server

type Dependency struct {
	Parent string
	Child  string
	Count  uint64
}

type Purger interface {
	Purge(before time.Time) error
}

type Query struct {
	// Only return traces that started at or after this time.
	StartTime time.Time
	// Only return traces that finished before or at this time.
	FinishTime time.Time
	// Only return traces where a span has this operation name.
	OperationName string
	// Only return traces that lasted at least this long.
	MinDuration time.Duration
	// Only return traces that lasted at most this long.
	MaxDuration time.Duration
	// Only return traces where all spans combined have all of these
	// tags.
	AndTags []QueryTag
	// Only return traces where all spans combined have at least one
	// of these tags.
	OrTags []QueryTag
	// How many traces to return. Zero means no limit.
	Num int
	// ServiceNames to filter by.
	ServiceNames []string
}

type QueryTag struct {
	// The key of the tag.
	Key string
	// The value of the tag.
	Value string
	// Whether the value should be checked for.
	CheckValue bool
}

type QueryTransport interface {
	// Start starts the transport.
	Start() error
}

type QueryTransportEngine func(srv *Server, conf map[string]interface{}) (QueryTransport, error)

type Queryer interface {
	// TraceByID returns a trace with a specific ID.
	TraceByID(id uint64) (tracer.RawTrace, error)
	// SpanByID returns a span with a specific ID.
	SpanByID(id uint64) (tracer.RawSpan, error)
	// QueryTraces returns all traces that match a query.
	QueryTraces(q Query) ([]tracer.RawTrace, error)

	// Services returns a list of all services.
	Services() ([]string, error)
	// Operations returns a list of all operations.
	Operations(service string) ([]string, error)
	// Dependencies returns the dependencies between services.
	Dependencies() ([]Dependency, error)
}

type Server struct {
	Storage          Storage
	StorageTransport StorageTransport
	QueryTransports  []QueryTransport
}

type Storage interface {
	tracer.Storer
	Queryer
}

type StorageEngine func(conf map[string]interface{}) (Storage, error)

type StorageTransport interface {
	// Start starts the transport.
	Start() error
}

type StorageTransportEngine func(srv *Server, conf map[string]interface{}) (StorageTransport, error)