1 files changed, 438 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/rjeczalik/notify/watcher_trigger.go b/Godeps/_workspace/src/github.com/rjeczalik/notify/watcher_trigger.go
new file mode 100644
index 000000000..f25a6fcbf
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/rjeczalik/notify/watcher_trigger.go
@@ -0,0 +1,438 @@
+// 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) 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
+	}
+	var ee int64
+	// Native Write event is added to wait for Create events (Write event on
+	// directory triggers it's rescan).
+	if e&Create != 0 && fi.IsDir() {
+		ee = int64(not2nat[Write])
+	}
+	if err = t.t.Watch(fi, w, encode(w.eDir|w.eNonDir)|ee); 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 dirLiczba dostępnych dni urlopowych: 0ectory.
+	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&not2nat[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 port_get 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))); err != nil {
+				dbgprintf("trg: %q is no longer watched: %q", w.p, err)
+				t.t.Del(w)
+			}
+		}
+	}
+	if e == Event(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
+}