连接缓存
建立与服务器的连接后,连接句柄会缓存在该进程的客户端计算机上,直到该连接关闭。 如果在后续连接中使用同一服务器、端口和凭据,且仅有 ADS_FAST_BIND 或 ADS_SERVER_BIND 身份验证标记不同,ADSI 则会重用此现有连接。 ADSI 会按进程执行此连接缓存操作。
若要提高性能,请尽可能重用现有连接。
下面是在 Visual Basic 中使用 IAD 的示例(另请参阅使用 IADs 接口):
Dim cachedConn As IADs
Dim obj As IADs
Dim cachedName As String
Dim objName As String
' Connect to the server and maintain this handle to cache the connection.
Set cachedConn = GetObject("LDAP://MyMachine/DC=MyDomain,DC=Fabrikam,DC=com")
cachedName = cachedConn.Get("distinguishedName")
Debug.Print (cachedName)
' Reuse the connection to MyMachine opened by cachedConn.
' Be aware that this line executes quickly because it is not required
' to transmit over the network again.
Set obj = GetObject("LDAP://MyMachine/CN=Bob,CN=Users,DC=MyDomain,DC=Fabrikam,DC=com")
objName = obj.Get("distinguishedName")
Debug.Print (objName)
' Release the second connection.
Set obj = Nothing
' Reuse the connection to MyMachine opened by cachedConn again.
Set obj = GetObject("LDAP://MyMachine/CN=Administrator,CN=Users,DC=MyDomain,DC=Fabrikam,DC=com")
objName = obj.Get("distinguishedName")
Debug.Print (objName)
' Release the second connection again.
Set obj = Nothing
' Release the first connection.
Set cachedConn = Nothing
' The connection to MyMachine is closed.
以下替代示例显示如何使用 .NET 中的 DirectoryEntry 对象进行连接缓存:
// Connect to the server and maintain this handle to cache the connection.
using (DirectoryEntry? cachedConn = new DirectoryEntry("LDAP://MyMachine/DC=MyDomain,DC=Fabrikam,DC=com"))
{
DirectoryEntry? secondConn;
string? cachedName;
string? objName;
cachedName = cachedConn.Properties["distinguishedName"].Value?.ToString();
Debug.WriteLine(cachedName);
// Reuse the connection to MyMachine opened by cachedConn.
// Be aware that this line executes quickly because it is not required
// to transmit over the network again.
using (secondConn = new DirectoryEntry("LDAP://MyMachine/CN=Bob,CN=Users,DC=MyDomain,DC=Fabrikam,DC=com"))
{
objName = secondConn.Properties["distinguishedName"].Value?.ToString();
Debug.WriteLine(objName);
// Release the second connection.
secondConn = null;
// Reuse the connection to MyMachine opened by cachedConn again.
secondConn = new DirectoryEntry("LDAP://MyMachine/CN=Administrator,CN=Users,DC=MyDomain,DC=Fabrikam,DC=com");
objName = secondConn.Properties["distinguishedName"].Value?.ToString();
Debug.WriteLine(objName);
}
// Release and dispose the second connection
}
// The connection to MyMachine is closed and disposed