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// Copyright 2022 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef IPCZ_SRC_IPCZ_ROUTER_LINK_H_
#define IPCZ_SRC_IPCZ_ROUTER_LINK_H_
#include "ipcz/link_type.h"
#include "ipcz/sequence_number.h"
#include "util/ref_counted.h"
namespace ipcz {
class Parcel;
class Router;
// A RouterLink represents one endpoint of a link between two Routers. All
// subclasses must be thread-safe.
//
// NOTE: Implementations of this class must take caution when calling into
// Routers, since such calls may re-enter the RouterLink implementation to
// deactivate it. As a general rule, calls into Router should be made using a
// Router reference owned on the calling stack rather than a reference owned by
// the RouterLink.
class RouterLink : public RefCounted {
public:
using Pair = std::pair<Ref<RouterLink>, Ref<RouterLink>>;
// Indicates what type of link this is. See LinkType documentation.
virtual LinkType GetType() const = 0;
// Returns true iff this is a LocalRouterLink whose peer router is `router`.
virtual bool HasLocalPeer(const Router& router) = 0;
// Passes a parcel to the Router on the other side of this link to be queued
// and/or router further.
virtual void AcceptParcel(Parcel& parcel) = 0;
// Notifies the Router on the other side of the link that the route has been
// closed from this side. `sequence_length` is the total number of parcels
// transmitted from the closed side before it was closed.
virtual void AcceptRouteClosure(SequenceNumber sequence_length) = 0;
// Deactivates this RouterLink to sever any binding it may have to a specific
// Router. Note that deactivation is not necessarily synchronous, so some
// in-progress calls into a Router may still complete on behalf of this
// RouterLink after Deactivate() returns. This call only ensures that the link
// will stop calling into (and generally stop referencing) the Router ASAP.
virtual void Deactivate() = 0;
// Generates a string description of this RouterLink for debug logging.
virtual std::string Describe() const = 0;
protected:
~RouterLink() override = default;
};
} // namespace ipcz
#endif // IPCZ_SRC_IPCZ_ROUTER_LINK_H_