Properly handle bigger files

CHANGELOG

@@ -11,6 +11,7 @@ v 8.8.0 (unreleased)
   - Allow "NEWS" and "CHANGES" as alternative names for CHANGELOG. !3768 (Connor Shea)
   - Added button to toggle whitespaces changes on diff view
   - Backport GitLab Enterprise support from EE
+  - Files over 5MB can only be viewed in their raw form, files over 1MB without highlighting !3718
 
 v 8.7.1 (unreleased)
   - Throttle the update of `project.last_activity_at` to 1 minute. !3848

app/helpers/blob_helper.rb

@@ -3,8 +3,8 @@ module BlobHelper
     Gitlab::Highlight.new(blob_name, blob_content, nowrap: nowrap)
   end
 
-  def highlight(blob_name, blob_content, nowrap: false)
-    Gitlab::Highlight.highlight(blob_name, blob_content, nowrap: nowrap)
+  def highlight(blob_name, blob_content, nowrap: false, plain: false)
+    Gitlab::Highlight.highlight(blob_name, blob_content, nowrap: nowrap, plain: plain)
   end
 
   def no_highlight_files

app/models/blob.rb

@@ -19,6 +19,14 @@ class Blob < SimpleDelegator
     new(blob)
   end
 
+  def no_highlighting?
+    size && size > 1.megabyte
+  end
+
+  def only_display_raw?
+    size && size > 5.megabytes
+  end
+
   def svg?
     text? && language && language.name == 'SVG'
   end

app/models/snippet.rb

@@ -112,6 +112,10 @@ class Snippet < ActiveRecord::Base
     visibility_level
   end
 
+  def no_highlighting?
+    content.lines.count > 1000
+  end
+
   class << self
     # Searches for snippets with a matching title or file name.
     #

app/views/projects/blob/_text.html.haml

-- blob.load_all_data!(@repository)
-- if markup?(blob.name)
+- if blob.only_display_raw?
+  .file-content.code
+    .nothing-here-block
+      File too large, you can
+      = succeed '.' do
+        = link_to 'view the raw file', namespace_project_raw_path(@project.namespace, @project, @id), target: '_blank'
+
+- else
+  - blob.load_all_data!(@repository)
+
+  - if markup?(blob.name)
     .file-content.wiki
       = render_markup(blob.name, blob.data)
-- else
-  - unless blob.empty?
-    = render 'shared/file_highlight', blob: blob
   - else
+    - if blob.empty?
       .file-content.code
         .nothing-here-block Empty file
+    - else
+      = render 'shared/file_highlight', blob: blob

app/views/shared/_file_highlight.html.haml

 .file-content.code.js-syntax-highlight
   .line-numbers
     - if blob.data.present?
+      - link_icon = icon('link')
       - blob.data.each_line.each_with_index do |_, index|
         - offset = defined?(first_line_number) ? first_line_number : 1
         - i = index + offset
         -# We're not using `link_to` because it is too slow once we get to thousands of lines.
         %a.diff-line-num{href: "#L#{i}", id: "L#{i}", 'data-line-number' => i}
-          %i.fa.fa-link
+          = link_icon
           = i
   .blob-content{data: {blob_id: blob.id}}
-    = highlight(blob.name, blob.data)
+    = highlight(blob.name, blob.data, plain: blob.no_highlighting?)

lib/gitlab/highlight.rb

 module Gitlab
   class Highlight
-    def self.highlight(blob_name, blob_content, nowrap: true)
-      new(blob_name, blob_content, nowrap: nowrap).highlight(blob_content, continue: false)
+    def self.highlight(blob_name, blob_content, nowrap: true, plain: false)
+      new(blob_name, blob_content, nowrap: nowrap).
+        highlight(blob_content, continue: false, plain: plain)
     end
 
     def self.highlight_lines(repository, ref, file_name)
@@ -17,8 +18,12 @@ module Gitlab
       @lexer = Rouge::Lexer.guess(filename: blob_name, source: blob_content).new rescue Rouge::Lexers::PlainText
     end
 
-    def highlight(text, continue: true)
+    def highlight(text, continue: true, plain: false)
+      if plain
+        @formatter.format(Rouge::Lexers::PlainText.lex(text)).html_safe
+      else
         @formatter.format(@lexer.lex(text, continue: continue)).html_safe
+      end
     rescue
       @formatter.format(Rouge::Lexers::PlainText.lex(text)).html_safe
     end