pkg/logger: initial commit

Later to be used with "snapshot" and "clientv3" packages.

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

pkg/logger/discard.go

@@ -0,0 +1,38 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package logger
+
+import "log"
+
+// NewDiscardLogger returns a new Logger that discards everything except "fatal".
+func NewDiscardLogger() Logger { return &discardLogger{} }
+
+type discardLogger struct{}
+
+func (l *discardLogger) Info(args ...interface{})                    {}
+func (l *discardLogger) Infoln(args ...interface{})                  {}
+func (l *discardLogger) Infof(format string, args ...interface{})    {}
+func (l *discardLogger) Warning(args ...interface{})                 {}
+func (l *discardLogger) Warningln(args ...interface{})               {}
+func (l *discardLogger) Warningf(format string, args ...interface{}) {}
+func (l *discardLogger) Error(args ...interface{})                   {}
+func (l *discardLogger) Errorln(args ...interface{})                 {}
+func (l *discardLogger) Errorf(format string, args ...interface{})   {}
+func (l *discardLogger) Fatal(args ...interface{})                   { log.Fatal(args...) }
+func (l *discardLogger) Fatalln(args ...interface{})                 { log.Fatalln(args...) }
+func (l *discardLogger) Fatalf(format string, args ...interface{})   { log.Fatalf(format, args...) }
+func (l *discardLogger) V(lvl int) bool {
+	return false
+}

pkg/logger/doc.go

@@ -0,0 +1,16 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package logger implements various logging utilities.
+package logger

pkg/logger/logger.go

@@ -0,0 +1,22 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package logger
+
+import "google.golang.org/grpc/grpclog"
+
+// Logger defines logging interface.
+// TODO: add "Lvl(lvl int)" for clientv3 loggers.
+// TODO: make this settable with "Set" method.
+type Logger grpclog.LoggerV2

pkg/logger/package_logger.go

@@ -0,0 +1,51 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package logger
+
+import "github.com/coreos/pkg/capnslog"
+
+// NewPackageLogger wraps "*capnslog.PackageLogger" that implements "Logger" interface.
+//
+// For example:
+//
+//  var defaultLogger Logger
+//  plog := capnslog.NewPackageLogger("github.com/coreos/etcd", "snapshot")
+//  defaultLogger = NewPackageLogger(plog)
+//
+func NewPackageLogger(p *capnslog.PackageLogger) Logger {
+	// assert that Logger satisfies grpclog.LoggerV2
+	var _ Logger = &packageLogger{}
+	return &packageLogger{p: p}
+}
+
+type packageLogger struct {
+	p *capnslog.PackageLogger
+}
+
+func (l *packageLogger) Info(args ...interface{})                    { l.p.Info(args...) }
+func (l *packageLogger) Infoln(args ...interface{})                  { l.p.Info(args...) }
+func (l *packageLogger) Infof(format string, args ...interface{})    { l.p.Infof(format, args...) }
+func (l *packageLogger) Warning(args ...interface{})                 { l.p.Warning(args...) }
+func (l *packageLogger) Warningln(args ...interface{})               { l.p.Warning(args...) }
+func (l *packageLogger) Warningf(format string, args ...interface{}) { l.p.Warningf(format, args...) }
+func (l *packageLogger) Error(args ...interface{})                   { l.p.Error(args...) }
+func (l *packageLogger) Errorln(args ...interface{})                 { l.p.Error(args...) }
+func (l *packageLogger) Errorf(format string, args ...interface{})   { l.p.Errorf(format, args...) }
+func (l *packageLogger) Fatal(args ...interface{})                   { l.p.Fatal(args...) }
+func (l *packageLogger) Fatalln(args ...interface{})                 { l.p.Fatal(args...) }
+func (l *packageLogger) Fatalf(format string, args ...interface{})   { l.p.Fatalf(format, args...) }
+func (l *packageLogger) V(lvl int) bool {
+	return l.p.LevelAt(capnslog.LogLevel(lvl))
+}