Golang syscall.CreateFileMapping函數代碼示例

// mmap memory maps a DB's data file.
// Based on: https://github.com/edsrzf/mmap-go
func mmap(db *DB, sz int) error {
	if !db.readOnly {
		// Truncate the database to the size of the mmap.
		if err := db.file.Truncate(int64(sz)); err != nil {
			return fmt.Errorf("truncate: %s", err)
		}
	}

	// Open a file mapping handle.
	sizelo := uint32(sz >> 32)
	sizehi := uint32(sz) & 0xffffffff
	h, errno := syscall.CreateFileMapping(syscall.Handle(db.file.Fd()), nil, syscall.PAGE_READONLY, sizelo, sizehi, nil)
	if h == 0 {
		return os.NewSyscallError("CreateFileMapping", errno)
	}

	// Create the memory map.
	addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, uintptr(sz))
	if addr == 0 {
		return os.NewSyscallError("MapViewOfFile", errno)
	}

	// Close mapping handle.
	if err := syscall.CloseHandle(syscall.Handle(h)); err != nil {
		return os.NewSyscallError("CloseHandle", err)
	}

	// Convert to a byte array.
	db.data = ((*[maxMapSize]byte)(unsafe.Pointer(addr)))
	db.datasz = sz

	return nil
}

// Implement mmap for windows
func map_file(file *os.File, offset, size int) ([]byte, error) {

	// create the mapping handle
	h, err := syscall.CreateFileMapping(syscall.Handle(file.Fd()), nil, syscall.PAGE_READONLY, 0, uint32(size), nil)
	if err != nil {
		return nil, err
	}

	// perform the file map operation
	addr, err := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, uint32(offset>>32), uint32(offset), uintptr(size))
	if err != nil {
		return nil, err
	}

	// store the mapping handle
	win_mapper_mutex.Lock()
	win_mapper_handle[addr] = h
	win_mapper_mutex.Unlock()

	// Slice memory layout
	sl := reflect.SliceHeader{Data: addr, Len: size, Cap: size}

	// Use unsafe to turn sl into a []byte.
	bp := *(*[]byte)(unsafe.Pointer(&sl))

	return bp, err
}

func mmap(hfile uintptr, off int64, len int) (uintptr, error) {
	flProtect := uint32(syscall.PAGE_READONLY)
	dwDesiredAccess := uint32(syscall.FILE_MAP_READ)

	flProtect = syscall.PAGE_READWRITE
	dwDesiredAccess = syscall.FILE_MAP_WRITE

	// The maximum size is the area of the file, starting from 0,
	// that we wish to allow to be mappable. It is the sum of
	// the length the user requested, plus the offset where that length
	// is starting from. This does not map the data into memory.
	maxSizeHigh := uint32((off + int64(len)) >> 32)
	maxSizeLow := uint32((off + int64(len)) & 0xFFFFFFFF)
	// TODO: Do we need to set some security attributes? It might help portability.
	h, errno := syscall.CreateFileMapping(syscall.Handle(hfile), nil, flProtect, maxSizeHigh, maxSizeLow, nil)
	if h == 0 {
		return 0, os.NewSyscallError("CreateFileMapping", errno)
	}

	// Actually map a view of the data into memory. The view's size
	// is the length the user requested.
	fileOffsetHigh := uint32(off >> 32)
	fileOffsetLow := uint32(off & 0xFFFFFFFF)
	addr, errno := syscall.MapViewOfFile(h, dwDesiredAccess, fileOffsetHigh, fileOffsetLow, uintptr(len))
	if addr == 0 {
		return 0, os.NewSyscallError("MapViewOfFile", errno)
	}

	return addr, nil
}

func mmap(f *os.File, offset int64, length int) (out []byte, err error) {
	// Open a file mapping handle.
	sizelo := uint32(length >> 32)
	sizehi := uint32(length) & 0xffffffff

	sharedHandle, errno := openSharedFile(f)
	if errno != nil {
		return nil, os.NewSyscallError("CreateFile", errno)
	}

	h, errno := syscall.CreateFileMapping(syscall.Handle(sharedHandle.Fd()), nil, syscall.PAGE_READONLY, sizelo, sizehi, nil)
	if h == 0 {
		return nil, os.NewSyscallError("CreateFileMapping", errno)
	}

	// Create the memory map.
	addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, uintptr(length))
	if addr == 0 {
		return nil, os.NewSyscallError("MapViewOfFile", errno)
	}

	handleLock.Lock()
	handleMap[addr] = h
	fileMap[addr] = sharedHandle
	handleLock.Unlock()

	// Convert to a byte array.
	hdr := (*reflect.SliceHeader)(unsafe.Pointer(&out))
	hdr.Data = uintptr(unsafe.Pointer(addr))
	hdr.Len = length
	hdr.Cap = length

	return
}

func mmapFile(f *os.File) mmapData {
	st, err := f.Stat()
	if err != nil {
		log.Fatal(err)
	}
	size := st.Size()
	if int64(int(size+4095)) != size+4095 {
		log.Fatalf("%s: too large for mmap", f.Name())
	}
	if size == 0 {
		return mmapData{f, nil, nil}
	}
	h, err := syscall.CreateFileMapping(syscall.Handle(f.Fd()), nil, syscall.PAGE_READONLY, uint32(size>>32), uint32(size), nil)
	if err != nil {
		log.Fatalf("CreateFileMapping %s: %v", f.Name(), err)
	}
	defer syscall.CloseHandle(syscall.Handle(h))

	addr, err := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, 0)
	if err != nil {
		log.Fatalf("MapViewOfFile %s: %v", f.Name(), err)
	}

	data := (*[1 << 30]byte)(unsafe.Pointer(addr))
	return mmapData{f, data[:size], data[:]}
}

func Open(filename string) (mf *memfile, err error) {
	f, err := os.Open(filename)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	fs, err := f.Stat()
	if err != nil {
		return nil, err
	}
	fsize := fs.Size()
	fmap, err := syscall.CreateFileMapping(syscall.Handle(f.Fd()), nil, syscall.PAGE_READONLY, 0, uint32(fsize), nil)
	if err != nil {
		return nil, err
	}
	defer syscall.CloseHandle(fmap)
	ptr, err := syscall.MapViewOfFile(fmap, syscall.FILE_MAP_READ, 0, 0, uintptr(fsize))
	if err != nil {
		return nil, err
	}
	defer func() {
		if recover() != nil {
			mf = nil
			err = errors.New("Failed option a file")
		}
	}()
	return &memfile{ptr, fsize, (*[1 << 30]byte)(unsafe.Pointer(ptr))[:fsize]}, nil
}

func mmap(fd uintptr, off int64, l, inprot int) (sli []byte, err error) {
	flProtect := uint32(syscall.PAGE_READONLY)
	dwDesiredAccess := uint32(syscall.FILE_MAP_READ)
	switch {
	case inprot&WRITE != 0:
		flProtect = syscall.PAGE_READWRITE
		dwDesiredAccess = syscall.FILE_MAP_WRITE
	case inprot&RDWR != 0:
		flProtect = syscall.PAGE_READWRITE
		dwDesiredAccess = syscall.FILE_MAP_WRITE
	}
	h, errno := syscall.CreateFileMapping(syscall.Handle(fd), nil, flProtect, 0, uint32(l), nil)
	if h == 0 {
		return nil, os.NewSyscallError("CreateFileMapping", errno)
	}
	addr, errno := syscall.MapViewOfFile(h, dwDesiredAccess, uint32(off>>32), uint32(off&0xFFFFFFFF), uintptr(l))
	if addr == 0 {
		return nil, os.NewSyscallError("MapViewOfFile", errno)
	}
	handleLock.Lock()
	handleMap[addr] = h
	handleLock.Unlock()
	var header = struct {
		d    uintptr
		l, c int
	}{addr, l, l}
	sli = *(*[]byte)(unsafe.Pointer(&header))
	return sli, nil
}

func mmap(len int, prot, flags, hfile uintptr, off int64) ([]byte, error) {
	flProtect := uint32(syscall.PAGE_READONLY)
	dwDesiredAccess := uint32(syscall.FILE_MAP_READ)
	switch {
	case prot&COPY != 0:
		flProtect = syscall.PAGE_WRITECOPY
		dwDesiredAccess = syscall.FILE_MAP_COPY
	case prot&RDWR != 0:
		flProtect = syscall.PAGE_READWRITE
		dwDesiredAccess = syscall.FILE_MAP_WRITE
	}
	if prot&EXEC != 0 {
		flProtect <<= 4
		dwDesiredAccess |= syscall.FILE_MAP_EXECUTE
	}

	// The maximum size is the area of the file, starting from 0,
	// that we wish to allow to be mappable. It is the sum of
	// the length the user requested, plus the offset where that length
	// is starting from. This does not map the data into memory.
	maxSizeHigh := uint32((off + int64(len)) >> 32)
	maxSizeLow := uint32((off + int64(len)) & 0xFFFFFFFF)
	// TODO: Do we need to set some security attributes? It might help portability.
	h, errno := syscall.CreateFileMapping(syscall.Handle(hfile), nil, flProtect, maxSizeHigh, maxSizeLow, nil)
	if h == 0 {
		return nil, os.NewSyscallError("CreateFileMapping", errno)
	}

	// Actually map a view of the data into memory. The view's size
	// is the length the user requested.
	fileOffsetHigh := uint32(off >> 32)
	fileOffsetLow := uint32(off & 0xFFFFFFFF)
	addr, errno := syscall.MapViewOfFile(h, dwDesiredAccess, fileOffsetHigh, fileOffsetLow, uintptr(len))
	if addr == 0 {
		return nil, os.NewSyscallError("MapViewOfFile", errno)
	}
	handleLock.Lock()
	handleMap[addr] = h
	handleLock.Unlock()

	m := MMap{}
	dh := m.header()
	dh.Data = addr
	dh.Len = len
	dh.Cap = dh.Len

	return m, nil
}

func (m *mmap) mapFile() error {
	h, err := syscall.CreateFileMapping(syscall.Handle(m.src.Fd()), nil, syscall.PAGE_READONLY, uint32(m.sz>>32), uint32(m.sz), nil)
	if err != nil {
		return err
	}
	m.handle = uintptr(h) // for later unmapping
	addr, err := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, 0)
	if err != nil {
		return err
	}
	m.buf = []byte{}
	slcHead := (*reflect.SliceHeader)(unsafe.Pointer(&m.buf))
	slcHead.Data = addr
	slcHead.Len = int(m.sz)
	slcHead.Cap = int(m.sz)
	return nil
}

// Open memory-maps the named file for reading.
func Open(filename string) (*ReaderAt, error) {
	f, err := os.Open(filename)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	fi, err := f.Stat()
	if err != nil {
		return nil, err
	}

	size := fi.Size()
	if size == 0 {
		return &ReaderAt{}, nil
	}
	if size < 0 {
		return nil, fmt.Errorf("mmap: file %q has negative size", filename)
	}
	if size != int64(int(size)) {
		return nil, fmt.Errorf("mmap: file %q is too large", filename)
	}

	low, high := uint32(size), uint32(size>>32)
	fmap, err := syscall.CreateFileMapping(syscall.Handle(f.Fd()), nil, syscall.PAGE_READONLY, high, low, nil)
	if err != nil {
		return nil, err
	}
	defer syscall.CloseHandle(fmap)
	ptr, err := syscall.MapViewOfFile(fmap, syscall.FILE_MAP_READ, 0, 0, uintptr(size))
	if err != nil {
		return nil, err
	}
	data := (*[1 << 30]byte)(unsafe.Pointer(ptr))[:size]

	r := &ReaderAt{data: data}
	if debug {
		var p *byte
		if len(data) != 0 {
			p = &data[0]
		}
		println("mmap", r, p)
	}
	runtime.SetFinalizer(r, (*ReaderAt).Close)
	return r, nil
}

func (agent *Pagent) Connect() error {
	var err (error)
	agent.Hwnd, err = FindWindow(syscall.StringToUTF16Ptr("Pageant"), syscall.StringToUTF16Ptr("Pageant"))
	if err != nil {
		return err
	}

	agent.Fmap, err = syscall.CreateFileMapping(syscall.InvalidHandle, nil, syscall.PAGE_READWRITE, 0, 8129, syscall.StringToUTF16Ptr(MAPNAME))
	if err != nil {
		return errors.New("CreateFileMapping failed..")
	}

	agent.SharedMemory, err = syscall.MapViewOfFile(agent.Fmap, syscall.FILE_MAP_WRITE, 0, 0, 0)
	if err != nil {
		return errors.New("Was not able to map agent..")
	}
	agent.Data = (*[MAX_MSG_LEN]byte)(unsafe.Pointer(agent.SharedMemory))
	return nil
}

func createMapping(name string, size int) (*Mapping, []byte) {
	f, err := os.OpenFile(name, os.O_RDWR, 0)
	if err != nil {
		log.Fatalf("failed to open comm file: %v", err)
	}
	defer f.Close()
	mapping, err := syscall.CreateFileMapping(syscall.InvalidHandle, nil, syscall.PAGE_READWRITE, 0, uint32(size), nil)
	if err != nil {
		log.Fatalf("failed to create file mapping: %v", err)
	}
	const FILE_MAP_ALL_ACCESS = 0xF001F
	addr, err := syscall.MapViewOfFile(mapping, FILE_MAP_ALL_ACCESS, 0, 0, uintptr(size))
	if err != nil {
		log.Fatalf("failed to mmap comm file: %v", err)
	}
	hdr := reflect.SliceHeader{addr, size, size}
	mem := *(*[]byte)(unsafe.Pointer(&hdr))
	mem[0] = 1 // test access
	return &Mapping{mapping, addr}, mem
}

func mmap(len int, prot, flags, hfile uintptr, off int64) ([]byte, error) {
	if int(uint32(len)) != len {
		panic("file is too large to map")
	}
	flProtect := uint32(syscall.PAGE_READONLY)
	dwDesiredAccess := uint32(syscall.FILE_MAP_READ)
	switch {
	case prot&COPY != 0:
		flProtect = syscall.PAGE_WRITECOPY
		dwDesiredAccess = syscall.FILE_MAP_COPY
	case prot&RDWR != 0:
		flProtect = syscall.PAGE_READWRITE
		dwDesiredAccess = syscall.FILE_MAP_WRITE
	}
	if prot&EXEC != 0 {
		flProtect <<= 4
		dwDesiredAccess |= syscall.FILE_MAP_EXECUTE
	}

	// TODO: Do we need to set some security attributes? It might help portability.
	h, errno := syscall.CreateFileMapping(syscall.Handle(hfile), nil, flProtect, 0, uint32(len), nil)
	if h == 0 {
		return nil, os.NewSyscallError("CreateFileMapping", errno)
	}

	addr, errno := syscall.MapViewOfFile(h, dwDesiredAccess, uint32(off>>32), uint32(off&0xFFFFFFFF), uintptr(len))
	if addr == 0 {
		return nil, os.NewSyscallError("MapViewOfFile", errno)
	}
	handleLock.Lock()
	handleMap[addr] = h
	handleLock.Unlock()

	m := MMap{}
	dh := m.header()
	dh.Data = addr
	dh.Len = len
	dh.Cap = dh.Len

	return m, nil
}

// Windows mmap always mapes the entire file regardless of the specified length.
func mmap(length int, hfile uintptr) ([]byte, error) {
	h, errno := syscall.CreateFileMapping(syscall.Handle(hfile), nil, syscall.PAGE_READWRITE, 0, 0, nil)
	if h == 0 {
		return nil, os.NewSyscallError("CreateFileMapping", errno)
	}

	addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_WRITE, 0, 0, 0)
	if addr == 0 {
		return nil, os.NewSyscallError("MapViewOfFile", errno)
	}
	handleLock.Lock()
	handleMap[addr] = h
	handleLock.Unlock()

	m := MMap{}
	dh := m.header()
	dh.Data = addr
	dh.Len = length
	dh.Cap = length

	return m, nil
}

// Windows mmap always mapes the entire file regardless of the specified length.
func mmap(length int, prot, flags, hfile uintptr, off int64) ([]byte, error) {
	flProtect := uint32(syscall.PAGE_READONLY)
	dwDesiredAccess := uint32(syscall.FILE_MAP_READ)
	switch {
	case prot&COPY != 0:
		flProtect = syscall.PAGE_WRITECOPY
		dwDesiredAccess = syscall.FILE_MAP_COPY
	case prot&RDWR != 0:
		flProtect = syscall.PAGE_READWRITE
		dwDesiredAccess = syscall.FILE_MAP_WRITE
	}
	if prot&EXEC != 0 {
		flProtect <<= 4
		dwDesiredAccess |= syscall.FILE_MAP_EXECUTE
	}

	h, errno := syscall.CreateFileMapping(syscall.Handle(hfile), nil, flProtect, 0, 0, nil)
	if h == 0 {
		return nil, os.NewSyscallError("CreateFileMapping", errno)
	}

	addr, errno := syscall.MapViewOfFile(h, dwDesiredAccess, uint32(off>>32), uint32(off&0xFFFFFFFF), 0)
	if addr == 0 {
		return nil, os.NewSyscallError("MapViewOfFile", errno)
	}
	handleLock.Lock()
	handleMap[addr] = h
	handleLock.Unlock()

	m := MMap{}
	dh := m.header()
	dh.Data = addr
	dh.Len = length
	dh.Cap = length

	return m, nil
}