minio/cmd/utils.go
2016-08-21 12:06:53 -07:00

213 lines
5.8 KiB
Go

/*
* Minio Cloud Storage, (C) 2015 Minio, Inc.
*
* 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 cmd
import (
"encoding/base64"
"encoding/xml"
"errors"
"io"
"os"
"os/exec"
"strings"
"sync"
"syscall"
)
// xmlDecoder provide decoded value in xml.
func xmlDecoder(body io.Reader, v interface{}, size int64) error {
var lbody io.Reader
if size > 0 {
lbody = io.LimitReader(body, size)
} else {
lbody = body
}
d := xml.NewDecoder(lbody)
return d.Decode(v)
}
// checkValidMD5 - verify if valid md5, returns md5 in bytes.
func checkValidMD5(md5 string) ([]byte, error) {
return base64.StdEncoding.DecodeString(strings.TrimSpace(md5))
}
/// http://docs.aws.amazon.com/AmazonS3/latest/dev/UploadingObjects.html
const (
// maximum object size per PUT request is 5GiB
maxObjectSize = 1024 * 1024 * 1024 * 5
// minimum Part size for multipart upload is 5MB
minPartSize = 1024 * 1024 * 5
// maximum Part ID for multipart upload is 10000 (Acceptable values range from 1 to 10000 inclusive)
maxPartID = 10000
)
// isMaxObjectSize - verify if max object size
func isMaxObjectSize(size int64) bool {
return size > maxObjectSize
}
// Check if part size is more than or equal to minimum allowed size.
func isMinAllowedPartSize(size int64) bool {
return size >= minPartSize
}
// isMaxPartNumber - Check if part ID is greater than the maximum allowed ID.
func isMaxPartID(partID int) bool {
return partID > maxPartID
}
func contains(stringList []string, element string) bool {
for _, e := range stringList {
if e == element {
return true
}
}
return false
}
// Represents a type of an exit func which will be invoked upon shutdown signal.
type onExitFunc func(code int)
// Represents a type for all the the callback functions invoked upon shutdown signal.
type cleanupOnExitFunc func() errCode
// Represents a collection of various callbacks executed upon exit signals.
type shutdownCallbacks struct {
// Protect callbacks list from a concurrent access
*sync.RWMutex
// genericCallbacks - is the list of function callbacks executed one by one
// when a shutdown starts. A callback returns 0 for success and 1 for failure.
// Failure is considered an emergency error that needs an immediate exit
genericCallbacks []cleanupOnExitFunc
// objectLayerCallbacks - contains the list of function callbacks that
// need to be invoked when a shutdown starts. These callbacks will be called before
// the general callback shutdowns
objectLayerCallbacks []cleanupOnExitFunc
}
// globalShutdownCBs stores regular and object storages callbacks
var globalShutdownCBs *shutdownCallbacks
func (s shutdownCallbacks) GetObjectLayerCBs() []cleanupOnExitFunc {
s.RLock()
defer s.RUnlock()
return s.objectLayerCallbacks
}
func (s shutdownCallbacks) GetGenericCBs() []cleanupOnExitFunc {
s.RLock()
defer s.RUnlock()
return s.genericCallbacks
}
func (s *shutdownCallbacks) AddObjectLayerCB(callback cleanupOnExitFunc) error {
s.Lock()
defer s.Unlock()
if callback == nil {
return errInvalidArgument
}
s.objectLayerCallbacks = append(s.objectLayerCallbacks, callback)
return nil
}
func (s *shutdownCallbacks) AddGenericCB(callback cleanupOnExitFunc) error {
s.Lock()
defer s.Unlock()
if callback == nil {
return errInvalidArgument
}
s.genericCallbacks = append(s.genericCallbacks, callback)
return nil
}
// Initialize graceful shutdown mechanism.
func initGracefulShutdown(onExitFn onExitFunc) error {
// Validate exit func.
if onExitFn == nil {
return errInvalidArgument
}
globalShutdownCBs = &shutdownCallbacks{
RWMutex: &sync.RWMutex{},
}
// Return start monitor shutdown signal.
return startMonitorShutdownSignal(onExitFn)
}
type shutdownSignal int
const (
shutdownHalt = iota
shutdownRestart
)
// Global shutdown signal channel.
var globalShutdownSignalCh = make(chan shutdownSignal, 1)
// Start to monitor shutdownSignal to execute shutdown callbacks
func startMonitorShutdownSignal(onExitFn onExitFunc) error {
// Validate exit func.
if onExitFn == nil {
return errInvalidArgument
}
go func() {
defer close(globalShutdownSignalCh)
// Monitor signals.
trapCh := signalTrap(os.Interrupt, syscall.SIGTERM)
for {
select {
case <-trapCh:
// Initiate graceful shutdown.
globalShutdownSignalCh <- shutdownHalt
case signal := <-globalShutdownSignalCh:
// Call all object storage shutdown callbacks and exit for emergency
for _, callback := range globalShutdownCBs.GetObjectLayerCBs() {
exitCode := callback()
if exitCode != exitSuccess {
onExitFn(int(exitCode))
}
}
// Call all callbacks and exit for emergency
for _, callback := range globalShutdownCBs.GetGenericCBs() {
exitCode := callback()
if exitCode != exitSuccess {
onExitFn(int(exitCode))
}
}
// All shutdown callbacks ensure that the server is safely terminated
// and any concurrent process could be started again
if signal == shutdownRestart {
path := os.Args[0]
cmdArgs := os.Args[1:]
cmd := exec.Command(path, cmdArgs...)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
err := cmd.Start()
if err != nil {
errorIf(errors.New("Unable to reboot."), err.Error())
}
onExitFn(int(exitSuccess))
}
onExitFn(int(exitSuccess))
}
}
}()
// Successfully started routine.
return nil
}