First (untested) version of BB Client with full batch support

bulletin-board-client/src/main/java/meerkat/bulletinboard/BatchDataContainer.java

@@ -0,0 +1,25 @@
+package meerkat.bulletinboard;
+
+import com.google.protobuf.ByteString;
+import meerkat.protobuf.BulletinBoardAPI.BatchData;
+
+import java.util.List;
+
+/**
+ * Created by Arbel Deutsch Peled on 17-Jan-16.
+ * Used to store the complete data required for sending a batch data list inside a single object
+ */
+public class BatchDataContainer {
+
+    public final byte[] signerId;
+    public final int batchId;
+    public final List<BatchData> batchDataList;
+    public final int startPosition;
+
+    public BatchDataContainer(byte[] signerId, int batchId, List<BatchData> batchDataList, int startPosition) {
+        this.signerId = signerId;
+        this.batchId = batchId;
+        this.batchDataList = batchDataList;
+        this.startPosition = startPosition;
+    }
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/SingleServerBulletinBoardClient.java

@@ -5,9 +5,7 @@ import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListeningScheduledExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.protobuf.ByteString;
-import meerkat.bulletinboard.workers.SingleServerGetRedundancyWorker;
+import meerkat.bulletinboard.workers.singleserver.*;
-import meerkat.bulletinboard.workers.SingleServerPostMessageWorker;
-import meerkat.bulletinboard.workers.SingleServerReadMessagesWorker;
 import meerkat.protobuf.BulletinBoardAPI.*;
 import meerkat.protobuf.Voting.BulletinBoardClientParams;
 
@@ -30,6 +28,8 @@ public class SingleServerBulletinBoardClient extends SimpleBulletinBoardClient i
 
     protected ListeningScheduledExecutorService executorService;
 
+    protected BatchDigest batchDigest;
+
     private long lastServerErrorTime;
 
     protected final long failDelayInMilliseconds;
@@ -136,6 +136,9 @@ public class SingleServerBulletinBoardClient extends SimpleBulletinBoardClient i
         // Perform usual setup
         super.init(clientParams);
 
+        // Wrap the Digest into a BatchDigest
+        batchDigest = new GenericBatchDigest(digest);
+
         // Remove all but first DB address
         String dbAddress = meerkatDBs.get(0);
         meerkatDBs = new LinkedList<String>();
@@ -153,19 +156,124 @@ public class SingleServerBulletinBoardClient extends SimpleBulletinBoardClient i
         scheduleWorker(worker, new RetryCallback(worker, callback));
 
         // Calculate the correct message ID and return it
-        digest.reset();
+        batchDigest.reset();
-        digest.update(msg.getMsg());
+        batchDigest.update(msg.getMsg());
-        return MessageID.newBuilder().setID(ByteString.copyFrom(digest.digest())).build();
+        return batchDigest.digestAsMessageID();
 
     }
 
+    private class PostBatchDataCallback implements ClientCallback<Boolean> {
+
+        private CompleteBatch completeBatch;
+        ClientCallback<Boolean> callback;
+
+        public PostBatchDataCallback(CompleteBatch completeBatch, ClientCallback<Boolean> callback) {
+            this.completeBatch = completeBatch;
+            this.callback = callback;
+        }
+
+        @Override
+        public void handleCallback(Boolean msg) {
+            closeBatch(
+                    CloseBatchMessage.newBuilder()
+                            .setBatchId(completeBatch.getBeginBatchMessage().getBatchId())
+                            .setSig(completeBatch.getSignature())
+                            .setBatchLength(completeBatch.getBatchDataList().size())
+                            .build(),
+                    callback
+            );
+        }
+
+        @Override
+        public void handleFailure(Throwable t) {
+            callback.handleFailure(t);
+        }
+
+    }
+
+    private class BeginBatchCallback implements ClientCallback<Boolean> {
+
+        private CompleteBatch completeBatch;
+        ClientCallback<Boolean> callback;
+
+        public BeginBatchCallback(CompleteBatch completeBatch, ClientCallback<Boolean> callback) {
+            this.completeBatch = completeBatch;
+            this.callback = callback;
+        }
+
+        @Override
+        public void handleCallback(Boolean msg) {
+
+            postBatchData(
+                    completeBatch.getBeginBatchMessage().getSignerId(),
+                    completeBatch.getBeginBatchMessage().getBatchId(),
+                    completeBatch.getBatchDataList(),
+                    0,
+                    new PostBatchDataCallback(completeBatch,callback));
+        }
+
+        @Override
+        public void handleFailure(Throwable t) {
+            callback.handleFailure(t);
+        }
+    }
+
     @Override
     public MessageID postBatch(CompleteBatch completeBatch, ClientCallback<Boolean> callback) {
-        return null;
+
+        beginBatch(
+                completeBatch.getBeginBatchMessage(),
+                new BeginBatchCallback(completeBatch, callback)
+        );
+
+        batchDigest.update(completeBatch);
+
+        return batchDigest.digestAsMessageID();
+
     }
 
     @Override
-    public void beginBatch(byte[] signerId, int batchId, List<String> tagList, ClientCallback<Boolean> callback) {
+    public void beginBatch(BeginBatchMessage beginBatchMessage, ClientCallback<Boolean> callback) {
+
+        // Create worker with redundancy 1 and MAX_RETRIES retries
+        SingleServerBeginBatchWorker worker =
+                new SingleServerBeginBatchWorker(meerkatDBs.get(0), beginBatchMessage, MAX_RETRIES);
+
+        // Submit worker and create callback
+        scheduleWorker(worker, new RetryCallback(worker, callback));
+
+    }
+
+    @Override
+    public void postBatchData(ByteString signerId, int batchId, List<BatchData> batchDataList,
+                          int startPosition, ClientCallback<Boolean> callback) {
+
+        BatchMessage.Builder builder = BatchMessage.newBuilder()
+                .setSignerId(signerId)
+                .setBatchId(batchId);
+
+        // Iterate through data list
+
+        for (BatchData data : batchDataList) {
+            builder.setSerialNum(startPosition).setData(data);
+
+            // Create worker with redundancy 1 and MAX_RETRIES retries
+            SingleServerPostBatchWorker worker =
+                    new SingleServerPostBatchWorker(meerkatDBs.get(0), builder.build(), MAX_RETRIES);
+
+            // Create worker with redundancy 1 and MAX_RETRIES retries
+            scheduleWorker(worker, new RetryCallback(worker, callback));
+
+            // Increment position in batch
+            startPosition++;
+        }
+
+    }
+
+    @Override
+    public void postBatchData(ByteString signerId, int batchId, List<BatchData> batchDataList, ClientCallback<Boolean> callback) {
+
+        postBatchData(signerId, batchId, batchDataList, 0, callback);
 
     }
 
@@ -173,15 +281,26 @@ public class SingleServerBulletinBoardClient extends SimpleBulletinBoardClient i
     public void postBatchData(byte[] signerId, int batchId, List<BatchData> batchDataList,
                               int startPosition, ClientCallback<Boolean> callback) {
 
+        postBatchData(ByteString.copyFrom(signerId), batchId, batchDataList, startPosition, callback);
+
     }
 
     @Override
     public void postBatchData(byte[] signerId, int batchId, List<BatchData> batchDataList, ClientCallback<Boolean> callback) {
 
+        postBatchData(signerId, batchId, batchDataList, 0, callback);
+
     }
 
     @Override
-    public void closeBatch(CloseBatchMessage closeBatchMessage, ClientCallback<?> callback) {
+    public void closeBatch(CloseBatchMessage closeBatchMessage, ClientCallback<Boolean> callback) {
+
+        // Create worker with redundancy 1 and MAX_RETRIES retries
+        SingleServerCloseBatchWorker worker =
+                new SingleServerCloseBatchWorker(meerkatDBs.get(0), closeBatchMessage, MAX_RETRIES);
+
+        // Submit worker and create callback
+        scheduleWorker(worker, new RetryCallback(worker, callback));
 
     }
 
@@ -208,7 +327,13 @@ public class SingleServerBulletinBoardClient extends SimpleBulletinBoardClient i
     }
 
     @Override
-    public void readBatch(byte[] signerId, int batchId, ClientCallback<CompleteBatch> callback) {
+    public void readBatch(BatchSpecificationMessage batchSpecificationMessage, ClientCallback<CompleteBatch> callback) {
+
+        // Create job with no retries
+        SingleServerReadBatchWorker worker = new SingleServerReadBatchWorker(meerkatDBs.get(0), batchSpecificationMessage, 1);
+
+        // Submit job and create callback
+        scheduleWorker(worker, new RetryCallback(worker, callback));
 
     }
 

bulletin-board-client/src/main/java/meerkat/bulletinboard/ThreadedBulletinBoardClient.java

@@ -2,9 +2,7 @@ package meerkat.bulletinboard;
 
 import com.google.protobuf.ByteString;
 
-import meerkat.bulletinboard.workers.MultiServerGetRedundancyWorker;
+import meerkat.bulletinboard.workers.multiserver.*;
-import meerkat.bulletinboard.workers.MultiServerPostMessageWorker;
-import meerkat.bulletinboard.workers.MultiServerReadMessagesWorker;
 import meerkat.comm.CommunicationException;
 import meerkat.protobuf.BulletinBoardAPI.*;
 import meerkat.protobuf.Voting.*;
@@ -31,6 +29,8 @@ public class ThreadedBulletinBoardClient extends SimpleBulletinBoardClient imple
     // Per-server clients
     List<SingleServerBulletinBoardClient> clients;
 
+    BatchDigest batchDigest;
+
     private final static int POST_MESSAGE_RETRY_NUM = 3;
     private final static int READ_MESSAGES_RETRY_NUM = 1;
     private final static int GET_REDUNDANCY_RETRY_NUM = 1;
@@ -51,6 +51,8 @@ public class ThreadedBulletinBoardClient extends SimpleBulletinBoardClient imple
 
         super.init(clientParams);
 
+        batchDigest = new GenericBatchDigest(digest);
+
         minAbsoluteRedundancy = (int) (clientParams.getMinRedundancy() * clientParams.getBulletinBoardAddressCount());
 
         executorService = Executors.newFixedThreadPool(JOBS_THREAD_NUM);
@@ -84,42 +86,88 @@ public class ThreadedBulletinBoardClient extends SimpleBulletinBoardClient imple
         executorService.submit(worker);
 
         // Calculate the correct message ID and return it
-        digest.reset();
+        batchDigest.reset();
-        digest.update(msg.getMsg());
+        batchDigest.update(msg.getMsg());
-        return MessageID.newBuilder().setID(ByteString.copyFrom(digest.digest())).build();
+        return batchDigest.digestAsMessageID();
 
     }
 
     @Override
     public MessageID postBatch(CompleteBatch completeBatch, ClientCallback<Boolean> callback) {
 
-        return null;    // TODO: write this
+        // Create job
+        MultiServerPostBatchWorker worker =
+                new MultiServerPostBatchWorker(clients, minAbsoluteRedundancy, completeBatch, POST_MESSAGE_RETRY_NUM, callback);
+
+        // Submit job
+        executorService.submit(worker);
+
+        // Calculate the correct message ID and return it
+        batchDigest.reset();
+        batchDigest.update(completeBatch);
+        return batchDigest.digestAsMessageID();
 
     }
 
     @Override
-    public void beginBatch(byte[] signerId, int batchId, List<String> tagList, ClientCallback<Boolean> callback) {
+    public void beginBatch(BeginBatchMessage beginBatchMessage, ClientCallback<Boolean> callback) {
-        // TODO: write this
+
+        // Create job
+        MultiServerBeginBatchWorker worker =
+                new MultiServerBeginBatchWorker(clients, minAbsoluteRedundancy, beginBatchMessage, POST_MESSAGE_RETRY_NUM, callback);
+
+        // Submit job
+        executorService.submit(worker);
+
     }
 
     @Override
     public void postBatchData(byte[] signerId, int batchId, List<BatchData> batchDataList,
-                                   int startPosition, ClientCallback<Boolean> callback) {
+                              int startPosition, ClientCallback<Boolean> callback) {
 
-        // TODO: write this
+        BatchDataContainer batchDataContainer = new BatchDataContainer(signerId, batchId, batchDataList, startPosition);
+
+        // Create job
+        MultiServerPostBatchDataWorker worker =
+                new MultiServerPostBatchDataWorker(clients, minAbsoluteRedundancy, batchDataContainer, POST_MESSAGE_RETRY_NUM, callback);
+
+        // Submit job
+        executorService.submit(worker);
 
     }
 
     @Override
     public void postBatchData(byte[] signerId, int batchId, List<BatchData> batchDataList, ClientCallback<Boolean> callback) {
 
-        postBatchData(signerId, batchId, batchDataList, 0, callback);   // Write batch from beginning
+        postBatchData(signerId, batchId, batchDataList, 0, callback);
 
     }
 
     @Override
-    public void closeBatch(CloseBatchMessage closeBatchMessage, ClientCallback<?> callback) {
+    public void postBatchData(ByteString signerId, int batchId, List<BatchData> batchDataList,
-        // TODO: write this
+                              int startPosition, ClientCallback<Boolean> callback) {
+
+        postBatchData(signerId.toByteArray(), batchId, batchDataList, startPosition, callback);
+
+    }
+
+    @Override
+    public void postBatchData(ByteString signerId, int batchId, List<BatchData> batchDataList, ClientCallback<Boolean> callback) {
+
+        postBatchData(signerId, batchId, batchDataList, 0, callback);
+
+    }
+
+    @Override
+    public void closeBatch(CloseBatchMessage closeBatchMessage, ClientCallback<Boolean> callback) {
+
+        // Create job
+        MultiServerCloseBatchWorker worker =
+                new MultiServerCloseBatchWorker(clients, minAbsoluteRedundancy, closeBatchMessage, POST_MESSAGE_RETRY_NUM, callback);
+
+        // Submit job
+        executorService.submit(worker);
+
     }
 
     /**
@@ -158,8 +206,15 @@ public class ThreadedBulletinBoardClient extends SimpleBulletinBoardClient imple
     }
 
     @Override
-    public void readBatch(byte[] signerId, int batchId, ClientCallback<CompleteBatch> callback) {
+    public void readBatch(BatchSpecificationMessage batchSpecificationMessage, ClientCallback<CompleteBatch> callback) {
-        // TODO: Implement
+
+        // Create job
+        MultiServerReadBatchWorker worker =
+                new MultiServerReadBatchWorker(clients, minAbsoluteRedundancy, batchSpecificationMessage, READ_MESSAGES_RETRY_NUM, callback);
+
+        // Submit job
+        executorService.submit(worker);
+
     }
 
     @Override

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/MultiServerPostBatchWorker.java

@@ -1,7 +0,0 @@
-package meerkat.bulletinboard.workers;
-
-/**
- * Created by Arbel Deutsch Peled on 27-Dec-15.
- */
-public class MultiServerPostBatchWorker {
-}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerBeginBatchWorker.java

@@ -0,0 +1,28 @@
+package meerkat.bulletinboard.workers.multiserver;
+
+import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
+import meerkat.bulletinboard.SingleServerBulletinBoardClient;
+import meerkat.protobuf.BulletinBoardAPI.BeginBatchMessage;
+
+import java.util.List;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ */
+public class MultiServerBeginBatchWorker extends MultiServerGenericPostWorker<BeginBatchMessage> {
+
+    public MultiServerBeginBatchWorker(List<SingleServerBulletinBoardClient> clients,
+                                       int minServers, BeginBatchMessage payload, int maxRetry,
+                                       ClientCallback<Boolean> clientCallback) {
+
+        super(clients, minServers, payload, maxRetry, clientCallback);
+
+    }
+
+    @Override
+    protected void doPost(SingleServerBulletinBoardClient client, BeginBatchMessage payload) {
+        client.beginBatch(payload, this);
+    }
+
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerCloseBatchWorker.java

@@ -0,0 +1,28 @@
+package meerkat.bulletinboard.workers.multiserver;
+
+import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
+import meerkat.bulletinboard.SingleServerBulletinBoardClient;
+import meerkat.protobuf.BulletinBoardAPI.CloseBatchMessage;
+
+import java.util.List;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ */
+public class MultiServerCloseBatchWorker extends MultiServerGenericPostWorker<CloseBatchMessage> {
+
+    public MultiServerCloseBatchWorker(List<SingleServerBulletinBoardClient> clients,
+                                       int minServers, CloseBatchMessage payload, int maxRetry,
+                                       ClientCallback<Boolean> clientCallback) {
+
+        super(clients, minServers, payload, maxRetry, clientCallback);
+
+    }
+
+    @Override
+    protected void doPost(SingleServerBulletinBoardClient client, CloseBatchMessage payload) {
+        client.closeBatch(payload, this);
+    }
+
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerGenericPostWorker.java

@@ -1,10 +1,9 @@
-package meerkat.bulletinboard.workers;
+package meerkat.bulletinboard.workers.multiserver;
 
 import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
 import meerkat.bulletinboard.MultiServerWorker;
 import meerkat.bulletinboard.SingleServerBulletinBoardClient;
 import meerkat.comm.CommunicationException;
-import meerkat.protobuf.BulletinBoardAPI.*;
 
 import javax.ws.rs.client.WebTarget;
 import javax.ws.rs.core.Response;
@@ -14,16 +13,18 @@ import java.util.List;
 /**
  * Created by Arbel Deutsch Peled on 27-Dec-15.
  */
-public class MultiServerPostMessageWorker extends MultiServerWorker<BulletinBoardMessage, Boolean> {
+public abstract class MultiServerGenericPostWorker<T> extends MultiServerWorker<T, Boolean> {
 
-    public MultiServerPostMessageWorker(List<SingleServerBulletinBoardClient> clients,
+    public MultiServerGenericPostWorker(List<SingleServerBulletinBoardClient> clients,
-                                        int minServers, BulletinBoardMessage payload, int maxRetry,
+                                        int minServers, T payload, int maxRetry,
                                         ClientCallback<Boolean> clientCallback) {
 
         super(clients, minServers, payload, maxRetry, clientCallback);
 
     }
 
+    protected abstract void doPost(SingleServerBulletinBoardClient client, T payload);
+
     /**
      * This method carries out the actual communication with the servers via HTTP Post
      * It accesses the servers one by one and tries to post the payload to each in turn
@@ -48,7 +49,7 @@ public class MultiServerPostMessageWorker extends MultiServerWorker<BulletinBoar
             // Send request to Server
             SingleServerBulletinBoardClient client = clientIterator.next();
 
-            client.postMessage(payload, this);
+            doPost(client, payload);
 
         }
 

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerGenericReadWorker.java

@@ -1,10 +1,9 @@
-package meerkat.bulletinboard.workers;
+package meerkat.bulletinboard.workers.multiserver;
 
 import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
 import meerkat.bulletinboard.MultiServerWorker;
 import meerkat.bulletinboard.SingleServerBulletinBoardClient;
 import meerkat.comm.CommunicationException;
-import meerkat.protobuf.BulletinBoardAPI.*;
 
 import java.util.Iterator;
 import java.util.List;
@@ -13,13 +12,13 @@ import java.util.List;
 /**
  * Created by Arbel Deutsch Peled on 27-Dec-15.
  */
-public class MultiServerReadMessagesWorker extends MultiServerWorker<MessageFilterList,List<BulletinBoardMessage>>{
+public abstract class MultiServerGenericReadWorker<IN, OUT> extends MultiServerWorker<IN, OUT>{
 
-    private Iterator<SingleServerBulletinBoardClient> clientIterator;
+    protected Iterator<SingleServerBulletinBoardClient> clientIterator;
 
-    public MultiServerReadMessagesWorker(List<SingleServerBulletinBoardClient> clients,
+    public MultiServerGenericReadWorker(List<SingleServerBulletinBoardClient> clients,
-                                        int minServers, MessageFilterList payload, int maxRetry,
+                                        int minServers, IN payload, int maxRetry,
-                                        ClientCallback<List<BulletinBoardMessage>> clientCallback) {
+                                        ClientCallback<OUT> clientCallback) {
 
         super(clients, true, minServers, payload, maxRetry, clientCallback); // Shuffle clients on creation to balance load
 
@@ -27,6 +26,8 @@ public class MultiServerReadMessagesWorker extends MultiServerWorker<MessageFilt
 
     }
 
+    protected abstract void doRead(IN payload, SingleServerBulletinBoardClient client);
+
     /**
      * This method carries out the actual communication with the servers via HTTP Post
      * It accesses the servers in a random order until one answers it
@@ -44,7 +45,7 @@ public class MultiServerReadMessagesWorker extends MultiServerWorker<MessageFilt
             SingleServerBulletinBoardClient client = clientIterator.next();
 
             // Retrieve answer
-            client.readMessages(payload,this);
+            doRead(payload, client);
 
         } else {
             fail(new CommunicationException("Could not contact any server"));
@@ -53,7 +54,7 @@ public class MultiServerReadMessagesWorker extends MultiServerWorker<MessageFilt
     }
 
     @Override
-    public void handleCallback(List<BulletinBoardMessage> msg) {
+    public void handleCallback(OUT msg) {
         succeed(msg);
     }
 

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerGetRedundancyWorker.java

@@ -1,4 +1,4 @@
-package meerkat.bulletinboard.workers;
+package meerkat.bulletinboard.workers.multiserver;
 
 import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
 import meerkat.bulletinboard.MultiServerWorker;

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerPostBatchDataWorker.java

@@ -0,0 +1,28 @@
+package meerkat.bulletinboard.workers.multiserver;
+
+import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
+import meerkat.bulletinboard.SingleServerBulletinBoardClient;
+import meerkat.bulletinboard.BatchDataContainer;
+
+import java.util.List;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ */
+public class MultiServerPostBatchDataWorker extends MultiServerGenericPostWorker<BatchDataContainer> {
+
+    public MultiServerPostBatchDataWorker(List<SingleServerBulletinBoardClient> clients,
+                                          int minServers, BatchDataContainer payload, int maxRetry,
+                                          ClientCallback<Boolean> clientCallback) {
+
+        super(clients, minServers, payload, maxRetry, clientCallback);
+
+    }
+
+    @Override
+    protected void doPost(SingleServerBulletinBoardClient client, BatchDataContainer payload) {
+        client.postBatchData(payload.signerId, payload.batchId, payload.batchDataList, payload.startPosition, this);
+    }
+
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerPostBatchWorker.java

@@ -0,0 +1,28 @@
+package meerkat.bulletinboard.workers.multiserver;
+
+import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
+import meerkat.bulletinboard.CompleteBatch;
+import meerkat.bulletinboard.SingleServerBulletinBoardClient;
+
+import java.util.List;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ */
+public class MultiServerPostBatchWorker extends MultiServerGenericPostWorker<CompleteBatch> {
+
+    public MultiServerPostBatchWorker(List<SingleServerBulletinBoardClient> clients,
+                                      int minServers, CompleteBatch payload, int maxRetry,
+                                      ClientCallback<Boolean> clientCallback) {
+
+        super(clients, minServers, payload, maxRetry, clientCallback);
+
+    }
+
+    @Override
+    protected void doPost(SingleServerBulletinBoardClient client, CompleteBatch payload) {
+        client.postBatch(payload, this);
+    }
+
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerPostMessageWorker.java

@@ -0,0 +1,28 @@
+package meerkat.bulletinboard.workers.multiserver;
+
+import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
+import meerkat.bulletinboard.SingleServerBulletinBoardClient;
+import meerkat.protobuf.BulletinBoardAPI.*;
+
+import java.util.List;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ */
+public class MultiServerPostMessageWorker extends MultiServerGenericPostWorker<BulletinBoardMessage> {
+
+    public MultiServerPostMessageWorker(List<SingleServerBulletinBoardClient> clients,
+                                        int minServers, BulletinBoardMessage payload, int maxRetry,
+                                        ClientCallback<Boolean> clientCallback) {
+
+        super(clients, minServers, payload, maxRetry, clientCallback);
+
+    }
+
+    @Override
+    protected void doPost(SingleServerBulletinBoardClient client, BulletinBoardMessage payload) {
+        client.postMessage(payload, this);
+    }
+
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerReadBatchWorker.java

@@ -0,0 +1,30 @@
+package meerkat.bulletinboard.workers.multiserver;
+
+import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
+import meerkat.bulletinboard.CompleteBatch;
+import meerkat.bulletinboard.SingleServerBulletinBoardClient;
+import meerkat.protobuf.BulletinBoardAPI.BatchSpecificationMessage;
+
+import java.util.List;
+
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ */
+public class MultiServerReadBatchWorker extends MultiServerGenericReadWorker<BatchSpecificationMessage, CompleteBatch> {
+
+    public MultiServerReadBatchWorker(List<SingleServerBulletinBoardClient> clients,
+                                      int minServers, BatchSpecificationMessage payload, int maxRetry,
+                                      ClientCallback<CompleteBatch> clientCallback) {
+
+        super(clients, minServers, payload, maxRetry, clientCallback);
+
+    }
+
+    @Override
+    protected void doRead(BatchSpecificationMessage payload, SingleServerBulletinBoardClient client) {
+        client.readBatch(payload, this);
+    }
+
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/multiserver/MultiServerReadMessagesWorker.java

@@ -0,0 +1,29 @@
+package meerkat.bulletinboard.workers.multiserver;
+
+import meerkat.bulletinboard.AsyncBulletinBoardClient.ClientCallback;
+import meerkat.bulletinboard.SingleServerBulletinBoardClient;
+import meerkat.protobuf.BulletinBoardAPI.*;
+
+import java.util.List;
+
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ */
+public class MultiServerReadMessagesWorker extends MultiServerGenericReadWorker<MessageFilterList,List<BulletinBoardMessage>>{
+
+    public MultiServerReadMessagesWorker(List<SingleServerBulletinBoardClient> clients,
+                                        int minServers, MessageFilterList payload, int maxRetry,
+                                        ClientCallback<List<BulletinBoardMessage>> clientCallback) {
+
+        super(clients, minServers, payload, maxRetry, clientCallback);
+
+    }
+
+    @Override
+    protected void doRead(MessageFilterList payload, SingleServerBulletinBoardClient client) {
+        client.readMessages(payload, this);
+    }
+
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/singleserver/SingleServerBeginBatchWorker.java

@@ -0,0 +1,17 @@
+package meerkat.bulletinboard.workers.singleserver;
+
+import meerkat.protobuf.BulletinBoardAPI.BeginBatchMessage;
+
+import static meerkat.bulletinboard.BulletinBoardConstants.BEGIN_BATCH_PATH;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ * Tries to contact server once and perform a post operation
+ */
+public class SingleServerBeginBatchWorker extends SingleServerGenericPostWorker<BeginBatchMessage> {
+
+    public SingleServerBeginBatchWorker(String serverAddress, BeginBatchMessage payload, int maxRetry) {
+        super(serverAddress, BEGIN_BATCH_PATH, payload, maxRetry);
+    }
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/singleserver/SingleServerCloseBatchWorker.java

@@ -0,0 +1,17 @@
+package meerkat.bulletinboard.workers.singleserver;
+
+import meerkat.protobuf.BulletinBoardAPI.CloseBatchMessage;
+
+import static meerkat.bulletinboard.BulletinBoardConstants.CLOSE_BATCH_PATH;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ * Tries to contact server once and perform a close batch operation
+ */
+public class SingleServerCloseBatchWorker extends SingleServerGenericPostWorker<CloseBatchMessage> {
+
+    public SingleServerCloseBatchWorker(String serverAddress, CloseBatchMessage payload, int maxRetry) {
+        super(serverAddress, CLOSE_BATCH_PATH, payload, maxRetry);
+    }
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/singleserver/SingleServerGenericPostWorker.java

@@ -1,9 +1,8 @@
-package meerkat.bulletinboard.workers;
+package meerkat.bulletinboard.workers.singleserver;
 
 import meerkat.bulletinboard.SingleServerWorker;
 import meerkat.comm.CommunicationException;
 import meerkat.protobuf.BulletinBoardAPI.BoolMsg;
-import meerkat.protobuf.BulletinBoardAPI.BulletinBoardMessage;
 import meerkat.rest.Constants;
 
 import javax.ws.rs.ProcessingException;
@@ -13,16 +12,18 @@ import javax.ws.rs.client.WebTarget;
 import javax.ws.rs.core.Response;
 
 import static meerkat.bulletinboard.BulletinBoardConstants.BULLETIN_BOARD_SERVER_PATH;
-import static meerkat.bulletinboard.BulletinBoardConstants.POST_MESSAGE_PATH;
 
 /**
  * Created by Arbel Deutsch Peled on 27-Dec-15.
  * Tries to contact server once and perform a post operation
  */
-public class SingleServerPostMessageWorker extends SingleServerWorker<BulletinBoardMessage, Boolean> {
+public class SingleServerGenericPostWorker<T> extends SingleServerWorker<T, Boolean> {
 
-    public SingleServerPostMessageWorker(String serverAddress, BulletinBoardMessage payload, int maxRetry) {
+    private String subPath;
+
+    public SingleServerGenericPostWorker(String serverAddress, String subPath, T payload, int maxRetry) {
         super(serverAddress, payload, maxRetry);
+        this.subPath = subPath;
     }
 
     /**
@@ -30,13 +31,13 @@ public class SingleServerPostMessageWorker extends SingleServerWorker<BulletinBo
      * It accesses the server and tries to post the payload to it
      * Successful post to a server results
      * @return TRUE if the operation is successful
-     * @throws CommunicationException if the operation is unseccessful
+     * @throws CommunicationException if the operation is unsuccessful
      */
     public Boolean call() throws CommunicationException{
 
         Client client = clientLocal.get();
 
-        WebTarget webTarget = client.target(serverAddress).path(BULLETIN_BOARD_SERVER_PATH).path(POST_MESSAGE_PATH);;
+        WebTarget webTarget = client.target(serverAddress).path(BULLETIN_BOARD_SERVER_PATH).path(subPath);;
         Response response = webTarget.request(Constants.MEDIATYPE_PROTOBUF).post(
                 Entity.entity(payload, Constants.MEDIATYPE_PROTOBUF));
 

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/singleserver/SingleServerGetRedundancyWorker.java

@@ -1,4 +1,4 @@
-package meerkat.bulletinboard.workers;
+package meerkat.bulletinboard.workers.singleserver;
 
 import meerkat.bulletinboard.SingleServerWorker;
 import meerkat.comm.CommunicationException;

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/singleserver/SingleServerPostBatchWorker.java

@@ -0,0 +1,17 @@
+package meerkat.bulletinboard.workers.singleserver;
+
+import meerkat.protobuf.BulletinBoardAPI.BatchMessage;
+
+import static meerkat.bulletinboard.BulletinBoardConstants.POST_BATCH_PATH;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ * Tries to contact server once and perform a post batch operation
+ */
+public class SingleServerPostBatchWorker extends SingleServerGenericPostWorker<BatchMessage> {
+
+    public SingleServerPostBatchWorker(String serverAddress, BatchMessage payload, int maxRetry) {
+        super(serverAddress, POST_BATCH_PATH, payload, maxRetry);
+    }
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/singleserver/SingleServerPostMessageWorker.java

@@ -0,0 +1,17 @@
+package meerkat.bulletinboard.workers.singleserver;
+
+import meerkat.protobuf.BulletinBoardAPI.BulletinBoardMessage;
+
+import static meerkat.bulletinboard.BulletinBoardConstants.POST_MESSAGE_PATH;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ * Tries to contact server once and perform a post operation
+ */
+public class SingleServerPostMessageWorker extends SingleServerGenericPostWorker<BulletinBoardMessage> {
+
+    public SingleServerPostMessageWorker(String serverAddress, BulletinBoardMessage payload, int maxRetry) {
+        super(serverAddress, POST_MESSAGE_PATH, payload, maxRetry);
+    }
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/singleserver/SingleServerReadBatchWorker.java

@@ -0,0 +1,119 @@
+package meerkat.bulletinboard.workers.singleserver;
+
+import meerkat.bulletinboard.CompleteBatch;
+import meerkat.bulletinboard.SingleServerWorker;
+import meerkat.comm.CommunicationException;
+import meerkat.protobuf.BulletinBoardAPI.*;
+import meerkat.rest.Constants;
+
+import javax.ws.rs.ProcessingException;
+import javax.ws.rs.client.Client;
+import javax.ws.rs.client.Entity;
+import javax.ws.rs.client.WebTarget;
+import javax.ws.rs.core.GenericType;
+import javax.ws.rs.core.Response;
+import java.util.List;
+
+import static meerkat.bulletinboard.BulletinBoardConstants.BULLETIN_BOARD_SERVER_PATH;
+import static meerkat.bulletinboard.BulletinBoardConstants.READ_MESSAGES_PATH;
+import static meerkat.bulletinboard.BulletinBoardConstants.READ_BATCH_PATH;
+
+import static meerkat.bulletinboard.BulletinBoardConstants.BATCH_ID_TAG_PREFIX;
+
+/**
+ * Created by Arbel Deutsch Peled on 27-Dec-15.
+ */
+public class SingleServerReadBatchWorker extends SingleServerWorker<BatchSpecificationMessage, CompleteBatch> {
+
+    public SingleServerReadBatchWorker(String serverAddress, BatchSpecificationMessage payload, int maxRetry) {
+        super(serverAddress, payload, maxRetry);
+    }
+
+    /**
+     * This method carries out the actual communication with the server via HTTP Post
+     * Upon successful retrieval from the server the method returns the received values
+     * @return the complete batch as read from the server
+     * @throws CommunicationException if the server's response is invalid
+     */
+    public CompleteBatch call() throws CommunicationException{
+
+        CompleteBatch completeBatch = new CompleteBatch();
+
+        Client client = clientLocal.get();
+
+        WebTarget webTarget;
+        Response response;
+
+        // Set filters for the batch message metadata retrieval
+
+        MessageFilterList messageFilterList = MessageFilterList.newBuilder()
+                .addFilter(MessageFilter.newBuilder()
+                        .setType(FilterType.TAG)
+                        .setTag(BATCH_ID_TAG_PREFIX + String.valueOf(payload.getBatchId()))
+                        .build())
+                .addFilter(MessageFilter.newBuilder()
+                        .setType(FilterType.SIGNER_ID)
+                        .setId(payload.getSignerId())
+                        .build())
+                .build();
+
+        // Send request to Server
+
+        webTarget = client.target(serverAddress).path(BULLETIN_BOARD_SERVER_PATH).path(READ_MESSAGES_PATH);
+        response = webTarget.request(Constants.MEDIATYPE_PROTOBUF).post(
+                Entity.entity(messageFilterList, Constants.MEDIATYPE_PROTOBUF));
+
+        // Retrieve answer
+
+        try {
+
+            // If a BulletinBoardMessageList is returned: the read was successful
+            BulletinBoardMessage metadata = response.readEntity(BulletinBoardMessageList.class).getMessage(0);
+
+            completeBatch.setBeginBatchMessage(BeginBatchMessage.newBuilder()
+                    .setSignerId(payload.getSignerId())
+                    .setBatchId(payload.getBatchId())
+                    .addAllTag(metadata.getMsg().getTagList())
+                    .build());
+
+            completeBatch.setSignature(metadata.getSig(0));
+
+        } catch (ProcessingException | IllegalStateException e) {
+
+            // Read failed
+            throw new CommunicationException("Could not contact the server");
+
+        }
+        finally {
+            response.close();
+        }
+
+        // Get the batch data
+
+        webTarget = client.target(serverAddress).path(BULLETIN_BOARD_SERVER_PATH).path(READ_BATCH_PATH);
+        response = webTarget.request(Constants.MEDIATYPE_PROTOBUF).post(
+                Entity.entity(payload, Constants.MEDIATYPE_PROTOBUF));
+
+        // Retrieve answer
+
+        try {
+
+            // If a List of BatchData is returned: the read was successful
+
+            completeBatch.appendBatchData(response.readEntity(new GenericType<List<BatchData>>(){}));
+
+        } catch (ProcessingException | IllegalStateException e) {
+
+            // Read failed
+            throw new CommunicationException("Could not contact the server");
+
+        }
+        finally {
+            response.close();
+        }
+
+        return completeBatch;
+
+    }
+
+}

bulletin-board-client/src/main/java/meerkat/bulletinboard/workers/singleserver/SingleServerReadMessagesWorker.java

@@ -1,4 +1,4 @@
-package meerkat.bulletinboard.workers;
+package meerkat.bulletinboard.workers.singleserver;
 
 import meerkat.bulletinboard.SingleServerWorker;
 import meerkat.comm.CommunicationException;

bulletin-board-server/src/main/java/meerkat/bulletinboard/webapp/BulletinBoardWebApp.java

@@ -141,6 +141,10 @@ public class BulletinBoardWebApp implements BulletinBoardServer, ServletContextL
 		}
 	}
 
+	@Path(READ_BATCH_PATH)
+	@POST
+	@Consumes(MEDIATYPE_PROTOBUF)
+	@Produces(MEDIATYPE_PROTOBUF)
 	@Override
 	public List<BatchData> readBatch(BatchSpecificationMessage message) {
 		try {

meerkat-common/src/main/java/meerkat/bulletinboard/AsyncBulletinBoardClient.java

@@ -1,7 +1,7 @@
 package meerkat.bulletinboard;
 
+import com.google.protobuf.ByteString;
 import meerkat.protobuf.BulletinBoardAPI.*;
-import meerkat.protobuf.Crypto.Signature;
 
 import java.util.List;
 
@@ -37,36 +37,47 @@ public interface AsyncBulletinBoardClient extends BulletinBoardClient {
 
     /**
      * This message informs the server about the existence of a new batch message and supplies it with the tags associated with it
-     * @param signerId is the canonical form for the ID of the sender of this batch
+     * @param beginBatchMessage contains the data required to begin the batch
-     * @param batchId is a unique (per signer) ID for this batch
+     * @param callback is a callback function class for handling results of the operation
-     * @param tagList is a list of tags that belong to the batch message
      */
-    public void beginBatch(byte[] signerId, int batchId, List<String> tagList, ClientCallback<Boolean> callback);
+    public void beginBatch(BeginBatchMessage beginBatchMessage, ClientCallback<Boolean> callback);
 
     /**
      * This method posts batch data into an (assumed to be open) batch
      * It does not close the batch
      * @param signerId is the canonical form for the ID of the sender of this batch
      * @param batchId is a unique (per signer) ID for this batch
-     * @param batchDataList is the (canonically ordered) list of data comprising the entire batch message (not just the portion to be written)
+     * @param batchDataList is the (canonically ordered) list of data comprising the portion of the batch to be posted
      * @param startPosition is the location (in the batch) of the first entry in batchDataList
      *                      (optionally used to continue interrupted post operations)
+     *                      The first position in the batch is position 0
      * @param callback is a callback function class for handling results of the operation
      */
     public void postBatchData(byte[] signerId, int batchId, List<BatchData> batchDataList,
-                                   int startPosition, ClientCallback<Boolean> callback);
+                              int startPosition, ClientCallback<Boolean> callback);
 
     /**
-     * Overloading of the postBatchData method in which startPosition is set to the default value 0
+     * Overloading of the postBatchData method which starts at the first position in the batch
      */
     public void postBatchData(byte[] signerId, int batchId, List<BatchData> batchDataList, ClientCallback<Boolean> callback);
 
+    /**
+     * Overloading of the postBatchData method which uses ByteString
+     */
+    public void postBatchData(ByteString signerId, int batchId, List<BatchData> batchDataList,
+                              int startPosition, ClientCallback<Boolean> callback);
+
+    /**
+     * Overloading of the postBatchData method which uses ByteString and starts at the first position in the batch
+     */
+    public void postBatchData(ByteString signerId, int batchId, List<BatchData> batchDataList, ClientCallback<Boolean> callback);
+
     /**
      * Attempts to close a batch message
      * @param closeBatchMessage contains the data required to close the batch
      * @param callback is a callback function class for handling results of the operation
      */
-    public void closeBatch(CloseBatchMessage closeBatchMessage, ClientCallback<?> callback);
+    public void closeBatch(CloseBatchMessage closeBatchMessage, ClientCallback<Boolean> callback);
 
     /**
      * Check how "safe" a given message is in an asynchronous manner
@@ -88,11 +99,10 @@ public interface AsyncBulletinBoardClient extends BulletinBoardClient {
 
     /**
      * Read a given batch message from the bulletin board
-     * @param signerId is the ID of the signer (sender) of the batch message
+     * @param batchSpecificationMessage contains the data required to specify a single batch instance
-     * @param batchId is the unique (per signer) ID of the batch
      * @param callback is a callback class for handling the result of the operation
      */
-    public void readBatch(byte[] signerId, int batchId, ClientCallback<CompleteBatch> callback);
+    public void readBatch(BatchSpecificationMessage batchSpecificationMessage, ClientCallback<CompleteBatch> callback);
 
     /**
      * Subscribes to a notifier that will return any new messages on the server that match the given filters

meerkat-common/src/main/java/meerkat/bulletinboard/BulletinBoardConstants.java

@@ -9,6 +9,7 @@ public interface BulletinBoardConstants {
 
     public static final String BULLETIN_BOARD_SERVER_PATH = "/bbserver";
     public static final String READ_MESSAGES_PATH = "/readmessages";
+    public static final String READ_BATCH_PATH = "/readbatch";
     public static final String POST_MESSAGE_PATH = "/postmessage";
     public static final String BEGIN_BATCH_PATH = "/beginbatch";
     public static final String POST_BATCH_PATH = "/postbatch";
@@ -17,6 +18,6 @@ public interface BulletinBoardConstants {
     // Other Constants
 
     public static final String BATCH_TAG = "@BATCH";
-    public static final String BATCH_ID_TAG_PREFIX = "#";
+    public static final String BATCH_ID_TAG_PREFIX = "BATCHID#";
 
 }

meerkat-common/src/main/java/meerkat/bulletinboard/GenericBatchDigest.java

@@ -2,7 +2,7 @@ package meerkat.bulletinboard;
 
 import com.google.protobuf.Message;
 import meerkat.crypto.Digest;
-import meerkat.protobuf.BulletinBoardAPI.BeginBatchMessage;
+import meerkat.protobuf.BulletinBoardAPI.MessageID;
 import meerkat.protobuf.BulletinBoardAPI.BatchData;
 
 import java.util.List;
@@ -36,6 +36,11 @@ public class GenericBatchDigest implements BatchDigest{
         return digest.digest();
     }
 
+    @Override
+    public MessageID digestAsMessageID() {
+        return digest.digestAsMessageID();
+    }
+
     @Override
     public void update(Message msg) {
         digest.update(msg);

meerkat-common/src/main/java/meerkat/crypto/Digest.java

@@ -1,6 +1,7 @@
 package meerkat.crypto;
 
 import com.google.protobuf.Message;
+import meerkat.protobuf.BulletinBoardAPI.MessageID;
 
 import java.security.MessageDigest;
 
@@ -15,6 +16,12 @@ public interface Digest {
      */
     public byte[] digest();
 
+    /**
+     * Completes the hash computation and returns a MessageID Protobuf as output
+     * @return
+     */
+    public MessageID digestAsMessageID();
+
     /**
      * Updates the digest using the specified message (in serialized wire form)
      *

meerkat-common/src/main/java/meerkat/crypto/concrete/SHA256Digest.java

@@ -3,6 +3,7 @@ package meerkat.crypto.concrete;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.Message;
 import meerkat.crypto.Digest;
+import meerkat.protobuf.BulletinBoardAPI.MessageID;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -60,6 +61,11 @@ public class SHA256Digest implements Digest {
         return hash.digest();
     }
 
+    @Override
+    public MessageID digestAsMessageID() {
+        return MessageID.newBuilder().setID(ByteString.copyFrom(digest())).build();
+    }
+
     @Override
     public void update(Message msg) {