/// <summary>
/// Gets the memory cache key to use for the cachekey specified.
/// </summary>
/// <param name="originalKey">The original key.</param>
/// <param name="keepMemoryCacheKey">if set to <c>true</c> it will keep the key in the storage</param>
/// <param name="duration">The duration, if available, the cachekey is valid. Only used if keepMemoryCacheKey is true. If TimeSpan.Zero, it's considered
/// not available/specified</param>
/// <param name="tag">The tag, if available. Only used if keepMemoryCacheKey is true.</param>
/// <returns>
/// the string equivalent of the guid associated with the cachekey specified
/// </returns>
private string GetMemoryCacheKey(CacheKey originalKey, bool keepMemoryCacheKey, TimeSpan duration, string tag)
{
Guid toReturn = Guid.Empty;
using (TimedLock.Lock(_semaphore))
{
if (!_cacheKeyToMemoryCacheKey.TryGetValue(originalKey, out toReturn))
{
toReturn = Guid.NewGuid();
if (keepMemoryCacheKey)
{
_cacheKeyToMemoryCacheKey.Add(originalKey, toReturn);
if (!string.IsNullOrEmpty(tag))
{
_cacheKeysPerTag.Add(tag, originalKey);
}
if (duration != TimeSpan.Zero)
{
_cacheKeysAndExpireDates.Add(new ValuePair <CacheKey, DateTime>(originalKey, DateTime.Now.ToUniversalTime().Add(duration)));
}
}
}
}
return(toReturn.ToString());
}
/// <summary>
/// Retrieves for all available sections all forums with all relevant statistical information. This information is stored per forum in an
/// AggregatedForumRow instance. The forum instances are indexed under their sectionid. Only forums which are vieable by the user are returned.
/// </summary>
/// <param name="availableSections">SectionCollection with all available sections</param>
/// <param name="accessableForums">List of accessable forums IDs.</param>
/// <param name="forumsWithThreadsFromOthers">The forums for which the calling user can view other users' threads. Can be null</param>
/// <param name="userId">The userid of the calling user.</param>
/// <returns>
/// MultiValueHashtable with per key (sectionID) a set of AggregatedForumRow instance, one row per forum in the section. If a section contains no forums
/// displayable to the user it's not present in the returned hashtable.
/// </returns>
public static async Task <MultiValueHashtable <int, AggregatedForumRow> > GetAllAvailableForumsAggregatedData(EntityCollection <SectionEntity> availableSections,
List <int> accessableForums,
List <int> forumsWithThreadsFromOthers, int userId)
{
var toReturn = new MultiValueHashtable <int, AggregatedForumRow>();
// return an empty list, if the user does not have a valid list of forums to access
if (accessableForums == null || accessableForums.Count <= 0)
{
return(toReturn);
}
// fetch all forums with statistics in a dynamic list, while filtering on the list of accessable forums for this user.
// Create the filter separate of the query itself, as it's re-used multiple times.
var threadFilter = ThreadGuiHelper.CreateThreadFilter(forumsWithThreadsFromOthers, userId);
var qf = new QueryFactory();
var q = qf.Create()
.Select(() => new AggregatedForumRow()
{
ForumID = ForumFields.ForumID.ToValue <int>(),
ForumName = ForumFields.ForumName.ToValue <string>(),
ForumDescription = ForumFields.ForumDescription.ToValue <string>(),
ForumLastPostingDate = ForumFields.ForumLastPostingDate.ToValue <DateTime?>(),
// add a scalar query which retrieves the # of threads in the specific forum.
// this will result in the query:
// (
// SELECT COUNT(ThreadID) FROM Thread
// WHERE ForumID = Forum.ForumID AND threadfilter.
// ) As AmountThreads
AmountThreads = qf.Create()
.Select(ThreadFields.ThreadID.Count())
.CorrelatedOver(ThreadFields.ForumID.Equal(ForumFields.ForumID))
.Where(threadFilter)
.ToScalar().As("AmountThreads").ToValue <int>(),
// add a scalar query which retrieves the # of messages in the threads of this forum.
// this will result in the query:
// (
// SELECT COUNT(MessageID) FROM Message
// WHERE ThreadID IN
// (
// SELECT ThreadID FROM Thread WHERE ForumID = Forum.ForumID AND threadfilter
// )
// ) AS AmountMessages
AmountMessages = qf.Create()
.Select(MessageFields.MessageID.Count())
.Where(MessageFields.ThreadID.In(
qf.Create()
.Select(ThreadFields.ThreadID)
.CorrelatedOver(ThreadFields.ForumID.Equal(ForumFields.ForumID))
.Where(threadFilter)))
.ToScalar().As("AmountMessages").ToValue <int>(),
HasRSSFeed = ForumFields.HasRSSFeed.ToValue <bool>(),
SectionID = ForumFields.SectionID.ToValue <int>()
})
.Where(ForumFields.ForumID.In(accessableForums))
.OrderBy(ForumFields.OrderNo.Ascending(), ForumFields.ForumName.Ascending())
.CacheResultset(Globals.DefaultCacheDurationOfResultsets);
using (var adapter = new DataAccessAdapter())
{
var results = await adapter.FetchQueryAsync(q).ConfigureAwait(false);
foreach (var forum in results)
{
toReturn.Add(forum.SectionID, forum);
}
}
return(toReturn);
}
