func newResizeHandler(ro resizeOpts) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
log.Println("Starting resizeHandler")
imageKey := r.URL.Path[len(ro.path):]
// fetch the query param
resizeQuery := r.URL.Query().Get("resize")
key := fmt.Sprintf("%s/%s", ro.prefix, imageKey)
if resizeQuery == "" {
log.Println("Completed resizeHandler: Redirected, no resize parameter")
urlStr := fmt.Sprintf("https://s3-%s.amazonaws.com/%s/%s", ro.region, ro.bucket, key)
http.Redirect(w, r, urlStr, http.StatusTemporaryRedirect)
return
}
resizeX, resizeY, err := waltz.ParseResize(resizeQuery)
if err != nil {
log.Println("Completed resizeHandler: ERROR: Resize parameters invalid:", err.Error())
http.Error(w, "", http.StatusBadRequest)
return
}
params := &s3.GetObjectInput{
Bucket: aws.String(ro.bucket),
Key: aws.String(key),
}
log.Println("Getting", *params.Key, "from bucket", *params.Bucket)
ifNoneMatch := r.Header.Get("If-None-Match")
if ifNoneMatch != "" {
params.IfNoneMatch = aws.String(ifNoneMatch)
}
resp, err := ro.client.GetObject(params)
if err != nil {
if awsErr, ok := err.(awserr.Error); ok {
if reqErr, ok := err.(awserr.RequestFailure); ok {
// if this is a not modified error, then cut quick
if reqErr.StatusCode() == http.StatusNotModified {
log.Println("Completed resizeHandler: Object not modified")
w.WriteHeader(http.StatusNotModified)
return
}
if reqErr.StatusCode() == http.StatusNotFound {
log.Println("Completed resizeHandler: Key not found")
w.WriteHeader(http.StatusNotFound)
return
}
// A service error occurred
log.Println("Completed resizeHandler: ERROR: AWS Service error:", reqErr.Code(), reqErr.Message(), reqErr.StatusCode(), reqErr.RequestID())
http.Error(w, "", http.StatusInternalServerError)
return
}
// Generic AWS error with Code, Message, and original error (if any)
log.Println("Completed resizeHandler: ERROR: Generic AWS error:", awsErr.Code(), awsErr.Message(), awsErr.OrigErr())
http.Error(w, "", http.StatusInternalServerError)
return
}
// This case should never be hit, the SDK should always return an
// error which satisfies the awserr.Error interface.
log.Println("Completed resizeHandler: ERROR: Impossible error:", err.Error())
http.Error(w, "", http.StatusInternalServerError)
return
}
// write out the content type
w.Header().Set("Cache-control", fmt.Sprintf("public, max-age=%d", int64(imageExpiry.Seconds())))
w.Header().Set("Content-Type", *resp.ContentType)
w.Header().Set("Etag", *resp.ETag)
if err := waltz.Do(resp.Body, w, nil, resizeX, resizeY); err != nil {
log.Println("Completed resizeHandler: ERROR: Resize Error:", err.Error())
http.Error(w, "", http.StatusInternalServerError)
return
}
}
}
func main() {
// use all CPU cores for maximum performance
runtime.GOMAXPROCS(runtime.NumCPU())
// crop points
var cropTLX, cropTLY, cropBRX, cropBRY int
// resize points
var resizeX, resizeY int
// string components
var crop, resize string
flag.StringVar(&crop, "crop", "", "crop dimensions as 0x0,32x32 to indicate bounds")
flag.StringVar(&resize, "resize", "", "resize dimensions after the crop as 16x16")
flag.Parse()
var (
cropRectangle *image.Rectangle
err error
)
if crop != "" {
crop1 := strings.Split(crop, ",")
if len(crop1) != 2 {
log.Fatalf("crop invalid, should be in the form of 0x0,32x32")
}
crop2TL := strings.Split(crop1[0], "x")
if len(crop2TL) != 2 {
log.Fatalf("crop invalid, should be in the form of 0x0,32x32")
}
crop2BR := strings.Split(crop1[1], "x")
if len(crop2BR) != 2 {
log.Fatalf("crop invalid, should be in the form of 0x0,32x32")
}
if cropTLX, err = strconv.Atoi(crop2TL[0]); err != nil {
log.Fatalln("crop invalid, should be in the form of 0x0,32x32")
}
if cropTLY, err = strconv.Atoi(crop2TL[1]); err != nil {
log.Fatalln("crop invalid, should be in the form of 0x0,32x32")
}
if cropBRX, err = strconv.Atoi(crop2BR[0]); err != nil {
log.Fatalln("crop invalid, should be in the form of 0x0,32x32")
}
if cropBRY, err = strconv.Atoi(crop2BR[1]); err != nil {
log.Fatalln("crop invalid, should be in the form of 0x0,32x32")
}
cr := image.Rect(cropTLX, cropTLY, cropBRX, cropBRY)
cropRectangle = &cr
}
resize1 := strings.Split(resize, "x")
if len(resize1) < 1 {
log.Fatalln("resize invalid, should be in the form 16x16")
}
if resizeX, err = strconv.Atoi(resize1[0]); err != nil {
log.Fatalln("resize invalid, should be in the form 16x16")
}
if len(resize1) == 2 {
if resizeY, err = strconv.Atoi(resize1[1]); err != nil {
log.Fatalln("resize invalid, should be in the form 16x16")
}
}
if err := waltz.Do(os.Stdin, os.Stdout, cropRectangle, resizeX, resizeY); err != nil {
log.Fatalf("An error occured performing the resize: %s\n", err.Error())
}
}