1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim:set ts=2 sw=2 sts=2 et cindent: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef mozilla_dom_JSActor_h 8 #define mozilla_dom_JSActor_h 9 10 #include "js/TypeDecls.h" 11 #include "ipc/EnumSerializer.h" 12 #include "mozilla/Attributes.h" 13 #include "mozilla/dom/PromiseNativeHandler.h" 14 #include "nsCycleCollectionParticipant.h" 15 #include "nsTHashMap.h" 16 #include "nsWrapperCache.h" 17 18 class nsIGlobalObject; 19 class nsQueryJSActor; 20 21 namespace mozilla { 22 class ErrorResult; 23 24 namespace dom { 25 26 namespace ipc { 27 class StructuredCloneData; 28 } 29 30 class JSActorManager; 31 class JSActorMessageMeta; 32 class QueryPromiseHandler; 33 34 enum class JSActorMessageKind { 35 Message, 36 Query, 37 QueryResolve, 38 QueryReject, 39 EndGuard_, 40 }; 41 42 // Common base class for JSWindowActor{Parent,Child}. 43 class JSActor : public nsISupports, public nsWrapperCache { 44 public: 45 NS_DECL_CYCLE_COLLECTING_ISUPPORTS 46 NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(JSActor) 47 48 explicit JSActor(nsISupports* aGlobal = nullptr); 49 Name()50 const nsCString& Name() const { return mName; } GetName(nsCString & aName)51 void GetName(nsCString& aName) { aName = Name(); } 52 53 void SendAsyncMessage(JSContext* aCx, const nsAString& aMessageName, 54 JS::Handle<JS::Value> aObj, ErrorResult& aRv); 55 56 already_AddRefed<Promise> SendQuery(JSContext* aCx, 57 const nsAString& aMessageName, 58 JS::Handle<JS::Value> aObj, 59 ErrorResult& aRv); 60 GetParentObject()61 nsIGlobalObject* GetParentObject() const { return mGlobal; }; 62 63 protected: 64 // Send the message described by the structured clone data |aData|, and the 65 // message metadata |aMetadata|. The underlying transport should call the 66 // |ReceiveMessage| method on the other side asynchronously. 67 virtual void SendRawMessage(const JSActorMessageMeta& aMetadata, 68 Maybe<ipc::StructuredCloneData>&& aData, 69 Maybe<ipc::StructuredCloneData>&& aStack, 70 ErrorResult& aRv) = 0; 71 72 // Check if a message is so large that IPC will probably crash if we try to 73 // send it. If it is too large, record telemetry about the message. 74 static bool AllowMessage(const JSActorMessageMeta& aMetadata, 75 size_t aDataLength); 76 77 // Helper method to send an in-process raw message. 78 using OtherSideCallback = std::function<already_AddRefed<JSActorManager>()>; 79 static void SendRawMessageInProcess(const JSActorMessageMeta& aMeta, 80 Maybe<ipc::StructuredCloneData>&& aData, 81 Maybe<ipc::StructuredCloneData>&& aStack, 82 OtherSideCallback&& aGetOtherSide); 83 84 virtual ~JSActor() = default; 85 86 void SetName(const nsACString& aName); 87 CanSend()88 bool CanSend() const { return mCanSend; } 89 90 void ThrowStateErrorForGetter(const char* aName, ErrorResult& aRv) const; 91 92 void StartDestroy(); 93 void AfterDestroy(); 94 95 enum class CallbackFunction { DidDestroy, ActorCreated }; 96 void InvokeCallback(CallbackFunction callback); 97 98 virtual void ClearManager() = 0; 99 100 private: 101 friend class JSActorManager; 102 friend class ::nsQueryJSActor; // for QueryInterfaceActor 103 104 nsresult QueryInterfaceActor(const nsIID& aIID, void** aPtr); 105 106 // Called by JSActorManager when they receive raw message data destined for 107 // this actor. 108 void ReceiveMessage(JSContext* aCx, const JSActorMessageMeta& aMetadata, 109 JS::Handle<JS::Value> aData, ErrorResult& aRv); 110 void ReceiveQuery(JSContext* aCx, const JSActorMessageMeta& aMetadata, 111 JS::Handle<JS::Value> aData, ErrorResult& aRv); 112 void ReceiveQueryReply(JSContext* aCx, const JSActorMessageMeta& aMetadata, 113 JS::Handle<JS::Value> aData, ErrorResult& aRv); 114 115 // Call the actual `ReceiveMessage` method, and get the return value. 116 void CallReceiveMessage(JSContext* aCx, const JSActorMessageMeta& aMetadata, 117 JS::Handle<JS::Value> aData, 118 JS::MutableHandle<JS::Value> aRetVal, 119 ErrorResult& aRv); 120 121 // Helper object used while processing query messages to send the final reply 122 // message. 123 class QueryHandler final : public PromiseNativeHandler { 124 public: 125 NS_DECL_CYCLE_COLLECTING_ISUPPORTS 126 NS_DECL_CYCLE_COLLECTION_CLASS(QueryHandler) 127 128 QueryHandler(JSActor* aActor, const JSActorMessageMeta& aMetadata, 129 Promise* aPromise); 130 131 void RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue, 132 ErrorResult& aRv) override; 133 134 void ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue, 135 ErrorResult& aRv) override; 136 137 private: 138 ~QueryHandler() = default; 139 140 void SendReply(JSContext* aCx, JSActorMessageKind aKind, 141 Maybe<ipc::StructuredCloneData>&& aData); 142 143 RefPtr<JSActor> mActor; 144 RefPtr<Promise> mPromise; 145 nsString mMessageName; 146 uint64_t mQueryId; 147 }; 148 149 // A query which hasn't been resolved yet, along with metadata about what 150 // query the promise is for. 151 struct PendingQuery { 152 RefPtr<Promise> mPromise; 153 nsString mMessageName; 154 }; 155 156 nsCOMPtr<nsIGlobalObject> mGlobal; 157 nsCOMPtr<nsISupports> mWrappedJS; 158 nsCString mName; 159 nsTHashMap<nsUint64HashKey, PendingQuery> mPendingQueries; 160 uint64_t mNextQueryId = 0; 161 bool mCanSend = true; 162 }; 163 164 } // namespace dom 165 } // namespace mozilla 166 167 namespace IPC { 168 169 template <> 170 struct ParamTraits<mozilla::dom::JSActorMessageKind> 171 : public ContiguousEnumSerializer< 172 mozilla::dom::JSActorMessageKind, 173 mozilla::dom::JSActorMessageKind::Message, 174 mozilla::dom::JSActorMessageKind::EndGuard_> {}; 175 176 } // namespace IPC 177 178 #endif // !defined(mozilla_dom_JSActor_h) 179