Merge pull request #75 from jschwindt/master

Data URIs scheme handling

README.textile

@@ -37,6 +37,8 @@ FastImage accepts additional HTTP headers. This can be used to set a user agent
 
 FastImage can give you information about the parsed display orientation of an image with Exif data (jpeg or tiff).
 
+FastImage also handles "Data URIs":https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs correctly.
+
 h2. Security
 
 As of v1.6.7 FastImage no longer uses @openuri@ to open files, but directly calls @File.open@. Take care to sanitise the strings passed to FastImage; it will try to read from whatever is passed.
@@ -62,6 +64,8 @@ FastImage.size("http://stephensykes.com/images/ss.com_x.gif", :http_header => {'
 => [266, 56]
 FastImage.new("http://stephensykes.com/images/ExifOrientation3.jpg").orientation
 => 3
+FastImage.size("data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==")
+=> [1, 1]
 </code></pre>
 
 h2. Installation
@@ -97,7 +101,7 @@ irb> uri = "http://upload.wikimedia.org/wikipedia/commons/b/b4/Mardin_1350660_13
 irb> puts Benchmark.measure {open(uri, 'rb') {|fh| p ImageSize.new(fh).size}}
 [9545, 6623]
   0.680000   0.250000   0.930000 (  7.571887)
-  
+
 irb> puts Benchmark.measure {p FastImage.size(uri)}
 [9545, 6623]
   0.010000   0.000000   0.010000 (  0.090640)
@@ -114,7 +118,7 @@ irb> uri = "http://upload.wikimedia.org/wikipedia/commons/1/11/Shinbutsureijoush
 irb> puts Benchmark.measure {open(uri, 'rb') {|fh| p ImageSize.new(fh).size}}
 [1120, 1559]
   1.080000   0.370000   1.450000 ( 13.766962)
-  
+
 irb> puts Benchmark.measure {p FastImage.size(uri)}
 [1120, 1559]
   3.490000   3.810000   7.300000 ( 11.754315)
@@ -124,8 +128,8 @@ h2. Tests
 
 You'll need to @gem install fakeweb@ and possibly also  @gem install test-unit@ to be able to run the tests.
 
-bc.. $ ruby test.rb 
-Run options: 
+bc.. $ ruby test.rb
+Run options:
 
 # Running tests:
 

lib/fastimage.rb

@@ -28,7 +28,7 @@
 # or referrer which some servers require. Pass an :http_header argument to specify headers,
 # e.g., :http_header => {'User-Agent' => 'Fake Browser'}.
 #
-# FastImage can give you information about the parsed display orientation of an image with Exif 
+# FastImage can give you information about the parsed display orientation of an image with Exif
 # data (jpeg or tiff).
 #
 # === Examples
@@ -58,6 +58,7 @@ require 'net/https'
 require 'delegate'
 require 'pathname'
 require 'zlib'
+require 'base64'
 require 'uri'
 
 # see http://stackoverflow.com/questions/5208851/i/41048816#41048816
@@ -191,6 +192,8 @@ class FastImage
 
     if uri.respond_to?(:read)
       fetch_using_read(uri)
+    elsif uri.start_with?('data:')
+      fetch_using_base64(uri)
     else
       begin
         @parsed_uri = URI.parse(uri)
@@ -358,7 +361,7 @@ class FastImage
         else
           @orientation = 1
         end
-        
+
         instance_variable_set("@#{@property}", result)
       else
         raise CannotParseImage
@@ -373,6 +376,11 @@ class FastImage
     send("parse_size_for_#{@type}")
   end
 
+  def fetch_using_base64(uri)
+    data = uri.split(',')[1]
+    fetch_using_read StringIO.new(Base64.decode64(data))
+  end
+
   module StreamUtil # :nodoc:
     def read_byte
       read(1)[0].ord
@@ -475,7 +483,7 @@ class FastImage
     when "<?"
       :svg if @stream.peek(100).include?("<svg")
     end
-    
+
     parsed_type or raise UnknownImageType
   end
 
@@ -651,7 +659,7 @@ class FastImage
       end
 
       parse_exif_ifd
-      
+
       @orientation ||= 1
     end
 

test/test.rb

@@ -56,6 +56,9 @@ LargeImageFetchLimit = 2  # seconds
 HTTPSImage = "https://upload.wikimedia.org/wikipedia/commons/b/b4/Mardin_1350660_1350692_33_images.jpg"
 HTTPSImageInfo = [:jpeg, [9545, 6623]]
 
+DataUriImage = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAIAAAABCAYAAAD0In+KAAAAD0lEQVR42mNk+M9QzwAEAAmGAYCF+yOnAAAAAElFTkSuQmCC"
+DataUriImageInfo = [:png, [2, 1]]
+
 GoodFixtures.each do |fn, info|
   FakeWeb.register_uri(:get, "#{TestUrl}#{fn}", :body => File.join(FixturePath, fn))
 end
@@ -358,13 +361,21 @@ class FastImageTest < Test::Unit::TestCase
     url = "#{TestUrl}test.gif"
     assert_equal 1, FastImage.new(url).orientation
   end
-  
+
   def test_should_raise_when_handling_invalid_ico_files
     stringio = StringIO.new("\x00\x00003")
     assert_raises(FastImage::UnknownImageType) do
       FastImage.type(stringio, :raise_on_failure => true)
     end
   end
+
+  def test_should_support_data_uri_scheme_images
+    assert_equal DataUriImageInfo[0], FastImage.type(DataUriImage)
+    assert_equal DataUriImageInfo[1], FastImage.size(DataUriImage)
+    assert_raises(FastImage::ImageFetchFailure) do
+      FastImage.type("data:", :raise_on_failure => true)
+    end
+  end
   
   def test_should_work_with_domains_with_underscores
     assert_equal :gif, FastImage.type("http://foo_bar.inbro.net/images/p.gif")