1 files changed, 282 insertions, 0 deletions
diff --git a/vendor/go.opentelemetry.io/otel/sdk/resource/resource.go b/vendor/go.opentelemetry.io/otel/sdk/resource/resource.go
new file mode 100644
index 000000000..c425ff05d
--- /dev/null
+++ b/vendor/go.opentelemetry.io/otel/sdk/resource/resource.go
@@ -0,0 +1,282 @@
+// 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"
+	"fmt"
+	"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)
+	}
+
+	resource, err := Detect(ctx, cfg.detectors...)
+
+	var err2 error
+	resource, err2 = Merge(resource, &Resource{schemaURL: cfg.schemaURL})
+	if err == nil {
+		err = err2
+	} else if err2 != nil {
+		err = fmt.Errorf("detecting resources: %s", []string{err.Error(), err2.Error()})
+	}
+
+	return resource, err
+}
+
+// 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/v1.0.1/specification/common/common.md#attributes
+	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/bad49c714a62da5493f2d1d9bafd7ebe8c8ce7eb/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)
+}