Merge branch 'further-blame-improvements' into 'master'

Reducing variable instantiations in blame processing

See merge request gitlab-org/gitlab!55973

lib/gitlab/blame.rb

@@ -19,16 +19,14 @@ module Gitlab
         commit = Commit.new(commit, project)
         commit.lazy_author # preload author
 
-        sha = commit.sha
-        if prev_sha != sha
+        if prev_sha != commit.sha
           groups << current_group if current_group
           current_group = { commit: commit, lines: [] }
         end
 
-        line = highlighted_lines[i].html_safe if highlight
-        current_group[:lines] << line
+        current_group[:lines] << (highlight ? highlighted_lines[i].html_safe : line)
 
-        prev_sha = sha
+        prev_sha = commit.sha
         i += 1
       end
       groups << current_group if current_group

lib/gitlab/git/blame.rb

@@ -38,9 +38,11 @@ module Gitlab
           if line[0, 1] == "\t"
             lines << line[1, line.size]
           elsif m = /^(\w{40}) (\d+) (\d+)/.match(line)
-            commit_id, old_lineno, lineno = m[1], m[2].to_i, m[3].to_i
+            # Removed these instantiations for performance but keeping them for reference:
+            # commit_id, old_lineno, lineno = m[1], m[2].to_i, m[3].to_i
+            commit_id = m[1]
             commits[commit_id] = nil unless commits.key?(commit_id)
-            info[lineno] = [commit_id, old_lineno]
+            info[m[3].to_i] = [commit_id, m[2].to_i]
           end
         end
 
@@ -50,8 +52,7 @@ module Gitlab
 
         # get it together
         info.sort.each do |lineno, (commit_id, old_lineno)|
-          commit = commits[commit_id]
-          final << BlameLine.new(lineno, old_lineno, commit, lines[lineno - 1])
+          final << BlameLine.new(lineno, old_lineno, commits[commit_id], lines[lineno - 1])
         end
 
         @lines = final