From e9cad49d94b0b6d94ef9164096b12dcd0bf3c7bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?0hm=E2=98=98=EF=B8=8F?= <git8ankanroy@gmail.com>
Date: Fri, 26 Jun 2026 21:48:33 +0530
Subject: [PATCH] index serialized graph lookups

---
 lib/compat/loadSerializedHyperGraph.ts | 50 +++++++++++++-------------
 lib/core.ts                            | 14 ++++----
 2 files changed, 33 insertions(+), 31 deletions(-)

diff --git a/lib/compat/loadSerializedHyperGraph.ts b/lib/compat/loadSerializedHyperGraph.ts
index 6dc4eba..036f50f 100644
--- a/lib/compat/loadSerializedHyperGraph.ts
+++ b/lib/compat/loadSerializedHyperGraph.ts
@@ -312,20 +312,6 @@ const getCentermostPortIdForRegion = (
   return sortedPortIds[0]
 }
 
-const getSharedPortIdsForConnection = (
-  serializedHyperGraph: SerializedHyperGraph,
-  connection: NonNullable<SerializedHyperGraph["connections"]>[number],
-): string[] =>
-  serializedHyperGraph.ports
-    .filter(
-      (port) =>
-        (port.region1Id === connection.startRegionId &&
-          port.region2Id === connection.endRegionId) ||
-        (port.region2Id === connection.startRegionId &&
-          port.region1Id === connection.endRegionId),
-    )
-    .map((port) => port.portId)
-
 export const loadSerializedHyperGraph = (
   serializedHyperGraph: SerializedHyperGraph,
 ): {
@@ -335,8 +321,10 @@ export const loadSerializedHyperGraph = (
 } => {
   const filteredHyperGraph = filterObstacleRegions(serializedHyperGraph)
   const regionIdToIndex = new Map<string, number>()
+  const regionById = new Map<string, SerializedHyperGraph["regions"][number]>()
   const portIdToIndex = new Map<string, number>()
   const portById = new Map<string, SerializedHyperGraph["ports"][number]>()
+  const portIdsByRegionPair = new Map<string, string[]>()
   const solvedRouteByConnectionId = new Map(
     (filteredHyperGraph.solvedRoutes ?? []).map((route) => [
       route.connection.connectionId,
@@ -346,11 +334,23 @@ export const loadSerializedHyperGraph = (
 
   filteredHyperGraph.regions.forEach((region, regionIndex) => {
     regionIdToIndex.set(region.regionId, regionIndex)
+    regionById.set(region.regionId, region)
   })
 
   filteredHyperGraph.ports.forEach((port, portIndex) => {
     portIdToIndex.set(port.portId, portIndex)
     portById.set(port.portId, port)
+    const lesserRegionId =
+      port.region1Id < port.region2Id ? port.region1Id : port.region2Id
+    const greaterRegionId =
+      port.region1Id < port.region2Id ? port.region2Id : port.region1Id
+    const regionPairKey = `${lesserRegionId}\0${greaterRegionId}`
+    const portIds = portIdsByRegionPair.get(regionPairKey)
+    if (portIds) {
+      portIds.push(port.portId)
+    } else {
+      portIdsByRegionPair.set(regionPairKey, [port.portId])
+    }
   })
 
   const regionCount = filteredHyperGraph.regions.length
@@ -485,10 +485,16 @@ export const loadSerializedHyperGraph = (
   const routableConnections = connections
     .map((connection) => {
       const solvedRoute = solvedRouteByConnectionId.get(connection.connectionId)
-      const sharedPortIds = getSharedPortIdsForConnection(
-        filteredHyperGraph,
-        connection,
-      )
+      const lesserRegionId =
+        connection.startRegionId < connection.endRegionId
+          ? connection.startRegionId
+          : connection.endRegionId
+      const greaterRegionId =
+        connection.startRegionId < connection.endRegionId
+          ? connection.endRegionId
+          : connection.startRegionId
+      const sharedPortIds =
+        portIdsByRegionPair.get(`${lesserRegionId}\0${greaterRegionId}`) ?? []
 
       return {
         connection,
@@ -509,15 +515,11 @@ export const loadSerializedHyperGraph = (
 
   routableConnections.forEach(({ connection, solvedRoute }, routeIndex) => {
     const fallbackStartPortId = getCentermostPortIdForRegion(
-      filteredHyperGraph.regions.find(
-        (region) => region.regionId === connection.startRegionId,
-      ),
+      regionById.get(connection.startRegionId),
       portById,
     )
     const fallbackEndPortId = getCentermostPortIdForRegion(
-      filteredHyperGraph.regions.find(
-        (region) => region.regionId === connection.endRegionId,
-      ),
+      regionById.get(connection.endRegionId),
       portById,
     )
 
diff --git a/lib/core.ts b/lib/core.ts
index d334dc5..216f65d 100644
--- a/lib/core.ts
+++ b/lib/core.ts
@@ -566,10 +566,6 @@ export class TinyHyperGraphSolver extends BaseSolver {
       if (neighborPortId === currentCandidate.portId) continue
       if (problem.portSectionMask[neighborPortId] === 0) continue
 
-      const g = this.computeG(currentCandidate, neighborPortId)
-      if (!Number.isFinite(g)) continue
-      const h = this.computeH(neighborPortId)
-
       const nextRegionId =
         topology.incidentPortRegion[neighborPortId][0] ===
         currentCandidate.nextRegionId
@@ -583,6 +579,13 @@ export class TinyHyperGraphSolver extends BaseSolver {
         continue
       }
 
+      const g = this.computeG(currentCandidate, neighborPortId)
+      if (!Number.isFinite(g)) continue
+
+      const candidateHopId = this.getHopId(neighborPortId, nextRegionId)
+      if (g >= this.getCandidateBestCost(candidateHopId)) continue
+
+      const h = this.computeH(neighborPortId)
       const newCandidate = {
         prevRegionId: currentCandidate.nextRegionId,
         nextRegionId,
@@ -598,9 +601,6 @@ export class TinyHyperGraphSolver extends BaseSolver {
         return
       }
 
-      const candidateHopId = this.getHopId(neighborPortId, nextRegionId)
-      if (g >= this.getCandidateBestCost(candidateHopId)) continue
-
       this.setCandidateBestCost(candidateHopId, g)
       state.candidateQueue.queue(newCandidate)
     }