+++ /dev/null
-// Copyright (c) 2014-2015 The Notify Authors. All rights reserved.
-// Use of this source code is governed by the MIT license that can be
-// found in the LICENSE file.
-
-// +build darwin,kqueue dragonfly freebsd netbsd openbsd solaris
-
-// watcher_trigger is used for FEN and kqueue which behave similarly:
-// only files and dirs can be watched directly, but not files inside dirs.
-// As a result Create events have to be generated by implementation when
-// after Write event is returned for watched dir, it is rescanned and Create
-// event is returned for new files and these are automatically added
-// to watchlist. In case of removal of watched directory, native system returns
-// events for all files, but for Rename, they also need to be generated.
-// As a result native system works as something like trigger for rescan,
-// but contains additional data about dir in which changes occurred. For files
-// detailed data is returned.
-// Usage of watcher_trigger requires:
-// - trigger implementation,
-// - encode func,
-// - not2nat, nat2not maps.
-// Required manual operations on filesystem can lead to loss of precision.
-
-package notify
-
-import (
- "os"
- "path/filepath"
- "strings"
- "sync"
- "syscall"
-)
-
-// trigger is to be implemented by platform implementation like FEN or kqueue.
-type trigger interface {
- // Close closes watcher's main native file descriptor.
- Close() error
- // Stop waiting for new events.
- Stop() error
- // Create new instance of watched.
- NewWatched(string, os.FileInfo) (*watched, error)
- // Record internally new *watched instance.
- Record(*watched)
- // Del removes internal copy of *watched instance.
- Del(*watched)
- // Watched returns *watched instance and native events for native type.
- Watched(interface{}) (*watched, int64, error)
- // Init initializes native watcher call.
- Init() error
- // Watch starts watching provided file/dir.
- Watch(os.FileInfo, *watched, int64) error
- // Unwatch stops watching provided file/dir.
- Unwatch(*watched) error
- // Wait for new events.
- Wait() (interface{}, error)
- // IsStop checks if Wait finished because of request watcher's stop.
- IsStop(n interface{}, err error) bool
-}
-
-// encode Event to native representation. Implementation is to be provided by
-// platform specific implementation.
-var encode func(Event, bool) int64
-
-var (
- // nat2not matches native events to notify's ones. To be initialized by
- // platform dependent implementation.
- nat2not map[Event]Event
- // not2nat matches notify's events to native ones. To be initialized by
- // platform dependent implementation.
- not2nat map[Event]Event
-)
-
-// trg is a main structure implementing watcher.
-type trg struct {
- sync.Mutex
- // s is a channel used to stop monitoring.
- s chan struct{}
- // c is a channel used to pass events further.
- c chan<- EventInfo
- // pthLkp is a data structure mapping file names with data about watching
- // represented by them files/directories.
- pthLkp map[string]*watched
- // t is a platform dependent implementation of trigger.
- t trigger
-}
-
-// newWatcher returns new watcher's implementation.
-func newWatcher(c chan<- EventInfo) watcher {
- t := &trg{
- s: make(chan struct{}, 1),
- pthLkp: make(map[string]*watched, 0),
- c: c,
- }
- t.t = newTrigger(t.pthLkp)
- if err := t.t.Init(); err != nil {
- panic(err)
- }
- go t.monitor()
- return t
-}
-
-// Close implements watcher.
-func (t *trg) Close() (err error) {
- t.Lock()
- if err = t.t.Stop(); err != nil {
- t.Unlock()
- return
- }
- <-t.s
- var e error
- for _, w := range t.pthLkp {
- if e = t.unwatch(w.p, w.fi); e != nil {
- dbgprintf("trg: unwatch %q failed: %q\n", w.p, e)
- err = nonil(err, e)
- }
- }
- if e = t.t.Close(); e != nil {
- dbgprintf("trg: closing native watch failed: %q\n", e)
- err = nonil(err, e)
- }
- t.Unlock()
- return
-}
-
-// send reported events one by one through chan.
-func (t *trg) send(evn []event) {
- for i := range evn {
- t.c <- &evn[i]
- }
-}
-
-// singlewatch starts to watch given p file/directory.
-func (t *trg) singlewatch(p string, e Event, direct mode, fi os.FileInfo) (err error) {
- w, ok := t.pthLkp[p]
- if !ok {
- if w, err = t.t.NewWatched(p, fi); err != nil {
- return
- }
- }
- switch direct {
- case dir:
- w.eDir |= e
- case ndir:
- w.eNonDir |= e
- case both:
- w.eDir |= e
- w.eNonDir |= e
- }
- if err = t.t.Watch(fi, w, encode(w.eDir|w.eNonDir, fi.IsDir())); err != nil {
- return
- }
- if !ok {
- t.t.Record(w)
- return nil
- }
- return errAlreadyWatched
-}
-
-// decode converts event received from native to notify.Event
-// representation taking into account requested events (w).
-func decode(o int64, w Event) (e Event) {
- for f, n := range nat2not {
- if o&int64(f) != 0 {
- if w&f != 0 {
- e |= f
- }
- if w&n != 0 {
- e |= n
- }
- }
- }
-
- return
-}
-
-func (t *trg) watch(p string, e Event, fi os.FileInfo) error {
- if err := t.singlewatch(p, e, dir, fi); err != nil {
- if err != errAlreadyWatched {
- return nil
- }
- }
- if fi.IsDir() {
- err := t.walk(p, func(fi os.FileInfo) (err error) {
- if err = t.singlewatch(filepath.Join(p, fi.Name()), e, ndir,
- fi); err != nil {
- if err != errAlreadyWatched {
- return
- }
- }
- return nil
- })
- if err != nil {
- return err
- }
- }
- return nil
-}
-
-// walk runs f func on each file/dir from p directory.
-func (t *trg) walk(p string, fn func(os.FileInfo) error) error {
- fp, err := os.Open(p)
- if err != nil {
- return err
- }
- ls, err := fp.Readdir(0)
- fp.Close()
- if err != nil {
- return err
- }
- for i := range ls {
- if err := fn(ls[i]); err != nil {
- return err
- }
- }
- return nil
-}
-
-func (t *trg) unwatch(p string, fi os.FileInfo) error {
- if fi.IsDir() {
- err := t.walk(p, func(fi os.FileInfo) error {
- err := t.singleunwatch(filepath.Join(p, fi.Name()), ndir)
- if err != errNotWatched {
- return err
- }
- return nil
- })
- if err != nil {
- return err
- }
- }
- return t.singleunwatch(p, dir)
-}
-
-// Watch implements Watcher interface.
-func (t *trg) Watch(p string, e Event) error {
- fi, err := os.Stat(p)
- if err != nil {
- return err
- }
- t.Lock()
- err = t.watch(p, e, fi)
- t.Unlock()
- return err
-}
-
-// Unwatch implements Watcher interface.
-func (t *trg) Unwatch(p string) error {
- fi, err := os.Stat(p)
- if err != nil {
- return err
- }
- t.Lock()
- err = t.unwatch(p, fi)
- t.Unlock()
- return err
-}
-
-// Rewatch implements Watcher interface.
-//
-// TODO(rjeczalik): This is a naive hack. Rewrite might help.
-func (t *trg) Rewatch(p string, _, e Event) error {
- fi, err := os.Stat(p)
- if err != nil {
- return err
- }
- t.Lock()
- if err = t.unwatch(p, fi); err == nil {
- // TODO(rjeczalik): If watch fails then we leave trigger in inconsistent
- // state. Handle? Panic? Native version of rewatch?
- err = t.watch(p, e, fi)
- }
- t.Unlock()
- return nil
-}
-
-func (*trg) file(w *watched, n interface{}, e Event) (evn []event) {
- evn = append(evn, event{w.p, e, w.fi.IsDir(), n})
- return
-}
-
-func (t *trg) dir(w *watched, n interface{}, e, ge Event) (evn []event) {
- // If it's dir and delete we have to send it and continue, because
- // other processing relies on opening (in this case not existing) dir.
- // Events for contents of this dir are reported by native impl.
- // However events for rename must be generated for all monitored files
- // inside of moved directory, because native impl does not report it independently
- // for each file descriptor being moved in result of move action on
- // parent directory.
- if (ge & (not2nat[Rename] | not2nat[Remove])) != 0 {
- // Write is reported also for Remove on directory. Because of that
- // we have to filter it out explicitly.
- evn = append(evn, event{w.p, e & ^Write & ^not2nat[Write], true, n})
- if ge¬2nat[Rename] != 0 {
- for p := range t.pthLkp {
- if strings.HasPrefix(p, w.p+string(os.PathSeparator)) {
- if err := t.singleunwatch(p, both); err != nil && err != errNotWatched &&
- !os.IsNotExist(err) {
- dbgprintf("trg: failed stop watching moved file (%q): %q\n",
- p, err)
- }
- if (w.eDir|w.eNonDir)&(not2nat[Rename]|Rename) != 0 {
- evn = append(evn, event{
- p, (w.eDir | w.eNonDir) & e &^ Write &^ not2nat[Write],
- w.fi.IsDir(), nil,
- })
- }
- }
- }
- }
- t.t.Del(w)
- return
- }
- if (ge & not2nat[Write]) != 0 {
- switch err := t.walk(w.p, func(fi os.FileInfo) error {
- p := filepath.Join(w.p, fi.Name())
- switch err := t.singlewatch(p, w.eDir, ndir, fi); {
- case os.IsNotExist(err) && ((w.eDir & Remove) != 0):
- evn = append(evn, event{p, Remove, fi.IsDir(), n})
- case err == errAlreadyWatched:
- case err != nil:
- dbgprintf("trg: watching %q failed: %q", p, err)
- case (w.eDir & Create) != 0:
- evn = append(evn, event{p, Create, fi.IsDir(), n})
- default:
- }
- return nil
- }); {
- case os.IsNotExist(err):
- return
- case err != nil:
- dbgprintf("trg: dir processing failed: %q", err)
- default:
- }
- }
- return
-}
-
-type mode uint
-
-const (
- dir mode = iota
- ndir
- both
-)
-
-// unwatch stops watching p file/directory.
-func (t *trg) singleunwatch(p string, direct mode) error {
- w, ok := t.pthLkp[p]
- if !ok {
- return errNotWatched
- }
- switch direct {
- case dir:
- w.eDir = 0
- case ndir:
- w.eNonDir = 0
- case both:
- w.eDir, w.eNonDir = 0, 0
- }
- if err := t.t.Unwatch(w); err != nil {
- return err
- }
- if w.eNonDir|w.eDir != 0 {
- mod := dir
- if w.eNonDir == 0 {
- mod = ndir
- }
- if err := t.singlewatch(p, w.eNonDir|w.eDir, mod,
- w.fi); err != nil && err != errAlreadyWatched {
- return err
- }
- } else {
- t.t.Del(w)
- }
- return nil
-}
-
-func (t *trg) monitor() {
- var (
- n interface{}
- err error
- )
- for {
- switch n, err = t.t.Wait(); {
- case err == syscall.EINTR:
- case t.t.IsStop(n, err):
- t.s <- struct{}{}
- return
- case err != nil:
- dbgprintf("trg: failed to read events: %q\n", err)
- default:
- t.send(t.process(n))
- }
- }
-}
-
-// process event returned by native call.
-func (t *trg) process(n interface{}) (evn []event) {
- t.Lock()
- w, ge, err := t.t.Watched(n)
- if err != nil {
- t.Unlock()
- dbgprintf("trg: %v event lookup failed: %q", Event(ge), err)
- return
- }
-
- e := decode(ge, w.eDir|w.eNonDir)
- if ge&int64(not2nat[Remove]|not2nat[Rename]) == 0 {
- switch fi, err := os.Stat(w.p); {
- case err != nil:
- default:
- if err = t.t.Watch(fi, w, encode(w.eDir|w.eNonDir, fi.IsDir())); err != nil {
- dbgprintf("trg: %q is no longer watched: %q", w.p, err)
- t.t.Del(w)
- }
- }
- }
- if e == Event(0) && (!w.fi.IsDir() || (ge&int64(not2nat[Write])) == 0) {
- t.Unlock()
- return
- }
-
- if w.fi.IsDir() {
- evn = append(evn, t.dir(w, n, e, Event(ge))...)
- } else {
- evn = append(evn, t.file(w, n, e)...)
- }
- if Event(ge)&(not2nat[Remove]|not2nat[Rename]) != 0 {
- t.t.Del(w)
- }
- t.Unlock()
- return
-}
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