func putContentsClose(wc *storage.Writer, contents []byte) error {
size := len(contents)
var nn int
var err error
for nn < size {
n, err := wc.Write(contents[nn:size])
nn += n
if err != nil {
break
}
}
if err != nil {
wc.CloseWithError(err)
return err
}
return wc.Close()
}
func storeImage(rw http.ResponseWriter, req *http.Request) {
// Appengine
var c appengine.Context
// Google Cloud Storage authentication
var cc gcscontext.Context
// Google Cloud Storage bucket name
var bucketName string = ""
// Google Cloud Storage client
var client *storage.Client
// Google Cloud Storage bucket
var bucketHandle *storage.BucketHandle
// User uploaded image file name
var fileName string = uuid.New()
// Transform user uploaded image to a thumbnail file name
var fileNameThumbnail string = uuid.New()
// User uploaded image file type
var contentType string = ""
// User uploaded image file raw data
var b []byte
// Google Cloud Storage file writer
var wc *storage.Writer = nil
// Error
var err error = nil
// Result, 0: success, 1: failed
var r int = http.StatusCreated
// Set response in the end
defer func() {
// Return status. WriteHeader() must be called before call to Write
if r == http.StatusCreated {
// Changing the header after a call to WriteHeader (or Write) has no effect.
// rw.Header().Set("Location", req.URL.String()+"/"+cKey.Encode())
rw.Header().Set("Location", "http://"+bucketName+".storage.googleapis.com/"+fileName)
rw.Header().Set("X-Thumbnail", "http://"+bucketName+".storage.googleapis.com/"+fileNameThumbnail)
rw.WriteHeader(r)
} else {
http.Error(rw, http.StatusText(r), r)
}
}()
// To log information in Google APP Engine console
c = appengine.NewContext(req)
// Get data from body
b, err = ioutil.ReadAll(req.Body)
if err != nil {
c.Errorf("%s in reading body", err)
r = http.StatusInternalServerError
return
}
c.Infof("Body length %d bytes, read %d bytes", req.ContentLength, len(b))
// Determine filename extension from content type
contentType = req.Header["Content-Type"][0]
switch contentType {
case "image/jpeg":
fileName += ".jpg"
fileNameThumbnail += ".jpg"
default:
c.Errorf("Unknown or unsupported content type '%s'. Valid: image/jpeg", contentType)
r = http.StatusBadRequest
return
}
c.Infof("Content type %s is received, %s is detected.", contentType, http.DetectContentType(b))
// Prepare Google Cloud Storage authentication
cc = gcsappengine.NewContext(req)
if client, err = storage.NewClient(cc); err != nil {
c.Errorf("%s in initializing a GCS client", err)
r = http.StatusInternalServerError
return
}
defer client.Close()
// Get default bucket
if bucketName, err = gcsfile.DefaultBucketName(cc); err != nil {
c.Errorf("%s in getting default GCS bucket name", err)
r = http.StatusInternalServerError
return
}
bucketHandle = client.Bucket(bucketName)
c.Infof("APP Engine Version: %s", gcsappengine.VersionID(cc))
c.Infof("Using bucket name: %s", bucketName)
// Change default object ACLs
if err = bucketHandle.DefaultObjectACL().Set(cc, storage.AllUsers, storage.RoleReader); err != nil {
c.Errorf("%v in saving default object ACL rule for bucket %q", err, bucketName)
r = http.StatusInternalServerError
return
}
// Store rotated image in Google Cloud Storage
var in *bytes.Reader = bytes.NewReader(b)
var x *exif.Exif = nil
var orientation *tiff.Tag = nil
var beforeImage image.Image
var afterImage *image.NRGBA = nil
// Read EXIF
if _, err = in.Seek(0, 0); err != nil {
c.Errorf("%s in moving the reader offset to the beginning in order to read EXIF", err)
return
}
if x, err = exif.Decode(in); err != nil {
c.Errorf("%s in decoding JPEG image", err)
return
}
// Get Orientation
if orientation, err = x.Get(exif.Orientation); err != nil {
c.Warningf("%s in getting orientation from EXIF", err)
return
}
c.Debugf("Orientation %s", orientation.String())
// Open image
if _, err = in.Seek(0, 0); err != nil {
c.Errorf("%s in moving the reader offset to the beginning in order to read EXIF", err)
return
}
if beforeImage, err = imaging.Decode(in); err != nil {
c.Errorf("%s in opening image %s", err)
return
}
switch orientation.String() {
case "1":
afterImage = beforeImage.(*image.NRGBA)
case "2":
afterImage = imaging.FlipH(beforeImage)
case "3":
afterImage = imaging.Rotate180(beforeImage)
case "4":
afterImage = imaging.FlipV(beforeImage)
case "5":
afterImage = imaging.Transverse(beforeImage)
case "6":
afterImage = imaging.Rotate270(beforeImage)
case "7":
afterImage = imaging.Transpose(beforeImage)
case "8":
afterImage = imaging.Rotate90(beforeImage)
}
// Save rotated image
wc = bucketHandle.Object(fileName).NewWriter(cc)
wc.ContentType = contentType
if err = imaging.Encode(wc, afterImage, imaging.JPEG); err != nil {
c.Errorf("%s in saving rotated image", err)
return
}
if err = wc.Close(); err != nil {
c.Errorf("CreateFile: unable to close bucket %q, file %q: %v", bucketName, fileName, err)
r = 1
return
}
wc = nil
// Make thumbnail
if afterImage.Rect.Dx() > afterImage.Rect.Dy() {
afterImage = imaging.Resize(afterImage, 1920, 0, imaging.Lanczos)
} else {
afterImage = imaging.Resize(afterImage, 0, 1920, imaging.Lanczos)
}
// Save thumbnail
wc = bucketHandle.Object(fileNameThumbnail).NewWriter(cc)
wc.ContentType = contentType
if imaging.Encode(wc, afterImage, imaging.JPEG); err != nil {
c.Errorf("%s in saving image thumbnail", err)
return
}
if err = wc.Close(); err != nil {
c.Errorf("CreateFileThumbnail: unable to close bucket %q, file %q: %v", bucketName, fileNameThumbnail, err)
r = 1
return
}
c.Infof("/%v/%v, /%v/%v created", bucketName, fileName, bucketName, fileNameThumbnail)
}