| 1 | <?php |
| 2 | /* |
| 3 | * $Id: Pessimistic.php 4104 2008-03-24 01:06:27Z jwage $ |
| 4 | * |
| 5 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 6 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 7 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 8 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 9 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 10 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 11 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 12 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 13 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 14 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 15 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 16 | * |
| 17 | * This software consists of voluntary contributions made by many individuals |
| 18 | * and is licensed under the LGPL. For more information, see |
| 19 | * <http://www.phpdoctrine.org>. |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * Offline locking of records comes in handy where you need to make sure that |
| 24 | * a time-consuming task on a record or many records, which is spread over several |
| 25 | * page requests can't be interfered by other users. |
| 26 | * |
| 27 | * @package Doctrine |
| 28 | * @subpackage Locking |
| 29 | * @link www.phpdoctrine.org |
| 30 | * @author Roman Borschel <roman@code-factory.org> |
| 31 | * @author Pierre Minnieur <pm@pierre-minnieur.de> |
| 32 | * @author Konsta Vesterinen <kvesteri@cc.hut.fi> |
| 33 | * @license http://www.opensource.org/licenses/lgpl-license.php LGPL |
| 34 | * @since 1.0 |
| 35 | * @version $Revision: 4104 $ |
| 36 | */ |
| 37 | class Doctrine_Locking_Manager_Pessimistic |
| 38 | { |
| 39 | /** |
| 40 | * The conn that is used by the locking manager |
| 41 | * |
| 42 | * @var Doctrine_Connection object |
| 43 | */ |
| 44 | private $conn; |
| 45 | |
| 46 | /** |
| 47 | * The database table name for the lock tracking |
| 48 | */ |
| 49 | private $_lockTable = 'doctrine_lock_tracking'; |
| 50 | |
| 51 | /** |
| 52 | * Constructs a new locking manager object |
| 53 | * |
| 54 | * When the CREATE_TABLES attribute of the connection on which the manager |
| 55 | * is supposed to work on is set to true, the locking table is created. |
| 56 | * |
| 57 | * @param Doctrine_Connection $conn The database connection to use |
| 58 | */ |
| 59 | public function __construct(Doctrine_Connection $conn) |
| 60 | { |
| 61 | $this->conn = $conn; |
| 62 | |
| 63 | if ($this->conn->getAttribute(Doctrine::ATTR_EXPORT) & Doctrine::EXPORT_TABLES) { |
| 64 | $columns = array(); |
| 65 | $columns['object_type'] = array('type' => 'string', |
| 66 | 'length' => 50, |
| 67 | 'notnull' => true, |
| 68 | 'primary' => true); |
| 69 | |
| 70 | $columns['object_key'] = array('type' => 'string', |
| 71 | 'length' => 250, |
| 72 | 'notnull' => true, |
| 73 | 'primary' => true); |
| 74 | |
| 75 | $columns['user_ident'] = array('type' => 'string', |
| 76 | 'length' => 50, |
| 77 | 'notnull' => true); |
| 78 | |
| 79 | $columns['timestamp_obtained'] = array('type' => 'integer', |
| 80 | 'length' => 10, |
| 81 | 'notnull' => true); |
| 82 | |
| 83 | $options = array('primary' => array('object_type', 'object_key')); |
| 84 | try { |
| 85 | $this->conn->export->createTable($this->_lockTable, $columns, $options); |
| 86 | } catch(Exception $e) { |
| 87 | |
| 88 | } |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Obtains a lock on a {@link Doctrine_Record} |
| 94 | * |
| 95 | * @param Doctrine_Record $record The record that has to be locked |
| 96 | * @param mixed $userIdent A unique identifier of the locking user |
| 97 | * @return boolean TRUE if the locking was successful, FALSE if another user |
| 98 | * holds a lock on this record |
| 99 | * @throws Doctrine_Locking_Exception If the locking failed due to database errors |
| 100 | */ |
| 101 | public function getLock(Doctrine_Record $record, $userIdent) |
| 102 | { |
| 103 | $objectType = $record->getTable()->getComponentName(); |
| 104 | $key = $record->getTable()->getIdentifier(); |
| 105 | |
| 106 | $gotLock = false; |
| 107 | $time = time(); |
| 108 | |
| 109 | if (is_array($key)) { |
| 110 | // Composite key |
| 111 | $key = implode('|', $key); |
| 112 | } |
| 113 | |
| 114 | try { |
| 115 | $dbh = $this->conn->getDbh(); |
| 116 | $this->conn->beginTransaction(); |
| 117 | |
| 118 | $stmt = $dbh->prepare('INSERT INTO ' . $this->_lockTable |
| 119 | . ' (object_type, object_key, user_ident, timestamp_obtained)' |
| 120 | . ' VALUES (:object_type, :object_key, :user_ident, :ts_obtained)'); |
| 121 | |
| 122 | $stmt->bindParam(':object_type', $objectType); |
| 123 | $stmt->bindParam(':object_key', $key); |
| 124 | $stmt->bindParam(':user_ident', $userIdent); |
| 125 | $stmt->bindParam(':ts_obtained', $time); |
| 126 | |
| 127 | try { |
| 128 | $stmt->execute(); |
| 129 | $gotLock = true; |
| 130 | |
| 131 | // we catch an Exception here instead of PDOException since we might also be catching Doctrine_Exception |
| 132 | } catch(Exception $pkviolation) { |
| 133 | // PK violation occured => existing lock! |
| 134 | } |
| 135 | |
| 136 | if ( ! $gotLock) { |
| 137 | $lockingUserIdent = $this->_getLockingUserIdent($objectType, $key); |
| 138 | if ($lockingUserIdent !== null && $lockingUserIdent == $userIdent) { |
| 139 | $gotLock = true; // The requesting user already has a lock |
| 140 | // Update timestamp |
| 141 | $stmt = $dbh->prepare('UPDATE ' . $this->_lockTable |
| 142 | . ' SET timestamp_obtained = :ts' |
| 143 | . ' WHERE object_type = :object_type AND' |
| 144 | . ' object_key = :object_key AND' |
| 145 | . ' user_ident = :user_ident'); |
| 146 | $stmt->bindParam(':ts', $time); |
| 147 | $stmt->bindParam(':object_type', $objectType); |
| 148 | $stmt->bindParam(':object_key', $key); |
| 149 | $stmt->bindParam(':user_ident', $lockingUserIdent); |
| 150 | $stmt->execute(); |
| 151 | } |
| 152 | } |
| 153 | $this->conn->commit(); |
| 154 | } catch (Exception $pdoe) { |
| 155 | $this->conn->rollback(); |
| 156 | throw new Doctrine_Locking_Exception($pdoe->getMessage()); |
| 157 | } |
| 158 | |
| 159 | return $gotLock; |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * Releases a lock on a {@link Doctrine_Record} |
| 164 | * |
| 165 | * @param Doctrine_Record $record The record for which the lock has to be released |
| 166 | * @param mixed $userIdent The unique identifier of the locking user |
| 167 | * @return boolean TRUE if a lock was released, FALSE if no lock was released |
| 168 | * @throws Doctrine_Locking_Exception If the release procedure failed due to database errors |
| 169 | */ |
| 170 | public function releaseLock(Doctrine_Record $record, $userIdent) |
| 171 | { |
| 172 | $objectType = $record->getTable()->getComponentName(); |
| 173 | $key = $record->getTable()->getIdentifier(); |
| 174 | |
| 175 | if (is_array($key)) { |
| 176 | // Composite key |
| 177 | $key = implode('|', $key); |
| 178 | } |
| 179 | |
| 180 | try { |
| 181 | $dbh = $this->conn->getDbh(); |
| 182 | $stmt = $dbh->prepare("DELETE FROM $this->_lockTable WHERE |
| 183 | object_type = :object_type AND |
| 184 | object_key = :object_key AND |
| 185 | user_ident = :user_ident"); |
| 186 | $stmt->bindParam(':object_type', $objectType); |
| 187 | $stmt->bindParam(':object_key', $key); |
| 188 | $stmt->bindParam(':user_ident', $userIdent); |
| 189 | $stmt->execute(); |
| 190 | |
| 191 | $count = $stmt->rowCount(); |
| 192 | |
| 193 | return ($count > 0); |
| 194 | } catch (PDOException $pdoe) { |
| 195 | throw new Doctrine_Locking_Exception($pdoe->getMessage()); |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | /** |
| 200 | * Gets the unique user identifier of a lock |
| 201 | * |
| 202 | * @param string $objectType The type of the object (component name) |
| 203 | * @param mixed $key The unique key of the object |
| 204 | * @return mixed The unique user identifier for the specified lock |
| 205 | * @throws Doctrine_Locking_Exception If the query failed due to database errors |
| 206 | */ |
| 207 | private function _getLockingUserIdent($objectType, $key) |
| 208 | { |
| 209 | if (is_array($key)) { |
| 210 | // Composite key |
| 211 | $key = implode('|', $key); |
| 212 | } |
| 213 | |
| 214 | try { |
| 215 | $dbh = $this->conn->getDbh(); |
| 216 | $stmt = $dbh->prepare('SELECT user_ident FROM ' . $this->_lockTable |
| 217 | . ' WHERE object_type = :object_type AND object_key = :object_key'); |
| 218 | $stmt->bindParam(':object_type', $objectType); |
| 219 | $stmt->bindParam(':object_key', $key); |
| 220 | $success = $stmt->execute(); |
| 221 | |
| 222 | if ( ! $success) { |
| 223 | throw new Doctrine_Locking_Exception("Failed to determine locking user"); |
| 224 | } |
| 225 | |
| 226 | $userIdent = $stmt->fetchColumn(); |
| 227 | } catch (PDOException $pdoe) { |
| 228 | throw new Doctrine_Locking_Exception($pdoe->getMessage()); |
| 229 | } |
| 230 | |
| 231 | return $userIdent; |
| 232 | } |
| 233 | |
| 234 | /** |
| 235 | * Gets the identifier that identifies the owner of the lock on the given |
| 236 | * record. |
| 237 | * |
| 238 | * @param Doctrine_Record $lockedRecord The record. |
| 239 | * @return mixed The unique user identifier that identifies the owner of the lock. |
| 240 | */ |
| 241 | public function getLockOwner($lockedRecord) |
| 242 | { |
| 243 | $objectType = $lockedRecord->getTable()->getComponentName(); |
| 244 | $key = $lockedRecord->getTable()->getIdentifier(); |
| 245 | return $this->_getLockingUserIdent($objectType, $key); |
| 246 | } |
| 247 | |
| 248 | /** |
| 249 | * Releases locks older than a defined amount of seconds |
| 250 | * |
| 251 | * When called without parameters all locks older than 15 minutes are released. |
| 252 | * |
| 253 | * @param integer $age The maximum valid age of locks in seconds |
| 254 | * @param string $objectType The type of the object (component name) |
| 255 | * @param mixed $userIdent The unique identifier of the locking user |
| 256 | * @return integer The number of locks that have been released |
| 257 | * @throws Doctrine_Locking_Exception If the release process failed due to database errors |
| 258 | */ |
| 259 | public function releaseAgedLocks($age = 900, $objectType = null, $userIdent = null) |
| 260 | { |
| 261 | $age = time() - $age; |
| 262 | |
| 263 | try { |
| 264 | $dbh = $this->conn->getDbh(); |
| 265 | $stmt = $dbh->prepare('DELETE FROM ' . $this->_lockTable . ' WHERE timestamp_obtained < :age'); |
| 266 | $stmt->bindParam(':age', $age); |
| 267 | $query = 'DELETE FROM ' . $this->_lockTable . ' WHERE timestamp_obtained < :age'; |
| 268 | if ($objectType) { |
| 269 | $query .= ' AND object_type = :object_type'; |
| 270 | } |
| 271 | if ($userIdent) { |
| 272 | $query .= ' AND user_ident = :user_ident'; |
| 273 | } |
| 274 | $stmt = $dbh->prepare($query); |
| 275 | $stmt->bindParam(':age', $age); |
| 276 | if ($objectType) { |
| 277 | $stmt->bindParam(':object_type', $objectType); |
| 278 | } |
| 279 | if ($userIdent) { |
| 280 | $stmt->bindParam(':user_ident', $userIdent); |
| 281 | } |
| 282 | $stmt->execute(); |
| 283 | |
| 284 | $count = $stmt->rowCount(); |
| 285 | |
| 286 | return $count; |
| 287 | } catch (PDOException $pdoe) { |
| 288 | throw new Doctrine_Locking_Exception($pdoe->getMessage()); |
| 289 | } |
| 290 | } |
| 291 | } |