After a combination of List. RemoveAll and List. FindAll produces performance problems...

Original code:

Data Volume in entityList: 4704; length: 2

Private static void OperateRemove (List <Entity> entityList, int length ){

EntityList. RemoveAll (delegate (Entity entity ){
List <Entity> list = entityList. FindAll (delegate (Entity innerEntity ){
Return entity. A = innerEntity.

});
Return null! = List & list. Count <length;
});

}

Solution 1: it is initially considered that the data is not sorted, so FindAll will be slow. So

Private static void OperateRemove (List <Entity> entityList, int length ){

EntityList. Sort (delegate (Entity entity1, parameter roompriceentity entity2 ){
Return entity1.A. CompareTo (entity2.A );
});

EntityList. RemoveAll (delegate (Entity entity ){
List <Entity> list = entityList. FindAll (delegate (Entity innerEntity ){
Return entity. A = innerEntity.

});
Return null! = List & list. Count <length;
});

}

At that time, after the program ran, the microsecond time was: 7901

 

Solution 2: It seems that the problem bottleneck is still in FindAll. Therefore, you can search for the entity. A to be deleted in one query and then delete it in A centralized manner.

Private static void OperateRemove (List <Entity> entityList, int length ){

EntityList. Sort (delegate (Entity entity1, Entity entity2 ){
Return entity1.A. CompareTo (entity2.A );
});
Int eachACount = 0;
Int A = 0;
Int nextA = 0;
List <int> lackAEntityList = new List <int> ();
Foreach (Entity entity in entityList ){
If (0 = ){
A = entity.;
NextA = entity.;
}
Else {
NextA = entity.;
}
If (! = NextA ){
If (length> eachACount ){
LackAEntityList. Add (roomId );
}
A = nextA;
EachACount = 0;
}
EachACount ++;
}
EntityList. RemoveAll (delegate (Entity entity ){
Return lackAEntityList. Exists (delegate (int ){
Return entity. A =;
});
});

}

After the program ran,Microseconds: 40

 

Of course there are other solutions: such as using sortlist + binarySearch, Etc.

However, 40 is ideal for us.

 

Attached

Objectives:
/// Search for the RoomID in B-List as 0 based on the role ID in A-List,
/// Delete the configuration information about all roomids with null values in B-List.
/// You must also delete the information in A-List.

Public List <RoomEntity> RemoveRoomIDAllEmpty ()
{
/// Create a consumer idlist for storing a non-empty RoomID
List <Int32> incluidlist = new List <int> ();

RoomList. ForEach (delegate (RoomEntity re)
{
If (hotelList. Contains (re. Upload ID ))
{
If (re. roomId! = 0)
{
Repeated idlist. Add (re. Upload ID );
}
}
});

// Delete the configuration information about all roomids of the role ID that are empty in the RoomList.
RoomList. RemoveAll (delegate (RoomEntity re)
{
Return! Repeated idlist. Contains (re. Upload ID );
});

// Delete the corresponding information in HotelList
HotelList. RemoveAll (delegate (Int32 I)
{
Return! HotelIdList. Contains (I );
});

Return roomList;
}

List <Int32> hotelList = new List <Int32> {
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
};

List <RoomEntity> roomList = new List <RoomEntity> {
New RoomEntity {role id = 1, roomId = 1111 },
New RoomEntity {role id = 1, roomId = 0 },
New RoomEntity {role id = 1, roomId = 1111 },
New RoomEntity {role id = 1, roomId = 0 },
New RoomEntity {role id = 1, roomId = 1111 },
New RoomEntity {role id = 2, roomId = 0 },
New RoomEntity {role id = 2, roomId = 0 },
New RoomEntity {role id = 2, roomId = 0 },
New RoomEntity {role id = 2, roomId = 0 },
New RoomEntity {role id = 4, roomId = 1111 },
New RoomEntity {role id = 5, roomId = 1111 },
New RoomEntity {role id = 3, roomId = 1111 },
New RoomEntity {role id = 4, roomId = 1111 },
New RoomEntity {role id = 1, roomId = 1111 },
New RoomEntity {role id = 6, roomId = 1111 },
New RoomEntity {role id = 1, roomId = 1111 },
New RoomEntity {role id = 5, roomId = 1111 },
New RoomEntity {role id = 8, roomId = 1111 },
New RoomEntity {role id = 7, roomId = 0 },
New RoomEntity {role id = 4, roomId = 1111 },
New RoomEntity {role id = 8, roomId = 1111 },
New RoomEntity {Region ID = 9, roomId = 1111 },
New RoomEntity {role id = 10, roomId = 0 },
New RoomEntity {role id = 10, roomId = 0}
};