3 files changed, 69 insertions, 0 deletions

diff --git a/lib/gitlab/action_rate_limiter.rb b/lib/gitlab/action_rate_limiter.rb
new file mode 100644
index 00000000000..4cd3bdefda3
--- /dev/null
+++ b/lib/gitlab/action_rate_limiter.rb
@@ -0,0 +1,47 @@
+module Gitlab
+  # This class implements a simple rate limiter that can be used to throttle
+  # certain actions. Unlike Rack Attack and Rack::Throttle, which operate at
+  # the middleware level, this can be used at the controller level.
+  class ActionRateLimiter
+    TIME_TO_EXPIRE = 60 # 1 min
+
+    attr_accessor :action, :expiry_time
+
+    def initialize(action:, expiry_time: TIME_TO_EXPIRE)
+      @action = action
+      @expiry_time = expiry_time
+    end
+
+    # Increments the given cache key and increments the value by 1 with the
+    # given expiration time. Returns the incremented value.
+    #
+    # key - An array of ActiveRecord instances
+    def increment(key)
+      value = 0
+
+      Gitlab::Redis::Cache.with do |redis|
+        cache_key = action_key(key)
+        value = redis.incr(cache_key)
+        redis.expire(cache_key, expiry_time) if value == 1
+      end
+
+      value
+    end
+
+    # Increments the given key and returns true if the action should
+    # be throttled.
+    #
+    # key - An array of ActiveRecord instances
+    # threshold_value - The maximum number of times this action should occur in the given time interval
+    def throttled?(key, threshold_value)
+      self.increment(key) > threshold_value
+    end
+
+    private
+
+    def action_key(key)
+      serialized = key.map { |obj| "#{obj.class.model_name.to_s.underscore}:#{obj.id}" }.join(":")
+      "action_rate_limiter:#{action}:#{serialized}"
+    end
+  end
+end
diff --git a/lib/gitlab/git/commit.rb b/lib/gitlab/git/commit.rb
index e90b158fb34..145721dea76 100644
--- a/lib/gitlab/git/commit.rb
+++ b/lib/gitlab/git/commit.rb
@@ -228,6 +228,19 @@ module Gitlab
             end
           end
         end
+
+        # Only to be used when the object ids will not necessarily have a
+        # relation to each other. The last 10 commits for a branch for example,
+        # should go through .where
+        def batch_by_oid(repo, oids)
+          repo.gitaly_migrate(:list_commits_by_oid) do |is_enabled|
+            if is_enabled
+              repo.gitaly_commit_client.list_commits_by_oid(oids)
+            else
+              oids.map { |oid| find(repo, oid) }.compact
+            end
+          end
+        end
       end
 
       def initialize(repository, raw_commit, head = nil)
diff --git a/lib/gitlab/gitaly_client/commit_service.rb b/lib/gitlab/gitaly_client/commit_service.rb
index 7985f5b5457..fb3e27770b4 100644
--- a/lib/gitlab/gitaly_client/commit_service.rb
+++ b/lib/gitlab/gitaly_client/commit_service.rb
@@ -169,6 +169,15 @@ module Gitlab
         consume_commits_response(response)
       end
 
+      def list_commits_by_oid(oids)
+        request = Gitaly::ListCommitsByOidRequest.new(repository: @gitaly_repo, oid: oids)
+
+        response = GitalyClient.call(@repository.storage, :commit_service, :list_commits_by_oid, request, timeout: GitalyClient.medium_timeout)
+        consume_commits_response(response)
+      rescue GRPC::Unknown # If no repository is found, happens mainly during testing
+        []
+      end
+
       def commits_by_message(query, revision: '', path: '', limit: 1000, offset: 0)
         request = Gitaly::CommitsByMessageRequest.new(
           repository: @gitaly_repo,