Make Highlight accept language param

This replaces the repository param.
This allows more flexiblity as sometimes we have highlight content
not related to repository. Sometimes we know ahead of time the language
of the content. Lastly language determination seems better fit as a
logic in the Blob class.
`repository` param is only used to determine the language, which seems
to be the responsiblity of Blob.

4 files changed, 39 insertions, 16 deletions

diff --git a/lib/gitlab/blame.rb b/lib/gitlab/blame.rb
index 0d79594363e..f1a653a9d95 100644
--- a/lib/gitlab/blame.rb
+++ b/lib/gitlab/blame.rb
@@ -43,8 +43,7 @@ module Gitlab
 
     def highlighted_lines
       @blob.load_all_data!
-      @highlighted_lines ||=
-        Gitlab::Highlight.highlight(@blob.path, @blob.data, repository: repository).lines
+      @highlighted_lines ||= @blob.present.highlight.lines
     end
 
     def project
diff --git a/lib/gitlab/conflict/file.rb b/lib/gitlab/conflict/file.rb
index 30911b49b18..501c2111530 100644
--- a/lib/gitlab/conflict/file.rb
+++ b/lib/gitlab/conflict/file.rb
@@ -3,6 +3,7 @@ module Gitlab
     class File
       include Gitlab::Routing
       include IconsHelper
+      include Gitlab::Utils::StrongMemoize
 
       CONTEXT_LINES = 3
 
@@ -30,11 +31,8 @@ module Gitlab
       end
 
       def highlight_lines!
-        their_file = lines.reject { |line| line.type == 'new' }.map(&:text).join("\n")
-        our_file = lines.reject { |line| line.type == 'old' }.map(&:text).join("\n")
-
-        their_highlight = Gitlab::Highlight.highlight(their_path, their_file, repository: repository).lines
-        our_highlight = Gitlab::Highlight.highlight(our_path, our_file, repository: repository).lines
+        their_highlight = Gitlab::Highlight.highlight(their_path, their_lines, language: their_language).lines
+        our_highlight = Gitlab::Highlight.highlight(our_path, our_lines, language: our_language).lines
 
         lines.each do |line|
           line.rich_text =
@@ -182,6 +180,34 @@ module Gitlab
             raw_line[:line_new], parent_file: self)
         end
       end
+
+      def their_language
+        strong_memoize(:their_language) do
+          repository.gitattribute(their_path, 'gitlab-language')
+        end
+      end
+
+      def our_language
+        strong_memoize(:our_language) do
+          if our_path == their_path
+            their_language
+          else
+            repository.gitattribute(our_path, 'gitlab-language')
+          end
+        end
+      end
+
+      def their_lines
+        strong_memoize(:their_lines) do
+          lines.reject { |line| line.type == 'new' }.map(&:text).join("\n")
+        end
+      end
+
+      def our_lines
+        strong_memoize(:our_lines) do
+          lines.reject { |line| line.type == 'old' }.map(&:text).join("\n")
+        end
+      end
     end
   end
 end
diff --git a/lib/gitlab/diff/highlight.rb b/lib/gitlab/diff/highlight.rb
index a605ddb5c33..1d833183ec3 100644
--- a/lib/gitlab/diff/highlight.rb
+++ b/lib/gitlab/diff/highlight.rb
@@ -79,7 +79,7 @@ module Gitlab
         return [] unless blob
 
         blob.load_all_data!
-        Gitlab::Highlight.highlight(blob.path, blob.data, repository: repository).lines
+        blob.present.highlight.lines
       end
     end
   end
diff --git a/lib/gitlab/highlight.rb b/lib/gitlab/highlight.rb
index 83095acc528..d28223194cc 100644
--- a/lib/gitlab/highlight.rb
+++ b/lib/gitlab/highlight.rb
@@ -5,16 +5,16 @@ module Gitlab
     TIMEOUT_BACKGROUND = 30.seconds
     TIMEOUT_FOREGROUND = 3.seconds
 
-    def self.highlight(blob_name, blob_content, repository: nil, plain: false)
-      new(blob_name, blob_content, repository: repository)
+    def self.highlight(blob_name, blob_content, language: nil, plain: false)
+      new(blob_name, blob_content, language: language)
         .highlight(blob_content, continue: false, plain: plain)
     end
 
     attr_reader :blob_name
 
-    def initialize(blob_name, blob_content, repository: nil)
+    def initialize(blob_name, blob_content, language: nil)
       @formatter = Rouge::Formatters::HTMLGitlab
-      @repository = repository
+      @language = language
       @blob_name = blob_name
       @blob_content = blob_content
     end
@@ -36,11 +36,9 @@ module Gitlab
     private
 
     def custom_language
-      language_name = @repository && @repository.gitattribute(@blob_name, 'gitlab-language')
+      return nil unless @language
 
-      return nil unless language_name
-
-      Rouge::Lexer.find_fancy(language_name)
+      Rouge::Lexer.find_fancy(@language)
     end
 
     def highlight_text(text, continue: true, plain: false)