// Notification raised before ADAL accesses the cache.
// This is your chance to update the in-memory copy from the DB, if the in-memory version is stale
async void BeforeAccessNotification(TokenCacheNotificationArgs args)
{
if (Cache == null)
{
// first time access
Cache = await PerWebUserCache.GetCache(new CacheUser(_userObjId, _hostName));
}
else
{
// retrieve last write from the DB
var dbCache = await PerWebUserCache.GetCache(new CacheUser(_userObjId, _hostName));
if (dbCache == null)
{
Cache = await PerWebUserCache.GetCache(new CacheUser(_userObjId, _hostName));
}
else
{
// if the in-memory copy is older than the persistent copy
if (dbCache.LastWrite > Cache.LastWrite)
{
// update in-memory copy
Cache = dbCache;
}
}
}
this.Deserialize((Cache == null) ? null : Utils.Decrypt(new EncryptedObj(Cache.CacheBits, Cache.Salt)));
}
// constructor
public AdalCosmosTokenCache(string userObjId, string hostName)
{
// associate the cache to the current user of the web app
_userObjId = userObjId;
_hostName = hostName;
this.AfterAccess = AfterAccessNotification;
this.BeforeAccess = BeforeAccessNotification;
// look up the entry in the DB
var task = Task.Run(async() => {
Cache = await PerWebUserCache.GetCache(new CacheUser(_userObjId, _hostName));
});
task.Wait();
try
{
// place the entry in memory
this.Deserialize((Cache == null) ? null : Utils.Decrypt(new EncryptedObj(Cache.CacheBits, Cache.Salt)));
}
catch (CryptographicException)
{
//token is invalid for decryption - delete it and start fresh
DeleteItem(Cache);
this.Deserialize(null);
}
catch (Exception ex)
{
throw ex;
}
}
