Add cache refresh rate

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+## 1.6.4
+
+- Add `cache_refresh_period` to allow for cache refresh after a period of time. (#579)
+
 ## 1.6.3
 
 - Split the `with_deferred_parent_expiration` and `with_deferred_parent_expiration`. (#578)

Gemfile.lock

@@ -93,6 +93,8 @@ GEM
 PLATFORMS
   arm64-darwin-22
   arm64-darwin-23
+  arm64-darwin-24
+  x64-mingw-ucrt
   x86_64-linux
 
 DEPENDENCIES

lib/identity_cache/cache_fetcher.rb

@@ -1,8 +1,12 @@
 # frozen_string_literal: true
 
+require "time"
 require "securerandom"
 
 module IdentityCache
+  mattr_accessor :cache_refresh_period
+  self.cache_refresh_period = 60
+
   class CacheFetcher
     attr_accessor :cache_backend
 
@@ -93,7 +97,10 @@ def fetch_without_fill_lock(key)
       data = nil
       upsert(key) do |value|
         value = nil if value == IdentityCache::DELETED || FillLock.cache_value?(value)
-        unless value.nil?
+        unless value.nil? ||
+            (value&.is_a?(Hash) &&
+              value[:cached_at] &&
+              ((Time.now - value[:cached_at]) / 60).round > IdentityCache.cache_refresh_period)
           return value
         end
 
@@ -316,6 +323,10 @@ def add_multi(keys)
     def add(key, value, expiration_options = EMPTY_HASH)
       return false unless IdentityCache.should_fill_cache?
 
+      if value&.is_a?(Hash)
+        value.merge(cached_at: Time.now.to_s)
+      end
+
       @cache_backend.write(key, value, { unless_exist: true, **expiration_options })
     end
   end

test/cache_fetcher_test.rb

@@ -177,3 +177,31 @@ def other_cache_fetcher
     @other_cache_fetcher ||= IdentityCache::CacheFetcher.new(backend)
   end
 end
+
+def test_fetch_without_fill_lock_with_stale_cached_data
+  identity_cache = IdentityCache
+  identity_cache.cache_refresh_period = 60
+  stale_time = Time.now - (identity_cache.cache_refresh_period + 1) * 60
+  backend.write(key, { cached_at: stale_time, data: :old_data })
+  assert_memcache_operations(2) do
+    assert_equal(:new_data, cache_fetcher.fetch_without_fill_lock(key) { :new_data })
+  end
+end
+
+def test_fetch_without_fill_lock_with_fresh_cached_data
+  identity_cache = IdentityCache
+  identity_cache.cache_refresh_period = 60
+  fresh_time = Time.now - (identity_cache.cache_refresh_period - 1) * 60
+  cached_data = { cached_at: fresh_time, data: :fresh_data }
+  backend.write(key, cached_data)
+  assert_memcache_operations(1) do
+    assert_equal(cached_data, cache_fetcher.fetch_without_fill_lock(key) { :new_data })
+  end
+end
+
+def test_fetch_without_fill_lock_with_non_hash_value
+  backend.write(key, "string_value")
+  assert_memcache_operations(1) do
+    assert_equal("string_value", cache_fetcher.fetch_without_fill_lock(key) { :new_data })
+  end
+end

test/helpers/database_connection.rb

@@ -79,6 +79,7 @@ def create_tables
       "host" => ENV["MYSQL_HOST"] || "127.0.0.1",
       "username" => "root",
       "port" => ENV["MYSQL_PORT"] ? Integer(ENV["MYSQL_PORT"]) : 3306,
+      "password" => ENV["MYSQL_PASSWORD"] || "my-secret-pw",
     },
     "postgresql" => {
       "adapter" => "postgresql",