69 lines
2.2 KiB
C#
69 lines
2.2 KiB
C#
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using System.Numerics;
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using Utils;
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using YamlDotNet.Core.Tokens;
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namespace CodexPlugin.OverwatchSupport
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{
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public class KademliaPositionFinder
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{
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public CodexNodeIdentity[] DeterminePositions(CodexNodeIdentity[] identities)
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{
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var zero = identities.First();
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var distances = CalculateDistances(zero, identities);
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var maxDistance = distances.Values.Max();
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CalculateNormalizedPositions(distances, maxDistance);
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return identities;
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}
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private Dictionary<CodexNodeIdentity, BigInteger> CalculateDistances(CodexNodeIdentity zero, CodexNodeIdentity[] identities)
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{
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var result = new Dictionary<CodexNodeIdentity, BigInteger>();
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foreach (var id in identities.Skip(1))
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{
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result.Add(id, GetDistance(zero.NodeId, id.NodeId));
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}
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return result;
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}
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private BigInteger GetDistance(string id1, string id2)
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{
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var one = BigInteger.Parse(id1, System.Globalization.NumberStyles.HexNumber).ToByteArray();
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var two = BigInteger.Parse(id2, System.Globalization.NumberStyles.HexNumber).ToByteArray();
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var x = Xor(one, two);
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return new BigInteger(x, isUnsigned: true);
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}
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private byte[] Xor(byte[] one, byte[] two)
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{
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if (one.Length != two.Length) throw new Exception("Not equal length");
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var result = new byte[one.Length];
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for (int i = 0; i < one.Length; i++)
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{
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uint a = one[i];
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uint b = two[i];
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uint c = (a ^ b);
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result[i] = (byte)c;
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}
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return result;
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}
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private void CalculateNormalizedPositions(Dictionary<CodexNodeIdentity, BigInteger> distances, BigInteger maxDistance)
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{
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foreach (var pair in distances)
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{
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pair.Key.KademliaNormalizedPosition = DeterminePosition(pair.Value, maxDistance);
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}
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}
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private float DeterminePosition(BigInteger value, BigInteger maxDistance)
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{
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var f = (value * 10000) / maxDistance;
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return ((float)f) / 10000.0f;
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}
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}
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}
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