github.com/facebookincubator/go-belt@v0.0.0-20230703220935-39cd348f1a38/tool/experimental/tracer/tracer.go

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package tracer

import (
	"context"

	"github.com/facebookincubator/go-belt"
	"github.com/facebookincubator/go-belt/pkg/field"
)

// Tracer is a generic abstract distributed tracing system client.
type Tracer interface {
	belt.Tool

	// Start creates a new Span, given its name, parent and options.
	Start(name string, parent Span, options ...SpanOption) Span

	// StartWithBelt creates a new root Span, given Belt, name and options.
	//
	// The returned Belt is a derivative of the provided one, with the Span added.
	StartWithBelt(belt *belt.Belt, name string, options ...SpanOption) (Span, *belt.Belt)

	// StartChildWithBelt creates a new child Span, given Belt, name and options.
	// The parent is extracted from the Belt. If one is not set in there then it is
	// an equivalent of StartWithBelt (a nil parent is used).
	//
	// The returned Belt is a derivative of the provided one, with the Span added.
	StartChildWithBelt(belt *belt.Belt, name string, options ...SpanOption) (Span, *belt.Belt)

	// StartWithCtx creates a new root Span, given Context, name and options.
	//
	// The returned Context is a derivative of the provided one, with the Span added.
	// Some implementations also injects a span structure with a specific key to the context.
	StartWithCtx(ctx context.Context, name string, options ...SpanOption) (Span, context.Context)

	// StartChildWithCtx creates a new child Span, given Context, name and options.
	// The parent is extracted from the Belt from the Context.
	// If one is not set in there then it is an equivalent of StartWithCtx (a nil parent is used).
	//
	// The returned Context is a derivative of the provided one, with the Span added.
	// Some implementations also injects a span structure with a specific key to the context.
	StartChildWithCtx(ctx context.Context, name string, options ...SpanOption) (Span, context.Context)

	// WithPreHooks returns a Tracer which includes/appends pre-hooks from the arguments.
	//
	// PreHook is the same as "Hook", but executed on early stages of building a Span
	// (before heavy computations).
	//
	// Special case: to reset hooks use `WithPreHooks()` (without any arguments).
	WithPreHooks(...Hook) Tracer

	// WithHooks returns a Tracer which includes/appends hooks from the arguments.
	//
	// See also description of "Hook".
	//
	// Special case: to reset hooks use `WithHooks()` (without any arguments).
	WithHooks(...Hook) Tracer
}

// WithField adds a Tracer derivative with the field added.
func WithField(t Tracer, key field.Key, value field.Value) Tracer {
	return t.WithContextFields(field.NewChainFromOne(key, value), 1).(Tracer)
}