Memory usage test for archive export

It is not included into the main test suite, because it has :performance tag.

One can run this test using command:
$ bin/rspec --tag performance spec/integration/export/memory_usage_spec.rb

This test creates additional fixtures set to speed up repeated runs.

spec/factories.rb

@@ -249,6 +249,15 @@ FactoryGirl.define do
     association(:post, factory: :status_message)
   end
 
+  factory :signed_comment, parent: :comment do
+    association(:parent, factory: :status_message)
+
+    after(:build) do |comment|
+      order = SignatureOrder.first || FactoryGirl.create(:signature_order)
+      comment.signature = FactoryGirl.build(:comment_signature, comment: comment, signature_order: order)
+    end
+  end
+
   factory(:notification, class: Notifications::AlsoCommented) do
     association :recipient, :factory => :user
     association :target, :factory => :comment

spec/integration/export/memory_usage_spec.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+# Memory usage methods are from: https://gist.github.com/pvdb/6240788
+
+# returns detailed information about the process memory usage (as recorded in the "/proc/$$/statm" proc fs file)
+def Process.statm
+  Hash[%i[size resident shared trs lrs drs dt].zip(open("/proc/#{Process.pid}/statm").read.split)]
+end
+
+# the real memory (resident set) size of the process (in 1_024 byte units, assuming a 4kB memory page size)
+def Process.rss
+  Process.statm[:resident].to_i * 4
+end
+
+describe Diaspora::Exporter do
+  context "on big profiles", :performance do
+    before :all do
+      if Post.count < 1000
+        # Force fixture rebuild
+        FileUtils.rm_f(Rails.root.join("tmp", "fixture_builder.yml"))
+      end
+
+      FixtureBuilder.configure do |fbuilder|
+        # rebuild fixtures automatically when these files change:
+        fbuilder.files_to_check += Dir[
+          "app/models/*.rb", "lib/**/*.rb", "spec/factories/*.rb", "spec/support/fixture_builder.rb"
+        ] - ["lib/diaspora/exporter.rb"]
+
+        # now declare objects
+        fbuilder.factory do
+          create_basic_users
+
+          1000.times {
+            FactoryGirl.create(:signed_comment, post: bob.person.posts.first)
+            FactoryGirl.create(:status_message, author: bob.person)
+            FactoryGirl.create(:comment, author: bob.person)
+            FactoryGirl.create(:contact, user: bob)
+            FactoryGirl.create(:participation, author: bob.person)
+          }
+        end
+      end
+    end
+
+    it "doesn't exceed sensible memory usage limit" do
+      json = Diaspora::Exporter.new(bob).execute
+      expect(json).not_to be_empty
+      expect(Process.rss).to be < 500 * 1024
+      puts "Process resident set size: #{Process.rss}"
+    end
+  end
+end

spec/support/fixture_builder.rb

@@ -1,47 +1,49 @@
 # frozen_string_literal: true
 
-FixtureBuilder.configure do |fbuilder|
+def create_basic_users
+  # Users
+  alice = FactoryGirl.create(:user_with_aspect, username: "alice", strip_exif: false)
+  alices_aspect = alice.aspects.where(name: "generic").first
 
+  eve = FactoryGirl.create(:user_with_aspect, username: "eve")
+  eves_aspect = eve.aspects.where(name: "generic").first
+
+  bob = FactoryGirl.create(:user_with_aspect, username: "bob")
+  bobs_aspect = bob.aspects.where(name: "generic").first
+  FactoryGirl.create(:aspect, name: "empty", user: bob)
+
+  connect_users(bob, bobs_aspect, alice, alices_aspect)
+  connect_users(bob, bobs_aspect, eve, eves_aspect)
+
+  # Set up friends - 2 local, 1 remote
+  local_luke = FactoryGirl.create(:user_with_aspect, username: "luke")
+  lukes_aspect = local_luke.aspects.where(name: "generic").first
+
+  local_leia = FactoryGirl.create(:user_with_aspect, username: "leia")
+  leias_aspect = local_leia.aspects.where(name: "generic").first
+
+  remote_raphael = FactoryGirl.create(:person, diaspora_handle: "raphael@remote.net")
+
+  connect_users_with_aspects(local_luke, local_leia)
+
+  local_leia.contacts.create(person: remote_raphael, aspects: [leias_aspect])
+  local_luke.contacts.create(person: remote_raphael, aspects: [lukes_aspect])
+
+  # Set up a follower
+  peter = FactoryGirl.create(:user_with_aspect, username: "peter")
+  peters_aspect = peter.aspects.where(name: "generic").first
+
+  peter.contacts.create!(person: alice.person, aspects: [peters_aspect], sharing: false, receiving: true)
+end
+
+FixtureBuilder.configure do |fbuilder|
   # rebuild fixtures automatically when these files change:
-  fbuilder.files_to_check += Dir["app/models/*.rb", "lib/**/*.rb",  "spec/factories/*.rb", "spec/support/fixture_builder.rb"]
+  fbuilder.files_to_check += Dir[
+    "app/models/*.rb", "lib/**/*.rb", "spec/factories/*.rb", "spec/support/fixture_builder.rb"
+  ] - ["lib/diaspora/exporter.rb"]
 
   # now declare objects
   fbuilder.factory do
-    # Users
+    create_basic_users
-    alice = FactoryGirl.create(:user_with_aspect, :username => "alice", :strip_exif => false)
+  end
-    alices_aspect = alice.aspects.where(:name => "generic").first
-
-    eve   = FactoryGirl.create(:user_with_aspect, :username => "eve")
-    eves_aspect = eve.aspects.where(:name => "generic").first
-
-    bob   = FactoryGirl.create(:user_with_aspect, :username => "bob")
-    bobs_aspect = bob.aspects.where(:name => "generic").first
-    FactoryGirl.create(:aspect, :name => "empty", :user => bob)
-
-    connect_users(bob, bobs_aspect, alice, alices_aspect)
-    connect_users(bob, bobs_aspect, eve, eves_aspect)
-
-    # Set up friends - 2 local, 1 remote
-    local_luke = FactoryGirl.create(:user_with_aspect, :username => "luke")
-    lukes_aspect = local_luke.aspects.where(:name => "generic").first
-
-    local_leia = FactoryGirl.create(:user_with_aspect, :username => "leia")
-    leias_aspect = local_leia.aspects.where(:name => "generic").first
-
-    remote_raphael = FactoryGirl.create(:person, :diaspora_handle => "raphael@remote.net")
-
-    connect_users_with_aspects(local_luke, local_leia)
-
-    local_leia.contacts.create(:person => remote_raphael, :aspects => [leias_aspect])
-    local_luke.contacts.create(:person => remote_raphael, :aspects => [lukes_aspect])
-
-    # Set up a follower
-    peter = FactoryGirl.create(:user_with_aspect, :username => "peter")
-    peters_aspect = peter.aspects.where(:name => "generic").first
-
-    peter.contacts.create!(:person => alice.person,
-                           :aspects => [peters_aspect],
-                           :sharing => false,
-                           :receiving => true)
-   end
 end