trace

type CarrierFormat byte

type Config struct {
	Operation string
	Tags      map[string]interface{}
}

type Tracer interface {
	// Implement Start() and Stop() methods to manage tracer lifecycle. These methods will be called during engine startup and engine shutdown.
	managed.Managed

	// Name() returns the name of the registered tracer
	Name() string

	// Extract() returns a TracingContext given `format` and `carrier`.
	//
	// FlogoTracer defines a common set of `format` values, and each has an expected `carrier` type.
	//
	// After extracting the trace context from the incoming request, the trace context must be appended
	// to the go context to propogate it to the action handler.
	// See trace.AppendTracingContext() and trace.ExtractTracingContext().
	//
	// Example usage:
	//
	//	tr := trace.GetTracer()
	//	tctx, err := tr.Extract(trace.HTTPHeaders, httpReq)
	//	if err != nil {
	//		log.Errorf("failed to extract tracing context due to error: %s", err.Error())
	//	}
	//	ctx := trace.AppendTracingContext(context.Background(), tctx)
	//	..
	//	results, err := handler.Handle(ctx, outputData)
	Extract(format CarrierFormat, carrier interface{}) (TracingContext, error)

	// Inject() takes the tracing context `tctx` and injects the current trace context for
	// propagation within `carrier`. The actual type of `carrier` depends on the value of `format`.
	//
	// trace.Tracer defines a common set of `format` values, and each has an expected `carrier` type.
	//
	// Example usage:
	//
	// tracer := trace.GetTracer()
	// err = tracer.Inject(ctx.TracingContext(), trace.HTTPHeaders, req)
	Inject(tCtx TracingContext, format CarrierFormat, carrier interface{}) error

	// StartTrace() returns a wrapped implementation specific trace created by the underlying tracing implementation.
	// Non nil parent can be used to establish parent-child relationship between trace object.
	StartTrace(config Config, parent TracingContext) (TracingContext, error)

	// FinishTrace() finishes a wrapped implementation specific trace
	// Non nil error indicates failure
	FinishTrace(tContext TracingContext, err error) error
}

type TracingContext interface {
	// TraceObject() returns underlying tracing implementation
	TraceObject() interface{}
	// SetTags() allows you to set one or more tags to tracing object
	SetTags(tags map[string]interface{}) bool
	// SetTags() allows you to add tag to tracing object
	SetTag(tagKey string, tagValue interface{}) bool
	// LogKV() allows you to log additional details about the entity being traced
	LogKV(kvs map[string]interface{}) bool
}