distribution/vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/lastvalue.go
gotgelf 0e3018f2cf Otel tracing MVP: vendor changes
Signed-off-by: gotgelf <gotgelf@gmail.com>
2023-12-11 21:18:42 +01:00

68 lines
1.8 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 aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
import (
"context"
"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
}
func newLastValue[N int64 | float64]() *lastValue[N] {
return &lastValue[N]{values: make(map[attribute.Set]datapoint[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]
}
func (s *lastValue[N]) measure(ctx context.Context, value N, attr attribute.Set) {
d := datapoint[N]{timestamp: now(), value: value}
s.Lock()
s.values[attr] = d
s.Unlock()
}
func (s *lastValue[N]) computeAggregation(dest *[]metricdata.DataPoint[N]) {
s.Lock()
defer s.Unlock()
n := len(s.values)
*dest = reset(*dest, n, n)
var i int
for a, v := range s.values {
(*dest)[i].Attributes = a
// The event time is the only meaningful timestamp, StartTime is
// ignored.
(*dest)[i].Time = v.timestamp
(*dest)[i].Value = v.value
// Do not report stale values.
delete(s.values, a)
i++
}
}