GoToSocial/vendor/go.opentelemetry.io/otel/trace/span.go
2024-08-26 18:05:54 +02:00

178 lines
6.8 KiB
Go

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
package trace // import "go.opentelemetry.io/otel/trace"
import (
"context"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/codes"
"go.opentelemetry.io/otel/trace/embedded"
)
// Span is the individual component of a trace. It represents a single named
// and timed operation of a workflow that is traced. A Tracer is used to
// create a Span and it is then up to the operation the Span represents to
// properly end the Span when the operation itself ends.
//
// Warning: Methods may be added to this interface in minor releases. See
// package documentation on API implementation for information on how to set
// default behavior for unimplemented methods.
type Span interface {
// Users of the interface can ignore this. This embedded type is only used
// by implementations of this interface. See the "API Implementations"
// section of the package documentation for more information.
embedded.Span
// End completes the Span. The Span is considered complete and ready to be
// delivered through the rest of the telemetry pipeline after this method
// is called. Therefore, updates to the Span are not allowed after this
// method has been called.
End(options ...SpanEndOption)
// AddEvent adds an event with the provided name and options.
AddEvent(name string, options ...EventOption)
// AddLink adds a link.
// Adding links at span creation using WithLinks is preferred to calling AddLink
// later, for contexts that are available during span creation, because head
// sampling decisions can only consider information present during span creation.
AddLink(link Link)
// IsRecording returns the recording state of the Span. It will return
// true if the Span is active and events can be recorded.
IsRecording() bool
// RecordError will record err as an exception span event for this span. An
// additional call to SetStatus is required if the Status of the Span should
// be set to Error, as this method does not change the Span status. If this
// span is not being recorded or err is nil then this method does nothing.
RecordError(err error, options ...EventOption)
// SpanContext returns the SpanContext of the Span. The returned SpanContext
// is usable even after the End method has been called for the Span.
SpanContext() SpanContext
// SetStatus sets the status of the Span in the form of a code and a
// description, provided the status hasn't already been set to a higher
// value before (OK > Error > Unset). The description is only included in a
// status when the code is for an error.
SetStatus(code codes.Code, description string)
// SetName sets the Span name.
SetName(name string)
// SetAttributes sets kv as attributes of the Span. If a key from kv
// already exists for an attribute of the Span it will be overwritten with
// the value contained in kv.
SetAttributes(kv ...attribute.KeyValue)
// TracerProvider returns a TracerProvider that can be used to generate
// additional Spans on the same telemetry pipeline as the current Span.
TracerProvider() TracerProvider
}
// Link is the relationship between two Spans. The relationship can be within
// the same Trace or across different Traces.
//
// For example, a Link is used in the following situations:
//
// 1. Batch Processing: A batch of operations may contain operations
// associated with one or more traces/spans. Since there can only be one
// parent SpanContext, a Link is used to keep reference to the
// SpanContext of all operations in the batch.
// 2. Public Endpoint: A SpanContext for an in incoming client request on a
// public endpoint should be considered untrusted. In such a case, a new
// trace with its own identity and sampling decision needs to be created,
// but this new trace needs to be related to the original trace in some
// form. A Link is used to keep reference to the original SpanContext and
// track the relationship.
type Link struct {
// SpanContext of the linked Span.
SpanContext SpanContext
// Attributes describe the aspects of the link.
Attributes []attribute.KeyValue
}
// LinkFromContext returns a link encapsulating the SpanContext in the provided
// ctx.
func LinkFromContext(ctx context.Context, attrs ...attribute.KeyValue) Link {
return Link{
SpanContext: SpanContextFromContext(ctx),
Attributes: attrs,
}
}
// SpanKind is the role a Span plays in a Trace.
type SpanKind int
// As a convenience, these match the proto definition, see
// https://github.com/open-telemetry/opentelemetry-proto/blob/30d237e1ff3ab7aa50e0922b5bebdd93505090af/opentelemetry/proto/trace/v1/trace.proto#L101-L129
//
// The unspecified value is not a valid `SpanKind`. Use `ValidateSpanKind()`
// to coerce a span kind to a valid value.
const (
// SpanKindUnspecified is an unspecified SpanKind and is not a valid
// SpanKind. SpanKindUnspecified should be replaced with SpanKindInternal
// if it is received.
SpanKindUnspecified SpanKind = 0
// SpanKindInternal is a SpanKind for a Span that represents an internal
// operation within an application.
SpanKindInternal SpanKind = 1
// SpanKindServer is a SpanKind for a Span that represents the operation
// of handling a request from a client.
SpanKindServer SpanKind = 2
// SpanKindClient is a SpanKind for a Span that represents the operation
// of client making a request to a server.
SpanKindClient SpanKind = 3
// SpanKindProducer is a SpanKind for a Span that represents the operation
// of a producer sending a message to a message broker. Unlike
// SpanKindClient and SpanKindServer, there is often no direct
// relationship between this kind of Span and a SpanKindConsumer kind. A
// SpanKindProducer Span will end once the message is accepted by the
// message broker which might not overlap with the processing of that
// message.
SpanKindProducer SpanKind = 4
// SpanKindConsumer is a SpanKind for a Span that represents the operation
// of a consumer receiving a message from a message broker. Like
// SpanKindProducer Spans, there is often no direct relationship between
// this Span and the Span that produced the message.
SpanKindConsumer SpanKind = 5
)
// ValidateSpanKind returns a valid span kind value. This will coerce
// invalid values into the default value, SpanKindInternal.
func ValidateSpanKind(spanKind SpanKind) SpanKind {
switch spanKind {
case SpanKindInternal,
SpanKindServer,
SpanKindClient,
SpanKindProducer,
SpanKindConsumer:
// valid
return spanKind
default:
return SpanKindInternal
}
}
// String returns the specified name of the SpanKind in lower-case.
func (sk SpanKind) String() string {
switch sk {
case SpanKindInternal:
return "internal"
case SpanKindServer:
return "server"
case SpanKindClient:
return "client"
case SpanKindProducer:
return "producer"
case SpanKindConsumer:
return "consumer"
default:
return "unspecified"
}
}