public void CreateSharedLock(int contentId, string @lock)
{
var timeLimit = DateTime.UtcNow.AddTicks(-SharedLockTimeout.Ticks);
var row = SharedLocks.FirstOrDefault(x => x.ContentId == contentId);
if (row != null && row.CreationDate < timeLimit)
{
SharedLocks.Remove(row);
row = null;
}
if (row == null)
{
var newSharedLockId = SharedLocks.Count == 0 ? 1 : SharedLocks.Max(t => t.SharedLockId) + 1;
SharedLocks.Add(new SharedLockRow
{
SharedLockId = newSharedLockId,
ContentId = contentId,
Lock = @lock,
CreationDate = DateTime.UtcNow
});
return;
}
if (row.Lock != @lock)
{
throw new LockedNodeException(null, $"The node (#{contentId}) is locked by another shared lock.");
}
row.CreationDate = DateTime.UtcNow;
}
private void DeleteTimedOutItems()
{
var timeLimit = DateTime.UtcNow.AddTicks(-SharedLockTimeout.Ticks);
var timedOutItems = SharedLocks.Where(x => x.CreationDate < timeLimit).ToArray();
foreach (var item in timedOutItems)
{
SharedLocks.Remove(item);
}
}
public string RefreshSharedLock(int contentId, string @lock)
{
DeleteTimedOutItems();
var row = SharedLocks.FirstOrDefault(x => x.ContentId == contentId);
if (row == null)
{
throw new SharedLockNotFoundException("Content is unlocked");
}
if (row.Lock != @lock)
{
throw new LockedNodeException(null, $"The node (#{contentId}) is locked by another shared lock.");
}
row.CreationDate = DateTime.UtcNow;
return(row.Lock);
}
public string ModifySharedLock(int contentId, string @lock, string newLock)
{
DeleteTimedOutItems();
var existingItem = SharedLocks.FirstOrDefault(x => x.ContentId == contentId && x.Lock == @lock);
if (existingItem != null)
{
existingItem.Lock = newLock;
return(null);
}
var existingLock = SharedLocks.FirstOrDefault(x => x.ContentId == contentId)?.Lock;
if (existingLock == null)
{
throw new SharedLockNotFoundException("Content is unlocked");
}
if (existingLock != @lock)
{
throw new LockedNodeException(null, $"The node (#{contentId}) is locked by another shared lock.");
}
return(existingLock);
}
public void DeleteAllSharedLocks()
{
SharedLocks.Clear();
}
public string GetSharedLock(int contentId)
{
var timeLimit = DateTime.UtcNow.AddTicks(-SharedLockTimeout.Ticks);
return(SharedLocks.FirstOrDefault(x => x.ContentId == contentId && x.CreationDate >= timeLimit)?.Lock);
}