uploads: use storage manager to distribute files.

Refactors the upload process to pass around temp files, rather than
passing around file paths and directly writing output to the local
filesystem. This way we can pass the storage manager the preview /
sample / original temp files, so it can deal with storage itself.

* Change Download::File#download! to return a temp file.

* Change DanbooruImageResizer and PixivUgoiraConverter to accept/return
  temp files instead of file paths.

* Change Upload#generate_resizes to return temp files for previews and samples.

* Change Upload#generate_resizes to generate ugoira .webm samples
  synchronously instead of asynchronously.

app/logical/danbooru_image_resizer.rb

@@ -1,6 +1,6 @@
 module DanbooruImageResizer
-  def resize(read_path, write_path, width, height, resize_quality = 90)
-    image = Magick::Image.read(read_path).first
+  def resize(file, width, height, resize_quality = 90)
+    image = Magick::Image.read(file.path).first
     geometry = "#{width}x>"
 
     if width == Danbooru.config.small_image_width
@@ -17,14 +17,15 @@ module DanbooruImageResizer
     image = flatten(image, width, height)
     image.strip!
 
-    image.write(write_path) do
+    output_file = Tempfile.new(binmode: true)
+    image.write("jpeg:" + output_file.path) do
       self.quality = resize_quality
       # setting PlaneInterlace enables progressive encoding for JPEGs
       self.interlace = Magick::PlaneInterlace
     end
 
     image.destroy!
-    FileUtils.chmod(0664, write_path)
+    output_file
   end
 
   def flatten(image, width, height)

app/logical/downloads/file.rb

@@ -3,9 +3,9 @@ module Downloads
     class Error < Exception ; end
 
     attr_reader :data, :options
-    attr_accessor :source, :original_source, :downloaded_source, :file_path
+    attr_accessor :source, :original_source, :downloaded_source
 
-    def initialize(source, file_path, options = {})
+    def initialize(source, options = {})
       # source can potentially get rewritten in the course
       # of downloading a file, so check it again
       @source = source
@@ -14,9 +14,6 @@ module Downloads
       # the URL actually downloaded after rewriting the original source.
       @downloaded_source = nil
 
-      # where to save the download
-      @file_path = file_path
-
       # we sometimes need to capture data from the source page
       @data = {}
 
@@ -35,12 +32,13 @@ module Downloads
     def download!
       url, headers, @data = before_download(@source, @data)
 
-      ::File.open(@file_path, "wb") do |out|
-        http_get_streaming(uncached_url(url, headers), out, headers)
-      end
+      output_file = Tempfile.new(binmode: true)
+      http_get_streaming(uncached_url(url, headers), output_file, headers)
 
       @downloaded_source = url
       @source = after_download(url)
+
+      output_file
     end
 
     def before_download(url, datums)
@@ -91,7 +89,8 @@ module Downloads
           end
 
           if res.success?
-            return
+            file.rewind
+            return file
           else
             raise Error.new("HTTP error code: #{res.code} #{res.message}")
           end

app/logical/pixiv_ugoira_converter.rb

@@ -1,13 +1,9 @@
 class PixivUgoiraConverter
-  def self.convert(source_path, output_path, preview_path, frame_data)
-    folder = Zip::File.new(source_path)
-    write_webm(folder, output_path, frame_data)
-    write_preview(folder, preview_path)
-    RemoteFileManager.new(output_path).distribute
-    RemoteFileManager.new(preview_path).distribute
-  end
+  def self.generate_webm(ugoira_file, frame_data)
+    folder = Zip::File.new(ugoira_file.path)
+    output_file = Tempfile.new(binmode: true)
+    write_path = output_file.path
 
-  def self.write_webm(folder, write_path, frame_data)
     Dir.mktmpdir do |tmpdir|
       FileUtils.mkdir_p("#{tmpdir}/images")
       folder.each_with_index do |file, i|
@@ -64,14 +60,17 @@ class PixivUgoiraConverter
         return
       end
     end
+
+    output_file
   end
 
-  def self.write_preview(folder, path)
-    Dir.mktmpdir do |tmpdir|
-      file = folder.first
-      temp_path = File.join(tmpdir, file.name)
-      file.extract(temp_path)
-      DanbooruImageResizer.resize(temp_path, path, Danbooru.config.small_image_width, Danbooru.config.small_image_width, 85)
-    end
+  def self.generate_preview(ugoira_file)
+    file = Tempfile.new(binmode: true)
+    zipfile = Zip::File.new(ugoira_file.path)
+    zipfile.entries.first.extract(file.path) { true } #  'true' means overwrite the existing tempfile.
+
+    DanbooruImageResizer.resize(file, Danbooru.config.small_image_width, Danbooru.config.small_image_width, 85)
+  ensure
+    file.close!
   end
 end

app/logical/pixiv_ugoira_service.rb

@@ -1,32 +1,10 @@
 class PixivUgoiraService
   attr_reader :width, :height, :frame_data, :content_type
 
-  def self.regen(post)
-    service = new()
-    service.load(
-      :is_ugoira => true,
-      :ugoira_frame_data => post.pixiv_ugoira_frame_data.data
-    )
-    service.generate_resizes(post.file_path, post.large_file_path, post.preview_file_path, false)
-  end
-
   def save_frame_data(post)
     PixivUgoiraFrameData.create(:data => @frame_data, :content_type => @content_type, :post_id => post.id)
   end
 
-  def generate_resizes(source_path, output_path, preview_path, delay = true)
-    # Run this a bit in the future to give the upload process time to move the file
-    if delay
-      PixivUgoiraConverter.delay(:queue => Socket.gethostname, :run_at => 10.seconds.from_now, :priority => -1).convert(source_path, output_path, preview_path, @frame_data)
-    else
-      PixivUgoiraConverter.convert(source_path, output_path, preview_path, @frame_data)
-    end
-
-    # since the resizes will be delayed, just touch the output file so the
-    # file distribution wont break
-    FileUtils.touch([output_path, preview_path])
-  end
-
   def calculate_dimensions(source_path)
     folder = Zip::File.new(source_path)
     tempfile = Tempfile.new("ugoira-dimensions")