[transformprocessor]: Remove unnecessary data copy when transform sum…

… to/from gauge (#35177)

Signed-off-by: Bogdan Drutu <[email protected]>

.chloggen/rm-copy-transformprocessor.yaml

@@ -0,0 +1,22 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'enhancement'
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: transformprocessor
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Remove unnecessary data copy when transform sum to/from gauge
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [35177]
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

processor/transformprocessor/internal/metrics/func_convert_gauge_to_sum.go

@@ -54,8 +54,8 @@ func convertGaugeToSum(stringAggTemp string, monotonic bool) (ottl.ExprFunc[ottl
 		metric.SetEmptySum().SetAggregationTemporality(aggTemp)
 		metric.Sum().SetIsMonotonic(monotonic)
 
-		// Setting the data type removed all the data points, so we must copy them back to the metric.
-		dps.CopyTo(metric.Sum().DataPoints())
+		// Setting the data type removed all the data points, so we must move them back to the metric.
+		dps.MoveAndAppendTo(metric.Sum().DataPoints())
 
 		return nil, nil
 	}, nil

processor/transformprocessor/internal/metrics/func_convert_gauge_to_sum_datapoint.go

@@ -50,8 +50,8 @@ func convertDatapointGaugeToSum(stringAggTemp string, monotonic bool) (ottl.Expr
 		metric.SetEmptySum().SetAggregationTemporality(aggTemp)
 		metric.Sum().SetIsMonotonic(monotonic)
 
-		// Setting the data type removed all the data points, so we must copy them back to the metric.
-		dps.CopyTo(metric.Sum().DataPoints())
+		// Setting the data type removed all the data points, so we must move them back to the metric.
+		dps.MoveAndAppendTo(metric.Sum().DataPoints())
 
 		return nil, nil
 	}, nil

processor/transformprocessor/internal/metrics/func_convert_sum_to_gauge.go

@@ -30,7 +30,7 @@ func convertSumToGauge() (ottl.ExprFunc[ottlmetric.TransformContext], error) {
 		dps := metric.Sum().DataPoints()
 
 		// Setting the data type removed all the data points, so we must copy them back to the metric.
-		dps.CopyTo(metric.SetEmptyGauge().DataPoints())
+		dps.MoveAndAppendTo(metric.SetEmptyGauge().DataPoints())
 
 		return nil, nil
 	}, nil

processor/transformprocessor/internal/metrics/func_convert_sum_to_gauge_datapoint.go

@@ -29,8 +29,8 @@ func convertDatapointSumToGauge() (ottl.ExprFunc[ottldatapoint.TransformContext]
 
 		dps := metric.Sum().DataPoints()
 
-		// Setting the data type removed all the data points, so we must copy them back to the metric.
-		dps.CopyTo(metric.SetEmptyGauge().DataPoints())
+		// Setting the data type removed all the data points, so we must move them back to the metric.
+		dps.MoveAndAppendTo(metric.SetEmptyGauge().DataPoints())
 
 		return nil, nil
 	}, nil

processor/transformprocessor/internal/metrics/func_extract_sum_metric.go

@@ -32,7 +32,7 @@ func createExtractSumMetricFunction(_ ottl.FunctionContext, oArgs ottl.Arguments
 	return extractSumMetric(args.Monotonic)
 }
 
-// this interface helps unify the logic for extracting data from different histogram types
+// SumCountDataPoint interface helps unify the logic for extracting data from different histogram types
 // all supported metric types' datapoints implement it
 type SumCountDataPoint interface {
 	Attributes() pcommon.Map