1 files changed, 348 insertions, 0 deletions
diff --git a/vendor/go.opentelemetry.io/otel/sdk/metric/instrument.go b/vendor/go.opentelemetry.io/otel/sdk/metric/instrument.go
new file mode 100644
index 000000000..bb52f6ec7
--- /dev/null
+++ b/vendor/go.opentelemetry.io/otel/sdk/metric/instrument.go
@@ -0,0 +1,348 @@
+// 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.
+
+//go:generate stringer -type=InstrumentKind -trimprefix=InstrumentKind
+
+package metric // import "go.opentelemetry.io/otel/sdk/metric"
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/embedded"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	"go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
+)
+
+var (
+	zeroInstrumentKind InstrumentKind
+	zeroScope          instrumentation.Scope
+)
+
+// InstrumentKind is the identifier of a group of instruments that all
+// performing the same function.
+type InstrumentKind uint8
+
+const (
+	// instrumentKindUndefined is an undefined instrument kind, it should not
+	// be used by any initialized type.
+	instrumentKindUndefined InstrumentKind = iota // nolint:deadcode,varcheck,unused
+	// InstrumentKindCounter identifies a group of instruments that record
+	// increasing values synchronously with the code path they are measuring.
+	InstrumentKindCounter
+	// InstrumentKindUpDownCounter identifies a group of instruments that
+	// record increasing and decreasing values synchronously with the code path
+	// they are measuring.
+	InstrumentKindUpDownCounter
+	// InstrumentKindHistogram identifies a group of instruments that record a
+	// distribution of values synchronously with the code path they are
+	// measuring.
+	InstrumentKindHistogram
+	// InstrumentKindObservableCounter identifies a group of instruments that
+	// record increasing values in an asynchronous callback.
+	InstrumentKindObservableCounter
+	// InstrumentKindObservableUpDownCounter identifies a group of instruments
+	// that record increasing and decreasing values in an asynchronous
+	// callback.
+	InstrumentKindObservableUpDownCounter
+	// InstrumentKindObservableGauge identifies a group of instruments that
+	// record current values in an asynchronous callback.
+	InstrumentKindObservableGauge
+)
+
+type nonComparable [0]func() // nolint: unused  // This is indeed used.
+
+// Instrument describes properties an instrument is created with.
+type Instrument struct {
+	// Name is the human-readable identifier of the instrument.
+	Name string
+	// Description describes the purpose of the instrument.
+	Description string
+	// Kind defines the functional group of the instrument.
+	Kind InstrumentKind
+	// Unit is the unit of measurement recorded by the instrument.
+	Unit string
+	// Scope identifies the instrumentation that created the instrument.
+	Scope instrumentation.Scope
+
+	// Ensure forward compatibility if non-comparable fields need to be added.
+	nonComparable // nolint: unused
+}
+
+// empty returns if all fields of i are their zero-value.
+func (i Instrument) empty() bool {
+	return i.Name == "" &&
+		i.Description == "" &&
+		i.Kind == zeroInstrumentKind &&
+		i.Unit == "" &&
+		i.Scope == zeroScope
+}
+
+// matches returns whether all the non-zero-value fields of i match the
+// corresponding fields of other. If i is empty it will match all other, and
+// true will always be returned.
+func (i Instrument) matches(other Instrument) bool {
+	return i.matchesName(other) &&
+		i.matchesDescription(other) &&
+		i.matchesKind(other) &&
+		i.matchesUnit(other) &&
+		i.matchesScope(other)
+}
+
+// matchesName returns true if the Name of i is "" or it equals the Name of
+// other, otherwise false.
+func (i Instrument) matchesName(other Instrument) bool {
+	return i.Name == "" || i.Name == other.Name
+}
+
+// matchesDescription returns true if the Description of i is "" or it equals
+// the Description of other, otherwise false.
+func (i Instrument) matchesDescription(other Instrument) bool {
+	return i.Description == "" || i.Description == other.Description
+}
+
+// matchesKind returns true if the Kind of i is its zero-value or it equals the
+// Kind of other, otherwise false.
+func (i Instrument) matchesKind(other Instrument) bool {
+	return i.Kind == zeroInstrumentKind || i.Kind == other.Kind
+}
+
+// matchesUnit returns true if the Unit of i is its zero-value or it equals the
+// Unit of other, otherwise false.
+func (i Instrument) matchesUnit(other Instrument) bool {
+	return i.Unit == "" || i.Unit == other.Unit
+}
+
+// matchesScope returns true if the Scope of i is its zero-value or it equals
+// the Scope of other, otherwise false.
+func (i Instrument) matchesScope(other Instrument) bool {
+	return (i.Scope.Name == "" || i.Scope.Name == other.Scope.Name) &&
+		(i.Scope.Version == "" || i.Scope.Version == other.Scope.Version) &&
+		(i.Scope.SchemaURL == "" || i.Scope.SchemaURL == other.Scope.SchemaURL)
+}
+
+// Stream describes the stream of data an instrument produces.
+type Stream struct {
+	// Name is the human-readable identifier of the stream.
+	Name string
+	// Description describes the purpose of the data.
+	Description string
+	// Unit is the unit of measurement recorded.
+	Unit string
+	// Aggregation the stream uses for an instrument.
+	Aggregation Aggregation
+	// AttributeFilter is an attribute Filter applied to the attributes
+	// recorded for an instrument's measurement. If the filter returns false
+	// the attribute will not be recorded, otherwise, if it returns true, it
+	// will record the attribute.
+	//
+	// Use NewAllowKeysFilter from "go.opentelemetry.io/otel/attribute" to
+	// provide an allow-list of attribute keys here.
+	AttributeFilter attribute.Filter
+}
+
+// instID are the identifying properties of a instrument.
+type instID struct {
+	// Name is the name of the stream.
+	Name string
+	// Description is the description of the stream.
+	Description string
+	// Kind defines the functional group of the instrument.
+	Kind InstrumentKind
+	// Unit is the unit of the stream.
+	Unit string
+	// Number is the number type of the stream.
+	Number string
+}
+
+// Returns a normalized copy of the instID i.
+//
+// Instrument names are considered case-insensitive. Standardize the instrument
+// name to always be lowercase for the returned instID so it can be compared
+// without the name casing affecting the comparison.
+func (i instID) normalize() instID {
+	i.Name = strings.ToLower(i.Name)
+	return i
+}
+
+type int64Inst struct {
+	measures []aggregate.Measure[int64]
+
+	embedded.Int64Counter
+	embedded.Int64UpDownCounter
+	embedded.Int64Histogram
+}
+
+var (
+	_ metric.Int64Counter       = (*int64Inst)(nil)
+	_ metric.Int64UpDownCounter = (*int64Inst)(nil)
+	_ metric.Int64Histogram     = (*int64Inst)(nil)
+)
+
+func (i *int64Inst) Add(ctx context.Context, val int64, opts ...metric.AddOption) {
+	c := metric.NewAddConfig(opts)
+	i.aggregate(ctx, val, c.Attributes())
+}
+
+func (i *int64Inst) Record(ctx context.Context, val int64, opts ...metric.RecordOption) {
+	c := metric.NewRecordConfig(opts)
+	i.aggregate(ctx, val, c.Attributes())
+}
+
+func (i *int64Inst) aggregate(ctx context.Context, val int64, s attribute.Set) { // nolint:revive  // okay to shadow pkg with method.
+	if err := ctx.Err(); err != nil {
+		return
+	}
+	for _, in := range i.measures {
+		in(ctx, val, s)
+	}
+}
+
+type float64Inst struct {
+	measures []aggregate.Measure[float64]
+
+	embedded.Float64Counter
+	embedded.Float64UpDownCounter
+	embedded.Float64Histogram
+}
+
+var (
+	_ metric.Float64Counter       = (*float64Inst)(nil)
+	_ metric.Float64UpDownCounter = (*float64Inst)(nil)
+	_ metric.Float64Histogram     = (*float64Inst)(nil)
+)
+
+func (i *float64Inst) Add(ctx context.Context, val float64, opts ...metric.AddOption) {
+	c := metric.NewAddConfig(opts)
+	i.aggregate(ctx, val, c.Attributes())
+}
+
+func (i *float64Inst) Record(ctx context.Context, val float64, opts ...metric.RecordOption) {
+	c := metric.NewRecordConfig(opts)
+	i.aggregate(ctx, val, c.Attributes())
+}
+
+func (i *float64Inst) aggregate(ctx context.Context, val float64, s attribute.Set) {
+	if err := ctx.Err(); err != nil {
+		return
+	}
+	for _, in := range i.measures {
+		in(ctx, val, s)
+	}
+}
+
+// observablID is a comparable unique identifier of an observable.
+type observablID[N int64 | float64] struct {
+	name        string
+	description string
+	kind        InstrumentKind
+	unit        string
+	scope       instrumentation.Scope
+}
+
+type float64Observable struct {
+	metric.Float64Observable
+	*observable[float64]
+
+	embedded.Float64ObservableCounter
+	embedded.Float64ObservableUpDownCounter
+	embedded.Float64ObservableGauge
+}
+
+var (
+	_ metric.Float64ObservableCounter       = float64Observable{}
+	_ metric.Float64ObservableUpDownCounter = float64Observable{}
+	_ metric.Float64ObservableGauge         = float64Observable{}
+)
+
+func newFloat64Observable(m *meter, kind InstrumentKind, name, desc, u string, meas []aggregate.Measure[float64]) float64Observable {
+	return float64Observable{
+		observable: newObservable(m, kind, name, desc, u, meas),
+	}
+}
+
+type int64Observable struct {
+	metric.Int64Observable
+	*observable[int64]
+
+	embedded.Int64ObservableCounter
+	embedded.Int64ObservableUpDownCounter
+	embedded.Int64ObservableGauge
+}
+
+var (
+	_ metric.Int64ObservableCounter       = int64Observable{}
+	_ metric.Int64ObservableUpDownCounter = int64Observable{}
+	_ metric.Int64ObservableGauge         = int64Observable{}
+)
+
+func newInt64Observable(m *meter, kind InstrumentKind, name, desc, u string, meas []aggregate.Measure[int64]) int64Observable {
+	return int64Observable{
+		observable: newObservable(m, kind, name, desc, u, meas),
+	}
+}
+
+type observable[N int64 | float64] struct {
+	metric.Observable
+	observablID[N]
+
+	meter    *meter
+	measures []aggregate.Measure[N]
+}
+
+func newObservable[N int64 | float64](m *meter, kind InstrumentKind, name, desc, u string, meas []aggregate.Measure[N]) *observable[N] {
+	return &observable[N]{
+		observablID: observablID[N]{
+			name:        name,
+			description: desc,
+			kind:        kind,
+			unit:        u,
+			scope:       m.scope,
+		},
+		meter:    m,
+		measures: meas,
+	}
+}
+
+// observe records the val for the set of attrs.
+func (o *observable[N]) observe(val N, s attribute.Set) {
+	for _, in := range o.measures {
+		in(context.Background(), val, s)
+	}
+}
+
+var errEmptyAgg = errors.New("no aggregators for observable instrument")
+
+// registerable returns an error if the observable o should not be registered,
+// and nil if it should. An errEmptyAgg error is returned if o is effectively a
+// no-op because it does not have any aggregators. Also, an error is returned
+// if scope defines a Meter other than the one o was created by.
+func (o *observable[N]) registerable(m *meter) error {
+	if len(o.measures) == 0 {
+		return errEmptyAgg
+	}
+	if m != o.meter {
+		return fmt.Errorf(
+			"invalid registration: observable %q from Meter %q, registered with Meter %q",
+			o.name,
+			o.scope.Name,
+			m.scope.Name,
+		)
+	}
+	return nil
+}