syncthing/internal/config/wrapper.go

270 lines
6.5 KiB
Go
Raw Normal View History

// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along
// with this program. If not, see <http://www.gnu.org/licenses/>.
package config
import (
"io/ioutil"
"os"
"path/filepath"
"sync"
"github.com/syncthing/syncthing/internal/events"
"github.com/syncthing/syncthing/internal/osutil"
"github.com/syncthing/syncthing/internal/protocol"
)
// An interface to handle configuration changes, and a wrapper type á la
// http.Handler
type Handler interface {
Changed(Configuration) error
}
type HandlerFunc func(Configuration) error
func (fn HandlerFunc) Changed(cfg Configuration) error {
return fn(cfg)
}
// A wrapper around a Configuration that manages loads, saves and published
// notifications of changes to registered Handlers
type ConfigWrapper struct {
cfg Configuration
path string
deviceMap map[protocol.DeviceID]DeviceConfiguration
folderMap map[string]FolderConfiguration
replaces chan Configuration
mut sync.Mutex
subs []Handler
sMut sync.Mutex
}
// Wrap wraps an existing Configuration structure and ties it to a file on
// disk.
func Wrap(path string, cfg Configuration) *ConfigWrapper {
w := &ConfigWrapper{cfg: cfg, path: path}
w.replaces = make(chan Configuration)
go w.Serve()
return w
}
// Load loads an existing file on disk and returns a new configuration
// wrapper.
func Load(path string, myID protocol.DeviceID) (*ConfigWrapper, error) {
fd, err := os.Open(path)
if err != nil {
return nil, err
}
defer fd.Close()
cfg, err := ReadXML(fd, myID)
if err != nil {
return nil, err
}
return Wrap(path, cfg), nil
}
// Serve handles configuration replace events and calls any interested
// handlers. It is started automatically by Wrap() and Load() and should not
// be run manually.
func (w *ConfigWrapper) Serve() {
for cfg := range w.replaces {
w.sMut.Lock()
subs := w.subs
w.sMut.Unlock()
for _, h := range subs {
h.Changed(cfg)
}
}
}
// Stop stops the Serve() loop. Set and Replace operations will panic after a
// Stop.
func (w *ConfigWrapper) Stop() {
close(w.replaces)
}
// Subscribe registers the given handler to be called on any future
// configuration changes.
func (w *ConfigWrapper) Subscribe(h Handler) {
w.sMut.Lock()
w.subs = append(w.subs, h)
w.sMut.Unlock()
}
// Raw returns the currently wrapped Configuration object.
func (w *ConfigWrapper) Raw() Configuration {
return w.cfg
}
// Replace swaps the current configuration object for the given one.
func (w *ConfigWrapper) Replace(cfg Configuration) {
w.mut.Lock()
defer w.mut.Unlock()
w.cfg = cfg
w.deviceMap = nil
w.folderMap = nil
w.replaces <- cfg
}
// Devices returns a map of devices. Device structures should not be changed,
// other than for the purpose of updating via SetDevice().
func (w *ConfigWrapper) Devices() map[protocol.DeviceID]DeviceConfiguration {
w.mut.Lock()
defer w.mut.Unlock()
if w.deviceMap == nil {
w.deviceMap = make(map[protocol.DeviceID]DeviceConfiguration, len(w.cfg.Devices))
for _, dev := range w.cfg.Devices {
w.deviceMap[dev.DeviceID] = dev
}
}
return w.deviceMap
}
// SetDevice adds a new device to the configuration, or overwrites an existing
// device with the same ID.
func (w *ConfigWrapper) SetDevice(dev DeviceConfiguration) {
w.mut.Lock()
defer w.mut.Unlock()
w.deviceMap = nil
for i := range w.cfg.Devices {
if w.cfg.Devices[i].DeviceID == dev.DeviceID {
w.cfg.Devices[i] = dev
w.replaces <- w.cfg
return
}
}
w.cfg.Devices = append(w.cfg.Devices, dev)
w.replaces <- w.cfg
}
// Devices returns a map of folders. Folder structures should not be changed,
// other than for the purpose of updating via SetFolder().
func (w *ConfigWrapper) Folders() map[string]FolderConfiguration {
w.mut.Lock()
defer w.mut.Unlock()
if w.folderMap == nil {
w.folderMap = make(map[string]FolderConfiguration, len(w.cfg.Folders))
for _, fld := range w.cfg.Folders {
path, err := osutil.ExpandTilde(fld.Path)
if err != nil {
l.Warnln("home:", err)
continue
}
fld.Path = path
w.folderMap[fld.ID] = fld
}
}
return w.folderMap
}
// SetFolder adds a new folder to the configuration, or overwrites an existing
// folder with the same ID.
func (w *ConfigWrapper) SetFolder(fld FolderConfiguration) {
w.mut.Lock()
defer w.mut.Unlock()
w.folderMap = nil
for i := range w.cfg.Folders {
if w.cfg.Folders[i].ID == fld.ID {
w.cfg.Folders[i] = fld
w.replaces <- w.cfg
return
}
}
w.cfg.Folders = append(w.cfg.Folders, fld)
w.replaces <- w.cfg
}
// Options returns the current options configuration object.
func (w *ConfigWrapper) Options() OptionsConfiguration {
w.mut.Lock()
defer w.mut.Unlock()
return w.cfg.Options
}
// SetOptions replaces the current options configuration object.
func (w *ConfigWrapper) SetOptions(opts OptionsConfiguration) {
w.mut.Lock()
defer w.mut.Unlock()
w.cfg.Options = opts
w.replaces <- w.cfg
}
// GUI returns the current GUI configuration object.
func (w *ConfigWrapper) GUI() GUIConfiguration {
w.mut.Lock()
defer w.mut.Unlock()
return w.cfg.GUI
}
// SetGUI replaces the current GUI configuration object.
func (w *ConfigWrapper) SetGUI(gui GUIConfiguration) {
w.mut.Lock()
defer w.mut.Unlock()
w.cfg.GUI = gui
w.replaces <- w.cfg
}
// InvalidateFolder sets the invalid marker on the given folder.
func (w *ConfigWrapper) InvalidateFolder(id string, err string) {
w.mut.Lock()
defer w.mut.Unlock()
w.folderMap = nil
for i := range w.cfg.Folders {
if w.cfg.Folders[i].ID == id {
w.cfg.Folders[i].Invalid = err
w.replaces <- w.cfg
return
}
}
}
// Save writes the configuration to disk, and generates a ConfigSaved event.
func (w *ConfigWrapper) Save() error {
fd, err := ioutil.TempFile(filepath.Dir(w.path), "cfg")
if err != nil {
return err
}
err = w.cfg.WriteXML(fd)
if err != nil {
fd.Close()
return err
}
err = fd.Close()
if err != nil {
return err
}
events.Default.Log(events.ConfigSaved, w.cfg)
return osutil.Rename(fd.Name(), w.path)
}