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I am developing wifi direct based file transfer application. I can see that the transfer speed using TCP socket is not satisfactory. The speed is normally 1Mbps. Whenever I analyze the data transfer graph, I can see a lot of spikes and many seconds are with no data transfer at all. I know the transfer speed should be much higher (may be 20-30Mbps) Please help me in increasing the transfer speed. The serversocket that accepts the connection is

private void serverTask() {
        Log.v(TAG, "server task");
        try {
            serverRunning = true;
            ServerSocket serverSocket = new ServerSocket(
                    DeviceDetailFragment.PORT);
            serverSocket.setReceiveBufferSize(TCP_BUFFER_SIZE);


            Socket client = serverSocket.accept();

            BufferedInputStream inputstream = new BufferedInputStream(
                    client.getInputStream());
            // new BufferedInputStream(client.getInputStream(), 8 * 1024);
            BufferedReader bufferedStream = new BufferedReader(
                    new InputStreamReader(inputstream));


                fileName = bufferedStream.readLine();
                fileSizeInBytes = bufferedStream.readLine();
                fileMime = bufferedStream.readLine();

                f = new File(Globals.fileSavingLocation + fileName);

                File dirs = new File(f.getParent());
                if (!dirs.exists())
                    dirs.mkdirs();

                if (f.exists()) {
                    f.delete();
                }

                f.createNewFile();

        IOUtils.copy(inputstream, new FileOutputStream(f));


                serverSocket.close();
            }
            isSuccessful = true;

        } catch (IOException e) {
            isSuccessful = false;
            Log.e(TAG, e.getMessage());

        }
        serverRunning = false;

    }

And the client that sends the data has following code:

 private void clientTask(Intent intent) {
            String fileUri = intent.getExtras().getString(EXTRAS_FILE_PATH);
            String host = intent.getExtras().getString(EXTRAS_ADDRESS);
            String fileName = intent.getExtras().getString(FILE_NAME);
            String fileMimeType = intent.getExtras().getString(FILE_MIME_TYPE);
            final long sizeInBytes = intent.getExtras().getLong(FILE_SIZE);
            Socket socket = new Socket();
            int port = intent.getExtras().getInt(EXTRAS_PORT);

            try {
                socket.setSendBufferSize(TCP_BUFFER_SIZE);
                socket.bind(null);
                socket.connect((new InetSocketAddress(host, port)),
                        SOCKET_TIMEOUT);

                BufferedOutputStream stream = new BufferedOutputStream(
                        socket.getOutputStream());
                ContentResolver cr = FileTransferService.this
                        .getApplicationContext().getContentResolver();
                InputStream is = null;

                BufferedWriter bufferStream = new BufferedWriter(
                        new OutputStreamWriter(stream));


                bufferStream.write(fileName);
                bufferStream.newLine();
                bufferStream.flush();
                bufferStream.write(String.valueOf(sizeInBytes));
                bufferStream.newLine();
                bufferStream.flush();

                bufferStream.write(fileMimeType);
                bufferStream.newLine();
                bufferStream.flush();


                try {

                    is = new BufferedInputStream(cr.openInputStream(Uri
                            .parse(fileUri)));

                } catch (FileNotFoundException e) {

                    isSuccessful = false;

                }
 IOUtils.copy(is, stream);


                isSuccessful = true;

            } catch (IOException e) {
                Log.e(TAG, e.getMessage());
                isSuccessful = false;
            } finally {
                if (socket != null) {
                    if (socket.isConnected()) {
                        try {
                            socket.close();
                        } catch (IOException e) {
                            // Give up
                            e.printStackTrace();
                        }
                    }
                }
            }

The value of TCP_BUFFER_SIZE is set to 1024*512.

I have tried a lot altering the value of TCP_BUFFER_SIZE but with no luck. I replaced my implementation of copying stream by Apache Commons IOUtils. Help me out

Update: Please see the following transfer graph Graph of transfer speed

4

2 回答 2

2

看来您正在重载缓冲区，来自setReceiveBufferSize() javadoc

随后可以通过调用 Socket.setReceiveBufferSize(int) 更改该值。但是，如果应用程序希望允许大于 64K 字节的接收窗口（如 RFC1323 所定义），则必须在 ServerSocket 中设置建议的值，然后才能将其绑定到本地地址。这意味着，必须使用无参数构造函数创建 ServerSocket，然后必须调用 setReceiveBufferSize()，最后通过调用 bind() 将 ServerSocket 绑定到地址。

于 2013-04-17T11:58:48.663 回答
0

我会尝试使用普通套接字而不使用文件进行简单的数据传输。

有一个简单的服务器，它在连接时发送 100 MB 的空数据。让客户端尽可能快地读取该数据，并报告它获得的吞吐量。在同一台机器上，您应该很容易看到超过 100 MB/s 的速度。一旦这给出了一个好的数字，请在 android 客户端上尝试。

于 2013-04-17T11:53:10.570 回答