Merge pull request #8595 from nopara73/1656676832

Bias random coin selection towards larger amounts
WalletWasabi · Jul 4, 2022 · d553c04 · d553c04
2 parents b3cba4f + 2e2b80a
commit d553c04
Showing 1 changed file with 15 additions and 2 deletions.
diff --git a/WalletWasabi/WabiSabi/Client/CoinJoinClient.cs b/WalletWasabi/WabiSabi/Client/CoinJoinClient.cs
@@ -576,9 +576,22 @@ internal static ImmutableList<SmartCoin> SelectCoinsForRound(IEnumerable<SmartCo
 		var remainingLargestAmounts = bestRepGroups
 			.Select(x => x.OrderByDescending(x => x.Amount).First())
 			.ToHashSet();
-		var largestAmount = remainingLargestAmounts.RandomElement();
+
+		// Select randomly at first just to have a starting value.
+		var selectedLargeCoin = remainingLargestAmounts.RandomElement();
+
+		// Bias selection towards larger numbers.
+		foreach (var coin in remainingLargestAmounts.OrderByDescending(x => x.Amount))
+		{
+			if (rnd.GetInt(1, 101) <= 50)
+			{
+				selectedLargeCoin = coin;
+				break;
+			}
+		}
+
 		var finalCandidate = bestRepGroups
-			.Where(x => x.OrderByDescending(x => x.Amount).First() == largestAmount)
+			.Where(x => x.OrderByDescending(x => x.Amount).First() == selectedLargeCoin)
 			.RandomElement();
 
 		return finalCandidate?.ToShuffled()?.ToImmutableList() ?? ImmutableList<SmartCoin>.Empty;