71 lines
1.3 KiB
Go
71 lines
1.3 KiB
Go
// Package trace provides an interface for distributed tracing
|
|
package trace
|
|
|
|
import (
|
|
"context"
|
|
"time"
|
|
)
|
|
|
|
// Tracer is an interface for distributed tracing
|
|
type Tracer interface {
|
|
// Start a trace
|
|
Start(ctx context.Context, name string) (context.Context, *Span)
|
|
// Finish the trace
|
|
Finish(*Span) error
|
|
// Read the traces
|
|
Read(...ReadOption) ([]*Span, error)
|
|
}
|
|
|
|
// Span is used to record an entry
|
|
type Span struct {
|
|
// Id of the trace
|
|
Trace string
|
|
// name of the span
|
|
Name string
|
|
// id of the span
|
|
Id string
|
|
// parent span id
|
|
Parent string
|
|
// Start time
|
|
Started time.Time
|
|
// Duration in nano seconds
|
|
Duration time.Duration
|
|
// associated data
|
|
Metadata map[string]string
|
|
}
|
|
|
|
type spanKey struct{}
|
|
|
|
// FromContext returns a span from context
|
|
func FromContext(ctx context.Context) (*Span, bool) {
|
|
s, ok := ctx.Value(spanKey{}).(*Span)
|
|
return s, ok
|
|
}
|
|
|
|
// NewContext creates a new context with the span
|
|
func NewContext(ctx context.Context, s *Span) context.Context {
|
|
return context.WithValue(ctx, spanKey{}, s)
|
|
}
|
|
|
|
var (
|
|
DefaultTracer Tracer = new(noop)
|
|
)
|
|
|
|
type noop struct{}
|
|
|
|
func (n *noop) Init(...Option) error {
|
|
return nil
|
|
}
|
|
|
|
func (n *noop) Start(ctx context.Context, name string) (context.Context, *Span) {
|
|
return nil, nil
|
|
}
|
|
|
|
func (n *noop) Finish(*Span) error {
|
|
return nil
|
|
}
|
|
|
|
func (n *noop) Read(...ReadOption) ([]*Span, error) {
|
|
return nil, nil
|
|
}
|