refactor(exp/compute): Remove Topology interface

This change removes the Topology interface from the
`opendc-experiments-compute` module, which was meant for provisioning
the experimental topology. Howerver, with the stateless `HostSpec`
class, it is not needed to resolve the topology everytime.

3 files changed, 34 insertions, 41 deletions

diff --git a/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/CapelinRunner.kt b/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/CapelinRunner.kt
index e019af34..f1214b08 100644
--- a/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/CapelinRunner.kt
+++ b/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/CapelinRunner.kt
@@ -61,7 +61,7 @@ public class CapelinRunner(
         Provisioner(coroutineContext, clock, seed).use { provisioner ->
             provisioner.runSteps(
                 setupComputeService(serviceDomain, { createComputeScheduler(scenario.allocationPolicy, Random(it.seeder.nextLong())) }),
-                setupHosts(serviceDomain, topology.resolve(), optimize = true)
+                setupHosts(serviceDomain, topology, optimize = true)
             )
 
             if (outputPath != null) {
diff --git a/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/model/Topology.kt b/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/model/Topology.kt
index fe16a294..c90194ce 100644
--- a/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/model/Topology.kt
+++ b/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/model/Topology.kt
@@ -23,6 +23,6 @@
 package org.opendc.experiments.capelin.model
 
 /**
- * The topology topology on which we test the workload.
+ * The topology on which we simulate the workload.
  */
 public data class Topology(val name: String)
diff --git a/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/topology/TopologyFactories.kt b/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/topology/TopologyFactories.kt
index d152a6db..054adfcd 100644
--- a/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/topology/TopologyFactories.kt
+++ b/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/topology/TopologyFactories.kt
@@ -24,7 +24,6 @@
 package org.opendc.experiments.capelin.topology
 
 import org.opendc.experiments.compute.topology.HostSpec
-import org.opendc.experiments.compute.topology.Topology
 import org.opendc.simulator.compute.model.MachineModel
 import org.opendc.simulator.compute.model.MemoryUnit
 import org.opendc.simulator.compute.model.ProcessingNode
@@ -43,61 +42,55 @@ import kotlin.math.roundToLong
 private val reader = ClusterSpecReader()
 
 /**
- * Construct a [Topology] from the specified [file].
+ * Construct a topology from the specified [file].
  */
 fun clusterTopology(
     file: File,
     powerModel: PowerModel = LinearPowerModel(350.0, idlePower = 200.0),
     random: Random = Random(0)
-): Topology = clusterTopology(reader.read(file), powerModel, random)
+): List<HostSpec> {
+    return clusterTopology(reader.read(file), powerModel, random)
+}
 
 /**
- * Construct a [Topology] from the specified [input].
+ * Construct a topology from the specified [input].
  */
 fun clusterTopology(
     input: InputStream,
     powerModel: PowerModel = LinearPowerModel(350.0, idlePower = 200.0),
     random: Random = Random(0)
-): Topology = clusterTopology(reader.read(input), powerModel, random)
+): List<HostSpec> {
+    return clusterTopology(reader.read(input), powerModel, random)
+}
 
 /**
- * Construct a [Topology] from the given list of [clusters].
+ * Construct a topology from the given list of [clusters].
  */
-fun clusterTopology(
-    clusters: List<ClusterSpec>,
-    powerModel: PowerModel,
-    random: Random = Random(0)
-): Topology {
-    return object : Topology {
-        override fun resolve(): List<HostSpec> {
-            val hosts = mutableListOf<HostSpec>()
-            for (cluster in clusters) {
-                val cpuSpeed = cluster.cpuSpeed
-                val memoryPerHost = cluster.memCapacityPerHost.roundToLong()
-
-                val unknownProcessingNode = ProcessingNode("unknown", "unknown", "unknown", cluster.cpuCountPerHost)
-                val unknownMemoryUnit = MemoryUnit("unknown", "unknown", -1.0, memoryPerHost)
-                val machineModel = MachineModel(
-                    List(cluster.cpuCountPerHost) { coreId -> ProcessingUnit(unknownProcessingNode, coreId, cpuSpeed) },
-                    listOf(unknownMemoryUnit)
-                )
-
-                repeat(cluster.hostCount) {
-                    val spec = HostSpec(
-                        UUID(random.nextLong(), it.toLong()),
-                        "node-${cluster.name}-$it",
-                        mapOf("cluster" to cluster.id),
-                        machineModel,
-                        SimplePowerDriver(powerModel)
-                    )
+fun clusterTopology(clusters: List<ClusterSpec>, powerModel: PowerModel, random: Random = Random(0)): List<HostSpec> {
+    return clusters.flatMap { it.toHostSpecs(random, powerModel) }
+}
 
-                    hosts += spec
-                }
-            }
+/**
+ * Helper method to convert a [ClusterSpec] into a list of [HostSpec]s.
+ */
+private fun ClusterSpec.toHostSpecs(random: Random, powerModel: PowerModel): List<HostSpec> {
+    val cpuSpeed = cpuSpeed
+    val memoryPerHost = memCapacityPerHost.roundToLong()
 
-            return hosts
-        }
+    val unknownProcessingNode = ProcessingNode("unknown", "unknown", "unknown", cpuCountPerHost)
+    val unknownMemoryUnit = MemoryUnit("unknown", "unknown", -1.0, memoryPerHost)
+    val machineModel = MachineModel(
+        List(cpuCountPerHost) { coreId -> ProcessingUnit(unknownProcessingNode, coreId, cpuSpeed) },
+        listOf(unknownMemoryUnit)
+    )
 
-        override fun toString(): String = "ClusterSpecTopology"
+    return List(hostCount) {
+        HostSpec(
+            UUID(random.nextLong(), it.toLong()),
+            "node-$name-$it",
+            mapOf("cluster" to id),
+            machineModel,
+            SimplePowerDriver(powerModel)
+        )
     }
 }