request

type DurationTracker interface {
	// Track measures time spent in the given function f and
	// aggregates measured duration using aggregateFunction.
	// if Track is invoked with f from multiple goroutines concurrently,
	// then f must be safe to be invoked concurrently by multiple goroutines.
	Track(f func())

	// TrackDuration tracks latency from the specified duration
	// and aggregate it using aggregateFunction
	TrackDuration(time.Duration)

	// GetLatency returns the total latency incurred so far
	GetLatency() time.Duration
}

type LatencyTrackers struct {
	// MutatingWebhookTracker tracks the latency incurred in mutating webhook(s).
	// Since mutating webhooks are done sequentially, latency
	// is aggregated using sum function.
	MutatingWebhookTracker DurationTracker

	// ValidatingWebhookTracker tracks the latency incurred in validating webhook(s).
	// Validate webhooks are done in parallel, so max function is used.
	ValidatingWebhookTracker DurationTracker

	// APFQueueWaitTracker tracks the latency incurred by queue wait times
	// from priority & fairness.
	APFQueueWaitTracker DurationTracker

	// StorageTracker tracks the latency incurred inside the storage layer,
	// it accounts for the time it takes to send data to the underlying
	// storage layer (etcd) and get the complete response back.
	// If a request involves N (N>=1) round trips to the underlying
	// stogare layer, the latency will account for the total duration
	// from these N round trips.
	// It does not include the time incurred in admission, or validation.
	StorageTracker DurationTracker

	// TransformTracker tracks the latency incurred in transforming the
	// response object(s) returned from the underlying storage layer.
	// This includes transforming the object to user's desired form
	// (ie. as Table), and also setting appropriate API level fields.
	// This does not include the latency incurred in serialization
	// (json or protobuf) of the response object or writing
	// of it to the http ResponseWriter object.
	TransformTracker DurationTracker

	// SerializationTracker tracks the latency incurred in serialization
	// (json or protobuf) of the response object.
	// NOTE: serialization and writing of the serialized raw bytes to the
	// associated http ResponseWriter object are interleaved, and hence
	// the latency measured here will include the time spent writing the
	// serialized raw bytes to the http ResponseWriter object.
	SerializationTracker DurationTracker

	// ResponseWriteTracker tracks the latency incurred in writing the
	// serialized raw bytes to the http ResponseWriter object (via the
	// Write method) associated with the request.
	// The Write method can be invoked multiple times, so we use a
	// latency tracker that sums up the duration from each call.
	ResponseWriteTracker DurationTracker

	// DecodeTracker is used to track latency incurred inside the function
	// that takes an object returned from the underlying storage layer
	// (etcd) and performs decoding of the response object.
	// When called multiple times, the latency incurred inside to
	// decode func each time will be summed up.
	DecodeTracker DurationTracker
}

type LongRunningRequestCheck func(r *http.Request, requestInfo *RequestInfo) bool

type RequestInfo struct {
	// IsResourceRequest indicates whether or not the request is for an API resource or subresource
	IsResourceRequest bool
	// Path is the URL path of the request
	Path string
	// Verb is the kube verb associated with the request for API requests, not the http verb.  This includes things like list and watch.
	// for non-resource requests, this is the lowercase http verb
	Verb string

	APIPrefix  string
	APIGroup   string
	APIVersion string
	Namespace  string
	// Resource is the name of the resource being requested.  This is not the kind.  For example: pods
	Resource string
	// Subresource is the name of the subresource being requested.  This is a different resource, scoped to the parent resource, but it may have a different kind.
	// For instance, /pods has the resource "pods" and the kind "Pod", while /pods/foo/status has the resource "pods", the sub resource "status", and the kind "Pod"
	// (because status operates on pods). The binding resource for a pod though may be /pods/foo/binding, which has resource "pods", subresource "binding", and kind "Binding".
	Subresource string
	// Name is empty for some verbs, but if the request directly indicates a name (not in body content) then this field is filled in.
	Name string
	// Parts are the path parts for the request, always starting with /{resource}/{name}
	Parts []string
}

type RequestInfoFactory struct {
	APIPrefixes          sets.String // without leading and trailing slashes
	GrouplessAPIPrefixes sets.String // without leading and trailing slashes
}

type RequestInfoResolver interface {
	NewRequestInfo(req *http.Request) (*RequestInfo, error)
}

type ServerShutdownSignal interface {
	// Signaled when the apiserver is not receiving any new request
	ShuttingDown() <-chan struct{}
}