private void BeforeAccessNotification(TokenCacheNotificationArgs args)
{
System.Diagnostics.Debug.WriteLine($"BeforeAccessNotification for {User}");
// Look up the persisted entry
var persistedEntry = LoadPersistedCacheEntry();
if (CachedEntity == null)
{
// first time access
CachedEntity = persistedEntry;
System.Diagnostics.Debug.WriteLine($"BeforeAccessNotification for {User} - first time access");
}
else
{
// if the in-memory copy is older than the persistent copy
if (persistedEntry != null && persistedEntry.LastWrite > CachedEntity.LastWrite)
{
//// read from from storage, update in-memory copy
CachedEntity = persistedEntry;
System.Diagnostics.Debug.WriteLine($"BeforeAccessNotification for {User} - update in-memory cache");
}
}
if (null != CachedEntity)
{
System.Diagnostics.Debug.WriteLine($"BeforeAccessNotification for {User} - Deserialize cached entity");
this.Deserialize(CachedEntity.CacheBits);
}
else
{
System.Diagnostics.Debug.WriteLine($"BeforeAccessNotification for {User} - No cached entry exists");
this.Deserialize(null);
}
}
public AzureTableTokenCache(string user)
{
this.User = user;
this.AfterAccess = AfterAccessNotification;
this.BeforeAccess = BeforeAccessNotification;
this.BeforeWrite = BeforeWriteNotification;
CachedEntity = LoadPersistedCacheEntry();
this.Deserialize((CachedEntity == null) ? null : CachedEntity.CacheBits);
}
public override void Clear()
{
base.Clear();
var entry = LoadPersistedCacheEntry();
if (null != entry)
{
TableOperation delete = TableOperation.Delete(entry);
tables.UserTokenCacheTable.Execute(delete);
}
CachedEntity = null;
}
private void AfterAccessNotification(TokenCacheNotificationArgs args)
{
System.Diagnostics.Debug.WriteLine($"AfterAccessNotification for {User}");
if (this.HasStateChanged)
{
if (CachedEntity == null)
{
CachedEntity = new TokenCacheEntity();
}
CachedEntity.RowKey = User;
CachedEntity.CacheBits = this.Serialize();
CachedEntity.LastWrite = DateTime.Now;
TableOperation insert = TableOperation.InsertOrReplace(CachedEntity);
tables.UserTokenCacheTable.Execute(insert);
this.HasStateChanged = false;
System.Diagnostics.Debug.WriteLine($"Wrote value to persistent cache for {User}");
}
}