Clean up stats configuration

chihaya.go

@@ -71,9 +71,7 @@ func Boot() {
 		glog.V(1).Infof("Loaded config file: %s", configPath)
 	}
 
-	stats.DefaultBufferSize = cfg.StatsBufferSize
+	stats.DefaultStats = stats.New(cfg.StatsConfig)
-	stats.DefaultIncludeMemStats = cfg.IncludeMemStats
-	stats.DefaultVerboseMemStats = cfg.VerboseMemStats
 
 	tkr, err := tracker.New(cfg)
 	if err != nil {

config/config.go

@@ -51,6 +51,14 @@ type NetConfig struct {
 	PreferredIPv6Subnet int  `json:"preferred_ipv6_subnet,omitempty"`
 }
 
+type StatsConfig struct {
+	BufferSize int  `json:"stats_buffer_size"`
+	IncludeMem bool `json:"include_mem_stats"`
+	VerboseMem bool `json:"verbose_mem_stats"`
+
+	MemUpdateInterval Duration `json:"mem_stats_interval"`
+}
+
 // Config is a configuration for a Server.
 type Config struct {
 	Addr    string       `json:"addr"`
@@ -66,11 +74,8 @@ type Config struct {
 	MinAnnounce     Duration `json:"min_announce"`
 	RequestTimeout  Duration `json:"request_timeout"`
 	NumWantFallback int      `json:"default_num_want"`
-	StatsBufferSize int      `json:"stats_buffer_size"`
-	IncludeMemStats bool     `json:"include_mem_stats"`
-	VerboseMemStats bool     `json:"verbose_mem_stats"`
-	MemStatInterval Duration `json:"mem_stats_interval"`
 
+	StatsConfig
 	NetConfig
 }
 
@@ -95,10 +100,14 @@ var DefaultConfig = Config{
 	MinAnnounce:     Duration{15 * time.Minute},
 	RequestTimeout:  Duration{10 * time.Second},
 	NumWantFallback: 50,
-	StatsBufferSize: 0,
+
-	IncludeMemStats: true,
+	StatsConfig: StatsConfig{
-	VerboseMemStats: false,
+		BufferSize: 0,
-	MemStatInterval: Duration{15 * time.Second},
+		IncludeMem: true,
+		VerboseMem: false,
+
+		MemUpdateInterval: Duration{5 * time.Second},
+	},
 
 	NetConfig: NetConfig{
 		AllowIPSpoofing:  true,

stats/mem.go

@@ -32,6 +32,9 @@ type BasicMemStats struct {
 	PauseTotalNs uint64
 }
 
+// MemStatsWrapper wraps runtime.MemStats with an optionally less verbose JSON
+// representation. The JSON field names correspond exactly to the runtime field
+// names to avoid reimplementing the entire struct.
 type MemStatsWrapper struct {
 	basic   *BasicMemStats
 	full    *runtime.MemStats
@@ -57,6 +60,7 @@ func (s *MemStatsWrapper) MarshalJSON() ([]byte, error) {
 	}
 }
 
+// Update fetches the current memstats from runtime and resets the cache.
 func (s *MemStatsWrapper) Update() {
 	runtime.ReadMemStats(s.full)
 

stats/stats.go

@@ -6,7 +6,11 @@
 // BitTorrent tracker.
 package stats
 
-import "time"
+import (
+	"time"
+
+	"github.com/chihaya/chihaya/config"
+)
 
 const (
 	Announce = iota
@@ -36,12 +40,7 @@ const (
 // DefaultStats is a default instance of stats tracking that uses an unbuffered
 // channel for broadcasting events unless specified otherwise via a command
 // line flag.
-var (
+var DefaultStats *Stats
-	DefaultStats           *Stats
-	DefaultBufferSize      int
-	DefaultIncludeMemStats bool
-	DefaultVerboseMemStats bool
-)
 
 type PeerStats struct {
 	// Stats for all peers.
@@ -94,14 +93,14 @@ type Stats struct {
 	recordMemStats     <-chan time.Time
 }
 
-func New(chanSize int, mem bool, verboseMem bool) *Stats {
+func New(cfg config.StatsConfig) *Stats {
 	s := &Stats{
 		Start:  time.Now(),
-		events: make(chan int, chanSize),
+		events: make(chan int, cfg.BufferSize),
 
-		ipv4PeerEvents:     make(chan int, chanSize),
+		ipv4PeerEvents:     make(chan int, cfg.BufferSize),
-		ipv6PeerEvents:     make(chan int, chanSize),
+		ipv6PeerEvents:     make(chan int, cfg.BufferSize),
-		responseTimeEvents: make(chan time.Duration, chanSize),
+		responseTimeEvents: make(chan time.Duration, cfg.BufferSize),
 
 		ResponseTime: PercentileTimes{
 			P50: NewPercentile(0.5),
@@ -110,9 +109,9 @@ func New(chanSize int, mem bool, verboseMem bool) *Stats {
 		},
 	}
 
-	if mem {
+	if cfg.IncludeMem {
-		s.MemStats = NewMemStatsWrapper(verboseMem)
+		s.MemStats = NewMemStatsWrapper(cfg.VerboseMem)
-		s.recordMemStats = time.NewTicker(time.Second * 10).C
+		s.recordMemStats = time.NewTicker(cfg.MemUpdateInterval.Duration).C
 	}
 
 	go s.handleEvents()
@@ -250,27 +249,15 @@ func (s *Stats) handlePeerEvent(ps *PeerStats, event int) {
 
 // RecordEvent broadcasts an event to the default stats queue.
 func RecordEvent(event int) {
-	if DefaultStats == nil {
-		DefaultStats = New(DefaultBufferSize, DefaultIncludeMemStats, DefaultVerboseMemStats)
-	}
-
 	DefaultStats.RecordEvent(event)
 }
 
 // RecordPeerEvent broadcasts a peer event to the default stats queue.
 func RecordPeerEvent(event int, ipv6 bool) {
-	if DefaultStats == nil {
-		DefaultStats = New(DefaultBufferSize, DefaultIncludeMemStats, DefaultVerboseMemStats)
-	}
-
 	DefaultStats.RecordPeerEvent(event, ipv6)
 }
 
 // RecordTiming broadcasts a timing event to the default stats queue.
 func RecordTiming(event int, duration time.Duration) {
-	if DefaultStats == nil {
-		DefaultStats = New(DefaultBufferSize, DefaultIncludeMemStats, DefaultVerboseMemStats)
-	}
-
 	DefaultStats.RecordTiming(event, duration)
 }