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@@ -1,205 +0,0 @@
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-package filenotify
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-
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-import (
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- "errors"
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- "fmt"
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- "os"
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- "sync"
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- "time"
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-
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- "github.com/Sirupsen/logrus"
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-
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- "gopkg.in/fsnotify.v1"
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-)
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-
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-var (
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- // errPollerClosed is returned when the poller is closed
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- errPollerClosed = errors.New("poller is closed")
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- // errNoSuchPoller is returned when trying to remove a watch that doesn't exist
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- errNoSuchWatch = errors.New("poller does not exist")
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-)
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-
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-// watchWaitTime is the time to wait between file poll loops
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-const watchWaitTime = 200 * time.Millisecond
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-
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-// filePoller is used to poll files for changes, especially in cases where fsnotify
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-// can't be run (e.g. when inotify handles are exhausted)
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-// filePoller satisfies the FileWatcher interface
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-type filePoller struct {
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- // watches is the list of files currently being polled, close the associated channel to stop the watch
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- watches map[string]chan struct{}
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- // events is the channel to listen to for watch events
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- events chan fsnotify.Event
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- // errors is the channel to listen to for watch errors
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- errors chan error
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- // mu locks the poller for modification
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- mu sync.Mutex
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- // closed is used to specify when the poller has already closed
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- closed bool
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-}
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-
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-// Add adds a filename to the list of watches
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-// once added the file is polled for changes in a separate goroutine
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-func (w *filePoller) Add(name string) error {
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- w.mu.Lock()
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- defer w.mu.Unlock()
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-
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- if w.closed == true {
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- return errPollerClosed
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- }
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-
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- f, err := os.Open(name)
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- if err != nil {
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- return err
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- }
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- fi, err := os.Stat(name)
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- if err != nil {
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- return err
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- }
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-
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- if w.watches == nil {
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- w.watches = make(map[string]chan struct{})
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- }
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- if _, exists := w.watches[name]; exists {
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- return fmt.Errorf("watch exists")
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- }
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- chClose := make(chan struct{})
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- w.watches[name] = chClose
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-
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- go w.watch(f, fi, chClose)
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- return nil
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-}
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-
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-// Remove stops and removes watch with the specified name
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-func (w *filePoller) Remove(name string) error {
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- w.mu.Lock()
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- defer w.mu.Unlock()
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- return w.remove(name)
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-}
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-
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-func (w *filePoller) remove(name string) error {
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- if w.closed == true {
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- return errPollerClosed
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- }
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-
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- chClose, exists := w.watches[name]
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- if !exists {
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- return errNoSuchWatch
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- }
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- close(chClose)
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- delete(w.watches, name)
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- return nil
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-}
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-
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-// Events returns the event channel
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-// This is used for notifications on events about watched files
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-func (w *filePoller) Events() <-chan fsnotify.Event {
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- return w.events
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-}
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-
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-// Errors returns the errors channel
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-// This is used for notifications about errors on watched files
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-func (w *filePoller) Errors() <-chan error {
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- return w.errors
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-}
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-
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-// Close closes the poller
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-// All watches are stopped, removed, and the poller cannot be added to
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-func (w *filePoller) Close() error {
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- w.mu.Lock()
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- defer w.mu.Unlock()
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-
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- if w.closed {
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- return nil
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- }
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-
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- w.closed = true
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- for name := range w.watches {
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- w.remove(name)
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- delete(w.watches, name)
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- }
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- close(w.events)
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- close(w.errors)
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- return nil
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-}
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-
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-// sendEvent publishes the specified event to the events channel
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-func (w *filePoller) sendEvent(e fsnotify.Event, chClose <-chan struct{}) error {
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- select {
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- case w.events <- e:
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- case <-chClose:
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- return fmt.Errorf("closed")
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- }
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- return nil
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-}
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-
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-// sendErr publishes the specified error to the errors channel
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-func (w *filePoller) sendErr(e error, chClose <-chan struct{}) error {
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- select {
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- case w.errors <- e:
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- case <-chClose:
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- return fmt.Errorf("closed")
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- }
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- return nil
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-}
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-
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-// watch is responsible for polling the specified file for changes
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-// upon finding changes to a file or errors, sendEvent/sendErr is called
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-func (w *filePoller) watch(f *os.File, lastFi os.FileInfo, chClose chan struct{}) {
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- for {
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- time.Sleep(watchWaitTime)
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- select {
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- case <-chClose:
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- logrus.Debugf("watch for %s closed", f.Name())
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- return
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- default:
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- }
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-
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- fi, err := os.Stat(f.Name())
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- if err != nil {
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- // if we got an error here and lastFi is not set, we can presume that nothing has changed
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- // This should be safe since before `watch()` is called, a stat is performed, there is any error `watch` is not called
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- if lastFi == nil {
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- continue
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- }
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- // If it doesn't exist at this point, it must have been removed
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- // no need to send the error here since this is a valid operation
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- if os.IsNotExist(err) {
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- if err := w.sendEvent(fsnotify.Event{Op: fsnotify.Remove, Name: f.Name()}, chClose); err != nil {
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- return
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- }
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- lastFi = nil
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- continue
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- }
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- // at this point, send the error
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- if err := w.sendErr(err, chClose); err != nil {
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- return
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- }
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- continue
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- }
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-
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- if lastFi == nil {
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- if err := w.sendEvent(fsnotify.Event{Op: fsnotify.Create, Name: fi.Name()}, chClose); err != nil {
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- return
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- }
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- lastFi = fi
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- continue
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- }
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-
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- if fi.Mode() != lastFi.Mode() {
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- if err := w.sendEvent(fsnotify.Event{Op: fsnotify.Chmod, Name: fi.Name()}, chClose); err != nil {
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- return
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- }
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- lastFi = fi
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- continue
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- }
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-
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- if fi.ModTime() != lastFi.ModTime() || fi.Size() != lastFi.Size() {
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- if err := w.sendEvent(fsnotify.Event{Op: fsnotify.Write, Name: fi.Name()}, chClose); err != nil {
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- return
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- }
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- lastFi = fi
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- continue
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- }
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- }
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-}
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