/// <summary>
/// RetrieveScoresAsync
/// </summary>
/// <param name="retrievalDetails"></param>
/// <returns></returns>
// [START FETCHSCORES_SERVER]
public async Task <IList <LeaderboardItemModel> > RetrieveScoresAsync(RetrieveScoresDetails retrievalDetails)
{
IDatabase db = _redis.GetDatabase();
List <LeaderboardItemModel> leaderboard = new List <LeaderboardItemModel>();
long offset = retrievalDetails.Offset;
long numScores = retrievalDetails.NumScores;
// If centered, get rank of specified user first
if (!string.IsNullOrWhiteSpace(retrievalDetails.CenterKey))
{
// SortedSetRankAsync corresponds to ZREVRANK
var rank = await db.SortedSetRankAsync(LEADERBOARD_KEY, retrievalDetails.CenterKey, Order.Descending);
// If specified user is not present, return empty leaderboard
if (!rank.HasValue)
{
return(leaderboard);
}
// Use rank to calculate offset
offset = Math.Max(0, rank.Value + retrievalDetails.Offset);
// Account for number of scores when we're attempting to center
// at element in rank [0, abs(offset))
if (offset <= 0)
{
numScores = rank.Value + Math.Abs((long)retrievalDetails.Offset) + 1;
}
}
// SortedSetRangeByScoreWithScoresAsync corresponds to ZREVRANGEBYSCORE [WITHSCORES]
var scores = await db.SortedSetRangeByScoreWithScoresAsync(LEADERBOARD_KEY,
skip : offset,
take : numScores,
order : Order.Descending);
var startingRank = offset;
for (int i = 0; i < scores.Length; i++)
{
var lbItem = new LeaderboardItemModel
{
Rank = startingRank++,
PlayerName = scores[i].Element.ToString(),
Score = scores[i].Score
};
leaderboard.Add(lbItem);
}
return(leaderboard);
}
public async Task <JsonResult> RetrieveScores(string centerKey, int offset, int numScores)
{
var retrievalDetails = new RetrieveScoresDetails
{
CenterKey = centerKey,
Offset = offset,
NumScores = numScores
};
var leaderboard = await _leaderboardRepo.RetrieveScoresAsync(retrievalDetails);
return(Json(leaderboard));
}
