Cleanup glog and add real caller information.

In general, we've learned that logging must be avoided at all
costs in the hot path. It's unlikely that the optimizations
here were significant in any case, since buffer would certainly
escape.

This also adds a test to ensure that the caller identification
works as expected, and so that logging can be benchmarked.

Original:
BenchmarkGoogleLogging-6   	 1222255	       949 ns/op

With this change:
BenchmarkGoogleLogging-6   	  517323	      2346 ns/op

Fixes #184

PiperOrigin-RevId: 291815420

1 files changed, 35 insertions, 0 deletions

diff --git a/pkg/log/log_test.go b/pkg/log/log_test.go
index 0634e7c1f..402cc29ae 100644
--- a/pkg/log/log_test.go
+++ b/pkg/log/log_test.go
@@ -16,18 +16,23 @@ package log
 
 import (
 	"fmt"
+	"strings"
 	"testing"
 )
 
 type testWriter struct {
 	lines []string
 	fail  bool
+	limit int
 }
 
 func (w *testWriter) Write(bytes []byte) (int, error) {
 	if w.fail {
 		return 0, fmt.Errorf("simulated failure")
 	}
+	if w.limit > 0 && len(w.lines) >= w.limit {
+		return len(bytes), nil
+	}
 	w.lines = append(w.lines, string(bytes))
 	return len(bytes), nil
 }
@@ -68,3 +73,33 @@ func TestDropMessages(t *testing.T) {
 		}
 	}
 }
+
+func TestCaller(t *testing.T) {
+	tw := &testWriter{}
+	e := &GoogleEmitter{Writer: Writer{Next: tw}}
+	bl := &BasicLogger{
+		Emitter: e,
+		Level:   Debug,
+	}
+	bl.Debugf("testing...\n") // Just for file + line.
+	if len(tw.lines) != 1 {
+		t.Errorf("expected 1 line, got %d", len(tw.lines))
+	}
+	if !strings.Contains(tw.lines[0], "log_test.go") {
+		t.Errorf("expected log_test.go, got %q", tw.lines[0])
+	}
+}
+
+func BenchmarkGoogleLogging(b *testing.B) {
+	tw := &testWriter{
+		limit: 1, // Only record one message.
+	}
+	e := &GoogleEmitter{Writer: Writer{Next: tw}}
+	bl := &BasicLogger{
+		Emitter: e,
+		Level:   Debug,
+	}
+	for i := 0; i < b.N; i++ {
+		bl.Debugf("hello %d, %d, %d", 1, 2, 3)
+	}
+}