1 files changed, 315 insertions, 0 deletions
diff --git a/vendor/github.com/docker/go-metrics/namespace.go b/vendor/github.com/docker/go-metrics/namespace.go
new file mode 100644
index 000000000..798315451
--- /dev/null
+++ b/vendor/github.com/docker/go-metrics/namespace.go
@@ -0,0 +1,315 @@
+package metrics
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type Labels map[string]string
+
+// NewNamespace returns a namespaces that is responsible for managing a collection of
+// metrics for a particual namespace and subsystem
+//
+// labels allows const labels to be added to all metrics created in this namespace
+// and are commonly used for data like application version and git commit
+func NewNamespace(name, subsystem string, labels Labels) *Namespace {
+	if labels == nil {
+		labels = make(map[string]string)
+	}
+	return &Namespace{
+		name:      name,
+		subsystem: subsystem,
+		labels:    labels,
+	}
+}
+
+// Namespace describes a set of metrics that share a namespace and subsystem.
+type Namespace struct {
+	name      string
+	subsystem string
+	labels    Labels
+	mu        sync.Mutex
+	metrics   []prometheus.Collector
+}
+
+// WithConstLabels returns a namespace with the provided set of labels merged
+// with the existing constant labels on the namespace.
+//
+//  Only metrics created with the returned namespace will get the new constant
+//  labels.  The returned namespace must be registered separately.
+func (n *Namespace) WithConstLabels(labels Labels) *Namespace {
+	n.mu.Lock()
+	ns := &Namespace{
+		name:      n.name,
+		subsystem: n.subsystem,
+		labels:    mergeLabels(n.labels, labels),
+	}
+	n.mu.Unlock()
+	return ns
+}
+
+func (n *Namespace) NewCounter(name, help string) Counter {
+	c := &counter{pc: prometheus.NewCounter(n.newCounterOpts(name, help))}
+	n.Add(c)
+	return c
+}
+
+func (n *Namespace) NewLabeledCounter(name, help string, labels ...string) LabeledCounter {
+	c := &labeledCounter{pc: prometheus.NewCounterVec(n.newCounterOpts(name, help), labels)}
+	n.Add(c)
+	return c
+}
+
+func (n *Namespace) newCounterOpts(name, help string) prometheus.CounterOpts {
+	return prometheus.CounterOpts{
+		Namespace:   n.name,
+		Subsystem:   n.subsystem,
+		Name:        makeName(name, Total),
+		Help:        help,
+		ConstLabels: prometheus.Labels(n.labels),
+	}
+}
+
+func (n *Namespace) NewTimer(name, help string) Timer {
+	t := &timer{
+		m: prometheus.NewHistogram(n.newTimerOpts(name, help)),
+	}
+	n.Add(t)
+	return t
+}
+
+func (n *Namespace) NewLabeledTimer(name, help string, labels ...string) LabeledTimer {
+	t := &labeledTimer{
+		m: prometheus.NewHistogramVec(n.newTimerOpts(name, help), labels),
+	}
+	n.Add(t)
+	return t
+}
+
+func (n *Namespace) newTimerOpts(name, help string) prometheus.HistogramOpts {
+	return prometheus.HistogramOpts{
+		Namespace:   n.name,
+		Subsystem:   n.subsystem,
+		Name:        makeName(name, Seconds),
+		Help:        help,
+		ConstLabels: prometheus.Labels(n.labels),
+	}
+}
+
+func (n *Namespace) NewGauge(name, help string, unit Unit) Gauge {
+	g := &gauge{
+		pg: prometheus.NewGauge(n.newGaugeOpts(name, help, unit)),
+	}
+	n.Add(g)
+	return g
+}
+
+func (n *Namespace) NewLabeledGauge(name, help string, unit Unit, labels ...string) LabeledGauge {
+	g := &labeledGauge{
+		pg: prometheus.NewGaugeVec(n.newGaugeOpts(name, help, unit), labels),
+	}
+	n.Add(g)
+	return g
+}
+
+func (n *Namespace) newGaugeOpts(name, help string, unit Unit) prometheus.GaugeOpts {
+	return prometheus.GaugeOpts{
+		Namespace:   n.name,
+		Subsystem:   n.subsystem,
+		Name:        makeName(name, unit),
+		Help:        help,
+		ConstLabels: prometheus.Labels(n.labels),
+	}
+}
+
+func (n *Namespace) Describe(ch chan<- *prometheus.Desc) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
+	for _, metric := range n.metrics {
+		metric.Describe(ch)
+	}
+}
+
+func (n *Namespace) Collect(ch chan<- prometheus.Metric) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
+	for _, metric := range n.metrics {
+		metric.Collect(ch)
+	}
+}
+
+func (n *Namespace) Add(collector prometheus.Collector) {
+	n.mu.Lock()
+	n.metrics = append(n.metrics, collector)
+	n.mu.Unlock()
+}
+
+func (n *Namespace) NewDesc(name, help string, unit Unit, labels ...string) *prometheus.Desc {
+	name = makeName(name, unit)
+	namespace := n.name
+	if n.subsystem != "" {
+		namespace = fmt.Sprintf("%s_%s", namespace, n.subsystem)
+	}
+	name = fmt.Sprintf("%s_%s", namespace, name)
+	return prometheus.NewDesc(name, help, labels, prometheus.Labels(n.labels))
+}
+
+// mergeLabels merges two or more labels objects into a single map, favoring
+// the later labels.
+func mergeLabels(lbs ...Labels) Labels {
+	merged := make(Labels)
+
+	for _, target := range lbs {
+		for k, v := range target {
+			merged[k] = v
+		}
+	}
+
+	return merged
+}
+
+func makeName(name string, unit Unit) string {
+	if unit == "" {
+		return name
+	}
+
+	return fmt.Sprintf("%s_%s", name, unit)
+}
+
+func (n *Namespace) NewDefaultHttpMetrics(handlerName string) []*HTTPMetric {
+	return n.NewHttpMetricsWithOpts(handlerName, HTTPHandlerOpts{
+		DurationBuckets:     defaultDurationBuckets,
+		RequestSizeBuckets:  defaultResponseSizeBuckets,
+		ResponseSizeBuckets: defaultResponseSizeBuckets,
+	})
+}
+
+func (n *Namespace) NewHttpMetrics(handlerName string, durationBuckets, requestSizeBuckets, responseSizeBuckets []float64) []*HTTPMetric {
+	return n.NewHttpMetricsWithOpts(handlerName, HTTPHandlerOpts{
+		DurationBuckets:     durationBuckets,
+		RequestSizeBuckets:  requestSizeBuckets,
+		ResponseSizeBuckets: responseSizeBuckets,
+	})
+}
+
+func (n *Namespace) NewHttpMetricsWithOpts(handlerName string, opts HTTPHandlerOpts) []*HTTPMetric {
+	var httpMetrics []*HTTPMetric
+	inFlightMetric := n.NewInFlightGaugeMetric(handlerName)
+	requestTotalMetric := n.NewRequestTotalMetric(handlerName)
+	requestDurationMetric := n.NewRequestDurationMetric(handlerName, opts.DurationBuckets)
+	requestSizeMetric := n.NewRequestSizeMetric(handlerName, opts.RequestSizeBuckets)
+	responseSizeMetric := n.NewResponseSizeMetric(handlerName, opts.ResponseSizeBuckets)
+	httpMetrics = append(httpMetrics, inFlightMetric, requestDurationMetric, requestTotalMetric, requestSizeMetric, responseSizeMetric)
+	return httpMetrics
+}
+
+func (n *Namespace) NewInFlightGaugeMetric(handlerName string) *HTTPMetric {
+	labels := prometheus.Labels(n.labels)
+	labels["handler"] = handlerName
+	metric := prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace:   n.name,
+		Subsystem:   n.subsystem,
+		Name:        "in_flight_requests",
+		Help:        "The in-flight HTTP requests",
+		ConstLabels: prometheus.Labels(labels),
+	})
+	httpMetric := &HTTPMetric{
+		Collector:   metric,
+		handlerType: InstrumentHandlerInFlight,
+	}
+	n.Add(httpMetric)
+	return httpMetric
+}
+
+func (n *Namespace) NewRequestTotalMetric(handlerName string) *HTTPMetric {
+	labels := prometheus.Labels(n.labels)
+	labels["handler"] = handlerName
+	metric := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace:   n.name,
+			Subsystem:   n.subsystem,
+			Name:        "requests_total",
+			Help:        "Total number of HTTP requests made.",
+			ConstLabels: prometheus.Labels(labels),
+		},
+		[]string{"code", "method"},
+	)
+	httpMetric := &HTTPMetric{
+		Collector:   metric,
+		handlerType: InstrumentHandlerCounter,
+	}
+	n.Add(httpMetric)
+	return httpMetric
+}
+func (n *Namespace) NewRequestDurationMetric(handlerName string, buckets []float64) *HTTPMetric {
+	if len(buckets) == 0 {
+		panic("DurationBuckets must be provided")
+	}
+	labels := prometheus.Labels(n.labels)
+	labels["handler"] = handlerName
+	opts := prometheus.HistogramOpts{
+		Namespace:   n.name,
+		Subsystem:   n.subsystem,
+		Name:        "request_duration_seconds",
+		Help:        "The HTTP request latencies in seconds.",
+		Buckets:     buckets,
+		ConstLabels: prometheus.Labels(labels),
+	}
+	metric := prometheus.NewHistogramVec(opts, []string{"method"})
+	httpMetric := &HTTPMetric{
+		Collector:   metric,
+		handlerType: InstrumentHandlerDuration,
+	}
+	n.Add(httpMetric)
+	return httpMetric
+}
+
+func (n *Namespace) NewRequestSizeMetric(handlerName string, buckets []float64) *HTTPMetric {
+	if len(buckets) == 0 {
+		panic("RequestSizeBuckets must be provided")
+	}
+	labels := prometheus.Labels(n.labels)
+	labels["handler"] = handlerName
+	opts := prometheus.HistogramOpts{
+		Namespace:   n.name,
+		Subsystem:   n.subsystem,
+		Name:        "request_size_bytes",
+		Help:        "The HTTP request sizes in bytes.",
+		Buckets:     buckets,
+		ConstLabels: prometheus.Labels(labels),
+	}
+	metric := prometheus.NewHistogramVec(opts, []string{})
+	httpMetric := &HTTPMetric{
+		Collector:   metric,
+		handlerType: InstrumentHandlerRequestSize,
+	}
+	n.Add(httpMetric)
+	return httpMetric
+}
+
+func (n *Namespace) NewResponseSizeMetric(handlerName string, buckets []float64) *HTTPMetric {
+	if len(buckets) == 0 {
+		panic("ResponseSizeBuckets must be provided")
+	}
+	labels := prometheus.Labels(n.labels)
+	labels["handler"] = handlerName
+	opts := prometheus.HistogramOpts{
+		Namespace:   n.name,
+		Subsystem:   n.subsystem,
+		Name:        "response_size_bytes",
+		Help:        "The HTTP response sizes in bytes.",
+		Buckets:     buckets,
+		ConstLabels: prometheus.Labels(labels),
+	}
+	metrics := prometheus.NewHistogramVec(opts, []string{})
+	httpMetric := &HTTPMetric{
+		Collector:   metrics,
+		handlerType: InstrumentHandlerResponseSize,
+	}
+	n.Add(httpMetric)
+	return httpMetric
+}