Working client-side Batch changes

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

@@ -3,9 +3,7 @@ package meerkat.bulletinboard;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.protobuf.Timestamp;
 import meerkat.comm.CommunicationException;
-import meerkat.protobuf.BulletinBoardAPI;
 import meerkat.protobuf.BulletinBoardAPI.*;
-import meerkat.protobuf.Comm;
 import meerkat.protobuf.Crypto.Signature;
 import meerkat.protobuf.Voting.*;
 
@@ -267,9 +265,9 @@ public class CachedBulletinBoardClient implements SubscriptionBulletinBoardClien
     }
 
     @Override
-    public void readBatch(final MessageID msgID, final FutureCallback<BulletinBoardMessage> callback) {
+    public void readMessage(final MessageID msgID, final FutureCallback<BulletinBoardMessage> callback) {
 
-        localClient.readBatch(msgID, new FutureCallback<BulletinBoardMessage>() {
+        localClient.readMessage(msgID, new FutureCallback<BulletinBoardMessage>() {
 
             @Override
             public void onSuccess(BulletinBoardMessage result) {
@@ -282,7 +280,7 @@ public class CachedBulletinBoardClient implements SubscriptionBulletinBoardClien
 
                 // Read from local unsuccessful: try to read from remote
 
-                remoteClient.readBatch(msgID, new FutureCallback<BulletinBoardMessage>() {
+                remoteClient.readMessage(msgID, new FutureCallback<BulletinBoardMessage>() {
 
                     @Override
                     public void onSuccess(BulletinBoardMessage result) {
@@ -398,17 +396,17 @@ public class CachedBulletinBoardClient implements SubscriptionBulletinBoardClien
     }
 
     @Override
-    public BulletinBoardMessage readBatch(MessageID msgID) throws CommunicationException {
+    public BulletinBoardMessage readMessage(MessageID msgID) throws CommunicationException {
 
         BulletinBoardMessage result = null;
         try {
-            result = localClient.readBatch(msgID);
+            result = localClient.readMessage(msgID);
         } catch (CommunicationException e) {
             //TODO: log
         }
 
         if (result == null){
-            result = remoteClient.readBatch(msgID);
+            result = remoteClient.readMessage(msgID);
 
             if (result != null){
                 localClient.postMessage(result);

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

@@ -183,6 +183,8 @@ public class LocalBulletinBoardClient implements DeletableSubscriptionBulletinBo
 
             }
 
+            batchId.setLength(i);
+
             return true;
 
         }
@@ -244,6 +246,7 @@ public class LocalBulletinBoardClient implements DeletableSubscriptionBulletinBo
 
         CloseBatchMessage closeBatchMessage = CloseBatchMessage.newBuilder()
                 .setBatchId(identifier.getBatchId().getValue())
+                .setBatchLength(identifier.getLength())
                 .setTimestamp(timestamp)
                 .addAllSig(signatures)
                 .build();
@@ -438,7 +441,7 @@ public class LocalBulletinBoardClient implements DeletableSubscriptionBulletinBo
         @Override
         public BulletinBoardMessage call() throws Exception {
 
-            // Read message stub
+            // Read message (mat be a stub)
 
             MessageFilterList filterList = MessageFilterList.newBuilder()
                     .addFilter(MessageFilter.newBuilder()
@@ -451,10 +454,12 @@ public class LocalBulletinBoardClient implements DeletableSubscriptionBulletinBo
             List<BulletinBoardMessage> bulletinBoardMessages = messageReader.call();
 
             if (bulletinBoardMessages.size() <= 0) {
-                throw new NotFoundException("Batch does not exist");
+                throw new NotFoundException("Message does not exist");
             }
 
-            BulletinBoardMessage stub = bulletinBoardMessages.get(0);
+            BulletinBoardMessage msg = bulletinBoardMessages.get(0);
+
+            if (msg.getMsg().getDataTypeCase() == UnsignedBulletinBoardMessage.DataTypeCase.MSGID) {
 
                 // Read data
 
@@ -463,7 +468,11 @@ public class LocalBulletinBoardClient implements DeletableSubscriptionBulletinBo
 
                 // Combine and return
 
-            return BulletinBoardUtils.gatherBatch(stub, batchChunkList);
+                return BulletinBoardUtils.gatherBatch(msg, batchChunkList);
+
+            } else {
+                return msg;
+            }
 
         }
 
@@ -493,7 +502,7 @@ public class LocalBulletinBoardClient implements DeletableSubscriptionBulletinBo
     }
 
     @Override
-    public void readBatch(MessageID msgID, FutureCallback<BulletinBoardMessage> callback) {
+    public void readMessage(MessageID msgID, FutureCallback<BulletinBoardMessage> callback) {
         Futures.addCallback(executorService.submit(new CompleteBatchReader(msgID)), callback);
     }
 
@@ -591,7 +600,7 @@ public class LocalBulletinBoardClient implements DeletableSubscriptionBulletinBo
     }
 
     @Override
-    public BulletinBoardMessage readBatch(MessageID msgID) throws CommunicationException {
+    public BulletinBoardMessage readMessage(MessageID msgID) throws CommunicationException {
 
         MessageFilterList filterList = MessageFilterList.newBuilder()
                 .addFilter(MessageFilter.newBuilder()
@@ -617,20 +626,14 @@ public class LocalBulletinBoardClient implements DeletableSubscriptionBulletinBo
             throw new IllegalArgumentException("Message is not a stub and does not contain the required message ID");
         }
 
-        MessageID msgID = MessageID.newBuilder().setID(stub.getMsg().getMsgId()).build();
+        BatchDataCombiner combiner = new BatchDataCombiner(stub);
-
-        BatchDataReader batchDataReader = new BatchDataReader(msgID);
-
-        List<BatchChunk> batchChunkList = null;
 
         try {
-            batchChunkList = batchDataReader.call();
+            return combiner.call();
         } catch (Exception e) {
             throw new CommunicationException(e.getCause() + " " + e.getMessage());
         }
 
-        return BulletinBoardUtils.gatherBatch(stub, batchChunkList);
-
     }
 
     @Override

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

@@ -224,7 +224,7 @@ public class SimpleBulletinBoardClient implements BulletinBoardClient{
     }
 
     @Override
-    public BulletinBoardMessage readBatch(MessageID msgID) throws CommunicationException {
+    public BulletinBoardMessage readMessage(MessageID msgID) throws CommunicationException {
 
         MessageFilterList filterList = MessageFilterList.newBuilder()
                 .addFilter(MessageFilter.newBuilder()

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

@@ -36,75 +36,6 @@ public class SimpleBulletinBoardSynchronizer implements BulletinBoardSynchronize
 
     private Semaphore semaphore;
 
-    /**
-     * This class is a callback that deletes a message if it has been successfully posted
-     * It also calls a stored callback
-     */
-    private class MessageDeleteCallback implements FutureCallback<Boolean> {
-
-        private final long entryNum;
-        private final FutureCallback<Void> callback;
-
-        public MessageDeleteCallback(long entryNum, FutureCallback<Void> callback) {
-            this.entryNum = entryNum;
-            this.callback = callback;
-        }
-
-        @Override
-        public void onSuccess(Boolean result) {
-            // Success: delete from database
-            localClient.deleteMessage(entryNum, null);
-            callback.onSuccess(null);
-        }
-
-        @Override
-        public void onFailure(Throwable t) {
-            callback.onFailure(t);
-        }
-
-    }
-
-    /**
-     * This class aggregates the results from all of the post operations
-     * If any post has failed: it changes the sync status to SERVER_ERROR
-     * It also notifies the main sync loop when all uploads are finished
-     */
-    private class SyncStatusUpdateCallback implements FutureCallback<Void> {
-
-        private int count;
-        private boolean errorEncountered;
-
-        public SyncStatusUpdateCallback(int count) {
-            this.count = count;
-            this.errorEncountered = false;
-        }
-
-        private void handleStatusUpdate() {
-            count--;
-            if (count <= 0) {
-
-                if (errorEncountered)
-                    updateSyncStatus(SyncStatus.SERVER_ERROR);
-
-                // Upload is done: wake up the synchronizer loop
-                semaphore.release();
-
-            }
-        }
-
-        @Override
-        public void onSuccess(Void result) {
-            handleStatusUpdate();
-        }
-
-        @Override
-        public void onFailure(Throwable t) {
-            errorEncountered = true;
-            handleStatusUpdate();
-        }
-
-    }
-
     private class SyncCallback implements FutureCallback<List<BulletinBoardMessage>> {
 
         @Override
@@ -122,8 +53,6 @@ public class SimpleBulletinBoardSynchronizer implements BulletinBoardSynchronize
 
             // Handle upload and status change
 
-            SyncStatusUpdateCallback syncStatusUpdateCallback = new SyncStatusUpdateCallback(result.size());
-
             SyncStatus newStatus = SyncStatus.PENDING;
 
             if (result.size() == 0) {
@@ -143,13 +72,17 @@ public class SimpleBulletinBoardSynchronizer implements BulletinBoardSynchronize
 
                             BulletinBoardMessage completeMsg = localClient.readBatchData(message);
 
-                            remoteClient.postMessage(completeMsg, new MessageDeleteCallback(message.getEntryNum(), syncStatusUpdateCallback));
+                            remoteClient.postMessage(completeMsg);
+
+                            localClient.deleteMessage(completeMsg.getEntryNum());
 
 
                         } else {
 
                             // This is a regular message: post it
-                            remoteClient.postMessage(message, new MessageDeleteCallback(message.getEntryNum(), syncStatusUpdateCallback));
+                            remoteClient.postMessage(message);
+
+                            localClient.deleteMessage(message.getEntryNum());
 
                         }
 

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

@@ -7,6 +7,8 @@ import com.google.common.util.concurrent.MoreExecutors;
 import com.google.protobuf.Int64Value;
 import com.google.protobuf.Timestamp;
 import meerkat.bulletinboard.workers.singleserver.*;
+import meerkat.comm.CommunicationException;
+import meerkat.protobuf.BulletinBoardAPI;
 import meerkat.protobuf.BulletinBoardAPI.*;
 import meerkat.protobuf.Crypto;
 import meerkat.protobuf.Voting.BulletinBoardClientParams;
@@ -166,91 +168,74 @@ public class SingleServerBulletinBoardClient extends SimpleBulletinBoardClient i
         }
     }
 
-    /**
+    private class ReadBatchCallback implements FutureCallback<List<BatchChunk>> {
-     * This callback ties together the different parts of a CompleteBatch as they arrive from the server
-     * It assembles a CompleteBatch from the parts and sends it to the user if all parts arrived
-     * If any part fails to arrive: it invokes the onFailure method
-     */
-    class CompleteBatchReadCallback {
 
+        private final BulletinBoardMessage stub;
         private final FutureCallback<BulletinBoardMessage> callback;
 
-        private List<BatchChunk> batchChunkList;
+        public ReadBatchCallback(BulletinBoardMessage stub, FutureCallback<BulletinBoardMessage> callback) {
-        private BulletinBoardMessage stub;
+            this.stub = stub;
-
-        private AtomicInteger remainingQueries;
-        private AtomicBoolean failed;
-
-        public CompleteBatchReadCallback(FutureCallback<BulletinBoardMessage> callback) {
-
             this.callback = callback;
-
-            remainingQueries = new AtomicInteger(2);
-            failed = new AtomicBoolean(false);
-
         }
 
-        protected void combineAndReturn() {
-
-            if (remainingQueries.decrementAndGet() == 0){
-
-                if (callback != null)
-                    callback.onSuccess(BulletinBoardUtils.gatherBatch(stub, batchChunkList));
-            }
-
-        }
-
-        protected void fail(Throwable t) {
-            if (failed.compareAndSet(false, true)) {
-                if (callback != null)
-                    callback.onFailure(t);
-            }
-        }
-
-        /**
-         * @return a FutureCallback for the Batch Data List that ties to this object
-         */
-        public FutureCallback<List<BatchChunk>> asBatchDataListFutureCallback() {
-            return new FutureCallback<List<BatchChunk>>() {
-
         @Override
         public void onSuccess(List<BatchChunk> result) {
-                    batchChunkList = result;
+            callback.onSuccess(BulletinBoardUtils.gatherBatch(stub, result));
-
-                    combineAndReturn();
         }
 
         @Override
         public void onFailure(Throwable t) {
-                    fail(t);
+            callback.onFailure(t);
         }
 
-            };
     }
 
     /**
-         * @return a FutureCallback for the Bulletin Board Message that ties to this object
+     * This callback receives a message which may be a stub
+     * If the message is not a stub: it returns it as is to a callback function
+     * If it is a stub: it schedules a read of the batch data which will return a complete message to the callback function
      */
-        public FutureCallback<List<BulletinBoardMessage>> asBulletinBoardMessageListFutureCallback() {
+    class CompleteMessageReadCallback implements FutureCallback<List<BulletinBoardMessage>>{
-            return new FutureCallback<List<BulletinBoardMessage>>() {
+
+        private final FutureCallback<BulletinBoardMessage> callback;
+
+        public CompleteMessageReadCallback(FutureCallback<BulletinBoardMessage> callback) {
+
+            this.callback = callback;
+
+        }
 
         @Override
         public void onSuccess(List<BulletinBoardMessage> result) {
-                    if (result.size() < 1){
+            if (result.size() <= 0) {
-                        onFailure(new IllegalArgumentException("Server returned empty message list"));
+                onFailure(new CommunicationException("Could not find required message on the server."));
-                        return;
+            } else {
+
+                BulletinBoardMessage msg = result.get(0);
+
+                if (msg.getMsg().getDataTypeCase() != UnsignedBulletinBoardMessage.DataTypeCase.MSGID) {
+                    callback.onSuccess(msg);
+                } else {
+
+                    // Create job with MAX retries for retrieval of the Batch Data List
+
+                    BatchQuery batchQuery = BatchQuery.newBuilder()
+                            .setMsgID(MessageID.newBuilder()
+                                    .setID(msg.getMsg().getMsgId())
+                                    .build())
+                            .build();
+
+                    SingleServerReadBatchWorker batchWorker = new SingleServerReadBatchWorker(meerkatDBs.get(0), batchQuery, MAX_RETRIES);
+
+                    scheduleWorker(batchWorker, new ReadBatchCallback(msg, callback));
+
+                }
             }
-
-                    stub = result.get(0);
-
-                    combineAndReturn();
         }
 
         @Override
         public void onFailure(Throwable t) {
-                    fail(t);
+            callback.onFailure(t);
-                }
-            };
         }
 
     }
@@ -574,9 +559,9 @@ public class SingleServerBulletinBoardClient extends SimpleBulletinBoardClient i
     }
 
     @Override
-    public void readBatch(MessageID msgID, FutureCallback<BulletinBoardMessage> callback) {
+    public void readMessage(MessageID msgID, FutureCallback<BulletinBoardMessage> callback) {
 
-        // Create job with MAX retries for retrieval of the Bulletin Board Message that defines the batch
+        // Create job with MAX retries for retrieval of the Bulletin Board Message (which may be a stub)
 
         MessageFilterList filterList = MessageFilterList.newBuilder()
                 .addFilter(MessageFilter.newBuilder()
@@ -592,39 +577,11 @@ public class SingleServerBulletinBoardClient extends SimpleBulletinBoardClient i
 
         SingleServerReadMessagesWorker messageWorker = new SingleServerReadMessagesWorker(meerkatDBs.get(0), filterList, MAX_RETRIES);
 
-        // Create job with MAX retries for retrieval of the Batch Data List
-        SingleServerReadBatchWorker batchWorker = new SingleServerReadBatchWorker(meerkatDBs.get(0), batchQuery, MAX_RETRIES);
-
-        // Create callback that will combine the two worker products
-        CompleteBatchReadCallback completeBatchReadCallback = new CompleteBatchReadCallback(callback);
-
         // Submit jobs with wrapped callbacks
-        scheduleWorker(messageWorker, new RetryCallback<>(messageWorker, completeBatchReadCallback.asBulletinBoardMessageListFutureCallback()));
+        scheduleWorker(messageWorker, new RetryCallback<>(messageWorker, new CompleteMessageReadCallback(callback)));
-        scheduleWorker(batchWorker, new RetryCallback<>(batchWorker, completeBatchReadCallback.asBatchDataListFutureCallback()));
 
     }
 
-    private class ReadBatchCallback implements FutureCallback<List<BatchChunk>> {
-
-        private final BulletinBoardMessage stub;
-        private final FutureCallback<BulletinBoardMessage> callback;
-
-        public ReadBatchCallback(BulletinBoardMessage stub, FutureCallback<BulletinBoardMessage> callback) {
-            this.stub = stub;
-            this.callback = callback;
-        }
-
-        @Override
-        public void onSuccess(List<BatchChunk> result) {
-            callback.onSuccess(BulletinBoardUtils.gatherBatch(stub, result));
-        }
-
-        @Override
-        public void onFailure(Throwable t) {
-
-        }
-    }
-
     @Override
     public void readBatchData(BulletinBoardMessage stub, FutureCallback<BulletinBoardMessage> callback) throws IllegalArgumentException{
 

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

@@ -4,7 +4,6 @@ import com.google.common.util.concurrent.FutureCallback;
 
 import com.google.protobuf.Timestamp;
 import meerkat.bulletinboard.workers.multiserver.*;
-import meerkat.protobuf.BulletinBoardAPI;
 import meerkat.protobuf.BulletinBoardAPI.*;
 import meerkat.protobuf.Crypto.Signature;
 import meerkat.protobuf.Voting.*;
@@ -208,11 +207,11 @@ public class ThreadedBulletinBoardClient extends SimpleBulletinBoardClient imple
     }
 
     @Override
-    public void readBatch(MessageID msgID, FutureCallback<BulletinBoardMessage> callback) {
+    public void readMessage(MessageID msgID, FutureCallback<BulletinBoardMessage> callback) {
 
         //Create job
-        MultiServerReadBatchWorker worker =
+        MultiServerReadMessageWorker worker =
-                new MultiServerReadBatchWorker(clients, minAbsoluteRedundancy, msgID, READ_MESSAGES_RETRY_NUM, callback);
+                new MultiServerReadMessageWorker(clients, minAbsoluteRedundancy, msgID, READ_MESSAGES_RETRY_NUM, callback);
 
         // Submit job
         executorService.submit(worker);

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

@@ -22,7 +22,7 @@ public class MultiServerReadBatchDataWorker extends MultiServerGenericReadWorker
 
     @Override
     protected void doRead(MessageID payload, SingleServerBulletinBoardClient client) {
-        client.readBatch(payload, this);
+        client.readMessage(payload, this);
     }
 
 

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

@@ -11,9 +11,9 @@ import java.util.List;
 /**
  * Created by Arbel Deutsch Peled on 27-Dec-15.
  */
-public class MultiServerReadBatchWorker extends MultiServerGenericReadWorker<MessageID, BulletinBoardMessage> {
+public class MultiServerReadMessageWorker extends MultiServerGenericReadWorker<MessageID, BulletinBoardMessage> {
 
-    public MultiServerReadBatchWorker(List<SingleServerBulletinBoardClient> clients,
+    public MultiServerReadMessageWorker(List<SingleServerBulletinBoardClient> clients,
                                         int minServers, MessageID payload, int maxRetry,
                                         FutureCallback<BulletinBoardMessage> futureCallback) {
 
@@ -23,7 +23,7 @@ public class MultiServerReadBatchWorker extends MultiServerGenericReadWorker<Mes
 
     @Override
     protected void doRead(MessageID payload, SingleServerBulletinBoardClient client) {
-        client.readBatch(payload, this);
+        client.readMessage(payload, this);
     }
 
 

bulletin-board-client/src/test/java/meerkat/bulletinboard/BulletinBoardSynchronizerTest.java

@@ -1,7 +1,8 @@
 package meerkat.bulletinboard;
 
 import com.google.common.util.concurrent.FutureCallback;
-import com.google.protobuf.ByteString;
+import com.google.protobuf.*;
+import com.google.protobuf.Timestamp;
 
 import static meerkat.bulletinboard.BulletinBoardSynchronizer.SyncStatus;
 
@@ -57,7 +58,7 @@ public class BulletinBoardSynchronizerTest {
     private static String KEYFILE_PASSWORD1 = "secret";
     private static String CERT1_PEM_EXAMPLE = "/certs/enduser-certs/user1.crt";
 
-    private static GenericBatchDigitalSignature[] signers;
+    private static BulletinBoardSignature[] signers;
     private static ByteString[] signerIDs;
 
     private Semaphore semaphore;
@@ -69,10 +70,10 @@ public class BulletinBoardSynchronizerTest {
         messageGenerator = new BulletinBoardMessageGenerator(new Random(0));
         messageComparator = new BulletinBoardMessageComparator();
 
-        signers = new GenericBatchDigitalSignature[1];
+        signers = new BulletinBoardSignature[1];
         signerIDs = new ByteString[1];
 
-        signers[0] = new GenericBatchDigitalSignature(new ECDSASignature());
+        signers[0] = new GenericBulletinBoardSignature(new ECDSASignature());
         signerIDs[0] = signers[0].getSignerID();
 
         InputStream keyStream = BulletinBoardSynchronizerTest.class.getResourceAsStream(KEYFILE_EXAMPLE);
@@ -203,15 +204,34 @@ public class BulletinBoardSynchronizerTest {
     @Test
     public void testSync() throws SignatureException, CommunicationException, InterruptedException {
 
-        final int BATCH_ID = 1;
+        Timestamp timestamp = Timestamp.newBuilder()
+                .setSeconds(15252162)
+                .setNanos(85914)
+                .build();
 
-        BulletinBoardMessage msg = messageGenerator.generateRandomMessage(signers, 10, 10);
+        BulletinBoardMessage msg = messageGenerator.generateRandomMessage(signers, timestamp, 10, 10);
 
         MessageID msgID = localClient.postMessage(msg);
 
-        CompleteBatch completeBatch = messageGenerator.generateRandomBatch(signers[0],BATCH_ID,10,10,10);
+        timestamp = Timestamp.newBuilder()
+                .setSeconds(51511653)
+                .setNanos(3625)
+                .build();
 
-        localClient.postBatch(completeBatch);
+        BulletinBoardMessage batchMessage = messageGenerator.generateRandomMessage(signers,timestamp,  100, 10);
+
+        MessageID batchMsgID = localClient.postAsBatch(batchMessage, 10);
+
+        BulletinBoardMessage test = localClient.readMessage(batchMsgID);
+
+        BulletinBoardMessage stub = localClient.readMessages(MessageFilterList.newBuilder()
+                .addFilter(MessageFilter.newBuilder()
+                        .setType(FilterType.MSG_ID)
+                        .setId(batchMsgID.getID())
+                        .build())
+                .build()).get(0);
+
+        BulletinBoardMessage test2 = localClient.readBatchData(stub);
 
         synchronizer.subscribeToSyncStatus(new SyncStatusCallback(SyncStatus.SYNCHRONIZED));
 
@@ -244,19 +264,21 @@ public class BulletinBoardSynchronizerTest {
         assertThat("Wrong number of messages returned.", msgList.size() == 1);
         assertThat("Returned message is not equal to original one", messageComparator.compare(msgList.get(0),msg) == 0);
 
-        CompleteBatch returnedBatch = remoteClient.readBatch(BatchSpecificationMessage.newBuilder()
+        BulletinBoardMessage returnedBatchMsg = remoteClient.readMessage(batchMsgID);
-                .setSignerId(signerIDs[0])
-                .setBatchId(BATCH_ID)
-                .build());
 
-        assertThat("Returned batch does not equal original one.", completeBatch.equals(returnedBatch));
+        assertThat("Returned batch does not equal original one.", messageComparator.compare(returnedBatchMsg, batchMessage) == 0);
 
     }
 
     @Test
     public void testServerError() throws SignatureException, CommunicationException, InterruptedException {
 
-        BulletinBoardMessage msg = messageGenerator.generateRandomMessage(signers, 10, 10);
+        Timestamp timestamp = Timestamp.newBuilder()
+                .setSeconds(945736256)
+                .setNanos(276788)
+                .build();
+
+        BulletinBoardMessage msg = messageGenerator.generateRandomMessage(signers, timestamp, 10, 10);
 
         remoteClient.close();
 
@@ -275,17 +297,18 @@ public class BulletinBoardSynchronizerTest {
         synchronizer.stop();
         thread.join();
 
-        if (thrown.size() > 0) {
-            for (Throwable t : thrown)
-                System.err.println(t.getMessage());
-            assertThat("Exception thrown by Synchronizer: " + thrown.get(0).getMessage(), false);
-        }
-
     }
 
     @After
     public void close() {
 
+        if (thrown.size() > 0) {
+            for (Throwable t : thrown) {
+                System.err.println(t.getMessage());
+            }
+            assertThat("Exception thrown by Synchronizer: " + thrown.get(0).getMessage(), false);
+        }
+
         synchronizer.stop();
         localClient.close();
         remoteClient.close();

bulletin-board-client/src/test/java/meerkat/bulletinboard/GenericBulletinBoardClientTester.java

@@ -5,9 +5,13 @@ import com.google.protobuf.ByteString;
 import com.google.protobuf.Timestamp;
 import meerkat.comm.CommunicationException;
 import meerkat.crypto.concrete.ECDSASignature;
+import meerkat.crypto.concrete.SHA256Digest;
 import meerkat.protobuf.BulletinBoardAPI.*;
 import meerkat.protobuf.Crypto;
 import meerkat.util.BulletinBoardMessageComparator;
+import meerkat.util.BulletinBoardMessageGenerator;
+import meerkat.util.BulletinBoardUtils;
+import meerkat.bulletinboard.AsyncBulletinBoardClient.BatchIdentifier;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -27,7 +31,7 @@ public class GenericBulletinBoardClientTester {
 
     // Signature resources
 
-    private GenericBatchDigitalSignature signers[];
+    private BulletinBoardSignature signers[];
     private ByteString[] signerIDs;
 
     private static String KEYFILE_EXAMPLE = "/certs/enduser-certs/user1-key-with-password-secret.p12";
@@ -48,13 +52,15 @@ public class GenericBulletinBoardClientTester {
 
     private RedundancyCallback redundancyCallback;
     private ReadCallback readCallback;
-    private ReadBatchCallback readBatchCallback;
 
     // Sync and misc
 
     private Semaphore jobSemaphore;
     private Vector<Throwable> thrown;
     private Random random;
+    private BulletinBoardMessageGenerator generator;
+
+    private BulletinBoardDigest digest;
 
     // Constructor
 
@@ -62,10 +68,10 @@ public class GenericBulletinBoardClientTester {
 
         this.bulletinBoardClient = bulletinBoardClient;
 
-        signers = new GenericBatchDigitalSignature[2];
+        signers = new GenericBulletinBoardSignature[2];
         signerIDs = new ByteString[signers.length];
-        signers[0] = new GenericBatchDigitalSignature(new ECDSASignature());
+        signers[0] = new GenericBulletinBoardSignature(new ECDSASignature());
-        signers[1] = new GenericBatchDigitalSignature(new ECDSASignature());
+        signers[1] = new GenericBulletinBoardSignature(new ECDSASignature());
 
         InputStream keyStream = getClass().getResourceAsStream(KEYFILE_EXAMPLE);
         char[] password = KEYFILE_PASSWORD1.toCharArray();
@@ -107,6 +113,10 @@ public class GenericBulletinBoardClientTester {
             fail("Couldn't find signing key " + e.getMessage());
         }
 
+        this.random = new Random(0);
+        this.generator = new BulletinBoardMessageGenerator(random);
+        this.digest = new GenericBulletinBoardDigest(new SHA256Digest());
+
     }
 
     // Callback definitions
@@ -137,16 +147,21 @@ public class GenericBulletinBoardClientTester {
 
         @Override
         public void onSuccess(Boolean msg) {
+
             System.err.println("Post operation completed");
-            jobSemaphore.release();
+
-            //TODO: Change Assert mechanism to exception one
             if (isAssert) {
-                if (assertValue) {
+                if (assertValue && !msg) {
-                    assertThat("Post operation failed", msg, is(Boolean.TRUE));
+                    genericHandleFailure(new AssertionError("Post operation failed"));
+                } else if (!assertValue && msg){
+                    genericHandleFailure(new AssertionError("Post operation succeeded unexpectedly"));
                 } else {
-                    assertThat("Post operation succeeded unexpectedly", msg, is(Boolean.FALSE));
+                    jobSemaphore.release();
                 }
+            } else {
+                jobSemaphore.release();
             }
+
         }
 
         @Override
@@ -209,21 +224,24 @@ public class GenericBulletinBoardClientTester {
         }
     }
 
-    private class ReadBatchCallback implements FutureCallback<CompleteBatch> {
+    private class ReadBatchCallback implements FutureCallback<BulletinBoardMessage>{
 
-        private CompleteBatch expectedBatch;
+        private BulletinBoardMessage expectedMsg;
 
-        public ReadBatchCallback(CompleteBatch expectedBatch) {
+        public ReadBatchCallback(BulletinBoardMessage expectedMsg) {
-            this.expectedBatch = expectedBatch;
+            this.expectedMsg = expectedMsg;
         }
 
         @Override
-        public void onSuccess(CompleteBatch batch) {
+        public void onSuccess(BulletinBoardMessage msg) {
 
-            System.err.println(batch);
+            BulletinBoardMessageComparator msgComparator = new BulletinBoardMessageComparator();
+
+            if (msgComparator.compare(msg, expectedMsg) != 0) {
+                genericHandleFailure(new AssertionError("Batch read returned different message.\nExpected:" + expectedMsg + "\nRecieved:" + msg + "\n"));
+            } else {
                 jobSemaphore.release();
-
+            }
-            assertThat("Batch returned is incorrect", batch, is(equalTo(expectedBatch)));
 
         }
 
@@ -233,59 +251,6 @@ public class GenericBulletinBoardClientTester {
         }
     }
 
-    // Randomness generators
-
-    private byte randomByte(){
-        return (byte) random.nextInt();
-    }
-
-    private byte[] randomByteArray(int length) {
-
-        byte[] randomBytes = new byte[length];
-
-        for (int i = 0; i < length ; i++){
-            randomBytes[i] = randomByte();
-        }
-
-        return randomBytes;
-
-    }
-
-    private CompleteBatch createRandomBatch(int signer, int batchId, int length) throws SignatureException {
-
-        CompleteBatch completeBatch = new CompleteBatch();
-
-        // Create data
-
-        completeBatch.setBeginBatchMessage(BeginBatchMessage.newBuilder()
-                .setSignerId(signerIDs[signer])
-                .setBatchId(batchId)
-                .addTag("Test")
-                .build());
-
-        for (int i = 0 ; i < length ; i++){
-
-            BatchChunk batchChunk = BatchChunk.newBuilder()
-                    .setData(ByteString.copyFrom(randomByteArray(i)))
-                    .build();
-
-            completeBatch.appendBatchData(batchChunk);
-
-        }
-
-        completeBatch.setTimestamp(Timestamp.newBuilder()
-                .setSeconds(Math.abs(90))
-                .setNanos(50)
-                .build());
-
-        signers[signer].updateContent(completeBatch);
-
-        completeBatch.setSignature(signers[signer].sign());
-
-        return completeBatch;
-
-    }
-
     // Test methods
 
     /**
@@ -310,7 +275,13 @@ public class GenericBulletinBoardClientTester {
     public void close() {
 
         if (thrown.size() > 0) {
+
+            for (Throwable t : thrown){
+                System.err.println(t.getMessage());
+            }
+
             assert false;
+
         }
 
     }
@@ -394,59 +365,54 @@ public class GenericBulletinBoardClientTester {
 
     /**
      * Tests posting a batch by parts
-     * Also tests not being able to post to a closed batch
      * @throws CommunicationException, SignatureException, InterruptedException
      */
     public void testBatchPost() throws CommunicationException, SignatureException, InterruptedException {
 
-        final int SIGNER = 1;
-        final int BATCH_ID = 100;
         final int BATCH_LENGTH = 100;
+        final int CHUNK_SIZE = 10;
+        final int TAG_NUM = 10;
 
-        CompleteBatch completeBatch = createRandomBatch(SIGNER, BATCH_ID, BATCH_LENGTH);
+        final BulletinBoardMessage msg = generator.generateRandomMessage(signers, BATCH_LENGTH, TAG_NUM);
 
         // Begin batch
 
-        bulletinBoardClient.beginBatch(completeBatch.getBeginBatchMessage(), postCallback);
+        bulletinBoardClient.beginBatch(msg.getMsg().getTagList(), new FutureCallback<BatchIdentifier>() {
+
+            @Override
+            public void onSuccess(final BatchIdentifier identifier) {
+
+                bulletinBoardClient.postBatchData(identifier, BulletinBoardUtils.breakToBatch(msg, CHUNK_SIZE), new FutureCallback<Boolean>() {
+
+                    @Override
+                    public void onSuccess(Boolean result) {
+
+                        bulletinBoardClient.closeBatch(identifier, msg.getMsg().getTimestamp(), msg.getSigList(), postCallback);
+
+                    }
+
+                    @Override
+                    public void onFailure(Throwable t) {
+                        genericHandleFailure(t);
+                    }
+
+                });
+
+            }
+
+            @Override
+            public void onFailure(Throwable t) {
+                genericHandleFailure(t);
+            }
+
+        });
 
         jobSemaphore.acquire();
 
-        // Post data
+        digest.reset();
+        digest.update(msg);
 
-        bulletinBoardClient.postBatchData(signerIDs[SIGNER], BATCH_ID, completeBatch.getBatchDataList(), postCallback);
+        bulletinBoardClient.readMessage(digest.digestAsMessageID(), new ReadBatchCallback(msg));
-
-        jobSemaphore.acquire();
-
-        // Close batch
-
-        CloseBatchMessage closeBatchMessage = completeBatch.getCloseBatchMessage();
-
-        bulletinBoardClient.closeBatch(closeBatchMessage, postCallback);
-
-        jobSemaphore.acquire();
-
-        // Attempt to open batch again
-
-        bulletinBoardClient.beginBatch(completeBatch.getBeginBatchMessage(), failPostCallback);
-
-        // Attempt to add batch data
-
-        bulletinBoardClient.postBatchData(signerIDs[SIGNER], BATCH_ID, completeBatch.getBatchDataList(), failPostCallback);
-
-        jobSemaphore.acquire(2);
-
-        // Read batch data
-
-        BatchSpecificationMessage batchSpecificationMessage =
-                BatchSpecificationMessage.newBuilder()
-                        .setSignerId(signerIDs[SIGNER])
-                        .setBatchId(BATCH_ID)
-                        .setStartPosition(0)
-                        .build();
-
-        readBatchCallback = new ReadBatchCallback(completeBatch);
-
-        bulletinBoardClient.readBatch(batchSpecificationMessage, readBatchCallback);
 
         jobSemaphore.acquire();
 
@@ -454,62 +420,56 @@ public class GenericBulletinBoardClientTester {
 
     /**
      * Posts a complete batch message
-     * Checks reading of the message
+     * Checks reading of the message in two parts
      * @throws CommunicationException, SignatureException, InterruptedException
      */
     public void testCompleteBatchPost() throws CommunicationException, SignatureException, InterruptedException {
 
-        final int SIGNER = 0;
+        final int BATCH_LENGTH = 100;
-        final int BATCH_ID = 101;
+        final int CHUNK_SIZE = 99;
-        final int BATCH_LENGTH = 50;
+        final int TAG_NUM = 8;
+
+        final BulletinBoardMessage msg = generator.generateRandomMessage(signers, BATCH_LENGTH, TAG_NUM);
 
         // Post batch
 
-        CompleteBatch completeBatch = createRandomBatch(SIGNER, BATCH_ID, BATCH_LENGTH);
+        MessageID msgID = bulletinBoardClient.postAsBatch(msg, CHUNK_SIZE, postCallback);
-
-        bulletinBoardClient.postBatch(completeBatch,postCallback);
 
         jobSemaphore.acquire();
 
         // Read batch
 
-        BatchSpecificationMessage batchSpecificationMessage =
+        MessageFilterList filterList = MessageFilterList.newBuilder()
-                BatchSpecificationMessage.newBuilder()
+                .addFilter(MessageFilter.newBuilder()
-                        .setSignerId(signerIDs[SIGNER])
+                        .setType(FilterType.MSG_ID)
-                        .setBatchId(BATCH_ID)
+                        .setId(msgID.getID())
-                        .setStartPosition(0)
-                        .build();
-
-        readBatchCallback = new ReadBatchCallback(completeBatch);
-
-        bulletinBoardClient.readBatch(batchSpecificationMessage, readBatchCallback);
-
-        jobSemaphore.acquire();
-
-    }
-
-    /**
-     * Tests that an unopened batch cannot be closed
-     * @throws CommunicationException, InterruptedException
-     */
-    public void testInvalidBatchClose() throws CommunicationException, InterruptedException {
-
-        final int NON_EXISTENT_BATCH_ID = 999;
-
-        CloseBatchMessage closeBatchMessage =
-                CloseBatchMessage.newBuilder()
-                        .setBatchId(NON_EXISTENT_BATCH_ID)
-                        .setBatchLength(1)
-                        .setSig(Crypto.Signature.getDefaultInstance())
-                        .setTimestamp(Timestamp.newBuilder()
-                                .setSeconds(9)
-                                .setNanos(12)
                         .build())
                 .build();
 
-        // Try to stop the (unopened) batch;
+        bulletinBoardClient.readMessages(filterList, new FutureCallback<List<BulletinBoardMessage>>() {
 
-        bulletinBoardClient.closeBatch(closeBatchMessage, failPostCallback);
+            @Override
+            public void onSuccess(List<BulletinBoardMessage> msgList) {
+
+                if (msgList.size() != 1) {
+
+                    genericHandleFailure(new AssertionError("Wrong number of stubs returned. Expected: 1; Found: " + msgList.size()));
+
+                } else {
+
+                    BulletinBoardMessage retrievedMsg = msgList.get(0);
+                    bulletinBoardClient.readBatchData(retrievedMsg, new ReadBatchCallback(msg));
+
+                }
+
+            }
+
+            @Override
+            public void onFailure(Throwable t) {
+                genericHandleFailure(t);
+            }
+
+        });
 
         jobSemaphore.acquire();
 

bulletin-board-client/src/test/java/meerkat/bulletinboard/GenericSubscriptionClientTester.java

@@ -23,7 +23,7 @@ import static org.junit.Assert.fail;
  */
 public class GenericSubscriptionClientTester {
 
-    private GenericBatchDigitalSignature signers[];
+    private BulletinBoardSignature signers[];
     private ByteString[] signerIDs;
 
     private static String KEYFILE_EXAMPLE = "/certs/enduser-certs/user1-key-with-password-secret.p12";
@@ -47,10 +47,10 @@ public class GenericSubscriptionClientTester {
 
         this.bulletinBoardClient = bulletinBoardClient;
 
-        signers = new GenericBatchDigitalSignature[2];
+        signers = new BulletinBoardSignature[2];
         signerIDs = new ByteString[signers.length];
-        signers[0] = new GenericBatchDigitalSignature(new ECDSASignature());
+        signers[0] = new GenericBulletinBoardSignature(new ECDSASignature());
-        signers[1] = new GenericBatchDigitalSignature(new ECDSASignature());
+        signers[1] = new GenericBulletinBoardSignature(new ECDSASignature());
 
         InputStream keyStream = getClass().getResourceAsStream(KEYFILE_EXAMPLE);
         char[] password = KEYFILE_PASSWORD1.toCharArray();

bulletin-board-client/src/test/java/meerkat/bulletinboard/LocalBulletinBoardClientTest.java

@@ -100,13 +100,6 @@ public class LocalBulletinBoardClientTest {
 
     }
 
-    @Test
-    public void testInvalidBatchClose() throws CommunicationException, InterruptedException {
-
-        clientTest.testInvalidBatchClose();
-
-    }
-
     @Test
     public void testSubscription() throws SignatureException, CommunicationException {
         subscriptionTester.init();

bulletin-board-client/src/test/java/meerkat/bulletinboard/ThreadedBulletinBoardClientIntegrationTest.java

@@ -85,11 +85,4 @@ public class ThreadedBulletinBoardClientIntegrationTest {
 
     }
 
-    @Test
-    public void testInvalidBatchClose() throws CommunicationException, InterruptedException {
-
-        clientTest.testInvalidBatchClose();
-
-    }
-
 }

bulletin-board-server/src/main/java/meerkat/bulletinboard/sqlserver/BulletinBoardSQLServer.java

@@ -19,6 +19,7 @@ import meerkat.crypto.DigitalSignature;
 import meerkat.crypto.concrete.SHA256Digest;
 
 import meerkat.protobuf.BulletinBoardAPI.*;
+import meerkat.protobuf.Comm;
 import meerkat.protobuf.Crypto.Signature;
 import meerkat.protobuf.Crypto.SignatureVerificationKey;
 
@@ -546,9 +547,17 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 
 	}
 
+	private void checkConnection() throws CommunicationException {
+		if (jdbcTemplate == null) {
+			throw new CommunicationException("DB connection not initialized");
+		}
+	}
+
 	@Override
 	public BoolValue postMessage(BulletinBoardMessage msg) throws CommunicationException {
 
+		checkConnection();
+
 		// Perform a post, calculate the message ID and check the signature for authenticity
 		if (postMessage(msg, null) != -1){
 			return BoolValue.newBuilder().setValue(true).build();	// Message was posted
@@ -561,6 +570,8 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public BoolValue deleteMessage(MessageID msgID) throws CommunicationException {
 
+		checkConnection();
+
 		String sql = sqlQueryProvider.getSQLString(QueryType.DELETE_MSG_BY_ID);
 		Map namedParameters = new HashMap();
 
@@ -577,6 +588,8 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public BoolValue deleteMessage(long entryNum) throws CommunicationException {
 
+		checkConnection();
+
 		String sql = sqlQueryProvider.getSQLString(QueryType.DELETE_MSG_BY_ENTRY);
 		Map namedParameters = new HashMap();
 
@@ -702,6 +715,8 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public void readMessages(MessageFilterList filterList, MessageOutputStream<BulletinBoardMessage> out) throws CommunicationException {
 
+		checkConnection();
+
 		BulletinBoardMessageList.Builder resultListBuilder = BulletinBoardMessageList.newBuilder();
 
 		// SQL length is roughly 50 characters per filter + 50 for the query itself
@@ -725,6 +740,8 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public Int32Value getMessageCount(MessageFilterList filterList) throws CommunicationException {
 
+		checkConnection();
+
 		BulletinBoardMessageList.Builder resultListBuilder = BulletinBoardMessageList.newBuilder();
 
 		// SQL length is roughly 50 characters per filter + 50 for the query itself
@@ -793,6 +810,8 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public Int64Value beginBatch(BeginBatchMessage message) throws CommunicationException {
 
+		checkConnection();
+
 		// Store tags
 		String sql = sqlQueryProvider.getSQLString(QueryType.STORE_BATCH_TAGS);
 		MapSqlParameterSource namedParameters = new MapSqlParameterSource();
@@ -814,6 +833,8 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public BoolValue postBatchMessage(BatchMessage batchMessage) throws CommunicationException{
 
+		checkConnection();
+
 		// Make sure batch is open
 		if (!isBatchOpen(batchMessage.getBatchId())) {
 			return BoolValue.newBuilder().setValue(false).build();
@@ -837,6 +858,7 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public BoolValue closeBatch(CloseBatchMessage message) throws CommunicationException {
 
+		checkConnection();
 
 		// Check batch size
 
@@ -916,6 +938,8 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public void readBatch(BatchQuery batchQuery, MessageOutputStream<BatchChunk> out) throws CommunicationException, IllegalArgumentException{
 
+		checkConnection();
+
 		// Check that batch is closed
 		if (!isBatchClosed(batchQuery.getMsgID())) {
 			throw new IllegalArgumentException("No such batch");
@@ -950,7 +974,9 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	}
 
 	@Override
-	public SyncQuery generateSyncQuery(GenerateSyncQueryParams generateSyncQueryParams) {
+	public SyncQuery generateSyncQuery(GenerateSyncQueryParams generateSyncQueryParams) throws CommunicationException{
+
+		checkConnection();
 
 		if (generateSyncQueryParams == null
 				|| !generateSyncQueryParams.hasFilterList()
@@ -1029,6 +1055,8 @@ public class BulletinBoardSQLServer implements DeletableBulletinBoardServer{
 	@Override
 	public SyncQueryResponse querySync(SyncQuery syncQuery) throws CommunicationException {
 
+		checkConnection();
+
 		if (syncQuery == null){
 			return SyncQueryResponse.newBuilder()
 					.setLastEntryNum(-1)

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

@@ -87,19 +87,20 @@ public interface AsyncBulletinBoardClient extends BulletinBoardClient {
      * Read all messages posted matching the given filter in an asynchronous manner
      * Note that if messages haven't been "fully posted", this might return a different
      * set of messages in different calls. However, messages that are fully posted
-     * are guaranteed to be included.
+     * are guaranteed to be included
      * Also: batch messages are returned as stubs.
-     * @param filterList return only messages that match the filters (null means no filtering).
+     * @param filterList return only messages that match the filters (null means no filtering)
      * @param callback is a callback function class for handling results of the operation
      */
     public void readMessages(MessageFilterList filterList, FutureCallback<List<BulletinBoardMessage>> callback);
 
     /**
-     * Read a given batch message from the bulletin board
+     * Read a given message from the bulletin board
-     * @param msgID is the batch message ID to be read
+     * If the message is a batch: returns a complete message containing the batch data as well as the metadata
+     * @param msgID is the ID of the message to be read
      * @param callback is a callback class for handling the result of the operation
      */
-    public void readBatch(MessageID msgID, FutureCallback<BulletinBoardMessage> callback);
+    public void readMessage(MessageID msgID, FutureCallback<BulletinBoardMessage> callback);
 
     /**
      * Read batch data for a specific stub message

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

@@ -55,12 +55,13 @@ public interface BulletinBoardClient {
     MessageID postAsBatch(BulletinBoardMessage msg, int chunkSize) throws CommunicationException;
 
     /**
-     * Read a given batch message from the bulletin board
+     * Read a given message from the bulletin board
-     * @param msgID is the batch message ID to be read
+     * If the message is a batch: returns a complete message containing the batch data as well as the metadata
-     * @return the complete batch
+     * @param msgID is the ID of the message to be read
+     * @return the complete message
      * @throws CommunicationException if operation is unsuccessful
      */
-    BulletinBoardMessage readBatch(MessageID msgID) throws CommunicationException;
+    BulletinBoardMessage readMessage(MessageID msgID) throws CommunicationException;
 
     /**
      * Read batch data for a specific stub message