Adds requests/second rate limiter

lib/rack/throttle/second.rb

@@ -0,0 +1,42 @@
+module Rack; module Throttle
+  ##
+  # This rate limiter strategy throttles the application by defining a
+  # maximum number of allowed HTTP requests per second (by default, 1
+  # request per second.
+  #
+  # Note that this strategy doesn't use a sliding time window, but rather
+  # tracks requests per distinct second. This means that the throttling
+  # counter is reset every second.
+  #
+  # @example Allowing up to 1 request/second
+  #   use Rack::Throttle::Second
+  #
+  # @example Allowing up to 100 requests per second
+  #   use Rack::Throttle::Second, :max => 100
+  #
+  class Second < TimeWindow
+    ##
+    # @param  [#call]                  app
+    # @param  [Hash{Symbol => Object}] options
+    # @option options [Integer] :max   (1)
+    def initialize(app, options = {})
+      super
+    end
+
+    ##
+    def max_per_second
+      @max_per_hour ||= options[:max_per_second] || options[:max] || 1
+    end
+
+    alias_method :max_per_window, :max_per_second
+
+    protected
+
+    ##
+    # @param  [Rack::Request] request
+    # @return [String]
+    def cache_key(request)
+      [super, Time.now.strftime('%Y-%m-%dT%H:%S')].join(':')
+    end
+  end
+end; end