From 137d951f7579038f088b0a9a724f1c25b5e23c4d Mon Sep 17 00:00:00 2001
From: Jean-Baptiste Barth <jeanbaptiste.barth@gmail.com>
Date: Wed, 27 Aug 2014 19:18:13 +0200
Subject: [PATCH] Optimize committers/users map retrieval for statistic graphs
 (#13487).

---
 app/models/repository.rb | 36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/app/models/repository.rb b/app/models/repository.rb
index 55cdb6d..9f50c63 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -414,17 +414,35 @@ class Repository < ActiveRecord::Base
   # Notes:
   # - this hash honnors the users mapping defined for the repository
   def stats_by_author
-    commits_by_author = Changeset.where("repository_id = ?", id).group(:committer).count
-    commits_by_author.to_a.sort! {|x, y| x.last <=> y.last}
-
-    changes_by_author = Change.joins(:changeset).where("#{Changeset.table_name}.repository_id = ?", id).group(:committer).count
-    h = changes_by_author.inject({}) {|o, i| o[i.first] = i.last; o}
+    commits = Changeset.where("repository_id = ?", id)
+                       .select("committer, user_id, count(*) as count")
+                       .group("committer, user_id")
+
+    #TODO: restore ordering ; this line probably never worked
+    #commits.to_a.sort! {|x, y| x.last <=> y.last}
+
+    changes = Change.joins(:changeset)
+                    .where("#{Changeset.table_name}.repository_id = ?", id)
+                    .select("committer, user_id, count(*) as count")
+                    .group("committer, user_id")
+
+    user_ids = changesets.map(&:user_id).compact.uniq
+    authors_names = User.where(:id => user_ids).inject({}) do |memo, user|
+      memo[user.id] = user.to_s
+      memo
+    end
 
-    commits_by_author.inject({}) do |hash, (name, commits_count)|
-      mapped_name = (find_committer_user(name) || name).to_s
+    (commits + changes).inject({}) do |hash, element|
+      mapped_name = element.committer
+      if username = authors_names[element.user_id.to_i]
+        mapped_name = username
+      end
       hash[mapped_name] ||= { :commits_count => 0, :changes_count => 0 }
-      hash[mapped_name][:commits_count] += commits_count
-      hash[mapped_name][:changes_count] += h[name] || 0
+      if element.is_a?(Changeset)
+        hash[mapped_name][:commits_count] += element.count.to_i
+      else
+        hash[mapped_name][:changes_count] += element.count.to_i
+      end
       hash
     end
   end
-- 
1.8.5.2 (Apple Git-48)