Best collection for keep objects sorted and remove by key

Question

I have events and timestamp of the events. I want to keep objects sorted on timestamp. And i want to remove old objects every minutes. Since objects already sorted on timestamp i think RemoveLesserThenKey like function will work best.

I checked sortedlist but it seems it doesnt have such function. Can you give me any advice?

Do i have to write my own sorted list?

EDIT:
1-Events do not come according to time.
2-I want a collection to use sorting structure(Like BST) to remove objects.

does the timestamp change over time or is it immutable? Are objects added to the collection in timestamp order? — D Stanley, Jun 02 '16 at 18:12
yes object will be sorted on timestamp. i edited question again. — fyo, Jun 02 '16 at 18:14
It sounds like you want a priority queue, there isn't an implementation in the BCL. — Lee, Jun 02 '16 at 18:14
See http://stackoverflow.com/questions/102398/priority-queue-in-net in regards to priority queue. OrderedBag and OrderedSet classes may be what you need. — Justin Loveless, Jun 02 '16 at 18:17
As the events do not come according to time, could it happen that an event arrives with a timestamp earlier than the old objects which have been deleted? — Andrew Morton, Jun 02 '16 at 18:27
I already check this situation somewhere else. But, they will be deleted next minute anyway. — fyo, Jun 02 '16 at 18:31

score 1 · Answer 1 · edited Jun 02 '16 at 18:24

1

SortedDictionary<TKey, TValue> is Your friend

edited Jun 02 '16 at 18:24

Erik Philips

48,663
7
112
142

answered Jun 02 '16 at 18:21

Jacek Cz

1,799
1
13
22

1

Since OP seemed like he wanted a specific function to remove lesser keys, I'd just like to add that this could be accomplished simply by iterating through the keys and removing entries after a certain point where items are considered old. He could have also accomplished this with a `SortedList` by removing entries starting at a certain index, but since he is working with data that is not coming in sorted the `SortedDictionary` is the best choice between the two. – Justin Loveless Jun 02 '16 at 18:30
Yes, I can remove objects until a condition has met. Since my condition is only about key values, there should be faster way to remove objects. Just removing left branch of the BST kind of way. – fyo Jun 02 '16 at 18:40
Does this count as link only? More details to flesh the answer out as to _how_ to use this would be good – D. Ben Knoble Jun 02 '16 at 18:59

Lee Painton · Answer 2 · 2016-06-03T00:58:46.943

I think you would best off writing your own sorted linked list for this. Insertions could be done in worst case O(n) time and removing all nodes below a certain threshold would be a simple linear time operation.

As you suggested you could also use a BST. You'd just have to remember to set a new root every time you did a batch removal.

Edit: In thinking about this, a BST would wind up very unbalanced to the right after a few insert/delete rounds. It may not offer much in the way of time savings over a linked list.

Best collection for keep objects sorted and remove by key

2 Answers2