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⚡ Bolt: Avoid redundant O(N) ToDictionary allocation in AddReachabilityWarnings hot path #291

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⚡ Bolt: Avoid redundant O(N) ToDictionary allocation in AddReachabilityWarnings hot path #291

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9 changes: 6 additions & 3 deletions src/MedWNetworkSim.App/Services/NetworkSimulationEngine.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -204,10 +204,13 @@ private static void AddReachabilityWarnings(NetworkModel network, RoutingTraffic
var adjacency = BuildAdjacency(network);
var permissionResolver = new EdgeTrafficPermissionResolver();

// Bolt: Extract ToDictionary to avoid O(N) allocation inside the double loop (O(P*C)) of producer/consumer checks
var edgesById = network.Edges.ToDictionary(edge => edge.Id, Comparer);

foreach (var producerNodeId in producers)
{
var hasReachableConsumer = consumers.Any(consumerNodeId =>
HasPermittedPath(network, context, adjacency, permissionResolver, producerNodeId, consumerNodeId));
HasPermittedPath(network, context, adjacency, edgesById, permissionResolver, producerNodeId, consumerNodeId));
if (!hasReachableConsumer)
{
context.Notes.Add(
Expand All @@ -218,7 +221,7 @@ private static void AddReachabilityWarnings(NetworkModel network, RoutingTraffic
foreach (var consumerNodeId in consumers)
{
var hasReachableProducer = producers.Any(producerNodeId =>
HasPermittedPath(network, context, adjacency, permissionResolver, producerNodeId, consumerNodeId));
HasPermittedPath(network, context, adjacency, edgesById, permissionResolver, producerNodeId, consumerNodeId));
if (!hasReachableProducer)
{
context.Notes.Add(
Expand All @@ -231,6 +234,7 @@ private static bool HasPermittedPath(
NetworkModel network,
RoutingTrafficContext context,
IReadOnlyDictionary<string, List<GraphArc>> adjacency,
IReadOnlyDictionary<string, EdgeModel> edgesById,
EdgeTrafficPermissionResolver permissionResolver,
string producerNodeId,
string consumerNodeId)
Expand All @@ -240,7 +244,6 @@ private static bool HasPermittedPath(
return true;
}

var edgesById = network.Edges.ToDictionary(edge => edge.Id, Comparer);
var queue = new Queue<string>();
var visited = new HashSet<string>(Comparer) { producerNodeId };
queue.Enqueue(producerNodeId);
Expand Down