source: binary-improvements/7dtd-server-fixes/src/PersistentData/Players.cs@ 455

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace AllocsFixes.PersistentData {
        [Serializable]
        public class Players {
                public readonly Dictionary<PlatformUserIdentifierAbs, Player> Dict = new Dictionary<PlatformUserIdentifierAbs, Player> ();

                public int Count => Dict.Count;

                public Player GetOrCreate (PlatformUserIdentifierAbs _internalId, PlatformUserIdentifierAbs _platformId, PlatformUserIdentifierAbs _crossPlatformId) {
                        if (_internalId == null) {
                                return null;
                        }

                        if (Dict.TryGetValue (_internalId, out Player pOld)) {
                                return pOld;
                        }

                        Log.Out ($"Created new player entry for ID: {_internalId}");
                        Player p = new Player (_internalId, _platformId, _crossPlatformId);
                        Dict.Add (_internalId, p);
                        return p;
                }

                public Player GetByInternalId (PlatformUserIdentifierAbs _internalId) {
                        if (_internalId == null) {
                                return null;
                        }

                        return Dict.TryGetValue (_internalId, out Player pOld) ? pOld : null;
                }

                public Player GetByUserId (PlatformUserIdentifierAbs _userId) {
                        foreach ((_, Player p) in Dict) {
                                if (p.PlatformId.Equals (_userId) || p.CrossPlatformId.Equals (_userId)) {
                                        return p;
                                }
                        }

                        return null;
                }

                public Player GetByString (string _nameOrId, bool _ignoreColorCodes) {
                        if (string.IsNullOrEmpty (_nameOrId)) {
                                return null;
                        }

                        if (PlatformUserIdentifierAbs.TryFromCombinedString (_nameOrId, out PlatformUserIdentifierAbs userId)) {
                                return GetByUserId (userId);
                        }

                        if (int.TryParse (_nameOrId, out int entityId)) {
                                foreach ((_, Player p) in Dict) {
                                        if (p.IsOnline && p.EntityID == entityId) {
                                                return p;
                                        }
                                }
                        }

                        foreach ((_, Player p) in Dict) {
                                string name = p.Name;
                                if (_ignoreColorCodes) {
                                        name = Regex.Replace (name, "\\[[0-9a-fA-F]{6}\\]", "");
                                }

                                if (p.IsOnline && name.EqualsCaseInsensitive (_nameOrId)) {
                                        return p;
                                }
                        }

                        return null;
                }
        }
}