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imgproxy/process.go
2018-10-01 21:00:33 +06:00

533 lines
10 KiB
Go

package main
/*
#cgo pkg-config: vips
#cgo LDFLAGS: -s -w
#include "vips.h"
*/
import "C"
import (
"errors"
"log"
"math"
"os"
"runtime"
"unsafe"
)
type imageType int
const (
UNKNOWN = C.UNKNOWN
JPEG = C.JPEG
PNG = C.PNG
WEBP = C.WEBP
GIF = C.GIF
)
var imageTypes = map[string]imageType{
"jpeg": JPEG,
"jpg": JPEG,
"png": PNG,
"webp": WEBP,
"gif": GIF,
}
type gravityType int
const (
CENTER gravityType = iota
NORTH
EAST
SOUTH
WEST
SMART
)
var gravityTypes = map[string]gravityType{
"ce": CENTER,
"no": NORTH,
"ea": EAST,
"so": SOUTH,
"we": WEST,
"sm": SMART,
}
type resizeType int
const (
FIT resizeType = iota
FILL
CROP
)
var resizeTypes = map[string]resizeType{
"fit": FIT,
"fill": FILL,
"crop": CROP,
}
type processingOptions struct {
Resize resizeType
Width int
Height int
Gravity gravityType
Enlarge bool
Format imageType
}
var vipsSupportSmartcrop bool
var vipsTypeSupportLoad = make(map[imageType]bool)
var vipsTypeSupportSave = make(map[imageType]bool)
type cConfig struct {
Quality C.int
JpegProgressive C.int
PngInterlaced C.int
}
var cConf cConfig
func initVips() {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if err := C.vips_initialize(); err != 0 {
C.vips_shutdown()
log.Fatalln("unable to start vips!")
}
// Disable libvips cache. Since processing pipeline is fine tuned, we won't get much profit from it.
// Enabled cache can cause SIGSEGV on Musl-based systems like Alpine.
C.vips_cache_set_max_mem(0)
C.vips_cache_set_max(0)
if len(os.Getenv("IMGPROXY_VIPS_LEAK_CHECK")) > 0 {
C.vips_leak_set(C.gboolean(1))
}
if len(os.Getenv("IMGPROXY_VIPS_CACHE_TRACE")) > 0 {
C.vips_cache_set_trace(C.gboolean(1))
}
vipsSupportSmartcrop = C.vips_support_smartcrop() == 1
if int(C.vips_type_find_load_go(C.JPEG)) != 0 {
vipsTypeSupportLoad[JPEG] = true
}
if int(C.vips_type_find_load_go(C.PNG)) != 0 {
vipsTypeSupportLoad[PNG] = true
}
if int(C.vips_type_find_load_go(C.WEBP)) != 0 {
vipsTypeSupportLoad[WEBP] = true
}
if int(C.vips_type_find_load_go(C.GIF)) != 0 {
vipsTypeSupportLoad[GIF] = true
}
if int(C.vips_type_find_save_go(C.JPEG)) != 0 {
vipsTypeSupportSave[JPEG] = true
}
if int(C.vips_type_find_save_go(C.PNG)) != 0 {
vipsTypeSupportSave[PNG] = true
}
if int(C.vips_type_find_save_go(C.WEBP)) != 0 {
vipsTypeSupportSave[WEBP] = true
}
cConf.Quality = C.int(conf.Quality)
if conf.JpegProgressive {
cConf.JpegProgressive = C.int(1)
}
if conf.PngInterlaced {
cConf.PngInterlaced = C.int(1)
}
}
func shutdownVips() {
C.vips_shutdown()
}
func randomAccessRequired(po processingOptions) int {
if po.Gravity == SMART {
return 1
}
return 0
}
func round(f float64) int {
return int(f + .5)
}
func extractMeta(img *C.VipsImage) (int, int, int, bool) {
width := int(img.Xsize)
height := int(img.Ysize)
angle := C.VIPS_ANGLE_D0
flip := false
orientation := C.vips_get_exif_orientation(img)
if orientation >= 5 && orientation <= 8 {
width, height = height, width
}
if orientation == 3 || orientation == 4 {
angle = C.VIPS_ANGLE_D180
}
if orientation == 5 || orientation == 6 {
angle = C.VIPS_ANGLE_D90
}
if orientation == 7 || orientation == 8 {
angle = C.VIPS_ANGLE_D270
}
if orientation == 2 || orientation == 4 || orientation == 5 || orientation == 7 {
flip = true
}
return width, height, angle, flip
}
func calcScale(width, height int, po processingOptions) float64 {
if (po.Width == width && po.Height == height) || (po.Resize != FILL && po.Resize != FIT) {
return 1
}
fsw, fsh, fow, foh := float64(width), float64(height), float64(po.Width), float64(po.Height)
wr := fow / fsw
hr := foh / fsh
if po.Resize == FIT {
return math.Min(wr, hr)
}
return math.Max(wr, hr)
}
func calcShink(scale float64, imgtype imageType) int {
shrink := int(1.0 / scale)
if imgtype != JPEG {
return shrink
}
switch {
case shrink >= 16:
return 8
case shrink >= 8:
return 4
case shrink >= 4:
return 2
}
return 1
}
func calcCrop(width, height int, po processingOptions) (left, top int) {
left = (width - po.Width + 1) / 2
top = (height - po.Height + 1) / 2
if po.Gravity == NORTH {
top = 0
}
if po.Gravity == EAST {
left = width - po.Width
}
if po.Gravity == SOUTH {
top = height - po.Height
}
if po.Gravity == WEST {
left = 0
}
return
}
func processImage(data []byte, imgtype imageType, po processingOptions, t *timer) ([]byte, error) {
defer C.vips_cleanup()
defer runtime.KeepAlive(data)
if po.Gravity == SMART && !vipsSupportSmartcrop {
return nil, errors.New("Smart crop is not supported by used version of libvips")
}
img, err := vipsLoadImage(data, imgtype, 1)
if err != nil {
return nil, err
}
defer C.clear_image(&img)
t.Check()
imgWidth, imgHeight, angle, flip := extractMeta(img)
// Ensure we won't crop out of bounds
if !po.Enlarge || po.Resize == CROP {
if imgWidth < po.Width {
po.Width = imgWidth
}
if imgHeight < po.Height {
po.Height = imgHeight
}
}
if po.Width != imgWidth || po.Height != imgHeight {
if po.Resize == FILL || po.Resize == FIT {
scale := calcScale(imgWidth, imgHeight, po)
// Do some shrink-on-load
if scale < 1.0 {
if imgtype == JPEG || imgtype == WEBP {
shrink := calcShink(scale, imgtype)
scale = scale * float64(shrink)
if tmp, e := vipsLoadImage(data, imgtype, shrink); e == nil {
C.swap_and_clear(&img, tmp)
} else {
return nil, e
}
}
}
premultiplied := false
var bandFormat C.VipsBandFormat
if vipsImageHasAlpha(img) {
if bandFormat, err = vipsPremultiply(&img); err != nil {
return nil, err
}
premultiplied = true
}
if err = vipsResize(&img, scale); err != nil {
return nil, err
}
if premultiplied {
if err = vipsUnpremultiply(&img, bandFormat); err != nil {
return nil, err
}
}
}
}
if err = vipsImportColourProfile(&img); err != nil {
return nil, err
}
if err = vipsFixColourspace(&img); err != nil {
return nil, err
}
t.Check()
if angle != C.VIPS_ANGLE_D0 || flip {
if err = vipsImageCopyMemory(&img); err != nil {
return nil, err
}
if angle != C.VIPS_ANGLE_D0 {
if err = vipsRotate(&img, angle); err != nil {
return nil, err
}
}
if flip {
if err = vipsFlip(&img); err != nil {
return nil, err
}
}
}
t.Check()
if (po.Width != imgWidth || po.Height != imgHeight) && (po.Resize == FILL || po.Resize == CROP) {
if po.Gravity == SMART {
if err = vipsImageCopyMemory(&img); err != nil {
return nil, err
}
if err = vipsSmartCrop(&img, po.Width, po.Height); err != nil {
return nil, err
}
} else {
left, top := calcCrop(int(img.Xsize), int(img.Ysize), po)
if err = vipsCrop(&img, left, top, po.Width, po.Height); err != nil {
return nil, err
}
}
t.Check()
}
return vipsSaveImage(img, po.Format)
}
func vipsLoadImage(data []byte, imgtype imageType, shrink int) (*C.struct__VipsImage, error) {
var img *C.struct__VipsImage
if C.vips_load_buffer(unsafe.Pointer(&data[0]), C.size_t(len(data)), C.int(imgtype), C.int(shrink), &img) != 0 {
return nil, vipsError()
}
return img, nil
}
func vipsSaveImage(img *C.struct__VipsImage, imgtype imageType) ([]byte, error) {
var ptr unsafe.Pointer
defer C.g_free_go(&ptr)
err := C.int(0)
imgsize := C.size_t(0)
switch imgtype {
case JPEG:
err = C.vips_jpegsave_go(img, &ptr, &imgsize, 1, cConf.Quality, cConf.JpegProgressive)
case PNG:
err = C.vips_pngsave_go(img, &ptr, &imgsize, cConf.PngInterlaced)
case WEBP:
err = C.vips_webpsave_go(img, &ptr, &imgsize, 1, cConf.Quality)
}
if err != 0 {
return nil, vipsError()
}
return C.GoBytes(ptr, C.int(imgsize)), nil
}
func vipsImageHasAlpha(img *C.struct__VipsImage) bool {
return C.vips_image_hasalpha_go(img) > 0
}
func vipsPremultiply(img **C.struct__VipsImage) (C.VipsBandFormat, error) {
var tmp *C.struct__VipsImage
format := C.vips_band_format(*img)
if C.vips_premultiply_go(*img, &tmp) != 0 {
return 0, vipsError()
}
C.swap_and_clear(img, tmp)
return format, nil
}
func vipsUnpremultiply(img **C.struct__VipsImage, format C.VipsBandFormat) error {
var tmp *C.struct__VipsImage
if C.vips_unpremultiply_go(*img, &tmp) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
if C.vips_cast_go(*img, &tmp, format) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
return nil
}
func vipsResize(img **C.struct__VipsImage, scale float64) error {
var tmp *C.struct__VipsImage
if C.vips_resize_go(*img, &tmp, C.double(scale)) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
return nil
}
func vipsRotate(img **C.struct__VipsImage, angle int) error {
var tmp *C.struct__VipsImage
if C.vips_rot_go(*img, &tmp, C.VipsAngle(angle)) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
return nil
}
func vipsFlip(img **C.struct__VipsImage) error {
var tmp *C.struct__VipsImage
if C.vips_flip_horizontal_go(*img, &tmp) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
return nil
}
func vipsCrop(img **C.struct__VipsImage, left, top, width, height int) error {
var tmp *C.struct__VipsImage
if C.vips_extract_area_go(*img, &tmp, C.int(left), C.int(top), C.int(width), C.int(height)) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
return nil
}
func vipsSmartCrop(img **C.struct__VipsImage, width, height int) error {
var tmp *C.struct__VipsImage
if C.vips_smartcrop_go(*img, &tmp, C.int(width), C.int(height)) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
return nil
}
func vipsImportColourProfile(img **C.struct__VipsImage) error {
var tmp *C.struct__VipsImage
if C.vips_need_icc_import(*img) > 0 {
profile, err := cmykProfilePath()
if err != nil {
return err
}
if C.vips_icc_import_go(*img, &tmp, C.CString(profile)) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
}
return nil
}
func vipsFixColourspace(img **C.struct__VipsImage) error {
var tmp *C.struct__VipsImage
if C.vips_image_guess_interpretation(*img) != C.VIPS_INTERPRETATION_sRGB {
if C.vips_colourspace_go(*img, &tmp, C.VIPS_INTERPRETATION_sRGB) != 0 {
return vipsError()
}
C.swap_and_clear(img, tmp)
}
return nil
}
func vipsImageCopyMemory(img **C.struct__VipsImage) error {
var tmp *C.struct__VipsImage
if tmp = C.vips_image_copy_memory(*img); tmp == nil {
return vipsError()
}
C.swap_and_clear(img, tmp)
return nil
}
func vipsError() error {
return errors.New(C.GoString(C.vips_error_buffer()))
}