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Clerk Class

  • Reference

Definition

Namespace:
System.EnterpriseServices.CompensatingResourceManager
Assembly:
System.EnterpriseServices.dll

Writes records of transactional actions to a log.

public ref class Clerk sealed
public sealed class Clerk
type Clerk = class
Public NotInheritable Class Clerk
Inheritance
Object
Clerk

Examples

The following code example demonstrates the use of this class.

// A CRM Worker
[Transaction]
public ref class Account : public ServicedComponent
{

    // A data member for the account file name.
private:
    String^ filenameValue;

public:
    property String^ Filename
    {
        String^ get()
        {
            return filenameValue;
        }
        void set( String^ value )
        {
            filenameValue = value;
        }
    }

    // A boolean data member that determines whether to commit or abort the 
    // transaction.
private:
    bool allowCommitValue;

public:
    property bool AllowCommit
    {
        bool get()
        {
            return allowCommitValue;
        }
        void set( bool value )
        {
            allowCommitValue = value;
        }
    }

    // Debit the account, 
public:
    void DebitAccount(int amount)
    {

        // Create a new clerk using the AccountCompensator class.
        Clerk^ clerk = gcnew Clerk(AccountCompensator::typeid,
            "An account transaction compensator", CompensatorOptions::AllPhases);

        // Create a record of previous account status, and deliver it to the
        // clerk.
        int balance = ReadAccountBalance(Filename);

        array<Object^>^ record = gcnew array<Object^>(2);
        record[0] = Filename;
        record[1] = balance;

        clerk->WriteLogRecord(record);
        clerk->ForceLog();

        // Perform the transaction
        balance -= amount;

        Console::WriteLine("{0}: {1}", Filename, balance);

        WriteAccountBalance(Filename, balance);

        // Commit or abort the transaction 
        if (AllowCommit)
        {
            ContextUtil::SetComplete();
        }
        else
        {
            ContextUtil::SetAbort();
        }

    }

};

// A CRM Worker
[Transaction]
public class Account : ServicedComponent
{

    // A data member for the account file name.
    private string filename;

    public string Filename
    {
        get
        {
            return(filename);
        }
        set
        {
            filename = value;
        }
    }

    // A boolean data member that determines whether to commit or abort the transaction.
    private bool commit;

    public bool AllowCommit
    {
        get
        {
            return(commit);
        }
        set
        {
            commit = value;
        }
    }

    // Debit the account,
    public void DebitAccount (int ammount)
    {

        // Create a new clerk using the AccountCompensator class.
        Clerk clerk = new Clerk(typeof(AccountCompensator),
          "An account transaction compensator", CompensatorOptions.AllPhases);

        // Create a record of previous account status, and deliver it to the clerk.
        int balance = AccountManager.ReadAccountBalance(filename);

    Object[] record = new Object[2];
    record[0] = filename;
        record[1] = balance;

        clerk.WriteLogRecord(record);
        clerk.ForceLog();

        // Perform the transaction
        balance -= ammount;
        AccountManager.WriteAccountBalance(filename, balance);

        // Commit or abort the transaction
        if (commit)
        {
            ContextUtil.SetComplete();
        }
        else
        {
            ContextUtil.SetAbort();
        }
    }
}

' A CRM Worker
<Transaction()>  _
Public Class Account
    Inherits ServicedComponent
    
    ' A data member for the account file name.
    Private filename As String
    
    
    Public Property Filenam() As String
        Get
            Return Filename
        End Get
        Set(ByVal value As String)
            filename = Value
        End Set
    End Property
    
    
    ' A boolean data member that determines whether to commit or abort the transaction.
    Private commit As Boolean
    
    
    Public Property AllowCommit() As Boolean 
        Get
            Return commit
        End Get
        Set
            commit = value
        End Set
    End Property
    
    
    
    
    ' Debit the account, 
    Public Sub DebitAccount(ByVal ammount As Integer) 
        
        ' Create a new clerk using the AccountCompensator class.
        Dim clerk As New Clerk(GetType(AccountCompensator), "An account transaction compensator", CompensatorOptions.AllPhases)
        ' Create a record of previous account status, and deliver it to the clerk.
        Dim balance As Integer = AccountManager.ReadAccountBalance(Filenam)
        
        Dim record(1) As [Object]
        record(0) = filename
        record(1) = balance
        
        clerk.WriteLogRecord(record)
        clerk.ForceLog()
        ' Perform the transaction
        balance -= ammount
        AccountManager.WriteAccountBalance(filename, balance)
        
        ' Commit or abort the transaction 
        If commit Then
            ContextUtil.SetComplete()
        Else
            ContextUtil.SetAbort()
        End If
    End Sub
    
End Class

The following code example demonstrates the corresponding Compensator class.

#using "System.EnterpriseServices.dll"

using namespace System;

[assembly: System::Reflection::AssemblyKeyFile("CrmServer.key")];

int main ()
{

    // Create a new account object. The object is created in a COM+ server application.
    Account^ account = gcnew Account();

    // Transactionally debit the account.
    try
    {
        account->Filename = System::IO::Path::GetFullPath("JohnDoe");
        account->AllowCommit = true;
        account->DebitAccount(3);
    }
    finally
    {
        delete account;
    }

}

using System;

public class CrmClient
{

    public static void Main ()
    {

        // Create a new account object. The object is created in a COM+ server application.
        Account account = new Account();

        // Transactionally debit the account.
        try
        {
            account.Filename = System.IO.Path.GetFullPath("JohnDoe");
            account.AllowCommit = true;
            account.DebitAccount(3);
        }
        finally
        {
            account.Dispose();
        }
    }
}

Public Class CrmClient
    
    
    Public Shared Sub Main() 
        
        ' Create a new account object. The object is created in a COM+ server application.
        Dim account As New Account()
        
        ' Transactionally debit the account.
        Try
            account.Filenam = System.IO.Path.GetFullPath("JohnDoe")
            account.AllowCommit = True
            account.DebitAccount(3)
        Finally
            account.Dispose()
        End Try
    
    End Sub
End Class

Remarks

Each clerk is associated with a compensator, which is called back to perform actions during the two-phase commit of the transaction.

Constructors

Clerk(String, String, CompensatorOptions)

Initializes a new instance of the Clerk class.
Clerk(Type, String, CompensatorOptions)

Initializes a new instance of the Clerk class.

Properties

LogRecordCount

Gets the number of log records.
TransactionUOW

Gets a value representing the transaction unit of work (UOW).

Methods

Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
Finalize()

Frees the resources of the current Clerk before it is reclaimed by the garbage collector.
ForceLog()

Forces all log records to disk.
ForceTransactionToAbort()

Performs an immediate abort call on the transaction.
ForgetLogRecord()

Does not deliver the last log record that was written by this instance of this interface.
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString()

Returns a string that represents the current object.

(Inherited from Object)
WriteLogRecord(Object)

Writes unstructured log records to the log.

Applies to