core: stdcm: limit the loop where we look for possible delays

We would keep looking for different "openings" even very far in the future. This limits both conflict detection calls and the early steps of edge building. Signed-off-by: Eloi Charpentier <[email protected]>
OpenRailAssociation · Dec 19, 2024 · 8a3622d · 8a3622d
1 parent 5d127e0
commit 8a3622d
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Showing 4 changed files with 26 additions and 3 deletions.
diff --git a/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/DelayManager.kt b/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/DelayManager.kt
@@ -9,6 +9,8 @@ import fr.sncf.osrd.utils.units.Distance.Companion.fromMeters
 import fr.sncf.osrd.utils.units.Offset
 import fr.sncf.osrd.utils.units.meters
 import java.util.*
+import kotlin.math.max
+import kotlin.math.min
 
 /**
  * This class contains all the methods used to handle delays (how much we can add, how much we need
@@ -29,14 +31,17 @@ internal constructor(
      */
     fun minimumDelaysPerOpening(
         infraExplorerWithNewEnvelope: InfraExplorerWithEnvelope,
-        startTime: Double,
+        timeData: TimeData,
         envelope: Envelope,
         startOffset: Offset<Block>,
     ): NavigableSet<Double> {
+        val startTime = timeData.earliestReachableTime
+        val maximumDelay = computeMaximumDelay(timeData)
         val res = TreeSet<Double>()
         val endOffset = startOffset + fromMeters(envelope.endPos)
         var time = startTime
         while (java.lang.Double.isFinite(time)) {
+            if (time - startTime > maximumDelay) break
             val availability =
                 getLastBlockAvailability(
                     infraExplorerWithNewEnvelope,
@@ -58,6 +63,19 @@ internal constructor(
         return res
     }
 
+    /**
+     * Compute how much delay we may add here. Prevents the generation of edges very far in the
+     * future that would necessarily be discarded.
+     */
+    private fun computeMaximumDelay(data: TimeData): Double {
+        val maxExtraRunTime = maxRunTime - data.totalRunningTime
+        val maxDelayForMaxRunTime = data.maxDepartureDelayingWithoutConflict + maxExtraRunTime
+        val maxDelayWithLocalConflict =
+            data.maxDepartureDelayingWithoutConflict + data.timeOfNextConflictAtLocation -
+                data.earliestReachableTime
+        return max(0.0, min(maxDelayForMaxRunTime, maxDelayWithLocalConflict))
+    }
+
     /** Returns the start time of the next occupancy for the block */
     fun findNextOccupancy(
         infraExplorer: InfraExplorerWithEnvelope,

diff --git a/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/STDCMEdgeBuilder.kt b/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/STDCMEdgeBuilder.kt
@@ -132,7 +132,7 @@ internal constructor(
     private fun getDelaysPerOpening(): Set<Double> {
         return graph.delayManager.minimumDelaysPerOpening(
             getExplorerWithNewEnvelope()!!,
-            prevNode.timeData.earliestReachableTime,
+            prevNode.timeData,
             envelope!!,
             startOffset,
         )

diff --git a/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/STDCMPathfinding.kt b/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/STDCMPathfinding.kt
@@ -25,6 +25,7 @@ import io.opentelemetry.instrumentation.annotations.WithSpan
 import java.time.Duration
 import java.time.Instant
 import java.util.*
+import kotlin.Double.Companion.POSITIVE_INFINITY
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
 
@@ -272,7 +273,7 @@ class STDCMPathfinding(
                             earliestReachableTime = startTime,
                             maxDepartureDelayingWithoutConflict = maxDepartureDelay,
                             departureTime = startTime,
-                            timeOfNextConflictAtLocation = 0.0,
+                            timeOfNextConflictAtLocation = POSITIVE_INFINITY,
                             totalRunningTime = 0.0,
                             stopTimeData = listOf(),
                             maxFirstDepartureDelaying = maxDepartureDelay,

diff --git a/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/TimeData.kt b/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/TimeData.kt
@@ -89,6 +89,9 @@ data class TimeData(
         var maxDepartureDelayingWithoutConflict = maxDepartureDelayingWithoutConflict
         val nextEarliestReachableTime =
             earliestReachableTime + extraTravelTime + (extraStopTime ?: 0.0)
+        var timeOfNextConflict = timeOfNextConflictAtLocation
+        if (maxAdditionalStopTime != null)
+            timeOfNextConflict = nextEarliestReachableTime + maxAdditionalStopTime
         if (extraStopTime != null) {
             val stopDataCopy = newStopData.toMutableList()
             stopDataCopy.add(
@@ -108,6 +111,7 @@ data class TimeData(
             maxDepartureDelayingWithoutConflict = maxDepartureDelayingWithoutConflict,
             maxFirstDepartureDelaying =
                 min(maxFirstDepartureDelaying, (maxAdditionalStopTime ?: POSITIVE_INFINITY)),
+            timeOfNextConflictAtLocation = timeOfNextConflict,
         )
     }