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// Copyright 2019 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 CAST_COMMON_CHANNEL_VIRTUAL_CONNECTION_ROUTER_H_
#define CAST_COMMON_CHANNEL_VIRTUAL_CONNECTION_ROUTER_H_
#include <cstdint>
#include <map>
#include <memory>
#include <string>
#include "absl/types/optional.h"
#include "cast/common/channel/proto/cast_channel.pb.h"
#include "cast/common/channel/virtual_connection.h"
#include "cast/common/public/cast_socket.h"
namespace openscreen {
namespace cast {
class CastMessageHandler;
class ConnectionNamespaceHandler;
// Handles CastSockets by routing received messages to appropriate message
// handlers based on the VirtualConnection's local ID and sending messages over
// the appropriate CastSocket for a VirtualConnection.
//
// Basic model for using this would be:
//
// 1. Foo is a SenderSocketFactory::Client.
//
// 2. Foo calls SenderSocketFactory::Connect, optionally with VCRouter as the
// CastSocket::Client.
//
// 3. Foo gets OnConnected callback and makes whatever local notes it needs
// (e.g. sink "resolved", init app probing state, etc.), then calls
// VCRouter::TakeSocket.
//
// 4. Anything Foo wants to send (launch, app availability, etc.) goes through
// VCRouter::Send via an appropriate VC. The virtual connection is not
// created automatically, so AddConnection() must be called first.
//
// 5. Anything Foo wants to receive must be registered with a handler by calling
// AddHandlerForLocalId().
//
// 6. Foo is expected to clean-up after itself (#4 and #5) by calling
// RemoveConnection() and RemoveHandlerForLocalId().
class VirtualConnectionRouter final : public CastSocket::Client {
public:
class SocketErrorHandler {
public:
virtual void OnClose(CastSocket* socket) = 0;
virtual void OnError(CastSocket* socket, Error error) = 0;
};
VirtualConnectionRouter();
~VirtualConnectionRouter() override;
// Adds a VirtualConnection, if one does not already exist, to enable routing
// of peer-to-peer messages.
void AddConnection(VirtualConnection virtual_connection,
VirtualConnection::AssociatedData associated_data);
// Removes a VirtualConnection and returns true if a connection matching
// |virtual_connection| was found and removed.
bool RemoveConnection(const VirtualConnection& virtual_connection,
VirtualConnection::CloseReason reason);
// Removes all VirtualConnections whose local endpoint matches the given
// |local_id|.
void RemoveConnectionsByLocalId(const std::string& local_id);
// Removes all VirtualConnections whose traffic passes over the socket
// referenced by |socket_id|.
void RemoveConnectionsBySocketId(int socket_id);
// Returns the AssociatedData for a |virtual_connection| if a connection
// exists, nullopt otherwise. The pointer isn't stable in the long term; so,
// if it actually needs to be stored for later, the caller should make a copy.
absl::optional<const VirtualConnection::AssociatedData*> GetConnectionData(
const VirtualConnection& virtual_connection) const;
// Adds/Removes a CastMessageHandler for all messages destined for the given
// |endpoint| referred to by |local_id|, and returns whether the given
// |local_id| was successfully added/removed.
//
// Note: Clients will need to separately call AddConnection(), and
// RemoveConnection() or RemoveConnectionsByLocalId().
bool AddHandlerForLocalId(std::string local_id, CastMessageHandler* endpoint);
bool RemoveHandlerForLocalId(const std::string& local_id);
// |error_handler| must live until either its OnError or OnClose is called.
void TakeSocket(SocketErrorHandler* error_handler,
std::unique_ptr<CastSocket> socket);
void CloseSocket(int id);
Error Send(VirtualConnection virtual_conn,
::cast::channel::CastMessage message);
Error BroadcastFromLocalPeer(std::string local_id,
::cast::channel::CastMessage message);
// CastSocket::Client overrides.
void OnError(CastSocket* socket, Error error) override;
void OnMessage(CastSocket* socket,
::cast::channel::CastMessage message) override;
protected:
friend class ConnectionNamespaceHandler;
void set_connection_namespace_handler(ConnectionNamespaceHandler* handler) {
connection_handler_ = handler;
}
private:
// This struct simply stores the remainder of the data {VirtualConnection,
// VirtualConnection::AssociatedData} that is not broken up into map keys for
// |connections_|.
struct VCTail {
std::string peer_id;
VirtualConnection::AssociatedData data;
};
struct SocketWithHandler {
std::unique_ptr<CastSocket> socket;
SocketErrorHandler* error_handler;
};
ConnectionNamespaceHandler* connection_handler_ = nullptr;
std::map<int /* socket_id */,
std::multimap<std::string /* local_id */, VCTail>>
connections_;
std::map<int, SocketWithHandler> sockets_;
std::map<std::string /* local_id */, CastMessageHandler*> endpoints_;
};
} // namespace cast
} // namespace openscreen
#endif // CAST_COMMON_CHANNEL_VIRTUAL_CONNECTION_ROUTER_H_