.Descriptor) error {
 	return nil
 }
 

exporters/otlp/internal/transform/metric_test.go

@@ -101,7 +101,7 @@ func TestMinMaxSumCountValue(t *testing.T) {
 	assert.EqualError(t, err, aggregation.ErrNoData.Error())
 
 	// Checkpoint to set non-zero values
-	require.NoError(t, mmsc.SynchronizedCopy(ckpt, &metric.Descriptor{}))
+	require.NoError(t, mmsc.SynchronizedMove(ckpt, &metric.Descriptor{}))
 	min, max, sum, count, err := minMaxSumCountValues(ckpt.(aggregation.MinMaxSumCount))
 	if assert.NoError(t, err) {
 		assert.Equal(t, min, metric.NewInt64Number(1))
@@ -158,7 +158,7 @@ func TestMinMaxSumCountMetricDescriptor(t *testing.T) {
 	if !assert.NoError(t, mmsc.Update(ctx, 1, &metric.Descriptor{})) {
 		return
 	}
-	require.NoError(t, mmsc.SynchronizedCopy(ckpt, &metric.Descriptor{}))
+	require.NoError(t, mmsc.SynchronizedMove(ckpt, &metric.Descriptor{}))
 	for _, test := range tests {
 		desc := metric.NewDescriptor(test.name, test.metricKind, test.numberKind,
 			metric.WithDescription(test.description),
@@ -179,7 +179,7 @@ func TestMinMaxSumCountDatapoints(t *testing.T) {
 
 	assert.NoError(t, mmsc.Update(context.Background(), 1, &desc))
 	assert.NoError(t, mmsc.Update(context.Background(), 10, &desc))
-	require.NoError(t, mmsc.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, mmsc.SynchronizedMove(ckpt, &desc))
 	expected := []*metricpb.SummaryDataPoint{
 		{
 			Count: 2,
@@ -280,7 +280,7 @@ func TestSumInt64DataPoints(t *testing.T) {
 	labels := label.NewSet()
 	s, ckpt := test.Unslice2(sumAgg.New(2))
 	assert.NoError(t, s.Update(context.Background(), metric.Number(1), &desc))
-	require.NoError(t, s.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, s.SynchronizedMove(ckpt, &desc))
 	record := export.NewRecord(&desc, &labels, nil, ckpt.Aggregation(), intervalStart, intervalEnd)
 	if m, err := sum(record, ckpt.(aggregation.Sum)); assert.NoError(t, err) {
 		assert.Equal(t, []*metricpb.Int64DataPoint{{
@@ -299,7 +299,7 @@ func TestSumFloat64DataPoints(t *testing.T) {
 	labels := label.NewSet()
 	s, ckpt := test.Unslice2(sumAgg.New(2))
 	assert.NoError(t, s.Update(context.Background(), metric.NewFloat64Number(1), &desc))
-	require.NoError(t, s.SynchronizedCopy(ckpt, &desc))
+	require.NoError(t, s.SynchronizedMove(ckpt, &desc))
 	record := export.NewRecord(&desc, &labels, nil, ckpt.Aggregation(), intervalStart, intervalEnd)
 	if m, err := sum(record, ckpt.(aggregation.Sum)); assert.NoError(t, err) {
 		assert.Equal(t, []*metricpb.Int64DataPoint(nil), m.Int64DataPoints)

exporters/otlp/otlp_metric_test.go

@@ -741,7 +741,7 @@ func runMetricExportTest(t *testing.T, exp *Exporter, rs []record, expected []me
 		default:
 			t.Fatalf("invalid number kind: %v", r.nKind)
 		}
-		require.NoError(t, agg.SynchronizedCopy(ckpt, &desc))
+		require.NoError(t, agg.SynchronizedMove(ckpt, &desc))
 
 		equiv := r.resource.Equivalent()
 		resources[equiv] = r.resource

sdk/export/metric/metric.go

@@ -127,11 +127,12 @@ type Aggregator interface {
 	// inspected for a `correlation.Map` or `trace.SpanContext`.
 	Update(context.Context, metric.Number, *metric.Descriptor) error
 
-	// SynchronizedCopy is called during collection to finish one
+	// SynchronizedMove is called during collection to finish one
 	// period of aggregation by atomically saving the
-	// currently-updating state into the argument Aggregator.
+	// currently-updating state into the argument Aggregator AND
+	// resetting the current value to the zero state.
 	//
-	// SynchronizedCopy() is called concurrently with Update().  These
+	// SynchronizedMove() is called concurrently with Update().  These
 	// two methods must be synchronized with respect to each
 	// other, for correctness.
 	//
@@ -145,11 +146,11 @@ type Aggregator interface {
 	//
 	// This call has no Context argument because it is expected to
 	// perform only computation.
-	SynchronizedCopy(destination Aggregator, descriptor *metric.Descriptor) error
+	SynchronizedMove(destination Aggregator, descriptor *metric.Descriptor) error
 
 	// Merge combines the checkpointed state from the argument
 	// Aggregator into this Aggregator.  Merge is not synchronized
-	// with respect to Update or SynchronizedCopy.
+	// with respect to Update or SynchronizedMove.
 	//
 	// The owner of an Aggregator being merged is responsible for
 	// synchronization of both Aggregator states.

sdk/metric/aggregator/array/array.go

@@ -46,7 +46,7 @@ var _ aggregation.Points = &Aggregator{}
 
 // New returns a new array aggregator, which aggregates recorded
 // measurements by storing them in an array.  This type uses a mutex
-// for Update() and SynchronizedCopy() concurrency.
+// for Update() and SynchronizedMove() concurrency.
 func New(cnt int) []Aggregator {
 	return make([]Aggregator, cnt)
 }
@@ -92,9 +92,9 @@ func (c *Aggregator) Points() ([]metric.Number, error) {
 	return c.points, nil
 }
 
-// SynchronizedCopy saves the current state to oa and resets the current state to
+// SynchronizedMove saves the current state to oa and resets the current state to
 // the empty set, taking a lock to prevent concurrent Update() calls.
-func (c *Aggregator) SynchronizedCopy(oa export.Aggregator, desc *metric.Descriptor) error {
+func (c *Aggregator) SynchronizedMove(oa export.Aggregator, desc *metric.Descriptor) error {
 	o, _ := oa.(*Aggregator)
 	if o == nil {
 		return aggregator.NewInconsistentAggregatorError(c, oa)
@@ -114,7 +114,7 @@ func (c *Aggregator) SynchronizedCopy(oa export.Aggregator, desc *metric.Descrip
 }
 
 // Update adds the recorded measurement to the current data set.
-// Update takes a lock to prevent concurrent Update() and SynchronizedCopy()
+// Update takes a lock to prevent concurrent Update() and SynchronizedMove()
 // calls.
 func (c *Aggregator) Update(_ context.Context, number metric.Number, desc *metric.Descriptor) error {
 	c.lock.Lock()

sdk/metric/aggregator/array/array_test.go

@@ -77,7 +77,7 @@ func (ut *updateTest) run(t *testing.T, profile test.Profile) {
 		test.CheckedUpdate(t, agg, y, descriptor)
 	}
 
-	err := agg.SynchronizedCopy(ckpt, descriptor)
+	err := agg.SynchronizedMove(ckpt, descriptor)
 	require.NoError(t, err)
 
 	checkZero(t, agg, descriptor)
@@ -154,8 +154,8 @@ func (mt *mergeTest) run(t *testing.T, profile test.Profile) {
 		}
 	}
 
-	require.NoError(t, agg1.SynchronizedCopy(ckpt1, descriptor))
-	require.NoError(t, agg2.SynchronizedCopy(ckpt2, descriptor))
+	require.NoError(t, agg1.SynchronizedMove(ckpt1, descriptor))
+	require.NoError(t, agg2.SynchronizedMove(ckpt2, descriptor))
 
 	checkZero(t, agg1, descriptor)
 	checkZero(t, agg2, descriptor)
@@ -232,7 +232,7 @@ func TestArrayErrors(t *testing.T) {
 		if profile.NumberKind == metric.Float64NumberKind {
 			test.CheckedUpdate(t, agg, metric.NewFloat64Number(math.NaN()), descriptor)
 		}
-		require.NoError(t, agg.SynchronizedCopy(ckpt, descriptor))
+		require.NoError(t, agg.SynchronizedMove(ckpt, descriptor))
 
 		count, err := ckpt.Count()
 		require.Equal(t, int64(1), count, "NaN value was not counted")
@@ -297,7 +297,7 @@ func TestArrayFloat64(t *testing.T) {
 		test.CheckedUpdate(t, agg, metric.NewFloat64Number(f), descriptor)
 	}
 
-	require.NoError(t, agg.SynchronizedCopy(ckpt, descriptor))
+	require.NoError(t, agg.SynchronizedMove(ckpt, descriptor))
 
 	all.Sort()
 

sdk/metric/aggregator/ddsketch/ddsketch.go

@@ -112,9 +112,9 @@ func (c *Aggregator) toNumber(f float64) metric.Number {
 	return metric.NewInt64Number(int64(f))
 }
 
-// SynchronizedCopy saves the current state into oa and resets the current state to
+// SynchronizedMove saves the current state into oa and resets the current state to
 // a new sketch, taking a lock to prevent concurrent Update() calls.
-func (c *Aggregator) SynchronizedCopy(oa export.Aggregator, _ *metric.Descriptor) error {
+func (c *Aggregator) SynchronizedMove(oa export.Aggregator, _ *metric.Descriptor) error {
 	o, _ := oa.(*Aggregator)
 	if o == nil {
 		return aggregator.NewInconsistentAggregatorError(c, oa)
@@ -129,7 +129,7 @@ func (c *Aggregator) SynchronizedCopy(oa export.Aggregator, _ *metric.Descriptor
 }
 
 // Update adds the recorded measurement to the current data set.
-// Update takes a lock to prevent concurrent Update() and SynchronizedCopy()
+// Update takes a lock to prevent concurrent Update() and SynchronizedMove()
 // calls.
 func (c *Aggregator) Update(_ context.Context, number metric.Number, desc *metric.Descriptor) error {
 	c.lock.Lock()

sdk/metric/aggregator/ddsketch/ddsketch_test.go

@@ -80,7 +80,7 @@ func (ut *updateTest) run(t *testing.T, profile test.Profile) {
 		test.CheckedUpdate(t, agg, y, descriptor)
 	}
 
-	err := agg.SynchronizedCopy(ckpt, descriptor)
+	err := agg.SynchronizedMove(ckpt, descriptor)
 	require.NoError(t, err)
 
 	checkZero(t, agg, descriptor)
@@ -156,8 +156,8 @@ func (mt *mergeTest) run(t *testing.T, profile test.Profile) {
 		}
 	}
 
-	require.NoError(t, agg1.SynchronizedCopy(ckpt1, descriptor))
-	require.NoError(t, agg2.SynchronizedCopy(ckpt2, descriptor))
+	require.NoError(t, agg1.SynchronizedMove(ckpt1, descriptor))
+	require.NoError(t, agg2.SynchronizedMove(ckpt2, descriptor))
 
 	checkZero(t, agg1, descriptor)
 	checkZero(t, agg1, descriptor)

sdk/metric/aggregator/histogram/histogram.go

@@ -111,11 +111,11 @@ func (c *Aggregator) Histogram() (aggregation.Buckets, error) {
 	}, nil
 }
 
-// SynchronizedCopy saves the current state into oa and resets the current state to
+// SynchronizedMove saves the current state into oa and resets the current state to
 // the empty set.  Since no locks are taken, there is a chance that
 // the independent Sum, Count and Bucket Count are not consistent with each
 // other.
-func (c *Aggregator) SynchronizedCopy(oa export.Aggregator, desc *metric.Descriptor) error {
+func (c *Aggregator) SynchronizedMove(oa export.Aggregator, desc *metric.Descriptor) error {
 	o, _ := oa.(*Aggregator)
 	if o == nil {
 		return aggregator.NewInconsistentAggregatorError(c, oa)

sdk/metric/aggregator/histogram/histogram_test.go

@@ -121,7 +121,7 @@ func testHistogram(t *testing.T, profile test.Profile, policy policy) {
 		test.CheckedUpdate(t, agg, x, descriptor)
 	}
 
-	require.NoError(t, agg.SynchronizedCopy(ckpt, descriptor))
+	require.NoError(t, agg.SynchronizedMove(ckpt, descriptor))
 
 	checkZero(t, agg, descriptor)
 
@@ -184,8 +184,8 @@ func TestHistogramMerge(t *testing.T) {
 			test.CheckedUpdate(t, agg2, x, descriptor)
 		}
 
-		require.NoError(t, agg1.SynchronizedCopy(ckpt1, descriptor))
-		require.NoError(t, agg2.SynchronizedCopy(ckpt2, descriptor))
+		require.NoError(t, agg1.SynchronizedMove(ckpt1, descriptor))
+		require.NoError(t, agg2.SynchronizedMove(ckpt2, descriptor))
 
 		test.CheckedMerge(t, ckpt1, ckpt2, descriptor)
 
@@ -223,7 +223,7 @@ func TestHistogramNotSet(t *testing.T) {
 
 		agg, ckpt := new2(descriptor)
 
-		err := agg.SynchronizedCopy(ckpt, descriptor)
+		err := agg.SynchronizedMove(ckpt, descriptor)
 		require.NoError(t, err)
 
 		checkZero(t, agg, descriptor)

sdk/metric/aggregator/lastvalue/lastvalue.go

@@ -90,8 +90,8 @@ func (g *Aggregator) LastValue() (metric.Number, time.Time, error) {
 	return gd.value.AsNumber(), gd.timestamp, nil
 }
 
-// SynchronizedCopy atomically saves the current value.
-func (g *Aggregator) SynchronizedCopy(oa export.Aggregator, _ *metric.Descriptor) error {
+// SynchronizedMove atomically saves the current value.
+func (g *Aggregator) SynchronizedMove(oa export.Aggregator, _ *metric.Descriptor) error {
 	o, _ := oa.(*Aggregator)
 	if o == nil {
 		return aggregator.NewInconsistentAggregatorError(g, oa)

sdk/metric/aggregator/lastvalue/lastvalue_test.go

@@ -80,7 +80,7 @@ func TestLastValueUpdate(t *testing.T) {
 			test.CheckedUpdate(t, agg, x, record)
 		}
 
-		err := agg.SynchronizedCopy(ckpt, record)
+		err := agg.SynchronizedMove(ckpt, record)
 		require.NoError(t, err)
 
 		lv, _, err := ckpt.LastValue()
@@ -102,8 +102,8 @@ func TestLastValueMerge(t *testing.T) {
 		test.CheckedUpdate(t, agg1, first1, descriptor)
 		test.CheckedUpdate(t, agg2, first2, descriptor)
 
-		require.NoError(t, agg1.SynchronizedCopy(ckpt1, descriptor))
-		require.NoError(t, agg2.SynchronizedCopy(ckpt2, descriptor))
+		require.NoError(t, agg1.SynchronizedMove(ckpt1, descriptor))
+		require.NoError(t, agg2.SynchronizedMove(ckpt2, descriptor))
 
 		checkZero(t, agg1)
 		checkZero(t, agg2)
@@ -127,7 +127,7 @@ func TestLastValueNotSet(t *testing.T) {
 	descriptor := test.NewAggregatorTest(metric.ValueObserverKind, metric.Int64NumberKind)
 
 	g, ckpt := new2()
-	require.NoError(t, g.SynchronizedCopy(ckpt, descriptor))
+	require.NoError(t, g.SynchronizedMove(ckpt, descriptor))
 
 	checkZero(t, g)
 }

sdk/metric/aggregator/minmaxsumcount/mmsc.go

@@ -48,7 +48,7 @@ var _ aggregation.MinMaxSumCount = &Aggregator{}
 // count.  It does not compute quantile information other than Min and
 // Max.
 //
-// This type uses a mutex for Update() and SynchronizedCopy() concurrency.
+// This type uses a mutex for Update() and SynchronizedMove() concurrency.
 func New(cnt int, desc *metric.Descriptor) []Aggregator {
 	kind := desc.NumberKind()
 	aggs := make([]Aggregator, cnt)
@@ -101,9 +101,9 @@ func (c *Aggregator) Max() (metric.Number, error) {
 	return c.max, nil
 }
 
-// SynchronizedCopy saves the current state into oa and resets the current state to
+// SynchronizedMove saves the current state into oa and resets the current state to
 // the empty set.
-func (c *Aggregator) SynchronizedCopy(oa export.Aggregator, desc *metric.Descriptor) error {
+func (c *Aggregator) SynchronizedMove(oa export.Aggregator, desc *metric.Descriptor) error {
 	o, _ := oa.(*Aggregator)
 	if o == nil {
 		return aggregator.NewInconsistentAggregatorError(c, oa)