Albumに画像のダウンロード機能を移植 refs #900

3 files changed, 153 insertions, 46 deletions

diff --git a/core/plugin/openimg/model/album.rb b/core/plugin/openimg/model/album.rb
index a120ff2f..d377d044 100644
--- a/core/plugin/openimg/model/album.rb
+++ b/core/plugin/openimg/model/album.rb
@@ -4,7 +4,8 @@ module Plugin::Openimg
   class Album < Retriever::Model
     register :openimg_photo, name: Plugin[:openimg]._('画像ビューア')
 
-    field.uri :perma_link
+    field.uri    :perma_link
+    field.string :blob
 
     handle ->uri{
       uri_str = uri.to_s
@@ -13,5 +14,133 @@ module Plugin::Openimg
     } do |uri|
       new(perma_link: uri)
     end
+
+    # 画像をダウンロードする。
+    # partialを指定すると、ダウンロードの進捗があれば、前回呼び出されたときから
+    # ダウンロードできた内容を引数に呼び出される。
+    # 既にダウンロードが終わっていれば、 _blob_ の戻り値がそのまま渡される。
+    # このメソッドは、複数回呼び出されても画像のダウンロードを一度しか行わない。
+    # ==== Args
+    # [&partial_callback] 現在ダウンロードできたデータの一部(String)
+    # ==== Return
+    # [Delayer::Deferred::Deferredable] ダウンロードが完了したらselfを引数に呼び出される
+    def download(&partial_callback)      # :yield: part
+      case @state
+      when :complete
+        partial_callback.(blob) if block_given?
+        Delayer::Deferred.new.next{ self }
+      when :download
+        append_download_queue(&partial_callback)
+      else
+        download!(&partial_callback)
+      end
+    end
+
+    # 画像のダウンロードが終わっていれば真を返す。
+    # 真を返す時、 _blob_ には完全な画像の情報が存在している
+    def completed?
+      @state == :complete
+    end
+
+    # 画像をダウロード中なら真
+    def downloading?
+      @state == :download
+    end
+
+    # ダウンロードが始まっていなければ真
+    def ready?
+      !@state
+    end
+
+    private
+
+    def download!(&partial_callback)
+      atomic do
+        return download(&partial_callback) unless ready?
+        promise = initialize_download(&partial_callback)
+        Thread.new(&gen_download_routine).next{|success|
+          if success
+            finalize_download_as_success
+          else
+            Delayer::Deferred.fail false
+          end
+        }.trap{|exception|
+          finalize_download_as_fail(exception)
+        }.terminate('error')
+        promise
+      end
+    end
+
+    def append_download_queue(&partial_callback)
+      atomic do
+        return download(&partial_callback) unless downloading?
+        register_partial_callback(partial_callback)
+        register_promise
+      end
+    end
+
+    def register_promise
+      promise = Delayer::Deferred.new(true)
+      (@promises ||= Set.new) << promise
+      promise
+    end
+
+    def register_partial_callback(cb)
+      @partials ||= Set.new
+      if cb
+        @partials  << cb
+        cb.(@buffer) if !@buffer.empty?
+      end
+    end
+
+    def gen_download_routine
+      -> do
+        begin
+          _, raw = Plugin.filtering(:openimg_raw_image_from_display_url, perma_link.to_s, nil)
+          if raw
+            download_mainloop(raw)
+          else
+            raise "couldn't resolve actual image url of #{perma_link}."
+          end
+        rescue EOFError
+          true
+        ensure
+          raw.close rescue nil
+        end
+      end
+    end
+
+    def download_mainloop(raw)
+      loop do
+        Thread.pass
+        partial = raw.readpartial(1024*HYDE).freeze
+        @buffer << partial
+        atomic{ @partials.each{|c|c.(partial)} }
+      end
+    end
+
+    def initialize_download(&partial_callback)
+      @state = :download
+      @buffer = String.new
+      register_partial_callback(partial_callback)
+      register_promise
+    end
+
+    def finalize_download_as_success
+      atomic do
+        self.blob = @buffer.freeze
+        @state = :complete
+        @promises.each{|p| p.call(self) }
+        @buffer = @promises = @partials = nil
+      end
+    end
+
+    def finalize_download_as_fail(exception)
+      atomic do
+        @state = nil
+        @promises.each{|p| p.fail(exception) }
+        @buffer = @promises = @partials = nil
+      end
+    end
   end
 end
diff --git a/core/plugin/openimg/openimg.rb b/core/plugin/openimg/openimg.rb
index db0f245d..4af451a1 100644
--- a/core/plugin/openimg/openimg.rb
+++ b/core/plugin/openimg/openimg.rb
@@ -44,30 +44,10 @@ Plugin.create :openimg do
       error _
       nil end end
 
-  filter_openimg_pixbuf_from_display_url do |display_url, loader, thread|
-    raw  = Plugin.filtering(:openimg_raw_image_from_display_url, display_url, nil).last
-    if raw
-      begin
-        loader = Gdk::PixbufLoader.new
-        thread = Thread.new do
-          begin
-            loop do
-              Thread.pass
-              partial = raw.readpartial(1024*HYDE)
-              atomic{ loader.write partial }
-            end
-            nil
-          rescue EOFError
-            true
-          ensure
-            raw.close rescue nil
-            loader.close rescue nil end end
-        [display_url, loader, thread]
-      rescue => _
-        error _
-        [display_url, loader, thread] end
-    else
-      [display_url, loader, thread] end end
+  filter_openimg_pixbuf_from_display_url do |album, loader, thread|
+    loader = Gdk::PixbufLoader.new
+    [album, loader, album.download{|partial| atomic{ loader.write partial } }]
+  end
 
   filter_openimg_raw_image_from_display_url do |display_url, content|
     unless content
@@ -80,11 +60,11 @@ Plugin.create :openimg do
     [display_url, content] end
 
   on_openimg_open do |display_url|
-    Plugin::Openimg::Window.new(display_url).start_loading.show_all
+    Plugin.call(:open, display_url)
   end
 
-  intent Plugin::Openimg::Album do |intent|
-    Plugin.call(:openimg_open, intent.model.perma_link.to_s)
+  intent Plugin::Openimg::Album do |intent_token|
+    Plugin::Openimg::Window.new(intent_token.model, intent_token).start_loading.show_all
   end
 
   def addsupport(cond, element_rule = {}, &block); end
diff --git a/core/plugin/openimg/window.rb b/core/plugin/openimg/window.rb
index 1f2e4a72..f1b59838 100644
--- a/core/plugin/openimg/window.rb
+++ b/core/plugin/openimg/window.rb
@@ -2,45 +2,43 @@
 
 module Plugin::Openimg
   class Window < Gtk::Window
-    attr_reader :display_url
+    attr_reader :album
 
-    def initialize(display_url)
+    def initialize(album, next_opener)
       super()
-      @display_url = display_url
+      @album = album
       @image_surface = loading_surface
+      @next_opener = next_opener
       window_settings
       ssc(:destroy, &:destroy)
     end
 
     def start_loading
       Thread.new {
-        Plugin.filtering(:openimg_pixbuf_from_display_url, display_url, nil, nil)
-      }.next { |_, pixbufloader, thread|
+        Plugin.filtering(:openimg_pixbuf_from_display_url, album, nil, nil)
+      }.next { |_, pixbufloader, complete_promise|
         if pixbufloader.is_a? Gdk::PixbufLoader
           pixbufloader.ssc(:area_updated, window) do |_, x, y, width, height|
             Delayer.new do
-              if thread.alive?
-                progress(pixbufloader.pixbuf, x: x, y: y, width: width, height: height) end end
+              progress(pixbufloader.pixbuf, x: x, y: y, width: width, height: height) end
             true end
 
           pixbufloader.ssc(:closed, window) do
             progress(pixbufloader.pixbuf, paint: true)
             true end
 
-          thread.next { |flag|
-            Deferred.fail flag unless flag
-          }.trap { |exception|
-            error exception
+          complete_promise.trap { |exception|
             @image_surface = error_surface
+            redraw(repaint: true)
           }
         else
-          warn "cant open: #{display_url}"
+          warn "cant open: #{album}"
           @image_surface = error_surface
-          redraw(repaint: false) end
+          redraw(repaint: true) end
       }.trap{ |exception|
         error exception
         @image_surface = error_surface
-        redraw(repaint: false)
+        redraw(repaint: true)
       }
       self
     end
@@ -48,7 +46,7 @@ module Plugin::Openimg
     private
 
     def window_settings
-      set_title(display_url)
+      set_title(album.perma_link.to_s)
       set_role('mikutter_image_preview'.freeze)
       set_type_hint(Gdk::Window::TYPE_HINT_DIALOG)
       set_default_size(*default_size)
@@ -128,14 +126,14 @@ module Plugin::Openimg
 
     def gen_browser_clicked
       proc do
-        Plugin.call(:open, @display_url)
+        Plugin.call(:open, @next_opener)
         false
       end
     end
 
     def gen_wrap_expose_event
       proc do |widget|
-        redraw(repaint: false)
+        redraw(repaint: true)
         true
       end
     end
@@ -145,7 +143,7 @@ module Plugin::Openimg
       proc do |widget|
         if widget.window && last_size != widget.window.geometry[2,2]
           last_size = widget.window.geometry[2,2]
-          redraw(repaint: false)
+          redraw(repaint: true)
         end
         false
       end