nearbyconnections : Refactor WifiLan.

PiperOrigin-RevId: 399570712

cpp/platform/api/BUILD

@@ -61,6 +61,7 @@ cc_library(
         "webrtc.h",
         "wifi.h",
         "wifi_lan.h",
+        "wifi_lan_v2.h",
     ],
     compatible_with = ["//buildenv/target:non_prod"],
     visibility = [

cpp/platform/api/wifi_lan_v2.h

@@ -0,0 +1,166 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef PLATFORM_API_WIFI_LAN__V2_H_
+#define PLATFORM_API_WIFI_LAN__V2_H_
+
+#include <string>
+
+#include "platform/base/cancellation_flag.h"
+#include "platform/base/input_stream.h"
+#include "platform/base/listeners.h"
+#include "platform/base/nsd_service_info.h"
+#include "platform/base/output_stream.h"
+
+namespace location {
+namespace nearby {
+namespace api {
+
+// Opaque wrapper over a WifiLan service which contains |NsdServiceInfo|.
+class WifiLanServiceV2 {
+ public:
+  virtual ~WifiLanServiceV2() = default;
+
+  // Returns the |NsdServiceInfo| which contains the packed string of
+  // |WifiLanServiceInfo| and the endpoint info with named key in a TXTRecord
+  // map.
+  // The details refer to
+  // https://developer.android.com/reference/android/net/nsd/NsdServiceInfo.html.
+  virtual NsdServiceInfo GetServiceInfo() const = 0;
+};
+
+class WifiLanSocketV2 {
+ public:
+  virtual ~WifiLanSocketV2() = default;
+
+  // Returns the InputStream of the WifiLanSocket.
+  // On error, returned stream will report Exception::kIo on any operation.
+  //
+  // The returned object is not owned by the caller, and can be invalidated once
+  // the WifiLanSocket object is destroyed.
+  virtual InputStream& GetInputStream() = 0;
+
+  // Returns the OutputStream of the WifiLanSocket.
+  // On error, returned stream will report Exception::kIo on any operation.
+  //
+  // The returned object is not owned by the caller, and can be invalidated once
+  // the WifiLanSocket object is destroyed.
+  virtual OutputStream& GetOutputStream() = 0;
+
+  // Returns Exception::kIo on error, Exception::kSuccess otherwise.
+  virtual Exception Close() = 0;
+
+  // Returns valid WifiLanService pointer if there is a connection, and
+  // nullptr otherwise.
+  virtual WifiLanServiceV2* GetRemoteService() = 0;
+};
+
+class WifiLanServerSocket {
+ public:
+  virtual ~WifiLanServerSocket() = default;
+
+  // Returns ip address.
+  virtual std::string GetIpAddress() = 0;
+
+  // Returns port.
+  virtual int GetPort() = 0;
+
+  // Blocks until either:
+  // - at least one incoming connection request is available, or
+  // - ServerSocket is closed.
+  // On success, returns connected socket, ready to exchange data.
+  // Returns nullptr on error.
+  // Once error is reported, it is permanent, and ServerSocket has to be closed.
+  virtual std::unique_ptr<WifiLanSocketV2> Accept() = 0;
+
+  // Returns Exception::kIo on error, Exception::kSuccess otherwise.
+  virtual Exception Close() = 0;
+};
+
+// Container of operations that can be performed over the WifiLan medium.
+class WifiLanMediumV2 {
+ public:
+  virtual ~WifiLanMediumV2() = default;
+
+  // Starts WifiLan advertising.
+  //
+  // nsd_service_info - NsdServiceInfo data that's advertised through mDNS
+  //                    service.
+  // On success if the service is now advertising.
+  // On error if the service cannot start to advertise or the service type in
+  // NsdServiceInfo has been passed previously which StopAdvertising is not
+  // been called.
+  virtual bool StartAdvertising(const NsdServiceInfo& nsd_service_info) = 0;
+
+  // Stops WifiLan advertising.
+  //
+  // nsd_service_info - NsdServiceInfo data that's advertised through mDNS
+  //                    service.
+  // On success if the service stops advertising.
+  // On error if the service cannot stop advertising or the service type in
+  // NsdServiceInfo cannot be found.
+  virtual bool StopAdvertising(const NsdServiceInfo& nsd_service_info) = 0;
+
+  // Callback that is invoked when a discovered service is found or lost.
+  struct DiscoveredServiceCallback {
+    std::function<void(WifiLanServiceV2& service)> service_discovered_cb =
+        DefaultCallback<WifiLanServiceV2&>();
+    std::function<void(WifiLanServiceV2& service)> service_lost_cb =
+        DefaultCallback<WifiLanServiceV2&>();
+  };
+
+  // Starts the discovery of nearby WifiLan services.
+  //
+  // Returns uuid once the WifiLan discovery has been initiated. The uuid
+  // returned is corresponding to callback, if pass the same callback without
+  // StopDiscovery in advance, then there will be two different uuids correspond
+  // to the same callback instance, which might cause unexpected behavior.
+  // Returns uuid if discovery started successfully.
+  // Returns 0 if discovery started unsuccessfully.
+  virtual int StartDiscovery(DiscoveredServiceCallback callback) = 0;
+
+  // Stops the discovery of nearby WifiLan services.
+  //
+  // uuid - The one returned from StartDiscovery.
+  // On success if uuid is matched to the callback and will be removed from the
+  //            list. If list is empty then stops the WifiLan discovery service.
+  // On error if the uuid is not existed, then return immediately.
+  virtual bool StopDiscovery(int uuid) = 0;
+
+  // Connects to a WifiLan service.
+  // On success, returns a new WifiLanSocket.
+  // On error, returns nullptr.
+  virtual std::unique_ptr<WifiLanSocketV2> ConnectToService(
+      WifiLanServiceV2& remote_service,
+      CancellationFlag* cancellation_flag) = 0;
+
+  // Listens for incoming connection.
+  //
+  // port - A port number.
+  //         0 : use a random port.
+  //   1~65536 : open a server socket on that exact port.
+  // On success, returns a new WifiLanServerSocket.
+  // On error, returns nullptr.
+  virtual std::unique_ptr<WifiLanServerSocket> ListenForService(
+      int port = 0) = 0;
+
+  virtual WifiLanServiceV2* GetRemoteService(const std::string& ip_address,
+                                             int port) = 0;
+};
+
+}  // namespace api
+}  // namespace nearby
+}  // namespace location
+
+#endif  // PLATFORM_API_WIFI_LAN__V2_H_