From b90a87b1490015d8d6ae1e337d0b18871bd3d294 Mon Sep 17 00:00:00 2001
From: Joshua Kissoon <JoshuaKissoon@gmail.com>
Date: Wed, 7 May 2014 09:26:29 +0530
Subject: [PATCH] Statistician - Added measuring the route Length (Hop Length)
 of content lookup operation

---
 src/kademlia/KademliaNode.java                    |  4 ++--
 src/kademlia/Statistician.java                    | 10 +++++++---
 .../operation/ContentLookupOperation.java         | 15 +++++++++++++++
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/src/kademlia/KademliaNode.java b/src/kademlia/KademliaNode.java
index 143ed6c..c94aef0 100644
--- a/src/kademlia/KademliaNode.java
+++ b/src/kademlia/KademliaNode.java
@@ -329,7 +329,7 @@ public class KademliaNode
         {
             /* If the content exist in our own DHT, then return it. */
             long endTime = System.nanoTime();
-            this.statistician.addContentLookupTime(endTime - startTime);
+            this.statistician.addContentLookup(endTime - startTime, 0);
             return this.dht.get(param);
         }
 
@@ -337,7 +337,7 @@ public class KademliaNode
         ContentLookupOperation clo = new ContentLookupOperation(server, this, param, this.config);
         clo.execute();
         long endTime = System.nanoTime();
-        this.statistician.addContentLookupTime(endTime - startTime);
+        this.statistician.addContentLookup(endTime - startTime, clo.routeLength());
         return clo.getContentFound();
     }
 
diff --git a/src/kademlia/Statistician.java b/src/kademlia/Statistician.java
index ab6fd29..2875d7b 100644
--- a/src/kademlia/Statistician.java
+++ b/src/kademlia/Statistician.java
@@ -17,9 +17,10 @@ public class Statistician
     /* Bootstrap timings */
     private long bootstrapTime;
 
-    /* Content lookup operation timing */
+    /* Content lookup operation timing & route length */
     private int numContentLookups;
     private long totalContentLookupTime;
+    private long totalRouteLength;
 
     
     {
@@ -28,6 +29,7 @@ public class Statistician
         this.bootstrapTime = 0;
         this.numContentLookups = 0;
         this.totalContentLookupTime = 0;
+        this.totalRouteLength = 0;
     }
 
     /**
@@ -84,12 +86,14 @@ public class Statistician
     /**
      * Add the timing for a new content lookup operation that took place
      *
-     * @param time The time the content lookup took in nanoseconds
+     * @param time        The time the content lookup took in nanoseconds
+     * @param routeLength The length of the route it took to get the content
      */
-    public void addContentLookupTime(long time)
+    public void addContentLookup(long time, int routeLength)
     {
         this.numContentLookups++;
         this.totalContentLookupTime += time;
+        this.totalRouteLength += routeLength;
     }
 
     public int numContentLookups()
diff --git a/src/kademlia/operation/ContentLookupOperation.java b/src/kademlia/operation/ContentLookupOperation.java
index 2fd14b5..fcbe2a0 100644
--- a/src/kademlia/operation/ContentLookupOperation.java
+++ b/src/kademlia/operation/ContentLookupOperation.java
@@ -56,10 +56,14 @@ public class ContentLookupOperation implements Operation, Receiver
     /* Used to sort nodes */
     private final Comparator comparator;
 
+    /* Statistical information */
+    private int routeLength;    // Length of the route to find this content
+
     
     {
         messagesTransiting = new HashMap<>();
         isContentFound = false;
+        routeLength = 1;
     }
 
     /**
@@ -250,6 +254,9 @@ public class ContentLookupOperation implements Operation, Receiver
         }
         else
         {
+            /* Our hop length is increased */
+            this.routeLength++;
+
             /* The reply received is a NodeReplyMessage with nodes closest to the content needed */
             NodeReplyMessage msg = (NodeReplyMessage) incoming;
 
@@ -311,4 +318,12 @@ public class ContentLookupOperation implements Operation, Receiver
             throw new ContentNotFoundException("No Value was found for the given key.");
         }
     }
+
+    /**
+     * @return How many hops it took in order to get to the content.
+     */
+    public int routeLength()
+    {
+        return this.routeLength;
+    }
 }