Merge branch 'master' into gossip-gc

1 files changed, 156 insertions, 0 deletions

diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/HierarchyConfig.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/HierarchyConfig.java
new file mode 100644
index 0000000..dc5241d
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/HierarchyConfig.java
@@ -0,0 +1,156 @@
+package pl.edu.mimuw.cloudatlas.agent;
+
+import pl.edu.mimuw.cloudatlas.agent.messages.*;
+import pl.edu.mimuw.cloudatlas.agent.modules.GossipGirlStrategies;
+import pl.edu.mimuw.cloudatlas.agent.modules.TimerScheduledTask;
+import pl.edu.mimuw.cloudatlas.model.*;
+
+import java.lang.reflect.UndeclaredThrowableException;
+import java.util.*;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Supplier;
+
+public class HierarchyConfig {
+    private GossipGirlStrategies gossipGirlStrategies;
+    private GossipGirlStrategies.ZoneSelectionStrategy zoneSelectionStrategy;
+    private Random random = new Random();
+    private EventBus eventBus;
+
+    HierarchyConfig(EventBus eventBus, String zonePath, String zoneStrategy) {
+        zoneSelectionStrategy = parseStrategy(zoneStrategy);
+        gossipGirlStrategies = new GossipGirlStrategies(new PathName(zonePath));
+        this.eventBus = eventBus;
+    }
+
+    private GossipGirlStrategies.ZoneSelectionStrategy parseStrategy(String selectionStrategy) {
+        switch (selectionStrategy) {
+            case "RoundRobinExp":
+                return GossipGirlStrategies.ZoneSelectionStrategy.ROUND_ROBIN_EXP_FREQ;
+            case "RoundRobinUniform":
+                return GossipGirlStrategies.ZoneSelectionStrategy.ROUND_ROBIN_SAME_FREQ;
+            case "RandomExp":
+                return GossipGirlStrategies.ZoneSelectionStrategy.RANDOM_DECR_EXP;
+            case "RandomUniform":
+                return GossipGirlStrategies.ZoneSelectionStrategy.RANDOM_UNFIORM;
+            default:
+                throw new UnsupportedOperationException("Selection strategy doesnt exist");
+        }
+    }
+
+    public void startGossip(long gossipPeriod) {
+        Supplier<TimerScheduledTask> taskSupplier = () ->
+                new TimerScheduledTask() {
+                    public void run() {
+                        try {
+                            System.out.println("INFO: initiating gossip");
+                            PathName gossipLevel = gossipGirlStrategies.selectStrategy(zoneSelectionStrategy);
+                            ValueContact contact = selectContactFromLevel(gossipLevel);
+                            if (contact != null) {
+                                System.out.println("INFO: found a contact " + contact.toString());
+                                InitiateGossipMessage message = new InitiateGossipMessage("", 0, new PathName("/uw/violet07"), contact);
+                                sendMessage(message);
+                            } else {
+                                System.out.println("DEBUG: couldn't find contact for gossip");
+                            }
+                        } catch (InterruptedException e) {
+                            System.out.println("Interrupted while initiating gossip");
+                        } catch (Exception e) {
+                            System.out.println("ERROR: something happened " + e.toString());
+                        }
+                    }
+                };
+
+        AgentUtils.startRecursiveTask(taskSupplier, gossipPeriod, eventBus);
+    }
+
+    private ValueContact selectContactFromLevel(PathName path) throws Exception {
+        CompletableFuture<ResponseMessage> responseFuture = new CompletableFuture();
+        this.eventBus.addMessage(new RequestStateMessage("", 0, responseFuture));
+        StateMessage response = (StateMessage) responseFuture.get();
+        ZMI root = response.getZMI();
+        List<ZMI> siblings = getSiblings(root, path);
+        filterEmptyContacts(siblings);
+        if (siblings.isEmpty()) {
+            return selectFallbackContact(response.getContacts());
+        }
+        ZMI zmi = selectZMI(siblings);
+        ValueSet contactsValue = (ValueSet) zmi.getAttributes().getOrNull("contacts");
+        Set<Value> valueSet = contactsValue.getValue();
+        return selectContactFromSet(valueSet);
+    }
+
+    // TODO
+    private ValueContact selectFallbackContact(Set<ValueContact> contacts) throws Exception {
+        if (contacts.isEmpty()) {
+            return null;
+        } else {
+            return selectContactFromSet(contacts);
+        }
+    }
+
+    private ZMI selectZMI(List<ZMI> zmis) throws Exception {
+        int i = random.nextInt(zmis.size());
+        for (ZMI zmi : zmis) {
+            if (i == 0) {
+                return zmi;
+            }
+            i--;
+        }
+        System.out.println("ERROR: empty list passed to selectZMI");
+        throw new Exception("empty list passed to selectZMI");
+    }
+
+    private <T> ValueContact selectContactFromSet(Set<T> contacts) throws Exception {
+        int i = random.nextInt(contacts.size());
+        for (T contact : contacts) {
+            if (i == 0) {
+                return (ValueContact) contact;
+            }
+            i--;
+        }
+        System.out.println("ERROR: empty list passed to selectContactFromSet");
+        throw new Exception("empty list passed to selectContactFromSet");
+    }
+
+    private List<ZMI> getSiblings(ZMI root, PathName path) {
+        try {
+            List<ZMI> siblingsAndI = root.findDescendant(path).getFather().getSons();
+            List<ZMI> siblings = new ArrayList();
+            for (ZMI siblingOrI : siblingsAndI) {
+                if (!siblingOrI.getPathName().equals(path)) {
+                    siblings.add(siblingOrI);
+                }
+            }
+            return siblings;
+        } catch (ZMI.NoSuchZoneException e) {
+            System.out.println("ERROR: didn't find path when looking for siblings");
+            return new ArrayList();
+        }
+    }
+
+    private void filterEmptyContacts(List<ZMI> zmis) {
+        Iterator<ZMI> iterator = zmis.iterator();
+        while (iterator.hasNext()) {
+            ZMI zmi = iterator.next();
+            ValueSet contacts = (ValueSet) zmi.getAttributes().getOrNull("contacts");
+            if (contacts == null || contacts.isNull() || contacts.isEmpty()) {
+                iterator.remove();
+            }
+        }
+    }
+
+    public void startQueries(long queriesPeriod) {
+        Supplier<TimerScheduledTask> taskSupplier = () ->
+                new TimerScheduledTask() {
+                    public void run() {
+                        try {
+                            sendMessage(new RunQueriesMessage("", 0));
+                        } catch (InterruptedException e) {
+                            System.out.println("Interrupted while triggering queries");
+                        }
+                    }
+                };
+
+        AgentUtils.startRecursiveTask(taskSupplier, queriesPeriod, eventBus);
+    }
+}