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| 1 | +<?php |
| 2 | + |
| 3 | +/* |
| 4 | + * This file is part of the Symfony package. |
| 5 | + * |
| 6 | + * (c) Fabien Potencier <fabien@symfony.com> |
| 7 | + * |
| 8 | + * For the full copyright and license information, please view the LICENSE |
| 9 | + * file that was distributed with this source code. |
| 10 | + */ |
| 11 | + |
| 12 | +namespace Symfony\Component\HttpFoundation\Session\Storage\Handler; |
| 13 | + |
| 14 | +/** |
| 15 | + * Session handler using a PDO connection to read and write data. |
| 16 | + * |
| 17 | + * Session data is a binary string that can contain non-printable characters like the null byte. |
| 18 | + * For this reason this handler base64 encodes the data to be able to save it in a character column. |
| 19 | + * |
| 20 | + * This version of the PdoSessionHandler does NOT implement locking. So concurrent requests to the |
| 21 | + * same session can result in data loss due to race conditions. |
| 22 | + * |
| 23 | + * @author Fabien Potencier <fabien@symfony.com> |
| 24 | + * @author Michael Williams <michael.williams@funsational.com> |
| 25 | + * @author Tobias Schultze <http://tobion.de> |
| 26 | + * |
| 27 | + * @deprecated Deprecated since version 2.6, to be removed in 3.0. Use |
| 28 | + * {@link PdoSessionHandler} instead. |
| 29 | + */ |
| 30 | +class LegacyPdoSessionHandler implements \SessionHandlerInterface |
| 31 | +{ |
| 32 | + /** |
| 33 | + * @var \PDO PDO instance |
| 34 | + */ |
| 35 | + private $pdo; |
| 36 | + |
| 37 | + /** |
| 38 | + * @var string Table name |
| 39 | + */ |
| 40 | + private $table; |
| 41 | + |
| 42 | + /** |
| 43 | + * @var string Column for session id |
| 44 | + */ |
| 45 | + private $idCol; |
| 46 | + |
| 47 | + /** |
| 48 | + * @var string Column for session data |
| 49 | + */ |
| 50 | + private $dataCol; |
| 51 | + |
| 52 | + /** |
| 53 | + * @var string Column for timestamp |
| 54 | + */ |
| 55 | + private $timeCol; |
| 56 | + |
| 57 | + /** |
| 58 | + * Constructor. |
| 59 | + * |
| 60 | + * List of available options: |
| 61 | + * * db_table: The name of the table [required] |
| 62 | + * * db_id_col: The column where to store the session id [default: sess_id] |
| 63 | + * * db_data_col: The column where to store the session data [default: sess_data] |
| 64 | + * * db_time_col: The column where to store the timestamp [default: sess_time] |
| 65 | + * |
| 66 | + * @param \PDO $pdo A \PDO instance |
| 67 | + * @param array $dbOptions An associative array of DB options |
| 68 | + * |
| 69 | + * @throws \InvalidArgumentException When "db_table" option is not provided |
| 70 | + */ |
| 71 | + public function __construct(\PDO $pdo, array $dbOptions = array()) |
| 72 | + { |
| 73 | + if (!array_key_exists('db_table', $dbOptions)) { |
| 74 | + throw new \InvalidArgumentException('You must provide the "db_table" option for a PdoSessionStorage.'); |
| 75 | + } |
| 76 | + if (\PDO::ERRMODE_EXCEPTION !== $pdo->getAttribute(\PDO::ATTR_ERRMODE)) { |
| 77 | + throw new \InvalidArgumentException(sprintf('"%s" requires PDO error mode attribute be set to throw Exceptions (i.e. $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION))', __CLASS__)); |
| 78 | + } |
| 79 | + $this->pdo = $pdo; |
| 80 | + $dbOptions = array_merge(array( |
| 81 | + 'db_id_col' => 'sess_id', |
| 82 | + 'db_data_col' => 'sess_data', |
| 83 | + 'db_time_col' => 'sess_time', |
| 84 | + ), $dbOptions); |
| 85 | + |
| 86 | + $this->table = $dbOptions['db_table']; |
| 87 | + $this->idCol = $dbOptions['db_id_col']; |
| 88 | + $this->dataCol = $dbOptions['db_data_col']; |
| 89 | + $this->timeCol = $dbOptions['db_time_col']; |
| 90 | + } |
| 91 | + |
| 92 | + /** |
| 93 | + * {@inheritdoc} |
| 94 | + */ |
| 95 | + public function open($savePath, $sessionName) |
| 96 | + { |
| 97 | + return true; |
| 98 | + } |
| 99 | + |
| 100 | + /** |
| 101 | + * {@inheritdoc} |
| 102 | + */ |
| 103 | + public function close() |
| 104 | + { |
| 105 | + return true; |
| 106 | + } |
| 107 | + |
| 108 | + /** |
| 109 | + * {@inheritdoc} |
| 110 | + */ |
| 111 | + public function destroy($sessionId) |
| 112 | + { |
| 113 | + // delete the record associated with this id |
| 114 | + $sql = "DELETE FROM $this->table WHERE $this->idCol = :id"; |
| 115 | + |
| 116 | + try { |
| 117 | + $stmt = $this->pdo->prepare($sql); |
| 118 | + $stmt->bindParam(':id', $sessionId, \PDO::PARAM_STR); |
| 119 | + $stmt->execute(); |
| 120 | + } catch (\PDOException $e) { |
| 121 | + throw new \RuntimeException(sprintf('PDOException was thrown when trying to delete a session: %s', $e->getMessage()), 0, $e); |
| 122 | + } |
| 123 | + |
| 124 | + return true; |
| 125 | + } |
| 126 | + |
| 127 | + /** |
| 128 | + * {@inheritdoc} |
| 129 | + */ |
| 130 | + public function gc($maxlifetime) |
| 131 | + { |
| 132 | + // delete the session records that have expired |
| 133 | + $sql = "DELETE FROM $this->table WHERE $this->timeCol < :time"; |
| 134 | + |
| 135 | + try { |
| 136 | + $stmt = $this->pdo->prepare($sql); |
| 137 | + $stmt->bindValue(':time', time() - $maxlifetime, \PDO::PARAM_INT); |
| 138 | + $stmt->execute(); |
| 139 | + } catch (\PDOException $e) { |
| 140 | + throw new \RuntimeException(sprintf('PDOException was thrown when trying to delete expired sessions: %s', $e->getMessage()), 0, $e); |
| 141 | + } |
| 142 | + |
| 143 | + return true; |
| 144 | + } |
| 145 | + |
| 146 | + /** |
| 147 | + * {@inheritdoc} |
| 148 | + */ |
| 149 | + public function read($sessionId) |
| 150 | + { |
| 151 | + $sql = "SELECT $this->dataCol FROM $this->table WHERE $this->idCol = :id"; |
| 152 | + |
| 153 | + try { |
| 154 | + $stmt = $this->pdo->prepare($sql); |
| 155 | + $stmt->bindParam(':id', $sessionId, \PDO::PARAM_STR); |
| 156 | + $stmt->execute(); |
| 157 | + |
| 158 | + // We use fetchAll instead of fetchColumn to make sure the DB cursor gets closed |
| 159 | + $sessionRows = $stmt->fetchAll(\PDO::FETCH_NUM); |
| 160 | + |
| 161 | + if ($sessionRows) { |
| 162 | + return base64_decode($sessionRows[0][0]); |
| 163 | + } |
| 164 | + |
| 165 | + return ''; |
| 166 | + } catch (\PDOException $e) { |
| 167 | + throw new \RuntimeException(sprintf('PDOException was thrown when trying to read the session data: %s', $e->getMessage()), 0, $e); |
| 168 | + } |
| 169 | + } |
| 170 | + |
| 171 | + /** |
| 172 | + * {@inheritdoc} |
| 173 | + */ |
| 174 | + public function write($sessionId, $data) |
| 175 | + { |
| 176 | + $encoded = base64_encode($data); |
| 177 | + |
| 178 | + try { |
| 179 | + // We use a single MERGE SQL query when supported by the database. |
| 180 | + $mergeSql = $this->getMergeSql(); |
| 181 | + |
| 182 | + if (null !== $mergeSql) { |
| 183 | + $mergeStmt = $this->pdo->prepare($mergeSql); |
| 184 | + $mergeStmt->bindParam(':id', $sessionId, \PDO::PARAM_STR); |
| 185 | + $mergeStmt->bindParam(':data', $encoded, \PDO::PARAM_STR); |
| 186 | + $mergeStmt->bindValue(':time', time(), \PDO::PARAM_INT); |
| 187 | + $mergeStmt->execute(); |
| 188 | + |
| 189 | + return true; |
| 190 | + } |
| 191 | + |
| 192 | + $updateStmt = $this->pdo->prepare( |
| 193 | + "UPDATE $this->table SET $this->dataCol = :data, $this->timeCol = :time WHERE $this->idCol = :id" |
| 194 | + ); |
| 195 | + $updateStmt->bindParam(':id', $sessionId, \PDO::PARAM_STR); |
| 196 | + $updateStmt->bindParam(':data', $encoded, \PDO::PARAM_STR); |
| 197 | + $updateStmt->bindValue(':time', time(), \PDO::PARAM_INT); |
| 198 | + $updateStmt->execute(); |
| 199 | + |
| 200 | + // When MERGE is not supported, like in Postgres, we have to use this approach that can result in |
| 201 | + // duplicate key errors when the same session is written simultaneously. We can just catch such an |
| 202 | + // error and re-execute the update. This is similar to a serializable transaction with retry logic |
| 203 | + // on serialization failures but without the overhead and without possible false positives due to |
| 204 | + // longer gap locking. |
| 205 | + if (!$updateStmt->rowCount()) { |
| 206 | + try { |
| 207 | + $insertStmt = $this->pdo->prepare( |
| 208 | + "INSERT INTO $this->table ($this->idCol, $this->dataCol, $this->timeCol) VALUES (:id, :data, :time)" |
| 209 | + ); |
| 210 | + $insertStmt->bindParam(':id', $sessionId, \PDO::PARAM_STR); |
| 211 | + $insertStmt->bindParam(':data', $encoded, \PDO::PARAM_STR); |
| 212 | + $insertStmt->bindValue(':time', time(), \PDO::PARAM_INT); |
| 213 | + $insertStmt->execute(); |
| 214 | + } catch (\PDOException $e) { |
| 215 | + // Handle integrity violation SQLSTATE 23000 (or a subclass like 23505 in Postgres) for duplicate keys |
| 216 | + if (0 === strpos($e->getCode(), '23')) { |
| 217 | + $updateStmt->execute(); |
| 218 | + } else { |
| 219 | + throw $e; |
| 220 | + } |
| 221 | + } |
| 222 | + } |
| 223 | + } catch (\PDOException $e) { |
| 224 | + throw new \RuntimeException(sprintf('PDOException was thrown when trying to write the session data: %s', $e->getMessage()), 0, $e); |
| 225 | + } |
| 226 | + |
| 227 | + return true; |
| 228 | + } |
| 229 | + |
| 230 | + /** |
| 231 | + * Returns a merge/upsert (i.e. insert or update) SQL query when supported by the database. |
| 232 | + * |
| 233 | + * @return string|null The SQL string or null when not supported |
| 234 | + */ |
| 235 | + private function getMergeSql() |
| 236 | + { |
| 237 | + $driver = $this->pdo->getAttribute(\PDO::ATTR_DRIVER_NAME); |
| 238 | + |
| 239 | + switch ($driver) { |
| 240 | + case 'mysql': |
| 241 | + return "INSERT INTO $this->table ($this->idCol, $this->dataCol, $this->timeCol) VALUES (:id, :data, :time) ". |
| 242 | + "ON DUPLICATE KEY UPDATE $this->dataCol = VALUES($this->dataCol), $this->timeCol = VALUES($this->timeCol)"; |
| 243 | + case 'oci': |
| 244 | + // DUAL is Oracle specific dummy table |
| 245 | + return "MERGE INTO $this->table USING DUAL ON ($this->idCol = :id) ". |
| 246 | + "WHEN NOT MATCHED THEN INSERT ($this->idCol, $this->dataCol, $this->timeCol) VALUES (:id, :data, :time) ". |
| 247 | + "WHEN MATCHED THEN UPDATE SET $this->dataCol = :data, $this->timeCol = :time"; |
| 248 | + case 'sqlsrv' === $driver && version_compare($this->pdo->getAttribute(\PDO::ATTR_SERVER_VERSION), '10', '>='): |
| 249 | + // MERGE is only available since SQL Server 2008 and must be terminated by semicolon |
| 250 | + // It also requires HOLDLOCK according to http://weblogs.sqlteam.com/dang/archive/2009/01/31/UPSERT-Race-Condition-With-MERGE.aspx |
| 251 | + return "MERGE INTO $this->table WITH (HOLDLOCK) USING (SELECT 1 AS dummy) AS src ON ($this->idCol = :id) ". |
| 252 | + "WHEN NOT MATCHED THEN INSERT ($this->idCol, $this->dataCol, $this->timeCol) VALUES (:id, :data, :time) ". |
| 253 | + "WHEN MATCHED THEN UPDATE SET $this->dataCol = :data, $this->timeCol = :time;"; |
| 254 | + case 'sqlite': |
| 255 | + return "INSERT OR REPLACE INTO $this->table ($this->idCol, $this->dataCol, $this->timeCol) VALUES (:id, :data, :time)"; |
| 256 | + } |
| 257 | + } |
| 258 | + |
| 259 | + /** |
| 260 | + * Return a PDO instance |
| 261 | + * |
| 262 | + * @return \PDO |
| 263 | + */ |
| 264 | + protected function getConnection() |
| 265 | + { |
| 266 | + return $this->pdo; |
| 267 | + } |
| 268 | +} |
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