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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/gopkg.in/fsnotify.v1/windows.go | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/gopkg.in/fsnotify.v1/windows.go')
-rw-r--r-- | vendor/gopkg.in/fsnotify.v1/windows.go | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/vendor/gopkg.in/fsnotify.v1/windows.go b/vendor/gopkg.in/fsnotify.v1/windows.go new file mode 100644 index 000000000..09436f31d --- /dev/null +++ b/vendor/gopkg.in/fsnotify.v1/windows.go @@ -0,0 +1,561 @@ +// 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 +} |