From 63731425130b6b4ca96753348a6edf0d0b094648 Mon Sep 17 00:00:00 2001
From: Frederick Cheung <frederick.cheung@gmail.com>
Date: Fri, 10 Jul 2020 12:56:40 +0100
Subject: [PATCH] Fix memory leak caused by caching all unique paths seen

This optimisation was introduced in #2002. If an api's paths include
an id in the path then this cache can grow in an unbounded manner.
---
 CHANGELOG.md        |  1 +
 lib/grape/router.rb | 18 +++++-------------
 2 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c50d10928d..6af761ee6f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 * [#2060](https://github.com/ruby-grape/grape/pull/2060): Drop support for Ruby 2.4 - [@dblock](https://github.com/dblock).
 * [#2060](https://github.com/ruby-grape/grape/pull/2060): Upgraded Rubocop to 0.84.0 - [@dblock](https://github.com/dblock).
 * [#2077](https://github.com/ruby-grape/grape/pull/2077): Simplify logic for defining declared params - [@dnesteryuk](https://github.com/dnesteryuk).
+* [#2084](https://github.com/ruby-grape/grape/pull/2084): Fix memory leak in path normalization- [@fcheung](https://github.com/fcheung).
 * Your contribution here.
 
 #### Fixes
diff --git a/lib/grape/router.rb b/lib/grape/router.rb
index f2b8cf2416..c5d9e96422 100644
--- a/lib/grape/router.rb
+++ b/lib/grape/router.rb
@@ -7,20 +7,12 @@ module Grape
   class Router
     attr_reader :map, :compiled
 
-    class NormalizePathCache < Grape::Util::Cache
-      def initialize
-        @cache = Hash.new do |h, path|
-          normalized_path = +"/#{path}"
-          normalized_path.squeeze!('/')
-          normalized_path.sub!(%r{/+\Z}, '')
-          normalized_path = '/' if normalized_path.empty?
-          h[path] = -normalized_path
-        end
-      end
-    end
-
     def self.normalize_path(path)
-      NormalizePathCache[path]
+      path = +"/#{path}"
+      path.squeeze!('/')
+      path.sub!(%r{/+\Z}, '')
+      path = '/' if path == ''
+      path
     end
 
     def self.supported_methods