distribution/vendor/go.opentelemetry.io/otel/sdk/metric/instrument.go

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// 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
}