microsoft-visualbasic-runtime/Net/Tcp/Persistent/Socket/TcpClient.vb

#Region "Microsoft.VisualBasic::0d5887b9e22b6c438eae8da8f0f4884f, Microsoft.VisualBasic.Core\Net\Tcp\Persistent\Socket\TcpClient.vb"

    ' Author:
    ' 
    '       asuka (amethyst.asuka@gcmodeller.org)
    '       xie (genetics@smrucc.org)
    '       xieguigang (xie.guigang@live.com)
    ' 
    ' Copyright (c) 2018 GPL3 Licensed
    ' 
    ' 
    ' GNU GENERAL PUBLIC LICENSE (GPL3)
    ' 
    ' 
    ' This program is free software: you can redistribute it and/or modify
    ' it under the terms of the GNU General Public License as published by
    ' the Free Software Foundation, either version 3 of the License, or
    ' (at your option) any later version.
    ' 
    ' This program is distributed in the hope that it will be useful,
    ' but WITHOUT ANY WARRANTY; without even the implied warranty of
    ' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ' GNU General Public License for more details.
    ' 
    ' You should have received a copy of the GNU General Public License
    ' along with this program. If not, see <http://www.gnu.org/licenses/>.



    ' /********************************************************************************/

    ' Summaries:

    '     Class PersistentClient
    ' 
    '         Properties: MessageHandler, MyLocalPort, MyServerHashCode, RemoteServerShutdown
    ' 
    '         Constructor: (+3 Overloads) Sub New
    ' 
    '         Function: readDataBuffer, Run, ToString
    ' 
    '         Sub: __receive, __send, BeginConnect, ConnectCallback, (+2 Overloads) Dispose
    '              Receive, ReceiveCallback, requestHandle, WaitForConnected, WaitForHash
    '              waitReceive
    '         Class StateObject
    ' 
    ' 
    ' 
    ' 
    ' 
    ' 
    ' /********************************************************************************/

#End Region

Imports System.Net.Sockets
Imports System.Reflection
Imports System.Text
Imports System.Threading
Imports Microsoft.VisualBasic.ApplicationServices.Debugging.ExceptionExtensions
Imports Microsoft.VisualBasic.Language.Default
Imports Microsoft.VisualBasic.Linq
Imports Microsoft.VisualBasic.Net.Protocols
Imports Microsoft.VisualBasic.Net.Tcp.Persistent.Application.Protocols
Imports Microsoft.VisualBasic.Parallel
Imports TcpEndPoint = System.Net.IPEndPoint
Imports TcpSocket = System.Net.Sockets.Socket

Namespace Net.Tcp.Persistent.Socket

    ''' <summary>
    ''' 请注意，这个对象是应用于客户端与服务器保持长连接所使用，并不会主动发送消息给服务器，而是被动的接受服务器的数据请求
    ''' </summary>
    ''' <remarks></remarks>
    Public Class PersistentClient : Implements IDisposable

        Protected _EndReceive As Boolean
        Protected connectDone As ManualResetEvent

#Region "IDisposable Support"
        Protected disposedValue As Boolean ' To detect redundant calls

#Region "Internal Fields"

        ''' <summary>
        ''' The port number for the remote device.
        ''' </summary>
        ''' <remarks></remarks>
        Protected port As Integer

        ''' <summary>
        ''' Remote End Point
        ''' </summary>
        ''' <remarks></remarks>
        Protected ReadOnly remoteEP As TcpEndPoint
        Protected remoteHost As String

        Const LocalIPAddress As String = "127.0.0.1"

        Dim _ExceptionHandler As ExceptionHandler

        Shared ReadOnly defaultHandler As New [Default](Of ExceptionHandler)(AddressOf VBDebugger.PrintException)

        Sub New(remoteDevice As TcpEndPoint, Optional ExceptionHandler As ExceptionHandler = Nothing)
            Call Me.New(remoteDevice.Address.ToString, remoteDevice.Port, ExceptionHandler)
        End Sub

        ''' <summary>
        '''
        ''' </summary>
        ''' <param name="client">Copy the TCP client connection profile data from this object.(从本客户端对象之中复制出连接配置参数以进行初始化操作)</param>
        ''' <param name="ExceptionHandler"></param>
        ''' <remarks></remarks>
        Sub New(client As PersistentClient, Optional ExceptionHandler As ExceptionHandler = Nothing)
            remoteHost = client.remoteHost
            port = client.port
            _ExceptionHandler = ExceptionHandler Or defaultHandler
            remoteEP = New TcpEndPoint(System.Net.IPAddress.Parse(remoteHost), port)
        End Sub

        ''' <summary>
        '''
        ''' </summary>
        ''' <param name="RemotePort"></param>
        ''' <param name="ExceptionHandler">Public Delegate Sub ExceptionHandler(ex As Exception)</param>
        ''' <remarks></remarks>
        Sub New(HostName$, RemotePort As Integer, Optional ExceptionHandler As ExceptionHandler = Nothing)
            remoteHost = HostName

            If String.Equals(remoteHost, "localhost", StringComparison.OrdinalIgnoreCase) Then
                remoteHost = LocalIPAddress
            End If

            port = RemotePort
            _ExceptionHandler = ExceptionHandler Or defaultHandler
            remoteEP = New TcpEndPoint(System.Net.IPAddress.Parse(remoteHost), port)
        End Sub

        Public ReadOnly Property MyLocalPort As Integer

        ''' <summary>
        ''' 本客户端socket在服务器上面的哈希句柄值
        ''' </summary>
        ''' <returns></returns>
        Public ReadOnly Property MyServerHashCode As Integer = 0

        ''' <summary>
        ''' 远程主机强制关闭连接之后触发这个动作
        ''' </summary>
        ''' <returns></returns>
        Public Property RemoteServerShutdown As MethodInvoker
        ''' <summary>
        ''' 将从服务器来的推送消息的处理过程赋值在这个属性之中
        ''' </summary>
        ''' <returns></returns>
        Public Property MessageHandler As ProcessMessagePush

        Public Sub BeginConnect()
            Call Parallel.RunTask(AddressOf Run)
        End Sub

        ''' <summary>
        ''' 函数会像服务器上面的socket对象一样在这里发生阻塞
        ''' </summary>
        ''' <remarks></remarks>
        Public Function Run() As Integer
            ' ManualResetEvent instances signal completion.
            connectDone = New ManualResetEvent(False)

            ' Establish the remote endpoint for the socket.
            ' For this example use local machine.
            ' Create a TCP/IP socket.
            Dim client As New TcpSocket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
            Call client.Bind(New TcpEndPoint(System.Net.IPAddress.Any, 0))
            ' Connect to the remote endpoint.
            Call client.BeginConnect(remoteEP, New AsyncCallback(AddressOf ConnectCallback), client)
            ' Wait for connect.
            Call connectDone.WaitOne()
            Call Console.WriteLine(client.LocalEndPoint.ToString)

            _MyLocalPort = DirectCast(client.LocalEndPoint, TcpEndPoint).Port
            _EndReceive = True

            Dim state As New StateObject With {
                .workSocket = client
            }

            Do While Not Me.disposedValue
                Call Thread.Sleep(1)

                If _EndReceive Then
                    _EndReceive = False
                    state.Stack = 0
                    Call Receive(state)
                End If
            Loop

            Return 0
        End Function

        ' This code added by Visual Basic to correctly implement the disposable pattern.
        Public Sub Dispose() Implements IDisposable.Dispose
            ' Do not change this code.  Put cleanup code in Dispose(disposing As Boolean) above.
            Dispose(True)
            GC.SuppressFinalize(Me)
        End Sub
#End Region

        Public Overrides Function ToString() As String
            Return $"Remote_connection={remoteHost}:{port}"
        End Function

        Public Sub WaitForConnected()
            Do While Me._MyLocalPort = 0
                Call Thread.Sleep(1)
            Loop
        End Sub

        Public Sub WaitForHash()
            Do While MyServerHashCode = 0
                Call Thread.Sleep(1)
            Loop
        End Sub

        ''' <summary>
        ''' Retrieve the socket from the state object.
        ''' </summary>
        ''' <param name="ar"></param>
        Protected Sub ConnectCallback(ar As IAsyncResult)
            Dim client As TcpSocket = CType(ar.AsyncState, TcpSocket)

            ' Complete the connection.
            Try
                client.EndConnect(ar)
                ' Signal that the connection has been made.
                Call connectDone.Set()
            Catch ex As Exception
                Call _ExceptionHandler(ex)
            End Try
        End Sub 'ConnectCallback

        ' IDisposable
        Protected Overridable Sub Dispose(disposing As Boolean)
            If Not Me.disposedValue Then
                If disposing Then
                    ' TODO: dispose managed state (managed objects).
                    Call connectDone.Set()  ' ManualResetEvent instances signal completion.
                    '    Call receiveDone.Set() '中断服务器的连接
                End If

                ' TODO: free unmanaged resources (unmanaged objects) and override Finalize() below.
                ' TODO: set large fields to null.
            End If
            Me.disposedValue = True
        End Sub

        ''' <summary>
        ''' An exception of type '<see cref="SocketException"/>' occurred in System.dll but was not handled in user code
        ''' Additional information: A request to send or receive data was disallowed because the socket is not connected and
        ''' (when sending on a datagram socket using a sendto call) no address was supplied
        ''' </summary>
        ''' <param name="client"></param>
        Protected Sub Receive(client As StateObject)
            ' Begin receiving the data from the remote device.
            Try
                _EndReceive = False
                Call __receive(client)
            Catch ex As Exception ' 现有的连接被强制关闭
                Call Me._ExceptionHandler(ex)

                If Not Me.RemoteServerShutdown Is Nothing Then
                    Call RemoteServerShutdown()()
                End If

                Try
                    Call client.workSocket.Shutdown(SocketShutdown.Both)
                Catch exc As Exception
                    Call App.LogException(exc, MethodBase.GetCurrentMethod.GetFullName)
                End Try
            End Try
        End Sub 'Receive

        Private Sub __receive(client As StateObject)
            Dim ReceiveHandle = New AsyncCallback(AddressOf ReceiveCallback)

            Call client.workSocket.BeginReceive(client.readBuffer, 0, StateObject.BufferSize, 0, ReceiveHandle, client)
            Call waitReceive()

            client.Stack += 1

            If client.Stack > 1000 Then
                _EndReceive = True
                Return
            Else
                Call Thread.Sleep(1)
            End If

            If Not Me.disposedValue Then
                '还没有结束
                Call Receive(client)
            End If
        End Sub

        ''' <summary>
        ''' ????
        ''' An exception of type 'System.Net.Sockets.SocketException' occurred in System.dll but was not handled in user code
        ''' Additional information: A request to send or receive data was disallowed because the socket is not connected and
        ''' (when sending on a datagram socket using a sendto call) no address was supplied
        ''' </summary>
        ''' <param name="client"></param>
        ''' <param name="data"></param>
        ''' <remarks></remarks>
        Private Sub __send(client As TcpSocket, data As String)
            ' Convert the string data to byte data using ASCII encoding.
            Dim byteData As Byte() = Encoding.ASCII.GetBytes(data)
            ' Begin sending the data to the remote device.
            Try
                Call client.Send(byteData, byteData.Length, SocketFlags.None)
            Catch ex As Exception
                Call Me._ExceptionHandler(ex)
                Call App.LogException(ex, MethodBase.GetCurrentMethod.GetFullName)
            End Try
        End Sub 'Send

        ''' <summary>
        ''' Read data from the remote device.
        ''' </summary>
        ''' <param name="state"></param>
        ''' <param name="ar"></param>
        ''' <returns></returns>
        Private Function readDataBuffer(state As StateObject, ar As IAsyncResult) As Byte()
            Dim client As TcpSocket = state.workSocket
            Dim bytesRead As Integer

            Try
                bytesRead = client.EndReceive(ar)
            Catch ex As Exception
                Call _ExceptionHandler(ex)
                Call _EndReceive.SetValue(True)
                Return Nothing
            Finally
                _EndReceive = True
            End Try

            Dim bytesBuffer = state.readBuffer.Takes(bytesRead)
            Return bytesBuffer
        End Function

        ''' <summary>
        ''' Retrieve the state object and the client socket from the asynchronous state object.
        ''' </summary>
        ''' <param name="ar"></param>
        Private Sub ReceiveCallback(ar As IAsyncResult)
            Dim state As StateObject = DirectCast(ar.AsyncState, StateObject)
            Dim bytesBuffer = readDataBuffer(state, ar)

            If bytesBuffer.IsNullOrEmpty Then Return

            Call state.received.AddRange(bytesBuffer)

            Dim TempBuffer = state.received.ToArray
            Dim request = New RequestStream(TempBuffer)

            If Not request.FullRead Then Return

            Call state.received.Clear()

            If TempBuffer.Length > request.TotalBytes Then
                TempBuffer = TempBuffer.Skip(request.TotalBytes).ToArray
                ' 含有剩余的剪裁后的数据
                Call state.received.AddRange(TempBuffer)
            End If

            Try
                Call requestHandle(request)
            Catch ex As Exception
                ' 客户端处理数据的时候发生了内部错误
                Call ex.PrintException
                Call App.LogException(ex, MethodBase.GetCurrentMethod.GetFullName)
            End Try
        End Sub 'ReceiveCallback

        Private Sub requestHandle(request As RequestStream)
            If ServicesProtocol.Protocols.ServerHash = request.Protocol Then
                _MyServerHashCode = Scripting.CTypeDynamic(Of Integer)(request.GetUTF8String)
            Else
                Call RunTask(Sub() Call _MessageHandler(request))
            End If
        End Sub

        Private Sub waitReceive()
            Do While Not _EndReceive
                Call Thread.Sleep(1)
            Loop
        End Sub

        Public Class StateObject : Inherits Tcp.StateObject
            Public Stack As Integer
        End Class
#End Region

    End Class 'AsynchronousClient
End Namespace