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PdoSessionHandler: fix advisory lock for pgsql #24367

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Merged
merged 1 commit into from
Sep 29, 2017
Merged

PdoSessionHandler: fix advisory lock for pgsql #24367

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33 changes: 27 additions & 6 deletions src/Symfony/Component/HttpFoundation/Session/Storage/Handler/PdoSessionHandler.php
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Original file line number Diff line number Diff line change
Expand Up @@ -580,11 +580,11 @@ private function doAdvisoryLock($sessionId)
return $releaseStmt;
case 'pgsql':
// Obtaining an exclusive session level advisory lock requires an integer key.
// So we convert the HEX representation of the session id to an integer.
// Since integers are signed, we have to skip one hex char to fit in the range.
if (4 === PHP_INT_SIZE) {
$sessionInt1 = hexdec(substr($sessionId, 0, 7));
$sessionInt2 = hexdec(substr($sessionId, 7, 7));
// When session.sid_bits_per_character > 4, the session id can contain non-hex-characters.
// So we cannot just use hexdec().
if (4 === \PHP_INT_SIZE) {
$sessionInt1 = $this->convertStringToInt($sessionId);
$sessionInt2 = $this->convertStringToInt(substr($sessionId, 4, 4));

$stmt = $this->pdo->prepare('SELECT pg_advisory_lock(:key1, :key2)');
$stmt->bindValue(':key1', $sessionInt1, \PDO::PARAM_INT);
Expand All @@ -595,7 +595,7 @@ private function doAdvisoryLock($sessionId)
$releaseStmt->bindValue(':key1', $sessionInt1, \PDO::PARAM_INT);
$releaseStmt->bindValue(':key2', $sessionInt2, \PDO::PARAM_INT);
} else {
$sessionBigInt = hexdec(substr($sessionId, 0, 15));
$sessionBigInt = $this->convertStringToInt($sessionId);

$stmt = $this->pdo->prepare('SELECT pg_advisory_lock(:key)');
$stmt->bindValue(':key', $sessionBigInt, \PDO::PARAM_INT);
Expand All @@ -613,6 +613,27 @@ private function doAdvisoryLock($sessionId)
}
}

/**
* Encodes the first 4 (when PHP_INT_SIZE == 4) or 8 characters of the string as an integer.
*
* Keep in mind, PHP integers are signed.
*
* @param string $string
*
* @return int
*/
private function convertStringToInt($string)
{
if (4 === \PHP_INT_SIZE) {
return (ord($string[3]) << 24) + (ord($string[2]) << 16) + (ord($string[1]) << 8) + ord($string[0]);
}

$int1 = (ord($string[7]) << 24) + (ord($string[6]) << 16) + (ord($string[5]) << 8) + ord($string[4]);
$int2 = (ord($string[3]) << 24) + (ord($string[2]) << 16) + (ord($string[1]) << 8) + ord($string[0]);

return $int2 + ($int1 << 32);
}

/**
* Return a locking or nonlocking SQL query to read session information.
*
Expand Down