gerrit.onap Code Review - appc.git/blob

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  * ONAP : APPC
   4  * ================================================================================
   5  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Copyright (C) 2017 Amdocs
   8  * =============================================================================
   9  * Licensed under the Apache License, Version 2.0 (the "License");
  10  * you may not use this file except in compliance with the License.
  11  * You may obtain a copy of the License at
  12  *
  13  *      http://www.apache.org/licenses/LICENSE-2.0
  14  *
  15  * Unless required by applicable law or agreed to in writing, software
  16  * distributed under the License is distributed on an "AS IS" BASIS,
  17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18  * See the License for the specific language governing permissions and
  19  * limitations under the License.
  20  *
  21  * ECOMP is a trademark and service mark of AT&T Intellectual Property.
  22  * ============LICENSE_END=========================================================
  23  */
  24
  25 package org.openecomp.appc.lockmanager.impl.sql.optimistic;
  26
  27 import java.sql.Connection;
  28 import java.sql.PreparedStatement;
  29 import java.sql.ResultSet;
  30 import java.sql.SQLException;
  31
  32 import org.openecomp.appc.lockmanager.api.LockException;
  33 import org.openecomp.appc.lockmanager.api.LockRuntimeException;
  34 import org.openecomp.appc.lockmanager.impl.sql.JdbcLockManager;
  35 import org.openecomp.appc.lockmanager.impl.sql.Messages;
  36
  37 abstract class SqlLockManager extends JdbcLockManager {
  38
  39         private static final String SQL_LOAD_LOCK_RECORD = "SELECT * FROM %s WHERE RESOURCE_ID=?";
  40         private static final String SQL_INSERT_LOCK_RECORD = "INSERT INTO %s (RESOURCE_ID, OWNER_ID, UPDATED, TIMEOUT, VER) VALUES (?, ?, ?, ?, ?)";
  41         private static final String SQL_UPDATE_LOCK_RECORD = "UPDATE %s SET OWNER_ID=?, UPDATED=?, TIMEOUT=?, VER=? WHERE RESOURCE_ID=? AND VER=?";
  42 //      private static final String SQL_DELETE_LOCK_RECORD = "DELETE FROM %s WHERE RESOURCE_ID=? AND VER=?";
  43         private static final String SQL_CURRENT_TIMESTAMP = "SELECT CURRENT_TIMESTAMP()";
  44
  45         private String sqlLoadLockRecord;
  46         private String sqlInsertLockRecord;
  47         private String sqlUpdateLockRecord;
  48 //      private String sqlDeleteLockRecord;
  49
  50         @Override
  51         public boolean acquireLock(String resource, String owner) throws LockException {
  52                 return acquireLock(resource, owner, 0);
  53         }
  54
  55         @Override
  56         public boolean acquireLock(String resource, String owner, long timeout) throws LockException {
  57                 if(owner == null) {
  58                         throw new LockRuntimeException(Messages.ERR_NULL_LOCK_OWNER.format(resource));
  59                 }
  60                 boolean res = false;
  61                 Connection connection = openDbConnection();
  62                 try {
  63                         res = lockResource(connection, resource, owner, timeout);
  64                 } finally {
  65                         closeDbConnection(connection);
  66                 }
  67                 return res;
  68         }
  69
  70         @Override
  71         public void releaseLock(String resource, String owner) throws LockException {
  72                 Connection connection = openDbConnection();
  73                 try {
  74                         unlockResource(connection, resource, owner);
  75                 } finally {
  76                         closeDbConnection(connection);
  77                 }
  78         }
  79
  80         @Override
  81         public boolean isLocked(String resource) {
  82         Connection connection=openDbConnection();
  83                 try {
  84                         LockRecord lockRecord=loadLockRecord(connection,resource);
  85                         if(lockRecord==null){
  86                                 return false;
  87                         }else{
  88                                 if(lockRecord.getOwner()==null){
  89                                         return false;
  90                                 }else if(isLockExpired(lockRecord, connection)){
  91                                         return false;
  92                                 }else{
  93                     return true;
  94                 }
  95                         }
  96                 } catch (SQLException e) {
  97                         throw new LockRuntimeException(Messages.EXP_CHECK_LOCK.format(resource));
  98                 }finally {
  99             closeDbConnection(connection);
 100         }
 101     }
 102
 103         private boolean lockResource(Connection connection, String resource, String owner, long timeout) throws LockException {
 104                 try {
 105                         boolean res = false;
 106                         LockRecord lockRecord = loadLockRecord(connection, resource);
 107                         if(lockRecord != null) {
 108                                 // lock record already exists
 109                                 String currentOwner = lockRecord.getOwner();
 110                                 if(currentOwner != null) {
 111                                         if(isLockExpired(lockRecord, connection)) {
 112                                                 currentOwner = null;
 113                                         } else if(!owner.equals(currentOwner)) {
 114                                                 throw new LockException(Messages.ERR_LOCK_LOCKED_BY_OTHER.format(resource, owner, currentOwner));
 115                                         }
 116                                 }
 117                                 // set new owner on the resource lock record
 118                                 if(!updateLockRecord(connection, resource, owner, timeout, lockRecord.getVer())) {
 119                                         // try again - maybe same owner updated the record
 120                                         lockResource(connection, resource, owner, timeout);
 121                                 }
 122                                 if(currentOwner == null) {
 123                                         // no one locked the resource before
 124                                         res = true;
 125                                 }
 126                         } else {
 127                                 // resource record does not exist in lock table => create new record
 128                                 try {
 129                                         addLockRecord(connection, resource, owner, timeout);
 130                                         res = true;
 131                                 } catch(SQLException e) {
 132                                         if(isDuplicatePkError(e)) {
 133                                                 // try again - maybe same owner inserted the record
 134                                                 lockResource(connection, resource, owner, timeout);
 135                                         } else {
 136                                                 throw e;
 137                                         }
 138                                 }
 139                         }
 140                         return res;
 141                 } catch(SQLException e) {
 142                         throw new LockRuntimeException(Messages.EXP_LOCK.format(resource), e);
 143                 }
 144         }
 145
 146         protected boolean isDuplicatePkError(SQLException e) {
 147                 return e.getSQLState().startsWith("23");
 148         }
 149
 150         private void unlockResource(Connection connection, String resource, String owner) throws LockException {
 151                 try {
 152                         LockRecord lockRecord = loadLockRecord(connection, resource);
 153                         if(lockRecord != null) {
 154                                 // check if expired
 155                                 if(isLockExpired(lockRecord, connection)) {
 156                                         // lock is expired => no lock
 157                                         lockRecord = null;
 158                                 }
 159                         }
 160                         if((lockRecord == null) || (lockRecord.getOwner() == null)) {
 161                                 // resource is not locked
 162                                 throw new LockException(Messages.ERR_UNLOCK_NOT_LOCKED.format(resource));
 163                         }
 164                         String currentOwner = lockRecord.getOwner();
 165                         if(!owner.equals(currentOwner)) {
 166                                 throw new LockException(Messages.ERR_UNLOCK_LOCKED_BY_OTHER.format(resource, owner, currentOwner));
 167             }
 168             if (!updateLockRecord(connection, resource, null, 0, lockRecord.getVer())) {
 169                                 unlockResource(connection, resource, owner);
 170                         }
 171                         // TODO delete record from table on lock release?
 172 //                      deleteLockRecord(connection, resource, lockRecord.getVer());
 173                 } catch(SQLException e) {
 174                         throw new LockRuntimeException(Messages.EXP_UNLOCK.format(resource), e);
 175                 }
 176         }
 177
 178         protected LockRecord loadLockRecord(Connection connection, String resource) throws SQLException {
 179                 LockRecord res = null;
 180                 if(sqlLoadLockRecord == null) {
 181                         sqlLoadLockRecord = String.format(SQL_LOAD_LOCK_RECORD, tableName);
 182                 }
 183                 try(PreparedStatement statement = connection.prepareStatement(sqlLoadLockRecord)) {
 184                         statement.setString(1, resource);
 185                         try(ResultSet resultSet = statement.executeQuery()) {
 186                                 if(resultSet.next()) {
 187                                         res = new LockRecord(resource);
 188                                         res.setOwner(resultSet.getString(2));
 189                                         res.setUpdated(resultSet.getLong(3));
 190                                         res.setTimeout(resultSet.getLong(4));
 191                                         res.setVer(resultSet.getLong(5));
 192                                 }
 193                         }
 194                 }
 195                 return res;
 196         }
 197
 198         protected void addLockRecord(Connection connection, String resource, String owner, long timeout) throws SQLException {
 199                 if(sqlInsertLockRecord == null) {
 200                         sqlInsertLockRecord = String.format(SQL_INSERT_LOCK_RECORD, tableName);
 201                 }
 202                 try(PreparedStatement statement = connection.prepareStatement(sqlInsertLockRecord)) {
 203                         statement.setString(1, resource);
 204                         statement.setString(2, owner);
 205             statement.setLong(3, getCurrentTime(connection));
 206                         statement.setLong(4, timeout);
 207                         statement.setLong(5, 1);
 208                         statement.executeUpdate();
 209                 }
 210         }
 211
 212         protected boolean updateLockRecord(Connection connection, String resource, String owner, long timeout, long ver) throws SQLException {
 213                 if(sqlUpdateLockRecord == null) {
 214                         sqlUpdateLockRecord = String.format(SQL_UPDATE_LOCK_RECORD, tableName);
 215                 }
 216                 try(PreparedStatement statement = connection.prepareStatement(sqlUpdateLockRecord)) {
 217                         long newVer = (ver >= Long.MAX_VALUE) ? 1 : (ver + 1);
 218                         statement.setString(1, owner);
 219             statement.setLong(2, getCurrentTime(connection));
 220                         statement.setLong(3, timeout);
 221                         statement.setLong(4, newVer);
 222                         statement.setString(5, resource);
 223                         statement.setLong(6, ver);
 224                         return (statement.executeUpdate() != 0);
 225                 }
 226         }
 227
 228 //      protected void deleteLockRecord(Connection connection, String resource, long ver) throws SQLException {
 229 //              if(sqlDeleteLockRecord == null) {
 230 //                      sqlDeleteLockRecord = String.format(SQL_DELETE_LOCK_RECORD, tableName);
 231 //              }
 232 //              try(PreparedStatement statement = connection.prepareStatement(sqlDeleteLockRecord)) {
 233 //                      statement.setString(1, resource);
 234 //                      statement.setLong(2, ver);
 235 //                      statement.executeUpdate();
 236 //              }
 237 //      }
 238
 239         private boolean isLockExpired(LockRecord lockRecord, Connection connection) throws SQLException {
 240                 long timeout = lockRecord.getTimeout();
 241                 if(timeout == 0) {
 242                         return false;
 243                 }
 244                 long updated = lockRecord.getUpdated();
 245         long now = getCurrentTime(connection);
 246                 long expiration = updated + timeout;
 247                 return (now > expiration);
 248         }
 249
 250         private long getCurrentTime(Connection connection) throws SQLException {
 251                 long res = -1;
 252                 if(connection != null) {
 253                         try(PreparedStatement statement = connection.prepareStatement(SQL_CURRENT_TIMESTAMP)) {
 254                                 try(ResultSet resultSet = statement.executeQuery()) {
 255                                         if(resultSet.next()) {
 256                                                 res = resultSet.getTimestamp(1).getTime();
 257                                         }
 258                                 }
 259                         }
 260                 }
 261                 if(res == -1) {
 262                         res = System.currentTimeMillis();
 263                 }
 264                 return res;
 265         }
 266 }