added full pending post unit test

app/logical/download.rb

@@ -0,0 +1,87 @@
+class Download
+  class Error < Exception ; end
+  
+  attr_accessor :source, :content_type
+  
+  def initialize(source, file_path)
+    @source = source
+    @file_path = file_path
+  end
+
+  # Downloads to @file_path
+  def download!
+    http_get_streaming(@source) do |response|
+      self.content_type = response["Content-Type"]
+      File.open(@file_path, "wb") do |out|
+        response.read_body(out)
+      end
+    end
+    @source = fix_image_board_sources(@source)
+  end
+
+# private
+  def handle_pixiv(source, headers)
+    if source =~ /pixiv\.net/
+      headers["Referer"] = "http://www.pixiv.net"
+
+      # Don't download the small version
+      if source =~ %r!(/img/.+?/.+?)_m.+$!
+        match = $1
+        source.sub!(match + "_m", match)
+      end
+    end
+  
+    source
+  end
+
+  def http_get_streaming(source, options = {})
+    max_size = options[:max_size] || Danbooru.config.max_file_size
+    max_size = nil if max_size == 0 # unlimited
+    limit = 4
+
+    while true
+      url = URI.parse(source)
+
+      unless url.is_a?(URI::HTTP)
+        raise Error.new("URL must be HTTP")
+      end
+
+      Net::HTTP.start(url.host, url.port) do |http|
+        http.read_timeout = 10
+        headers = {
+          "User-Agent" => "#{Danbooru.config.safe_app_name}/#{Danbooru.config.version}"
+        }
+        source = handle_pixiv(source, headers)
+        http.request_get(url.request_uri, headers) do |res|
+          case res
+          when Net::HTTPSuccess then
+            if max_size
+              len = res["Content-Length"]
+              raise Error.new("File is too large (#{len} bytes)") if len && len.to_i > max_size
+            end
+            yield(res)
+            return
+
+          when Net::HTTPRedirection then
+            if limit == 0 then
+              raise Error.new("Too many redirects")
+            end
+            source = res["location"]
+            limit -= 1
+
+          else
+            raise Error.new("HTTP error code: #{res.code} #{res.message}")
+          end
+        end # http.request_get
+      end # http.start
+    end # while
+  end # def
+
+  def fix_image_board_sources(source)
+    if source =~ /\/src\/\d{12,}|urnc\.yi\.org|yui\.cynthia\.bne\.jp/
+      "Image board"
+    else
+      source
+    end
+  end
+end