Golang C.ssize_t类(方法)实例源码

func (img *Image) Resize(width int, height int) {
	wand := img.wand

	cur_width := float64(C.MagickGetImageWidth(wand))
	cur_height := float64(C.MagickGetImageHeight(wand))

	r_width := cur_width / float64(width)
	r_height := cur_height / float64(height)

	ratio := r_height
	if r_width < r_height {
		ratio = r_width
	}

	dest_width := cur_width / ratio
	dest_height := cur_height / ratio

	crop_x := int((dest_width - float64(width)) / 2)
	crop_y := int((dest_height - float64(height)) / 2)

	if r_width > 5 && r_height > 5 {
		C.MagickSampleImage(wand, C.size_t(dest_width*5), C.size_t(dest_height*5))
	}
	C.MagickResizeImage(wand, C.size_t(dest_width), C.size_t(dest_height), C.LanczosFilter, 1)
	C.MagickCropImage(wand, C.size_t(width), C.size_t(height), C.ssize_t(crop_x), C.ssize_t(crop_y))
}

/* Extracts a region of the image. */
func (w *MagickWand) CropImage(width, height uint, x, y int) error {
	if C.MagickCropImage(w.wand, C.size_t(width), C.size_t(height), C.ssize_t(x), C.ssize_t(y)) == C.MagickFalse {
		eStr, eCode := w.Exception()
		return fmt.Errorf("CropImage() failed : [%d] %s", eStr, eCode)
	}

	return nil
}

func (im *Image) setPixels(r *Rect, src *C.PixelPacket, ex *C.ExceptionInfo) bool {
	dst := C.GetAuthenticPixels(im.image, C.ssize_t(r.X), C.ssize_t(r.Y), C.size_t(r.Width), C.size_t(r.Height), ex)
	if dst == nil {
		return false
	}
	C.copy_pixel_packets(src, dst, C.int(r.Width*r.Height))
	if C.SyncAuthenticPixels(im.image, ex) != C.MagickTrue {
		return false
	}
	return true
}

// Private: center the current wand on top of the new wand, after that, we only
// keep the new wand.
//
// Params:
// - newWand: new wand, probably going to be result of blankWand
// - x: x position on the current wand that is the center of the new wand
// - y: y position on the current wand that is the center of the new wand
//
// Example:
//  newWand := blankWand("jpg", width, height)
//  done := m.compositeCenter(newWand, 10, 10)
//
// Return boolean result of the composition
func (m *Mage) compositeCenter(newWand *C.MagickWand, x, y int) bool {
	success := C.MagickCompositeImage(
		newWand,
		m.wand,
		C.OverCompositeOp,
		C.ssize_t(x),
		C.ssize_t(y))
	C.DestroyMagickWand(m.wand)
	m.wand = newWand
	return mBoolean(success)
}

func (br *BodyReader) Read(p []byte) (n int, err error) {
	m := len(p)
	var rlen C.ssize_t = C.ssize_t(0)
	c_body := C.uwsgi_request_body_read(br.wsgi_req, C.ssize_t(m), &rlen)
	if c_body == C.uwsgi.empty {
		err = io.EOF
		return 0, err
	} else if c_body != nil {
		C.memcpy(unsafe.Pointer(&p[0]), unsafe.Pointer(c_body), C.size_t(rlen))
		return int(rlen), err
	}
	err = io.ErrUnexpectedEOF
	rlen = 0
	return int(rlen), err
}

func (e *Enchant) Replace(word, wordNew string) {
	// does the dictionary need to be loaded here?
	cWord := C.CString(word)
	defer C.free(unsafe.Pointer(cWord))

	cWordNew := C.CString(wordNew)
	defer C.free(unsafe.Pointer(cWordNew))

	cWordLen := uintptr(len(word))
	s := C.ssize_t(cWordLen)

	cWordLenNew := uintptr(len(wordNew))
	sNew := C.ssize_t(cWordLenNew)

	C.enchant_dict_store_replacement(e.dict, cWord, s, cWordNew, sNew)
}

// Puts a canvas on top of the current one.
func (cv Canvas) AppendCanvas(source Canvas, x int, y int) bool {
	status := C.MagickCompositeImage(cv.wand, source.wand, C.OverCompositeOp, C.ssize_t(x), C.ssize_t(y))
	if status == C.MagickFalse {
		return false
	}
	return true
}

// Extracts a region from the canvas.
func (cv Canvas) Crop(x int, y int, width uint, height uint) bool {
	status := C.MagickCropImage(cv.wand, C.size_t(width), C.size_t(height), C.ssize_t(x), C.ssize_t(y))
	if status == C.MagickFalse {
		return false
	}
	return true
}

/* Composite one image onto another at the specified offset. */
func (w *MagickWand) CompositeImage(srcWand *MagickWand, compose, x, y int) error {
	if C.MagickCompositeImage(w.wand, srcWand.wand, C.CompositeOperator(compose), C.ssize_t(x), C.ssize_t(y)) == C.MagickFalse {
		eStr, eCode := w.Exception()
		return fmt.Errorf("CompositeImage() failed : [%d] %s", eStr, eCode)
	}

	return nil
}

// Extracts a region from the canvas.
func (self *Canvas) Crop(x int, y int, width uint, height uint) error {
	success := C.MagickCropImage(self.wand, C.size_t(width), C.size_t(height), C.ssize_t(x), C.ssize_t(y))

	if success == C.MagickFalse {
		return fmt.Errorf("Could not crop: %s", self.Error())
	}

	return nil
}

func (acl *ACL) CopyExt(buffer []byte) (int64, error) {
	p := unsafe.Pointer(&buffer[0])
	l := C.ssize_t(len(buffer))
	i, err := C.acl_copy_ext(p, acl.a, l)
	if i < 0 {
		return int64(i), err
	}
	return int64(i), nil
}

// Puts a canvas on top of the current one.
func (self *Canvas) AppendCanvas(source *Canvas, x int, y int) error {
	success := C.MagickCompositeImage(self.wand, source.wand, C.OverCompositeOp, C.ssize_t(x), C.ssize_t(y))

	if success == C.MagickFalse {
		return fmt.Errorf("Could not append image: %s", self.Error())
	}

	return nil
}

// Check whether a given word is in the currently loaded dictionary.
// This wraps enchant_dict_check.
// It returns a boolean value: true if the word is in the dictionary,
// false otherwise.
func (d Dict) Check(word string) bool {
	if len(word) == 0 {
		return true
	}

	cWord := (*C.char)(unsafe.Pointer((*reflect.StringHeader)(unsafe.Pointer(&word)).Data))
	size := C.ssize_t(uintptr(len(word)))

	return C.enchant_dict_check(d.dict, cWord, size) == 0
}

// Write writes len(b) bytes from b into the Fd
//
// Returns number of bytes written on success and error on failure
func (fd *Fd) Write(b []byte) (int, error) {

	n, err := C.glfs_write(fd.fd, unsafe.Pointer(&b[0]), C.size_t(len(b)), 0)
	if n == C.ssize_t(len(b)) {
		// FIXME: errno is set to EINVAL even though write is successful. This
		// is probably a bug. Remove this workaround when that gets fixed.
		err = nil
	}
	return int(n), err

}

// write to a file descriptor
func fdWrite(fd C.int, d []byte) (n int, err error) {
	buff := make([]C.uchar, len(d))
	for i, b := range d {
		buff[i] = C.uchar(b)
	}
	res := C.uchar_write(fd, &buff[0], C.size_t(len(d)))
	if res == C.ssize_t(-1) {
		err = errors.New("write returned -1")
	} else {
		n = int(res)
	}
	return
}

//export gogpgme_writefunc
func gogpgme_writefunc(handle, buffer unsafe.Pointer, size C.size_t) C.ssize_t {
	d := callbackLookup(uintptr(handle)).(*Data)
	if len(d.buf) < int(size) {
		d.buf = make([]byte, size)
	}
	C.memcpy(unsafe.Pointer(&d.buf[0]), buffer, C.size_t(size))
	n, err := d.w.Write(d.buf[:size])
	if err != nil && err != io.EOF {
		C.gpgme_err_set_errno(C.EIO)
		return -1
	}
	return C.ssize_t(n)
}

// read from a file descriptor
func fdRead(fd C.int, d []byte) (n int, err error) {
	buff := make([]C.uchar, len(d))
	res := C.uchar_read(fd, &buff[0], C.size_t(len(d)))
	if res == C.ssize_t(-1) {
		err = errors.New("read returned -1")
	} else {
		n = int(res)
		for i, b := range buff[:n] {
			d[i] = byte(b)
		}
	}
	return
}

func readdelattr(filepath string) (bool, error) {
	val := C.char(0)
	err := C.getxattr(
		C.CString(filepath),
		C.CString("novm-deleted"),
		unsafe.Pointer(&val),
		C.size_t(1))
	if err != C.ssize_t(1) {
		var stat syscall.Stat_t
		err := syscall.Stat(
			path.Join(filepath, ".deleted"),
			&stat)
		if err != nil {
			return false, err
		}
		return true, nil
	}
	return val == C.char(1), nil
}

// Takes a serialized OSC packet and deserializes it into a
// message. Parameters with an unsupported type will
// be deserialized as ErrUnknown.
func Deserialize(data []byte) (*Message, error) {
	cdata := unsafe.Pointer(&data[0])
	cdatalen := C.size_t(len(data))

	msg := C.lo_message_deserialise(cdata, cdatalen, (*C.int)(unsafe.Pointer(nil)))
	if msg == nil {
		// TODO: Obtain and parse actual error?
		return nil, errors.New("Deserialization failed")
	}

	result := &Message{
		Path:   C.GoString(C.lo_get_path(cdata, C.ssize_t(cdatalen))),
		Params: make([]interface{}, 0, 10),
	}
	argc := int(C.lo_message_get_argc(msg))
	for i := 0; i < argc; i++ {
		result.Params = append(result.Params, extractArgument(msg, i))
	}
	return result, nil
}

func (im *Image) pixels(r *Rect, ex *C.ExceptionInfo) *C.PixelPacket {
	return C.GetVirtualPixels(im.image, C.ssize_t(r.X), C.ssize_t(r.Y), C.size_t(r.Width), C.size_t(r.Height), ex)
}