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opentelemetry-go/sdk/metric/internal/lastvalue.go
Tyler Yahn d091ba88e4
Do not export aggregations without any data points (#3436)
* Return empty nil aggs if no meas

* Update tests with new expected behavior

* Add change to changelog

* Set PR number in changelog

* Run lint

* Fix pipeline_test

* Scope change in changelog to pkg

* Clean up init of agg types
2022-11-11 07:22:27 -08:00

75 lines
2.0 KiB
Go

// Copyright The OpenTelemetry Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package internal // import "go.opentelemetry.io/otel/sdk/metric/internal"
import (
"sync"
"time"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/sdk/metric/metricdata"
)
// datapoint is timestamped measurement data.
type datapoint[N int64 | float64] struct {
timestamp time.Time
value N
}
// lastValue summarizes a set of measurements as the last one made.
type lastValue[N int64 | float64] struct {
sync.Mutex
values map[attribute.Set]datapoint[N]
}
// NewLastValue returns an Aggregator that summarizes a set of measurements as
// the last one made.
func NewLastValue[N int64 | float64]() Aggregator[N] {
return &lastValue[N]{values: make(map[attribute.Set]datapoint[N])}
}
func (s *lastValue[N]) Aggregate(value N, attr attribute.Set) {
d := datapoint[N]{timestamp: now(), value: value}
s.Lock()
s.values[attr] = d
s.Unlock()
}
func (s *lastValue[N]) Aggregation() metricdata.Aggregation {
s.Lock()
defer s.Unlock()
if len(s.values) == 0 {
return nil
}
gauge := metricdata.Gauge[N]{
DataPoints: make([]metricdata.DataPoint[N], 0, len(s.values)),
}
for a, v := range s.values {
gauge.DataPoints = append(gauge.DataPoints, metricdata.DataPoint[N]{
Attributes: a,
// The event time is the only meaningful timestamp, StartTime is
// ignored.
Time: v.timestamp,
Value: v.value,
})
// Do not report stale values.
delete(s.values, a)
}
return gauge
}