78 lines
2.6 KiB
Go
78 lines
2.6 KiB
Go
// 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 autoexport // import "go.opentelemetry.io/contrib/exporters/autoexport"
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"sync"
|
|
)
|
|
|
|
const otelExporterOTLPProtoEnvKey = "OTEL_EXPORTER_OTLP_PROTOCOL"
|
|
|
|
// registry maintains a map of exporter names to exporter factories
|
|
// func(context.Context) (T, error) that is safe for concurrent use by multiple
|
|
// goroutines without additional locking or coordination.
|
|
type registry[T any] struct {
|
|
mu sync.Mutex
|
|
names map[string]func(context.Context) (T, error)
|
|
}
|
|
|
|
var (
|
|
// errUnknownExporter is returned when an unknown exporter name is used in
|
|
// the OTEL_*_EXPORTER environment variables.
|
|
errUnknownExporter = errors.New("unknown exporter")
|
|
|
|
// errInvalidOTLPProtocol is returned when an invalid protocol is used in
|
|
// the OTEL_EXPORTER_OTLP_PROTOCOL environment variable.
|
|
errInvalidOTLPProtocol = errors.New("invalid OTLP protocol - should be one of ['grpc', 'http/protobuf']")
|
|
|
|
// errDuplicateRegistration is returned when an duplicate registration is detected.
|
|
errDuplicateRegistration = errors.New("duplicate registration")
|
|
)
|
|
|
|
// load returns tries to find the exporter factory with the key and
|
|
// then execute the factory, returning the created SpanExporter.
|
|
// errUnknownExporter is returned if the registration is missing and the error from
|
|
// executing the factory if not nil.
|
|
func (r *registry[T]) load(ctx context.Context, key string) (T, error) {
|
|
r.mu.Lock()
|
|
defer r.mu.Unlock()
|
|
factory, ok := r.names[key]
|
|
if !ok {
|
|
var zero T
|
|
return zero, errUnknownExporter
|
|
}
|
|
return factory(ctx)
|
|
}
|
|
|
|
// store sets the factory for a key if is not already in the registry. errDuplicateRegistration
|
|
// is returned if the registry already contains key.
|
|
func (r *registry[T]) store(key string, factory func(context.Context) (T, error)) error {
|
|
r.mu.Lock()
|
|
defer r.mu.Unlock()
|
|
if _, ok := r.names[key]; ok {
|
|
return fmt.Errorf("%w: %q", errDuplicateRegistration, key)
|
|
}
|
|
r.names[key] = factory
|
|
return nil
|
|
}
|
|
|
|
func must(err error) {
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
}
|