[VOL-2538] Logging - Implement dynamic log levels in ofagent
Change-Id: I9582230d9d3c34ea84339fddf2b2f3b3d2804808
diff --git a/vendor/go.etcd.io/etcd/pkg/logutil/merge_logger.go b/vendor/go.etcd.io/etcd/pkg/logutil/merge_logger.go
new file mode 100644
index 0000000..866b6f7
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/logutil/merge_logger.go
@@ -0,0 +1,194 @@
+// Copyright 2015 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 logutil
+
+import (
+ "fmt"
+ "sync"
+ "time"
+
+ "github.com/coreos/pkg/capnslog"
+)
+
+var (
+ defaultMergePeriod = time.Second
+ defaultTimeOutputScale = 10 * time.Millisecond
+
+ outputInterval = time.Second
+)
+
+// line represents a log line that can be printed out
+// through capnslog.PackageLogger.
+type line struct {
+ level capnslog.LogLevel
+ str string
+}
+
+func (l line) append(s string) line {
+ return line{
+ level: l.level,
+ str: l.str + " " + s,
+ }
+}
+
+// status represents the merge status of a line.
+type status struct {
+ period time.Duration
+
+ start time.Time // start time of latest merge period
+ count int // number of merged lines from starting
+}
+
+func (s *status) isInMergePeriod(now time.Time) bool {
+ return s.period == 0 || s.start.Add(s.period).After(now)
+}
+
+func (s *status) isEmpty() bool { return s.count == 0 }
+
+func (s *status) summary(now time.Time) string {
+ ts := s.start.Round(defaultTimeOutputScale)
+ took := now.Round(defaultTimeOutputScale).Sub(ts)
+ return fmt.Sprintf("[merged %d repeated lines in %s]", s.count, took)
+}
+
+func (s *status) reset(now time.Time) {
+ s.start = now
+ s.count = 0
+}
+
+// MergeLogger supports merge logging, which merges repeated log lines
+// and prints summary log lines instead.
+//
+// For merge logging, MergeLogger prints out the line when the line appears
+// at the first time. MergeLogger holds the same log line printed within
+// defaultMergePeriod, and prints out summary log line at the end of defaultMergePeriod.
+// It stops merging when the line doesn't appear within the
+// defaultMergePeriod.
+type MergeLogger struct {
+ *capnslog.PackageLogger
+
+ mu sync.Mutex // protect statusm
+ statusm map[line]*status
+}
+
+func NewMergeLogger(logger *capnslog.PackageLogger) *MergeLogger {
+ l := &MergeLogger{
+ PackageLogger: logger,
+ statusm: make(map[line]*status),
+ }
+ go l.outputLoop()
+ return l
+}
+
+func (l *MergeLogger) MergeInfo(entries ...interface{}) {
+ l.merge(line{
+ level: capnslog.INFO,
+ str: fmt.Sprint(entries...),
+ })
+}
+
+func (l *MergeLogger) MergeInfof(format string, args ...interface{}) {
+ l.merge(line{
+ level: capnslog.INFO,
+ str: fmt.Sprintf(format, args...),
+ })
+}
+
+func (l *MergeLogger) MergeNotice(entries ...interface{}) {
+ l.merge(line{
+ level: capnslog.NOTICE,
+ str: fmt.Sprint(entries...),
+ })
+}
+
+func (l *MergeLogger) MergeNoticef(format string, args ...interface{}) {
+ l.merge(line{
+ level: capnslog.NOTICE,
+ str: fmt.Sprintf(format, args...),
+ })
+}
+
+func (l *MergeLogger) MergeWarning(entries ...interface{}) {
+ l.merge(line{
+ level: capnslog.WARNING,
+ str: fmt.Sprint(entries...),
+ })
+}
+
+func (l *MergeLogger) MergeWarningf(format string, args ...interface{}) {
+ l.merge(line{
+ level: capnslog.WARNING,
+ str: fmt.Sprintf(format, args...),
+ })
+}
+
+func (l *MergeLogger) MergeError(entries ...interface{}) {
+ l.merge(line{
+ level: capnslog.ERROR,
+ str: fmt.Sprint(entries...),
+ })
+}
+
+func (l *MergeLogger) MergeErrorf(format string, args ...interface{}) {
+ l.merge(line{
+ level: capnslog.ERROR,
+ str: fmt.Sprintf(format, args...),
+ })
+}
+
+func (l *MergeLogger) merge(ln line) {
+ l.mu.Lock()
+
+ // increase count if the logger is merging the line
+ if status, ok := l.statusm[ln]; ok {
+ status.count++
+ l.mu.Unlock()
+ return
+ }
+
+ // initialize status of the line
+ l.statusm[ln] = &status{
+ period: defaultMergePeriod,
+ start: time.Now(),
+ }
+ // release the lock before IO operation
+ l.mu.Unlock()
+ // print out the line at its first time
+ l.PackageLogger.Logf(ln.level, ln.str)
+}
+
+func (l *MergeLogger) outputLoop() {
+ for now := range time.Tick(outputInterval) {
+ var outputs []line
+
+ l.mu.Lock()
+ for ln, status := range l.statusm {
+ if status.isInMergePeriod(now) {
+ continue
+ }
+ if status.isEmpty() {
+ delete(l.statusm, ln)
+ continue
+ }
+ outputs = append(outputs, ln.append(status.summary(now)))
+ status.reset(now)
+ }
+ l.mu.Unlock()
+
+ for _, o := range outputs {
+ l.PackageLogger.Logf(o.level, o.str)
+ }
+ }
+}