optimize Gollum::Wiki#tree_list

lib/gollum/file.rb

@@ -56,7 +56,7 @@ module Gollum
       if entry = map.detect { |entry| entry.path.downcase == checked }
         @path    = name
         @blob    = entry.blob(@wiki.repo)
-        @version = @wiki.commit_for(version)
+        @version = version.is_a?(Grit::Commit) ? version : @wiki.commit_for(version)
         self
       end
     end

lib/gollum/git_access.rb

@@ -56,13 +56,16 @@ module Gollum
     end
 
     def commit(ref)
-      ref_is_sha = sha?(ref)
-      if sha = (!ref_is_sha && @ref_map[ref])
-        @commit_map[sha] ||= commit!(sha)
+      if sha?(ref)
+        @commit_map[ref] ||= commit!(ref)
       else
-        cm = commit!(ref)
-        @ref_map[ref]      = cm.id if !ref_is_sha
-        @commit_map[cm.id] = cm
+        if sha = @ref_map[ref]
+          commit(sha)
+        else
+          cm = commit!(ref)
+          @ref_map[ref]      = cm.id
+          @commit_map[cm.id] = cm
+        end
       end
     end
 

lib/gollum/page.rb

@@ -270,10 +270,11 @@ module Gollum
     #
     # Returns a Gollum::Page or nil if the page could not be found.
     def find(name, version)
-      map = @wiki.tree_map_for(version)
+      map = @wiki.tree_map_for(version.to_s)
       if page = find_page_in_tree(map, name)
-        page.version    = @wiki.commit_for(version)
-        page.historical = page.version.id == version
+        page.version    = version.is_a?(Grit::Commit) ? 
+          version : @wiki.commit_for(version)
+        page.historical = page.version.to_s == version.to_s
         page
       end
     rescue Grit::GitRuby::Repository::NoSuchShaFound

lib/gollum/wiki.rb

@@ -350,9 +350,11 @@ module Gollum
     #
     # Returns a flat Array of Gollum::Page instances.
     def tree_list(ref)
-      tree_map_for(ref).inject([]) do |list, entry|
+      sha    = @access.ref_to_sha(ref)
+      commit = @access.commit(sha)
+      tree_map_for(sha).inject([]) do |list, entry|
         next list unless @page_class.valid_page_name?(entry.name)
-        list << entry.page(self, @access.commit(ref))
+        list << entry.page(self, commit)
       end
     end