cadvisor/container/docker/fsHandler.go
2016-01-15 15:40:15 -08:00

119 lines
2.7 KiB
Go

// Copyright 2015 Google Inc. All Rights Reserved.
//
// 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.
// Handler for Docker containers.
package docker
import (
"sync"
"time"
"github.com/google/cadvisor/fs"
"github.com/golang/glog"
)
type fsHandler interface {
start()
usage() (uint64, uint64)
stop()
}
type realFsHandler struct {
sync.RWMutex
lastUpdate time.Time
usageBytes uint64
baseUsageBytes uint64
period time.Duration
rootfs string
extraDir string
fsInfo fs.FsInfo
// Tells the container to stop.
stopChan chan struct{}
}
const longDu = time.Second
var _ fsHandler = &realFsHandler{}
func newFsHandler(period time.Duration, rootfs, extraDir string, fsInfo fs.FsInfo) fsHandler {
return &realFsHandler{
lastUpdate: time.Time{},
usageBytes: 0,
baseUsageBytes: 0,
period: period,
rootfs: rootfs,
extraDir: extraDir,
fsInfo: fsInfo,
stopChan: make(chan struct{}, 1),
}
}
func (fh *realFsHandler) needsUpdate() bool {
return time.Now().After(fh.lastUpdate.Add(fh.period))
}
func (fh *realFsHandler) update() error {
// TODO(vishh): Add support for external mounts.
baseUsage, err := fh.fsInfo.GetDirUsage(fh.rootfs)
if err != nil {
return err
}
extraDirUsage, err := fh.fsInfo.GetDirUsage(fh.extraDir)
if err != nil {
return err
}
fh.Lock()
defer fh.Unlock()
fh.lastUpdate = time.Now()
fh.usageBytes = baseUsage + extraDirUsage
fh.baseUsageBytes = baseUsage
return nil
}
func (fh *realFsHandler) trackUsage() {
fh.update()
for {
select {
case <-fh.stopChan:
return
case <-time.After(fh.period):
start := time.Now()
if err := fh.update(); err != nil {
glog.V(2).Infof("failed to collect filesystem stats - %v", err)
}
duration := time.Since(start)
if duration > longDu {
glog.V(3).Infof("`du` on following dirs took %v: %v", duration, []string{fh.rootfs, fh.extraDir})
}
}
}
}
func (fh *realFsHandler) start() {
go fh.trackUsage()
}
func (fh *realFsHandler) stop() {
close(fh.stopChan)
}
func (fh *realFsHandler) usage() (baseUsageBytes, totalUsageBytes uint64) {
fh.RLock()
defer fh.RUnlock()
return fh.baseUsageBytes, fh.usageBytes
}