chore: vendor

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/aggregate.go

@@ -0,0 +1,154 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
+
+import (
+	"context"
+	"time"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata"
+)
+
+// now is used to return the current local time while allowing tests to
+// override the default time.Now function.
+var now = time.Now
+
+// Measure receives measurements to be aggregated.
+type Measure[N int64 | float64] func(context.Context, N, attribute.Set)
+
+// ComputeAggregation stores the aggregate of measurements into dest and
+// returns the number of aggregate data-points output.
+type ComputeAggregation func(dest *metricdata.Aggregation) int
+
+// Builder builds an aggregate function.
+type Builder[N int64 | float64] struct {
+	// Temporality is the temporality used for the returned aggregate function.
+	//
+	// If this is not provided a default of cumulative will be used (except for
+	// the last-value aggregate function where delta is the only appropriate
+	// temporality).
+	Temporality metricdata.Temporality
+	// Filter is the attribute filter the aggregate function will use on the
+	// input of measurements.
+	Filter attribute.Filter
+	// ReservoirFunc is the factory function used by aggregate functions to
+	// create new exemplar reservoirs for a new seen attribute set.
+	//
+	// If this is not provided a default factory function that returns an
+	// exemplar.Drop reservoir will be used.
+	ReservoirFunc func() exemplar.FilteredReservoir[N]
+	// AggregationLimit is the cardinality limit of measurement attributes. Any
+	// measurement for new attributes once the limit has been reached will be
+	// aggregated into a single aggregate for the "otel.metric.overflow"
+	// attribute.
+	//
+	// If AggregationLimit is less than or equal to zero there will not be an
+	// aggregation limit imposed (i.e. unlimited attribute sets).
+	AggregationLimit int
+}
+
+func (b Builder[N]) resFunc() func() exemplar.FilteredReservoir[N] {
+	if b.ReservoirFunc != nil {
+		return b.ReservoirFunc
+	}
+
+	return exemplar.Drop
+}
+
+type fltrMeasure[N int64 | float64] func(ctx context.Context, value N, fltrAttr attribute.Set, droppedAttr []attribute.KeyValue)
+
+func (b Builder[N]) filter(f fltrMeasure[N]) Measure[N] {
+	if b.Filter != nil {
+		fltr := b.Filter // Copy to make it immutable after assignment.
+		return func(ctx context.Context, n N, a attribute.Set) {
+			fAttr, dropped := a.Filter(fltr)
+			f(ctx, n, fAttr, dropped)
+		}
+	}
+	return func(ctx context.Context, n N, a attribute.Set) {
+		f(ctx, n, a, nil)
+	}
+}
+
+// LastValue returns a last-value aggregate function input and output.
+func (b Builder[N]) LastValue() (Measure[N], ComputeAggregation) {
+	lv := newLastValue[N](b.AggregationLimit, b.resFunc())
+	switch b.Temporality {
+	case metricdata.DeltaTemporality:
+		return b.filter(lv.measure), lv.delta
+	default:
+		return b.filter(lv.measure), lv.cumulative
+	}
+}
+
+// PrecomputedLastValue returns a last-value aggregate function input and
+// output. The aggregation returned from the returned ComputeAggregation
+// function will always only return values from the previous collection cycle.
+func (b Builder[N]) PrecomputedLastValue() (Measure[N], ComputeAggregation) {
+	lv := newPrecomputedLastValue[N](b.AggregationLimit, b.resFunc())
+	switch b.Temporality {
+	case metricdata.DeltaTemporality:
+		return b.filter(lv.measure), lv.delta
+	default:
+		return b.filter(lv.measure), lv.cumulative
+	}
+}
+
+// PrecomputedSum returns a sum aggregate function input and output. The
+// arguments passed to the input are expected to be the precomputed sum values.
+func (b Builder[N]) PrecomputedSum(monotonic bool) (Measure[N], ComputeAggregation) {
+	s := newPrecomputedSum[N](monotonic, b.AggregationLimit, b.resFunc())
+	switch b.Temporality {
+	case metricdata.DeltaTemporality:
+		return b.filter(s.measure), s.delta
+	default:
+		return b.filter(s.measure), s.cumulative
+	}
+}
+
+// Sum returns a sum aggregate function input and output.
+func (b Builder[N]) Sum(monotonic bool) (Measure[N], ComputeAggregation) {
+	s := newSum[N](monotonic, b.AggregationLimit, b.resFunc())
+	switch b.Temporality {
+	case metricdata.DeltaTemporality:
+		return b.filter(s.measure), s.delta
+	default:
+		return b.filter(s.measure), s.cumulative
+	}
+}
+
+// ExplicitBucketHistogram returns a histogram aggregate function input and
+// output.
+func (b Builder[N]) ExplicitBucketHistogram(boundaries []float64, noMinMax, noSum bool) (Measure[N], ComputeAggregation) {
+	h := newHistogram[N](boundaries, noMinMax, noSum, b.AggregationLimit, b.resFunc())
+	switch b.Temporality {
+	case metricdata.DeltaTemporality:
+		return b.filter(h.measure), h.delta
+	default:
+		return b.filter(h.measure), h.cumulative
+	}
+}
+
+// ExponentialBucketHistogram returns a histogram aggregate function input and
+// output.
+func (b Builder[N]) ExponentialBucketHistogram(maxSize, maxScale int32, noMinMax, noSum bool) (Measure[N], ComputeAggregation) {
+	h := newExponentialHistogram[N](maxSize, maxScale, noMinMax, noSum, b.AggregationLimit, b.resFunc())
+	switch b.Temporality {
+	case metricdata.DeltaTemporality:
+		return b.filter(h.measure), h.delta
+	default:
+		return b.filter(h.measure), h.cumulative
+	}
+}
+
+// reset ensures s has capacity and sets it length. If the capacity of s too
+// small, a new slice is returned with the specified capacity and length.
+func reset[T any](s []T, length, capacity int) []T {
+	if cap(s) < capacity {
+		return make([]T, length, capacity)
+	}
+	return s[:length]
+}