fixup! lib: allow CJS source map cache to be reclaimed

Author: legendecas

lib/internal/source_map/source_map_cache_map.js

@@ -5,18 +5,22 @@ const {
   ObjectFreeze,
   SafeFinalizationRegistry,
   SafeMap,
-  SafeWeakMap,
   SafeWeakRef,
   SymbolIterator,
 } = primordials;
+const {
+  privateSymbols: {
+    source_map_data_private_symbol,
+  },
+} = internalBinding('util');
 
 /**
  * Specialized WeakMap that caches source map entries by `filename` and `sourceURL`.
  * Cached entries can be iterated with `for..of`.
  *
  * The cache map maintains the cache entries by:
  * - `weakTargetMap`(Map): a strong sourceURL -> WeakRef(Module),
- * - `weakMap`(WeakMap): a Module instance object -> source map data.
+ * - WeakRef(Module[source_map_data_private_symbol]): source map data.
  *
  * Obsolete `weakTargetMap` entries are removed by the `finalizationRegistry` callback.
  * This pattern decouples the strong url reference to the source map data and allow the
@@ -33,7 +37,6 @@ class SourceMapCacheMap {
    * the cache by the `finalizationRegistry`.
    */
   #weakTargetMap = new SafeMap();
-  #weakMap = new SafeWeakMap();
 
   #cleanup = ({ keys }) => {
     // Delete the entry if the weak target has been reclaimed.
@@ -58,7 +61,7 @@ class SourceMapCacheMap {
   set(keys, value, weakTarget) {
     const weakRef = new SafeWeakRef(weakTarget);
     ArrayPrototypeForEach(keys, (key) => this.#weakTargetMap.set(key, weakRef));
-    this.#weakMap.set(weakTarget, value);
+    weakTarget[source_map_data_private_symbol] = value;
     this.#finalizationRegistry.register(weakTarget, { keys });
   }
 
@@ -72,7 +75,7 @@ class SourceMapCacheMap {
     if (target === undefined) {
       return;
     }
-    return this.#weakMap.get(target);
+    return target[source_map_data_private_symbol];
   }
 
   /**
@@ -92,7 +95,7 @@ class SourceMapCacheMap {
       const { 0: key, 1: weakRef } = result.value;
       const target = weakRef.deref();
       if (target == null) return next();
-      const value = this.#weakMap.get(target);
+      const value = target[source_map_data_private_symbol];
       return { done: false, value: [key, value] };
     };
 

src/env_properties.h

@@ -29,7 +29,8 @@
   V(untransferable_object_private_symbol, "node:untransferableObject")         \
   V(exit_info_private_symbol, "node:exit_info_private_symbol")                 \
   V(promise_trace_id, "node:promise_trace_id")                                 \
-  V(require_private_symbol, "node:require_private_symbol")
+  V(require_private_symbol, "node:require_private_symbol")                     \
+  V(source_map_data_private_symbol, "node:source_map_data_private_symbol")
 
 // Symbols are per-isolate primitives but Environment proxies them
 // for the sake of convenience.

src/module_wrap.cc

@@ -248,6 +248,14 @@ void ModuleWrap::New(const FunctionCallbackInfo<Value>& args) {
     return;
   }
 
+  // Initialize an empty slot for source map cache before the object is frozen.
+  if (that->SetPrivate(context,
+                       realm->isolate_data()->source_map_data_private_symbol(),
+                       Undefined(isolate))
+          .IsNothing()) {
+    return;
+  }
+
   // Use the extras object as an object whose GetCreationContext() will be the
   // original `context`, since the `Context` itself strictly speaking cannot
   // be stored in an internal field.