Changeset 709 in code for trunk/server.go

Timestamp:

Nov 17, 2021, 2:58:19 PM (4 years ago)

Author:

contact

Message:

Add int64 gauge abstraction

We want to serve metrics via both BouncerServ and Prometheus. Add
a tiny abstraction to avoid updating multiple metrics at once.

File:

• trunk/server.go (modified) (6 diffs)

trunk/server.go

@@ -57 +57 @@
 }
 
+type int64Gauge struct {
+        v int64 // atomic
+}
+
+func (g *int64Gauge) Add(delta int64) {
+        atomic.AddInt64(&g.v, delta)
+}
+
+func (g *int64Gauge) Value() int64 {
+        return atomic.LoadInt64(&g.v)
+}
+
+func (g *int64Gauge) Float64() float64 {
+        return float64(g.Value())
+}
+
 type Config struct {
         Hostname        string
@@ -75 +91 @@
         MetricsRegistry prometheus.Registerer // can be nil
 
-        config    atomic.Value // *Config
-        db        Database
-        stopWG    sync.WaitGroup
-        connCount int64 // atomic
+        config atomic.Value // *Config
+        db     Database
+        stopWG sync.WaitGroup
 
         lock      sync.Mutex
         listeners map[net.Listener]struct{}
         users     map[string]*user
+
+        metrics struct {
+                downstreams int64Gauge
+        }
 }
 
@@ -145 +164 @@
                 Name: "soju_downstreams_active",
                 Help: "Current number of downstream connections",
-        }, func() float64 {
-                return float64(atomic.LoadInt64(&s.connCount))
-        })
+        }, s.metrics.downstreams.Float64)
 }
 
@@ -235 +252 @@
         }()
 
-        atomic.AddInt64(&s.connCount, 1)
+        s.metrics.downstreams.Add(1)
         id := atomic.AddUint64(&lastDownstreamID, 1)
         dc := newDownstreamConn(s, ic, id)
@@ -250 +267 @@
         }
         dc.Close()
-        atomic.AddInt64(&s.connCount, -1)
+        s.metrics.downstreams.Add(-1)
 }
 
@@ -334 +351 @@
         stats.Users = len(s.users)
         s.lock.Unlock()
-        stats.Downstreams = atomic.LoadInt64(&s.connCount)
+        stats.Downstreams = s.metrics.downstreams.Value()
         return &stats
 }