src/main/java/org/onap/music/lockingservice/MusicLockingService.java

   1 /*
   2  * ============LICENSE_START========================================== org.onap.music
   3  * =================================================================== Copyright (c) 2017 AT&T
   4  * Intellectual Property ===================================================================
   5  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
   6  * in compliance with the License. You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software distributed under the License
  11  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
  12  * or implied. See the License for the specific language governing permissions and limitations under
  13  * the License.
  14  *
  15  * ============LICENSE_END=============================================
  16  * ====================================================================
  17  */
  18 package org.onap.music.lockingservice;
  19
  20
  21 import java.io.IOException;
  22 import java.io.PrintWriter;
  23 import java.io.StringWriter;
  24 import java.util.StringTokenizer;
  25 import java.util.concurrent.CountDownLatch;
  26
  27 import org.apache.zookeeper.KeeperException;
  28 import org.apache.zookeeper.WatchedEvent;
  29 import org.apache.zookeeper.Watcher;
  30 import org.apache.zookeeper.Watcher.Event.KeeperState;
  31 import org.apache.zookeeper.ZooKeeper;
  32 import org.onap.music.eelf.logging.EELFLoggerDelegate;
  33 import org.onap.music.eelf.logging.format.AppMessages;
  34 import org.onap.music.eelf.logging.format.ErrorSeverity;
  35 import org.onap.music.eelf.logging.format.ErrorTypes;
  36 import org.onap.music.exceptions.MusicLockingException;
  37 import org.onap.music.exceptions.MusicServiceException;
  38 import org.onap.music.main.MusicUtil;
  39
  40
  41 public class MusicLockingService implements Watcher {
  42
  43
  44     private static final int SESSION_TIMEOUT = 180000;
  45     ZkStatelessLockService zkLockHandle = null;
  46     private CountDownLatch connectedSignal = new CountDownLatch(1);
  47     private static EELFLoggerDelegate logger =
  48                     EELFLoggerDelegate.getLogger(MusicLockingService.class);
  49
  50     public MusicLockingService() throws MusicServiceException {
  51         try {
  52             ZooKeeper zk = new ZooKeeper(MusicUtil.getMyZkHost(), SESSION_TIMEOUT, this);
  53             connectedSignal.await();
  54             zkLockHandle = new ZkStatelessLockService(zk);
  55         } catch (IOException e) {
  56             logger.error(EELFLoggerDelegate.errorLogger, e.getMessage(),AppMessages.IOERROR, ErrorSeverity.ERROR, ErrorTypes.CONNECTIONERROR);
  57             throw new MusicServiceException("IO Error has occured" + e.getMessage());
  58         } catch (InterruptedException e) {
  59                 logger.error(EELFLoggerDelegate.errorLogger, e.getMessage(),AppMessages.EXECUTIONINTERRUPTED, ErrorSeverity.ERROR, ErrorTypes.LOCKINGERROR);
  60             throw new MusicServiceException("Exception Occured " + e.getMessage());
  61         }
  62     }
  63
  64     public ZkStatelessLockService getzkLockHandle() {
  65         return zkLockHandle;
  66     }
  67
  68     public MusicLockingService(String lockServer) {
  69         try {
  70             ZooKeeper zk = new ZooKeeper(lockServer, SESSION_TIMEOUT, this);
  71             connectedSignal.await();
  72             zkLockHandle = new ZkStatelessLockService(zk);
  73         } catch (IOException e) {
  74                 logger.error(EELFLoggerDelegate.errorLogger, e.getMessage(),AppMessages.IOERROR, ErrorSeverity.ERROR, ErrorTypes.CONNECTIONERROR);
  75         }catch( InterruptedException e) {
  76                 logger.error(EELFLoggerDelegate.errorLogger, e.getMessage(),AppMessages.EXECUTIONINTERRUPTED, ErrorSeverity.ERROR, ErrorTypes.LOCKINGERROR);
  77                 }catch(Exception e) {
  78                         logger.error(EELFLoggerDelegate.errorLogger, e.getMessage(),AppMessages.UNKNOWNERROR, ErrorSeverity.ERROR, ErrorTypes.LOCKINGERROR);
  79                 }
  80     }
  81
  82     public void createLockaIfItDoesNotExist(String lockName) {
  83         if (!zkLockHandle.checkIfLockExists(lockName)) {
  84             String lockHolder = null;
  85             MusicLockState ml = new MusicLockState(MusicLockState.LockStatus.UNLOCKED, lockHolder);
  86             byte[] data = ml.serialize();
  87             zkLockHandle.createLock(lockName, data);
  88         }
  89     }
  90
  91     public void setLockState(String lockName, MusicLockState mls) {
  92         byte[] data = mls.serialize();
  93         zkLockHandle.setNodeData(lockName, data);
  94     }
  95
  96     public MusicLockState getLockState(String lockName) throws MusicLockingException {
  97
  98         byte[] data = null;
  99         try{
 100                 data = zkLockHandle.getNodeData(lockName);
 101         }catch (Exception ex){
 102                 StringWriter sw = new StringWriter();
 103                         ex.printStackTrace();
 104                         ex.printStackTrace(new PrintWriter(sw));
 105                         String exceptionAsString = sw.toString();
 106                         logger.error(EELFLoggerDelegate.errorLogger,exceptionAsString);
 107                 throw new  MusicLockingException(exceptionAsString);
 108         }
 109         if(data !=null)
 110         return MusicLockState.deSerialize(data);
 111         else {
 112                 logger.error(EELFLoggerDelegate.errorLogger,"",AppMessages.INVALIDLOCK, ErrorSeverity.ERROR, ErrorTypes.LOCKINGERROR);
 113                 throw new  MusicLockingException("Invalid lock or acquire failed");
 114         }
 115     }
 116
 117     public String createLockId(String lockName) {
 118         String lockIdWithSlash = zkLockHandle.createLockId(lockName);
 119         return lockIdWithSlash.replace('/', '$');
 120     }
 121
 122     public boolean isMyTurn(String lockIdWithDollar) {
 123         String lockId = lockIdWithDollar.replace('$', '/');
 124         StringTokenizer st = new StringTokenizer(lockId);
 125         String lockName = "/" + st.nextToken("/");
 126         try {
 127             return zkLockHandle.lock(lockName, lockId);
 128         } catch (KeeperException e) {
 129                 logger.error(EELFLoggerDelegate.errorLogger, e.getMessage(),AppMessages.LOCKINGERROR, ErrorSeverity.ERROR, ErrorTypes.LOCKINGERROR);
 130         }catch( InterruptedException e) {
 131                 logger.error(EELFLoggerDelegate.errorLogger, e.getMessage(),AppMessages.EXECUTIONINTERRUPTED, ErrorSeverity.ERROR, ErrorTypes.LOCKINGERROR);
 132                 }catch(Exception e) {
 133                         logger.error(EELFLoggerDelegate.errorLogger, e.getMessage(),AppMessages.UNKNOWNERROR, ErrorSeverity.ERROR, ErrorTypes.LOCKINGERROR);
 134                 }
 135         return false;
 136     }
 137
 138     public void unlockAndDeleteId(String lockIdWithDollar) throws KeeperException.NoNodeException {
 139         String lockId = lockIdWithDollar.replace('$', '/');
 140         zkLockHandle.unlock(lockId);
 141     }
 142
 143     public void deleteLock(String lockName) throws MusicLockingException {
 144         if(lockIdExists(lockName))
 145                 zkLockHandle.deleteLock(lockName);
 146         else{
 147                 throw new MusicLockingException("Lock does not exist.Please check the lock: " + lockName + " and try again");
 148         }
 149     }
 150
 151     public String whoseTurnIsIt(String lockName) {
 152         String lockHolder = zkLockHandle.currentLockHolder(lockName);
 153         return lockHolder.replace('/', '$');
 154
 155     }
 156
 157     public void process(WatchedEvent event) { // Watcher interface
 158         if (event.getState() == KeeperState.SyncConnected) {
 159             connectedSignal.countDown();
 160         }
 161     }
 162
 163
 164     public void close() {
 165         zkLockHandle.close();
 166     }
 167
 168         public boolean lockIdExists(String lockIdWithDollar) {
 169                 String lockId = lockIdWithDollar.replace('$', '/');
 170                 return zkLockHandle.checkIfLockExists(lockId);
 171         }
 172
 173 }