From ab91f1226f9dc99725e10323c0ea319f335204b3 Mon Sep 17 00:00:00 2001
From: Yorick Peterse <yorickpeterse@gmail.com>
Date: Tue, 14 Jun 2016 14:35:25 +0200
Subject: [PATCH] Filter out classes without names in the sampler

We can't do a lot with classes without names as we can't filter by them,
have no idea where they come from, etc. As such it's best to just ignore
these.
---
 lib/gitlab/metrics/sampler.rb           |  6 +++++-
 spec/lib/gitlab/metrics/sampler_spec.rb | 25 ++++++++++++++++++-------
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/lib/gitlab/metrics/sampler.rb b/lib/gitlab/metrics/sampler.rb
index fc709222a9b..0000450d9bb 100644
--- a/lib/gitlab/metrics/sampler.rb
+++ b/lib/gitlab/metrics/sampler.rb
@@ -66,7 +66,11 @@ module Gitlab
         def sample_objects
           sample = Allocations.to_hash
           counts = sample.each_with_object({}) do |(klass, count), hash|
-            hash[klass.name] = count
+            name = klass.name
+
+            next unless name
+
+            hash[name] = count
           end
 
           # Symbols aren't allocated so we'll need to add those manually.
diff --git a/spec/lib/gitlab/metrics/sampler_spec.rb b/spec/lib/gitlab/metrics/sampler_spec.rb
index 59db127674a..1ab923b58cf 100644
--- a/spec/lib/gitlab/metrics/sampler_spec.rb
+++ b/spec/lib/gitlab/metrics/sampler_spec.rb
@@ -72,14 +72,25 @@ describe Gitlab::Metrics::Sampler do
     end
   end
 
-  describe '#sample_objects' do
-    it 'adds a metric containing the amount of allocated objects' do
-      expect(sampler).to receive(:add_metric).
-        with(/object_counts/, an_instance_of(Hash), an_instance_of(Hash)).
-        at_least(:once).
-        and_call_original
+  if Gitlab::Metrics.mri?
+    describe '#sample_objects' do
+      it 'adds a metric containing the amount of allocated objects' do
+        expect(sampler).to receive(:add_metric).
+          with(/object_counts/, an_instance_of(Hash), an_instance_of(Hash)).
+          at_least(:once).
+          and_call_original
 
-      sampler.sample_objects
+        sampler.sample_objects
+      end
+
+      it 'ignores classes without a name' do
+        expect(Allocations).to receive(:to_hash).and_return({ Class.new => 4 })
+
+        expect(sampler).not_to receive(:add_metric).
+          with('object_counts', an_instance_of(Hash), type: nil)
+
+        sampler.sample_objects
+      end
     end
   end