writefreely/updates.go

107 lines
2.9 KiB
Go

/*
* Copyright © 2018-2019 A Bunch Tell LLC.
*
* This file is part of WriteFreely.
*
* WriteFreely is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, included
* in the LICENSE file in this source code package.
*/
package writefreely
import (
"io/ioutil"
"net/http"
"strings"
"sync"
"time"
)
// updatesCacheTime is the default interval between cache updates for new
// software versions
const defaultUpdatesCacheTime = 12 * time.Hour
// updatesCache holds data about current and new releases of the writefreely
// software
type updatesCache struct {
mu sync.Mutex
frequency time.Duration
lastCheck time.Time
latestVersion string
currentVersion string
}
// CheckNow asks for the latest released version of writefreely and updates
// the cache last checked time. If the version postdates the current 'latest'
// the version value is replaced.
func (uc *updatesCache) CheckNow() error {
uc.mu.Lock()
defer uc.mu.Unlock()
latestRemote, err := newVersionCheck()
if err != nil {
return err
}
uc.lastCheck = time.Now()
if CompareSemver(latestRemote, uc.latestVersion) == 1 {
uc.latestVersion = latestRemote
}
return nil
}
// AreAvailable updates the cache if the frequency duration has passed
// then returns if the latest release is newer than the current running version.
func (uc updatesCache) AreAvailable() bool {
if time.Since(uc.lastCheck) > uc.frequency {
uc.CheckNow()
}
return CompareSemver(uc.latestVersion, uc.currentVersion) == 1
}
// LatestVersion returns the latest stored version available.
func (uc updatesCache) LatestVersion() string {
return uc.latestVersion
}
// ReleaseURL returns the full URL to the blog.writefreely.org release notes
// for the latest version as stored in the cache.
func (uc updatesCache) ReleaseURL() string {
ver := strings.TrimPrefix(uc.latestVersion, "v")
ver = strings.TrimSuffix(ver, ".0")
// hack until go 1.12 in build/travis
seg := strings.Split(ver, ".")
return "https://blog.writefreely.org/version-" + strings.Join(seg, "-")
}
// newUpdatesCache returns an initialized updates cache
func newUpdatesCache(expiry time.Duration) *updatesCache {
cache := updatesCache{
frequency: expiry,
currentVersion: "v" + softwareVer,
}
cache.CheckNow()
return &cache
}
// InitUpdates initializes the updates cache, if the config value is set
// It uses the defaultUpdatesCacheTime for the cache expiry
func (app *App) InitUpdates() {
if app.cfg.App.UpdateChecks {
app.updates = newUpdatesCache(defaultUpdatesCacheTime)
}
}
func newVersionCheck() (string, error) {
res, err := http.Get("https://version.writefreely.org")
if err == nil && res.StatusCode == http.StatusOK {
defer res.Body.Close()
body, err := ioutil.ReadAll(res.Body)
if err != nil {
return "", err
}
return string(body), nil
}
return "", err
}