[VOL-1386] This commit add "dep" as the package management tool
for voltha-go.
Change-Id: I52bc4911dd00a441756ec7c30f46d45091f3f90e
diff --git a/vendor/github.com/armon/go-metrics/inmem.go b/vendor/github.com/armon/go-metrics/inmem.go
new file mode 100644
index 0000000..83fb6bb
--- /dev/null
+++ b/vendor/github.com/armon/go-metrics/inmem.go
@@ -0,0 +1,247 @@
+package metrics
+
+import (
+ "fmt"
+ "math"
+ "strings"
+ "sync"
+ "time"
+)
+
+// InmemSink provides a MetricSink that does in-memory aggregation
+// without sending metrics over a network. It can be embedded within
+// an application to provide profiling information.
+type InmemSink struct {
+ // How long is each aggregation interval
+ interval time.Duration
+
+ // Retain controls how many metrics interval we keep
+ retain time.Duration
+
+ // maxIntervals is the maximum length of intervals.
+ // It is retain / interval.
+ maxIntervals int
+
+ // intervals is a slice of the retained intervals
+ intervals []*IntervalMetrics
+ intervalLock sync.RWMutex
+
+ rateDenom float64
+}
+
+// IntervalMetrics stores the aggregated metrics
+// for a specific interval
+type IntervalMetrics struct {
+ sync.RWMutex
+
+ // The start time of the interval
+ Interval time.Time
+
+ // Gauges maps the key to the last set value
+ Gauges map[string]float32
+
+ // Points maps the string to the list of emitted values
+ // from EmitKey
+ Points map[string][]float32
+
+ // Counters maps the string key to a sum of the counter
+ // values
+ Counters map[string]*AggregateSample
+
+ // Samples maps the key to an AggregateSample,
+ // which has the rolled up view of a sample
+ Samples map[string]*AggregateSample
+}
+
+// NewIntervalMetrics creates a new IntervalMetrics for a given interval
+func NewIntervalMetrics(intv time.Time) *IntervalMetrics {
+ return &IntervalMetrics{
+ Interval: intv,
+ Gauges: make(map[string]float32),
+ Points: make(map[string][]float32),
+ Counters: make(map[string]*AggregateSample),
+ Samples: make(map[string]*AggregateSample),
+ }
+}
+
+// AggregateSample is used to hold aggregate metrics
+// about a sample
+type AggregateSample struct {
+ Count int // The count of emitted pairs
+ Rate float64 // The count of emitted pairs per time unit (usually 1 second)
+ Sum float64 // The sum of values
+ SumSq float64 // The sum of squared values
+ Min float64 // Minimum value
+ Max float64 // Maximum value
+ LastUpdated time.Time // When value was last updated
+}
+
+// Computes a Stddev of the values
+func (a *AggregateSample) Stddev() float64 {
+ num := (float64(a.Count) * a.SumSq) - math.Pow(a.Sum, 2)
+ div := float64(a.Count * (a.Count - 1))
+ if div == 0 {
+ return 0
+ }
+ return math.Sqrt(num / div)
+}
+
+// Computes a mean of the values
+func (a *AggregateSample) Mean() float64 {
+ if a.Count == 0 {
+ return 0
+ }
+ return a.Sum / float64(a.Count)
+}
+
+// Ingest is used to update a sample
+func (a *AggregateSample) Ingest(v float64, rateDenom float64) {
+ a.Count++
+ a.Sum += v
+ a.SumSq += (v * v)
+ if v < a.Min || a.Count == 1 {
+ a.Min = v
+ }
+ if v > a.Max || a.Count == 1 {
+ a.Max = v
+ }
+ a.Rate = float64(a.Count)/rateDenom
+ a.LastUpdated = time.Now()
+}
+
+func (a *AggregateSample) String() string {
+ if a.Count == 0 {
+ return "Count: 0"
+ } else if a.Stddev() == 0 {
+ return fmt.Sprintf("Count: %d Sum: %0.3f LastUpdated: %s", a.Count, a.Sum, a.LastUpdated)
+ } else {
+ return fmt.Sprintf("Count: %d Min: %0.3f Mean: %0.3f Max: %0.3f Stddev: %0.3f Sum: %0.3f LastUpdated: %s",
+ a.Count, a.Min, a.Mean(), a.Max, a.Stddev(), a.Sum, a.LastUpdated)
+ }
+}
+
+// NewInmemSink is used to construct a new in-memory sink.
+// Uses an aggregation interval and maximum retention period.
+func NewInmemSink(interval, retain time.Duration) *InmemSink {
+ rateTimeUnit := time.Second
+ i := &InmemSink{
+ interval: interval,
+ retain: retain,
+ maxIntervals: int(retain / interval),
+ rateDenom: float64(interval.Nanoseconds()) / float64(rateTimeUnit.Nanoseconds()),
+ }
+ i.intervals = make([]*IntervalMetrics, 0, i.maxIntervals)
+ return i
+}
+
+func (i *InmemSink) SetGauge(key []string, val float32) {
+ k := i.flattenKey(key)
+ intv := i.getInterval()
+
+ intv.Lock()
+ defer intv.Unlock()
+ intv.Gauges[k] = val
+}
+
+func (i *InmemSink) EmitKey(key []string, val float32) {
+ k := i.flattenKey(key)
+ intv := i.getInterval()
+
+ intv.Lock()
+ defer intv.Unlock()
+ vals := intv.Points[k]
+ intv.Points[k] = append(vals, val)
+}
+
+func (i *InmemSink) IncrCounter(key []string, val float32) {
+ k := i.flattenKey(key)
+ intv := i.getInterval()
+
+ intv.Lock()
+ defer intv.Unlock()
+
+ agg := intv.Counters[k]
+ if agg == nil {
+ agg = &AggregateSample{}
+ intv.Counters[k] = agg
+ }
+ agg.Ingest(float64(val), i.rateDenom)
+}
+
+func (i *InmemSink) AddSample(key []string, val float32) {
+ k := i.flattenKey(key)
+ intv := i.getInterval()
+
+ intv.Lock()
+ defer intv.Unlock()
+
+ agg := intv.Samples[k]
+ if agg == nil {
+ agg = &AggregateSample{}
+ intv.Samples[k] = agg
+ }
+ agg.Ingest(float64(val), i.rateDenom)
+}
+
+// Data is used to retrieve all the aggregated metrics
+// Intervals may be in use, and a read lock should be acquired
+func (i *InmemSink) Data() []*IntervalMetrics {
+ // Get the current interval, forces creation
+ i.getInterval()
+
+ i.intervalLock.RLock()
+ defer i.intervalLock.RUnlock()
+
+ intervals := make([]*IntervalMetrics, len(i.intervals))
+ copy(intervals, i.intervals)
+ return intervals
+}
+
+func (i *InmemSink) getExistingInterval(intv time.Time) *IntervalMetrics {
+ i.intervalLock.RLock()
+ defer i.intervalLock.RUnlock()
+
+ n := len(i.intervals)
+ if n > 0 && i.intervals[n-1].Interval == intv {
+ return i.intervals[n-1]
+ }
+ return nil
+}
+
+func (i *InmemSink) createInterval(intv time.Time) *IntervalMetrics {
+ i.intervalLock.Lock()
+ defer i.intervalLock.Unlock()
+
+ // Check for an existing interval
+ n := len(i.intervals)
+ if n > 0 && i.intervals[n-1].Interval == intv {
+ return i.intervals[n-1]
+ }
+
+ // Add the current interval
+ current := NewIntervalMetrics(intv)
+ i.intervals = append(i.intervals, current)
+ n++
+
+ // Truncate the intervals if they are too long
+ if n >= i.maxIntervals {
+ copy(i.intervals[0:], i.intervals[n-i.maxIntervals:])
+ i.intervals = i.intervals[:i.maxIntervals]
+ }
+ return current
+}
+
+// getInterval returns the current interval to write to
+func (i *InmemSink) getInterval() *IntervalMetrics {
+ intv := time.Now().Truncate(i.interval)
+ if m := i.getExistingInterval(intv); m != nil {
+ return m
+ }
+ return i.createInterval(intv)
+}
+
+// Flattens the key for formatting, removes spaces
+func (i *InmemSink) flattenKey(parts []string) string {
+ joined := strings.Join(parts, ".")
+ return strings.Replace(joined, " ", "_", -1)
+}