Merge branch '64251-redis-set-cache-mark-2' into 'master'

Re-introduce the Redis set cache for branch and tag names - but don't enable it yet

See merge request gitlab-org/gitlab-ce!32412

3 files changed, 96 insertions, 2 deletions

diff --git a/spec/lib/gitlab/repository_cache_adapter_spec.rb b/spec/lib/gitlab/repository_cache_adapter_spec.rb
index 808eb865a21..fd1338b55a6 100644
--- a/spec/lib/gitlab/repository_cache_adapter_spec.rb
+++ b/spec/lib/gitlab/repository_cache_adapter_spec.rb
@@ -6,6 +6,7 @@ describe Gitlab::RepositoryCacheAdapter do
   let(:project) { create(:project, :repository) }
   let(:repository) { project.repository }
   let(:cache) { repository.send(:cache) }
+  let(:redis_set_cache) { repository.send(:redis_set_cache) }
 
   describe '#cache_method_output', :use_clean_rails_memory_store_caching do
     let(:fallback) { 10 }
@@ -208,9 +209,11 @@ describe Gitlab::RepositoryCacheAdapter do
   describe '#expire_method_caches' do
     it 'expires the caches of the given methods' do
       expect(cache).to receive(:expire).with(:rendered_readme)
-      expect(cache).to receive(:expire).with(:gitignore)
+      expect(cache).to receive(:expire).with(:branch_names)
+      expect(redis_set_cache).to receive(:expire).with(:rendered_readme)
+      expect(redis_set_cache).to receive(:expire).with(:branch_names)
 
-      repository.expire_method_caches(%i(rendered_readme gitignore))
+      repository.expire_method_caches(%i(rendered_readme branch_names))
     end
 
     it 'does not expire caches for non-existent methods' do
diff --git a/spec/lib/gitlab/repository_set_cache_spec.rb b/spec/lib/gitlab/repository_set_cache_spec.rb
new file mode 100644
index 00000000000..87e51f801e5
--- /dev/null
+++ b/spec/lib/gitlab/repository_set_cache_spec.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::RepositorySetCache, :clean_gitlab_redis_cache do
+  let(:project) { create(:project) }
+  let(:repository) { project.repository }
+  let(:namespace) { "#{repository.full_path}:#{project.id}" }
+  let(:cache) { described_class.new(repository) }
+
+  describe '#cache_key' do
+    subject { cache.cache_key(:foo) }
+
+    it 'includes the namespace' do
+      is_expected.to eq("foo:#{namespace}:set")
+    end
+
+    context 'with a given namespace' do
+      let(:extra_namespace) { 'my:data' }
+      let(:cache) { described_class.new(repository, extra_namespace: extra_namespace) }
+
+      it 'includes the full namespace' do
+        is_expected.to eq("foo:#{namespace}:#{extra_namespace}:set")
+      end
+    end
+  end
+
+  describe '#expire' do
+    it 'expires the given key from the cache' do
+      cache.write(:foo, ['value'])
+
+      expect(cache.read(:foo)).to contain_exactly('value')
+      expect(cache.expire(:foo)).to eq(1)
+      expect(cache.read(:foo)).to be_empty
+    end
+  end
+
+  describe '#exist?' do
+    it 'checks whether the key exists' do
+      expect(cache.exist?(:foo)).to be(false)
+
+      cache.write(:foo, ['value'])
+
+      expect(cache.exist?(:foo)).to be(true)
+    end
+  end
+
+  describe '#fetch' do
+    let(:blk) { -> { ['block value'] } }
+
+    subject { cache.fetch(:foo, &blk) }
+
+    it 'fetches the key from the cache when filled' do
+      cache.write(:foo, ['value'])
+
+      is_expected.to contain_exactly('value')
+    end
+
+    it 'writes the value of the provided block when empty' do
+      cache.expire(:foo)
+
+      is_expected.to contain_exactly('block value')
+      expect(cache.read(:foo)).to contain_exactly('block value')
+    end
+  end
+
+  describe '#include?' do
+    it 'checks inclusion in the Redis set' do
+      cache.write(:foo, ['value'])
+
+      expect(cache.include?(:foo, 'value')).to be(true)
+      expect(cache.include?(:foo, 'bar')).to be(false)
+    end
+  end
+end
diff --git a/spec/lib/gitlab/utils/strong_memoize_spec.rb b/spec/lib/gitlab/utils/strong_memoize_spec.rb
index 26baaf873a8..624e799c5e9 100644
--- a/spec/lib/gitlab/utils/strong_memoize_spec.rb
+++ b/spec/lib/gitlab/utils/strong_memoize_spec.rb
@@ -52,6 +52,22 @@ describe Gitlab::Utils::StrongMemoize do
     end
   end
 
+  describe '#strong_memoized?' do
+    let(:value) { :anything }
+
+    subject { object.strong_memoized?(:method_name) }
+
+    it 'returns false if the value is uncached' do
+      is_expected.to be(false)
+    end
+
+    it 'returns true if the value is cached' do
+      object.method_name
+
+      is_expected.to be(true)
+    end
+  end
+
   describe '#clear_memoization' do
     let(:value) { 'mepmep' }