public CacheSubscription(ISubscription subscription, CoreItemCacheParams cacheParams, SubscriptionCallback userCallback, object userContext)
{
Subscription = subscription;
CacheParams = cacheParams;
UserCallback = userCallback;
UserContext = userContext;
}
// ------------------------------ load single item methods ------------------------------
private ICoreItem LoadItem(string itemName, CoreItemCacheParams cacheParams)
{
ICoreItem result = Cache.Get(itemName, LoadSaveType.Default, cacheParams);
if (result != null)
{
if (!result.IsCurrent())
{
result = null;
}
}
NotifyUserDataChange(Cache.GetUpdates());
return(result);
}
// subscriptions
private ISubscription SubscribePrivate(
Type dataType, IExpression filter,
bool excludeExisting, bool waitForExisting, bool excludeDataBody,
SubscriptionCallback userCallback, object userContext)
{
if (dataType == null)
{
throw new ArgumentNullException(nameof(dataType));
}
if (filter == null)
{
throw new ArgumentNullException(nameof(filter));
}
// create subscription
ISubscription subscription = Client.CreateTypedSubscription(dataType, filter);
subscription.UserCallback = SubscriptionCallback;
subscription.UserContext = null;
subscription.ItemKind = ItemKind.Object;
subscription.ExcludeExisting = excludeExisting;
subscription.WaitForExisting = waitForExisting;
subscription.ExcludeDataBody = excludeDataBody;
var userParams = new CoreItemCacheParams(dataType, subscription.Id);
_Subscriptions.Set(subscription.Id, new CacheSubscription(subscription, userParams, userCallback, userContext));
// hack - todo - do initial load if required (remove when server supports waitForExisting)
const long minimumUSN = 0;
if (!excludeExisting)
{
List <ICoreItem> items = Client.LoadItems(dataType, ItemKind.Object, filter, 0, true);
foreach (var newItem in items)
{
Cache.Put(newItem.Name, newItem, LoadSaveType.Avoid, userParams, TimeSpan.MaxValue);
}
// notify user
NotifyUserDataChange(Cache.GetUpdates());
}
// start subscription
subscription.MinimumUSN = minimumUSN;
//_Logger.LogDebug("Cache: Creating subscription[{0}]: <{1}> {2} ({3})",
// filter.GetHashCode(), dataType.FullName,
// filter.DisplayString(), subscription.Id);
subscription.Start();
return(subscription);
}
// ------------------------------ load multiple items methods ------------------------------
public List <ICoreItem> LoadItems <T>(IEnumerable <string> itemNames)
{
var cacheParams = new CoreItemCacheParams(typeof(T), Guid.Empty);
return(itemNames.Select(itemName => LoadItem(itemName, cacheParams)).Where(item => item != null).ToList());
}
