gtsocial-umbx

resource.go (7810B)

---

 // 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 resource // import "go.opentelemetry.io/otel/sdk/resource"
 
 import (
 	"context"
 	"errors"
 	"sync"
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
 )
 
 // Resource describes an entity about which identifying information
 // and metadata is exposed.  Resource is an immutable object,
 // equivalent to a map from key to unique value.
 //
 // Resources should be passed and stored as pointers
 // (`*resource.Resource`).  The `nil` value is equivalent to an empty
 // Resource.
 type Resource struct {
 	attrs     attribute.Set
 	schemaURL string
 }
 
 var (
 	emptyResource       Resource
 	defaultResource     *Resource
 	defaultResourceOnce sync.Once
 )
 
 var errMergeConflictSchemaURL = errors.New("cannot merge resource due to conflicting Schema URL")
 
 // New returns a Resource combined from the user-provided detectors.
 func New(ctx context.Context, opts ...Option) (*Resource, error) {
 	cfg := config{}
 	for _, opt := range opts {
 		cfg = opt.apply(cfg)
 	}
 
 	r := &Resource{schemaURL: cfg.schemaURL}
 	return r, detect(ctx, r, cfg.detectors)
 }
 
 // NewWithAttributes creates a resource from attrs and associates the resource with a
 // schema URL. If attrs contains duplicate keys, the last value will be used. If attrs
 // contains any invalid items those items will be dropped. The attrs are assumed to be
 // in a schema identified by schemaURL.
 func NewWithAttributes(schemaURL string, attrs ...attribute.KeyValue) *Resource {
 	resource := NewSchemaless(attrs...)
 	resource.schemaURL = schemaURL
 	return resource
 }
 
 // NewSchemaless creates a resource from attrs. If attrs contains duplicate keys,
 // the last value will be used. If attrs contains any invalid items those items will
 // be dropped. The resource will not be associated with a schema URL. If the schema
 // of the attrs is known use NewWithAttributes instead.
 func NewSchemaless(attrs ...attribute.KeyValue) *Resource {
 	if len(attrs) == 0 {
 		return &emptyResource
 	}
 
 	// Ensure attributes comply with the specification:
 	// https://github.com/open-telemetry/opentelemetry-specification/blob/v1.20.0/specification/common/README.md#attribute
 	s, _ := attribute.NewSetWithFiltered(attrs, func(kv attribute.KeyValue) bool {
 		return kv.Valid()
 	})
 
 	// If attrs only contains invalid entries do not allocate a new resource.
 	if s.Len() == 0 {
 		return &emptyResource
 	}
 
 	return &Resource{attrs: s} //nolint
 }
 
 // String implements the Stringer interface and provides a
 // human-readable form of the resource.
 //
 // Avoid using this representation as the key in a map of resources,
 // use Equivalent() as the key instead.
 func (r *Resource) String() string {
 	if r == nil {
 		return ""
 	}
 	return r.attrs.Encoded(attribute.DefaultEncoder())
 }
 
 // MarshalLog is the marshaling function used by the logging system to represent this exporter.
 func (r *Resource) MarshalLog() interface{} {
 	return struct {
 		Attributes attribute.Set
 		SchemaURL  string
 	}{
 		Attributes: r.attrs,
 		SchemaURL:  r.schemaURL,
 	}
 }
 
 // Attributes returns a copy of attributes from the resource in a sorted order.
 // To avoid allocating a new slice, use an iterator.
 func (r *Resource) Attributes() []attribute.KeyValue {
 	if r == nil {
 		r = Empty()
 	}
 	return r.attrs.ToSlice()
 }
 
 // SchemaURL returns the schema URL associated with Resource r.
 func (r *Resource) SchemaURL() string {
 	if r == nil {
 		return ""
 	}
 	return r.schemaURL
 }
 
 // Iter returns an iterator of the Resource attributes.
 // This is ideal to use if you do not want a copy of the attributes.
 func (r *Resource) Iter() attribute.Iterator {
 	if r == nil {
 		r = Empty()
 	}
 	return r.attrs.Iter()
 }
 
 // Equal returns true when a Resource is equivalent to this Resource.
 func (r *Resource) Equal(eq *Resource) bool {
 	if r == nil {
 		r = Empty()
 	}
 	if eq == nil {
 		eq = Empty()
 	}
 	return r.Equivalent() == eq.Equivalent()
 }
 
 // Merge creates a new resource by combining resource a and b.
 //
 // If there are common keys between resource a and b, then the value
 // from resource b will overwrite the value from resource a, even
 // if resource b's value is empty.
 //
 // The SchemaURL of the resources will be merged according to the spec rules:
 // https://github.com/open-telemetry/opentelemetry-specification/blob/v1.20.0/specification/resource/sdk.md#merge
 // If the resources have different non-empty schemaURL an empty resource and an error
 // will be returned.
 func Merge(a, b *Resource) (*Resource, error) {
 	if a == nil && b == nil {
 		return Empty(), nil
 	}
 	if a == nil {
 		return b, nil
 	}
 	if b == nil {
 		return a, nil
 	}
 
 	// Merge the schema URL.
 	var schemaURL string
 	switch true {
 	case a.schemaURL == "":
 		schemaURL = b.schemaURL
 	case b.schemaURL == "":
 		schemaURL = a.schemaURL
 	case a.schemaURL == b.schemaURL:
 		schemaURL = a.schemaURL
 	default:
 		return Empty(), errMergeConflictSchemaURL
 	}
 
 	// Note: 'b' attributes will overwrite 'a' with last-value-wins in attribute.Key()
 	// Meaning this is equivalent to: append(a.Attributes(), b.Attributes()...)
 	mi := attribute.NewMergeIterator(b.Set(), a.Set())
 	combine := make([]attribute.KeyValue, 0, a.Len()+b.Len())
 	for mi.Next() {
 		combine = append(combine, mi.Attribute())
 	}
 	merged := NewWithAttributes(schemaURL, combine...)
 	return merged, nil
 }
 
 // Empty returns an instance of Resource with no attributes. It is
 // equivalent to a `nil` Resource.
 func Empty() *Resource {
 	return &emptyResource
 }
 
 // Default returns an instance of Resource with a default
 // "service.name" and OpenTelemetrySDK attributes.
 func Default() *Resource {
 	defaultResourceOnce.Do(func() {
 		var err error
 		defaultResource, err = Detect(
 			context.Background(),
 			defaultServiceNameDetector{},
 			fromEnv{},
 			telemetrySDK{},
 		)
 		if err != nil {
 			otel.Handle(err)
 		}
 		// If Detect did not return a valid resource, fall back to emptyResource.
 		if defaultResource == nil {
 			defaultResource = &emptyResource
 		}
 	})
 	return defaultResource
 }
 
 // Environment returns an instance of Resource with attributes
 // extracted from the OTEL_RESOURCE_ATTRIBUTES environment variable.
 func Environment() *Resource {
 	detector := &fromEnv{}
 	resource, err := detector.Detect(context.Background())
 	if err != nil {
 		otel.Handle(err)
 	}
 	return resource
 }
 
 // Equivalent returns an object that can be compared for equality
 // between two resources. This value is suitable for use as a key in
 // a map.
 func (r *Resource) Equivalent() attribute.Distinct {
 	return r.Set().Equivalent()
 }
 
 // Set returns the equivalent *attribute.Set of this resource's attributes.
 func (r *Resource) Set() *attribute.Set {
 	if r == nil {
 		r = Empty()
 	}
 	return &r.attrs
 }
 
 // MarshalJSON encodes the resource attributes as a JSON list of { "Key":
 // "...", "Value": ... } pairs in order sorted by key.
 func (r *Resource) MarshalJSON() ([]byte, error) {
 	if r == nil {
 		r = Empty()
 	}
 	return r.attrs.MarshalJSON()
 }
 
 // Len returns the number of unique key-values in this Resource.
 func (r *Resource) Len() int {
 	if r == nil {
 		return 0
 	}
 	return r.attrs.Len()
 }
 
 // Encoded returns an encoded representation of the resource.
 func (r *Resource) Encoded(enc attribute.Encoder) string {
 	if r == nil {
 		return ""
 	}
 	return r.attrs.Encoded(enc)
 }