source: binary-improvements/7dtd-server-fixes/src/LandClaimList.cs@ 256

using System;
using System.Collections.Generic;

using AllocsFixes.PersistentData;

namespace AllocsFixes
{
        public class LandClaimList {
                public delegate bool OwnerFilter (Player owner);

                public delegate bool PositionFilter (Vector3i position);

                public static Dictionary<Player, List<Vector3i>> GetLandClaims (OwnerFilter[] _ownerFilters, PositionFilter[] _positionFilters) {
                        Dictionary<Vector3i, PersistentPlayerData> d = GameManager.Instance.GetPersistentPlayerList ().m_lpBlockMap;
                        Dictionary<Player, List<Vector3i>> result = new Dictionary<Player, List<Vector3i>> ();

                        if (d != null) {
                                Dictionary<PersistentPlayerData, List<Vector3i>> owners = new Dictionary<PersistentPlayerData, List<Vector3i>> ();
                                foreach (KeyValuePair<Vector3i, PersistentPlayerData> kvp in d) {
                                        bool allowed = true;
                                        if (_positionFilters != null) {
                                                foreach (PositionFilter pf in _positionFilters) {
                                                        if (!pf (kvp.Key)) {
                                                                allowed = false;
                                                                break;
                                                        }
                                                }
                                        }
                                        if (allowed) {
                                                if (!owners.ContainsKey (kvp.Value)) {
                                                        owners.Add (kvp.Value, new List<Vector3i> ());
                                                }
                                                owners [kvp.Value].Add (kvp.Key);
                                        }
                                }

                                foreach (KeyValuePair<PersistentPlayerData, List<Vector3i>> kvp in owners) {
                                        Player p = PersistentData.PersistentContainer.Instance.Players [kvp.Key.PlayerId, false];
                                        if (p == null) {
                                                p = new Player (kvp.Key.PlayerId);
                                        }

                                        bool allowed = true;
                                        if (_ownerFilters != null) {
                                                foreach (OwnerFilter of in _ownerFilters) {
                                                        if (!of (p)) {
                                                                allowed = false;
                                                                break;
                                                        }
                                                }
                                        }

                                        if (allowed) {
                                                result.Add (p, new List<Vector3i> ());
                                                foreach (Vector3i v in kvp.Value) {
                                                        result [p].Add (v);
                                                }
                                        }
                                }
                        }
                        return result;
                }

                public static OwnerFilter SteamIdFilter (string _steamId) {
                        return p => p.SteamID.Equals (_steamId);
                }

                public static PositionFilter CloseToFilter2dRect (Vector3i _position, int _maxDistance) {
                        return v => Math.Abs (v.x - _position.x) <= _maxDistance && Math.Abs (v.z - _position.z) <= _maxDistance;
                }

                public static OwnerFilter OrOwnerFilter (OwnerFilter _f1, OwnerFilter _f2) {
                        return p => _f1 (p) || _f2 (p);
                }

        }
}