VOL-2496 Add "event listen" command to voltctl
Change-Id: I8f1fb34b55f56c8125142ac289e2f19fc170d804
diff --git a/vendor/github.com/rcrowley/go-metrics/registry.go b/vendor/github.com/rcrowley/go-metrics/registry.go
new file mode 100644
index 0000000..b3bab64
--- /dev/null
+++ b/vendor/github.com/rcrowley/go-metrics/registry.go
@@ -0,0 +1,363 @@
+package metrics
+
+import (
+ "fmt"
+ "reflect"
+ "strings"
+ "sync"
+)
+
+// DuplicateMetric is the error returned by Registry.Register when a metric
+// already exists. If you mean to Register that metric you must first
+// Unregister the existing metric.
+type DuplicateMetric string
+
+func (err DuplicateMetric) Error() string {
+ return fmt.Sprintf("duplicate metric: %s", string(err))
+}
+
+// A Registry holds references to a set of metrics by name and can iterate
+// over them, calling callback functions provided by the user.
+//
+// This is an interface so as to encourage other structs to implement
+// the Registry API as appropriate.
+type Registry interface {
+
+ // Call the given function for each registered metric.
+ Each(func(string, interface{}))
+
+ // Get the metric by the given name or nil if none is registered.
+ Get(string) interface{}
+
+ // GetAll metrics in the Registry.
+ GetAll() map[string]map[string]interface{}
+
+ // Gets an existing metric or registers the given one.
+ // The interface can be the metric to register if not found in registry,
+ // or a function returning the metric for lazy instantiation.
+ GetOrRegister(string, interface{}) interface{}
+
+ // Register the given metric under the given name.
+ Register(string, interface{}) error
+
+ // Run all registered healthchecks.
+ RunHealthchecks()
+
+ // Unregister the metric with the given name.
+ Unregister(string)
+
+ // Unregister all metrics. (Mostly for testing.)
+ UnregisterAll()
+}
+
+// The standard implementation of a Registry is a mutex-protected map
+// of names to metrics.
+type StandardRegistry struct {
+ metrics map[string]interface{}
+ mutex sync.RWMutex
+}
+
+// Create a new registry.
+func NewRegistry() Registry {
+ return &StandardRegistry{metrics: make(map[string]interface{})}
+}
+
+// Call the given function for each registered metric.
+func (r *StandardRegistry) Each(f func(string, interface{})) {
+ for name, i := range r.registered() {
+ f(name, i)
+ }
+}
+
+// Get the metric by the given name or nil if none is registered.
+func (r *StandardRegistry) Get(name string) interface{} {
+ r.mutex.RLock()
+ defer r.mutex.RUnlock()
+ return r.metrics[name]
+}
+
+// Gets an existing metric or creates and registers a new one. Threadsafe
+// alternative to calling Get and Register on failure.
+// The interface can be the metric to register if not found in registry,
+// or a function returning the metric for lazy instantiation.
+func (r *StandardRegistry) GetOrRegister(name string, i interface{}) interface{} {
+ // access the read lock first which should be re-entrant
+ r.mutex.RLock()
+ metric, ok := r.metrics[name]
+ r.mutex.RUnlock()
+ if ok {
+ return metric
+ }
+
+ // only take the write lock if we'll be modifying the metrics map
+ r.mutex.Lock()
+ defer r.mutex.Unlock()
+ if metric, ok := r.metrics[name]; ok {
+ return metric
+ }
+ if v := reflect.ValueOf(i); v.Kind() == reflect.Func {
+ i = v.Call(nil)[0].Interface()
+ }
+ r.register(name, i)
+ return i
+}
+
+// Register the given metric under the given name. Returns a DuplicateMetric
+// if a metric by the given name is already registered.
+func (r *StandardRegistry) Register(name string, i interface{}) error {
+ r.mutex.Lock()
+ defer r.mutex.Unlock()
+ return r.register(name, i)
+}
+
+// Run all registered healthchecks.
+func (r *StandardRegistry) RunHealthchecks() {
+ r.mutex.RLock()
+ defer r.mutex.RUnlock()
+ for _, i := range r.metrics {
+ if h, ok := i.(Healthcheck); ok {
+ h.Check()
+ }
+ }
+}
+
+// GetAll metrics in the Registry
+func (r *StandardRegistry) GetAll() map[string]map[string]interface{} {
+ data := make(map[string]map[string]interface{})
+ r.Each(func(name string, i interface{}) {
+ values := make(map[string]interface{})
+ switch metric := i.(type) {
+ case Counter:
+ values["count"] = metric.Count()
+ case Gauge:
+ values["value"] = metric.Value()
+ case GaugeFloat64:
+ values["value"] = metric.Value()
+ case Healthcheck:
+ values["error"] = nil
+ metric.Check()
+ if err := metric.Error(); nil != err {
+ values["error"] = metric.Error().Error()
+ }
+ case Histogram:
+ h := metric.Snapshot()
+ ps := h.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999})
+ values["count"] = h.Count()
+ values["min"] = h.Min()
+ values["max"] = h.Max()
+ values["mean"] = h.Mean()
+ values["stddev"] = h.StdDev()
+ values["median"] = ps[0]
+ values["75%"] = ps[1]
+ values["95%"] = ps[2]
+ values["99%"] = ps[3]
+ values["99.9%"] = ps[4]
+ case Meter:
+ m := metric.Snapshot()
+ values["count"] = m.Count()
+ values["1m.rate"] = m.Rate1()
+ values["5m.rate"] = m.Rate5()
+ values["15m.rate"] = m.Rate15()
+ values["mean.rate"] = m.RateMean()
+ case Timer:
+ t := metric.Snapshot()
+ ps := t.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999})
+ values["count"] = t.Count()
+ values["min"] = t.Min()
+ values["max"] = t.Max()
+ values["mean"] = t.Mean()
+ values["stddev"] = t.StdDev()
+ values["median"] = ps[0]
+ values["75%"] = ps[1]
+ values["95%"] = ps[2]
+ values["99%"] = ps[3]
+ values["99.9%"] = ps[4]
+ values["1m.rate"] = t.Rate1()
+ values["5m.rate"] = t.Rate5()
+ values["15m.rate"] = t.Rate15()
+ values["mean.rate"] = t.RateMean()
+ }
+ data[name] = values
+ })
+ return data
+}
+
+// Unregister the metric with the given name.
+func (r *StandardRegistry) Unregister(name string) {
+ r.mutex.Lock()
+ defer r.mutex.Unlock()
+ r.stop(name)
+ delete(r.metrics, name)
+}
+
+// Unregister all metrics. (Mostly for testing.)
+func (r *StandardRegistry) UnregisterAll() {
+ r.mutex.Lock()
+ defer r.mutex.Unlock()
+ for name, _ := range r.metrics {
+ r.stop(name)
+ delete(r.metrics, name)
+ }
+}
+
+func (r *StandardRegistry) register(name string, i interface{}) error {
+ if _, ok := r.metrics[name]; ok {
+ return DuplicateMetric(name)
+ }
+ switch i.(type) {
+ case Counter, Gauge, GaugeFloat64, Healthcheck, Histogram, Meter, Timer:
+ r.metrics[name] = i
+ }
+ return nil
+}
+
+func (r *StandardRegistry) registered() map[string]interface{} {
+ r.mutex.Lock()
+ defer r.mutex.Unlock()
+ metrics := make(map[string]interface{}, len(r.metrics))
+ for name, i := range r.metrics {
+ metrics[name] = i
+ }
+ return metrics
+}
+
+func (r *StandardRegistry) stop(name string) {
+ if i, ok := r.metrics[name]; ok {
+ if s, ok := i.(Stoppable); ok {
+ s.Stop()
+ }
+ }
+}
+
+// Stoppable defines the metrics which has to be stopped.
+type Stoppable interface {
+ Stop()
+}
+
+type PrefixedRegistry struct {
+ underlying Registry
+ prefix string
+}
+
+func NewPrefixedRegistry(prefix string) Registry {
+ return &PrefixedRegistry{
+ underlying: NewRegistry(),
+ prefix: prefix,
+ }
+}
+
+func NewPrefixedChildRegistry(parent Registry, prefix string) Registry {
+ return &PrefixedRegistry{
+ underlying: parent,
+ prefix: prefix,
+ }
+}
+
+// Call the given function for each registered metric.
+func (r *PrefixedRegistry) Each(fn func(string, interface{})) {
+ wrappedFn := func(prefix string) func(string, interface{}) {
+ return func(name string, iface interface{}) {
+ if strings.HasPrefix(name, prefix) {
+ fn(name, iface)
+ } else {
+ return
+ }
+ }
+ }
+
+ baseRegistry, prefix := findPrefix(r, "")
+ baseRegistry.Each(wrappedFn(prefix))
+}
+
+func findPrefix(registry Registry, prefix string) (Registry, string) {
+ switch r := registry.(type) {
+ case *PrefixedRegistry:
+ return findPrefix(r.underlying, r.prefix+prefix)
+ case *StandardRegistry:
+ return r, prefix
+ }
+ return nil, ""
+}
+
+// Get the metric by the given name or nil if none is registered.
+func (r *PrefixedRegistry) Get(name string) interface{} {
+ realName := r.prefix + name
+ return r.underlying.Get(realName)
+}
+
+// Gets an existing metric or registers the given one.
+// The interface can be the metric to register if not found in registry,
+// or a function returning the metric for lazy instantiation.
+func (r *PrefixedRegistry) GetOrRegister(name string, metric interface{}) interface{} {
+ realName := r.prefix + name
+ return r.underlying.GetOrRegister(realName, metric)
+}
+
+// Register the given metric under the given name. The name will be prefixed.
+func (r *PrefixedRegistry) Register(name string, metric interface{}) error {
+ realName := r.prefix + name
+ return r.underlying.Register(realName, metric)
+}
+
+// Run all registered healthchecks.
+func (r *PrefixedRegistry) RunHealthchecks() {
+ r.underlying.RunHealthchecks()
+}
+
+// GetAll metrics in the Registry
+func (r *PrefixedRegistry) GetAll() map[string]map[string]interface{} {
+ return r.underlying.GetAll()
+}
+
+// Unregister the metric with the given name. The name will be prefixed.
+func (r *PrefixedRegistry) Unregister(name string) {
+ realName := r.prefix + name
+ r.underlying.Unregister(realName)
+}
+
+// Unregister all metrics. (Mostly for testing.)
+func (r *PrefixedRegistry) UnregisterAll() {
+ r.underlying.UnregisterAll()
+}
+
+var DefaultRegistry Registry = NewRegistry()
+
+// Call the given function for each registered metric.
+func Each(f func(string, interface{})) {
+ DefaultRegistry.Each(f)
+}
+
+// Get the metric by the given name or nil if none is registered.
+func Get(name string) interface{} {
+ return DefaultRegistry.Get(name)
+}
+
+// Gets an existing metric or creates and registers a new one. Threadsafe
+// alternative to calling Get and Register on failure.
+func GetOrRegister(name string, i interface{}) interface{} {
+ return DefaultRegistry.GetOrRegister(name, i)
+}
+
+// Register the given metric under the given name. Returns a DuplicateMetric
+// if a metric by the given name is already registered.
+func Register(name string, i interface{}) error {
+ return DefaultRegistry.Register(name, i)
+}
+
+// Register the given metric under the given name. Panics if a metric by the
+// given name is already registered.
+func MustRegister(name string, i interface{}) {
+ if err := Register(name, i); err != nil {
+ panic(err)
+ }
+}
+
+// Run all registered healthchecks.
+func RunHealthchecks() {
+ DefaultRegistry.RunHealthchecks()
+}
+
+// Unregister the metric with the given name.
+func Unregister(name string) {
+ DefaultRegistry.Unregister(name)
+}