1 files changed, 46 insertions, 0 deletions
diff --git a/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/zone/UpgradePolicy.java b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/zone/UpgradePolicy.java
new file mode 100644
index 00000000000..96ff468d2d6
--- /dev/null
+++ b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/zone/UpgradePolicy.java
@@ -0,0 +1,46 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.hosted.controller.api.integration.zone;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * This class declares the order to use when upgrading zones in a system.
+ *
+ * @author mpolden
+ */
+public class UpgradePolicy {
+
+    private final List<List<ZoneId>> zones;
+
+    private UpgradePolicy(List<List<ZoneId>> zones) {
+        this.zones = zones;
+    }
+
+    public List<List<ZoneId>> asList() {
+        return Collections.unmodifiableList(zones);
+    }
+
+    private UpgradePolicy with(ZoneId... zone) {
+        List<List<ZoneId>> zones = new ArrayList<>(this.zones);
+        zones.add(Arrays.asList(zone));
+        return new UpgradePolicy(zones);
+    }
+
+    /** Upgrade given zone as the next step */
+    public UpgradePolicy upgrade(ZoneId zone) {
+        return with(zone);
+    }
+
+    /** Upgrade given zones in parallel as the next step */
+    public UpgradePolicy upgradeInParallel(ZoneId... zone) {
+        return with(zone);
+    }
+
+    public static UpgradePolicy create() {
+        return new UpgradePolicy(Collections.emptyList());
+    }
+
+}