From 43f28695d0699e666a71e15a2236a47c11c8c251 Mon Sep 17 00:00:00 2001
From: Alexander Munch-Hansen <alexmunchhansen@gmail.com>
Date: Thu, 5 Dec 2019 17:01:31 +0100
Subject: [PATCH] pls

---
 .../balancedBlockClient.java                  | 78 +++++++++++++++++++
 .../balancedBlockServer.java                  | 49 ++++++++++++
 2 files changed, 127 insertions(+)

diff --git a/pir/src/main/java/dk/au/pir/protocols/balancedBlockScheme/balancedBlockClient.java b/pir/src/main/java/dk/au/pir/protocols/balancedBlockScheme/balancedBlockClient.java
index 4bf7380..0cb9edd 100644
--- a/pir/src/main/java/dk/au/pir/protocols/balancedBlockScheme/balancedBlockClient.java
+++ b/pir/src/main/java/dk/au/pir/protocols/balancedBlockScheme/balancedBlockClient.java
@@ -1,4 +1,82 @@
 package dk.au.pir.protocols.balancedBlockScheme;
 
+import dk.au.pir.databases.Database;
+import dk.au.pir.databases.MemoryDatabase;
+import dk.au.pir.profilers.Profiler;
+import dk.au.pir.protocols.simple.SimpleClient;
+import dk.au.pir.protocols.simple.SimpleServer;
+import dk.au.pir.settings.PIRSettings;
+
+import java.util.Arrays;
+import java.util.Random;
+
 public class balancedBlockClient {
+
+
+    private final PIRSettings settings;
+    private final balancedBlockServer[] servers;
+    private final int sqrtSize;
+    private Profiler profiler;
+
+    public balancedBlockClient(PIRSettings settings, balancedBlockServer[] servers, Profiler profiler) {
+        this.settings = settings;
+        this.servers = servers;
+        this.profiler = profiler;
+        this.sqrtSize = (int) Math.ceil(Math.sqrt(settings.getDatabaseSize()));
+    }
+
+    public int[] selectIndexes(int n) {
+        int[] indexes = new int[n];
+        Random rand = new Random();
+        for (int i=0; i < n; i++) {
+            indexes[i] = rand.nextInt(2);
+        }
+        return indexes;
+    }
+
+    public int receiveBit(int index) {
+        /**
+         * PLAN:
+         *   Divide n into sqrt(n)
+         *   Compute which index we want find this within a block
+         *   Send block
+         */
+
+        int[] S1 = selectIndexes(this.sqrtSize);
+        int[] S2 = S1.clone();
+
+
+
+        int impBlock = index % this.sqrtSize;
+        System.out.println("ImpBlock: " + impBlock);
+        if (S1[index % this.sqrtSize] == 1) {
+            S2[index % this.sqrtSize] = 0;  // Remove the index, if it's contained in S.
+        } else {
+            S2[index % this.sqrtSize] = 1;
+        }
+
+        System.out.println("S1: " + Arrays.toString(S1));
+        System.out.println("S2: " + Arrays.toString(S2));
+
+
+        int[] resBit1 = this.servers[0].computeBit(S1);
+        int[] resBit2 = this.servers[1].computeBit(S2);
+
+        return ((resBit1[impBlock] + resBit2[impBlock]) % 2);
+
+    }
+
+    public static void main(String[] args) {
+        PIRSettings settings = new PIRSettings(16, 2, 1);
+        balancedBlockServer[] servers = new balancedBlockServer[settings.getNumServers()];
+
+        Database database = new MemoryDatabase(settings, new int[] {0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0});
+
+        for (int i = 0; i < settings.getNumServers(); i++) {
+            servers[i] = new balancedBlockServer(database, settings);
+        }
+        balancedBlockClient client = new balancedBlockClient(settings, servers, null);
+        System.out.println(client.receiveBit(6));
+    }
 }
+
diff --git a/pir/src/main/java/dk/au/pir/protocols/balancedBlockScheme/balancedBlockServer.java b/pir/src/main/java/dk/au/pir/protocols/balancedBlockScheme/balancedBlockServer.java
index a2b4961..cd61086 100644
--- a/pir/src/main/java/dk/au/pir/protocols/balancedBlockScheme/balancedBlockServer.java
+++ b/pir/src/main/java/dk/au/pir/protocols/balancedBlockScheme/balancedBlockServer.java
@@ -1,4 +1,53 @@
 package dk.au.pir.protocols.balancedBlockScheme;
 
+import dk.au.pir.databases.Database;
+import dk.au.pir.settings.PIRSettings;
+
+import java.util.Arrays;
+
 public class balancedBlockServer {
+
+
+    private final Database database;
+    private final PIRSettings settings;
+    private final int sqrtSize;
+
+    public balancedBlockServer(Database database, PIRSettings settings) {
+        this.database = database;
+        this.settings = settings;
+        this.sqrtSize = (int) Math.ceil(Math.sqrt(settings.getDatabaseSize()));
+    }
+
+    public int[] computeBit(int[] indexes) {
+        int[] db = database.getX();
+
+        /*
+            Divide n in the sqrt(n) size chunks
+            Get sqrt(n) size array from client, which we cycle through sqrt(n) times
+            We return a sqrt(n) size list of bits. One from each cycle.
+         */
+
+        int[] resList = new int[this.sqrtSize];
+
+        for (int i = 0; i < this.sqrtSize; i++) {
+
+            int tmpRes = 0;
+
+            for (int j = 0; j < this.sqrtSize; j++) {
+                try {
+                    boolean test = indexes[j] == 1;
+                    if (test) {
+                        tmpRes = (tmpRes + db[j + (this.sqrtSize * i)]) % 2;
+                    }
+
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    tmpRes = (tmpRes) % 2;
+                }
+            }
+            resList[i] = tmpRes;
+        }
+        System.out.println("ResList: " + Arrays.toString(resList));
+
+        return resList;
+    }
 }