+++ /dev/null
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build windows
-
-package fsnotify
-
-import (
- "errors"
- "fmt"
- "os"
- "path/filepath"
- "runtime"
- "sync"
- "syscall"
- "unsafe"
-)
-
-// Watcher watches a set of files, delivering events to a channel.
-type Watcher struct {
- Events chan Event
- Errors chan error
- isClosed bool // Set to true when Close() is first called
- mu sync.Mutex // Map access
- port syscall.Handle // Handle to completion port
- watches watchMap // Map of watches (key: i-number)
- input chan *input // Inputs to the reader are sent on this channel
- quit chan chan<- error
-}
-
-// NewWatcher establishes a new watcher with the underlying OS and begins waiting for events.
-func NewWatcher() (*Watcher, error) {
- port, e := syscall.CreateIoCompletionPort(syscall.InvalidHandle, 0, 0, 0)
- if e != nil {
- return nil, os.NewSyscallError("CreateIoCompletionPort", e)
- }
- w := &Watcher{
- port: port,
- watches: make(watchMap),
- input: make(chan *input, 1),
- Events: make(chan Event, 50),
- Errors: make(chan error),
- quit: make(chan chan<- error, 1),
- }
- go w.readEvents()
- return w, nil
-}
-
-// Close removes all watches and closes the events channel.
-func (w *Watcher) Close() error {
- if w.isClosed {
- return nil
- }
- w.isClosed = true
-
- // Send "quit" message to the reader goroutine
- ch := make(chan error)
- w.quit <- ch
- if err := w.wakeupReader(); err != nil {
- return err
- }
- return <-ch
-}
-
-// Add starts watching the named file or directory (non-recursively).
-func (w *Watcher) Add(name string) error {
- if w.isClosed {
- return errors.New("watcher already closed")
- }
- in := &input{
- op: opAddWatch,
- path: filepath.Clean(name),
- flags: sysFSALLEVENTS,
- reply: make(chan error),
- }
- w.input <- in
- if err := w.wakeupReader(); err != nil {
- return err
- }
- return <-in.reply
-}
-
-// Remove stops watching the the named file or directory (non-recursively).
-func (w *Watcher) Remove(name string) error {
- in := &input{
- op: opRemoveWatch,
- path: filepath.Clean(name),
- reply: make(chan error),
- }
- w.input <- in
- if err := w.wakeupReader(); err != nil {
- return err
- }
- return <-in.reply
-}
-
-const (
- // Options for AddWatch
- sysFSONESHOT = 0x80000000
- sysFSONLYDIR = 0x1000000
-
- // Events
- sysFSACCESS = 0x1
- sysFSALLEVENTS = 0xfff
- sysFSATTRIB = 0x4
- sysFSCLOSE = 0x18
- sysFSCREATE = 0x100
- sysFSDELETE = 0x200
- sysFSDELETESELF = 0x400
- sysFSMODIFY = 0x2
- sysFSMOVE = 0xc0
- sysFSMOVEDFROM = 0x40
- sysFSMOVEDTO = 0x80
- sysFSMOVESELF = 0x800
-
- // Special events
- sysFSIGNORED = 0x8000
- sysFSQOVERFLOW = 0x4000
-)
-
-func newEvent(name string, mask uint32) Event {
- e := Event{Name: name}
- if mask&sysFSCREATE == sysFSCREATE || mask&sysFSMOVEDTO == sysFSMOVEDTO {
- e.Op |= Create
- }
- if mask&sysFSDELETE == sysFSDELETE || mask&sysFSDELETESELF == sysFSDELETESELF {
- e.Op |= Remove
- }
- if mask&sysFSMODIFY == sysFSMODIFY {
- e.Op |= Write
- }
- if mask&sysFSMOVE == sysFSMOVE || mask&sysFSMOVESELF == sysFSMOVESELF || mask&sysFSMOVEDFROM == sysFSMOVEDFROM {
- e.Op |= Rename
- }
- if mask&sysFSATTRIB == sysFSATTRIB {
- e.Op |= Chmod
- }
- return e
-}
-
-const (
- opAddWatch = iota
- opRemoveWatch
-)
-
-const (
- provisional uint64 = 1 << (32 + iota)
-)
-
-type input struct {
- op int
- path string
- flags uint32
- reply chan error
-}
-
-type inode struct {
- handle syscall.Handle
- volume uint32
- index uint64
-}
-
-type watch struct {
- ov syscall.Overlapped
- ino *inode // i-number
- path string // Directory path
- mask uint64 // Directory itself is being watched with these notify flags
- names map[string]uint64 // Map of names being watched and their notify flags
- rename string // Remembers the old name while renaming a file
- buf [4096]byte
-}
-
-type indexMap map[uint64]*watch
-type watchMap map[uint32]indexMap
-
-func (w *Watcher) wakeupReader() error {
- e := syscall.PostQueuedCompletionStatus(w.port, 0, 0, nil)
- if e != nil {
- return os.NewSyscallError("PostQueuedCompletionStatus", e)
- }
- return nil
-}
-
-func getDir(pathname string) (dir string, err error) {
- attr, e := syscall.GetFileAttributes(syscall.StringToUTF16Ptr(pathname))
- if e != nil {
- return "", os.NewSyscallError("GetFileAttributes", e)
- }
- if attr&syscall.FILE_ATTRIBUTE_DIRECTORY != 0 {
- dir = pathname
- } else {
- dir, _ = filepath.Split(pathname)
- dir = filepath.Clean(dir)
- }
- return
-}
-
-func getIno(path string) (ino *inode, err error) {
- h, e := syscall.CreateFile(syscall.StringToUTF16Ptr(path),
- syscall.FILE_LIST_DIRECTORY,
- syscall.FILE_SHARE_READ|syscall.FILE_SHARE_WRITE|syscall.FILE_SHARE_DELETE,
- nil, syscall.OPEN_EXISTING,
- syscall.FILE_FLAG_BACKUP_SEMANTICS|syscall.FILE_FLAG_OVERLAPPED, 0)
- if e != nil {
- return nil, os.NewSyscallError("CreateFile", e)
- }
- var fi syscall.ByHandleFileInformation
- if e = syscall.GetFileInformationByHandle(h, &fi); e != nil {
- syscall.CloseHandle(h)
- return nil, os.NewSyscallError("GetFileInformationByHandle", e)
- }
- ino = &inode{
- handle: h,
- volume: fi.VolumeSerialNumber,
- index: uint64(fi.FileIndexHigh)<<32 | uint64(fi.FileIndexLow),
- }
- return ino, nil
-}
-
-// Must run within the I/O thread.
-func (m watchMap) get(ino *inode) *watch {
- if i := m[ino.volume]; i != nil {
- return i[ino.index]
- }
- return nil
-}
-
-// Must run within the I/O thread.
-func (m watchMap) set(ino *inode, watch *watch) {
- i := m[ino.volume]
- if i == nil {
- i = make(indexMap)
- m[ino.volume] = i
- }
- i[ino.index] = watch
-}
-
-// Must run within the I/O thread.
-func (w *Watcher) addWatch(pathname string, flags uint64) error {
- dir, err := getDir(pathname)
- if err != nil {
- return err
- }
- if flags&sysFSONLYDIR != 0 && pathname != dir {
- return nil
- }
- ino, err := getIno(dir)
- if err != nil {
- return err
- }
- w.mu.Lock()
- watchEntry := w.watches.get(ino)
- w.mu.Unlock()
- if watchEntry == nil {
- if _, e := syscall.CreateIoCompletionPort(ino.handle, w.port, 0, 0); e != nil {
- syscall.CloseHandle(ino.handle)
- return os.NewSyscallError("CreateIoCompletionPort", e)
- }
- watchEntry = &watch{
- ino: ino,
- path: dir,
- names: make(map[string]uint64),
- }
- w.mu.Lock()
- w.watches.set(ino, watchEntry)
- w.mu.Unlock()
- flags |= provisional
- } else {
- syscall.CloseHandle(ino.handle)
- }
- if pathname == dir {
- watchEntry.mask |= flags
- } else {
- watchEntry.names[filepath.Base(pathname)] |= flags
- }
- if err = w.startRead(watchEntry); err != nil {
- return err
- }
- if pathname == dir {
- watchEntry.mask &= ^provisional
- } else {
- watchEntry.names[filepath.Base(pathname)] &= ^provisional
- }
- return nil
-}
-
-// Must run within the I/O thread.
-func (w *Watcher) remWatch(pathname string) error {
- dir, err := getDir(pathname)
- if err != nil {
- return err
- }
- ino, err := getIno(dir)
- if err != nil {
- return err
- }
- w.mu.Lock()
- watch := w.watches.get(ino)
- w.mu.Unlock()
- if watch == nil {
- return fmt.Errorf("can't remove non-existent watch for: %s", pathname)
- }
- if pathname == dir {
- w.sendEvent(watch.path, watch.mask&sysFSIGNORED)
- watch.mask = 0
- } else {
- name := filepath.Base(pathname)
- w.sendEvent(filepath.Join(watch.path, name), watch.names[name]&sysFSIGNORED)
- delete(watch.names, name)
- }
- return w.startRead(watch)
-}
-
-// Must run within the I/O thread.
-func (w *Watcher) deleteWatch(watch *watch) {
- for name, mask := range watch.names {
- if mask&provisional == 0 {
- w.sendEvent(filepath.Join(watch.path, name), mask&sysFSIGNORED)
- }
- delete(watch.names, name)
- }
- if watch.mask != 0 {
- if watch.mask&provisional == 0 {
- w.sendEvent(watch.path, watch.mask&sysFSIGNORED)
- }
- watch.mask = 0
- }
-}
-
-// Must run within the I/O thread.
-func (w *Watcher) startRead(watch *watch) error {
- if e := syscall.CancelIo(watch.ino.handle); e != nil {
- w.Errors <- os.NewSyscallError("CancelIo", e)
- w.deleteWatch(watch)
- }
- mask := toWindowsFlags(watch.mask)
- for _, m := range watch.names {
- mask |= toWindowsFlags(m)
- }
- if mask == 0 {
- if e := syscall.CloseHandle(watch.ino.handle); e != nil {
- w.Errors <- os.NewSyscallError("CloseHandle", e)
- }
- w.mu.Lock()
- delete(w.watches[watch.ino.volume], watch.ino.index)
- w.mu.Unlock()
- return nil
- }
- e := syscall.ReadDirectoryChanges(watch.ino.handle, &watch.buf[0],
- uint32(unsafe.Sizeof(watch.buf)), false, mask, nil, &watch.ov, 0)
- if e != nil {
- err := os.NewSyscallError("ReadDirectoryChanges", e)
- if e == syscall.ERROR_ACCESS_DENIED && watch.mask&provisional == 0 {
- // Watched directory was probably removed
- if w.sendEvent(watch.path, watch.mask&sysFSDELETESELF) {
- if watch.mask&sysFSONESHOT != 0 {
- watch.mask = 0
- }
- }
- err = nil
- }
- w.deleteWatch(watch)
- w.startRead(watch)
- return err
- }
- return nil
-}
-
-// readEvents reads from the I/O completion port, converts the
-// received events into Event objects and sends them via the Events channel.
-// Entry point to the I/O thread.
-func (w *Watcher) readEvents() {
- var (
- n, key uint32
- ov *syscall.Overlapped
- )
- runtime.LockOSThread()
-
- for {
- e := syscall.GetQueuedCompletionStatus(w.port, &n, &key, &ov, syscall.INFINITE)
- watch := (*watch)(unsafe.Pointer(ov))
-
- if watch == nil {
- select {
- case ch := <-w.quit:
- w.mu.Lock()
- var indexes []indexMap
- for _, index := range w.watches {
- indexes = append(indexes, index)
- }
- w.mu.Unlock()
- for _, index := range indexes {
- for _, watch := range index {
- w.deleteWatch(watch)
- w.startRead(watch)
- }
- }
- var err error
- if e := syscall.CloseHandle(w.port); e != nil {
- err = os.NewSyscallError("CloseHandle", e)
- }
- close(w.Events)
- close(w.Errors)
- ch <- err
- return
- case in := <-w.input:
- switch in.op {
- case opAddWatch:
- in.reply <- w.addWatch(in.path, uint64(in.flags))
- case opRemoveWatch:
- in.reply <- w.remWatch(in.path)
- }
- default:
- }
- continue
- }
-
- switch e {
- case syscall.ERROR_MORE_DATA:
- if watch == nil {
- w.Errors <- errors.New("ERROR_MORE_DATA has unexpectedly null lpOverlapped buffer")
- } else {
- // The i/o succeeded but the buffer is full.
- // In theory we should be building up a full packet.
- // In practice we can get away with just carrying on.
- n = uint32(unsafe.Sizeof(watch.buf))
- }
- case syscall.ERROR_ACCESS_DENIED:
- // Watched directory was probably removed
- w.sendEvent(watch.path, watch.mask&sysFSDELETESELF)
- w.deleteWatch(watch)
- w.startRead(watch)
- continue
- case syscall.ERROR_OPERATION_ABORTED:
- // CancelIo was called on this handle
- continue
- default:
- w.Errors <- os.NewSyscallError("GetQueuedCompletionPort", e)
- continue
- case nil:
- }
-
- var offset uint32
- for {
- if n == 0 {
- w.Events <- newEvent("", sysFSQOVERFLOW)
- w.Errors <- errors.New("short read in readEvents()")
- break
- }
-
- // Point "raw" to the event in the buffer
- raw := (*syscall.FileNotifyInformation)(unsafe.Pointer(&watch.buf[offset]))
- buf := (*[syscall.MAX_PATH]uint16)(unsafe.Pointer(&raw.FileName))
- name := syscall.UTF16ToString(buf[:raw.FileNameLength/2])
- fullname := filepath.Join(watch.path, name)
-
- var mask uint64
- switch raw.Action {
- case syscall.FILE_ACTION_REMOVED:
- mask = sysFSDELETESELF
- case syscall.FILE_ACTION_MODIFIED:
- mask = sysFSMODIFY
- case syscall.FILE_ACTION_RENAMED_OLD_NAME:
- watch.rename = name
- case syscall.FILE_ACTION_RENAMED_NEW_NAME:
- if watch.names[watch.rename] != 0 {
- watch.names[name] |= watch.names[watch.rename]
- delete(watch.names, watch.rename)
- mask = sysFSMOVESELF
- }
- }
-
- sendNameEvent := func() {
- if w.sendEvent(fullname, watch.names[name]&mask) {
- if watch.names[name]&sysFSONESHOT != 0 {
- delete(watch.names, name)
- }
- }
- }
- if raw.Action != syscall.FILE_ACTION_RENAMED_NEW_NAME {
- sendNameEvent()
- }
- if raw.Action == syscall.FILE_ACTION_REMOVED {
- w.sendEvent(fullname, watch.names[name]&sysFSIGNORED)
- delete(watch.names, name)
- }
- if w.sendEvent(fullname, watch.mask&toFSnotifyFlags(raw.Action)) {
- if watch.mask&sysFSONESHOT != 0 {
- watch.mask = 0
- }
- }
- if raw.Action == syscall.FILE_ACTION_RENAMED_NEW_NAME {
- fullname = filepath.Join(watch.path, watch.rename)
- sendNameEvent()
- }
-
- // Move to the next event in the buffer
- if raw.NextEntryOffset == 0 {
- break
- }
- offset += raw.NextEntryOffset
-
- // Error!
- if offset >= n {
- w.Errors <- errors.New("Windows system assumed buffer larger than it is, events have likely been missed.")
- break
- }
- }
-
- if err := w.startRead(watch); err != nil {
- w.Errors <- err
- }
- }
-}
-
-func (w *Watcher) sendEvent(name string, mask uint64) bool {
- if mask == 0 {
- return false
- }
- event := newEvent(name, uint32(mask))
- select {
- case ch := <-w.quit:
- w.quit <- ch
- case w.Events <- event:
- }
- return true
-}
-
-func toWindowsFlags(mask uint64) uint32 {
- var m uint32
- if mask&sysFSACCESS != 0 {
- m |= syscall.FILE_NOTIFY_CHANGE_LAST_ACCESS
- }
- if mask&sysFSMODIFY != 0 {
- m |= syscall.FILE_NOTIFY_CHANGE_LAST_WRITE
- }
- if mask&sysFSATTRIB != 0 {
- m |= syscall.FILE_NOTIFY_CHANGE_ATTRIBUTES
- }
- if mask&(sysFSMOVE|sysFSCREATE|sysFSDELETE) != 0 {
- m |= syscall.FILE_NOTIFY_CHANGE_FILE_NAME | syscall.FILE_NOTIFY_CHANGE_DIR_NAME
- }
- return m
-}
-
-func toFSnotifyFlags(action uint32) uint64 {
- switch action {
- case syscall.FILE_ACTION_ADDED:
- return sysFSCREATE
- case syscall.FILE_ACTION_REMOVED:
- return sysFSDELETE
- case syscall.FILE_ACTION_MODIFIED:
- return sysFSMODIFY
- case syscall.FILE_ACTION_RENAMED_OLD_NAME:
- return sysFSMOVEDFROM
- case syscall.FILE_ACTION_RENAMED_NEW_NAME:
- return sysFSMOVEDTO
- }
- return 0
-}
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