proc

type BuildParams struct {
	Name   string
	Cfg    *service.Config
	Hosts  []*host.Host
	Stats  *Stats
	Logger log.Logger
}

type Builder interface {
	// Build builds a new processor.
	Build(params BuildParams) (Proc, error)
}

type CommonStats struct {
	CxTotal        *stats.Counter   // total connections
	CxDestroyTotal *stats.Counter   // destroyed connections
	CxActive       *stats.Gauge     // active connections
	CxLengthSec    *stats.Histogram // connection length
	CxRxBytesTotal *stats.Counter   // received connection bytes
	CxTxBytesTotal *stats.Counter   // sent connection bytes

	RqTotal         *stats.Counter   // total request
	RqSuccessTotal  *stats.Counter   // success request
	RqFailureTotal  *stats.Counter   // failed request
	RqActive        *stats.Gauge     // active request
	RqDurationMs    *stats.Histogram // request duration
	RqRxBytesLength *stats.Histogram // received request bytes length
	RqTxBytesLength *stats.Histogram // sent request bytes length
}

type ConnHandlerFunc func(conn net.Conn)

type DownstreamStats struct {
	*stats.Scope
	CommonStats
	CxRestricted *stats.Counter // restricted connections
}

type Listener interface {
	Address() string
	Serve() error
	Drain() error
	Stop() error
}

type Proc interface {
	Name() string
	Address() string
	Config() *service.Config

	OnSvcHostAdd([]*host.Host) error
	OnSvcHostRemove([]*host.Host) error
	OnSvcAllHostReplace([]*host.Host) error

	OnSvcConfigUpdate(*service.Config) error

	Start() error
	StopListen() error
	Stop() error
}

type Stats struct {
	*stats.Scope
	Downstream *DownstreamStats
	Upstream   *UpstreamStats
}

type UpstreamStats struct {
	*stats.Scope
	CommonStats
	CxConnectTimeout *stats.Counter // total connection connect timeouts
	CxConnectFail    *stats.Counter // total connection failures
}