Add Bootsnap.unload_cache!

CHANGELOG.md

@@ -6,6 +6,9 @@
 
   People still using the classic autoloader might want to stick to `bootsnap 1.12`.
 
+* Add `Bootsnap.unload_cache!`. Applications can call it at the end of their boot sequence when they know
+  no more code will be loaded to reclaim a bit of memory.
+
 # 1.12.0
 
 * `bootsnap precompile` CLI will now also precompile `Rakefile` and `.rake` files.

lib/bootsnap.rb

@@ -76,6 +76,10 @@ def setup(
       )
     end
 
+    def self.unload_cache!
+      LoadPathCache.unload!
+    end
+
     def iseq_cache_supported?
       return @iseq_cache_supported if defined? @iseq_cache_supported
 

lib/bootsnap/load_path_cache.rb

@@ -21,8 +21,12 @@ module LoadPathCache
 
     CACHED_EXTENSIONS = DLEXT2 ? [DOT_RB, DLEXT, DLEXT2] : [DOT_RB, DLEXT]
 
+    @enabled = false
+
     class << self
-      attr_reader(:load_path_cache, :loaded_features_index)
+      attr_reader(:load_path_cache, :loaded_features_index, :enabled)
+      alias_method :enabled?, :enabled
+      remove_method(:enabled)
 
       def setup(cache_path:, development_mode:)
         unless supported?
@@ -35,10 +39,20 @@ def setup(cache_path:, development_mode:)
         @loaded_features_index = LoadedFeaturesIndex.new
 
         @load_path_cache = Cache.new(store, $LOAD_PATH, development_mode: development_mode)
+        @enabled = true
         require_relative("load_path_cache/core_ext/kernel_require")
         require_relative("load_path_cache/core_ext/loaded_features")
       end
 
+      def unload!
+        @enabled = false
+        @loaded_features_index = nil
+        @realpath_cache = nil
+        @load_path_cache = nil
+        ChangeObserver.unregister($LOAD_PATH)
+        ::Kernel.alias_method(:require_relative, :require_relative_without_bootsnap)
+      end
+
       def supported?
         RUBY_ENGINE == "ruby" &&
           RUBY_PLATFORM =~ /darwin|linux|bsd|mswin|mingw|cygwin/

lib/bootsnap/load_path_cache/core_ext/kernel_require.rb

@@ -6,6 +6,8 @@ module Kernel
   alias_method(:require_without_bootsnap, :require)
 
   def require(path)
+    return require_without_bootsnap(path) unless Bootsnap::LoadPathCache.enabled?
+
     string_path = Bootsnap.rb_get_path(path)
     return false if Bootsnap::LoadPathCache.loaded_features_index.key?(string_path)