Merge branch 'refactor_compare' into 'master'

Refactor Compare logic

Updated gitlab_git to version 5.4.0.
Fixes MR diff download link in case of huge diff.
Fixes #1026

Gemfile

@@ -29,7 +29,7 @@ gem 'omniauth-github'
 
 # Extracting information from a git repository
 # Provide access to Gitlab::Git library
-gem "gitlab_git", '~> 5.3.0'
+gem "gitlab_git", '~> 5.4.0'
 
 # Ruby/Rack Git Smart-HTTP Server Handler
 gem 'gitlab-grack', '~> 2.0.0.pre', require: 'grack'

Gemfile.lock

@@ -177,7 +177,7 @@ GEM
       charlock_holmes (~> 0.6.6)
       escape_utils (~> 0.2.4)
       mime-types (~> 1.19)
-    gitlab_git (5.3.0)
+    gitlab_git (5.4.0)
       activesupport (~> 4.0.0)
       charlock_holmes (~> 0.6.9)
       gitlab-grit (~> 2.6.1)
@@ -579,7 +579,7 @@ DEPENDENCIES
   gitlab-gollum-lib (~> 1.1.0)
   gitlab-grack (~> 2.0.0.pre)
   gitlab-linguist (~> 3.0.0)
-  gitlab_git (~> 5.3.0)
+  gitlab_git (~> 5.4.0)
   gitlab_meta (= 6.0)
   gitlab_omniauth-ldap (= 1.0.4)
   gon (~> 5.0.0)

app/controllers/projects/compare_controller.rb

@@ -15,11 +15,7 @@ class Projects::CompareController < Projects::ApplicationController
     @diffs         = compare.diffs
     @refs_are_same = compare.same
     @line_notes    = []
-
-    if @diffs == [Gitlab::Git::Diff::BROKEN_DIFF]
-      @diffs = []
-      @timeout = true
-    end
+    @timeout       = compare.timeout
 
     diff_line_count = Commit::diff_line_count(@diffs)
     @suppress_diff = Commit::diff_suppress?(@diffs, diff_line_count) && !params[:force_show_diff]

app/mailers/emails/projects.rb

@@ -17,6 +17,7 @@ module Emails
     def repository_push_email(project_id, recipient, author_id, branch, compare)
       @project = Project.find(project_id)
       @author  = User.find(author_id)
+      @compare = compare
       @commits = Commit.decorate(compare.commits)
       @diffs   = compare.diffs
       @branch  = branch

app/models/merge_request_diff.rb

@@ -148,13 +148,11 @@ class MergeRequestDiff < ActiveRecord::Base
               Gitlab::Git::Diff.between(repository, source_branch, target_branch)
             end
 
-    if diffs == broken_diffs
-      self.state = :timeout
-      diffs = []
-    end
-
     diffs ||= []
     diffs
+  rescue Gitlab::Git::Diff::TimeoutError => ex
+    self.state = :timeout
+    diffs = []
   end
 
   def repository

app/views/notify/repository_push_email.html.haml

@@ -21,3 +21,8 @@
     %pre
       = diff.diff
     %br
+
+- if @compare.timeout
+  %h5 Huge diff. To prevent performance issues it was hidden
+- elsif @compare.commits_over_limit?
+  %h5 Diff for big amount of commits is disabled

app/views/notify/repository_push_email.text.haml

@@ -18,3 +18,8 @@ Diff:
     = diff.new_path || diff.old_path
   \=====================================
   = diff.diff
+\
+- if @compare.timeout
+  Huge diff. To prevent performance issues it was hidden
+- elsif @compare.commits_over_limit?
+  Diff for big amount of commits is disabled

app/views/projects/merge_requests/show/_diffs.html.haml

@@ -3,8 +3,10 @@
 - elsif @merge_request_diff.empty?
   %h4.nothing_here_message Nothing to merge from #{@merge_request.source_branch} into #{@merge_request.target_branch}
 - else
-  %h4.nothing_here_message
-    Can't load diff.
+  .bs-callout.bs-callout-warning
+    %h4
+      Diff for this comparison is extremely large.
+    %p
       You can
-    = link_to "download it", project_merge_request_path(@merge_request.source_project, @merge_request), format: :diff, class: "vlink"
+      = link_to "download it", project_merge_request_path(@merge_request.source_project, @merge_request, format: :diff), class: "vlink"
       instead.

app/workers/emails_on_push_worker.rb

@@ -13,13 +13,13 @@ class EmailsOnPushWorker
       return true
     end
 
-    compare = Gitlab::Git::Compare.new(project.repository.raw_repository, before_sha, after_sha)
+    compare = Gitlab::Git::Compare.new(project.repository.raw_repository, before_sha, after_sha, MergeRequestDiff::COMMITS_SAFE_SIZE)
 
     # Do not send emails if git compare failed
     return false unless compare && compare.commits.present?
 
     recipients.split(" ").each do |recipient|
-      Notify.delay.repository_push_email(project_id, recipient, author_id, branch, compare)
+      Notify.repository_push_email(project_id, recipient, author_id, branch, compare).deliver
     end
   end
 end