ruby rework with contact form

lib/rate_limit.rb

@@ -0,0 +1,31 @@
+require 'thread'
+
+class RateLimit
+  def initialize(limit:, window:)
+    @limit = limit
+    @window = window
+    @hits = Hash.new { |h, k| h[k] = [] }
+    @mutex = Mutex.new
+  end
+
+  def allow?(key)
+    now = Time.now.to_i
+    @mutex.synchronize do
+      @hits[key].reject! { |t| t < now - @window }
+      if @hits[key].size >= @limit
+        false
+      else
+        @hits[key] << now
+        true
+      end
+    end
+  end
+
+  def sweep!
+    cutoff = Time.now.to_i - @window
+    @mutex.synchronize do
+      @hits.each_value { |arr| arr.reject! { |t| t < cutoff } }
+      @hits.delete_if { |_, arr| arr.empty? }
+    end
+  end
+end