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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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_ipc_IPCStreamSource_h
#define mozilla_ipc_IPCStreamSource_h
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/dom/WorkerRef.h"
class nsIAsyncInputStream;
namespace mozilla {
namespace wr {
struct ByteBuffer;
} // namespace wr
namespace ipc {
class ParentToChildStreamActorManager;
class ChildToParentStreamActorManager;
class PChildToParentStreamChild;
class PParentToChildStreamParent;
// The IPCStream IPC actor is designed to push an nsIInputStream from child to
// parent or parent to child incrementally. This is mainly needed for streams
// such as nsPipe that may not yet have all their data available when the
// stream must be sent across an IPC boundary. While many streams are handled
// by SerializeInputStream(), these streams cannot be serialized and must be
// sent using this actor.
//
// The IPCStream actor only support async, non-blocking streams because they
// must be read inline on the main thread and Worker threads.
//
// In general, the creation and handling of the IPCStream actor cannot be
// abstracted away behind SerializeInputStream() because the actor must be
// carefully managed. Specifically:
//
// 1) The data flow must be explicitly initiated by calling
// IPCStreamSource{Child,Parent}::Start() after the actor has been sent to
// the other-side actor.
// 2) If the actor is never sent to the other-side, then this code must
// call IPCStreamSource{Child,Parent}::StartDestroy() to avoid memory leaks.
// 3) The IPCStreamSource actor can only be used on threads that can be
// guaranteed to stay alive as long as the actor is alive. Right now
// this limits IPCStream to the main thread and Worker threads.
//
// In general you should probably use the AutoIPCStreamSource RAII class
// defined in InputStreamUtils.h instead of using IPCStreamSource directly.
class IPCStreamSource {
public:
// Create a IPCStreamSource using a ChildToParentStreamActorManager manager.
// This can return nullptr if the provided stream is blocking.
static PChildToParentStreamChild* Create(
nsIAsyncInputStream* aInputStream,
ChildToParentStreamActorManager* aManager);
// Create a IPCStreamSource using a ParentToChildStreamActorManager manager.
// This can return nullptr if the provided stream is blocking.
static PParentToChildStreamParent* Create(
nsIAsyncInputStream* aInputStream,
ParentToChildStreamActorManager* aManager);
static IPCStreamSource* Cast(PChildToParentStreamChild* aActor);
static IPCStreamSource* Cast(PParentToChildStreamParent* aActor);
// Start reading data from the nsIAsyncInputStream used to create the actor.
// This must be called after the actor is passed to the parent. If you
// use AutoIPCStream this is handled automatically.
void Start();
// Start cleaning up the actor. This must be called if the actor is never
// sent to the other side. If you use AutoIPCStream this is handled
// automatically.
void StartDestroy();
protected:
IPCStreamSource(nsIAsyncInputStream* aInputStream);
virtual ~IPCStreamSource();
bool Initialize();
void ActorDestroyed();
void OnEnd(nsresult aRv);
virtual void Close(nsresult aRv) = 0;
virtual void SendData(const wr::ByteBuffer& aBuffer) = 0;
void ActorConstructed();
private:
class Callback;
void DoRead();
void Wait();
void OnStreamReady(Callback* aCallback);
nsCOMPtr<nsIAsyncInputStream> mStream;
RefPtr<Callback> mCallback;
RefPtr<dom::StrongWorkerRef> mWorkerRef;
#ifdef DEBUG
protected:
#endif
enum { ePending, eActorConstructed, eClosed } mState;
private:
NS_DECL_OWNINGTHREAD
};
} // namespace ipc
} // namespace mozilla
#endif // mozilla_ipc_IPCStreamSource_h
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