LogStore.CreateLogArchiveSnapshot Methode

public:
 System::IO::Log::LogArchiveSnapshot ^ CreateLogArchiveSnapshot();

public System.IO.Log.LogArchiveSnapshot CreateLogArchiveSnapshot();

member this.CreateLogArchiveSnapshot : unit -> System.IO.Log.LogArchiveSnapshot

Public Function CreateLogArchiveSnapshot () As LogArchiveSnapshot

Gibt zurück

Ein LogArchiveSnapshot Objekt, das den Zustand enthält, der zum Erstellen eines Archivs erforderlich ist.

Ausnahmen

Beispiele

Das folgende Beispiel zeigt, wie sie ein LogStore XML-Dokument archivieren.

class LogBackup
{
    static void ArchiveToXML(LogStore logStore, string fileName)
    {
        LogArchiveSnapshot snapshot = logStore.CreateLogArchiveSnapshot();

        XmlTextWriter writer = new XmlTextWriter(fileName, Encoding.ASCII);

        writer.WriteStartElement("logArchive");
        foreach(FileRegion region in snapshot.ArchiveRegions)
        {
            writer.WriteStartElement("fileRegion");
            writer.WriteElementString("path", region.Path);
            writer.WriteElementString("length", region.FileLength.ToString());
            writer.WriteElementString("offset", region.Offset.ToString());
            using(Stream dataStream = region.GetStream())
            {
                byte[] data = new byte[dataStream.Length];
                dataStream.Read(data, 0, data.Length);
                writer.WriteElementString("data", Convert.ToBase64String(data));
            }
            writer.WriteEndElement();
        }
        writer.WriteEndElement();
        writer.Close();
        logStore.SetArchiveTail(snapshot.LastSequenceNumber);
    }
    static void RestoreFromXML(string fileName)
    {
        using(XmlTextReader reader = new XmlTextReader(fileName))
        {
            reader.ReadStartElement("logArchive");
            while(reader.IsStartElement())
            {
                string path = reader.ReadElementString("path");
                long length = Int64.Parse(reader.ReadElementString("length"));
                long offset = Int64.Parse(reader.ReadElementString("offset"));
                string dataString = reader.ReadElementString("data");
                byte[] data = Convert.FromBase64String(dataString);
                FileStream fileStream;
                using(fileStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write))
                {
                    fileStream.SetLength(length);
                    fileStream.Position = offset; fileStream.Write(data, 0, data.Length);
                }
            }
        reader.ReadEndElement();
        }
    }
}

Friend Class LogBackup
    Private Shared Sub ArchiveToXML(ByVal logStore As LogStore, ByVal fileName As String)
        Dim snapshot As LogArchiveSnapshot = logStore.CreateLogArchiveSnapshot()

        Dim writer As New XmlTextWriter(fileName, Encoding.ASCII)

        writer.WriteStartElement("logArchive")
        For Each region As FileRegion In snapshot.ArchiveRegions
            writer.WriteStartElement("fileRegion")
            writer.WriteElementString("path", region.Path)
            writer.WriteElementString("length", region.FileLength.ToString())
            writer.WriteElementString("offset", region.Offset.ToString())
            Using dataStream As Stream = region.GetStream()
                Dim data(dataStream.Length - 1) As Byte
                dataStream.Read(data, 0, data.Length)
                writer.WriteElementString("data", Convert.ToBase64String(data))
            End Using
            writer.WriteEndElement()
        Next region
        writer.WriteEndElement()
        writer.Close()
        logStore.SetArchiveTail(snapshot.LastSequenceNumber)

    End Sub
    Private Shared Sub RestoreFromXML(ByVal fileName As String)
        Using reader As New XmlTextReader(fileName)
            reader.ReadStartElement("logArchive")
            Do While reader.IsStartElement()
                Dim path = reader.ReadElementString("path")
                Dim length = Int64.Parse(reader.ReadElementString("length"))
                Dim offset = Int64.Parse(reader.ReadElementString("offset"))
                Dim dataString = reader.ReadElementString("data")
                Dim data() = Convert.FromBase64String(dataString)
                Dim fileStream As FileStream
                fileStream = New FileStream(path, FileMode.OpenOrCreate, FileAccess.Write)
                Using fileStream
                    fileStream.SetLength(length)
                    fileStream.Position = offset
                    fileStream.Write(data, 0, data.Length)
                End Using
            Loop
            reader.ReadEndElement()
        End Using
    End Sub
End Class

public:
 System::IO::Log::LogArchiveSnapshot ^ CreateLogArchiveSnapshot(System::IO::Log::SequenceNumber first, System::IO::Log::SequenceNumber last);

public System.IO.Log.LogArchiveSnapshot CreateLogArchiveSnapshot(System.IO.Log.SequenceNumber first, System.IO.Log.SequenceNumber last);

member this.CreateLogArchiveSnapshot : System.IO.Log.SequenceNumber * System.IO.Log.SequenceNumber -> System.IO.Log.LogArchiveSnapshot

Public Function CreateLogArchiveSnapshot (first As SequenceNumber, last As SequenceNumber) As LogArchiveSnapshot

Parameter

Gibt zurück

Ein LogArchiveSnapshot Objekt, das den Zustand enthält, der zum Erstellen eines Archivs erforderlich ist.

Ausnahmen

Hinweise

Die von dieser Methode zurückgegebene Archivmomentaufnahme umfasst Informationen aus der Basissequenznummer oder der Archivsequenznummer, je nachdem, welcher Wert niedriger ist, auf die letzte Sequenznummer. Es ist nicht inklusive für die letzte Sequenznummer, was bedeutet, dass das Archiv nur Datensätze bis zu, aber nicht zuletzt enthält. Darüber hinaus muss bei Verwendung dieser Methode der Startsequenzwert gleich der BaseSequenceNumber sein, damit das Archiv konsistent ist.