Merge pull request #77 from m-chrzan/stanik

Stanik

12 files changed, 585 insertions, 1 deletions

diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/GetStateMessage.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/GetStateMessage.java
new file mode 100644
index 0000000..63392e8
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/GetStateMessage.java
@@ -0,0 +1,22 @@
+package pl.edu.mimuw.cloudatlas.agent.messages;
+
+import pl.edu.mimuw.cloudatlas.agent.modules.ModuleType;
+
+public class GetStateMessage extends StanikMessage {
+    private ModuleType requestingModule;
+    private long requestId;
+
+    public GetStateMessage(String messageId, long timestamp, ModuleType requestingModule, long requestId) {
+        super(messageId, timestamp, Type.GET_STATE);
+        this.requestingModule = requestingModule;
+        this.requestId = requestId;
+    }
+
+    public ModuleType getRequestingModule() {
+        return requestingModule;
+    }
+
+    public long getRequestId() {
+        return requestId;
+    }
+}
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/ResponseMessage.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/ResponseMessage.java
new file mode 100644
index 0000000..02b3337
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/ResponseMessage.java
@@ -0,0 +1,31 @@
+package pl.edu.mimuw.cloudatlas.agent.messages;
+
+import pl.edu.mimuw.cloudatlas.agent.modules.Module;
+import pl.edu.mimuw.cloudatlas.agent.modules.ModuleType;
+
+public abstract class ResponseMessage extends AgentMessage {
+    public enum Type {
+        STATE
+    }
+
+    Type type;
+    long requestId;
+
+    public ResponseMessage(String messageId, ModuleType destinationModule, long timestamp, Type type, long requestId) {
+        super(messageId, destinationModule, timestamp);
+        this.type = type;
+        this.requestId = requestId;
+    }
+
+    public void callMe(Module module) throws InterruptedException, Module.InvalidMessageType {
+        module.handleTyped(this);
+    }
+
+    public long getRequestId() {
+        return requestId;
+    }
+
+    public Type getType() {
+        return type;
+    }
+}
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/StanikMessage.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/StanikMessage.java
new file mode 100644
index 0000000..b23f6e0
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/StanikMessage.java
@@ -0,0 +1,27 @@
+package pl.edu.mimuw.cloudatlas.agent.messages;
+
+import pl.edu.mimuw.cloudatlas.agent.modules.Module;
+import pl.edu.mimuw.cloudatlas.agent.modules.ModuleType;
+
+public abstract class StanikMessage extends AgentMessage {
+    public enum Type {
+        GET_STATE,
+        UPDATE_ATTRIBUTES,
+        UPDATE_QUERIES
+    }
+
+    private Type type;
+
+    public StanikMessage(String messageId, long timestamp, Type type) {
+        super(messageId, ModuleType.STATE, timestamp);
+        this.type = type;
+    }
+
+    public Type getType() {
+        return type;
+    }
+
+    public void callMe(Module module) throws InterruptedException, Module.InvalidMessageType {
+        module.handleTyped(this);
+    }
+}
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/StateMessage.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/StateMessage.java
new file mode 100644
index 0000000..f7f490b
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/StateMessage.java
@@ -0,0 +1,29 @@
+package pl.edu.mimuw.cloudatlas.agent.messages;
+
+import java.util.Map;
+import java.util.Map.Entry;
+
+import pl.edu.mimuw.cloudatlas.agent.modules.ModuleType;
+import pl.edu.mimuw.cloudatlas.model.Attribute;
+import pl.edu.mimuw.cloudatlas.model.ValueQuery;
+import pl.edu.mimuw.cloudatlas.model.ValueTime;
+import pl.edu.mimuw.cloudatlas.model.ZMI;
+
+public class StateMessage extends ResponseMessage {
+    private ZMI zmi;
+    private Map<Attribute, Entry<ValueQuery, ValueTime>> queries;
+
+    public StateMessage(String messageId, ModuleType destinationModule, long timestamp, long requestId, ZMI zmi, Map<Attribute, Entry<ValueQuery, ValueTime>> queries) {
+        super(messageId, destinationModule, timestamp, Type.STATE, requestId);
+        this.zmi = zmi;
+        this.queries = queries;
+    }
+
+    public ZMI getZMI() {
+        return zmi;
+    }
+
+    public Map<Attribute, Entry<ValueQuery, ValueTime>> getQueries() {
+        return queries;
+    }
+}
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/UpdateAttributesMessage.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/UpdateAttributesMessage.java
new file mode 100644
index 0000000..7e41631
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/UpdateAttributesMessage.java
@@ -0,0 +1,23 @@
+package pl.edu.mimuw.cloudatlas.agent.messages;
+
+import pl.edu.mimuw.cloudatlas.agent.modules.ModuleType;
+import pl.edu.mimuw.cloudatlas.model.AttributesMap;
+
+public class UpdateAttributesMessage extends StanikMessage {
+    private String pathName;
+    private AttributesMap attributes;
+
+    public UpdateAttributesMessage(String messageId, long timestamp, String pathName, AttributesMap attributes) {
+        super(messageId, timestamp, Type.UPDATE_ATTRIBUTES);
+        this.pathName = pathName;
+        this.attributes = attributes;
+    }
+
+    public String getPathName() {
+        return pathName;
+    }
+
+    public AttributesMap getAttributes() {
+        return attributes;
+    }
+}
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/UpdateQueriesMessage.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/UpdateQueriesMessage.java
new file mode 100644
index 0000000..58ad55a
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/messages/UpdateQueriesMessage.java
@@ -0,0 +1,21 @@
+package pl.edu.mimuw.cloudatlas.agent.messages;
+
+import java.util.Map;
+import java.util.Map.Entry;
+
+import pl.edu.mimuw.cloudatlas.model.Attribute;
+import pl.edu.mimuw.cloudatlas.model.ValueQuery;
+import pl.edu.mimuw.cloudatlas.model.ValueTime;
+
+public class UpdateQueriesMessage extends StanikMessage {
+    private Map<Attribute, Entry<ValueQuery, ValueTime>> queries;
+
+    public UpdateQueriesMessage(String messageId, long timestamp, Map<Attribute, Entry<ValueQuery, ValueTime>> queries) {
+        super(messageId, timestamp, Type.UPDATE_QUERIES);
+        this.queries = queries;
+    }
+
+    public Map<Attribute, Entry<ValueQuery, ValueTime>> getQueries() {
+        return queries;
+    }
+}
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Module.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Module.java
index a50a95f..d0bf083 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Module.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Module.java
@@ -3,7 +3,9 @@ package pl.edu.mimuw.cloudatlas.agent.modules;
 import pl.edu.mimuw.cloudatlas.agent.Executor;
 import pl.edu.mimuw.cloudatlas.agent.messages.AgentMessage;
 import pl.edu.mimuw.cloudatlas.agent.messages.TimerSchedulerMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.ResponseMessage;
 import pl.edu.mimuw.cloudatlas.agent.messages.RMIMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.StanikMessage;
 
 /*
  * A Module is a (potentially stateful) event handler.
@@ -34,6 +36,14 @@ public abstract class Module {
         throw new InvalidMessageType("Got an RMIMessage in module " + moduleType.toString());
     }
 
+    public void handleTyped(StanikMessage message) throws InterruptedException, InvalidMessageType {
+        throw new InvalidMessageType("Got a StanikMessage in module " + moduleType.toString());
+    }
+
+    public void handleTyped(ResponseMessage message) throws InterruptedException, InvalidMessageType {
+        throw new InvalidMessageType("Got a ResponseMessage in module " + moduleType.toString());
+    }
+
     public void setExecutor(Executor executor) {
         this.executor = executor;
     }
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/ModuleType.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/ModuleType.java
index ff4a92e..d221f06 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/ModuleType.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/ModuleType.java
@@ -8,5 +8,7 @@ public enum ModuleType {
     GOSSIP_IN,
     GOSSIP_OUT,
     STATE,
-    QUERY
+    QUERY,
+    // for testing
+    TEST
 }
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Stanik.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Stanik.java
new file mode 100644
index 0000000..e8721b3
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Stanik.java
@@ -0,0 +1,167 @@
+package pl.edu.mimuw.cloudatlas.agent.modules;
+
+import java.util.Iterator;
+import java.util.HashMap;
+import java.util.Map.Entry;
+
+import pl.edu.mimuw.cloudatlas.agent.messages.AgentMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.GetStateMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.StateMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.StanikMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.UpdateAttributesMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.UpdateQueriesMessage;
+import pl.edu.mimuw.cloudatlas.model.Attribute;
+import pl.edu.mimuw.cloudatlas.model.AttributesMap;
+import pl.edu.mimuw.cloudatlas.model.PathName;
+import pl.edu.mimuw.cloudatlas.model.Type;
+import pl.edu.mimuw.cloudatlas.model.TypePrimitive;
+import pl.edu.mimuw.cloudatlas.model.Value;
+import pl.edu.mimuw.cloudatlas.model.ValueBoolean;
+import pl.edu.mimuw.cloudatlas.model.ValueQuery;
+import pl.edu.mimuw.cloudatlas.model.ValueString;
+import pl.edu.mimuw.cloudatlas.model.ValueTime;
+import pl.edu.mimuw.cloudatlas.model.ZMI;
+
+public class Stanik extends Module {
+    private class InvalidUpdateAttributesMessage extends Exception {
+        public InvalidUpdateAttributesMessage(String message) {
+            super(message);
+        }
+    }
+
+    private ZMI hierarchy;
+    private HashMap<Attribute, Entry<ValueQuery, ValueTime>> queries;
+
+    public Stanik() {
+        super(ModuleType.STATE);
+        hierarchy = new ZMI();
+        queries = new HashMap<Attribute, Entry<ValueQuery, ValueTime>>();
+        hierarchy.getAttributes().add("timestamp", new ValueTime(0l));
+    }
+
+    public void handleTyped(StanikMessage message) throws InterruptedException, InvalidMessageType {
+        switch(message.getType()) {
+            case GET_STATE:
+                handleGetState((GetStateMessage) message);
+                break;
+            case UPDATE_ATTRIBUTES:
+                handleUpdateAttributes((UpdateAttributesMessage) message);
+                break;
+            case UPDATE_QUERIES:
+                handleUpdateQueries((UpdateQueriesMessage) message);
+                break;
+            default:
+                throw new InvalidMessageType("This type of message cannot be handled by Stanik");
+        }
+    }
+
+    public void handleGetState(GetStateMessage message) throws InterruptedException {
+        StateMessage response = new StateMessage("", message.getRequestingModule(), 0, message.getRequestId(), hierarchy.clone(), (HashMap<Attribute, Entry<ValueQuery, ValueTime>>) queries.clone());
+        sendMessage(response);
+    }
+
+    public void handleUpdateAttributes(UpdateAttributesMessage message) {
+        try {
+            validateUpdateAttributesMessage(message);
+            addMissingZones(new PathName(message.getPathName()));
+            ZMI zone = hierarchy.findDescendant(message.getPathName());
+            AttributesMap attributes = zone.getAttributes();
+            if (valueLower(attributes.get("timestamp"), message.getAttributes().get("timestamp"))) {
+                transferAttributes(message.getAttributes(), attributes);
+            } else {
+                System.out.println("DEBUG: not applying update with older attributes");
+            }
+        } catch (InvalidUpdateAttributesMessage e) {
+            System.out.println("ERROR: invalid UpdateAttributesMessage " + e.getMessage());
+        } catch (ZMI.NoSuchZoneException e) {
+            System.out.println("ERROR: zone should exist after being added");
+        }
+    }
+
+    public void handleUpdateQueries(UpdateQueriesMessage message) {
+        for (Entry<Attribute, Entry<ValueQuery, ValueTime>> entry : message.getQueries().entrySet()) {
+            Attribute attribute = entry.getKey();
+            ValueTime timestamp = entry.getValue().getValue();
+            Entry<ValueQuery, ValueTime> currentTimestampedQuery = queries.get(attribute);
+            if (currentTimestampedQuery == null || valueLower(currentTimestampedQuery.getValue(), timestamp)) {
+                queries.put(entry.getKey(), entry.getValue());
+            }
+        }
+    }
+
+    private boolean valueLower(Value a, Value b) {
+        return ((ValueBoolean) a.isLowerThan(b)).getValue();
+    }
+
+    private void validateUpdateAttributesMessage(UpdateAttributesMessage message) throws InvalidUpdateAttributesMessage {
+        validateZoneName(message);
+        validateHasTimeStamp(message);
+    }
+
+    private void validateZoneName(UpdateAttributesMessage message) throws InvalidUpdateAttributesMessage {
+        Value name = message.getAttributes().getOrNull("name");
+        if (message.getPathName().equals("/")) {
+            if (name != null && !name.isNull()) {
+                throw new InvalidUpdateAttributesMessage("The root zone should have a null name");
+            }
+        } else {
+            if (valueNonNullOfType(name, TypePrimitive.STRING)) {
+                ValueString nameString = (ValueString) name;
+                String expectedName = (new PathName(message.getPathName())).getSingletonName();
+                if (!nameString.getValue().equals(expectedName)) {
+                    throw new InvalidUpdateAttributesMessage("The zone's name attribute should match its path name");
+                }
+            } else {
+                throw new InvalidUpdateAttributesMessage("Zone attributes should have a name attribute of type String");
+            }
+        }
+    }
+
+    private void validateHasTimeStamp(UpdateAttributesMessage message) throws InvalidUpdateAttributesMessage {
+        if (!valueNonNullOfType(message.getAttributes().getOrNull("timestamp"), TypePrimitive.TIME)) {
+            throw new InvalidUpdateAttributesMessage("Zone attriutes should have a timestamp attribute of type Time");
+        }
+    }
+
+    private boolean valueNonNullOfType(Value value, Type type) {
+        return value != null && !value.isNull() && value.getType().isCompatible(type);
+    }
+
+    private void transferAttributes(AttributesMap fromAttributes, AttributesMap toAttributes) {
+        Iterator<Entry<Attribute, Value>> iterator = toAttributes.iterator();
+        while (iterator.hasNext()) {
+            Entry<Attribute, Value> entry = iterator.next();
+            Attribute attribute = entry.getKey();
+            Value newValue = fromAttributes.getOrNull(attribute);
+            if (newValue == null) {
+                iterator.remove();
+            }
+        }
+        for (Entry<Attribute, Value> entry : fromAttributes) {
+            toAttributes.addOrChange(entry.getKey(), entry.getValue());
+        }
+    }
+
+    private void addMissingZones(PathName path) {
+        try {
+            if (!hierarchy.descendantExists(path)) {
+                addMissingZones(path.levelUp());
+                ZMI parent = hierarchy.findDescendant(path.levelUp());
+                ZMI newSon = new ZMI(parent);
+                newSon.getAttributes().add("name", new ValueString(path.getSingletonName()));
+                newSon.getAttributes().add("timestamp", new ValueTime(0l));
+                parent.addSon(newSon);
+            }
+        } catch (ZMI.NoSuchZoneException e) {
+            System.out.println("ERROR: zone should exist after being added");
+        }
+    }
+
+    public ZMI getHierarchy() {
+        return hierarchy;
+    }
+
+    public HashMap<Attribute, Entry<ValueQuery, ValueTime>> getQueries() {
+        return queries;
+    }
+}
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/model/ZMI.java b/src/main/java/pl/edu/mimuw/cloudatlas/model/ZMI.java
index 7f2f604..54fbf43 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/model/ZMI.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/model/ZMI.java
@@ -111,6 +111,23 @@ public class ZMI implements Cloneable, Serializable {
         return descendant;
     }
 
+    public boolean descendantExists(PathName path) {
+        try {
+            findDescendant(path);
+            return true;
+        } catch (NoSuchZoneException e) {
+            return false;
+        }
+    }
+
+    /*
+     * Convenient version of findDescendant that takes String representation of
+     * path.
+     */
+    public ZMI findDescendant(String pathString) throws NoSuchZoneException {
+        return findDescendant(new PathName(pathString));
+    }
+
     /**
      * Gets the list of sons of this ZMI. Modifying a value in the returned list will cause an exception.
      *
diff --git a/src/test/java/pl/edu/mimuw/cloudatlas/agent/MockExecutor.java b/src/test/java/pl/edu/mimuw/cloudatlas/agent/MockExecutor.java
new file mode 100644
index 0000000..1da50ad
--- /dev/null
+++ b/src/test/java/pl/edu/mimuw/cloudatlas/agent/MockExecutor.java
@@ -0,0 +1,24 @@
+package pl.edu.mimuw.cloudatlas.agent;
+
+import java.util.concurrent.LinkedBlockingQueue;
+
+import pl.edu.mimuw.cloudatlas.agent.modules.Module;
+import pl.edu.mimuw.cloudatlas.agent.messages.AgentMessage;
+
+/*
+ * Instead of passing messages to an EventBus, this one just collects them
+ * locally for inspection in unit tests.
+ */
+public class MockExecutor extends Executor {
+    public LinkedBlockingQueue<AgentMessage> messagesToPass;
+
+    public MockExecutor(Module module) {
+        super(module);
+        messagesToPass = new LinkedBlockingQueue<AgentMessage>();
+    }
+
+    @Override
+    public void passMessage(AgentMessage message) throws InterruptedException {
+        messagesToPass.put(message);
+    }
+}
diff --git a/src/test/java/pl/edu/mimuw/cloudatlas/agent/modules/StanikTest.java b/src/test/java/pl/edu/mimuw/cloudatlas/agent/modules/StanikTest.java
new file mode 100644
index 0000000..aeaf19f
--- /dev/null
+++ b/src/test/java/pl/edu/mimuw/cloudatlas/agent/modules/StanikTest.java
@@ -0,0 +1,211 @@
+package pl.edu.mimuw.cloudatlas.agent.modules;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.AbstractMap.SimpleImmutableEntry;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import pl.edu.mimuw.cloudatlas.agent.messages.AgentMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.GetStateMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.StateMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.ResponseMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.UpdateAttributesMessage;
+import pl.edu.mimuw.cloudatlas.agent.messages.UpdateQueriesMessage;
+import pl.edu.mimuw.cloudatlas.agent.MockExecutor;
+import pl.edu.mimuw.cloudatlas.model.Attribute;
+import pl.edu.mimuw.cloudatlas.model.AttributesMap;
+import pl.edu.mimuw.cloudatlas.model.Value;
+import pl.edu.mimuw.cloudatlas.model.ValueInt;
+import pl.edu.mimuw.cloudatlas.model.ValueQuery;
+import pl.edu.mimuw.cloudatlas.model.ValueString;
+import pl.edu.mimuw.cloudatlas.model.ValueTime;
+import pl.edu.mimuw.cloudatlas.model.ZMI;
+
+import org.junit.Before;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class StanikTest {
+    private Stanik stanik;
+    private MockExecutor executor;
+
+    @Before
+    public void setupEventBus() {
+        stanik = new Stanik();
+        executor = new MockExecutor(stanik);
+    }
+
+    @Test
+    public void getEmptyState() throws Exception {
+        GetStateMessage message = new GetStateMessage("test_msg", 0, ModuleType.TEST, 42);
+        stanik.handleTyped(message);
+        assertEquals(1, executor.messagesToPass.size());
+        ResponseMessage receivedMessage = (ResponseMessage) executor.messagesToPass.take();
+        assertEquals(ModuleType.TEST, receivedMessage.getDestinationModule());
+        assertEquals(ResponseMessage.Type.STATE, receivedMessage.getType());
+        assertEquals(42, receivedMessage.getRequestId());
+        StateMessage stateMessage = (StateMessage) receivedMessage;
+        ZMI zmi = stateMessage.getZMI();
+        assertNull(zmi.getFather());
+        assertTrue(zmi.getSons().isEmpty());
+        assertEquals(1, iterableSize(zmi.getAttributes()));
+        Map<Attribute, Entry<ValueQuery, ValueTime>> queries = stateMessage.getQueries();
+        assertEquals(0, iterableSize(queries.keySet()));
+    }
+
+    @Test
+    public void hierarchyIsDeepCopy() throws Exception {
+        GetStateMessage message = new GetStateMessage("test_msg", 0, ModuleType.TEST, 42);
+        stanik.handleTyped(message);
+        StateMessage receivedMessage = (StateMessage) executor.messagesToPass.poll();
+        assertNotNull(receivedMessage);
+        AttributesMap attributes = receivedMessage.getZMI().getAttributes();
+        assertNull(attributes.getOrNull("foo"));
+        attributes.add("foo", new ValueInt(1337l));
+
+        GetStateMessage newMessage = new GetStateMessage("test_msg2", 123, ModuleType.TEST, 43);
+        stanik.handleTyped(newMessage);
+        StateMessage newReceivedMessage = (StateMessage) executor.messagesToPass.poll();
+        AttributesMap newAttributes = newReceivedMessage.getZMI().getAttributes();
+        assertNull(newAttributes.getOrNull("foo"));
+    }
+
+    @Test
+    public void updateRootAttributes() throws Exception {
+        AttributesMap attributes = new AttributesMap();
+        attributes.add("foo", new ValueInt(1337l));
+        attributes.add("bar", new ValueString("baz"));
+        attributes.add("timestamp", new ValueTime("2012/12/21 04:20:00.000"));
+        UpdateAttributesMessage message = new UpdateAttributesMessage("test_msg", 0, "/", attributes);
+        stanik.handleTyped(message);
+        AttributesMap actualAttributes = stanik.getHierarchy().getAttributes();
+        assertEquals(3, iterableSize(actualAttributes));
+        assertEquals(new ValueInt(1337l), actualAttributes.get("foo"));
+        assertEquals(new ValueString("baz"), actualAttributes.get("bar"));
+        assertEquals(new ValueTime("2012/12/21 04:20:00.000"), actualAttributes.getOrNull("timestamp"));
+    }
+
+    @Test
+    public void updateWithNewZone() throws Exception {
+        AttributesMap attributes = new AttributesMap();
+        attributes.add("foo", new ValueInt(1337l));
+        attributes.add("bar", new ValueString("baz"));
+        attributes.add("name", new ValueString("new"));
+        attributes.add("timestamp", new ValueTime("2012/12/21 04:20:00.000"));
+        UpdateAttributesMessage message = new UpdateAttributesMessage("test_msg", 0, "/new", attributes);
+        stanik.handleTyped(message);
+        AttributesMap actualAttributes = stanik.getHierarchy().findDescendant("/new").getAttributes();
+        assertEquals(4, iterableSize(actualAttributes));
+        assertEquals(new ValueInt(1337l), actualAttributes.getOrNull("foo"));
+        assertEquals(new ValueString("baz"), actualAttributes.getOrNull("bar"));
+        assertEquals(new ValueString("new"), actualAttributes.getOrNull("name"));
+        assertEquals(new ValueTime("2012/12/21 04:20:00.000"), actualAttributes.getOrNull("timestamp"));
+    }
+
+    @Test
+    public void updateWithRemovedAttributes() throws Exception {
+        AttributesMap attributes = new AttributesMap();
+        attributes.add("foo", new ValueInt(1337l));
+        attributes.add("bar", new ValueString("baz"));
+        UpdateAttributesMessage message = new UpdateAttributesMessage("test_msg", 0, "/", attributes);
+        attributes.add("timestamp", new ValueTime("2012/12/21 04:20:00.000"));
+        stanik.handleTyped(message);
+
+        AttributesMap newAttributes = new AttributesMap();
+        newAttributes.add("timestamp", new ValueTime("2012/12/21 04:20:42.000"));
+        newAttributes.add("foo", new ValueInt(1338l));
+        UpdateAttributesMessage newMessage = new UpdateAttributesMessage("test_msg2", 0, "/", newAttributes);
+        stanik.handleTyped(newMessage);
+
+        AttributesMap actualAttributes = stanik.getHierarchy().getAttributes();
+        assertEquals(2, iterableSize(actualAttributes));
+        assertEquals(new ValueInt(1338l), actualAttributes.getOrNull("foo"));
+        assertEquals(new ValueTime("2012/12/21 04:20:42.000"), actualAttributes.getOrNull("timestamp"));
+    }
+
+    @Test
+    public void dontApplyUpdateWithOlderTimestamp() throws Exception {
+        AttributesMap attributes = new AttributesMap();
+        attributes.add("foo", new ValueInt(1337l));
+        attributes.add("timestamp", new ValueTime("2012/12/21 04:20:00.000"));
+        UpdateAttributesMessage message = new UpdateAttributesMessage("test_msg", 0, "/", attributes);
+        stanik.handleTyped(message);
+
+        AttributesMap oldAttributes = new AttributesMap();
+        oldAttributes.add("foo", new ValueInt(1336l));
+        oldAttributes.add("timestamp", new ValueTime("2012/12/21 04:19:00.000"));
+        UpdateAttributesMessage newMessage = new UpdateAttributesMessage("test_msg2", 0, "/", oldAttributes);
+        stanik.handleTyped(newMessage);
+
+        AttributesMap actualAttributes = stanik.getHierarchy().getAttributes();
+        assertEquals(2, iterableSize(actualAttributes));
+        assertEquals(new ValueInt(1337l), actualAttributes.getOrNull("foo"));
+        assertEquals(new ValueTime("2012/12/21 04:20:00.000"), actualAttributes.getOrNull("timestamp"));
+    }
+
+    @Test
+    public void addQuery() throws Exception {
+        HashMap<Attribute, Entry<ValueQuery, ValueTime>> queries = new HashMap<Attribute, Entry<ValueQuery, ValueTime>>();
+        queries.put(new Attribute("&query"), new SimpleImmutableEntry(new ValueQuery("SELECT 1 AS one"), new ValueTime(42l)));
+        UpdateQueriesMessage message = new UpdateQueriesMessage("test_msg", 0, queries);
+        stanik.handleTyped(message);
+
+        HashMap<Attribute, Entry<ValueQuery, ValueTime>> actualQueries = stanik.getQueries();
+        assertEquals(1, iterableSize(actualQueries.keySet()));
+        assertTrue(actualQueries.containsKey(new Attribute("&query")));
+        Entry<ValueQuery, ValueTime> timestampedQuery = actualQueries.get(new Attribute("&query"));
+        assertEquals(new ValueTime(42l), timestampedQuery.getValue());
+        assertEquals(new ValueQuery("SELECT 1 AS one"), timestampedQuery.getKey());
+    }
+
+    @Test
+    public void updateQueries() throws Exception {
+        HashMap<Attribute, Entry<ValueQuery, ValueTime>> queries = new HashMap<Attribute, Entry<ValueQuery, ValueTime>>();
+        queries.put(new Attribute("&query1"), new SimpleImmutableEntry(new ValueQuery("SELECT 1 AS one"), new ValueTime(42l)));
+        queries.put(new Attribute("&query3"), new SimpleImmutableEntry(new ValueQuery("SELECT 23 AS x"), new ValueTime(43l)));
+        queries.put(new Attribute("&query4"), new SimpleImmutableEntry(new ValueQuery("SELECT 1000 AS foo"), new ValueTime(43l)));
+        UpdateQueriesMessage message = new UpdateQueriesMessage("test_msg", 0, queries);
+        stanik.handleTyped(message);
+
+        HashMap<Attribute, Entry<ValueQuery, ValueTime>> otherQueries = new HashMap<Attribute, Entry<ValueQuery, ValueTime>>();
+        otherQueries.put(new Attribute("&query1"), new SimpleImmutableEntry(new ValueQuery("SELECT 2 AS one"), new ValueTime(41l)));
+        otherQueries.put(new Attribute("&query2"), new SimpleImmutableEntry(new ValueQuery("SELECT 42 AS answer"), new ValueTime(39l)));
+        otherQueries.put(new Attribute("&query3"), new SimpleImmutableEntry(new ValueQuery("SELECT 17 AS y"), new ValueTime(44l)));
+        UpdateQueriesMessage otherMessage = new UpdateQueriesMessage("test_msg", 0, otherQueries);
+        stanik.handleTyped(otherMessage);
+
+        HashMap<Attribute, Entry<ValueQuery, ValueTime>> actualQueries = stanik.getQueries();
+        assertEquals(4, iterableSize(actualQueries.keySet()));
+        assertTrue(actualQueries.containsKey(new Attribute("&query1")));
+        assertTrue(actualQueries.containsKey(new Attribute("&query2")));
+        assertTrue(actualQueries.containsKey(new Attribute("&query3")));
+        assertTrue(actualQueries.containsKey(new Attribute("&query4")));
+
+        Entry<ValueQuery, ValueTime> timestampedQuery1 = actualQueries.get(new Attribute("&query1"));
+        assertEquals(new ValueTime(42l), timestampedQuery1.getValue());
+        assertEquals(new ValueQuery("SELECT 1 AS one"), timestampedQuery1.getKey());
+
+        Entry<ValueQuery, ValueTime> timestampedQuery2 = actualQueries.get(new Attribute("&query2"));
+        assertEquals(new ValueTime(39l), timestampedQuery2.getValue());
+        assertEquals(new ValueQuery("SELECT 42 AS answer"), timestampedQuery2.getKey());
+
+        Entry<ValueQuery, ValueTime> timestampedQuery3 = actualQueries.get(new Attribute("&query3"));
+        assertEquals(new ValueTime(44l), timestampedQuery3.getValue());
+        assertEquals(new ValueQuery("SELECT 17 AS y"), timestampedQuery3.getKey());
+
+        Entry<ValueQuery, ValueTime> timestampedQuery4 = actualQueries.get(new Attribute("&query4"));
+        assertEquals(new ValueTime(43l), timestampedQuery4.getValue());
+        assertEquals(new ValueQuery("SELECT 1000 AS foo"), timestampedQuery4.getKey());
+    }
+
+    public <T> int iterableSize(Iterable<T> iterable) {
+        int count = 0;
+        for (T attribute : iterable) {
+            count++;
+        }
+
+        return count;
+    }
+}