Add performance.memory.jsHeapSizeLimit support (#3928)

This value, in combination with the existing `totalJSHeapSize` and `usedJSHeapSize` values, can help describe memory usage of a webpage. See the MDN reference: https://developer.mozilla.org/en-US/docs/Web/API/Performance/memory#value b/355487905
youtube · Aug 21, 2024 · 5190ee9 · 5190ee9
1 parent 0fa8584
commit 5190ee9
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Showing 5 changed files with 20 additions and 1 deletion.
diff --git a/cobalt/dom/memory_info.cc b/cobalt/dom/memory_info.cc
@@ -61,6 +61,20 @@ uint32 MemoryInfo::used_js_heap_size(
           .used_heap_size);
 }
 
+uint32 MemoryInfo::js_heap_size_limit(
+    script::EnvironmentSettings* environment_settings) const {
+  if (!environment_settings) {
+    return 0u;
+  }
+  return static_cast<uint32>(
+      base::polymorphic_downcast<web::EnvironmentSettings*>(
+          environment_settings)
+          ->context()
+          ->javascript_engine()
+          ->GetHeapStatistics()
+          .heap_size_limit);
+}
+
 uint32 MemoryInfo::media_source_size_limit(
     script::EnvironmentSettings* environment_settings) const {
   auto memory_info = GetDecoderBufferMemoryInfo(environment_settings);

diff --git a/cobalt/dom/memory_info.h b/cobalt/dom/memory_info.h
@@ -33,6 +33,8 @@ class MemoryInfo : public script::Wrappable {
       script::EnvironmentSettings* environment_settings) const;
   uint32 used_js_heap_size(
       script::EnvironmentSettings* environment_settings) const;
+  uint32 js_heap_size_limit(
+      script::EnvironmentSettings* environment_settings) const;
   uint32 media_source_size_limit(
       script::EnvironmentSettings* environment_settings) const;
   uint32 total_media_source_size(

diff --git a/cobalt/dom/memory_info.idl b/cobalt/dom/memory_info.idl
@@ -20,6 +20,7 @@
 ] interface MemoryInfo {
   [CallWith=EnvironmentSettings] readonly attribute unsigned long totalJSHeapSize;
   [CallWith=EnvironmentSettings] readonly attribute unsigned long usedJSHeapSize;
+  [CallWith=EnvironmentSettings] readonly attribute unsigned long jsHeapSizeLimit;
 
   [CallWith=EnvironmentSettings] readonly attribute unsigned long mediaSourceSizeLimit;
   [CallWith=EnvironmentSettings] readonly attribute unsigned long totalMediaSourceSize;

diff --git a/cobalt/script/javascript_engine.h b/cobalt/script/javascript_engine.h
@@ -31,6 +31,7 @@ class GlobalEnvironment;
 struct HeapStatistics {
   size_t total_heap_size;
   size_t used_heap_size;
+  size_t heap_size_limit;
 };
 
 class JavaScriptEngine {

diff --git a/cobalt/script/v8c/v8c_engine.cc b/cobalt/script/v8c/v8c_engine.cc
@@ -206,7 +206,8 @@ HeapStatistics V8cEngine::GetHeapStatistics() {
   v8::HeapStatistics v8_heap_statistics;
   isolate_->GetHeapStatistics(&v8_heap_statistics);
   return {v8_heap_statistics.total_heap_size(),
-          v8_heap_statistics.used_heap_size()};
+          v8_heap_statistics.used_heap_size(),
+          v8_heap_statistics.heap_size_limit()};
 }
 
 void V8cEngine::UpdateDateTimeConfiguration() {