[VOL-1349] EPON ONU adapter (package B)

Change-Id: I609ba349c429bc7e87c74b66bb1121841f9caef6
diff --git a/vendor/github.com/armon/go-metrics/metrics.go b/vendor/github.com/armon/go-metrics/metrics.go
new file mode 100644
index 0000000..4920d68
--- /dev/null
+++ b/vendor/github.com/armon/go-metrics/metrics.go
@@ -0,0 +1,278 @@
+package metrics
+
+import (
+	"runtime"
+	"strings"
+	"time"
+
+	"github.com/hashicorp/go-immutable-radix"
+)
+
+type Label struct {
+	Name  string
+	Value string
+}
+
+func (m *Metrics) SetGauge(key []string, val float32) {
+	m.SetGaugeWithLabels(key, val, nil)
+}
+
+func (m *Metrics) SetGaugeWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" {
+		if m.EnableHostnameLabel {
+			labels = append(labels, Label{"host", m.HostName})
+		} else if m.EnableHostname {
+			key = insert(0, m.HostName, key)
+		}
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "gauge", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.SetGaugeWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) EmitKey(key []string, val float32) {
+	if m.EnableTypePrefix {
+		key = insert(0, "kv", key)
+	}
+	if m.ServiceName != "" {
+		key = insert(0, m.ServiceName, key)
+	}
+	allowed, _ := m.allowMetric(key, nil)
+	if !allowed {
+		return
+	}
+	m.sink.EmitKey(key, val)
+}
+
+func (m *Metrics) IncrCounter(key []string, val float32) {
+	m.IncrCounterWithLabels(key, val, nil)
+}
+
+func (m *Metrics) IncrCounterWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "counter", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.IncrCounterWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) AddSample(key []string, val float32) {
+	m.AddSampleWithLabels(key, val, nil)
+}
+
+func (m *Metrics) AddSampleWithLabels(key []string, val float32, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "sample", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	m.sink.AddSampleWithLabels(key, val, labelsFiltered)
+}
+
+func (m *Metrics) MeasureSince(key []string, start time.Time) {
+	m.MeasureSinceWithLabels(key, start, nil)
+}
+
+func (m *Metrics) MeasureSinceWithLabels(key []string, start time.Time, labels []Label) {
+	if m.HostName != "" && m.EnableHostnameLabel {
+		labels = append(labels, Label{"host", m.HostName})
+	}
+	if m.EnableTypePrefix {
+		key = insert(0, "timer", key)
+	}
+	if m.ServiceName != "" {
+		if m.EnableServiceLabel {
+			labels = append(labels, Label{"service", m.ServiceName})
+		} else {
+			key = insert(0, m.ServiceName, key)
+		}
+	}
+	allowed, labelsFiltered := m.allowMetric(key, labels)
+	if !allowed {
+		return
+	}
+	now := time.Now()
+	elapsed := now.Sub(start)
+	msec := float32(elapsed.Nanoseconds()) / float32(m.TimerGranularity)
+	m.sink.AddSampleWithLabels(key, msec, labelsFiltered)
+}
+
+// UpdateFilter overwrites the existing filter with the given rules.
+func (m *Metrics) UpdateFilter(allow, block []string) {
+	m.UpdateFilterAndLabels(allow, block, m.AllowedLabels, m.BlockedLabels)
+}
+
+// UpdateFilterAndLabels overwrites the existing filter with the given rules.
+func (m *Metrics) UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
+	m.filterLock.Lock()
+	defer m.filterLock.Unlock()
+
+	m.AllowedPrefixes = allow
+	m.BlockedPrefixes = block
+
+	if allowedLabels == nil {
+		// Having a white list means we take only elements from it
+		m.allowedLabels = nil
+	} else {
+		m.allowedLabels = make(map[string]bool)
+		for _, v := range allowedLabels {
+			m.allowedLabels[v] = true
+		}
+	}
+	m.blockedLabels = make(map[string]bool)
+	for _, v := range blockedLabels {
+		m.blockedLabels[v] = true
+	}
+	m.AllowedLabels = allowedLabels
+	m.BlockedLabels = blockedLabels
+
+	m.filter = iradix.New()
+	for _, prefix := range m.AllowedPrefixes {
+		m.filter, _, _ = m.filter.Insert([]byte(prefix), true)
+	}
+	for _, prefix := range m.BlockedPrefixes {
+		m.filter, _, _ = m.filter.Insert([]byte(prefix), false)
+	}
+}
+
+// labelIsAllowed return true if a should be included in metric
+// the caller should lock m.filterLock while calling this method
+func (m *Metrics) labelIsAllowed(label *Label) bool {
+	labelName := (*label).Name
+	if m.blockedLabels != nil {
+		_, ok := m.blockedLabels[labelName]
+		if ok {
+			// If present, let's remove this label
+			return false
+		}
+	}
+	if m.allowedLabels != nil {
+		_, ok := m.allowedLabels[labelName]
+		return ok
+	}
+	// Allow by default
+	return true
+}
+
+// filterLabels return only allowed labels
+// the caller should lock m.filterLock while calling this method
+func (m *Metrics) filterLabels(labels []Label) []Label {
+	if labels == nil {
+		return nil
+	}
+	toReturn := []Label{}
+	for _, label := range labels {
+		if m.labelIsAllowed(&label) {
+			toReturn = append(toReturn, label)
+		}
+	}
+	return toReturn
+}
+
+// Returns whether the metric should be allowed based on configured prefix filters
+// Also return the applicable labels
+func (m *Metrics) allowMetric(key []string, labels []Label) (bool, []Label) {
+	m.filterLock.RLock()
+	defer m.filterLock.RUnlock()
+
+	if m.filter == nil || m.filter.Len() == 0 {
+		return m.Config.FilterDefault, m.filterLabels(labels)
+	}
+
+	_, allowed, ok := m.filter.Root().LongestPrefix([]byte(strings.Join(key, ".")))
+	if !ok {
+		return m.Config.FilterDefault, m.filterLabels(labels)
+	}
+
+	return allowed.(bool), m.filterLabels(labels)
+}
+
+// Periodically collects runtime stats to publish
+func (m *Metrics) collectStats() {
+	for {
+		time.Sleep(m.ProfileInterval)
+		m.emitRuntimeStats()
+	}
+}
+
+// Emits various runtime statsitics
+func (m *Metrics) emitRuntimeStats() {
+	// Export number of Goroutines
+	numRoutines := runtime.NumGoroutine()
+	m.SetGauge([]string{"runtime", "num_goroutines"}, float32(numRoutines))
+
+	// Export memory stats
+	var stats runtime.MemStats
+	runtime.ReadMemStats(&stats)
+	m.SetGauge([]string{"runtime", "alloc_bytes"}, float32(stats.Alloc))
+	m.SetGauge([]string{"runtime", "sys_bytes"}, float32(stats.Sys))
+	m.SetGauge([]string{"runtime", "malloc_count"}, float32(stats.Mallocs))
+	m.SetGauge([]string{"runtime", "free_count"}, float32(stats.Frees))
+	m.SetGauge([]string{"runtime", "heap_objects"}, float32(stats.HeapObjects))
+	m.SetGauge([]string{"runtime", "total_gc_pause_ns"}, float32(stats.PauseTotalNs))
+	m.SetGauge([]string{"runtime", "total_gc_runs"}, float32(stats.NumGC))
+
+	// Export info about the last few GC runs
+	num := stats.NumGC
+
+	// Handle wrap around
+	if num < m.lastNumGC {
+		m.lastNumGC = 0
+	}
+
+	// Ensure we don't scan more than 256
+	if num-m.lastNumGC >= 256 {
+		m.lastNumGC = num - 255
+	}
+
+	for i := m.lastNumGC; i < num; i++ {
+		pause := stats.PauseNs[i%256]
+		m.AddSample([]string{"runtime", "gc_pause_ns"}, float32(pause))
+	}
+	m.lastNumGC = num
+}
+
+// Inserts a string value at an index into the slice
+func insert(i int, v string, s []string) []string {
+	s = append(s, "")
+	copy(s[i+1:], s[i:])
+	s[i] = v
+	return s
+}