use Zlib.crc2 rather that bytes.sum, as per Aaron's suggestion

That integer is rather irrelevant, the only thing that matters is that
it is consistent and with no apparent bias. Zlib.crc32 is 8-10 times
faster than bytes.sum, so use that.

2 files changed, 4 insertions, 3 deletions

diff --git a/actionpack/lib/action_view/asset_paths.rb b/actionpack/lib/action_view/asset_paths.rb
index 77a8c5322f..96d8fd0dfe 100644
--- a/actionpack/lib/action_view/asset_paths.rb
+++ b/actionpack/lib/action_view/asset_paths.rb
@@ -1,3 +1,4 @@
+require 'zlib'
 require 'active_support/core_ext/file'
 
 module ActionView
@@ -111,8 +112,7 @@ module ActionView
           args << current_request if (arity > 1 || arity < 0) && has_request?
           host.call(*args)
         else
-          source_num = source.bytes.sum
-          (host =~ /%d/) ? host % (source_num % 4) : host
+          (host =~ /%d/) ? host % (Zlib.crc32(source) % 4) : host
         end
       end
     end
diff --git a/actionpack/test/template/asset_tag_helper_test.rb b/actionpack/test/template/asset_tag_helper_test.rb
index 717e0e9065..d5bd7256f7 100644
--- a/actionpack/test/template/asset_tag_helper_test.rb
+++ b/actionpack/test/template/asset_tag_helper_test.rb
@@ -1,3 +1,4 @@
+require 'zlib'
 require 'abstract_unit'
 require 'active_support/ordered_options'
 
@@ -689,7 +690,7 @@ class AssetTagHelperTest < ActionView::TestCase
     @controller.config.asset_host = 'http://a%d.example.com'
     config.perform_caching = true
 
-    number = '/javascripts/cache/money.js'.bytes.sum % 4
+    number = Zlib.crc32('/javascripts/cache/money.js') % 4
     assert_dom_equal(
       %(<script src="http://a#{number}.example.com/javascripts/cache/money.js" type="text/javascript"></script>),
       javascript_include_tag(:all, :cache => "cache/money")