appc-dispatcher/appc-dispatcher-common/lock-manager-lib/lock-manager-impl/src/main/java/org/openecomp/appc/lockmanager/impl/sql/optimistic/SqlLockManager.java

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