metric: new pkg refactored from log for #90

pkg/log/metrics.go

@@ -1,62 +0,0 @@
-package log
-
-import (
-	"container/list"
-	"expvar"
-	"strings"
-	"time"
-)
-
-// TickerFunc is the type of metrics function accepted by AddTickerFunc
-type TickerFunc func()
-
-var tickerFuncChan = make(chan TickerFunc)
-
-func init() {
-	go metricsTicker()
-}
-
-// AddTickerFunc adds a new function callback to the list of metrics TickerFuncs that get
-// called each minute.
-func AddTickerFunc(f TickerFunc) {
-	tickerFuncChan <- f
-}
-
-// PushMetric adds the metric to the end of the list and returns a comma separated string of the
-// previous 61 entries.  We return 61 instead of 60 (an hour) because the chart on the client
-// tracks deltas between these values - there is nothing to compare the first value against.
-func PushMetric(history *list.List, ev expvar.Var) string {
-	history.PushBack(ev.String())
-	if history.Len() > 61 {
-		history.Remove(history.Front())
-	}
-	return joinStringList(history)
-}
-
-// joinStringList joins a List containing strings by commas
-func joinStringList(listOfStrings *list.List) string {
-	if listOfStrings.Len() == 0 {
-		return ""
-	}
-	s := make([]string, 0, listOfStrings.Len())
-	for e := listOfStrings.Front(); e != nil; e = e.Next() {
-		s = append(s, e.Value.(string))
-	}
-	return strings.Join(s, ",")
-}
-
-func metricsTicker() {
-	funcs := make([]TickerFunc, 0)
-	ticker := time.NewTicker(time.Minute)
-
-	for {
-		select {
-		case <-ticker.C:
-			for _, f := range funcs {
-				f()
-			}
-		case f := <-tickerFuncChan:
-			funcs = append(funcs, f)
-		}
-	}
-}