CustomStore.cs :  » Bloggers » dasBlog » ProviderCustomStore » C# / CSharp Open Source

using System;
using System.Data;
using System.Globalization;
using System.Security.Cryptography;
using DotNetOpenId;
using DotNetOpenId.RelyingParty;
using IProviderAssociationStoreDotNetOpenId.IAssociationStoreDotNetOpenId.AssociationRelyingPartyType;

namespace ProviderCustomStore{
  /// <summary>
  /// This custom store serializes all elements to demonstrate peristent and/or shared storage.
  /// This is common in a web farm, for example.
  /// </summary>
  /// <remarks>
  /// This doesn't actually serialize anything to a persistent store, so restarting the web server
  /// will still clear everything this store is supposed to remember.
  /// But we "persist" all associations and nonces into a DataTable to demonstrate
  /// that using a database is possible.
  /// </remarks>
  public class CustomStore : IProviderAssociationStore {
    public static CustomStore Instance = new CustomStore();
    public CustomStoreDataSet dataSet = new CustomStoreDataSet();

    #region IAssociationStore<AssociationRelyingPartyType> Members

    public void StoreAssociation(AssociationRelyingPartyType distinguishingFactor, Association assoc) {
      var assocRow = dataSet.Association.NewAssociationRow();
      assocRow.DistinguishingFactor = distinguishingFactor.ToString();
      assocRow.Handle = assoc.Handle;
      assocRow.Expires = assoc.Expires.ToLocalTime();
      assocRow.PrivateData = assoc.SerializePrivateData();
      dataSet.Association.AddAssociationRow(assocRow);
    }

    public Association GetAssociation(AssociationRelyingPartyType distinguishingFactor) {
      // properly escape the URL to prevent injection attacks.
      string value = distinguishingFactor.ToString();
      string filter = string.Format(CultureInfo.InvariantCulture, "{0} = '{1}'",
        dataSet.Association.DistinguishingFactorColumn.ColumnName, value);
      string sort = dataSet.Association.ExpiresColumn.ColumnName + " DESC";
      DataView view = new DataView(dataSet.Association, filter, sort, DataViewRowState.CurrentRows);
      if (view.Count == 0) return null;
      var row = (CustomStoreDataSet.AssociationRow)view[0].Row;
      return Association.Deserialize(row.Handle, row.Expires.ToUniversalTime(), row.PrivateData);
    }

    public Association GetAssociation(AssociationRelyingPartyType distinguishingFactor, string handle) {
      var assocRow = dataSet.Association.FindByDistinguishingFactorHandle(distinguishingFactor.ToString(), handle);
      return Association.Deserialize(assocRow.Handle, assocRow.Expires, assocRow.PrivateData);
    }

    public bool RemoveAssociation(AssociationRelyingPartyType distinguishingFactor, string handle) {
      var row = dataSet.Association.FindByDistinguishingFactorHandle(distinguishingFactor.ToString(), handle);
      if (row != null) {
        dataSet.Association.RemoveAssociationRow(row);
        return true;
      } else {
        return false;
      }
    }

    public void ClearExpiredAssociations() {
      removeExpiredRows(dataSet.Association, dataSet.Association.ExpiresColumn.ColumnName);
    }

    #endregion

    void removeExpiredRows(DataTable table, string expiredColumnName) {
      string filter = string.Format(CultureInfo.InvariantCulture, "{0} < #{1}#",
        expiredColumnName, DateTime.Now);
      DataView view = new DataView(table, filter, null, DataViewRowState.CurrentRows);
      for (int i = view.Count - 1; i >= 0; i--)
        view.Delete(i);
    }

  }
}