image proxy: replace HTTParty with Danbooru::Http.

app/controllers/uploads_controller.rb

@@ -21,7 +21,7 @@ class UploadsController < ApplicationController
   def image_proxy
     authorize Upload
     resp = ImageProxy.get_image(params[:url])
-    send_data resp.body, :type => resp.content_type, :disposition => "inline"
+    send_data resp.body, type: resp.mime_type, disposition: "inline"
   end
 
   def index

app/logical/image_proxy.rb

@@ -1,4 +1,6 @@
 class ImageProxy
+  class Error < StandardError; end
+
   def self.needs_proxy?(url)
     fake_referer_for(url).present?
   end
@@ -8,16 +10,13 @@ class ImageProxy
   end
 
   def self.get_image(url)
-    if url.blank?
-      raise "Must specify url"
-    end
+    raise Error, "URL not present" unless url.present?
+    raise Error, "Proxy not allowed for this url (url=#{url})" unless needs_proxy?(url)
 
-    if !needs_proxy?(url)
-      raise "Proxy not allowed for this site"
-    end
+    referer = fake_referer_for(url)
+    response = Danbooru::Http.headers(Referer: referer).get(url)
+    raise Error, "Couldn't proxy image (code=#{response.status}, url=#{url})" unless response.status.success?
 
-    response = HTTParty.get(url, Danbooru.config.httparty_options.deep_merge(headers: {"Referer" => fake_referer_for(url)}))
-    raise "HTTP error code: #{response.code} #{response.message}" unless response.success?
     response
   end
 end