1 files changed, 57 insertions, 0 deletions
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/PerformanceInterferenceModel.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/PerformanceInterferenceModel.kt
new file mode 100644
index 00000000..5e0928b7
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/PerformanceInterferenceModel.kt
@@ -0,0 +1,57 @@
+package com.atlarge.opendc.core.workload
+
+import com.atlarge.opendc.core.resource.Resource
+import java.util.UUID
+
+/**
+ * Meta-data key for the [PerformanceInterferenceModel] of an image.
+ */
+const val IMAGE_PERF_INTERFERENCE_MODEL = "image:performance-interference"
+
+/**
+ * Performance Interference Model describing the variability incurred by different sets of workloads if colocated.
+ *
+ * @param items The [PerformanceInterferenceModelItem]s that make up this model.
+ */
+data class PerformanceInterferenceModel(
+    val items: Set<PerformanceInterferenceModelItem>
+) {
+    fun apply(colocatedWorkloads: Set<Resource>): Double {
+        val colocatedWorkloadIds = colocatedWorkloads.map { it.uid }
+        val intersectingItems = items.filter { item ->
+            colocatedWorkloadIds.intersect(item.workloadIds).size > 1
+        }
+
+        if (intersectingItems.isEmpty()) {
+            return 1.0
+        }
+        return intersectingItems.map { it.performanceScore }.min() ?: error("Minimum score must exist.")
+    }
+}
+
+/**
+ * Model describing how a specific set of workloads causes performance variability for each workload.
+ *
+ * @param workloadIds The IDs of the workloads that together cause performance variability for each workload in the set.
+ * @param performanceScore The performance score that should be applied to each workload's performance. 1 means no
+ * influence, <1 means that performance degrades, and >1 means that performance improves.
+ */
+data class PerformanceInterferenceModelItem(
+    val workloadIds: Set<UUID>,
+    val performanceScore: Double
+) {
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as PerformanceInterferenceModelItem
+
+        if (workloadIds != other.workloadIds) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        return workloadIds.hashCode()
+    }
+}