1// Copyright The OpenTelemetry Authors
 2// SPDX-License-Identifier: Apache-2.0
 3
 4package metric // import "go.opentelemetry.io/otel/metric"
 5
 6import "go.opentelemetry.io/otel/attribute"
 7
 8// MeterConfig contains options for Meters.
 9type MeterConfig struct {
10	instrumentationVersion string
11	schemaURL              string
12	attrs                  attribute.Set
13
14	// Ensure forward compatibility by explicitly making this not comparable.
15	noCmp [0]func() //nolint: unused  // This is indeed used.
16}
17
18// InstrumentationVersion returns the version of the library providing
19// instrumentation.
20func (cfg MeterConfig) InstrumentationVersion() string {
21	return cfg.instrumentationVersion
22}
23
24// InstrumentationAttributes returns the attributes associated with the library
25// providing instrumentation.
26func (cfg MeterConfig) InstrumentationAttributes() attribute.Set {
27	return cfg.attrs
28}
29
30// SchemaURL is the schema_url of the library providing instrumentation.
31func (cfg MeterConfig) SchemaURL() string {
32	return cfg.schemaURL
33}
34
35// MeterOption is an interface for applying Meter options.
36type MeterOption interface {
37	// applyMeter is used to set a MeterOption value of a MeterConfig.
38	applyMeter(MeterConfig) MeterConfig
39}
40
41// NewMeterConfig creates a new MeterConfig and applies
42// all the given options.
43func NewMeterConfig(opts ...MeterOption) MeterConfig {
44	var config MeterConfig
45	for _, o := range opts {
46		config = o.applyMeter(config)
47	}
48	return config
49}
50
51type meterOptionFunc func(MeterConfig) MeterConfig
52
53func (fn meterOptionFunc) applyMeter(cfg MeterConfig) MeterConfig {
54	return fn(cfg)
55}
56
57// WithInstrumentationVersion sets the instrumentation version.
58func WithInstrumentationVersion(version string) MeterOption {
59	return meterOptionFunc(func(config MeterConfig) MeterConfig {
60		config.instrumentationVersion = version
61		return config
62	})
63}
64
65// WithInstrumentationAttributes sets the instrumentation attributes.
66//
67// The passed attributes will be de-duplicated.
68func WithInstrumentationAttributes(attr ...attribute.KeyValue) MeterOption {
69	return meterOptionFunc(func(config MeterConfig) MeterConfig {
70		config.attrs = attribute.NewSet(attr...)
71		return config
72	})
73}
74
75// WithSchemaURL sets the schema URL.
76func WithSchemaURL(schemaURL string) MeterOption {
77	return meterOptionFunc(func(config MeterConfig) MeterConfig {
78		config.schemaURL = schemaURL
79		return config
80	})
81}