Bug 1898677 - Cache the result of bytecode encoding condition. r=nbp

Differential Revision: https://phabricator.services.mozilla.com/D211517

js/loader/ScriptLoadRequest.h

@@ -182,9 +182,33 @@ class ScriptLoadRequest : public nsISupports,
 
   void SetPendingFetchingError();
 
-  void MarkForBytecodeEncoding(JSScript* aScript);
+  bool PassedConditionForBytecodeEncoding() const {
+    return mBytecodeEncodingPlan == BytecodeEncodingPlan::PassedCondition ||
+           mBytecodeEncodingPlan == BytecodeEncodingPlan::MarkedForEncode;
+  }
 
-  bool IsMarkedForBytecodeEncoding() const;
+  void MarkSkippedBytecodeEncoding() {
+    MOZ_ASSERT(mBytecodeEncodingPlan == BytecodeEncodingPlan::Uninitialized);
+    mBytecodeEncodingPlan = BytecodeEncodingPlan::Skipped;
+  }
+
+  void MarkPassedConditionForBytecodeEncoding() {
+    MOZ_ASSERT(mBytecodeEncodingPlan == BytecodeEncodingPlan::Uninitialized);
+    mBytecodeEncodingPlan = BytecodeEncodingPlan::PassedCondition;
+  }
+
+  bool IsMarkedForBytecodeEncoding() const {
+    return mBytecodeEncodingPlan == BytecodeEncodingPlan::MarkedForEncode;
+  }
+
+ protected:
+  void MarkForBytecodeEncoding() {
+    MOZ_ASSERT(mBytecodeEncodingPlan == BytecodeEncodingPlan::PassedCondition);
+    mBytecodeEncodingPlan = BytecodeEncodingPlan::MarkedForEncode;
+  }
+
+ public:
+  void MarkScriptForBytecodeEncoding(JSScript* aScript);
 
   mozilla::CORSMode CORSMode() const { return mFetchOptions->mCORSMode; }
 
@@ -218,6 +242,23 @@ class ScriptLoadRequest : public nsISupports,
   State mState;           // Are we still waiting for a load to complete?
   bool mFetchSourceOnly;  // Request source, not cached bytecode.
 
+  enum class BytecodeEncodingPlan : uint8_t {
+    // This is not yet considered for encoding.
+    Uninitialized,
+
+    // This is marked for skipping the encoding.
+    Skipped,
+
+    // This fits the condition for the encoding (e.g. file size, fetch count).
+    PassedCondition,
+
+    // This is marked for encoding, with setting sufficient input,
+    // e.g. mScriptForBytecodeEncoding for script.
+    MarkedForEncode,
+  };
+  BytecodeEncodingPlan mBytecodeEncodingPlan =
+      BytecodeEncodingPlan::Uninitialized;
+
   // The referrer policy used for the initial fetch and for fetching any
   // imported modules
   enum mozilla::dom::ReferrerPolicy mReferrerPolicy;
@@ -247,10 +288,9 @@ class ScriptLoadRequest : public nsISupports,
   RefPtr<LoadedScript> mLoadedScript;
 
   // Holds the top-level JSScript that corresponds to the current source, once
-  // it is parsed, and planned to be saved in the bytecode cache.
+  // it is parsed, and marked to be saved in the bytecode cache.
   //
   // NOTE: This field is not used for ModuleLoadRequest.
-  //       See ModuleLoadRequest::mIsMarkedForBytecodeEncoding.
   JS::Heap<JSScript*> mScriptForBytecodeEncoding;
 
   // Holds the Cache information, which is used to register the bytecode