PHP 8.3.4 Released!

A classe SessionHandlerInterface

(PHP 5 >= 5.4.0, PHP 7, PHP 8)

Introdução

SessionHandlerInterface é uma interface que define o protótipo mínimo para criar um manipulador de sessão personalizado. Para passar um manipulador de sessão personalizado para session_set_save_handler() usando invocação OOP (Orientada à Objetos), a classe deve implementar esta interface.

Note que os métodos de callbacks desta classe são projetos para serem chamados internamente pelo PHP e não para serem chamados pelo código do usuário.

Resumo da Interface

interface SessionHandlerInterface {
/* Métodos */
public close(): bool
public destroy(string $id): bool
public gc(int $max_lifetime): int|false
public open(string $path, string $name): bool
public read(string $id): string|false
public write(string $id, string $data): bool
}

Exemplo #1 Exemplo usando SessionHandlerInterface

O exemplo a seguir apresenta um armazenamento de sessão baseada em arquivos semelhante aos manipuladores de gravação de sessão padrões do PHP files. Este exemplo poderia ser facilmente estendido para cobrir armazenamento em banco de dados usando sua engine de banco de dados favorita que seja suportada pelo PHP.

Note que é usado orientação à objetos com session_set_save_handler() e a função de encerramento (register_shutdown) é registrada usando sua respectiva flag. Isto é aconselhável ao registrar objetos como manipuladores de gravação de sessão.

Cuidado

Por brevidade, este exemplo omite a validação de entrada. No entanto, o Os parâmetros $id são, na verdade, valores fornecidos pelo usuário que exigem validação/sanitização adequada para evitar vulnerabilidades, como problemas de passagem de caminho. Portanto, não use este exemplo não modificado em ambientes de produção.

<?php
class MySessionHandler implements SessionHandlerInterface
{
private
$savePath;

public function
open($savePath, $sessionName): bool
{
$this->savePath = $savePath;
if (!
is_dir($this->savePath)) {
mkdir($this->savePath, 0777);
}

return
true;
}

public function
close(): bool
{
return
true;
}

#[
\ReturnTypeWillChange]
public function
read($id)
{
return (string)@
file_get_contents("$this->savePath/sess_$id");
}

public function
write($id, $data): bool
{
return
file_put_contents("$this->savePath/sess_$id", $data) === false ? false : true;
}

public function
destroy($id): bool
{
$file = "$this->savePath/sess_$id";
if (
file_exists($file)) {
unlink($file);
}

return
true;
}

#[
\ReturnTypeWillChange]
public function
gc($maxlifetime)
{
foreach (
glob("$this->savePath/sess_*") as $file) {
if (
filemtime($file) + $maxlifetime < time() && file_exists($file)) {
unlink($file);
}
}

return
true;
}
}

$handler = new MySessionHandler();
session_set_save_handler($handler, true);
session_start();

// proceder para definir e recuperar valores pela chave de $_SESSION

Índice

add a note

User Contributed Notes 8 notes

up
24
ohcc at 163 dot com
6 years ago
As of PHP 7.0, you can implement SessionUpdateTimestampHandlerInterface to
define your own session id validating method like validate_sid and the timestamp updating method like update_timestamp in the non-OOP prototype of session_set_save_handler().

SessionUpdateTimestampHandlerInterface is a new interface introduced in PHP 7.0, which has not been documented yet. It has two abstract methods: SessionUpdateTimestampHandlerInterface :: validateId($sessionId) and SessionUpdateTimestampHandlerInterface :: updateTimestamp($sessionId, $sessionData).

<?php
/*
@author Wu Xiancheng
Code structure for PHP 7.0+ only because SessionUpdateTimestampHandlerInterface is introduced in PHP 7.0
With this class you can validate php session id and update the timestamp of php session data
with the OOP prototype of session_set_save_handler() in PHP 7.0+
*/
class PHPSessionXHandler implements SessionHandlerInterface, SessionUpdateTimestampHandlerInterface {
public function
close(){
// return value should be true for success or false for failure
// ...
}
public function
destroy($sessionId){
// return value should be true for success or false for failure
// ...
}
public function
gc($maximumLifetime){
// return value should be true for success or false for failure
// ...
}
public function
open($sessionSavePath, $sessionName){
// return value should be true for success or false for failure
// ...
}
public function
read($sessionId){
// return value should be the session data or an empty string
// ...
}
public function
write($sessionId, $sessionData){
// return value should be true for success or false for failure
// ...
}
public function
create_sid(){
// available since PHP 5.5.1
// invoked internally when a new session id is needed
// no parameter is needed and return value should be the new session id created
// ...
}
public function
validateId($sessionId){
// implements SessionUpdateTimestampHandlerInterface::validateId()
// available since PHP 7.0
// return value should be true if the session id is valid otherwise false
// if false is returned a new session id will be generated by php internally
// ...
}
public function
updateTimestamp($sessionId, $sessionData){
// implements SessionUpdateTimestampHandlerInterface::validateId()
// available since PHP 7.0
// return value should be true for success or false for failure
// ...
}
}
?>
up
6
ohcc at 163 dot com
6 years ago
The non-OOP prototype of session_set_save_handler() supports validate_sid and update_timestamp as of PHP 7.0 while the OOP prototype doesn't even in PHP 7.2. However the OOP prototype does support create_sid since PHP 5.5.1.

validate_sid($sessionId)
This callback is to validate $sessionId. Its return value should be true for valid session id $sessionId or false for invalid session id $sessionId. If false is returned, a new session id is generated to replace the invalid session id $sessionId.

update_timestamp($sessionId)
This call back is to update timestamp, and its return value should be true for success or false for failure.
up
1
ohcc at 163 dot com
6 years ago
As of PHP 5.5.1, another method create_sid() is supported. It will be called when session_regenerate_id() is invoked.

SessionHandlerInterface {
/* Methods */
abstract public bool close ( void )
abstract public bool create_sid ( void )
abstract public bool destroy ( string $session_id )
abstract public bool gc ( int $maxlifetime )
abstract public bool open ( string $save_path , string $session_name )
abstract public string read ( string $session_id )
abstract public bool write ( string $session_id , string $session_data )
}
up
4
avenidagez at foro5 dot com
9 years ago
Note that session_start( ) calls open then read and the class returns true for open and the value of session or empty for read.
Well, then there is no catch for errors, this is, session_start() must return false on failure, but that is not the case for the class implementation on method open, no matter if you return true or false or whatever from open, it is ignored by session_start() function and proceeds to read method
A bug?, if open returns false, session_start() should stop the next step (read) and return itself false

if(session_start()) ...code
else exit( );

So forget about session_start() return value, you need to implement an error catch routine and exit() in case of failure on open method
up
5
warxcell at gmail dot com
11 years ago
You should prepend <b>\</b> before class name, to tell php its from root namespace.
up
2
tony at marston-home dot demon dot co dot uk
5 years ago
Your custom session handler should not contain calls to any of the session functions, such as session_name() or session_id(), as the relevant values are passed as arguments on various handler methods. Attempting to obtain values from alternative sources may not work as expected.
up
0
ohcc at 163 dot com
3 years ago
If you want to use type declarations in your own session handling class, don't "implements" the SessionHandlerInterface, SessionIdInterface, or SessinUpdateTimestampInterface, otherwise you will get a fatal error saying that declaration of the class method must be compatible with the interface method.

a bad example
<?php
class SessionWuXianchengHandler implements SessionHandlerInterface {
public function
open(string $sessionPath, string $sessionName) : bool {
}
......
}
?>

a good example
<?php
class SessionWuXianchengHandler {
public function
open(string $sessionPath, string $sessionName) : bool {
}
......
}
?>
up
-5
StanE
8 years ago
I think there is a small "error" in the example of the class MySessionHandler in method gc(). It uses the function filemtime() whose return value is cached by PHP. Add the following line inside the foreach block in the gc() method:

clearstatcache(true, $file);
To Top