version2/src/java/iotcloud/Table.java

   1 package iotcloud;
   2
   3 import java.util.Iterator;
   4 import java.util.Random;
   5 import java.util.Arrays;
   6 import java.util.Map;
   7 import java.util.Set;
   8 import java.util.List;
   9 import java.util.Vector;
  10 import java.util.HashMap;
  11 import java.util.HashSet;
  12 import java.util.ArrayList;
  13 import java.util.Collections;
  14 import java.nio.ByteBuffer;
  15
  16 /**
  17  * IoTTable data structure.  Provides client interface.
  18  * @author Brian Demsky
  19  * @version 1.0
  20  */
  21
  22 final public class Table {
  23
  24
  25         /* Constants */
  26         static final int FREE_SLOTS = 10; // Number of slots that should be kept free
  27         static final int SKIP_THRESHOLD = 10;
  28         static final double RESIZE_MULTIPLE = 1.2;
  29         static final double RESIZE_THRESHOLD = 0.75;
  30         static final int REJECTED_THRESHOLD = 5;
  31
  32         /* Helper Objects */
  33         private SlotBuffer buffer = null;
  34         private CloudComm cloud = null;
  35         private Random random = null;
  36         private TableStatus liveTableStatus = null;
  37         private PendingTransaction pendingTransactionBuilder = null; // Pending Transaction used in building a Pending Transaction
  38         private Transaction lastPendingTransactionSpeculatedOn = null; // Last transaction that was speculated on from the pending transaction
  39         private Transaction firstPendingTransaction = null; // first transaction in the pending transaction list
  40
  41         /* Variables */
  42         private int numberOfSlots = 0;  // Number of slots stored in buffer
  43         private int bufferResizeThreshold = 0; // Threshold on the number of live slots before a resize is needed
  44         private long liveSlotCount = 0; // Number of currently live slots
  45         private long oldestLiveSlotSequenceNumver = 0;  // Smallest sequence number of the slot with a live entry
  46         private long localMachineId = 0; // Machine ID of this client device
  47         private long sequenceNumber = 0; // Largest sequence number a client has received
  48         private int smallestTableStatusSeen = -1; // Smallest Table Status that was seen in the latest slots sent from the server
  49         private int largestTableStatusSeen = -1; // Largest Table Status that was seen in the latest slots sent from the server
  50         private long localTransactionSequenceNumber = 0; // Local sequence number counter for transactions
  51         private long lastTransactionSequenceNumberSpeculatedOn = -1; // the last transaction that was speculated on
  52         private long oldestTransactionSequenceNumberSpeculatedOn = -1; // the oldest transaction that was speculated on
  53         private long localArbitrationSequenceNumber = 0;
  54         private boolean hadPartialSendToServer = false;
  55         private boolean attemptedToSendToServer = false;
  56
  57         /* Data Structures  */
  58         private Map<IoTString, KeyValue> committedKeyValueTable = null; // Table of committed key value pairs
  59         private Map<IoTString, KeyValue> speculatedKeyValueTable = null; // Table of speculated key value pairs, if there is a speculative value
  60         private Map<IoTString, KeyValue> pendingTransactionSpeculatedKeyValueTable = null; // Table of speculated key value pairs, if there is a speculative value from the pending transactions
  61         private Map<IoTString, NewKey> liveNewKeyTable = null; // Table of live new keys
  62         private HashMap<Long, Pair<Long, Liveness>> lastMessageTable = null; // Last message sent by a client machine id -> (Seq Num, Slot or LastMessage);
  63         private HashMap<Long, HashSet<RejectedMessage>> rejectedMessageWatchListTable = null; // Table of machine Ids and the set of rejected messages they have not seen yet
  64         private Map<IoTString, Long> arbitratorTable = null; // Table of keys and their arbitrators
  65         private Map<Pair<Long, Long>, Abort> liveAbortTable = null; // Table live abort messages
  66         private Map<Long, Map<Pair<Long, Integer>, TransactionPart>> newTransactionParts = null; // transaction parts that are seen in this latest round of slots from the server
  67         private Map<Long, Map<Pair<Long, Integer>, CommitPart>> newCommitParts = null; // commit parts that are seen in this latest round of slots from the server
  68         private Map<Long, Long> lastArbitratedTransactionNumberByArbitratorTable = null; // Last transaction sequence number that an arbitrator arbitrated on
  69         private Map<Long, Transaction> liveTransactionBySequenceNumberTable = null; // live transaction grouped by the sequence number
  70         private Map<Pair<Long, Long>, Transaction> liveTransactionByTransactionIdTable = null; // live transaction grouped by the transaction ID
  71         private Map<Long, Map<Long, Commit>> liveCommitsTable = null;
  72         private Map<IoTString, Commit> liveCommitsByKeyTable = null;
  73         private Map<Long, Long> lastCommitSeenSequenceNumberByArbitratorTable = null;
  74         private Vector<Long> rejectedSlotList = null; // List of rejected slots that have yet to be sent to the server
  75         private List<Transaction> pendingTransactionQueue = null;
  76         private List<ArbitrationRound> pendingSendArbitrationRounds = null;
  77         private List<Entry> pendingSendArbitrationEntriesToDelete = null;
  78         private Map<Transaction, List<Integer>> transactionPartsSent = null;
  79         private Map<Long, TransactionStatus> outstandingTransactionStatus = null;
  80         private Map<Long, Abort> liveAbortsGeneratedByLocal = null;
  81         private Set<Pair<Long, Long>> offlineTransactionsCommittedAndAtServer = null;
  82         private Map<Long, Pair<String, Integer>> localCommunicationTable = null;
  83         private Map<Long, Long> lastTransactionSeenFromMachineFromServer = null;
  84         private Map<Long, Long> lastArbitrationDataLocalSequenceNumberSeenFromArbitrator = null;
  85
  86
  87
  88
  89
  90         public Table(String baseurl, String password, long _localMachineId, int listeningPort) {
  91                 localMachineId = _localMachineId;
  92                 cloud = new CloudComm(this, baseurl, password, listeningPort);
  93
  94                 init();
  95         }
  96
  97         public Table(CloudComm _cloud, long _localMachineId) {
  98                 localMachineId = _localMachineId;
  99                 cloud = _cloud;
 100
 101                 init();
 102         }
 103
 104         /**
 105          * Init all the stuff needed for for table usage
 106          */
 107         private void init() {
 108
 109                 // Init helper objects
 110                 random = new Random();
 111                 buffer = new SlotBuffer();
 112
 113                 // Set Variables
 114                 oldestLiveSlotSequenceNumver = 1;
 115
 116                 // init data structs
 117                 committedKeyValueTable = new HashMap<IoTString, KeyValue>();
 118                 speculatedKeyValueTable = new HashMap<IoTString, KeyValue>();
 119                 pendingTransactionSpeculatedKeyValueTable = new HashMap<IoTString, KeyValue>();
 120                 liveNewKeyTable = new HashMap<IoTString, NewKey>();
 121                 lastMessageTable = new HashMap<Long, Pair<Long, Liveness>>();
 122                 rejectedMessageWatchListTable = new HashMap<Long, HashSet<RejectedMessage>>();
 123                 arbitratorTable = new HashMap<IoTString, Long>();
 124                 liveAbortTable = new HashMap<Pair<Long, Long>, Abort>();
 125                 newTransactionParts = new HashMap<Long, Map<Pair<Long, Integer>, TransactionPart>>();
 126                 newCommitParts = new HashMap<Long, Map<Pair<Long, Integer>, CommitPart>>();
 127                 lastArbitratedTransactionNumberByArbitratorTable = new HashMap<Long, Long>();
 128                 liveTransactionBySequenceNumberTable = new HashMap<Long, Transaction>();
 129                 liveTransactionByTransactionIdTable = new HashMap<Pair<Long, Long>, Transaction>();
 130                 liveCommitsTable = new HashMap<Long, Map<Long, Commit>>();
 131                 liveCommitsByKeyTable = new HashMap<IoTString, Commit>();
 132                 lastCommitSeenSequenceNumberByArbitratorTable = new HashMap<Long, Long>();
 133                 rejectedSlotList = new Vector<Long>();
 134                 pendingTransactionQueue = new ArrayList<Transaction>();
 135                 pendingSendArbitrationEntriesToDelete = new ArrayList<Entry>();
 136                 transactionPartsSent = new HashMap<Transaction, List<Integer>>();
 137                 outstandingTransactionStatus = new HashMap<Long, TransactionStatus>();
 138                 liveAbortsGeneratedByLocal = new HashMap<Long, Abort>();
 139                 offlineTransactionsCommittedAndAtServer = new HashSet<Pair<Long, Long>>();
 140                 localCommunicationTable = new HashMap<Long, Pair<String, Integer>>();
 141                 lastTransactionSeenFromMachineFromServer = new HashMap<Long, Long>();
 142                 pendingSendArbitrationRounds = new ArrayList<ArbitrationRound>();
 143                 lastArbitrationDataLocalSequenceNumberSeenFromArbitrator = new HashMap<Long, Long>();
 144
 145
 146                 // Other init stuff
 147                 numberOfSlots = buffer.capacity();
 148                 setResizeThreshold();
 149         }
 150
 151         // TODO: delete method
 152         public synchronized void printSlots() {
 153                 long o = buffer.getOldestSeqNum();
 154                 long n = buffer.getNewestSeqNum();
 155
 156                 int[] types = new int[10];
 157
 158                 int num = 0;
 159
 160                 int livec = 0;
 161                 int deadc = 0;
 162                 for (long i = o; i < (n + 1); i++) {
 163                         Slot s = buffer.getSlot(i);
 164
 165                         Vector<Entry> entries = s.getEntries();
 166
 167                         for (Entry e : entries) {
 168                                 if (e.isLive()) {
 169                                         int type = e.getType();
 170                                         types[type] = types[type] + 1;
 171                                         num++;
 172                                         livec++;
 173                                 } else {
 174                                         deadc++;
 175                                 }
 176                         }
 177                 }
 178
 179                 for (int i = 0; i < 10; i++) {
 180                         System.out.println(i + "    " + types[i]);
 181                 }
 182                 System.out.println("Live count:   " + livec);
 183                 System.out.println("Dead count:   " + deadc);
 184                 System.out.println("Old:   " + o);
 185                 System.out.println("New:   " + n);
 186                 System.out.println("Size:   " + buffer.size());
 187
 188                 // List<IoTString> strList = new ArrayList<IoTString>();
 189                 // for (int i = 0; i < 100; i++) {
 190                 //      String keyA = "a" + i;
 191                 //      String keyB = "b" + i;
 192                 //      String keyC = "c" + i;
 193                 //      String keyD = "d" + i;
 194
 195                 //      IoTString iKeyA = new IoTString(keyA);
 196                 //      IoTString iKeyB = new IoTString(keyB);
 197                 //      IoTString iKeyC = new IoTString(keyC);
 198                 //      IoTString iKeyD = new IoTString(keyD);
 199
 200                 //      strList.add(iKeyA);
 201                 //      strList.add(iKeyB);
 202                 //      strList.add(iKeyC);
 203                 //      strList.add(iKeyD);
 204                 // }
 205
 206
 207                 // for (Long l : commitMap.keySet()) {
 208                 //      for (Long l2 : commitMap.get(l).keySet()) {
 209                 //              for (KeyValue kv : commitMap.get(l).get(l2).getkeyValueUpdateSet()) {
 210                 //                      strList.remove(kv.getKey());
 211                 //                      System.out.print(kv.getKey() + "    ");
 212                 //              }
 213                 //      }
 214                 // }
 215
 216                 // System.out.println();
 217                 // System.out.println();
 218
 219                 // for (IoTString s : strList) {
 220                 //      System.out.print(s + "    ");
 221                 // }
 222                 // System.out.println();
 223                 // System.out.println(strList.size());
 224         }
 225
 226         /**
 227          * Initialize the table by inserting a table status as the first entry into the table status
 228          * also initialize the crypto stuff.
 229          */
 230         public synchronized void initTable() throws ServerException {
 231                 cloud.initSecurity();
 232
 233                 // Create the first insertion into the block chain which is the table status
 234                 Slot s = new Slot(this, 1, localMachineId);
 235                 TableStatus status = new TableStatus(s, numberOfSlots);
 236                 s.addEntry(status);
 237                 Slot[] array = cloud.putSlot(s, numberOfSlots);
 238
 239                 if (array == null) {
 240                         array = new Slot[] {s};
 241                         // update local block chain
 242                         validateAndUpdate(array, true);
 243                 } else if (array.length == 1) {
 244                         // in case we did push the slot BUT we failed to init it
 245                         validateAndUpdate(array, true);
 246                 } else {
 247                         throw new Error("Error on initialization");
 248                 }
 249         }
 250
 251         /**
 252          * Rebuild the table from scratch by pulling the latest block chain from the server.
 253          */
 254         public synchronized void rebuild() throws ServerException {
 255                 // Just pull the latest slots from the server
 256                 Slot[] newslots = cloud.getSlots(sequenceNumber + 1);
 257                 validateAndUpdate(newslots, true);
 258         }
 259
 260 // public String toString() {
 261 //      String retString = " Committed Table: \n";
 262 //      retString += "---------------------------\n";
 263 //      retString += commitedTable.toString();
 264
 265 //      retString += "\n\n";
 266
 267 //      retString += " Speculative Table: \n";
 268 //      retString += "---------------------------\n";
 269 //      retString += speculativeTable.toString();
 270
 271 //      return retString;
 272 // }
 273
 274         public synchronized void addLocalCommunication(long arbitrator, String hostName, int portNumber) {
 275                 localCommunicationTable.put(arbitrator, new Pair<String, Integer>(hostName, portNumber));
 276         }
 277
 278         public synchronized Long getArbitrator(IoTString key) {
 279                 return arbitratorTable.get(key);
 280         }
 281
 282         public synchronized void close() {
 283                 cloud.close();
 284         }
 285
 286         public synchronized IoTString getCommitted(IoTString key)  {
 287                 KeyValue kv = committedKeyValueTable.get(key);
 288
 289                 if (kv != null) {
 290                         return kv.getValue();
 291                 } else {
 292                         return null;
 293                 }
 294         }
 295
 296         public synchronized IoTString getSpeculative(IoTString key) {
 297                 KeyValue kv = pendingTransactionSpeculatedKeyValueTable.get(key);
 298
 299                 if (kv == null) {
 300                         kv = speculatedKeyValueTable.get(key);
 301                 }
 302
 303                 if (kv == null) {
 304                         kv = committedKeyValueTable.get(key);
 305                 }
 306
 307                 if (kv != null) {
 308                         return kv.getValue();
 309                 } else {
 310                         return null;
 311                 }
 312         }
 313
 314         public synchronized IoTString getCommittedAtomic(IoTString key) {
 315                 KeyValue kv = committedKeyValueTable.get(key);
 316
 317                 if (arbitratorTable.get(key) == null) {
 318                         throw new Error("Key not Found.");
 319                 }
 320
 321                 // Make sure new key value pair matches the current arbitrator
 322                 if (!pendingTransactionBuilder.checkArbitrator(arbitratorTable.get(key))) {
 323                         // TODO: Maybe not throw en error
 324                         throw new Error("Not all Key Values Match Arbitrator.");
 325                 }
 326
 327                 if (kv != null) {
 328                         pendingTransactionBuilder.addKVGuard(new KeyValue(key, kv.getValue()));
 329                         return kv.getValue();
 330                 } else {
 331                         pendingTransactionBuilder.addKVGuard(new KeyValue(key, null));
 332                         return null;
 333                 }
 334         }
 335
 336         public synchronized IoTString getSpeculativeAtomic(IoTString key) {
 337                 if (arbitratorTable.get(key) == null) {
 338                         throw new Error("Key not Found.");
 339                 }
 340
 341                 // Make sure new key value pair matches the current arbitrator
 342                 if (!pendingTransactionBuilder.checkArbitrator(arbitratorTable.get(key))) {
 343                         // TODO: Maybe not throw en error
 344                         throw new Error("Not all Key Values Match Arbitrator.");
 345                 }
 346
 347                 KeyValue kv = pendingTransactionSpeculatedKeyValueTable.get(key);
 348
 349                 if (kv == null) {
 350                         kv = speculatedKeyValueTable.get(key);
 351                 }
 352
 353                 if (kv == null) {
 354                         kv = committedKeyValueTable.get(key);
 355                 }
 356
 357                 if (kv != null) {
 358                         pendingTransactionBuilder.addKVGuard(new KeyValue(key, kv.getValue()));
 359                         return kv.getValue();
 360                 } else {
 361                         pendingTransactionBuilder.addKVGuard(new KeyValue(key, null));
 362                         return null;
 363                 }
 364         }
 365
 366         public synchronized boolean update()  {
 367                 try {
 368                         Slot[] newSlots = cloud.getSlots(sequenceNumber + 1);
 369                         validateAndUpdate(newSlots, false);
 370                         sendToServer(null);
 371
 372                         return true;
 373                 } catch (Exception e) {
 374                         // e.printStackTrace();
 375                 }
 376
 377                 return false;
 378         }
 379
 380         public synchronized boolean createNewKey(IoTString keyName, long machineId) throws ServerException {
 381                 while (true) {
 382                         if (arbitratorTable.get(keyName) != null) {
 383                                 // There is already an arbitrator
 384                                 return false;
 385                         }
 386
 387                         NewKey newKey = new NewKey(null, keyName, machineId);
 388                         if (sendToServer(newKey)) {
 389                                 // If successfully inserted
 390                                 return true;
 391                         }
 392                 }
 393         }
 394
 395         public synchronized void startTransaction() {
 396                 // Create a new transaction, invalidates any old pending transactions.
 397                 pendingTransactionBuilder = new PendingTransaction(localMachineId);
 398         }
 399
 400         public synchronized void addKV(IoTString key, IoTString value) {
 401
 402                 // Make sure it is a valid key
 403                 if (arbitratorTable.get(key) == null) {
 404                         throw new Error("Key not Found.");
 405                 }
 406
 407                 // Make sure new key value pair matches the current arbitrator
 408                 if (!pendingTransactionBuilder.checkArbitrator(arbitratorTable.get(key))) {
 409                         // TODO: Maybe not throw en error
 410                         throw new Error("Not all Key Values Match Arbitrator.");
 411                 }
 412
 413                 // Add the key value to this transaction
 414                 KeyValue kv = new KeyValue(key, value);
 415                 pendingTransactionBuilder.addKV(kv);
 416         }
 417
 418         public synchronized TransactionStatus commitTransaction() {
 419
 420                 if (pendingTransactionBuilder.getKVUpdates().size() == 0) {
 421                         // transaction with no updates will have no effect on the system
 422                         return new TransactionStatus(TransactionStatus.StatusNoEffect, -1);
 423                 }
 424
 425                 // Set the local transaction sequence number and increment
 426                 pendingTransactionBuilder.setClientLocalSequenceNumber(localTransactionSequenceNumber);
 427                 localTransactionSequenceNumber++;
 428
 429                 // Create the transaction status
 430                 TransactionStatus transactionStatus = new TransactionStatus(TransactionStatus.StatusPending, pendingTransactionBuilder.getArbitrator());
 431
 432                 // Create the new transaction
 433                 Transaction newTransaction = pendingTransactionBuilder.createTransaction();
 434                 newTransaction.setTransactionStatus(transactionStatus);
 435
 436                 if (pendingTransactionBuilder.getArbitrator() != localMachineId) {
 437                         // Add it to the queue and invalidate the builder for safety
 438                         pendingTransactionQueue.add(newTransaction);
 439                 } else {
 440                         arbitrateOnLocalTransaction(newTransaction);
 441                         updateLiveStateFromLocal();
 442                 }
 443
 444                 pendingTransactionBuilder = new PendingTransaction(localMachineId);
 445
 446                 try {
 447                         sendToServer(null);
 448                 } catch (ServerException e) {
 449
 450                         Set<Long> arbitratorTriedAndFailed = new HashSet<Long>();
 451                         for (Iterator<Transaction> iter = pendingTransactionQueue.iterator(); iter.hasNext(); ) {
 452                                 Transaction transaction = iter.next();
 453
 454                                 if (arbitratorTriedAndFailed.contains(transaction.getArbitrator())) {
 455                                         // Already contacted this client so ignore all attempts to contact this client
 456                                         // to preserve ordering for arbitrator
 457                                         continue;
 458                                 }
 459
 460                                 Pair<Boolean, Boolean> sendReturn = sendTransactionToLocal(transaction);
 461
 462                                 if (sendReturn.getFirst()) {
 463                                         // Failed to contact over local
 464                                         arbitratorTriedAndFailed.add(transaction.getArbitrator());
 465                                 } else {
 466                                         // Successful contact or should not contact
 467
 468                                         if (sendReturn.getSecond()) {
 469                                                 // did arbitrate
 470                                                 iter.remove();
 471                                         }
 472                                 }
 473                         }
 474                 }
 475
 476                 updateLiveStateFromLocal();
 477
 478                 return transactionStatus;
 479         }
 480
 481         /**
 482          * Get the machine ID for this client
 483          */
 484         public long getMachineId() {
 485                 return localMachineId;
 486         }
 487
 488         /**
 489          * Decrement the number of live slots that we currently have
 490          */
 491         public void decrementLiveCount() {
 492                 liveSlotCount--;
 493         }
 494
 495         /**
 496          * Recalculate the new resize threshold
 497          */
 498         private void setResizeThreshold() {
 499                 int resizeLower = (int) (RESIZE_THRESHOLD * numberOfSlots);
 500                 bufferResizeThreshold = resizeLower - 1 + random.nextInt(numberOfSlots - resizeLower);
 501         }
 502
 503         private boolean sendToServer(NewKey newKey) throws ServerException {
 504
 505                 try {
 506                         // While we have stuff that needs inserting into the block chain
 507                         while ((pendingTransactionQueue.size() > 0) || (pendingSendArbitrationRounds.size() > 0) || (newKey != null)) {
 508
 509                                 // Create the slot
 510                                 Slot slot = new Slot(this, sequenceNumber + 1, localMachineId, buffer.getSlot(sequenceNumber).getHMAC());
 511
 512                                 // Try to fill the slot with data
 513                                 ThreeTuple<Boolean, Integer, Boolean> fillSlotsReturn = fillSlot(slot, false, newKey);
 514                                 boolean needsResize = fillSlotsReturn.getFirst();
 515                                 int newSize = fillSlotsReturn.getSecond();
 516                                 Boolean insertedNewKey = fillSlotsReturn.getThird();
 517
 518                                 if (needsResize) {
 519                                         // Reset which transaction to send
 520                                         for (Transaction transaction : transactionPartsSent.keySet()) {
 521                                                 transaction.resetNextPartToSend();
 522
 523                                                 // Set the transaction sequence number back to nothing
 524                                                 if (!transaction.didSendAPartToServer()) {
 525                                                         transaction.setSequenceNumber(-1);
 526                                                 }
 527                                         }
 528
 529                                         // Clear the sent data since we are trying again
 530                                         pendingSendArbitrationEntriesToDelete.clear();
 531                                         transactionPartsSent.clear();
 532
 533                                         // We needed a resize so try again
 534                                         fillSlot(slot, true, newKey);
 535                                 }
 536
 537                                 // Try to send to the server
 538                                 ThreeTuple<Boolean, Boolean, Slot[]> sendSlotsReturn = sendSlotsToServer(slot, newSize, newKey != null);
 539
 540                                 if (/*sendSlotsReturn.getSecond() || */sendSlotsReturn.getFirst()) {
 541                                         // Did insert into the block chain
 542
 543                                         if (sendSlotsReturn.getFirst()) {
 544                                                 // This slot was what was inserted not a previous slot
 545
 546                                                 // New Key was successfully inserted into the block chain so dont want to insert it again
 547                                                 newKey = null;
 548                                         }
 549
 550                                         // Remove the aborts and commit parts that were sent from the pending to send queue
 551                                         for (Iterator<ArbitrationRound> iter = pendingSendArbitrationRounds.iterator(); iter.hasNext(); ) {
 552                                                 ArbitrationRound round = iter.next();
 553                                                 round.removeParts(pendingSendArbitrationEntriesToDelete);
 554
 555                                                 if (round.isDoneSending()) {
 556                                                         // Sent all the parts
 557                                                         iter.remove();
 558                                                 }
 559                                         }
 560
 561                                         for (Transaction transaction : transactionPartsSent.keySet()) {
 562
 563
 564                                                 transaction.resetServerFailure();
 565
 566
 567                                                 // Update which transactions parts still need to be sent
 568                                                 transaction.removeSentParts(transactionPartsSent.get(transaction));
 569
 570                                                 // Add the transaction status to the outstanding list
 571                                                 outstandingTransactionStatus.put(transaction.getSequenceNumber(), transaction.getTransactionStatus());
 572
 573                                                 // Update the transaction status
 574                                                 transaction.getTransactionStatus().setStatus(TransactionStatus.StatusSentPartial);
 575
 576                                                 // Check if all the transaction parts were successfully sent and if so then remove it from pending
 577                                                 if (transaction.didSendAllParts()) {
 578                                                         transaction.getTransactionStatus().setStatus(TransactionStatus.StatusSentFully);
 579                                                         pendingTransactionQueue.remove(transaction);
 580                                                 }
 581                                         }
 582                                 } else {
 583                                         // Reset which transaction to send
 584                                         for (Transaction transaction : transactionPartsSent.keySet()) {
 585                                                 transaction.resetNextPartToSend();
 586                                                 transaction.resetNextPartToSend();
 587
 588                                                 // Set the transaction sequence number back to nothing
 589                                                 if (!transaction.didSendAPartToServer()) {
 590                                                         transaction.setSequenceNumber(-1);
 591                                                 }
 592                                         }
 593                                 }
 594
 595                                 // Clear the sent data in preparation for next send
 596                                 pendingSendArbitrationEntriesToDelete.clear();
 597                                 transactionPartsSent.clear();
 598
 599                                 if (sendSlotsReturn.getThird().length != 0) {
 600                                         // insert into the local block chain
 601                                         validateAndUpdate(sendSlotsReturn.getThird(), true);
 602                                 }
 603                         }
 604                 } catch (ServerException e) {
 605
 606                         System.out.println("Server Failure:   " + e.getType());
 607
 608
 609                         if (e.getType() != ServerException.TypeInputTimeout) {
 610                                 // e.printStackTrace();
 611
 612                                 // Nothing was able to be sent to the server so just clear these data structures
 613                                 for (Transaction transaction : transactionPartsSent.keySet()) {
 614                                         transaction.resetNextPartToSend();
 615
 616                                         // Set the transaction sequence number back to nothing
 617                                         if (!transaction.didSendAPartToServer()) {
 618                                                 transaction.setSequenceNumber(-1);
 619                                         }
 620                                 }
 621                         } else {
 622                                 // There was a partial send to the server
 623                                 hadPartialSendToServer = true;
 624
 625                                 // Nothing was able to be sent to the server so just clear these data structures
 626                                 for (Transaction transaction : transactionPartsSent.keySet()) {
 627                                         transaction.resetNextPartToSend();
 628                                         transaction.setServerFailure();
 629                                 }
 630                         }
 631
 632                         pendingSendArbitrationEntriesToDelete.clear();
 633                         transactionPartsSent.clear();
 634
 635                         throw e;
 636                 }
 637
 638                 return newKey == null;
 639         }
 640
 641         public synchronized boolean updateFromLocal(long machineId) {
 642                 Pair<String, Integer> localCommunicationInformation = localCommunicationTable.get(machineId);
 643                 if (localCommunicationInformation == null) {
 644                         // Cant talk to that device locally so do nothing
 645                         return false;
 646                 }
 647
 648                 // Get the size of the send data
 649                 int sendDataSize = Integer.BYTES + Long.BYTES;
 650
 651                 Long lastArbitrationDataLocalSequenceNumber = (long) - 1;
 652                 if (lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.get(machineId) != null) {
 653                         lastArbitrationDataLocalSequenceNumber = lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.get(machineId);
 654                 }
 655
 656                 byte[] sendData = new byte[sendDataSize];
 657                 ByteBuffer bbEncode = ByteBuffer.wrap(sendData);
 658
 659                 // Encode the data
 660                 bbEncode.putLong(lastArbitrationDataLocalSequenceNumber);
 661                 bbEncode.putInt(0);
 662
 663                 // Send by local
 664                 byte[] returnData = cloud.sendLocalData(sendData, localCommunicationInformation.getFirst(), localCommunicationInformation.getSecond());
 665
 666                 if (returnData == null) {
 667                         // Could not contact server
 668                         return false;
 669                 }
 670
 671                 // Decode the data
 672                 ByteBuffer bbDecode = ByteBuffer.wrap(returnData);
 673                 int numberOfEntries = bbDecode.getInt();
 674
 675                 for (int i = 0; i < numberOfEntries; i++) {
 676                         byte type = bbDecode.get();
 677                         if (type == Entry.TypeAbort) {
 678                                 Abort abort = (Abort)Abort.decode(null, bbDecode);
 679                                 processEntry(abort);
 680                         } else if (type == Entry.TypeCommitPart) {
 681                                 CommitPart commitPart = (CommitPart)CommitPart.decode(null, bbDecode);
 682                                 processEntry(commitPart);
 683                         }
 684                 }
 685
 686                 updateLiveStateFromLocal();
 687
 688                 return true;
 689         }
 690
 691         private Pair<Boolean, Boolean> sendTransactionToLocal(Transaction transaction) {
 692
 693                 // Get the devices local communications
 694                 Pair<String, Integer> localCommunicationInformation = localCommunicationTable.get(transaction.getArbitrator());
 695
 696                 if (localCommunicationInformation == null) {
 697                         // Cant talk to that device locally so do nothing
 698                         return new Pair<Boolean, Boolean>(false, false);
 699                 }
 700
 701                 // Get the size of the send data
 702                 int sendDataSize = Integer.BYTES + Long.BYTES;
 703                 for (TransactionPart part : transaction.getParts().values()) {
 704                         sendDataSize += part.getSize();
 705                 }
 706
 707                 Long lastArbitrationDataLocalSequenceNumber = (long) - 1;
 708                 if (lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.get(transaction.getArbitrator()) != null) {
 709                         lastArbitrationDataLocalSequenceNumber = lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.get(transaction.getArbitrator());
 710                 }
 711
 712                 // Make the send data size
 713                 byte[] sendData = new byte[sendDataSize];
 714                 ByteBuffer bbEncode = ByteBuffer.wrap(sendData);
 715
 716                 // Encode the data
 717                 bbEncode.putLong(lastArbitrationDataLocalSequenceNumber);
 718                 bbEncode.putInt(transaction.getParts().size());
 719                 for (TransactionPart part : transaction.getParts().values()) {
 720                         part.encode(bbEncode);
 721                 }
 722
 723                 // Send by local
 724                 byte[] returnData = cloud.sendLocalData(sendData, localCommunicationInformation.getFirst(), localCommunicationInformation.getSecond());
 725
 726                 if (returnData == null) {
 727                         // Could not contact server
 728                         return new Pair<Boolean, Boolean>(true, false);
 729                 }
 730
 731                 // Decode the data
 732                 ByteBuffer bbDecode = ByteBuffer.wrap(returnData);
 733                 boolean didCommit = bbDecode.get() == 1;
 734                 boolean couldArbitrate = bbDecode.get() == 1;
 735                 int numberOfEntries = bbDecode.getInt();
 736                 boolean foundAbort = false;
 737
 738                 for (int i = 0; i < numberOfEntries; i++) {
 739                         byte type = bbDecode.get();
 740                         if (type == Entry.TypeAbort) {
 741                                 Abort abort = (Abort)Abort.decode(null, bbDecode);
 742
 743                                 if ((abort.getTransactionMachineId() == localMachineId) && (abort.getTransactionClientLocalSequenceNumber() == transaction.getClientLocalSequenceNumber())) {
 744                                         foundAbort = true;
 745                                 }
 746
 747                                 processEntry(abort);
 748                         } else if (type == Entry.TypeCommitPart) {
 749                                 CommitPart commitPart = (CommitPart)CommitPart.decode(null, bbDecode);
 750                                 processEntry(commitPart);
 751                         }
 752                 }
 753
 754                 updateLiveStateFromLocal();
 755
 756                 if (couldArbitrate) {
 757                         TransactionStatus status =  transaction.getTransactionStatus();
 758                         if (didCommit) {
 759                                 status.setStatus(TransactionStatus.StatusCommitted);
 760                         } else {
 761                                 status.setStatus(TransactionStatus.StatusAborted);
 762                         }
 763                 } else {
 764                         TransactionStatus status =  transaction.getTransactionStatus();
 765                         if (foundAbort) {
 766                                 status.setStatus(TransactionStatus.StatusAborted);
 767                         } else {
 768                                 status.setStatus(TransactionStatus.StatusCommitted);
 769                         }
 770                 }
 771
 772                 return new Pair<Boolean, Boolean>(false, true);
 773         }
 774
 775         public synchronized byte[] acceptDataFromLocal(byte[] data) {
 776                 // Decode the data
 777                 ByteBuffer bbDecode = ByteBuffer.wrap(data);
 778                 long lastArbitratedSequenceNumberSeen = bbDecode.getLong();
 779                 int numberOfParts = bbDecode.getInt();
 780
 781                 // If we did commit a transaction or not
 782                 boolean didCommit = false;
 783                 boolean couldArbitrate = false;
 784
 785                 if (numberOfParts != 0) {
 786
 787                         // decode the transaction
 788                         Transaction transaction = new Transaction();
 789                         for (int i = 0; i < numberOfParts; i++) {
 790                                 bbDecode.get();
 791                                 TransactionPart newPart = (TransactionPart)TransactionPart.decode(null, bbDecode);
 792                                 transaction.addPartDecode(newPart);
 793                         }
 794
 795                         // Arbitrate on transaction and pull relevant return data
 796                         Pair<Boolean, Boolean> localArbitrateReturn = arbitrateOnLocalTransaction(transaction);
 797                         couldArbitrate = localArbitrateReturn.getFirst();
 798                         didCommit = localArbitrateReturn.getSecond();
 799
 800                         updateLiveStateFromLocal();
 801
 802                         // Transaction was sent to the server so keep track of it to prevent double commit
 803                         if (transaction.getSequenceNumber() != -1) {
 804                                 offlineTransactionsCommittedAndAtServer.add(transaction.getId());
 805                         }
 806                 }
 807
 808                 // The data to send back
 809                 int returnDataSize = 0;
 810                 List<Entry> unseenArbitrations = new ArrayList<Entry>();
 811
 812                 // Get the aborts to send back
 813                 List<Long> abortLocalSequenceNumbers = new ArrayList<Long >(liveAbortsGeneratedByLocal.keySet());
 814                 Collections.sort(abortLocalSequenceNumbers);
 815                 for (Long localSequenceNumber : abortLocalSequenceNumbers) {
 816                         if (localSequenceNumber <= lastArbitratedSequenceNumberSeen) {
 817                                 continue;
 818                         }
 819
 820                         Abort abort = liveAbortsGeneratedByLocal.get(localSequenceNumber);
 821                         unseenArbitrations.add(abort);
 822                         returnDataSize += abort.getSize();
 823                 }
 824
 825                 // Get the commits to send back
 826                 Map<Long, Commit> commitForClientTable = liveCommitsTable.get(localMachineId);
 827                 if (commitForClientTable != null) {
 828                         List<Long> commitLocalSequenceNumbers = new ArrayList<Long>(commitForClientTable.keySet());
 829                         Collections.sort(commitLocalSequenceNumbers);
 830
 831                         for (Long localSequenceNumber : commitLocalSequenceNumbers) {
 832                                 Commit commit = commitForClientTable.get(localSequenceNumber);
 833
 834                                 if (localSequenceNumber <= lastArbitratedSequenceNumberSeen) {
 835                                         continue;
 836                                 }
 837
 838                                 unseenArbitrations.addAll(commit.getParts().values());
 839
 840                                 for (CommitPart commitPart : commit.getParts().values()) {
 841                                         returnDataSize += commitPart.getSize();
 842                                 }
 843                         }
 844                 }
 845
 846                 // Number of arbitration entries to decode
 847                 returnDataSize += 2 * Integer.BYTES;
 848
 849                 // Boolean of did commit or not
 850                 if (numberOfParts != 0) {
 851                         returnDataSize += Byte.BYTES;
 852                 }
 853
 854                 // Data to send Back
 855                 byte[] returnData = new byte[returnDataSize];
 856                 ByteBuffer bbEncode = ByteBuffer.wrap(returnData);
 857
 858                 if (numberOfParts != 0) {
 859                         if (didCommit) {
 860                                 bbEncode.put((byte)1);
 861                         } else {
 862                                 bbEncode.put((byte)0);
 863                         }
 864                         if (couldArbitrate) {
 865                                 bbEncode.put((byte)1);
 866                         } else {
 867                                 bbEncode.put((byte)0);
 868                         }
 869                 }
 870
 871                 bbEncode.putInt(unseenArbitrations.size());
 872                 for (Entry entry : unseenArbitrations) {
 873                         entry.encode(bbEncode);
 874                 }
 875
 876                 return returnData;
 877         }
 878
 879         private ThreeTuple<Boolean, Boolean, Slot[]> sendSlotsToServer(Slot slot, int newSize, boolean isNewKey)  throws ServerException {
 880
 881                 boolean attemptedToSendToServerTmp = attemptedToSendToServer;
 882                 attemptedToSendToServer = true;
 883
 884                 boolean inserted = false;
 885                 boolean lastTryInserted = false;
 886
 887                 Slot[] array = cloud.putSlot(slot, newSize);
 888                 if (array == null) {
 889                         array = new Slot[] {slot};
 890                         rejectedSlotList.clear();
 891                         inserted = true;
 892                 }       else {
 893                         if (array.length == 0) {
 894                                 throw new Error("Server Error: Did not send any slots");
 895                         }
 896
 897                         // if (attemptedToSendToServerTmp) {
 898                         if (hadPartialSendToServer) {
 899
 900                                 boolean isInserted = false;
 901                                 for (Slot s : array) {
 902                                         if ((s.getSequenceNumber() == slot.getSequenceNumber()) && (s.getMachineID() == localMachineId)) {
 903                                                 isInserted = true;
 904                                                 break;
 905                                         }
 906                                 }
 907
 908                                 for (Slot s : array) {
 909                                         if (isInserted) {
 910                                                 break;
 911                                         }
 912
 913                                         // Process each entry in the slot
 914                                         for (Entry entry : s.getEntries()) {
 915
 916                                                 if (entry.getType() == Entry.TypeLastMessage) {
 917                                                         LastMessage lastMessage = (LastMessage)entry;
 918
 919                                                         if ((lastMessage.getMachineID() == localMachineId) && (lastMessage.getSequenceNumber() == slot.getSequenceNumber())) {
 920                                                                 isInserted = true;
 921                                                                 break;
 922                                                         }
 923                                                 }
 924                                         }
 925                                 }
 926
 927                                 if (!isInserted) {
 928                                         rejectedSlotList.add(slot.getSequenceNumber());
 929                                         lastTryInserted = false;
 930                                 } else {
 931                                         lastTryInserted = true;
 932                                 }
 933                         } else {
 934                                 rejectedSlotList.add(slot.getSequenceNumber());
 935                                 lastTryInserted = false;
 936                         }
 937                 }
 938
 939                 return new ThreeTuple<Boolean, Boolean, Slot[]>(inserted, lastTryInserted, array);
 940         }
 941
 942         /**
 943          * Returns false if a resize was needed
 944          */
 945         private ThreeTuple<Boolean, Integer, Boolean> fillSlot(Slot slot, boolean resize, NewKey newKeyEntry) {
 946                 int newSize = 0;
 947                 if (liveSlotCount > bufferResizeThreshold) {
 948                         resize = true; //Resize is forced
 949                 }
 950
 951                 if (resize) {
 952                         newSize = (int) (numberOfSlots * RESIZE_MULTIPLE);
 953                         TableStatus status = new TableStatus(slot, newSize);
 954                         slot.addEntry(status);
 955                 }
 956
 957                 // Fill with rejected slots first before doing anything else
 958                 doRejectedMessages(slot);
 959
 960                 // Do mandatory rescue of entries
 961                 ThreeTuple<Boolean, Boolean, Long> mandatoryRescueReturn = doMandatoryResuce(slot, resize);
 962
 963                 // Extract working variables
 964                 boolean needsResize = mandatoryRescueReturn.getFirst();
 965                 boolean seenLiveSlot = mandatoryRescueReturn.getSecond();
 966                 long currentRescueSequenceNumber = mandatoryRescueReturn.getThird();
 967
 968                 if (needsResize && !resize) {
 969                         // We need to resize but we are not resizing so return false
 970                         return new ThreeTuple<Boolean, Integer, Boolean>(true, null, null);
 971                 }
 972
 973                 boolean inserted = false;
 974                 if (newKeyEntry != null) {
 975                         newKeyEntry.setSlot(slot);
 976                         if (slot.hasSpace(newKeyEntry)) {
 977                                 slot.addEntry(newKeyEntry);
 978                                 inserted = true;
 979                         }
 980                 }
 981
 982                 // Clear the transactions, aborts and commits that were sent previously
 983                 transactionPartsSent.clear();
 984                 pendingSendArbitrationEntriesToDelete.clear();
 985
 986                 for (ArbitrationRound round : pendingSendArbitrationRounds) {
 987                         boolean isFull = false;
 988                         round.generateParts();
 989                         List<Entry> parts = round.getParts();
 990
 991                         // Insert pending arbitration data
 992                         for (Entry arbitrationData : parts) {
 993
 994                                 // If it is an abort then we need to set some information
 995                                 if (arbitrationData instanceof Abort) {
 996                                         ((Abort)arbitrationData).setSequenceNumber(slot.getSequenceNumber());
 997                                 }
 998
 999                                 if (!slot.hasSpace(arbitrationData)) {
1000                                         // No space so cant do anything else with these data entries
1001                                         isFull = true;
1002                                         break;
1003                                 }
1004
1005                                 // Add to this current slot and add it to entries to delete
1006                                 slot.addEntry(arbitrationData);
1007                                 pendingSendArbitrationEntriesToDelete.add(arbitrationData);
1008                         }
1009
1010                         if (isFull) {
1011                                 break;
1012                         }
1013                 }
1014
1015                 if (pendingTransactionQueue.size() > 0) {
1016
1017                         Transaction transaction = pendingTransactionQueue.get(0);
1018
1019                         // Set the transaction sequence number if it has yet to be inserted into the block chain
1020                         if ((!transaction.didSendAPartToServer() && !transaction.getServerFailure()) || (transaction.getSequenceNumber() == -1)) {
1021                                 transaction.setSequenceNumber(slot.getSequenceNumber());
1022                         }
1023
1024                         while (true) {
1025                                 TransactionPart part = transaction.getNextPartToSend();
1026
1027                                 if (part == null) {
1028                                         // Ran out of parts to send for this transaction so move on
1029                                         break;
1030                                 }
1031
1032                                 if (slot.hasSpace(part)) {
1033                                         slot.addEntry(part);
1034                                         List<Integer> partsSent = transactionPartsSent.get(transaction);
1035                                         if (partsSent == null) {
1036                                                 partsSent = new ArrayList<Integer>();
1037                                                 transactionPartsSent.put(transaction, partsSent);
1038                                         }
1039                                         partsSent.add(part.getPartNumber());
1040                                         transactionPartsSent.put(transaction, partsSent);
1041                                 } else {
1042                                         break;
1043                                 }
1044                         }
1045                 }
1046
1047                 // Fill the remainder of the slot with rescue data
1048                 doOptionalRescue(slot, seenLiveSlot, currentRescueSequenceNumber, resize);
1049
1050                 return new ThreeTuple<Boolean, Integer, Boolean>(false, newSize, inserted);
1051         }
1052
1053         private void doRejectedMessages(Slot s) {
1054                 if (! rejectedSlotList.isEmpty()) {
1055                         /* TODO: We should avoid generating a rejected message entry if
1056                          * there is already a sufficient entry in the queue (e.g.,
1057                          * equalsto value of true and same sequence number).  */
1058
1059                         long old_seqn = rejectedSlotList.firstElement();
1060                         if (rejectedSlotList.size() > REJECTED_THRESHOLD) {
1061                                 long new_seqn = rejectedSlotList.lastElement();
1062                                 RejectedMessage rm = new RejectedMessage(s, localMachineId, old_seqn, new_seqn, false);
1063                                 s.addEntry(rm);
1064                         } else {
1065                                 long prev_seqn = -1;
1066                                 int i = 0;
1067                                 /* Go through list of missing messages */
1068                                 for (; i < rejectedSlotList.size(); i++) {
1069                                         long curr_seqn = rejectedSlotList.get(i);
1070                                         Slot s_msg = buffer.getSlot(curr_seqn);
1071                                         if (s_msg != null)
1072                                                 break;
1073                                         prev_seqn = curr_seqn;
1074                                 }
1075                                 /* Generate rejected message entry for missing messages */
1076                                 if (prev_seqn != -1) {
1077                                         RejectedMessage rm = new RejectedMessage(s, localMachineId, old_seqn, prev_seqn, false);
1078                                         s.addEntry(rm);
1079                                 }
1080                                 /* Generate rejected message entries for present messages */
1081                                 for (; i < rejectedSlotList.size(); i++) {
1082                                         long curr_seqn = rejectedSlotList.get(i);
1083                                         Slot s_msg = buffer.getSlot(curr_seqn);
1084                                         long machineid = s_msg.getMachineID();
1085                                         RejectedMessage rm = new RejectedMessage(s, machineid, curr_seqn, curr_seqn, true);
1086                                         s.addEntry(rm);
1087                                 }
1088                         }
1089                 }
1090         }
1091
1092         private ThreeTuple<Boolean, Boolean, Long> doMandatoryResuce(Slot slot, boolean resize) {
1093                 long newestSequenceNumber = buffer.getNewestSeqNum();
1094                 long oldestSequenceNumber = buffer.getOldestSeqNum();
1095                 if (oldestLiveSlotSequenceNumver < oldestSequenceNumber) {
1096                         oldestLiveSlotSequenceNumver = oldestSequenceNumber;
1097                 }
1098
1099                 long currentSequenceNumber = oldestLiveSlotSequenceNumver;
1100                 boolean seenLiveSlot = false;
1101                 long firstIfFull = newestSequenceNumber + 1 - numberOfSlots;    // smallest seq number in the buffer if it is full
1102                 long threshold = firstIfFull + FREE_SLOTS;      // we want the buffer to be clear of live entries up to this point
1103
1104
1105                 // Mandatory Rescue
1106                 for (; currentSequenceNumber < threshold; currentSequenceNumber++) {
1107                         Slot previousSlot = buffer.getSlot(currentSequenceNumber);
1108                         // Push slot number forward
1109                         if (! seenLiveSlot) {
1110                                 oldestLiveSlotSequenceNumver = currentSequenceNumber;
1111                         }
1112
1113                         if (!previousSlot.isLive()) {
1114                                 continue;
1115                         }
1116
1117                         // We have seen a live slot
1118                         seenLiveSlot = true;
1119
1120                         // Get all the live entries for a slot
1121                         Vector<Entry> liveEntries = previousSlot.getLiveEntries(resize);
1122
1123                         // Iterate over all the live entries and try to rescue them
1124                         for (Entry liveEntry : liveEntries) {
1125                                 if (slot.hasSpace(liveEntry)) {
1126
1127                                         // Enough space to rescue the entry
1128                                         slot.addEntry(liveEntry);
1129                                 } else if (currentSequenceNumber == firstIfFull) {
1130                                         //if there's no space but the entry is about to fall off the queue
1131                                         System.out.println("B"); //?
1132                                         return new ThreeTuple<Boolean, Boolean, Long>(true, seenLiveSlot, currentSequenceNumber);
1133
1134                                 }
1135                         }
1136                 }
1137
1138                 // Did not resize
1139                 return new ThreeTuple<Boolean, Boolean, Long>(false, seenLiveSlot, currentSequenceNumber);
1140         }
1141
1142         private void  doOptionalRescue(Slot s, boolean seenliveslot, long seqn, boolean resize) {
1143                 /* now go through live entries from least to greatest sequence number until
1144                  * either all live slots added, or the slot doesn't have enough room
1145                  * for SKIP_THRESHOLD consecutive entries*/
1146                 int skipcount = 0;
1147                 long newestseqnum = buffer.getNewestSeqNum();
1148                 search:
1149                 for (; seqn <= newestseqnum; seqn++) {
1150                         Slot prevslot = buffer.getSlot(seqn);
1151                         //Push slot number forward
1152                         if (!seenliveslot)
1153                                 oldestLiveSlotSequenceNumver = seqn;
1154
1155                         if (!prevslot.isLive())
1156                                 continue;
1157                         seenliveslot = true;
1158                         Vector<Entry> liveentries = prevslot.getLiveEntries(resize);
1159                         for (Entry liveentry : liveentries) {
1160                                 if (s.hasSpace(liveentry))
1161                                         s.addEntry(liveentry);
1162                                 else {
1163                                         skipcount++;
1164                                         if (skipcount > SKIP_THRESHOLD)
1165                                                 break search;
1166                                 }
1167                         }
1168                 }
1169         }
1170
1171         /**
1172          * Checks for malicious activity and updates the local copy of the block chain.
1173          */
1174         private void validateAndUpdate(Slot[] newSlots, boolean acceptUpdatesToLocal) {
1175
1176                 // The cloud communication layer has checked slot HMACs already before decoding
1177                 if (newSlots.length == 0) {
1178                         return;
1179                 }
1180
1181                 // Reset the table status declared sizes
1182                 smallestTableStatusSeen = -1;
1183                 largestTableStatusSeen = -1;
1184
1185
1186                 // Make sure all slots are newer than the last largest slot this client has seen
1187                 long firstSeqNum = newSlots[0].getSequenceNumber();
1188                 if (firstSeqNum <= sequenceNumber) {
1189                         throw new Error("Server Error: Sent older slots!");
1190                 }
1191
1192                 // Create an object that can access both new slots and slots in our local chain
1193                 // without committing slots to our local chain
1194                 SlotIndexer indexer = new SlotIndexer(newSlots, buffer);
1195
1196                 // Check that the HMAC chain is not broken
1197                 checkHMACChain(indexer, newSlots);
1198
1199                 // Set to keep track of messages from clients
1200                 HashSet<Long> machineSet = new HashSet<Long>(lastMessageTable.keySet());
1201
1202                 // Process each slots data
1203                 for (Slot slot : newSlots) {
1204                         processSlot(indexer, slot, acceptUpdatesToLocal, machineSet);
1205                 }
1206
1207                 // If there is a gap, check to see if the server sent us everything.
1208                 if (firstSeqNum != (sequenceNumber + 1)) {
1209
1210                         // Check the size of the slots that were sent down by the server.
1211                         // Can only check the size if there was a gap
1212                         checkNumSlots(newSlots.length);
1213
1214                         // Since there was a gap every machine must have pushed a slot or must have
1215                         // a last message message.  If not then the server is hiding slots
1216                         if (!machineSet.isEmpty()) {
1217                                 throw new Error("Missing record for machines: " + machineSet);
1218                         }
1219                 }
1220
1221                 // Update the size of our local block chain.
1222                 commitNewMaxSize();
1223
1224                 // Commit new to slots to the local block chain.
1225                 for (Slot slot : newSlots) {
1226
1227                         // Insert this slot into our local block chain copy.
1228                         buffer.putSlot(slot);
1229
1230                         // Keep track of how many slots are currently live (have live data in them).
1231                         liveSlotCount++;
1232                 }
1233
1234                 // Get the sequence number of the latest slot in the system
1235                 sequenceNumber = newSlots[newSlots.length - 1].getSequenceNumber();
1236
1237                 updateLiveStateFromServer();
1238
1239                 // No Need to remember after we pulled from the server
1240                 offlineTransactionsCommittedAndAtServer.clear();
1241
1242                 // This is invalidated now
1243                 hadPartialSendToServer = false;
1244         }
1245
1246         private void updateLiveStateFromServer() {
1247                 // Process the new transaction parts
1248                 processNewTransactionParts();
1249
1250                 // Do arbitration on new transactions that were received
1251                 arbitrateFromServer();
1252
1253                 // Update all the committed keys
1254                 boolean didCommitOrSpeculate = updateCommittedTable();
1255
1256                 // Delete the transactions that are now dead
1257                 updateLiveTransactionsAndStatus();
1258
1259                 // Do speculations
1260                 didCommitOrSpeculate |= updateSpeculativeTable(didCommitOrSpeculate);
1261                 updatePendingTransactionSpeculativeTable(didCommitOrSpeculate);
1262         }
1263
1264         private void updateLiveStateFromLocal() {
1265                 // Update all the committed keys
1266                 boolean didCommitOrSpeculate = updateCommittedTable();
1267
1268                 // Delete the transactions that are now dead
1269                 updateLiveTransactionsAndStatus();
1270
1271                 // Do speculations
1272                 didCommitOrSpeculate |= updateSpeculativeTable(didCommitOrSpeculate);
1273                 updatePendingTransactionSpeculativeTable(didCommitOrSpeculate);
1274         }
1275
1276         /**
1277          * Check the size of the block chain to make sure there are enough slots sent back by the server.
1278          * This is only called when we have a gap between the slots that we have locally and the slots
1279          * sent by the server therefore in the slots sent by the server there will be at least 1 Table
1280          * status message
1281          */
1282         private void checkNumSlots(int numberOfSlots) {
1283
1284                 // We only have 1 size so we must have this many slots
1285                 if (largestTableStatusSeen == smallestTableStatusSeen) {
1286                         if (numberOfSlots != smallestTableStatusSeen) {
1287                                 throw new Error("Server Error: Server did not send all slots.  Expected: " + smallestTableStatusSeen + " Received:" + numberOfSlots);
1288                         }
1289                 } else {
1290                         // We have more than 1
1291                         if (numberOfSlots < smallestTableStatusSeen) {
1292                                 throw new Error("Server Error: Server did not send all slots.  Expected at least: " + smallestTableStatusSeen + " Received:" + numberOfSlots);
1293                         }
1294                 }
1295         }
1296
1297         /**
1298          * Update the size of of the local buffer if it is needed.
1299          */
1300         private void commitNewMaxSize() {
1301
1302                 int currMaxSize = 0;
1303
1304                 if (largestTableStatusSeen == -1) {
1305                         // No table status seen so the current max size does not change
1306                         currMaxSize = numberOfSlots;
1307                 } else {
1308                         currMaxSize = largestTableStatusSeen;
1309                 }
1310
1311                 // Resize the local slot buffer
1312                 if (numberOfSlots != currMaxSize) {
1313                         buffer.resize(currMaxSize);
1314                 }
1315
1316                 // Change the number of local slots to the new size
1317                 numberOfSlots = currMaxSize;
1318
1319                 // Recalculate the resize threshold since the size of the local buffer has changed
1320                 setResizeThreshold();
1321         }
1322
1323         /**
1324          * Process the new transaction parts from this latest round of slots received from the server
1325          */
1326         private void processNewTransactionParts() {
1327
1328                 if (newTransactionParts.size() == 0) {
1329                         // Nothing new to process
1330                         return;
1331                 }
1332
1333                 // Iterate through all the machine Ids that we received new parts for
1334                 for (Long machineId : newTransactionParts.keySet()) {
1335                         Map<Pair<Long, Integer>, TransactionPart> parts = newTransactionParts.get(machineId);
1336
1337                         // Iterate through all the parts for that machine Id
1338                         for (Pair<Long, Integer> partId : parts.keySet()) {
1339                                 TransactionPart part = parts.get(partId);
1340
1341                                 Long lastTransactionNumber = lastArbitratedTransactionNumberByArbitratorTable.get(part.getArbitratorId());
1342                                 if ((lastTransactionNumber != null) && (lastTransactionNumber >= part.getSequenceNumber())) {
1343                                         // Set dead the transaction part
1344                                         part.setDead();
1345                                         continue;
1346                                 }
1347
1348                                 // Get the transaction object for that sequence number
1349                                 Transaction transaction = liveTransactionBySequenceNumberTable.get(part.getSequenceNumber());
1350
1351                                 if (transaction == null) {
1352                                         // This is a new transaction that we dont have so make a new one
1353                                         transaction = new Transaction();
1354
1355                                         // Insert this new transaction into the live tables
1356                                         liveTransactionBySequenceNumberTable.put(part.getSequenceNumber(), transaction);
1357                                         liveTransactionByTransactionIdTable.put(part.getTransactionId(), transaction);
1358                                 }
1359
1360                                 // Add that part to the transaction
1361                                 transaction.addPartDecode(part);
1362                         }
1363                 }
1364
1365                 // Clear all the new transaction parts in preparation for the next time the server sends slots
1366                 newTransactionParts.clear();
1367         }
1368
1369         private void arbitrateFromServer() {
1370
1371                 if (liveTransactionBySequenceNumberTable.size() == 0) {
1372                         // Nothing to arbitrate on so move on
1373                         return;
1374                 }
1375
1376                 // Get the transaction sequence numbers and sort from oldest to newest
1377                 List<Long> transactionSequenceNumbers = new ArrayList<Long>(liveTransactionBySequenceNumberTable.keySet());
1378                 Collections.sort(transactionSequenceNumbers);
1379
1380                 // Collection of key value pairs that are
1381                 Map<IoTString, KeyValue> speculativeTableTmp = new HashMap<IoTString, KeyValue>();
1382
1383                 // The last transaction arbitrated on
1384                 long lastTransactionCommitted = -1;
1385                 Set<Abort> generatedAborts = new HashSet<Abort>();
1386
1387                 for (Long transactionSequenceNumber : transactionSequenceNumbers) {
1388                         Transaction transaction = liveTransactionBySequenceNumberTable.get(transactionSequenceNumber);
1389
1390                         // Check if this machine arbitrates for this transaction if not then we cant arbitrate this transaction
1391                         if (transaction.getArbitrator() != localMachineId) {
1392                                 continue;
1393                         }
1394
1395                         if (offlineTransactionsCommittedAndAtServer.contains(transaction.getId())) {
1396                                 // We have seen this already locally so dont commit again
1397                                 continue;
1398                         }
1399
1400
1401                         if (!transaction.isComplete()) {
1402                                 // Will arbitrate in incorrect order if we continue so just break
1403                                 // Most likely this
1404                                 break;
1405                         }
1406
1407                         // update the largest transaction seen by arbitrator from server
1408                         if (lastTransactionSeenFromMachineFromServer.get(transaction.getMachineId()) == null) {
1409                                 lastTransactionSeenFromMachineFromServer.put(transaction.getMachineId(), transaction.getClientLocalSequenceNumber());
1410                         } else {
1411                                 Long lastTransactionSeenFromMachine = lastTransactionSeenFromMachineFromServer.get(transaction.getMachineId());
1412                                 if (transaction.getClientLocalSequenceNumber() > lastTransactionSeenFromMachine) {
1413                                         lastTransactionSeenFromMachineFromServer.put(transaction.getMachineId(), transaction.getClientLocalSequenceNumber());
1414                                 }
1415                         }
1416
1417                         if (transaction.evaluateGuard(committedKeyValueTable, speculativeTableTmp, null)) {
1418                                 // Guard evaluated as true
1419
1420                                 // Update the local changes so we can make the commit
1421                                 for (KeyValue kv : transaction.getKeyValueUpdateSet()) {
1422                                         speculativeTableTmp.put(kv.getKey(), kv);
1423                                 }
1424
1425                                 // Update what the last transaction committed was for use in batch commit
1426                                 lastTransactionCommitted = transaction.getSequenceNumber();
1427                         } else {
1428                                 // Guard evaluated was false so create abort
1429
1430                                 // Create the abort
1431                                 Abort newAbort = new Abort(null,
1432                                                            transaction.getClientLocalSequenceNumber(),
1433                                                            transaction.getSequenceNumber(),
1434                                                            transaction.getMachineId(),
1435                                                            transaction.getArbitrator(),
1436                                                            localArbitrationSequenceNumber);
1437                                 localArbitrationSequenceNumber++;
1438
1439                                 generatedAborts.add(newAbort);
1440
1441                                 // Insert the abort so we can process
1442                                 processEntry(newAbort);
1443                         }
1444                 }
1445
1446                 Commit newCommit = null;
1447
1448                 // If there is something to commit
1449                 if (speculativeTableTmp.size() != 0) {
1450
1451                         // Create the commit and increment the commit sequence number
1452                         newCommit = new Commit(localArbitrationSequenceNumber, localMachineId, lastTransactionCommitted);
1453                         localArbitrationSequenceNumber++;
1454
1455                         // Add all the new keys to the commit
1456                         for (KeyValue kv : speculativeTableTmp.values()) {
1457                                 newCommit.addKV(kv);
1458                         }
1459
1460                         // create the commit parts
1461                         newCommit.createCommitParts();
1462
1463                         // Append all the commit parts to the end of the pending queue waiting for sending to the server
1464
1465                         // Insert the commit so we can process it
1466                         for (CommitPart commitPart : newCommit.getParts().values()) {
1467                                 processEntry(commitPart);
1468                         }
1469                 }
1470
1471                 if ((newCommit != null) || (generatedAborts.size() > 0)) {
1472                         ArbitrationRound arbitrationRound = new ArbitrationRound(newCommit, generatedAborts);
1473                         pendingSendArbitrationRounds.add(arbitrationRound);
1474
1475                         if (compactArbitrationData()) {
1476                                 ArbitrationRound newArbitrationRound = pendingSendArbitrationRounds.get(pendingSendArbitrationRounds.size() - 1);
1477                                 if (newArbitrationRound.getCommit() != null) {
1478                                         for (CommitPart commitPart : newArbitrationRound.getCommit().getParts().values()) {
1479                                                 processEntry(commitPart);
1480                                         }
1481                                 }
1482                         }
1483                 }
1484         }
1485
1486         private Pair<Boolean, Boolean> arbitrateOnLocalTransaction(Transaction transaction) {
1487
1488                 // Check if this machine arbitrates for this transaction if not then we cant arbitrate this transaction
1489                 if (transaction.getArbitrator() != localMachineId) {
1490                         return new Pair<Boolean, Boolean>(false, false);
1491                 }
1492
1493                 if (!transaction.isComplete()) {
1494                         // Will arbitrate in incorrect order if we continue so just break
1495                         // Most likely this
1496                         return new Pair<Boolean, Boolean>(false, false);
1497                 }
1498
1499                 if (transaction.getMachineId() != localMachineId) {
1500                         // dont do this check for local transactions
1501                         if (lastTransactionSeenFromMachineFromServer.get(transaction.getMachineId()) != null) {
1502                                 if (lastTransactionSeenFromMachineFromServer.get(transaction.getMachineId()) > transaction.getClientLocalSequenceNumber()) {
1503                                         // We've have already seen this from the server
1504                                         return new Pair<Boolean, Boolean>(false, false);
1505                                 }
1506                         }
1507                 }
1508
1509                 if (transaction.evaluateGuard(committedKeyValueTable, null, null)) {
1510                         // Guard evaluated as true
1511
1512                         // Create the commit and increment the commit sequence number
1513                         Commit newCommit = new Commit(localArbitrationSequenceNumber, localMachineId, -1);
1514                         localArbitrationSequenceNumber++;
1515
1516                         // Update the local changes so we can make the commit
1517                         for (KeyValue kv : transaction.getKeyValueUpdateSet()) {
1518                                 newCommit.addKV(kv);
1519                         }
1520
1521                         // create the commit parts
1522                         newCommit.createCommitParts();
1523
1524                         // Append all the commit parts to the end of the pending queue waiting for sending to the server
1525                         ArbitrationRound arbitrationRound = new ArbitrationRound(newCommit, new HashSet<Abort>());
1526                         pendingSendArbitrationRounds.add(arbitrationRound);
1527
1528                         if (compactArbitrationData()) {
1529                                 ArbitrationRound newArbitrationRound = pendingSendArbitrationRounds.get(pendingSendArbitrationRounds.size() - 1);
1530                                 for (CommitPart commitPart : newArbitrationRound.getCommit().getParts().values()) {
1531                                         processEntry(commitPart);
1532                                 }
1533                         } else {
1534                                 // Insert the commit so we can process it
1535                                 for (CommitPart commitPart : newCommit.getParts().values()) {
1536                                         processEntry(commitPart);
1537                                 }
1538                         }
1539
1540                         if (transaction.getMachineId() == localMachineId) {
1541                                 TransactionStatus status = transaction.getTransactionStatus();
1542                                 if (status != null) {
1543                                         status.setStatus(TransactionStatus.StatusCommitted);
1544                                 }
1545                         }
1546
1547                         updateLiveStateFromLocal();
1548                         return new Pair<Boolean, Boolean>(true, true);
1549                 } else {
1550
1551                         if (transaction.getMachineId() == localMachineId) {
1552                                 // For locally created messages update the status
1553
1554                                 // Guard evaluated was false so create abort
1555                                 TransactionStatus status = transaction.getTransactionStatus();
1556                                 if (status != null) {
1557                                         status.setStatus(TransactionStatus.StatusAborted);
1558                                 }
1559                         } else {
1560
1561                                 Set addAbortSet = new HashSet<Abort>();
1562
1563
1564                                 // Create the abort
1565                                 Abort newAbort = new Abort(null,
1566                                                            transaction.getClientLocalSequenceNumber(),
1567                                                            -1,
1568                                                            transaction.getMachineId(),
1569                                                            transaction.getArbitrator(),
1570                                                            localArbitrationSequenceNumber);
1571                                 localArbitrationSequenceNumber++;
1572
1573                                 addAbortSet.add(newAbort);
1574
1575
1576                                 // Append all the commit parts to the end of the pending queue waiting for sending to the server
1577                                 ArbitrationRound arbitrationRound = new ArbitrationRound(null, addAbortSet);
1578                                 pendingSendArbitrationRounds.add(arbitrationRound);
1579
1580                                 if (compactArbitrationData()) {
1581                                         ArbitrationRound newArbitrationRound = pendingSendArbitrationRounds.get(pendingSendArbitrationRounds.size() - 1);
1582                                         for (CommitPart commitPart : newArbitrationRound.getCommit().getParts().values()) {
1583                                                 processEntry(commitPart);
1584                                         }
1585                                 }
1586                         }
1587
1588                         updateLiveStateFromLocal();
1589                         return new Pair<Boolean, Boolean>(true, false);
1590                 }
1591         }
1592
1593         /**
1594          * Compacts the arbitration data my merging commits and aggregating aborts so that a single large push of commits can be done instead of many small updates
1595          */
1596         private boolean compactArbitrationData() {
1597
1598                 if (pendingSendArbitrationRounds.size() < 2) {
1599                         // Nothing to compact so do nothing
1600                         return false;
1601                 }
1602
1603                 ArbitrationRound lastRound = pendingSendArbitrationRounds.get(pendingSendArbitrationRounds.size() - 1);
1604                 if (lastRound.didSendPart()) {
1605                         return false;
1606                 }
1607
1608                 boolean hadCommit = (lastRound.getCommit() == null);
1609                 boolean gotNewCommit = false;
1610
1611                 int numberToDelete = 1;
1612                 while (numberToDelete < pendingSendArbitrationRounds.size()) {
1613                         ArbitrationRound round = pendingSendArbitrationRounds.get(pendingSendArbitrationRounds.size() - numberToDelete - 1);
1614
1615                         if (round.isFull() || round.didSendPart()) {
1616                                 // Stop since there is a part that cannot be compacted and we need to compact in order
1617                                 break;
1618                         }
1619
1620                         if (round.getCommit() == null) {
1621
1622                                 // Try compacting aborts only
1623                                 int newSize = round.getCurrentSize() + lastRound.getAbortsCount();
1624                                 if (newSize > ArbitrationRound.MAX_PARTS) {
1625                                         // Cant compact since it would be too large
1626                                         break;
1627                                 }
1628                                 lastRound.addAborts(round.getAborts());
1629                         } else {
1630
1631                                 // Create a new larger commit
1632                                 Commit newCommit = Commit.merge(lastRound.getCommit(), round.getCommit(), localArbitrationSequenceNumber);
1633                                 localArbitrationSequenceNumber++;
1634
1635                                 // Create the commit parts so that we can count them
1636                                 newCommit.createCommitParts();
1637
1638                                 // Calculate the new size of the parts
1639                                 int newSize = newCommit.getNumberOfParts();
1640                                 newSize += lastRound.getAbortsCount();
1641                                 newSize += round.getAbortsCount();
1642
1643                                 if (newSize > ArbitrationRound.MAX_PARTS) {
1644                                         // Cant compact since it would be too large
1645                                         break;
1646                                 }
1647
1648                                 // Set the new compacted part
1649                                 lastRound.setCommit(newCommit);
1650                                 lastRound.addAborts(round.getAborts());
1651                                 gotNewCommit = true;
1652                         }
1653
1654                         numberToDelete++;
1655                 }
1656
1657                 if (numberToDelete != 1) {
1658                         // If there is a compaction
1659
1660                         // Delete the previous pieces that are now in the new compacted piece
1661                         if (numberToDelete == pendingSendArbitrationRounds.size()) {
1662                                 pendingSendArbitrationRounds.clear();
1663                         } else {
1664                                 for (int i = 0; i < numberToDelete; i++) {
1665                                         pendingSendArbitrationRounds.remove(pendingSendArbitrationRounds.size() - 1);
1666                                 }
1667                         }
1668
1669                         // Add the new compacted into the pending to send list
1670                         pendingSendArbitrationRounds.add(lastRound);
1671
1672                         // Should reinsert into the commit processor
1673                         if (hadCommit && gotNewCommit) {
1674                                 return true;
1675                         }
1676                 }
1677
1678                 return false;
1679         }
1680         // private boolean compactArbitrationData() {
1681         //      return false;
1682         // }
1683
1684         /**
1685          * Update all the commits and the committed tables, sets dead the dead transactions
1686          */
1687         private boolean updateCommittedTable() {
1688
1689                 if (newCommitParts.size() == 0) {
1690                         // Nothing new to process
1691                         return false;
1692                 }
1693
1694                 // Iterate through all the machine Ids that we received new parts for
1695                 for (Long machineId : newCommitParts.keySet()) {
1696                         Map<Pair<Long, Integer>, CommitPart> parts = newCommitParts.get(machineId);
1697
1698                         // Iterate through all the parts for that machine Id
1699                         for (Pair<Long, Integer> partId : parts.keySet()) {
1700                                 CommitPart part = parts.get(partId);
1701
1702                                 // Get the transaction object for that sequence number
1703                                 Map<Long, Commit> commitForClientTable = liveCommitsTable.get(part.getMachineId());
1704
1705                                 if (commitForClientTable == null) {
1706                                         // This is the first commit from this device
1707                                         commitForClientTable = new HashMap<Long, Commit>();
1708                                         liveCommitsTable.put(part.getMachineId(), commitForClientTable);
1709                                 }
1710
1711                                 Commit commit = commitForClientTable.get(part.getSequenceNumber());
1712
1713                                 if (commit == null) {
1714                                         // This is a new commit that we dont have so make a new one
1715                                         commit = new Commit();
1716
1717                                         // Insert this new commit into the live tables
1718                                         commitForClientTable.put(part.getSequenceNumber(), commit);
1719                                 }
1720
1721                                 // Add that part to the commit
1722                                 commit.addPartDecode(part);
1723                         }
1724                 }
1725
1726                 // Clear all the new commits parts in preparation for the next time the server sends slots
1727                 newCommitParts.clear();
1728
1729                 // If we process a new commit keep track of it for future use
1730                 boolean didProcessANewCommit = false;
1731
1732                 // Process the commits one by one
1733                 for (Long arbitratorId : liveCommitsTable.keySet()) {
1734
1735                         // Get all the commits for a specific arbitrator
1736                         Map<Long, Commit> commitForClientTable = liveCommitsTable.get(arbitratorId);
1737
1738                         // Sort the commits in order
1739                         List<Long> commitSequenceNumbers = new ArrayList<Long>(commitForClientTable.keySet());
1740                         Collections.sort(commitSequenceNumbers);
1741
1742                         // Get the last commit seen from this arbitrator
1743                         long lastCommitSeenSequenceNumber = -1;
1744                         if (lastCommitSeenSequenceNumberByArbitratorTable.get(arbitratorId) != null) {
1745                                 lastCommitSeenSequenceNumber = lastCommitSeenSequenceNumberByArbitratorTable.get(arbitratorId);
1746                         }
1747
1748                         // Go through each new commit one by one
1749                         for (int i = 0; i < commitSequenceNumbers.size(); i++) {
1750                                 Long commitSequenceNumber = commitSequenceNumbers.get(i);
1751                                 Commit commit = commitForClientTable.get(commitSequenceNumber);
1752
1753                                 // Special processing if a commit is not complete
1754                                 if (!commit.isComplete()) {
1755                                         if (i == (commitSequenceNumbers.size() - 1)) {
1756                                                 // If there is an incomplete commit and this commit is the latest one seen then this commit cannot be processed and there are no other commits
1757                                                 break;
1758                                         } else {
1759                                                 // This is a commit that was already dead but parts of it are still in the block chain (not flushed out yet).
1760                                                 // Delete it and move on
1761                                                 commit.setDead();
1762                                                 commitForClientTable.remove(commit.getSequenceNumber());
1763                                                 continue;
1764                                         }
1765                                 }
1766
1767                                 // Update the last arbitration data that we have seen so far
1768                                 if (lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.get(commit.getMachineId()) != null) {
1769
1770                                         long lastArbitrationSequenceNumber = lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.get(commit.getMachineId());
1771                                         if (commit.getSequenceNumber() > lastArbitrationSequenceNumber) {
1772                                                 // Is larger
1773                                                 lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.put(commit.getMachineId(), commit.getSequenceNumber());
1774                                         }
1775                                 } else {
1776                                         // Never seen any data from this arbitrator so record the first one
1777                                         lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.put(commit.getMachineId(), commit.getSequenceNumber());
1778                                 }
1779
1780                                 // We have already seen this commit before so need to do the full processing on this commit
1781                                 if (commit.getSequenceNumber() <= lastCommitSeenSequenceNumber) {
1782
1783                                         // Update the last transaction that was updated if we can
1784                                         if (commit.getTransactionSequenceNumber() != -1) {
1785                                                 Long lastTransactionNumber = lastArbitratedTransactionNumberByArbitratorTable.get(commit.getMachineId());
1786
1787                                                 // Update the last transaction sequence number that the arbitrator arbitrated on
1788                                                 if ((lastTransactionNumber == null) || (lastTransactionNumber < commit.getTransactionSequenceNumber())) {
1789                                                         lastArbitratedTransactionNumberByArbitratorTable.put(commit.getMachineId(), commit.getTransactionSequenceNumber());
1790                                                 }
1791                                         }
1792
1793                                         continue;
1794                                 }
1795
1796                                 // If we got here then this is a brand new commit and needs full processing
1797
1798                                 // Get what commits should be edited, these are the commits that have live values for their keys
1799                                 Set<Commit> commitsToEdit = new HashSet<Commit>();
1800                                 for (KeyValue kv : commit.getKeyValueUpdateSet()) {
1801                                         commitsToEdit.add(liveCommitsByKeyTable.get(kv.getKey()));
1802                                 }
1803                                 commitsToEdit.remove(null); // remove null since it could be in this set
1804
1805                                 // Update each previous commit that needs to be updated
1806                                 for (Commit previousCommit : commitsToEdit) {
1807
1808                                         // Only bother with live commits (TODO: Maybe remove this check)
1809                                         if (previousCommit.isLive()) {
1810
1811                                                 // Update which keys in the old commits are still live
1812                                                 for (KeyValue kv : commit.getKeyValueUpdateSet()) {
1813                                                         previousCommit.invalidateKey(kv.getKey());
1814                                                 }
1815
1816                                                 // if the commit is now dead then remove it
1817                                                 if (!previousCommit.isLive()) {
1818                                                         commitForClientTable.remove(previousCommit);
1819                                                 }
1820                                         }
1821                                 }
1822
1823                                 // Update the last seen sequence number from this arbitrator
1824                                 if (lastCommitSeenSequenceNumberByArbitratorTable.get(commit.getMachineId()) != null) {
1825                                         if (commit.getSequenceNumber() > lastCommitSeenSequenceNumberByArbitratorTable.get(commit.getMachineId())) {
1826                                                 lastCommitSeenSequenceNumberByArbitratorTable.put(commit.getMachineId(), commit.getSequenceNumber());
1827                                         }
1828                                 } else {
1829                                         lastCommitSeenSequenceNumberByArbitratorTable.put(commit.getMachineId(), commit.getSequenceNumber());
1830                                 }
1831
1832
1833
1834                                 // Update the last transaction that was updated if we can
1835                                 if (commit.getTransactionSequenceNumber() != -1) {
1836                                         Long lastTransactionNumber = lastArbitratedTransactionNumberByArbitratorTable.get(commit.getMachineId());
1837
1838                                         // Update the last transaction sequence number that the arbitrator arbitrated on
1839                                         if ((lastTransactionNumber == null) || (lastTransactionNumber < commit.getTransactionSequenceNumber())) {
1840                                                 lastArbitratedTransactionNumberByArbitratorTable.put(commit.getMachineId(), commit.getTransactionSequenceNumber());
1841                                         }
1842                                 }
1843
1844                                 // We processed a new commit that we havent seen before
1845                                 didProcessANewCommit = true;
1846
1847
1848
1849                                 // Update the committed table of keys and which commit is using which key
1850                                 for (KeyValue kv : commit.getKeyValueUpdateSet()) {
1851                                         committedKeyValueTable.put(kv.getKey(), kv);
1852                                         liveCommitsByKeyTable.put(kv.getKey(), commit);
1853                                 }
1854                         }
1855                 }
1856
1857                 return didProcessANewCommit;
1858         }
1859
1860         /**
1861          * Create the speculative table from transactions that are still live and have come from the cloud
1862          */
1863         private boolean updateSpeculativeTable(boolean didProcessNewCommits) {
1864                 if (liveTransactionBySequenceNumberTable.keySet().size() == 0) {
1865                         // There is nothing to speculate on
1866                         return false;
1867                 }
1868
1869                 // Create a list of the transaction sequence numbers and sort them from oldest to newest
1870                 List<Long> transactionSequenceNumbersSorted = new ArrayList<Long>(liveTransactionBySequenceNumberTable.keySet());
1871                 Collections.sort(transactionSequenceNumbersSorted);
1872
1873                 boolean hasGapInTransactionSequenceNumbers = transactionSequenceNumbersSorted.get(0) != oldestTransactionSequenceNumberSpeculatedOn;
1874
1875
1876                 if (hasGapInTransactionSequenceNumbers || didProcessNewCommits) {
1877                         // If there is a gap in the transaction sequence numbers then there was a commit or an abort of a transaction
1878                         // OR there was a new commit (Could be from offline commit) so a redo the speculation from scratch
1879
1880                         // Start from scratch
1881                         speculatedKeyValueTable.clear();
1882                         lastTransactionSequenceNumberSpeculatedOn = -1;
1883                         oldestTransactionSequenceNumberSpeculatedOn = -1;
1884
1885                 }
1886
1887                 // Remember the front of the transaction list
1888                 oldestTransactionSequenceNumberSpeculatedOn = transactionSequenceNumbersSorted.get(0);
1889
1890                 // Find where to start arbitration from
1891                 int startIndex = transactionSequenceNumbersSorted.indexOf(lastTransactionSequenceNumberSpeculatedOn) + 1;
1892
1893                 if (startIndex >= transactionSequenceNumbersSorted.size()) {
1894                         // Make sure we are not out of bounds
1895                         return false; // did not speculate
1896                 }
1897
1898                 Set<Long> incompleteTransactionArbitrator = new HashSet<Long>();
1899                 boolean didSkip = true;
1900
1901                 for (int i = startIndex; i < transactionSequenceNumbersSorted.size(); i++) {
1902                         long transactionSequenceNumber = transactionSequenceNumbersSorted.get(i);
1903                         Transaction transaction = liveTransactionBySequenceNumberTable.get(transactionSequenceNumber);
1904
1905                         if (!transaction.isComplete()) {
1906                                 // If there is an incomplete transaction then there is nothing we can do
1907                                 // add this transactions arbitrator to the list of arbitrators we should ignore
1908                                 incompleteTransactionArbitrator.add(transaction.getArbitrator());
1909                                 didSkip = true;
1910                                 continue;
1911                         }
1912
1913                         if (incompleteTransactionArbitrator.contains(transaction.getArbitrator())) {
1914                                 continue;
1915                         }
1916
1917                         lastTransactionSequenceNumberSpeculatedOn = transactionSequenceNumber;
1918
1919                         if (transaction.evaluateGuard(committedKeyValueTable, speculatedKeyValueTable, null)) {
1920                                 // Guard evaluated to true so update the speculative table
1921                                 for (KeyValue kv : transaction.getKeyValueUpdateSet()) {
1922                                         speculatedKeyValueTable.put(kv.getKey(), kv);
1923                                 }
1924                         }
1925                 }
1926
1927                 if (didSkip) {
1928                         // Since there was a skip we need to redo the speculation next time around
1929                         lastTransactionSequenceNumberSpeculatedOn = -1;
1930                         oldestTransactionSequenceNumberSpeculatedOn = -1;
1931                 }
1932
1933                 // We did some speculation
1934                 return true;
1935         }
1936
1937         /**
1938          * Create the pending transaction speculative table from transactions that are still in the pending transaction buffer
1939          */
1940         private void updatePendingTransactionSpeculativeTable(boolean didProcessNewCommitsOrSpeculate) {
1941                 if (pendingTransactionQueue.size() == 0) {
1942                         // There is nothing to speculate on
1943                         return;
1944                 }
1945
1946
1947                 if (didProcessNewCommitsOrSpeculate || (firstPendingTransaction != pendingTransactionQueue.get(0))) {
1948                         // need to reset on the pending speculation
1949                         lastPendingTransactionSpeculatedOn = null;
1950                         firstPendingTransaction = pendingTransactionQueue.get(0);
1951                         pendingTransactionSpeculatedKeyValueTable.clear();
1952                 }
1953
1954                 // Find where to start arbitration from
1955                 int startIndex = pendingTransactionQueue.indexOf(firstPendingTransaction) + 1;
1956
1957                 if (startIndex >= pendingTransactionQueue.size()) {
1958                         // Make sure we are not out of bounds
1959                         return;
1960                 }
1961
1962                 for (int i = startIndex; i < pendingTransactionQueue.size(); i++) {
1963                         Transaction transaction = pendingTransactionQueue.get(i);
1964
1965                         lastPendingTransactionSpeculatedOn = transaction;
1966
1967                         if (transaction.evaluateGuard(committedKeyValueTable, speculatedKeyValueTable, pendingTransactionSpeculatedKeyValueTable)) {
1968                                 // Guard evaluated to true so update the speculative table
1969                                 for (KeyValue kv : transaction.getKeyValueUpdateSet()) {
1970                                         pendingTransactionSpeculatedKeyValueTable.put(kv.getKey(), kv);
1971                                 }
1972                         }
1973                 }
1974         }
1975
1976         /**
1977          * Set dead and remove from the live transaction tables the transactions that are dead
1978          */
1979         private void updateLiveTransactionsAndStatus() {
1980
1981                 // Go through each of the transactions
1982                 for (Iterator<Map.Entry<Long, Transaction>> iter = liveTransactionBySequenceNumberTable.entrySet().iterator(); iter.hasNext();) {
1983                         Transaction transaction = iter.next().getValue();
1984
1985                         // Check if the transaction is dead
1986                         Long lastTransactionNumber = lastArbitratedTransactionNumberByArbitratorTable.get(transaction.getArbitrator());
1987                         if ((lastTransactionNumber != null) && (lastTransactionNumber >= transaction.getSequenceNumber())) {
1988
1989                                 // Set dead the transaction
1990                                 transaction.setDead();
1991
1992                                 // Remove the transaction from the live table
1993                                 iter.remove();
1994                                 liveTransactionByTransactionIdTable.remove(transaction.getId());
1995                         }
1996                 }
1997
1998                 // Go through each of the transactions
1999                 for (Iterator<Map.Entry<Long, TransactionStatus>> iter = outstandingTransactionStatus.entrySet().iterator(); iter.hasNext();) {
2000                         TransactionStatus status = iter.next().getValue();
2001
2002                         // Check if the transaction is dead
2003                         Long lastTransactionNumber = lastArbitratedTransactionNumberByArbitratorTable.get(status.getTransactionArbitrator());
2004                         if ((lastTransactionNumber != null) && (lastTransactionNumber >= status.getTransactionSequenceNumber())) {
2005
2006                                 // Set committed
2007                                 status.setStatus(TransactionStatus.StatusCommitted);
2008
2009                                 // Remove
2010                                 iter.remove();
2011                         }
2012                 }
2013         }
2014
2015         /**
2016          * Process this slot, entry by entry.  Also update the latest message sent by slot
2017          */
2018         private void processSlot(SlotIndexer indexer, Slot slot, boolean acceptUpdatesToLocal, HashSet<Long> machineSet) {
2019
2020                 // Update the last message seen
2021                 updateLastMessage(slot.getMachineID(), slot.getSequenceNumber(), slot, acceptUpdatesToLocal, machineSet);
2022
2023                 // Process each entry in the slot
2024                 for (Entry entry : slot.getEntries()) {
2025                         switch (entry.getType()) {
2026
2027                         case Entry.TypeCommitPart:
2028                                 processEntry((CommitPart)entry);
2029                                 break;
2030
2031                         case Entry.TypeAbort:
2032                                 processEntry((Abort)entry);
2033                                 break;
2034
2035                         case Entry.TypeTransactionPart:
2036                                 processEntry((TransactionPart)entry);
2037                                 break;
2038
2039                         case Entry.TypeNewKey:
2040                                 processEntry((NewKey)entry);
2041                                 break;
2042
2043                         case Entry.TypeLastMessage:
2044                                 processEntry((LastMessage)entry, machineSet);
2045                                 break;
2046
2047                         case Entry.TypeRejectedMessage:
2048                                 processEntry((RejectedMessage)entry, indexer);
2049                                 break;
2050
2051                         case Entry.TypeTableStatus:
2052                                 processEntry((TableStatus)entry);
2053                                 break;
2054
2055                         default:
2056                                 throw new Error("Unrecognized type: " + entry.getType());
2057                         }
2058                 }
2059         }
2060
2061         /**
2062          * Update the last message that was sent for a machine Id
2063          */
2064         private void processEntry(LastMessage entry, HashSet<Long> machineSet) {
2065                 // Update what the last message received by a machine was
2066                 updateLastMessage(entry.getMachineID(), entry.getSequenceNumber(), entry, false, machineSet);
2067         }
2068
2069         /**
2070          * Add the new key to the arbitrators table and update the set of live new keys (in case of a rescued new key message)
2071          */
2072         private void processEntry(NewKey entry) {
2073
2074                 // Update the arbitrator table with the new key information
2075                 arbitratorTable.put(entry.getKey(), entry.getMachineID());
2076
2077                 // Update what the latest live new key is
2078                 NewKey oldNewKey = liveNewKeyTable.put(entry.getKey(), entry);
2079                 if (oldNewKey != null) {
2080                         // Delete the old new key messages
2081                         oldNewKey.setDead();
2082                 }
2083         }
2084
2085         /**
2086          * Process new table status entries and set dead the old ones as new ones come in.
2087          * keeps track of the largest and smallest table status seen in this current round
2088          * of updating the local copy of the block chain
2089          */
2090         private void processEntry(TableStatus entry) {
2091                 int newNumSlots = entry.getMaxSlots();
2092
2093                 if (liveTableStatus != null) {
2094                         // We have a larger table status so the old table status is no longer alive
2095                         liveTableStatus.setDead();
2096                 }
2097
2098                 // Make this new table status the latest alive table status
2099                 liveTableStatus = entry;
2100
2101                 if ((smallestTableStatusSeen == -1) || (newNumSlots < smallestTableStatusSeen)) {
2102                         smallestTableStatusSeen = newNumSlots;
2103                 }
2104
2105                 if ((largestTableStatusSeen == -1) || (newNumSlots > largestTableStatusSeen)) {
2106                         largestTableStatusSeen = newNumSlots;
2107                 }
2108         }
2109
2110         /**
2111          * Check old messages to see if there is a block chain violation. Also
2112          */
2113         private void processEntry(RejectedMessage entry, SlotIndexer indexer) {
2114                 long oldSeqNum = entry.getOldSeqNum();
2115                 long newSeqNum = entry.getNewSeqNum();
2116                 boolean isequal = entry.getEqual();
2117                 long machineId = entry.getMachineID();
2118
2119
2120                 // Check if we have messages that were supposed to be rejected in our local block chain
2121                 for (long seqNum = oldSeqNum; seqNum <= newSeqNum; seqNum++) {
2122
2123                         // Get the slot
2124                         Slot slot = indexer.getSlot(seqNum);
2125
2126                         if (slot != null) {
2127                                 // If we have this slot make sure that it was not supposed to be a rejected slot
2128
2129                                 long slotMachineId = slot.getMachineID();
2130                                 if (isequal != (slotMachineId == machineId)) {
2131                                         throw new Error("Server Error: Trying to insert rejected message for slot " + seqNum);
2132                                 }
2133                         }
2134                 }
2135
2136
2137                 // Create a list of clients to watch until they see this rejected message entry.
2138                 HashSet<Long> deviceWatchSet = new HashSet<Long>();
2139                 for (Map.Entry<Long, Pair<Long, Liveness>> lastMessageEntry : lastMessageTable.entrySet()) {
2140
2141                         // Machine ID for the last message entry
2142                         long lastMessageEntryMachineId = lastMessageEntry.getKey();
2143
2144                         // We've seen it, don't need to continue to watch.  Our next
2145                         // message will implicitly acknowledge it.
2146                         if (lastMessageEntryMachineId == localMachineId) {
2147                                 continue;
2148                         }
2149
2150                         Pair<Long, Liveness> lastMessageValue = lastMessageEntry.getValue();
2151                         long entrySequenceNumber = lastMessageValue.getFirst();
2152
2153                         if (entrySequenceNumber < newSeqNum) {
2154
2155                                 // Add this rejected message to the set of messages that this machine ID did not see yet
2156                                 addWatchList(lastMessageEntryMachineId, entry);
2157
2158                                 // This client did not see this rejected message yet so add it to the watch set to monitor
2159                                 deviceWatchSet.add(lastMessageEntryMachineId);
2160                         }
2161                 }
2162
2163                 if (deviceWatchSet.isEmpty()) {
2164                         // This rejected message has been seen by all the clients so
2165                         entry.setDead();
2166                 } else {
2167                         // We need to watch this rejected message
2168                         entry.setWatchSet(deviceWatchSet);
2169                 }
2170         }
2171
2172         /**
2173          * Check if this abort is live, if not then save it so we can kill it later.
2174          * update the last transaction number that was arbitrated on.
2175          */
2176         private void processEntry(Abort entry) {
2177
2178
2179                 if (entry.getTransactionSequenceNumber() != -1) {
2180                         // update the transaction status if it was sent to the server
2181                         TransactionStatus status = outstandingTransactionStatus.remove(entry.getTransactionSequenceNumber());
2182                         if (status != null) {
2183                                 status.setStatus(TransactionStatus.StatusAborted);
2184                         }
2185                 }
2186
2187                 // Abort has not been seen by the client it is for yet so we need to keep track of it
2188                 Abort previouslySeenAbort = liveAbortTable.put(entry.getAbortId(), entry);
2189                 if (previouslySeenAbort != null) {
2190                         previouslySeenAbort.setDead(); // Delete old version of the abort since we got a rescued newer version
2191                 }
2192
2193                 if (entry.getTransactionArbitrator() == localMachineId) {
2194                         liveAbortsGeneratedByLocal.put(entry.getArbitratorLocalSequenceNumber(), entry);
2195                 }
2196
2197                 if ((entry.getSequenceNumber() != -1) && (lastMessageTable.get(entry.getTransactionMachineId()).getFirst() >= entry.getSequenceNumber())) {
2198
2199                         // The machine already saw this so it is dead
2200                         entry.setDead();
2201                         liveAbortTable.remove(entry.getAbortId());
2202
2203                         if (entry.getTransactionArbitrator() == localMachineId) {
2204                                 liveAbortsGeneratedByLocal.remove(entry.getArbitratorLocalSequenceNumber());
2205                         }
2206
2207                         return;
2208                 }
2209
2210
2211
2212
2213                 // Update the last arbitration data that we have seen so far
2214                 if (lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.get(entry.getTransactionArbitrator()) != null) {
2215
2216                         long lastArbitrationSequenceNumber = lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.get(entry.getTransactionArbitrator());
2217                         if (entry.getSequenceNumber() > lastArbitrationSequenceNumber) {
2218                                 // Is larger
2219                                 lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.put(entry.getTransactionArbitrator(), entry.getSequenceNumber());
2220                         }
2221                 } else {
2222                         // Never seen any data from this arbitrator so record the first one
2223                         lastArbitrationDataLocalSequenceNumberSeenFromArbitrator.put(entry.getTransactionArbitrator(), entry.getSequenceNumber());
2224                 }
2225
2226
2227                 // Set dead a transaction if we can
2228                 Transaction transactionToSetDead = liveTransactionByTransactionIdTable.remove(new Pair<Long, Long>(entry.getTransactionMachineId(), entry.getTransactionClientLocalSequenceNumber()));
2229                 if (transactionToSetDead != null) {
2230                         liveTransactionBySequenceNumberTable.remove(transactionToSetDead.getSequenceNumber());
2231                 }
2232
2233                 // Update the last transaction sequence number that the arbitrator arbitrated on
2234                 Long lastTransactionNumber = lastArbitratedTransactionNumberByArbitratorTable.get(entry.getTransactionArbitrator());
2235                 if ((lastTransactionNumber == null) || (lastTransactionNumber < entry.getTransactionSequenceNumber())) {
2236
2237                         // Is a valid one
2238                         if (entry.getTransactionSequenceNumber() != -1) {
2239                                 lastArbitratedTransactionNumberByArbitratorTable.put(entry.getTransactionArbitrator(), entry.getTransactionSequenceNumber());
2240                         }
2241                 }
2242         }
2243
2244         /**
2245          * Set dead the transaction part if that transaction is dead and keep track of all new parts
2246          */
2247         private void processEntry(TransactionPart entry) {
2248                 // Check if we have already seen this transaction and set it dead OR if it is not alive
2249                 Long lastTransactionNumber = lastArbitratedTransactionNumberByArbitratorTable.get(entry.getArbitratorId());
2250                 if ((lastTransactionNumber != null) && (lastTransactionNumber >= entry.getSequenceNumber())) {
2251                         // This transaction is dead, it was already committed or aborted
2252                         entry.setDead();
2253                         return;
2254                 }
2255
2256                 // This part is still alive
2257                 Map<Pair<Long, Integer>, TransactionPart> transactionPart = newTransactionParts.get(entry.getMachineId());
2258
2259                 if (transactionPart == null) {
2260                         // Dont have a table for this machine Id yet so make one
2261                         transactionPart = new HashMap<Pair<Long, Integer>, TransactionPart>();
2262                         newTransactionParts.put(entry.getMachineId(), transactionPart);
2263                 }
2264
2265                 // Update the part and set dead ones we have already seen (got a rescued version)
2266                 TransactionPart previouslySeenPart = transactionPart.put(entry.getPartId(), entry);
2267                 if (previouslySeenPart != null) {
2268                         previouslySeenPart.setDead();
2269                 }
2270         }
2271
2272         /**
2273          * Process new commit entries and save them for future use.  Delete duplicates
2274          */
2275         private void processEntry(CommitPart entry) {
2276                 Map<Pair<Long, Integer>, CommitPart> commitPart = newCommitParts.get(entry.getMachineId());
2277
2278                 if (commitPart == null) {
2279                         // Don't have a table for this machine Id yet so make one
2280                         commitPart = new HashMap<Pair<Long, Integer>, CommitPart>();
2281                         newCommitParts.put(entry.getMachineId(), commitPart);
2282                 }
2283
2284                 // Update the part and set dead ones we have already seen (got a rescued version)
2285                 CommitPart previouslySeenPart = commitPart.put(entry.getPartId(), entry);
2286                 if (previouslySeenPart != null) {
2287                         previouslySeenPart.setDead();
2288                 }
2289         }
2290
2291         /**
2292          * Update the last message seen table.  Update and set dead the appropriate RejectedMessages as clients see them.
2293          * Updates the live aborts, removes those that are dead and sets them dead.
2294          * Check that the last message seen is correct and that there is no mismatch of our own last message or that
2295          * other clients have not had a rollback on the last message.
2296          */
2297         private void updateLastMessage(long machineId, long seqNum, Liveness liveness, boolean acceptUpdatesToLocal, HashSet<Long> machineSet) {
2298
2299                 // We have seen this machine ID
2300                 machineSet.remove(machineId);
2301
2302                 // Get the set of rejected messages that this machine Id is has not seen yet
2303                 HashSet<RejectedMessage> watchset = rejectedMessageWatchListTable.get(machineId);
2304
2305                 // If there is a rejected message that this machine Id has not seen yet
2306                 if (watchset != null) {
2307
2308                         // Go through each rejected message that this machine Id has not seen yet
2309                         for (Iterator<RejectedMessage> rmit = watchset.iterator(); rmit.hasNext(); ) {
2310
2311                                 RejectedMessage rm = rmit.next();
2312
2313                                 // If this machine Id has seen this rejected message...
2314                                 if (rm.getNewSeqNum() <= seqNum) {
2315
2316                                         // Remove it from our watchlist
2317                                         rmit.remove();
2318
2319                                         // Decrement machines that need to see this notification
2320                                         rm.removeWatcher(machineId);
2321                                 }
2322                         }
2323                 }
2324
2325                 // Set dead the abort
2326                 for (Iterator<Map.Entry<Pair<Long, Long>, Abort>> i = liveAbortTable.entrySet().iterator(); i.hasNext();) {
2327                         Abort abort = i.next().getValue();
2328
2329                         if ((abort.getTransactionMachineId() == machineId) && (abort.getSequenceNumber() <= seqNum)) {
2330                                 abort.setDead();
2331                                 i.remove();
2332
2333                                 if (abort.getTransactionArbitrator() == localMachineId) {
2334                                         liveAbortsGeneratedByLocal.remove(abort.getArbitratorLocalSequenceNumber());
2335                                 }
2336                         }
2337                 }
2338
2339
2340
2341                 if (machineId == localMachineId) {
2342                         // Our own messages are immediately dead.
2343                         if (liveness instanceof LastMessage) {
2344                                 ((LastMessage)liveness).setDead();
2345                         } else if (liveness instanceof Slot) {
2346                                 ((Slot)liveness).setDead();
2347                         } else {
2348                                 throw new Error("Unrecognized type");
2349                         }
2350                 }
2351
2352                 // Get the old last message for this device
2353                 Pair<Long, Liveness> lastMessageEntry = lastMessageTable.put(machineId, new Pair<Long, Liveness>(seqNum, liveness));
2354                 if (lastMessageEntry == null) {
2355                         // If no last message then there is nothing else to process
2356                         return;
2357                 }
2358
2359                 long lastMessageSeqNum = lastMessageEntry.getFirst();
2360                 Liveness lastEntry = lastMessageEntry.getSecond();
2361
2362                 // If it is not our machine Id since we already set ours to dead
2363                 if (machineId != localMachineId) {
2364                         if (lastEntry instanceof LastMessage) {
2365                                 ((LastMessage)lastEntry).setDead();
2366                         } else if (lastEntry instanceof Slot) {
2367                                 ((Slot)lastEntry).setDead();
2368                         } else {
2369                                 throw new Error("Unrecognized type");
2370                         }
2371                 }
2372
2373                 // Make sure the server is not playing any games
2374                 if (machineId == localMachineId) {
2375
2376                         if (hadPartialSendToServer) {
2377                                 // We were not making any updates and we had a machine mismatch
2378                                 if (lastMessageSeqNum > seqNum && !acceptUpdatesToLocal) {
2379                                         throw new Error("Server Error: Mismatch on local machine sequence number, needed at least: " +  lastMessageSeqNum  + " got: " + seqNum);
2380                                 }
2381
2382                         } else {
2383                                 // We were not making any updates and we had a machine mismatch
2384                                 if (lastMessageSeqNum != seqNum && !acceptUpdatesToLocal) {
2385                                         throw new Error("Server Error: Mismatch on local machine sequence number, needed: " +  lastMessageSeqNum + " got: " + seqNum);
2386                                 }
2387                         }
2388                 } else {
2389                         if (lastMessageSeqNum > seqNum) {
2390                                 throw new Error("Server Error: Rollback on remote machine sequence number");
2391                         }
2392                 }
2393         }
2394
2395         /**
2396          * Add a rejected message entry to the watch set to keep track of which clients have seen that
2397          * rejected message entry and which have not.
2398          */
2399         private void addWatchList(long machineId, RejectedMessage entry) {
2400                 HashSet<RejectedMessage> entries = rejectedMessageWatchListTable.get(machineId);
2401                 if (entries == null) {
2402                         // There is no set for this machine ID yet so create one
2403                         entries = new HashSet<RejectedMessage>();
2404                         rejectedMessageWatchListTable.put(machineId, entries);
2405                 }
2406                 entries.add(entry);
2407         }
2408
2409         /**
2410          * Check if the HMAC chain is not violated
2411          */
2412         private void checkHMACChain(SlotIndexer indexer, Slot[] newSlots) {
2413                 for (int i = 0; i < newSlots.length; i++) {
2414                         Slot currSlot = newSlots[i];
2415                         Slot prevSlot = indexer.getSlot(currSlot.getSequenceNumber() - 1);
2416                         if (prevSlot != null &&
2417                                 !Arrays.equals(prevSlot.getHMAC(), currSlot.getPrevHMAC()))
2418                                 throw new Error("Server Error: Invalid HMAC Chain" + currSlot + " " + prevSlot);
2419                 }
2420         }
2421 }