code: /**
  Copyright (c) 2007-2013 Alysson Bessani, Eduardo Alchieri, Paulo Sousa, and the authors indicated in the @author tags
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
  http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  */
  package bftsmart.clientsmanagement;
  
  import java.security.PublicKey;
  import java.security.Signature;
  import java.security.SignatureException;
  import java.util.Iterator;
  import java.util.concurrent.locks.ReentrantLock;
  
  import bftsmart.tom.core.messages.TOMMessage;
  import bftsmart.tom.util.Logger;
  import bftsmart.tom.util.TOMUtil;
  
  
  public class ClientData {
      private final static org.apache.log4j.Logger logger = org.apache.log4j.Logger.getLogger(ClientData.class);
  
      ReentrantLock clientLock = new ReentrantLock();
  
      private int clientId;
      //private PublicKey publicKey = null;
  
      private int session = -1;
  
      private int lastMessageReceived = -1;
      private long lastMessageReceivedTime = 0;
  
      private int lastMessageExecuted = -1;
  
      private RequestList pendingRequests = new RequestList();
      //anb: new code to deal with client requests that arrive after their execution
      private RequestList orderedRequests = new RequestList(5);
  
      private Signature signatureVerificator = null;
      
      /**
       * Class constructor. Just store the clientId and creates a signature
       * verificator for a given client public key.
       *
       * @param clientId client unique id
       * @param publicKey client public key
       */
      public ClientData(int clientId, PublicKey publicKey) {
          this.clientId = clientId;
          if(publicKey != null) {
              try {
                  signatureVerificator = Signature.getInstance("SHA1withRSA");
                  signatureVerificator.initVerify(publicKey);
                  logger.info("Signature verifier initialized for client "+clientId);
              } catch (Exception ex) {
                  logger.error("", ex);
              }
          }
      }
  
      public int getClientId() {
          return clientId;
      }
  
      public int getSession() {
          return session;
      }
  
      public void setSession(int session) {
          this.session = session;
      }
  
      public RequestList getPendingRequests() {
          return pendingRequests;
      }
  
      public RequestList getOrderedRequests() {
          return orderedRequests;
      }
  
      public void setLastMessageExecuted(int lastMessageExecuted) {
          this.lastMessageExecuted = lastMessageExecuted;
      }
  
      public int getLastMessageExecuted() {
          return lastMessageExecuted;
      }
  
      public void setLastMessageReceived(int lastMessageReceived) {
          this.lastMessageReceived = lastMessageReceived;
      }
  
      public int getLastMessageReceived() {
          return lastMessageReceived;
      }
  
      public void setLastMessageReceivedTime(long lastMessageReceivedTime) {
          this.lastMessageReceivedTime = lastMessageReceivedTime;
      }
  
      public long getLastMessageReceivedTime() {
          return lastMessageReceivedTime;
      }
  
      public boolean verifySignature(byte[] message, byte[] signature) {
          if(signatureVerificator != null) {
              try {
                  return TOMUtil.verifySignature(signatureVerificator, message, signature);
              } catch (SignatureException ex) {
                  logger.warn("Error in processing client "+clientId+" signature: "+ex.getMessage());
              }
          }
          return false;
      }
  
      public boolean removeOrderedRequest(TOMMessage request) {
          if(pendingRequests.remove(request)) {
              //anb: new code to deal with client requests that arrive after their execution
              orderedRequests.addLast(request);
              return true;
          }
          return false;
      }
  
      public boolean removeRequest(TOMMessage request) {
  	lastMessageExecuted = request.getSequence();
  	boolean result = pendingRequests.remove(request);
          //anb: new code to deal with client requests that arrive after their execution
          orderedRequests.addLast(request);
  
  	for(Iterator<TOMMessage> it = pendingRequests.iterator();it.hasNext();){
  		TOMMessage msg = it.next();
  		if(msg.getSequence()<request.getSequence()){
  			it.remove();
  		}
  	}
  
      	return result;
      }
  
      public TOMMessage getReply(int reqSequence) {
          TOMMessage request = orderedRequests.getBySequence(reqSequence);
          if(request != null) {
              return request.reply;
          } else {
              return null;
          }
      }
  
  }
  