Address review comments.

main.go

@@ -8,24 +8,25 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"log"
 	"net"
 	"net/http"
 	"strconv"
 	"strings"
-	"sync"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/exp"
 )
 
-var listeningAddress = flag.String("listeningAddress", ":8080", "The address on which to expose generated Prometheus metrics.")
-var statsdListeningAddress = flag.String("statsdListeningAddress", ":8126", "The UDP address on which to receive statsd metric lines.")
+var (
+	listeningAddress       = flag.String("listeningAddress", ":8080", "The address on which to expose generated Prometheus metrics.")
+	statsdListeningAddress = flag.String("statsdListeningAddress", ":8126", "The UDP address on which to receive statsd metric lines.")
+	summaryFlushInterval   = flag.Duration("summaryFlushInterval", time.Hour, "How frequently to reset all summary metrics.")
+)
 
 type CounterContainer struct {
-	sync.RWMutex
-
 	Elements map[string]prometheus.Counter
 }
 
@@ -36,9 +37,6 @@ func NewCounterContainer() *CounterContainer {
 }
 
 func (c *CounterContainer) Get(metricName string) prometheus.Counter {
-	c.Lock()
-	defer c.Unlock()
-
 	counter, ok := c.Elements[metricName]
 	if !ok {
 		counter = prometheus.NewCounter()
@@ -49,8 +47,6 @@ func (c *CounterContainer) Get(metricName string) prometheus.Counter {
 }
 
 type GaugeContainer struct {
-	sync.RWMutex
-
 	Elements map[string]prometheus.Gauge
 }
 
@@ -61,9 +57,6 @@ func NewGaugeContainer() *GaugeContainer {
 }
 
 func (c *GaugeContainer) Get(metricName string) prometheus.Gauge {
-	c.Lock()
-	defer c.Unlock()
-
 	gauge, ok := c.Elements[metricName]
 	if !ok {
 		gauge = prometheus.NewGauge()
@@ -74,11 +67,7 @@ func (c *GaugeContainer) Get(metricName string) prometheus.Gauge {
 }
 
 type SummaryContainer struct {
-	sync.RWMutex
-
 	Elements map[string]prometheus.Histogram
-
-	ResetInterval time.Duration
 }
 
 func NewSummaryContainer() *SummaryContainer {
@@ -88,9 +77,6 @@ func NewSummaryContainer() *SummaryContainer {
 }
 
 func (c *SummaryContainer) Get(metricName string) prometheus.Histogram {
-	c.Lock()
-	defer c.Unlock()
-
 	summary, ok := c.Elements[metricName]
 	if !ok {
 		summary = prometheus.NewDefaultHistogram()
@@ -100,6 +86,12 @@ func (c *SummaryContainer) Get(metricName string) prometheus.Histogram {
 	return summary
 }
 
+func (c *SummaryContainer) Flush() {
+	for _, summary := range c.Elements {
+		summary.ResetAll()
+	}
+}
+
 type Event interface {
 	MetricName() string
 	Value() float64
@@ -179,6 +171,30 @@ type StatsDListener struct {
 	conn *net.UDPConn
 }
 
+func buildEvent(statType, metric string, value float64) (Event, error) {
+	switch statType {
+	case "c":
+		return &CounterEvent{
+			metricName: metric,
+			value:      float64(value),
+		}, nil
+	case "g":
+		return &GaugeEvent{
+			metricName: metric,
+			value:      float64(value),
+		}, nil
+	case "ms":
+		return &TimerEvent{
+			metricName: metric,
+			value:      float64(value),
+		}, nil
+	case "s":
+		return nil, fmt.Errorf("No support for StatsD sets")
+	default:
+		return nil, fmt.Errorf("Bad stat type %s", statType)
+	}
+}
+
 func (l *StatsDListener) Listen(e chan<- Events) {
 	// TODO: evaluate proper size according to MTU
 	var buf [512]byte
@@ -214,7 +230,7 @@ func (l *StatsDListener) handlePacket(packet []byte, e chan<- Events) {
 				continue
 			}
 			valueStr, statType := components[0], components[1]
-			value, err := strconv.Atoi(valueStr)
+			value, err := strconv.ParseFloat(valueStr, 64)
 			if err != nil {
 				log.Printf("Bad value %s on line: %s", valueStr, line)
 				continue
@@ -239,35 +255,17 @@ func (l *StatsDListener) handlePacket(packet []byte, e chan<- Events) {
 					log.Printf("Invalid zero sampling factor %s on line %s, setting to 1", samplingStr, line)
 					samplingFactor = 1
 				}
+				value /= samplingFactor
 			}
 
-			var event Event
-			switch statType {
-			case "c":
-				event = &CounterEvent{
-					metricName: metric,
-					value:      float64(value) / samplingFactor,
+			event, err := buildEvent(statType, metric, value)
+			if err != nil {
+				log.Printf("Error building event on line %s: %s", line, err)
+				continue
 			}
-			case "g":
-				event = &GaugeEvent{
-					metricName: metric,
-					value:      float64(value),
-				}
-			case "ms":
-				event = &TimerEvent{
-					metricName: metric,
-					value:      float64(value),
-				}
-			case "s":
-				log.Println("No support for StatsD sets in line", line)
-			default:
-				log.Printf("Bad stat type %s on line: %s", statType, line)
-			}
-			if event != nil {
 			events = append(events, event)
 		}
 	}
-	}
 	e <- events
 }
 
@@ -319,5 +317,10 @@ func main() {
 	go l.Listen(events)
 
 	bridge := NewBridge()
+	go func() {
+		for _ = range time.Tick(*summaryFlushInterval) {
+			bridge.Summaries.Flush()
+		}
+	}()
 	bridge.Listen(events)
 }