Merge branch 'parallel_diff_refactor' into 'master'

Parallel diff refactor

Refactor side-by-side diff to remove code duplication.

Base the side-by-side diff on inline diff code.

In first iteration:

1. commenting on the side-by-side diff is not possible
1. no expanding of the surrounding code

See merge request !1066

5 files changed, 151 insertions, 83 deletions

diff --git a/lib/gitlab/diff/file.rb b/lib/gitlab/diff/file.rb
new file mode 100644
index 00000000000..19a1198c68c
--- /dev/null
+++ b/lib/gitlab/diff/file.rb
@@ -0,0 +1,49 @@
+module Gitlab
+  module Diff
+    class File
+      attr_reader :diff
+
+      delegate :new_file, :deleted_file, :renamed_file,
+        :old_path, :new_path, to: :diff, prefix: false
+
+      def initialize(diff)
+        @diff = diff
+      end
+
+      # Array of Gitlab::DIff::Line objects
+      def diff_lines
+        @lines ||= parser.parse(raw_diff.lines)
+      end
+
+      def mode_changed?
+        !!(diff.a_mode && diff.b_mode && diff.a_mode != diff.b_mode)
+      end
+
+      def parser
+        Gitlab::Diff::Parser.new
+      end
+
+      def raw_diff
+        diff.diff
+      end
+
+      def next_line(index)
+        diff_lines[index + 1]
+      end
+
+      def prev_line(index)
+        if index > 0
+          diff_lines[index - 1]
+        end
+      end
+
+      def file_path
+        if diff.new_path.present?
+          diff.new_path
+        elsif diff.old_path.present?
+          diff.old_path
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/diff/line.rb b/lib/gitlab/diff/line.rb
new file mode 100644
index 00000000000..8ac1b15e88a
--- /dev/null
+++ b/lib/gitlab/diff/line.rb
@@ -0,0 +1,12 @@
+module Gitlab
+  module Diff
+    class Line
+      attr_reader :type, :text, :index, :old_pos, :new_pos
+
+      def initialize(text, type, index, old_pos, new_pos)
+        @text, @type, @index = text, type, index
+        @old_pos, @new_pos = old_pos, new_pos
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/diff/line_code.rb b/lib/gitlab/diff/line_code.rb
new file mode 100644
index 00000000000..f3578ab3d35
--- /dev/null
+++ b/lib/gitlab/diff/line_code.rb
@@ -0,0 +1,9 @@
+module Gitlab
+  module Diff
+    class LineCode
+      def self.generate(file_path, new_line_position, old_line_position)
+        "#{Digest::SHA1.hexdigest(file_path)}_#{old_line_position}_#{new_line_position}"
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/diff/parser.rb b/lib/gitlab/diff/parser.rb
new file mode 100644
index 00000000000..9d6309954a4
--- /dev/null
+++ b/lib/gitlab/diff/parser.rb
@@ -0,0 +1,81 @@
+module Gitlab
+  module Diff
+    class Parser
+      include Enumerable
+
+      def parse(lines)
+        @lines = lines,
+        lines_obj = []
+        line_obj_index = 0
+        line_old = 1
+        line_new = 1
+        type = nil
+
+        lines_arr = ::Gitlab::InlineDiff.processing lines
+
+        lines_arr.each do |line|
+          raw_line = line.dup
+
+          next if filename?(line)
+
+          full_line = html_escape(line.gsub(/\n/, ''))
+          full_line = ::Gitlab::InlineDiff.replace_markers full_line
+
+          if line.match(/^@@ -/)
+            type = "match"
+
+            line_old = line.match(/\-[0-9]*/)[0].to_i.abs rescue 0
+            line_new = line.match(/\+[0-9]*/)[0].to_i.abs rescue 0
+
+            next if line_old == 1 && line_new == 1 #top of file
+            lines_obj << Gitlab::Diff::Line.new(full_line, type, line_obj_index, line_old, line_new)
+            line_obj_index += 1
+            next
+          else
+            type = identification_type(line)
+            lines_obj << Gitlab::Diff::Line.new(full_line, type, line_obj_index, line_old, line_new)
+            line_obj_index += 1
+          end
+
+
+          if line[0] == "+"
+            line_new += 1
+          elsif line[0] == "-"
+            line_old += 1
+          else
+            line_new += 1
+            line_old += 1
+          end
+        end
+
+        lines_obj
+      end
+
+      def empty?
+        @lines.empty?
+      end
+
+      private
+
+      def filename?(line)
+        line.start_with?('--- /dev/null', '+++ /dev/null', '--- a', '+++ b',
+                         '--- /tmp/diffy', '+++ /tmp/diffy')
+      end
+
+      def identification_type(line)
+        if line[0] == "+"
+          "new"
+        elsif line[0] == "-"
+          "old"
+        else
+          nil
+        end
+      end
+
+      def html_escape str
+        replacements = { '&' => '&amp;', '>' => '&gt;', '<' => '&lt;', '"' => '&quot;', "'" => '&#39;' }
+          str.gsub(/[&"'><]/, replacements)
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/diff_parser.rb b/lib/gitlab/diff_parser.rb
deleted file mode 100644
index b244295027e..00000000000
--- a/lib/gitlab/diff_parser.rb
+++ /dev/null
@@ -1,83 +0,0 @@
-module Gitlab
-  class DiffParser
-    include Enumerable
-
-    attr_reader :lines, :new_path
-
-    def initialize(lines, new_path = '')
-      @lines = lines
-      @new_path = new_path
-    end
-
-    def each
-      line_old = 1
-      line_new = 1
-      type = nil
-
-      lines_arr = ::Gitlab::InlineDiff.processing lines
-      lines_arr.each do |line|
-        raw_line = line.dup
-
-        next if filename?(line)
-
-        full_line = html_escape(line.gsub(/\n/, ''))
-        full_line = ::Gitlab::InlineDiff.replace_markers full_line
-
-        if line.match(/^@@ -/)
-          type = "match"
-
-          line_old = line.match(/\-[0-9]*/)[0].to_i.abs rescue 0
-          line_new = line.match(/\+[0-9]*/)[0].to_i.abs rescue 0
-
-          next if line_old == 1 && line_new == 1 #top of file
-          yield(full_line, type, nil, line_new, line_old)
-          next
-        else
-          type = identification_type(line)
-          line_code = generate_line_code(new_path, line_new, line_old)
-          yield(full_line, type, line_code, line_new, line_old, raw_line)
-        end
-
-
-        if line[0] == "+"
-          line_new += 1
-        elsif line[0] == "-"
-          line_old += 1
-        else
-          line_new += 1
-          line_old += 1
-        end
-      end
-    end
-
-    def empty?
-      @lines.empty?
-    end
-
-    private
-
-    def filename?(line)
-      line.start_with?('--- /dev/null', '+++ /dev/null', '--- a', '+++ b',
-                       '--- /tmp/diffy', '+++ /tmp/diffy')
-    end
-
-    def identification_type(line)
-      if line[0] == "+"
-        "new"
-      elsif line[0] == "-"
-        "old"
-      else
-        nil
-      end
-    end
-
-    def generate_line_code(path, line_new, line_old)
-      "#{Digest::SHA1.hexdigest(path)}_#{line_old}_#{line_new}"
-    end
-
-    def html_escape str
-      replacements = { '&' => '&amp;', '>' => '&gt;', '<' => '&lt;', '"' => '&quot;', "'" => '&#39;' }
-        str.gsub(/[&"'><]/, replacements)
-    end
-  end
-end