gecko-dev/dom/ipc/JSActor.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_dom_JSActor_h
#define mozilla_dom_JSActor_h
#include "js/TypeDecls.h"
#include "ipc/IPCMessageUtils.h"
#include "mozilla/Attributes.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/dom/PromiseNativeHandler.h"
#include "nsCycleCollectionParticipant.h"
#include "nsRefPtrHashtable.h"
#include "nsWrapperCache.h"
class nsIGlobalObject;
class nsQueryActorChild;
class nsQueryActorParent;
namespace mozilla {
namespace dom {
enum class JSActorMessageKind {
Message,
Query,
QueryResolve,
QueryReject,
EndGuard_,
};
class JSActorMessageMeta;
class QueryPromiseHandler;
// Common base class for JSWindowActor{Parent,Child}.
class JSActor : public nsISupports, public nsWrapperCache {
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(JSActor)
JSActor();
enum class Type { Parent, Child };
enum class CallbackFunction { WillDestroy, DidDestroy, ActorCreated };
const nsCString& Name() const { return mName; }
void SendAsyncMessage(JSContext* aCx, const nsAString& aMessageName,
JS::Handle<JS::Value> aObj, ErrorResult& aRv);
already_AddRefed<Promise> SendQuery(JSContext* aCx,
const nsAString& aMessageName,
JS::Handle<JS::Value> aObj,
ErrorResult& aRv);
void ReceiveRawMessage(const JSActorMessageMeta& aMetadata,
ipc::StructuredCloneData&& aData,
ipc::StructuredCloneData&& aStack);
virtual nsIGlobalObject* GetParentObject() const = 0;
void RejectPendingQueries();
protected:
// Send the message described by the structured clone data |aData|, and the
// message metadata |aMetadata|. The underlying transport should call the
// |ReceiveMessage| method on the other side asynchronously.
virtual void SendRawMessage(const JSActorMessageMeta& aMetadata,
ipc::StructuredCloneData&& aData,
ipc::StructuredCloneData&& aStack,
ErrorResult& aRv) = 0;
// Check if a message is so large that IPC will probably crash if we try to
// send it. If it is too large, record telemetry about the message.
static bool AllowMessage(const JSActorMessageMeta& aMetadata,
size_t aDataLength);
virtual ~JSActor() = default;
void SetName(const nsACString& aName);
void StartDestroy();
void AfterDestroy();
void InvokeCallback(CallbackFunction willDestroy);
private:
friend class ::nsQueryActorChild; // for QueryInterfaceActor
friend class ::nsQueryActorParent; // for QueryInterfaceActor
nsresult QueryInterfaceActor(const nsIID& aIID, void** aPtr);
void ReceiveMessageOrQuery(JSContext* aCx,
const JSActorMessageMeta& aMetadata,
JS::Handle<JS::Value> aData, ErrorResult& aRv);
void ReceiveQueryReply(JSContext* aCx, const JSActorMessageMeta& aMetadata,
JS::Handle<JS::Value> aData, ErrorResult& aRv);
// Helper object used while processing query messages to send the final reply
// message.
class QueryHandler final : public PromiseNativeHandler {
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS(QueryHandler)
QueryHandler(JSActor* aActor, const JSActorMessageMeta& aMetadata,
Promise* aPromise);
void RejectedCallback(JSContext* aCx,
JS::Handle<JS::Value> aValue) override;
void ResolvedCallback(JSContext* aCx,
JS::Handle<JS::Value> aValue) override;
private:
~QueryHandler() = default;
void SendReply(JSContext* aCx, JSActorMessageKind aKind,
ipc::StructuredCloneData&& aData);
RefPtr<JSActor> mActor;
RefPtr<Promise> mPromise;
nsString mMessageName;
uint64_t mQueryId;
};
nsCOMPtr<nsISupports> mWrappedJS;
nsCString mName;
nsRefPtrHashtable<nsUint64HashKey, Promise> mPendingQueries;
uint64_t mNextQueryId;
};
} // namespace dom
} // namespace mozilla
namespace IPC {
template <>
struct ParamTraits<mozilla::dom::JSActorMessageKind>
: public ContiguousEnumSerializer<
mozilla::dom::JSActorMessageKind,
mozilla::dom::JSActorMessageKind::Message,
mozilla::dom::JSActorMessageKind::EndGuard_> {};
} // namespace IPC
#endif // !defined(mozilla_dom_JSActor_h)