go/internal/log: New package (draft)

Package log provides logging with severity levels and integration with tasks.

go/internal/log/log.go

+// Copyright (C) 2017-2021  Nexedi SA and Contributors.
+//                          Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
+// Package log provides logging with severity levels and tasks integration.
+//
+// It is inspired by cockroach/util/log package.
+package log
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/golang/glog"
+
+	"lab.nexedi.com/kirr/neo/go/internal/xcontext/task"
+)
+
+// withTask prepends string describing current operational task stack to argv and returns it.
+//
+// handy to use this way:
+//
+//	func info(ctx, argv ...interface{}) {
+//		glog.Info(withTask(ctx, argv...)...)
+//	}
+//
+// see https://golang.org/issues/21388.
+func withTask(ctx context.Context, argv ...interface{}) []interface{} {
+	task := task.Current(ctx).String()
+	if task == "" {
+		return argv
+	}
+
+	if len(argv) != 0 {
+		task += ": "
+	}
+
+	return append([]interface{}{task}, argv...)
+}
+
+
+
+type Depth int
+
+func (d Depth) Info(ctx context.Context, argv ...interface{}) {
+	// TODO avoid task formatting if logging severity disabled
+	glog.InfoDepth(int(d+1), withTask(ctx, argv...)...)
+}
+
+func (d Depth) Infof(ctx context.Context, format string, argv ...interface{}) {
+	// TODO avoid formatting if logging severity disabled
+	glog.InfoDepth(int(d+1), withTask(ctx, fmt.Sprintf(format, argv...))...)
+}
+
+func (d Depth) Warning(ctx context.Context, argv ...interface{}) {
+	glog.WarningDepth(int(d+1), withTask(ctx, argv...)...)
+}
+
+func (d Depth) Warningf(ctx context.Context, format string, argv ...interface{}) {
+	glog.WarningDepth(int(d+1), withTask(ctx, fmt.Sprintf(format, argv...))...)
+}
+
+func (d Depth) Error(ctx context.Context, argv ...interface{}) {
+	glog.ErrorDepth(int(d+1), withTask(ctx, argv...)...)
+}
+
+func (d Depth) Errorf(ctx context.Context, format string, argv ...interface{}) {
+	glog.ErrorDepth(int(d+1), withTask(ctx, fmt.Sprintf(format, argv...))...)
+}
+
+func (d Depth) Fatal(ctx context.Context, argv ...interface{}) {
+	glog.FatalDepth(int(d+1), withTask(ctx, argv...)...)
+}
+
+func (d Depth) Fatalf(ctx context.Context, format string, argv ...interface{}) {
+	glog.FatalDepth(int(d+1), withTask(ctx, fmt.Sprintf(format, argv...))...)
+}
+
+
+func Info(ctx context.Context, argv ...interface{})	{ Depth(1).Info(ctx, argv...) }
+func Warning(ctx context.Context, argv ...interface{})	{ Depth(1).Warning(ctx, argv...) }
+func Error(ctx context.Context, argv ...interface{})	{ Depth(1).Error(ctx, argv...) }
+func Fatal(ctx context.Context, argv ...interface{})	{ Depth(1).Fatal(ctx, argv...) }
+
+func Infof(ctx context.Context, format string, argv ...interface{}) {
+	Depth(1).Infof(ctx, format, argv...)
+}
+
+func Warningf(ctx context.Context, format string, argv ...interface{}) {
+	Depth(1).Warningf(ctx, format, argv...)
+}
+
+func Errorf(ctx context.Context, format string, argv ...interface{}) {
+	Depth(1).Errorf(ctx, format, argv...)
+}
+
+func Fatalf(ctx context.Context, format string, argv ...interface{}) {
+	Depth(1).Fatalf(ctx, format, argv...)
+}
+
+func Flush()	{ glog.Flush() }