LogStore.CreateLogArchiveSnapshot Metod

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

Returer

Ett LogArchiveSnapshot objekt som innehåller det tillstånd som krävs för att skapa ett arkiv.

Undantag

Exempel

I följande exempel visas hur du arkiverar ett LogStore till ett XML-dokument.

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

Parametrar

Returer

Ett LogArchiveSnapshot objekt som innehåller det tillstånd som krävs för att skapa ett arkiv.

Undantag

Kommentarer

Arkivögonblicksbilden som returneras från den här metoden omfattar information från antingen bassekvensnumret eller arkivsekvensnumret, beroende på vilket som är lägre, till det sista sekvensnumret. Det är inte inkluderande för det sista sekvensnumret, vilket innebär att arkivet endast innehåller poster upp till men inte sista. När du använder den här metoden måste dessutom startsekvensnumret vara lika med BaseSequenceNumber för att arkivet ska vara konsekvent.