Sort cache entries only when choosing eviction order

CHANGELOG.md

@@ -1,5 +1,7 @@
 **Master**
 
+- Sort cache entries only when choosing eviction order. [Oskar Eichler](https://github.com/OskarEichler)
+
 Get upgrade notes from Sprockets 3.x to 4.x at https://github.com/rails/sprockets/blob/master/UPGRADING.md
 
 # 4.4.1

README.md

@@ -42,6 +42,8 @@ If you want to work on Sprockets or better understand how it works read [How Spr
 
 ## Behavior Overview
 
+Initial file cache size calculation does not sort entries; eviction still sorts by modification time before choosing files to remove.
+
 You can interact with Sprockets primarily through directives and file extensions. This section covers how to use each of these things, and the defaults that ship with Sprockets.
 
 Since you are likely using Sprockets through another framework (such as the [Rails asset pipeline](http://guides.rubyonrails.org/asset_pipeline.html)), there will be configuration options you can toggle that will change behavior such as what directories or files get compiled. For that documentation you should see your framework's documentation.

lib/sprockets/cache/file_store.rb

@@ -149,16 +149,15 @@ def clear(options=nil)
       private
         # Internal: Get all cache files along with stats.
         #
-        # Returns an Array of [String filename, File::Stat] pairs sorted by
-        # mtime.
+        # Returns an Array of [String filename, File::Stat] pairs.
         def find_caches
           Dir.glob(File.join(@root, '**/*.cache')).reduce([]) { |stats, filename|
             stat = safe_stat(filename)
             # stat maybe nil if file was removed between the time we called
             # dir.glob and the next stat
             stats << [filename, stat] if stat
             stats
-          }.sort_by { |_, stat| stat.mtime.to_i }
+          }
         end
 
         def size
@@ -185,7 +184,7 @@ def safe_open(path, &block)
         def gc!
           start_time = Time.now
 
-          caches = find_caches
+          caches = find_caches.sort_by { |_, stat| stat.mtime.to_i }
           size = compute_size(caches)
 
           delete_caches, keep_caches = caches.partition { |filename, stat|