.

wcfs/vendor/github.com/fsnotify/fsnotify/windows.go

-// 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
-}

wcfs/vendor/lab.nexedi.com/kirr/go123/xcontainer/list/list.go

-// Copyright (C) 2017-2019  Nexedi SA and Contributors.
-//                          Kirill Smelkov <kirr@nexedi.com>
-//
-// This program is free software: you can Use, Study, Modify and Redistribute
-// it under the terms of the GNU General Public License version 3, or (at your
-// option) any later version, as published by the Free Software Foundation.
-//
-// You can also Link and Combine this program with other software covered by
-// the terms of any of the Free Software licenses or any of the Open Source
-// Initiative approved licenses and Convey the resulting work. Corresponding
-// source of such a combination shall include the source code for all other
-// software used.
-//
-// This program is distributed WITHOUT ANY WARRANTY; without even the implied
-// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-//
-// See COPYING file for full licensing terms.
-// See https://www.nexedi.com/licensing for rationale and options.
-
-// Package list provides intrusive double-linked lists.
-//
-// Go standard library has container/list package which already provides
-// double-linked lists. However in that implementation list itself is kept
-// separate from data structures representing elements. This package provides
-// alternative approach where elements embed necessary list heads which is
-// sometimes more convenient, for example when one wants to move a list
-// element in O(1) starting from pointer to just its data.
-//
-// TODO doc how to get to container of list head via unsafe.OffsetOf.
-package list
-
-// Head is a list head entry for an element in an intrusive doubly-linked list.
-//
-// Zero HEAD value is NOT valid - always call Init() to initialize a head
-// before using it.
-type Head struct {
-	next, prev *Head
-}
-
-func (h *Head) Next() *Head { return h.next }
-func (h *Head) Prev() *Head { return h.prev }
-
-// Init initializes a head making it point to itself via .next and .prev .
-func (h *Head) Init() {
-	h.next = h
-	h.prev = h
-}
-
-// Delete deletes h from its list.
-func (h *Head) Delete() {
-	h.next.prev = h.prev
-	h.prev.next = h.next
-	h.Init()
-}
-
-// MoveBefore moves a to be before b.
-//
-// XXX ok to move if a was not previously on the list?
-func (a *Head) MoveBefore(b *Head) {
-	a.Delete()
-
-	a.next = b
-	a.prev = b.prev
-	b.prev = a
-	a.prev.next = a
-}