Compensator クラスとは何？わかりやすく解説 Weblio辞書

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Compensator クラス

すべての CRM (Compensating Resource Manager) Compensator の基本クラスを表します。

名前空間: System.EnterpriseServices.CompensatingResourceManager
アセンブリ: System.EnterpriseServices (system.enterpriseservices.dll 内)
構文

Visual Basic (宣言)

Public Class Compensator
    Inherits ServicedComponent

Visual Basic (使用法)

Dim instance As Compensator

public class Compensator : ServicedComponent

C++

public ref class Compensator : public
 ServicedComponent

public class Compensator extends ServicedComponent

JScript

public class Compensator extends
 ServicedComponent

解説

カスタムトランザクション Compensator を書き込むユーザーは、このオブジェクトを拡張します。

Compensator には、常にパブリックコンストラクタが存在している必要があります。それ以外の場合、リカバリエンジンではこれを作成できません。

詳細については、「方法 : コンペンセートリソースマネージャ (CRM) を作成する」を参照してください。

使用例

このクラスの使用方法のコード例を次に示します。

Visual Basic

' A CRM Compensator

Public Class AccountCompensator
    Inherits Compensator
    
    Private receivedPrepareRecord As Boolean
 = False
    
    
    Public Overrides Sub
 BeginPrepare() 
    
    End Sub 'BeginPrepare
    
    ' nothing to do
    Public Overrides Function
 PrepareRecord(ByVal log As LogRecord) As
 Boolean 
        
        ' Check the validity of the record.
        If log Is Nothing
 Then
            Return True
        End If
        Dim record As [Object]() = log.Record
        
        If record Is Nothing
 Then
            Return True
        End If
        If record.Length <> 2 Then
            Return True
        End If 
        ' The record is valid.
        receivedPrepareRecord = True
        Return False
    
    End Function 'PrepareRecord
    
    Public Overrides Function
 EndPrepare() As Boolean 
        ' Allow the transaction to proceed onlyif we have received a
 prepare record.
        If receivedPrepareRecord Then
            Return True
        Else
            Return False
        End If
    
    End Function 'EndPrepare
    
    Public Overrides Sub
 BeginCommit(ByVal commit As Boolean)
 
    
    End Sub 'BeginCommit
    
    ' nothing to do
    Public Overrides Function
 CommitRecord(ByVal log As LogRecord) As
 Boolean 
        ' nothing to do
        Return False
    
    End Function 'CommitRecord
    
    Public Overrides Sub
 EndCommit() 
    
    End Sub 'EndCommit
    
    ' nothing to do
    Public Overrides Sub
 BeginAbort(ByVal abort As Boolean)
 
    
    End Sub 'BeginAbort
    
    ' nothing to do
    Public Overrides Function
 AbortRecord(ByVal log As LogRecord) As
 Boolean 
        
        ' Check the validity of the record.
        If log Is Nothing
 Then
            Return True
        End If
        Dim record As [Object]() = log.Record
        
        If record Is Nothing
 Then
            Return True
        End If
        If record.Length <> 2 Then
            Return True
        End If 
        ' Extract old account data from the record.
        Dim filename As String
 = CStr(record(0))
        Dim balance As Integer
 = Fix(record(1))
        
        ' Restore the old state of the account.
        AccountManager.WriteAccountBalance(filename, balance)
        
        Return False
    
    End Function 'AbortRecord
    
    Public Overrides Sub
 EndAbort() 
    
    End Sub 'EndAbort
End Class 'AccountCompensator
 ' nothing to do

// A CRM Compensator
public class AccountCompensator : Compensator
{

    private bool receivedPrepareRecord = false;

    public override void BeginPrepare ()
    {
        // nothing to do
    }

    public override bool PrepareRecord (LogRecord
 log)
    {

        // Check the validity of the record.
        if (log == null) return(true);
        Object[] record = log.Record as Object[];
        if (record == null) return(true);
        if (record.Length != 2) return(true);

        // The record is valid.
        receivedPrepareRecord = true;
        return(false);              
    }

    public override bool EndPrepare ()
    {
        // Allow the transaction to proceed onlyif we have received
 a prepare record.
        if (receivedPrepareRecord)
        {
            return(true);
        }
        else
        {
            return(false);
        }
    }

    public override void BeginCommit (bool
 commit)
    {
        // nothing to do
    }

    public override bool CommitRecord (LogRecord
 log)
    {
        // nothing to do
        return(false);
    }

    public override void EndCommit ()
    {
        // nothing to do
    }

    public override void BeginAbort (bool
 abort)
    {
        // nothing to do
    }

    public override bool AbortRecord (LogRecord
 log)
    {

        // Check the validity of the record.
        if (log == null) return(true);
        Object[] record = log.Record as Object[];
        if (record == null) return(true);
        if (record.Length != 2) return(true);

        // Extract old account data from the record.
        string filename = (string) record[0];
        int balance = (int) record[1];
 
        // Restore the old state of the account.
        AccountManager.WriteAccountBalance(filename, balance);

        return(false);
    }

    public override void EndAbort ()
    {
        // nothing to do
    }    

}

C++

// A CRM Compensator
public ref class AccountCompensator : public
 Compensator
{
private:
    bool receivedPrepareRecord;

public:
    AccountCompensator()
    {
        receivedPrepareRecord = false;
    } 

public:
    virtual void BeginPrepare() override 
    {
        // nothing to do
    }

public:
    virtual bool PrepareRecord(LogRecord^ log) override 
    {

        // Check the validity of the record.
        if (log == nullptr)
        {
            return false;
        }
        array<Object^>^ record = dynamic_cast<array<Object^>^>(log->Record);
        if (record == nullptr)
        {
            return false;
        }
        if (record->Length != 2)
        {
            return false;
        }

        // The record is valid.
        receivedPrepareRecord = true;
        return true;              
    }

public:
    virtual bool EndPrepare() override
    {
        // Allow the transaction to proceed onlyif we have received
 a prepare
        // record.
        if (receivedPrepareRecord)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

public:
    virtual void BeginCommit(bool commit) override
    {
        // nothing to do
    }

public:
    virtual bool CommitRecord(LogRecord^ log) override
    {
        // nothing to do
        return(false);
    }

public:
    virtual void EndCommit() override
    {
        // nothing to do
    }

public:
    virtual void BeginAbort(bool abort) override
    {
        // nothing to do
    }

public:
    virtual bool AbortRecord(LogRecord^ log) override
    {

        // Check the validity of the record.
        if (log == nullptr)
        {
            return true;
        }
        array<Object^>^ record = dynamic_cast<array<Object^>^>(log->Record);
        if (record == nullptr)
        {
            return true;
        }
        if (record->Length != 2)
        {
            return true;
        }

        // Extract old account data from the record.
        String^ filename = (String^) record[0];
        int balance = (int) record[1];

        // Restore the old state of the account.
        WriteAccountBalance(filename, balance);

        return false;
    }

public:
    virtual void EndAbort() override
    {
        // nothing to do
    }    

};

// A CRM Compensator
public class AccountCompensator extends Compensator
{
    private boolean receivedPrepareRecord = false;

    public void BeginPrepare()
    {
        // nothing to do
    } //BeginPrepare    

    public boolean PrepareRecord(LogRecord log)
    {
        // Check the validity of the record.
        if (log == null) {
            return true;
        }
        Object record[] = new Object[] { log.get_Record() };

        if (record == null) {
            return true;
        }
        if (record.get_Length() != 2) {
            return true;
        }
        // The record is valid.
        receivedPrepareRecord = true;
        return false;
    } //PrepareRecord

    public boolean EndPrepare()
    {
        // Allow the transaction to proceed onlyif we have received
        // a prepare record.
        if (receivedPrepareRecord) {
            return true;
        }
        else {
            return false;
        }
    } //EndPrepare

    public void BeginCommit(boolean commit)
    {
        // nothing to do
    } //BeginCommit    

    public boolean CommitRecord(LogRecord log)
    {
        // nothing to do
        return false;
    } //CommitRecord

    public void EndCommit()
    {
        // nothing to do
    } //EndCommit    

    public void BeginAbort(boolean abort)
    {
        // nothing to do
    } //BeginAbort   

    public boolean AbortRecord(LogRecord log)
    {
        // Check the validity of the record.
        if (log == null) {
            return true;
        }
        Object record[] = new Object[] { log.get_Record() };

        if (record == null) {
            return true;
        }
        if (record.get_Length() != 2) {
            return true;
        }
        // Extract old account data from the record.
        String fileName = (String)(record.get_Item(0));
        int balance = System.Convert.ToInt32(record[1]);

        // Restore the old state of the account.
        AccountManager.WriteAccountBalance(fileName, balance);

        return false;
    } //AbortRecord

    public void EndAbort()
    {
        // nothing to do
    } //EndAbort
} //AccountCompensator

この Compensator は、次のワーカークラスで使用されます。

Visual Basic

' 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 Class 'Account

// 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();
        }
      
    }

}

C++

// 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
/** @attribute Transaction()
 */
public class Account extends ServicedComponent
{
    // A data member for the account file name.
    /** @property 
     */
    private String fileName;
    
    public String get_fileName()
    {
        return fileName;
    } //get_fileName
    
    public void set_fileName(String value)
    {
        fileName = value;
    } //set_fileName

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

    /** @property 
     */
    public boolean get_AllowCommit()
    {
        return commit;
    } //get_AllowCommit

    /** @property 
     */
    public void set_AllowCommit(boolean value)
    {
        commit = value;
    } //set_AllowCommit

    // Debit the account, 
    public void DebitAccount(int
 ammount)
    {
        // Create a new clerk using the AccountCompensator class.
        Clerk clerk = new Clerk(AccountCompensator.class.ToType()
,
            "An account transaction compensator",
            CompensatorOptions.AllPhases);

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

        Object record[] = new Object[2];
        record.set_Item(0, fileName);
        record.set_Item(1,(Int32)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();
        }
    } //DebitAccount 
} //Account

この Compensator とワーカーを実行するクライアントを次のコード例に示します。

Visual Basic

Imports System



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 'Main 
End Class 'CrmClient

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();
        }
          
    }

}

C++

#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;
    }

}

import System.*;

public class CrmClient
{
    public static void main(String[]
 args)
    {
        // Create a new account object. The object is created in a COM+
        // server application.
        Account account = new Account();

        // Transactionally debit the account.
        try {
            account.set_fileName(System.IO.Path.GetFullPath("JohnDoe"));
            account.set_AllowCommit(true);
            account.DebitAccount(3);
        }
        finally {
            account.Dispose();
        }
    } //main
} //CrmClient

継承階層

System.Object
   System.MarshalByRefObject
     System.ContextBoundObject
       System.EnterpriseServices.ServicedComponent
        System.EnterpriseServices.CompensatingResourceManager.Compensator

スレッドセーフ

この型の public static (Visual Basic では Shared) メンバはすべて、スレッドセーフです。インスタンスメンバの場合は、スレッドセーフであるとは限りません。

プラットフォーム

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition