Sincronizar el proveedor de sincronización de archivos con otros proveedores

Artículo
10/17/2009

Este tema describe cómo crear una aplicación administrada que habilita un proveedor de sincronización de archivos para que sincronice con otro proveedor de Sync Framework. En este caso, el otro proveedor es un proveedor simple, pero también podría usar un proveedor personalizado estándar. Para obtener más información sobre los proveedores simples, vea Implementar un proveedor simple personalizado.

Hay dos requisitos principales para la aplicación:

La aplicación debe implementar IFileDataRetriever como la interfaz de transferencia de datos entre dos proveedores.
El proveedor simple debe usar para los identificadores el mismo formato que usa el proveedor de sincronización de archivos: un GUID de 16 bytes para identificadores de réplica; un GUID de 16 bytes que es precedido por un prefijo de 8 bytes para identificadores de elemento; y un entero de 4 bytes para identificadores de unidad de cambio.

Ejemplos de código administrado

El ejemplo de esta sección muestra parte de código que es relevante para sincronizar un proveedor de sincronización de archivos y un proveedor simple, con el énfasis en los requisitos del identificador y de la interfaz de transferencia. Para ver este código en el contexto de una aplicación completa, vea la aplicación "Sync 101 - Synchronizing a File Synchronization Provider with a Simple Provider" que está disponible en la galería de códigos.

El siguiente ejemplo de código muestra cómo la definición de la propiedad IdFormats para el proveedor simple coincide con los requisitos establecidos anteriormente.

public override SyncIdFormatGroup IdFormats
{
    get
    {
        SyncIdFormatGroup idFormats = new SyncIdFormatGroup();
        idFormats.ItemIdFormat.Length = 24;
        idFormats.ItemIdFormat.IsVariableLength = false;
        idFormats.ReplicaIdFormat.Length = 16;
        idFormats.ReplicaIdFormat.IsVariableLength = false;
        idFormats.ChangeUnitIdFormat.Length = 4;
        idFormats.ChangeUnitIdFormat.IsVariableLength = false;

        return idFormats;
    }
}

Public Overrides ReadOnly Property IdFormats() As SyncIdFormatGroup
    Get
        Dim FormatGroup As New SyncIdFormatGroup()

        FormatGroup.ItemIdFormat.Length = 24
        FormatGroup.ItemIdFormat.IsVariableLength = False
        FormatGroup.ReplicaIdFormat.Length = 16
        FormatGroup.ReplicaIdFormat.IsVariableLength = False
        FormatGroup.ChangeUnitIdFormat.Length = 4
        FormatGroup.ChangeUnitIdFormat.IsVariableLength = False

        Return FormatGroup
    End Get
End Property

Los siguientes ejemplos de código muestran dos de los métodos requeridos para los proveedores simples LoadChangeData y InsertItem. Gran parte del código de estos métodos es específico para la implementación de un proveedor simple, pero hay dos áreas que hay que tener en cuenta:

LoadChangeData se usa para cargar datos que han sido enumerados desde el almacén local (el almacén que es servido por el proveedor simple). Este método devuelve datos como un objeto SimpleFileDataRetriever, que es la implementación del ejemplo de IFileDataRetriever.

public override object LoadChangeData(ItemFieldDictionary keyAndExpectedVersion,
    IEnumerable<SyncId> changeUnitsToLoad,
    RecoverableErrorReportingContext recoverableErrorReportingContext)
{
    // Figure out which item is being asked for

    string localRelativePath;
    long expectedLMT;
    ParseDictionary(keyAndExpectedVersion, out localRelativePath, out expectedLMT);

    string localPath = Path.Combine(this.rootFolder, localRelativePath);
    string currentVersion = File.GetLastWriteTimeUtc(localPath).Ticks.ToString();

    // Check if it changed --- race condition!

    if (File.GetLastWriteTimeUtc(localPath).Ticks != expectedLMT)
    {
        recoverableErrorReportingContext.RecordRecoverableErrorForChange(
            new RecoverableErrorData(null));
        return null;
    }

    // Return
    return new SimpleFileDataRetriever(localRelativePath, null, localPath, File.GetAttributes(localPath));
}

Public Overrides Function LoadChangeData(ByVal keyAndExpectedVersion As ItemFieldDictionary, ByVal changeUnitsToLoad As IEnumerable(Of SyncId), ByVal recoverableErrorReportingContext As RecoverableErrorReportingContext) As Object
    ' Figure out which item is being asked for 

    Dim localRelativePath As String = ""
    Dim expectedLMT As Long
    ParseDictionary(keyAndExpectedVersion, localRelativePath, expectedLMT)

    Dim localPath As String = Path.Combine(Me.rootFolder, localRelativePath)
    Dim currentVersion As String = File.GetLastWriteTimeUtc(localPath).Ticks.ToString()

    ' Check if it changed --- race condition! 

    If File.GetLastWriteTimeUtc(localPath).Ticks <> expectedLMT Then
        recoverableErrorReportingContext.RecordRecoverableErrorForChange(Nothing)
        Return Nothing
    End If

    ' Return 
    Return New SimpleFileDataRetriever(localRelativePath, Nothing, localPath, File.GetAttributes(localPath))
End Function

InsertItem se usa para insertar datos en el almacén local desde el almacén remoto (el almacén que es servido por el proveedor de sincronización de archivos). Este método convierte los datos de elemento que recibe en un objeto IFileDataRetriever. El método InsertItem también convierte los datos.

public override void InsertItem(object itemData,
    IEnumerable<SyncId> changeUnitsToCreate,
    RecoverableErrorReportingContext recoverableErrorReportingContext,
    out ItemFieldDictionary keyAndUpdatedVersion,
    out bool commitKnowledgeAfterThisItem)
{
    // Figure out where to create it

    IFileDataRetriever fileData = (IFileDataRetriever)itemData;

    string localPath = Path.Combine(this.rootFolder, Path.Combine(fileData.RelativeDirectoryPath, fileData.FileData.Name));

    // Check if it is already there --- name collision

    if (File.Exists(localPath))
    {
        recoverableErrorReportingContext.RecordConstraintError(
            ConstructDictionary(Path.Combine(fileData.RelativeDirectoryPath, fileData.FileData.Name)));

        keyAndUpdatedVersion = null;
        commitKnowledgeAfterThisItem = false;

        return;
    }

    // Create it

    File.Copy(fileData.AbsoluteSourceFilePath, localPath);

    // Return particulars to Simple Provider framework

    keyAndUpdatedVersion = ConstructDictionary(
        Path.Combine(fileData.RelativeDirectoryPath, fileData.FileData.Name),
        File.GetLastWriteTimeUtc(localPath).Ticks);

    commitKnowledgeAfterThisItem = false;
}

Public Overrides Sub InsertItem(ByVal itemData As Object, ByVal changeUnitsToCreate As IEnumerable(Of SyncId), ByVal recoverableErrorReportingContext As RecoverableErrorReportingContext, ByRef keyAndUpdatedVersion As ItemFieldDictionary, ByRef commitKnowledgeAfterThisItem As Boolean)
    ' Figure out where to create it 

    Dim fileData As IFileDataRetriever = DirectCast(itemData, IFileDataRetriever)

    Dim localPath As String = Path.Combine(Me.rootFolder, Path.Combine(fileData.RelativeDirectoryPath, fileData.FileData.Name))

    ' Check if it is already there --- name collision 

    If File.Exists(localPath) Then
        recoverableErrorReportingContext.RecordConstraintError(ConstructDictionary(Path.Combine(fileData.RelativeDirectoryPath, fileData.FileData.Name)))

        keyAndUpdatedVersion = Nothing
        commitKnowledgeAfterThisItem = False

        Exit Sub
    End If

    ' Create it 

    File.Copy(fileData.AbsoluteSourceFilePath, localPath)

    ' Return particulars to Simple Provider framework 

    keyAndUpdatedVersion = ConstructDictionary(Path.Combine(fileData.RelativeDirectoryPath, fileData.FileData.Name), File.GetLastWriteTimeUtc(localPath).Ticks)

    commitKnowledgeAfterThisItem = False
End Sub

El ejemplo de código siguiente crea la clase SimpleFileDataRetriever, que usa AbsoluteSourceFilePath y RelativeDirectoryPath para identificar las ubicaciones de archivo, y FileData y FileStream para transferir los datos actuales.

class SimpleFileDataRetriever : IFileDataRetriever, IDisposable
{
    private string _relativeLocalFilePath;
    private Stream _sourceStream;
    private string _absoluteSourceFilePath;
    private FileAttributes _attributes;

    public SimpleFileDataRetriever(string relativeLocalFilePath, Stream sourceStream, string absoluteSourceFilePath, FileAttributes attributes)
    { 
        this._relativeLocalFilePath = relativeLocalFilePath;
        this._sourceStream = sourceStream;
        this._attributes = attributes;
        this._absoluteSourceFilePath = absoluteSourceFilePath;
    }

    #region IFileDataRetriever Members

    // If the local store has no concept of absolute file path then return a NotImplementedException here.  
    // The FSP will instead use the stream for file copying.
    // If implemented, return absolute local path including file name.
    public string AbsoluteSourceFilePath
    {
        get 
        { 
            return this._absoluteSourceFilePath; 
        }
    }

    public FileData FileData
    {
        get
        {
            FileInfo fi = new FileInfo(_absoluteSourceFilePath);

            //For the relative path on FileData, provide relative path including file name
            return new FileData(
                _relativeLocalFilePath,
                _attributes,
                fi.CreationTimeUtc,
                fi.LastAccessTimeUtc,
                fi.LastWriteTimeUtc,
                fi.Length);
        }
    }

    public System.IO.Stream FileStream
    {
        get 
        {
            if (this._sourceStream == null)
            {
                this._sourceStream = new FileStream(this._absoluteSourceFilePath, FileMode.Open);
            }

            return _sourceStream; 
        }
    }

    // Must return the relative path without the filename
    public string RelativeDirectoryPath
    {
        get
        {
            return Path.GetDirectoryName(_relativeLocalFilePath);
        }
    }

    #endregion

    #region IDisposable Members

    public void Dispose()
    {
        if (this._sourceStream != null)
        {
            this._sourceStream.Close();
        }
    }

    #endregion
}

    Class SimpleFileDataRetriever
        Implements IFileDataRetriever
        '        Implements IDisposable
        Private _relativeLocalFilePath As String
        Private _sourceStream As Stream
        Private _absoluteSourceFilePath As String
        Private _attributes As FileAttributes

        Public Sub New(ByVal relativeLocalFilePath As String, ByVal sourceStream As Stream, ByVal absoluteSourceFilePath As String, ByVal attributes As FileAttributes)
            Me._relativeLocalFilePath = relativeLocalFilePath
            Me._sourceStream = sourceStream
            Me._attributes = attributes
            Me._absoluteSourceFilePath = absoluteSourceFilePath
        End Sub

#Region "IFileDataRetriever Members"

        ' If the local store has no concept of absolute file path then return a NotImplementedException here. 
        ' The FSP will instead use the stream for file copying. 
        ' If implemented, return absolute local path including file name. 
        Public ReadOnly Property AbsoluteSourceFilePath() As String Implements IFileDataRetriever.AbsoluteSourceFilePath
            Get
                Return Me._absoluteSourceFilePath
            End Get
        End Property

        Public ReadOnly Property FileData() As FileData Implements IFileDataRetriever.FileData
            Get
                Dim fi As New FileInfo(_absoluteSourceFilePath)

                'For the relative path on FileData, provide relative path including file name 
                Return New FileData(_relativeLocalFilePath, _attributes, fi.CreationTimeUtc, fi.LastAccessTimeUtc, fi.LastWriteTimeUtc, fi.Length)
            End Get
        End Property

        Public ReadOnly Property FileStream() As System.IO.Stream Implements IFileDataRetriever.FileStream
            Get
                If Me._sourceStream Is Nothing Then
                    Me._sourceStream = New FileStream(Me._absoluteSourceFilePath, FileMode.Open)
                End If

                Return _sourceStream
            End Get
        End Property

        ' Must return the relative path without the filename 
        Public ReadOnly Property RelativeDirectoryPath() As String Implements IFileDataRetriever.RelativeDirectoryPath
            Get
                Return Path.GetDirectoryName(_relativeLocalFilePath)
            End Get
        End Property

#End Region

#Region "IDisposable Members"

        Public Sub Dispose()
            If Me._sourceStream IsNot Nothing Then
                Me._sourceStream.Close()
            End If
        End Sub

#End Region
    End Class

El código de ejemplo siguiente sincroniza los dos proveedores. El proceso de sincronización es el mismo que si sincronizara dos proveedores de sincronización o dos proveedores simples: implementar la interfaz IFileDataRetriever y usar los formatos de identificador apropiados asegura que los datos se transfieran de la manera correcta.

static void DoBidirectionalSync(string pathA, Guid replicaA, string pathB, Guid replicaB)
{
    SyncOperationStatistics stats;
    MySimpleFileProvider providerA = new MySimpleFileProvider(replicaA, pathA);
    FileSyncProvider providerB = new FileSyncProvider(replicaB, pathB);

    //Set the custom provider's conflict resolution policy to custom in order to show 
    //how to perform complex resolution actions.
    providerA.Configuration.ConflictResolutionPolicy = ConflictResolutionPolicy.ApplicationDefined;

    //Register callbacks so that we can handle conflicts if they are detected, and other events.
    RegisterCallbacks(providerA);
    RegisterCallbacks(providerB);

    //Synchronize the two providers that are specified.           
    Console.WriteLine("Sync {0} and {1}...", pathA, pathB);
    SyncOrchestrator agent = new SyncOrchestrator();

    //To avoid writing conflict resolution logic in your matching provider it is good practice to always sync from custom provider
    //to FSP provider first.  That way the FSP will handle all the conflicts itself.  Here we do the opposite to show our custom
    //constraint conflict resolution.
    agent.Direction = SyncDirectionOrder.UploadAndDownload;

    agent.LocalProvider = providerB;
    agent.RemoteProvider = providerA;
    stats = agent.Synchronize();

    //Display the statistics from the SyncOperationStatistics object that is returned 
    //by Synchronize().
    Console.WriteLine("Download Applied:\t {0}", stats.DownloadChangesApplied);
    Console.WriteLine("Download Failed:\t {0}", stats.DownloadChangesFailed);
    Console.WriteLine("Download Total:\t\t {0}", stats.DownloadChangesTotal);
    Console.WriteLine("Upload Total:\t\t {0}", stats.UploadChangesApplied);
    Console.WriteLine("Upload Total:\t\t {0}", stats.UploadChangesFailed);
    Console.WriteLine("Upload Total:\t\t {0}", stats.UploadChangesTotal);
}

Private Shared Sub DoBidirectionalSync(ByVal pathA As String, ByVal replicaA As Guid, ByVal pathB As String, ByVal replicaB As Guid)
    Dim stats As SyncOperationStatistics
    Dim providerA As New MySimpleFileProvider(replicaA, pathA)
    Dim providerB As New FileSyncProvider(replicaB, pathB)

    'Set the custom provider's conflict resolution policy to custom in order to show 
    'how to perform complex resolution actions. 
    providerA.Configuration.ConflictResolutionPolicy = ConflictResolutionPolicy.ApplicationDefined

    'Register callbacks so that we can handle conflicts if they are detected, and other events. 
    RegisterCallbacks(providerA)
    RegisterCallbacks(providerB)

    'Synchronize the two providers that are specified. 
    Console.WriteLine("Sync {0} and {1}...", pathA, pathB)
    Dim agent As New SyncOrchestrator()

    'To avoid writing conflict resolution logic in your matching provider it is good practice to always sync from custom provider 
    'to FSP provider first. That way the FSP will handle all the conflicts itself. Here we do the opposite to show our custom 
    'constraint conflict resolution. 
    agent.Direction = SyncDirectionOrder.UploadAndDownload

    agent.LocalProvider = providerB
    agent.RemoteProvider = providerA
    stats = agent.Synchronize()

    'Display the statistics from the SyncOperationStatistics object that is returned 
    'by Synchronize(). 
    Console.WriteLine("Download Applied:" & vbTab & " {0}", stats.DownloadChangesApplied)
    Console.WriteLine("Download Failed:" & vbTab & " {0}", stats.DownloadChangesFailed)
    Console.WriteLine("Download Total:" & vbTab & vbTab & " {0}", stats.DownloadChangesTotal)
    Console.WriteLine("Upload Total:" & vbTab & vbTab & " {0}", stats.UploadChangesApplied)
    Console.WriteLine("Upload Total:" & vbTab & vbTab & " {0}", stats.UploadChangesFailed)
    Console.WriteLine("Upload Total:" & vbTab & vbTab & " {0}", stats.UploadChangesTotal)
End Sub

Vea también

Conceptos

Implementar un proveedor simple personalizado
Integrar datos de proveedores diferentes
Sincronizar archivos

Compartir a través de

Sincronizar el proveedor de sincronización de archivos con otros proveedores

Ejemplos de código administrado

Vea también

Conceptos

Recursos adicionales