From 3e44c34a8e4af0426dd50e087dae45a06b8f50dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Magdalena=20Grodzi=C5=84ska?= <mag.grodzinska@gmail.com>
Date: Fri, 10 Jan 2020 22:34:47 +0100
Subject: Add initial gossip girl strategies implementation

---
 .../agent/modules/GossipGirlStrategies.java        | 98 +++++++++++++++++-----
 1 file changed, 78 insertions(+), 20 deletions(-)

(limited to 'src/main/java/pl/edu/mimuw/cloudatlas')

diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/GossipGirlStrategies.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/GossipGirlStrategies.java
index bf163d1..774e509 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/GossipGirlStrategies.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/GossipGirlStrategies.java
@@ -4,7 +4,7 @@ import org.apache.commons.math3.distribution.EnumeratedDistribution;
 import org.apache.commons.math3.util.Pair;
 import pl.edu.mimuw.cloudatlas.model.PathName;
 
-import java.util.ArrayList;
+import java.util.*;
 
 /**
  round robin with the same frequency for all levels,
@@ -14,6 +14,54 @@ import java.util.ArrayList;
  */
 
 public class GossipGirlStrategies {
+    private int roundRobinSameIt;
+    private ArrayList<Pair<String, Integer>> roundRobinExpFreqs;
+    private List<String> fullPathComponents;
+    private int fullPathLength;
+    private EnumeratedDistribution<String> expDist;
+    private EnumeratedDistribution<String> uniformDist;
+
+    public GossipGirlStrategies(PathName fullPath) {
+        fullPathComponents = fullPath.getComponents();
+        fullPathLength = fullPath.getComponents().size();
+        initUniformZoneProbabilities();
+        initExpZoneProbabilities();
+        roundRobinSameIt = 0;
+        initRoundRobinExpFreqs();
+    }
+
+    private void initExpZoneProbabilities() {
+        ArrayList<Pair<String, Double>> zoneProbabilities;
+        zoneProbabilities = new ArrayList<>(fullPathLength);
+
+        // TODO check if we decrease in good direction
+        for (int i = 0; i < fullPathLength; i++) {
+            Pair<String, Double> probPair = new Pair<String, Double>(fullPathComponents.get(i), Math.exp((double) i+1));
+            zoneProbabilities.add(probPair);
+        }
+
+        uniformDist = new EnumeratedDistribution<String>(zoneProbabilities);
+    }
+
+    private void initUniformZoneProbabilities() {
+        ArrayList<Pair<String, Double>> zoneProbabilities;
+        zoneProbabilities = new ArrayList<>(fullPathLength);
+
+        // TODO good direction
+        for (int i = 0; i < fullPathLength; i++) {
+            Pair<String, Double> probPair = new Pair<String, Double>(fullPathComponents.get(i), 1.0);
+            zoneProbabilities.add(probPair);
+        }
+
+        uniformDist = new EnumeratedDistribution<String>(zoneProbabilities);
+    }
+
+    private void initRoundRobinExpFreqs() {
+        roundRobinExpFreqs = new ArrayList<>();
+        for (String component : fullPathComponents) {
+            roundRobinExpFreqs.add(new Pair<String, Integer>(component, 0));
+        }
+    }
 
     public enum ZoneSelectionStrategy {
         ROUND_ROBIN_SAME_FREQ,
@@ -22,34 +70,44 @@ public class GossipGirlStrategies {
         RANDOM_DECR_EXP
     }
 
-    public PathName selectStrategy(PathName fullPath, ZoneSelectionStrategy selectionStrategy) {
-        PathName selectedPath;
-        ArrayList<PathName>
-        int fullPathLength = fullPath.getComponents().size();
+    private String updateRoundRobinExpFreqs() {
+        // TODO good direction
+        for (int i = roundRobinExpFreqs.size() - 1; i > 0; i--) {
+            Pair<String, Integer> p = roundRobinExpFreqs.get(i);
+            Pair<String, Integer> nextP = roundRobinExpFreqs.get(i-1);
 
-        switch(selectionStrategy) {
-            case (ZoneSelectionStrategy.ROUND_ROBIN_SAME_FREQ):
+            if (2 * p.getSecond() < nextP.getSecond()) {
+                roundRobinExpFreqs.add(i, new Pair<String, Integer>(p.getFirst(), p.getSecond() + 1));
+                return p.getFirst();
+            }
+        }
 
-                break;
-            case (ZoneSelectionStrategy.ROUND_ROBIN_EXP_FREQ):
+        Pair<String, Integer> rootPath = roundRobinExpFreqs.get(0);
+        roundRobinExpFreqs.add(0, new Pair<String, Integer>(rootPath.getFirst(), rootPath.getSecond() + 1));
+        return rootPath.getFirst();
+    }
 
+    public PathName selectStrategy(ZoneSelectionStrategy selectionStrategy) {
+        String selectedPath = null;
+
+        switch(selectionStrategy) {
+            case ROUND_ROBIN_SAME_FREQ:
+                selectedPath = fullPathComponents.get(roundRobinSameIt);
+                roundRobinSameIt = (roundRobinSameIt + 1) % fullPathLength;
+                break;
+            case ROUND_ROBIN_EXP_FREQ:
+                selectedPath = updateRoundRobinExpFreqs();
                 break;
-            case (ZoneSelectionStrategy.RANDOM_UNFIORM):
-                ArrayList<Pair<PathName, Double>> zoneProbabilities = new ArrayList<>(fullPathLength);
-                EnumeratedDistribution dist = new EnumeratedDistribution();
-                for (int i = 1; i < fullPathLength; i++) {
-                    zoneProbabilities.add(fullPath.);
-                }
+            case RANDOM_UNFIORM:
+                selectedPath = uniformDist.sample();
                 break;
-            case (ZoneSelectionStrategy.RANDOM_DECR_EXP):
+            case RANDOM_DECR_EXP:
+                selectedPath = expDist.sample();
                 break;
             default:
                 throw new UnsupportedOperationException("Such strategy doesn't exist");
         }
 
-        return selectedPath;
+        return new PathName(selectedPath);
     }
-
-
-
 }
-- 
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