Merge pull request #85 from m-chrzan/staleness

Staleness

4 files changed, 75 insertions, 16 deletions

diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/Agent.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/Agent.java
index 0efa710..26f0e0b 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/agent/Agent.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/Agent.java
@@ -46,7 +46,8 @@ public class Agent {
         HashMap<ModuleType, Module> modules = new HashMap<ModuleType, Module>();
         modules.put(ModuleType.TIMER_SCHEDULER, new TimerScheduler(ModuleType.TIMER_SCHEDULER));
         modules.put(ModuleType.RMI, new Remik());
-        modules.put(ModuleType.STATE, new Stanik());
+        Long freshnessPeriod = new Long(System.getProperty("freshness_period"));
+        modules.put(ModuleType.STATE, new Stanik(freshnessPeriod));
         modules.put(ModuleType.QUERY, new Qurnik());
         // TODO add modules as we implement them
         return modules;
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
index 3e5b790..6761c94 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Stanik.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/Stanik.java
@@ -1,6 +1,8 @@
 package pl.edu.mimuw.cloudatlas.agent.modules;
 
 import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map.Entry;
 
 import pl.edu.mimuw.cloudatlas.agent.messages.AgentMessage;
@@ -19,6 +21,7 @@ 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.ValueDuration;
 import pl.edu.mimuw.cloudatlas.model.ValueQuery;
 import pl.edu.mimuw.cloudatlas.model.ValueString;
 import pl.edu.mimuw.cloudatlas.model.ValueTime;
@@ -34,12 +37,18 @@ public class Stanik extends Module {
 
     private ZMI hierarchy;
     private HashMap<Attribute, Entry<ValueQuery, ValueTime>> queries;
+    private long freshnessPeriod;
 
-    public Stanik() {
+    public Stanik(long freshnessPeriod) {
         super(ModuleType.STATE);
         hierarchy = new ZMI();
         queries = new HashMap<Attribute, Entry<ValueQuery, ValueTime>>();
         hierarchy.getAttributes().add("timestamp", new ValueTime(0l));
+        this.freshnessPeriod = freshnessPeriod;
+    }
+
+    public Stanik() {
+        this(60 * 1000);
     }
 
     public void handleTyped(StanikMessage message) throws InterruptedException, InvalidMessageType {
@@ -65,6 +74,7 @@ public class Stanik extends Module {
     }
 
     public void handleGetState(GetStateMessage message) throws InterruptedException {
+        pruneHierarchy();
         StateMessage response = new StateMessage(
             "",
             message.getRequestingModule(),
@@ -76,6 +86,40 @@ public class Stanik extends Module {
         sendMessage(response);
     }
 
+    private void pruneHierarchy() {
+        ValueTime now = ValueUtils.currentTime();
+        pruneZMI(hierarchy, now);
+    }
+
+    private boolean pruneZMI(ZMI zmi, ValueTime time) {
+        Value timestamp = zmi.getAttributes().get("timestamp");
+
+        boolean isLeaf = zmi.getSons().isEmpty();
+
+        List<ZMI> sonsToRemove = new LinkedList();
+        if (ValueUtils.valueLower(timestamp, time.subtract(new ValueDuration(freshnessPeriod)))) {
+            if (zmi.getFather() != null) {
+                return true;
+            }
+        } else {
+            for (ZMI son : zmi.getSons()) {
+                if (pruneZMI(son, time)) {
+                    sonsToRemove.add(son);
+                }
+            }
+        }
+
+        for (ZMI son : sonsToRemove) {
+            zmi.removeSon(son);
+        }
+
+        if (!isLeaf && zmi.getSons().isEmpty()) {
+            return true;
+        }
+
+        return false;
+    }
+
     public void handleRemoveZMI(RemoveZMIMessage message) {
         try {
             ZMI zmi = hierarchy.findDescendant(new PathName(message.getPathName()));
@@ -113,13 +157,20 @@ public class Stanik extends Module {
     public void handleUpdateAttributes(UpdateAttributesMessage message) {
         try {
             validateUpdateAttributesMessage(message);
-            addMissingZones(new PathName(message.getPathName()));
-            ZMI zone = hierarchy.findDescendant(message.getPathName());
-            AttributesMap attributes = zone.getAttributes();
-            if (ValueUtils.valueLower(attributes.get("timestamp"), message.getAttributes().get("timestamp"))) {
-                AttributesUtil.transferAttributes(message.getAttributes(), attributes);
+            if (!ValueUtils.valueLower(
+                        message.getAttributes().get("timestamp"),
+                        new ValueTime(System.currentTimeMillis() - freshnessPeriod)
+            )) {
+                addMissingZones(new PathName(message.getPathName()));
+                ZMI zone = hierarchy.findDescendant(message.getPathName());
+                AttributesMap attributes = zone.getAttributes();
+                if (ValueUtils.valueLower(attributes.get("timestamp"), message.getAttributes().get("timestamp"))) {
+                    AttributesUtil.transferAttributes(message.getAttributes(), attributes);
+                } else {
+                    System.out.println("DEBUG: not applying update with older attributes");
+                }
             } else {
-                System.out.println("DEBUG: not applying update with older attributes");
+                System.out.println("DEBUG: not applying update with stale attributes");
             }
         } catch (InvalidUpdateAttributesMessage e) {
             System.out.println("ERROR: invalid UpdateAttributesMessage " + e.getMessage());
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/interpreter/Main.java b/src/main/java/pl/edu/mimuw/cloudatlas/interpreter/Main.java
index 1e0bb4f..7419ad4 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/interpreter/Main.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/interpreter/Main.java
@@ -50,6 +50,7 @@ import pl.edu.mimuw.cloudatlas.model.ValueList;
 import pl.edu.mimuw.cloudatlas.model.ValueSet;
 import pl.edu.mimuw.cloudatlas.model.ValueString;
 import pl.edu.mimuw.cloudatlas.model.ValueTime;
+import pl.edu.mimuw.cloudatlas.model.ValueUtils;
 import pl.edu.mimuw.cloudatlas.model.ZMI;
 
 public class Main {
@@ -274,29 +275,31 @@ public class Main {
 
         List<Value> list;
 
+        ValueTime time = ValueUtils.currentTime();
+
         ZMI root = new ZMI();
         root.getAttributes().add("level", new ValueInt(0l));
         root.getAttributes().add("name", new ValueString(null));
-        root.getAttributes().add("timestamp", new ValueTime(10l));
+        root.getAttributes().add("timestamp", time);
 
         ZMI uw = new ZMI(root);
         root.addSon(uw);
         uw.getAttributes().add("level", new ValueInt(1l));
         uw.getAttributes().add("name", new ValueString("uw"));
-        uw.getAttributes().add("timestamp", new ValueTime(10l));
+        uw.getAttributes().add("timestamp", time);
 
         ZMI pjwstk = new ZMI(root);
         root.addSon(pjwstk);
         pjwstk.getAttributes().add("level", new ValueInt(1l));
         pjwstk.getAttributes().add("name", new ValueString("pjwstk"));
-        pjwstk.getAttributes().add("timestamp", new ValueTime(10l));
+        pjwstk.getAttributes().add("timestamp", time);
 
         ZMI violet07 = new ZMI(uw);
         uw.addSon(violet07);
         violet07.getAttributes().add("level", new ValueInt(2l));
         violet07.getAttributes().add("name", new ValueString("violet07"));
         violet07.getAttributes().add("owner", new ValueString("/uw/violet07"));
-        violet07.getAttributes().add("timestamp", new ValueTime("2012/11/09 18:00:00.000"));
+        violet07.getAttributes().add("timestamp", time);
         list = Arrays.asList(new Value[] {
             violet07Contact, khaki31Contact, khaki13Contact
         });
@@ -322,7 +325,7 @@ public class Main {
         khaki31.getAttributes().add("level", new ValueInt(2l));
         khaki31.getAttributes().add("name", new ValueString("khaki31"));
         khaki31.getAttributes().add("owner", new ValueString("/uw/khaki31"));
-        khaki31.getAttributes().add("timestamp", new ValueTime("2012/11/09 20:03:00.000"));
+        khaki31.getAttributes().add("timestamp", time);
         list = Arrays.asList(new Value[] {
             violet08Contact
         });
@@ -348,7 +351,7 @@ public class Main {
         khaki13.getAttributes().add("level", new ValueInt(2l));
         khaki13.getAttributes().add("name", new ValueString("khaki13"));
         khaki13.getAttributes().add("owner", new ValueString("/uw/khaki13"));
-        khaki13.getAttributes().add("timestamp", new ValueTime("2012/11/09 21:03:00.000"));
+        khaki13.getAttributes().add("timestamp", time);
         list = Arrays.asList(new Value[] {
             khaki14Contact, khaki32Contact
         });
@@ -372,7 +375,7 @@ public class Main {
         whatever01.getAttributes().add("level", new ValueInt(2l));
         whatever01.getAttributes().add("name", new ValueString("whatever01"));
         whatever01.getAttributes().add("owner", new ValueString("/pjwstk/whatever01"));
-        whatever01.getAttributes().add("timestamp", new ValueTime("2012/11/09 21:12:00.000"));
+        whatever01.getAttributes().add("timestamp", time);
         list = Arrays.asList(new Value[] {
             whatever02Contact,
         });
@@ -396,7 +399,7 @@ public class Main {
         whatever02.getAttributes().add("level", new ValueInt(2l));
         whatever02.getAttributes().add("name", new ValueString("whatever02"));
         whatever02.getAttributes().add("owner", new ValueString("/pjwstk/whatever02"));
-        whatever02.getAttributes().add("timestamp", new ValueTime("2012/11/09 21:13:00.000"));
+        whatever02.getAttributes().add("timestamp", time);
         list = Arrays.asList(new Value[] {
             whatever01Contact,
         });
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/model/ValueUtils.java b/src/main/java/pl/edu/mimuw/cloudatlas/model/ValueUtils.java
index 02b2ce4..3df8231 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/model/ValueUtils.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/model/ValueUtils.java
@@ -8,4 +8,8 @@ public class ValueUtils {
     public static boolean valueLower(Value a, Value b) {
         return ((ValueBoolean) a.isLowerThan(b)).getValue();
     }
+
+    public static ValueTime currentTime() {
+        return new ValueTime(System.currentTimeMillis());
+    }
 }