gerrit.onap Code Review - appc.git/blob

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