cWinsock 最佳实践

📖 目录

性能优化
错误处理
安全建议
调试技巧
常见陷阱

性能优化

1️⃣ 事件处理优化

避免在事件处理中执行耗时操作

' ❌ 错误：在事件中处理大量数据
Private Sub m_oServer_DataArrival(Client As cWinsock, ByVal bytesTotal As Long)
    Dim sData As String
    Client.GetData sData
    
    ' 在事件中进行耗时操作
    ProcessLargeData sData ' 可能耗时很久
    SaveToDatabase sData     ' 可能超时
End Sub

' ✅ 正确：将耗时操作放入队列
Private m_oWorkQueue As Collection

Private Sub m_oServer_DataArrival(Client As cWinsock, ByVal bytesTotal As Long)
    Dim sData As String
    Client.GetData sData
    
    ' 添加到工作队列
    m_oWorkQueue.Add Array(Client.Tag, sData)
    
    ' 定时器处理队列
    tmrWorkQueue_Timer
End Sub

Private Sub tmrWorkQueue_Timer()
    Dim vItem As Variant
    Dim sTag As String
    Dim sData As String
    
    If m_oWorkQueue.Count > 0 Then
        vItem = m_oWorkQueue(1)
        sTag = vItem(0)
        sData = vItem(1)
        
        ' 处理数据
        ProcessData sTag, sData
        
        ' 从队列移除
        m_oWorkQueue.Remove 1
    End If
End Sub

2️⃣ 缓冲区大小优化

根据应用场景调整缓冲区大小

' 小数据频繁传输
Private Const SMALL_BUFFER_SIZE As Long = 1024 ' 1KB

' 大数据块传输
Private Const LARGE_BUFFER_SIZE As Long = 65536 ' 64KB

' 文件传输
Private Const FILE_CHUNK_SIZE As Long = 8192 ' 8KB

' 使用示例
Private Sub SendOptimal(ByVal sData As String)
    Dim lSize As Long
    lSize = Len(sData)
    
    If lSize < SMALL_BUFFER_SIZE Then
        ' 小数据，直接发送
        m_oClient.SendData sData
    Else
        ' 大数据，分块发送
        Dim lOffset As Long
        lOffset = 1
        
        Do While lOffset <= lSize
            Dim sChunk As String
            sChunk = Mid$(sData, lOffset, FILE_CHUNK_SIZE)
            
            m_oClient.SendData sChunk
            lOffset = lOffset + FILE_CHUNK_SIZE
            
            ' 等待发送完成
            Do While m_bSending
                DoEvents
            Loop
        Loop
    End If
End Sub

3️⃣ 连接池管理

对于需要频繁建立连接的场景，使用连接池

' 连接池类
Private Type tConnection
    Socket As cWinsock
    InUse As Boolean
    LastUsed As Date
End Type

Private m_oConnections() As tConnection
Private m_lPoolSize As Long

' 初始化连接池
Private Sub InitConnectionPool(ByVal lSize As Long)
    ReDim m_oConnections(0 To lSize - 1) As tConnection
    m_lPoolSize = lSize
    
    Dim i As Long
    For i = 0 To lSize - 1
        Set m_oConnections(i).Socket = New cWinsock
        m_oConnections(i).InUse = False
        m_oConnections(i).LastUsed = Now
    Next
End Sub

' 获取连接
Private Function GetConnection() As cWinsock
    Dim i As Long
    
    ' 查找可用连接
    For i = 0 To m_lPoolSize - 1
        If Not m_oConnections(i).InUse Then
            If m_oConnections(i).Socket.State = sckConnected Then
                m_oConnections(i).InUse = True
                Set GetConnection = m_oConnections(i).Socket
                Exit Function
            End If
        End If
    Next
    
    ' 没有可用连接，返回 Nothing
    Set GetConnection = Nothing
End Function

' 释放连接
Private Sub ReleaseConnection(ByVal oSocket As cWinsock)
    Dim i As Long
    For i = 0 To m_lPoolSize - 1
        If m_oConnections(i).Socket Is oSocket Then
            m_oConnections(i).InUse = False
            m_oConnections(i).LastUsed = Now
            Exit For
        End If
    Next
End Sub

4️⃣ 批量发送优化

' 批量发送
Private Sub SendBatch(ByVal vData() As Variant)
    Const BATCH_SIZE As Long = 100
    
    Dim lStart As Long
    lStart = LBound(vData)
    
    Do While lStart <= UBound(vData)
        Dim lEnd As Long
        lEnd = Min(lStart + BATCH_SIZE - 1, UBound(vData))
        
        Dim lBatchCount As Long
        lBatchCount = lEnd - lStart + 1
        
        ' 一次性发送多个数据包（使用分隔符）
        Dim i As Long
        Dim sBatch As String
        
        For i = lStart To lEnd
            sBatch = sBatch & vData(i) & vbCrLf
        Next
        
        m_oClient.SendData sBatch
        
        ' 等待发送完成
        Do While m_bSending
            DoEvents
        Loop
        
        lStart = lEnd + 1
    Loop
End Sub

错误处理

1️⃣ 统一错误处理

' 错误处理模块
Public Enum ErrorLevel
    elInfo = 0
    elWarning = 1
    elError = 2
    elCritical = 3
End Enum

' 统一错误日志
Public Sub LogError(ByVal eLevel As ErrorLevel, ByVal sSource As String, ByVal sMessage As String, ByVal lErrNum As Long)
    Dim sPrefix As String
    
    Select Case eLevel
        Case elInfo:      sPrefix = "[INFO]"
        Case elWarning:   sPrefix = "[WARN]"
        Case elError:     sPrefix = "[ERROR]"
        Case elCritical:  sPrefix = "[CRIT]"
    End Select
    
    Dim sLog As String
    sLog = Format$(Now, "yyyy-mm-dd hh:mm:ss") & " " & sPrefix & " [" & sSource & "] " & sMessage & " (Error " & lErrNum & ")"
    
    Debug.Print sLog
    
    ' 写入文件
    WriteToLogFile sLog
End Sub

' 使用示例
Private Sub m_oClient_Error(Client As cWinsock, ByVal Number As Long, Description As String, ByVal Scode As Long)
    LogError elError, "Client", Description, Number
    
    Select Case Number
        Case 10053, 10054
            ' 连接关闭，正常
            LogError elInfo, "Client", "连接被远程关闭", Number
            
        Case 10060
            ' 连接超时
            LogError elWarning, "Client", "连接超时", Number
            
        Case Else
            ' 其他错误
            LogError elError, "Client", Description, Number
    End Select
End Sub

2️⃣ 重试机制

' 带重试的操作
Private Function DoWithRetry(ByVal sFuncName As String, ByVal lMaxRetries As Long, ByVal vFunc As Variant) As Boolean
    Dim lRetry As Long
    Dim bSuccess As Boolean
    
    For lRetry = 1 To lMaxRetries
        On Error Resume Next
        bSuccess = CallByName(vFunc, sFuncName, VbMethod)
        
        If bSuccess And Err.Number = 0 Then
            LogError elInfo, "Retry", sFuncName & " 成功 (尝试 " & lRetry & "/" & lMaxRetries & ")", 0
            DoWithRetry = True
            Exit Function
        End If
        
        LogError elWarning, "Retry", sFuncName & " 失败 (尝试 " & lRetry & "/" & lMaxRetries & ")", Err.Number
        
        ' 等待后重试
        Sleep 1000 * lRetry
    Next
    
    LogError elError, "Retry", sFuncName & " 失败，超过最大重试次数", 0
    DoWithRetry = False
End Function

' 使用示例
Private Function SendDataWithRetry(ByVal sData As String) As Boolean
    On Error Resume Next
    m_oClient.SendData sData
    SendDataWithRetry = (Err.Number = 0)
End Function

Private Sub SendImportantData(ByVal sData As String)
    If Not DoWithRetry("SendDataWithRetry", 3, Me) Then
        LogError elCritical, "Send", "无法发送重要数据", 0
    End If
End Sub

3️⃣ 资源清理

' 确保资源清理
Private Sub SafeCloseSocket(ByRef oSocket As cWinsock)
    On Error Resume Next
    
    If Not oSocket Is Nothing Then
        If oSocket.State <> sckClosed Then
            oSocket.Close_
            Debug.Print "Socket 已关闭"
        End If
        Set oSocket = Nothing
    End If
End Sub

' 窗体卸载时清理所有资源
Private Sub Form_Unload(Cancel As Integer)
    On Error Resume Next
    
    ' 关闭所有 socket
    SafeCloseSocket m_oClient
    SafeCloseSocket m_oServer
    SafeCloseSocket m_oUdp
    
    ' 停止所有定时器
    tmrHeartbeat.Enabled = False
    tmrCleanup.Enabled = False
    
    ' 清理集合
    Set m_oWorkQueue = Nothing
    Set m_oClients = Nothing
    
    Debug.Print "所有资源已清理"
End Sub

安全建议

1️⃣ 连接验证

' 连接前验证
Private Function ValidateConnection(ByVal sHost As String, ByVal lPort As Long) As Boolean
    ' 检查白名单
    If Not IsWhitelisted(sHost) Then
        LogError elWarning, "Security", sHost & " 不在白名单中", 0
        ValidateConnection = False
        Exit Function
    End If
    
    ' 检查端口范围
    If lPort < 1024 Or lPort > 65535 Then
        LogError elWarning, "Security", "端口 " & lPort & " 超出允许范围", 0
        ValidateConnection = False
        Exit Function
    End If
    
    ' 检查连接数限制
    If m_oServer.ClientCount >= MAX_CONNECTIONS Then
        LogError elWarning, "Security", "达到最大连接数", 0
        ValidateConnection = False
        Exit Function
    End If
    
    ValidateConnection = True
End Function

' 使用
Private Sub m_oServer_ConnectionRequest(Client As cWinsock, ByRef DisConnect As Boolean)
    If Not ValidateConnection(Client.RemoteHostIP, Client.RemotePort) Then
        DisConnect = True
    End If
End Sub

2️⃣ 数据验证

' 验证接收的数据
Private Function ValidateData(ByVal sData As String) As Boolean
    ' 检查长度
    If Len(sData) > MAX_DATA_SIZE Then
        LogError elWarning, "Security", "数据大小超过限制", 0
        ValidateData = False
        Exit Function
    End If
    
    ' 检查危险字符
    If InStr(sData, "<script") > 0 Or InStr(sData, "javascript:") > 0 Then
        LogError elWarning, "Security", "检测到危险内容", 0
        ValidateData = False
        Exit Function
    End If
    
    ' 自定义验证
    If Not CustomValidation(sData) Then
        ValidateData = False
        Exit Function
    End If
    
    ValidateData = True
End Function

' 使用
Private Sub m_oServer_DataArrival(Client As cWinsock, ByVal bytesTotal As Long)
    Dim sData As String
    Client.GetData sData
    
    If Not ValidateData(sData) Then
        LogError elError, "Security", "拒绝无效数据", 0
        Client.Close_
        Exit Sub
    End If
    
    ' 处理数据
    ProcessData sData
End Sub

3️⃣ 防止缓冲区溢出

' 限制缓冲区大小
Private Const MAX_BUFFER_SIZE As Long = 1048576 ' 1MB

Private Sub m_oClient_DataArrival(Client As cWinsock, ByVal bytesTotal As Long)
    ' 检查缓冲区大小
    If Client.BytesReceived > MAX_BUFFER_SIZE Then
        LogError elCritical, "Security", "缓冲区溢出，关闭连接", 0
        Client.Close_
        Exit Sub
    End If
    
    ' 读取数据
    Dim sData As String
    Client.GetData sData
End Sub

4️⃣ 速率限制

' 速率限制
Private Type tRateLimit
    Window As Date
    RequestCount As Long
End Type

Private m_oRateLimits As Collection
Private Const MAX_REQUESTS_PER_MINUTE As Long = 60

Private Function CheckRateLimit(ByVal sIP As String) As Boolean
    Dim tLimit As tRateLimit
    On Error Resume Next
    tLimit = m_oRateLimits(sIP)
    
    ' 如果是新 IP，创建记录
    If Err.Number <> 0 Then
        tLimit.Window = Now
        tLimit.RequestCount = 0
        m_oRateLimits.Add tLimit, sIP
    End If
    
    ' 检查时间窗口
    If DateDiff("s", tLimit.Window, Now) > 60 Then
        ' 超过 1 分钟，重置
        tLimit.Window = Now
        tLimit.RequestCount = 0
    End If
    
    ' 检查请求数
    If tLimit.RequestCount >= MAX_REQUESTS_PER_MINUTE Then
        LogError elWarning, "Security", sIP & " 超过速率限制", 0
        CheckRateLimit = False
    Else
        tLimit.RequestCount = tLimit.RequestCount + 1
        m_oRateLimits.Remove sIP
        m_oRateLimits.Add tLimit, sIP
        CheckRateLimit = True
    End If
End Function

' 使用
Private Sub m_oServer_ConnectionRequest(Client As cWinsock, ByRef DisConnect As Boolean)
    If Not CheckRateLimit(Client.RemoteHostIP) Then
        DisConnect = True
    End If
End Sub

调试技巧

1️⃣ 详细的日志记录

' 日志级别
Public Enum LogLevel
    llDebug = 0
    llInfo = 1
    llWarning = 2
    llError = 3
End Enum

Public m_eLogLevel As LogLevel

' 带级别的日志
Public Sub Log(ByVal eLevel As LogLevel, ByVal sSource As String, ByVal sMessage As String)
    If eLevel < m_eLogLevel Then Exit Sub
    
    Dim sPrefix As String
    Select Case eLevel
        Case llDebug:   sPrefix = "[DEBUG]"
        Case llInfo:    sPrefix = "[INFO]"
        Case llWarning:  sPrefix = "[WARN]"
        Case llError:    sPrefix = "[ERROR]"
    End Select
    
    Dim sLog As String
    sLog = Format$(Now, "hh:mm:ss") & " " & sPrefix & " [" & sSource & "] " & sMessage
    
    Debug.Print sLog
    
    ' 写入日志文件
    WriteLogToFile sLog
End Sub

' 使用
Private Sub m_oClient_Connect(Client As cWinsock)
    Log llInfo, "Client", "已连接到 " & Client.RemoteHostIP & ":" & Client.RemotePort
End Sub

Private Sub m_oClient_DataArrival(Client As cWinsock, ByVal bytesTotal As Long)
    Log llDebug, "Client", "收到 " & bytesTotal & " 字节"
    
    Dim sData As String
    Client.GetData sData
    
    Log llDebug, "Client", "数据内容: " & Left$(sData, 100) ' 只记录前 100 字符
End Sub

2️⃣ 数据包捕获

' 数据包捕获
Private Type tPacketCapture
    Timestamp As Date
    Direction As String ' "IN" or "OUT"
    Data As String
    Size As Long
End Type

Private m_oPackets As Collection

Private Sub CapturePacket(ByVal sDir As String, ByVal sData As String)
    Dim tPacket As tPacketCapture
    
    tPacket.Timestamp = Now
    tPacket.Direction = sDir
    tPacket.Data = Left$(sData, 200) ' 限制长度
    tPacket.Size = Len(sData)
    
    m_oPackets.Add tPacket
    
    Debug.Print "[" & sDir & "] " & Format$(tPacket.Timestamp, "hh:mm:ss") & " " & Len(sData) & " bytes"
End Sub

' 使用
Private Sub m_oClient_DataArrival(Client As cWinsock, ByVal bytesTotal As Long)
    Dim sData As String
    Client.GetData sData
    
    CapturePacket "IN", sData
End Sub

Private Sub cmdSend_Click()
    Dim sData As String
    sData = txtSend.Text
    
    m_oClient.SendData sData
    CapturePacket "OUT", sData
End Sub

3️⃣ 性能监控

' 性能统计
Private Type tPerformanceStats
    TotalPackets As Long
    TotalBytes As Long
    StartTime As Date
    PacketsPerSecond As Double
    BytesPerSecond As Double
End Type

Private m_oStats As tPerformanceStats

' 初始化统计
Private Sub InitStats()
    m_oStats.TotalPackets = 0
    m_oStats.TotalBytes = 0
    m_oStats.StartTime = Now
End Sub

' 更新统计
Private Sub UpdateStats(ByVal lBytes As Long)
    m_oStats.TotalPackets = m_oStats.TotalPackets + 1
    m_oStats.TotalBytes = m_oStats.TotalBytes + lBytes
    
    Dim lElapsed As Double
    lElapsed = DateDiff("s", m_oStats.StartTime, Now)
    
    If lElapsed > 0 Then
        m_oStats.PacketsPerSecond = m_oStats.TotalPackets / lElapsed
        m_oStats.BytesPerSecond = m_oStats.TotalBytes / lElapsed
    End If
End Sub

' 显示统计
Private Sub ShowStats()
    Debug.Print "===== 性能统计 ====="
    Debug.Print "运行时间: " & DateDiff("s", m_oStats.StartTime, Now) & " 秒"
    Debug.Print "总包数: " & m_oStats.TotalPackets
    Debug.Print "总字节数: " & m_oStats.TotalBytes
    Debug.Print "包/秒: " & Format$(m_oStats.PacketsPerSecond, "0.00")
    Debug.Print "字节/秒: " & Format$(m_oStats.BytesPerSecond, "0.00")
    Debug.Print "=================="
End Sub

常见陷阱

1️⃣ 忘记 `DoEvents`

' ❌ 错误：长时间处理会阻塞 UI
Private Sub m_oServer_DataArrival(Client As cWinsock, ByVal bytesTotal As Long)
    Dim sData As String
    Client.GetData sData
    
    ' 长时间操作，UI 会冻结
    ProcessLargeData sData
End Sub

' ✅ 正确：定期释放控制权
Private Sub m_oServer_DataArrival(Client As cWinsock, ByVal bytesTotal As Long)
    Dim sData As String
    Client.GetData sData
    
    Dim i As Long
    For i = 1 To 1000
        ProcessDataChunk sData, i
        
        ' 定期释放控制权
        If i Mod 10 = 0 Then
            DoEvents
        End If
    Next
End Sub

2️⃣ 内存泄漏

' ❌ 错误：不及时释放对象
Private Sub ProcessClients()
    Dim oClient As cWinsock
    For Each oClient In m_oServer.Clients
        Dim oData As New CDataObject
        oData.Data = "xxx"
        
        ' oData 没有释放
    Next
End Sub

' ✅ 正确：及时释放
Private Sub ProcessClients()
    Dim oClient As cWinsock
    For Each oClient In m_oServer.Clients
        Dim oData As New CDataObject
        oData.Data = "xxx"
        
        ' 使用后立即释放
        Set oData = Nothing
    Next
End Sub

3️⃣ 忽略状态检查

' ❌ 错误：不检查状态就操作
Private Sub cmdSend_Click()
    m_oClient.SendData "Hello" ' 可能失败
End Sub

' ✅ 正确：先检查状态
Private Sub cmdSend_Click()
    If m_oClient.State = sckConnected Then
        m_oClient.SendData "Hello"
    Else
        MsgBox "未连接", vbExclamation
    End If
End Sub

4️⃣ 错误的编码使用

' ❌ 错误：编码不一致
m_oClient.SendData "中文", ScpUtf8  ' UTF-8
' 接收时
Client.GetData sData  ' 默认 ACP → 乱码

' ✅ 正确：保持一致
m_oClient.SendData "中文", ScpUtf8  ' UTF-8
' 接收时
Client.GetData sData, , , ScpUtf8  ' UTF-8

最后更新: 2026-01-09

cWinsock 最佳实践 ​

📖 目录 ​

性能优化 ​

1️⃣ 事件处理优化 ​

2️⃣ 缓冲区大小优化 ​

3️⃣ 连接池管理 ​

4️⃣ 批量发送优化 ​

错误处理 ​

1️⃣ 统一错误处理 ​

2️⃣ 重试机制 ​

3️⃣ 资源清理 ​

安全建议 ​

1️⃣ 连接验证 ​

2️⃣ 数据验证 ​

3️⃣ 防止缓冲区溢出 ​

4️⃣ 速率限制 ​

调试技巧 ​

1️⃣ 详细的日志记录 ​

2️⃣ 数据包捕获 ​

3️⃣ 性能监控 ​

常见陷阱 ​

1️⃣ 忘记 DoEvents ​

2️⃣ 内存泄漏 ​

3️⃣ 忽略状态检查 ​

4️⃣ 错误的编码使用 ​

cWinsock 最佳实践

📖 目录

性能优化

1️⃣ 事件处理优化

2️⃣ 缓冲区大小优化

3️⃣ 连接池管理

4️⃣ 批量发送优化

错误处理

1️⃣ 统一错误处理

2️⃣ 重试机制

3️⃣ 资源清理

安全建议

1️⃣ 连接验证

2️⃣ 数据验证

3️⃣ 防止缓冲区溢出

4️⃣ 速率限制

调试技巧

1️⃣ 详细的日志记录

2️⃣ 数据包捕获

3️⃣ 性能监控

常见陷阱

1️⃣ 忘记 `DoEvents`

2️⃣ 内存泄漏

3️⃣ 忽略状态检查

4️⃣ 错误的编码使用