utils.go

/*
Copyright 2014 Rohith 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.
*/

package marathon

import (
	"errors"
	"fmt"
	"net"
	"strings"
	"sync/atomic"
	"time"
)

type AtomicSwitch int64

func (p *AtomicSwitch) IsSwitched() bool {
	return atomic.LoadInt64((*int64)(p)) != 0
}

func (p *AtomicSwitch) SwitchOn() {
	atomic.StoreInt64((*int64)(p), 1)
}

func (p *AtomicSwitch) SwitchedOff() {
	atomic.StoreInt64((*int64)(p), 0)
}

func validateID(id string) string {
	if !strings.HasPrefix(id, "/") {
		return fmt.Sprintf("/%s", id)
	}
	return id
}

func trimRootPath(id string) string {
	if strings.HasPrefix(id, "/") {
		return strings.TrimPrefix(id, "/")
	}
	return id
}

func deadline(timeout time.Duration, work func(chan bool) error) error {
	result := make(chan error)
	timer := time.After(timeout)
	stop_channel := make(chan bool)

	// allow the method to attempt
	go func() {
		result <- work(stop_channel)
	}()
	for {
		select {
		case err := <-result:
			return err
		case <-timer:
			stop_channel <- true
			return ErrTimeoutError
		}
	}
}

func getInterfaceAddress(name string) (string, error) {
	if interfaces, err := net.Interfaces(); err != nil {
		return "", err
	} else {
		for _, iface := range interfaces {
			/* step: get only the interface we're interested in */
			if iface.Name == name {
				addrs, err := iface.Addrs()
				if err != nil {
					return "", err
				}
				/* step: return the first address */
				if len(addrs) > 0 {
					return strings.SplitN(addrs[0].String(), "/", 2)[0], nil
				}
			}
		}
	}
	return "", errors.New("Unable to determine or find the interface")
}

func contains(elements []string, value string) bool {
	for _, element := range elements {
		if element == value {
			return true
		}
	}
	return false
}