Merge pull request #4 from cabify/colega/no-debug-logger

Added NoDebugLogger that doesn't format debug logs

Author: colega

no_debug_logger.go

@@ -0,0 +1,12 @@
+package log
+
+// NoDebugLogger embeds a Logger, but in calls to debug functions it does nothing.
+// It avoids doing fmt.Sprintf() for those calls as they will be discarded anyways.
+// This makes those calls like 50 times faster (see benchmark file)
+type NoDebugLogger struct {
+	Logger
+}
+
+func (NoDebugLogger) Debug(args ...interface{})                 {}
+func (NoDebugLogger) Debugf(format string, args ...interface{}) {}
+func (NoDebugLogger) Debugln(args ...interface{})               {}

no_debug_logger_bench_test.go

@@ -0,0 +1,50 @@
+package log
+
+import (
+	"testing"
+)
+
+/*
+$ go test -bench=. ./...
+     | goos: darwin
+     | goarch: amd64
+     | pkg: github.com/cabify/go-logging
+     | BenchmarkPlainLoggerDebugSpeed-4      	30000000	        45.9 ns/op
+     | BenchmarkNoDebugLoggerDebugSpeed-4    	2000000000	         0.33 ns/op
+     | BenchmarkPlainLoggerDebugfSpeed-4     	20000000	        80.8 ns/op
+     | BenchmarkNoDebugLoggerDebugfSpeed-4   	50000000	        36.5 ns/op
+*/
+
+type someStruct struct {
+	value float64
+}
+
+var (
+	structValue           = someStruct{value: 10.0}
+	plainLoggerInstance   = NewLogger("test")
+	noDebugLoggerInstance = NoDebugLogger{Logger: plainLoggerInstance}
+)
+
+func BenchmarkPlainLoggerDebugSpeed(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		plainLoggerInstance.Debug("Something")
+	}
+}
+
+func BenchmarkNoDebugLoggerDebugSpeed(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		noDebugLoggerInstance.Debug("Something")
+	}
+}
+
+func BenchmarkPlainLoggerDebugfSpeed(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		plainLoggerInstance.Debugf("Something %v, %d", structValue, i)
+	}
+}
+
+func BenchmarkNoDebugLoggerDebugfSpeed(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		noDebugLoggerInstance.Debugf("Something %v, %d", structValue, i)
+	}
+}