Add standard (global) statsd client

std.go

@@ -0,0 +1,55 @@
+package statsd
+
+import "sync"
+
+var std Statsd
+var mu sync.Mutex
+
+func init() {
+	Unconfigure()
+}
+
+// Configure creates a global StatsD client.
+// TODO: Use a buffered client instead!
+func Configure(host string, prefix string) error {
+	mu.Lock()
+	defer mu.Unlock()
+
+	client := NewStatsdClient(host, prefix)
+	err := client.CreateSocket()
+	if err != nil {
+		return err
+	}
+
+	std = client
+	return nil
+}
+
+// Unconfigure resets the global StatsD client to its default state, which is
+// to silently drop all events.
+func Unconfigure() {
+	std = &NoopClient{}
+}
+
+// These functions write to the global StatsD client if one has been configured,
+// otherwise do nothing.
+
+func Incr(stat string, count int64) error {
+	return std.Incr(stat, count)
+}
+
+func Decr(stat string, count int64) error {
+	return std.Decr(stat, count)
+}
+
+func Timing(stat string, delta int64) error {
+	return std.Timing(stat, delta)
+}
+
+func Absolute(stat string, value int64) error {
+	return std.Absolute(stat, value)
+}
+
+func Total(stat string, value int64) error {
+	return std.Total(stat, value)
+}

std_test.go

@@ -0,0 +1,29 @@
+package statsd
+
+import (
+	"testing"
+)
+
+func TestConfigure(t *testing.T) {
+
+	// assert that global is a noop client
+	_, ok := std.(*NoopClient)
+	if !ok {
+		t.Errorf("expected std to be a NoopClient, got a %#v", std)
+	}
+
+	// assert that after calling Configure, the global is a StatsdClient
+	Configure("localhost:8888", "prefix")
+	_, ok = std.(*StatsdClient)
+	if !ok {
+		t.Errorf("expected std to be a StatsdClient, got a %#v", std)
+	}
+
+	// assert that after calling Unconfigure, the global is back to being a
+	// NoopClient
+	Unconfigure()
+	_, ok = std.(*NoopClient)
+	if !ok {
+		t.Errorf("expected std to be a NoopClient, got a %#v", std)
+	}
+}