380 lines
14 KiB
PHP
380 lines
14 KiB
PHP
<?php
|
|
/**
|
|
* Gutenberg_HTTP_Signaling_Server class
|
|
*
|
|
* @package Gutenberg
|
|
*/
|
|
|
|
/**
|
|
* Gutenberg class that contains an HTTP based signaling server used for collaborative editing.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*/
|
|
class Gutenberg_HTTP_Signaling_Server {
|
|
|
|
|
|
/**
|
|
* Adds a wp_ajax action to handle the signaling server requests.
|
|
*/
|
|
public static function init() {
|
|
$gutenberg_experiments = get_option( 'gutenberg-experiments' );
|
|
if ( ! $gutenberg_experiments || ! array_key_exists( 'gutenberg-sync-collaboration', $gutenberg_experiments ) ) {
|
|
return;
|
|
}
|
|
add_action( 'wp_ajax_gutenberg_signaling_server', array( __CLASS__, 'do_wp_ajax_action' ) );
|
|
}
|
|
|
|
/**
|
|
* Handles a wp_ajax signaling server request.
|
|
*/
|
|
public static function do_wp_ajax_action() {
|
|
if ( empty( $_REQUEST ) || empty( $_REQUEST['subscriber_id'] ) ) {
|
|
die( 'no identifier' );
|
|
}
|
|
|
|
// Contains the subscriber id of the client reading or sending messages.
|
|
$subscriber_id = $_REQUEST['subscriber_id'];
|
|
|
|
// Example inside file: array( 2323232121 => array( 'message hello','handshake message' ) ).
|
|
$subscriber_to_messages_path = get_temp_dir() . DIRECTORY_SEPARATOR . 'subscribers_to_messages.txt';
|
|
|
|
// Example inside file: array( 'doc1: array( 2323232121 ), 'doc2: array( 2323232123, 2323232121 ) ).
|
|
$topics_to_subscribers_path = get_temp_dir() . DIRECTORY_SEPARATOR . 'topics_to_subscribers.txt';
|
|
|
|
if ( 'GET' === $_SERVER['REQUEST_METHOD'] ) {
|
|
static::handle_read_pending_messages( $subscriber_to_messages_path, $subscriber_id );
|
|
} else {
|
|
if ( empty( $_POST ) || empty( $_POST['message'] ) ) {
|
|
die( 'no message' );
|
|
}
|
|
$message = json_decode( wp_unslash( $_POST['message'] ), true );
|
|
if ( ! $message ) {
|
|
die( 'no message' );
|
|
}
|
|
|
|
switch ( $message['type'] ) {
|
|
case 'subscribe':
|
|
static::handle_subscribe_to_topics( $topics_to_subscribers_path, $subscriber_id, $message['topics'] );
|
|
break;
|
|
case 'unsubscribe':
|
|
static::handle_unsubscribe_from_topics( $topics_to_subscribers_path, $subscriber_id, $message['topics'] );
|
|
break;
|
|
case 'publish':
|
|
static::handle_publish_message( $topics_to_subscribers_path, $subscriber_to_messages_path, $subscriber_id, $message );
|
|
break;
|
|
case 'ping':
|
|
static::handle_ping( $subscriber_to_messages_path, $subscriber_id );
|
|
break;
|
|
}
|
|
echo wp_json_encode( array( 'result' => 'ok' ) ), PHP_EOL, PHP_EOL;
|
|
}
|
|
|
|
static::clean_up_old_connections( $topics_to_subscribers_path, $subscriber_to_messages_path, $subscriber_id );
|
|
exit;
|
|
}
|
|
|
|
/**
|
|
* Reads the contents of $fd and returns them deserialized.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param resource $fd A file descriptor.
|
|
*
|
|
* @return array Deserialized contents of fd.
|
|
*/
|
|
private static function get_contents_from_file_descriptor( $fd ) {
|
|
$contents_raw = stream_get_contents( $fd );
|
|
$result = array();
|
|
if ( $contents_raw ) {
|
|
$result = unserialize( $contents_raw );
|
|
}
|
|
return $result;
|
|
}
|
|
|
|
/**
|
|
* Locks a file with an exclusive lock and returns its contents deserialized.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param string $path The path of a file.
|
|
*
|
|
* @return array File descriptor as the first element of the array and the contents of the file as the second element.
|
|
*/
|
|
private static function get_contents_and_lock_file( $path ) {
|
|
$fd = fopen( $path, 'c+' );
|
|
if ( ! $fd ) {
|
|
return array( $fd, null );
|
|
}
|
|
flock( $fd, LOCK_EX );
|
|
return array( $fd, static::get_contents_from_file_descriptor( $fd ) );
|
|
}
|
|
|
|
/**
|
|
* Makes the file descriptor content of $fd equal to the serialization of content.
|
|
* Overwrites what was previously in $fd.
|
|
* Unlocks the file descriptor and closes it.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param resource $fd A file descriptor.
|
|
* @param array $content An array with the contents to serialized and written to the file.
|
|
*/
|
|
private static function save_contents_and_unlock_file( $fd, $content ) {
|
|
static::save_contents_to_file_descriptor( $fd, $content );
|
|
flock( $fd, LOCK_UN );
|
|
fclose( $fd );
|
|
}
|
|
|
|
/**
|
|
* Makes the file descriptor content of $fd equal to the serialization of content.
|
|
* Overwrites what was previously in $fd.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param resource $fd A file descriptor.
|
|
* @param array $content Content to be serialized and written in a file descriptor.
|
|
*/
|
|
private static function save_contents_to_file_descriptor( $fd, $content ) {
|
|
rewind( $fd );
|
|
$data = serialize( $content );
|
|
fwrite( $fd, $data );
|
|
ftruncate( $fd, strlen( $data ) );
|
|
}
|
|
|
|
/**
|
|
* Handles a wp_ajax signaling server request of client that wants to retrieve its messages.
|
|
*
|
|
* It returns the client a response following the
|
|
* {@link https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events#event_stream_format Event stream format}.
|
|
*
|
|
* ```
|
|
* id: <Event ID>
|
|
* retry: <Reconnection time, in ms>
|
|
* event: <The type of event>
|
|
* data: <The message to be sent>
|
|
* ```
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param string $subscriber_to_messages_path The path to the file that contains the messages of the subscribers.
|
|
* @param string $subscriber_id The subscriber id.
|
|
*/
|
|
private static function handle_read_pending_messages( $subscriber_to_messages_path, $subscriber_id ) {
|
|
header( 'Content-Type: text/event-stream' );
|
|
header( 'Cache-Control: no-cache' );
|
|
list( $fd, $subscriber_to_messages ) = static::get_contents_and_lock_file( $subscriber_to_messages_path );
|
|
if ( ! $fd ) {
|
|
$retries = isset( $_COOKIE['signaling_server_retries'] ) ? intval( $_COOKIE['signaling_server_retries'] ) : 0;
|
|
$secure = ( 'https' === parse_url( home_url(), PHP_URL_SCHEME ) );
|
|
setcookie( 'signaling_server_retries', $retries + 1, time() + DAY_IN_SECONDS, SITECOOKIEPATH, '', $secure );
|
|
echo 'id: ' . time() . PHP_EOL;
|
|
echo 'event: error' . PHP_EOL;
|
|
echo 'data: ' . 'Could not open required file.' . PHP_EOL . PHP_EOL;
|
|
echo 'retry: ' . 3000 * pow( 2, $retries ) . PHP_EOL;
|
|
exit;
|
|
}
|
|
|
|
if ( isset( $_COOKIE['signaling_server_retries'] ) ) {
|
|
$secure = ( 'https' === parse_url( home_url(), PHP_URL_SCHEME ) );
|
|
// unset the cookie using a past expiration date.
|
|
setcookie( 'signaling_server_retries', 0, time() - DAY_IN_SECONDS, SITECOOKIEPATH, '', $secure );
|
|
}
|
|
|
|
echo 'retry: 3000' . PHP_EOL;
|
|
if ( isset( $subscriber_to_messages[ $subscriber_id ] ) && count( $subscriber_to_messages[ $subscriber_id ] ) > 0 ) {
|
|
echo 'id: ' . time() . PHP_EOL;
|
|
echo 'event: message' . PHP_EOL;
|
|
echo 'data: ' . wp_json_encode( $subscriber_to_messages[ $subscriber_id ] ) . PHP_EOL . PHP_EOL;
|
|
$subscriber_to_messages[ $subscriber_id ] = array();
|
|
static::save_contents_to_file_descriptor( $fd, $subscriber_to_messages );
|
|
} else {
|
|
echo PHP_EOL;
|
|
}
|
|
flock( $fd, LOCK_UN );
|
|
fclose( $fd );
|
|
}
|
|
|
|
/**
|
|
* Handles a wp_ajax signaling server request of client that wants to subscribe to a set of topics its messages.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param string $topics_to_subscribers_path Topics to subscribers path.
|
|
* @param string $subscriber_id The subscriber id.
|
|
* @param array $topics An array of topics e.g: array( 'doc1', 'doc2' ).
|
|
*/
|
|
private static function handle_subscribe_to_topics( $topics_to_subscribers_path, $subscriber_id, $topics ) {
|
|
list( $fd, $topics_to_subscribers ) = static::get_contents_and_lock_file( $topics_to_subscribers_path );
|
|
if ( ! $fd ) {
|
|
die( 'Could not open required file.' );
|
|
}
|
|
foreach ( $topics as $topic ) {
|
|
if ( ! isset( $topics_to_subscribers[ $topic ] ) ) {
|
|
$topics_to_subscribers[ $topic ] = array();
|
|
}
|
|
$topics_to_subscribers[ $topic ][] = $subscriber_id;
|
|
$topics_to_subscribers[ $topic ] = array_unique( $topics_to_subscribers[ $topic ] );
|
|
}
|
|
static::save_contents_and_unlock_file( $fd, $topics_to_subscribers );
|
|
}
|
|
|
|
/**
|
|
* Handles a wp_ajax signaling server request of client that wants to unsubscribe from a set of topics its messages.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param string $topics_to_subscribers_path Topics to subscribers path.
|
|
* @param string $subscriber_id The subscriber id.
|
|
* @param array $topics An array of topics e.g: array( 'doc1', 'doc2' ).
|
|
*/
|
|
private static function handle_unsubscribe_from_topics( $topics_to_subscribers_path, $subscriber_id, $topics ) {
|
|
list( $fd, $topics_to_subscribers ) = static::get_contents_and_lock_file( $topics_to_subscribers_path );
|
|
if ( ! $fd ) {
|
|
die( 'Could not open required file.' );
|
|
}
|
|
foreach ( $topics as $topic ) {
|
|
if ( $topics_to_subscribers[ $topic ] ) {
|
|
$topics_to_subscribers[ $topic ] = array_diff( $topics_to_subscribers[ $topic ], array( $subscriber_id ) );
|
|
}
|
|
}
|
|
static::save_contents_and_unlock_file( $fd, $topics_to_subscribers );
|
|
}
|
|
|
|
/**
|
|
* Handles a wp_ajax signaling server request of client that wants to publish a message.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param string $topics_to_subscribers_path Topics to subscribers path.
|
|
* @param string $subscriber_to_messages_path The path to the file that contains the messages of the subscribers.
|
|
* @param string $subscriber_id The subscriber id.
|
|
* @param array $message The message associative array.
|
|
*/
|
|
private static function handle_publish_message( $topics_to_subscribers_path, $subscriber_to_messages_path, $subscriber_id, $message ) {
|
|
list( $fd_topics_subscriber, $topics_to_subscribers ) = static::get_contents_and_lock_file( $topics_to_subscribers_path );
|
|
list( $fd_subscriber_to_messages, $subscriber_to_messages ) = static::get_contents_and_lock_file( $subscriber_to_messages_path );
|
|
if ( ! $fd_topics_subscriber || ! $fd_subscriber_to_messages ) {
|
|
die( 'Could not open required file.' );
|
|
}
|
|
$topic = $message['topic'];
|
|
$receivers = $topics_to_subscribers[ $topic ];
|
|
if ( $receivers && count( $receivers ) > 0 ) {
|
|
$message['clients'] = count( $receivers );
|
|
foreach ( $receivers as $receiver ) {
|
|
if ( ! isset( $subscriber_to_messages[ $receiver ] ) ) {
|
|
$subscriber_to_messages[ $receiver ] = array();
|
|
}
|
|
$subscriber_to_messages[ $receiver ][] = $message;
|
|
}
|
|
static::save_contents_to_file_descriptor( $fd_subscriber_to_messages, $subscriber_to_messages );
|
|
}
|
|
flock( $fd_subscriber_to_messages, LOCK_UN );
|
|
fclose( $fd_subscriber_to_messages );
|
|
flock( $fd_topics_subscriber, LOCK_UN );
|
|
fclose( $fd_topics_subscriber );
|
|
}
|
|
|
|
/**
|
|
* Handles a wp_ajax signaling server request for the ping of a client.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param string $subscriber_to_messages_path The path to the file that contains the messages of the subscribers.
|
|
* @param string $subscriber_id The subscriber id.
|
|
*/
|
|
private static function handle_ping( $subscriber_to_messages_path, $subscriber_id ) {
|
|
list( $fd_subscriber_to_messages, $subscriber_to_messages ) = static::get_contents_and_lock_file( $subscriber_to_messages_path );
|
|
if ( ! $fd_subscriber_to_messages ) {
|
|
die( 'Could not open required file.' );
|
|
}
|
|
if ( ! $subscriber_to_messages[ $subscriber_id ] ) {
|
|
$subscriber_to_messages[ $subscriber_id ] = array();
|
|
}
|
|
$subscriber_to_messages[ $subscriber_id ][] = array( 'type' => 'pong' );
|
|
static::save_contents_and_unlock_file( $fd_subscriber_to_messages, $subscriber_to_messages );
|
|
}
|
|
|
|
|
|
/**
|
|
* Deletes messages and subscriber information of clients that have not interacted with the signaling server in a long time.
|
|
*
|
|
* @access private
|
|
* @internal
|
|
*
|
|
* @param string $topics_to_subscribers_path The path to the file that contains the subscribers of the topics.
|
|
* @param string $subscriber_to_messages_path The path to the file that contains the messages of the subscribers.
|
|
* @param string $connected_subscriber_id The subscriber id.
|
|
*/
|
|
private static function clean_up_old_connections( $topics_to_subscribers_path, $subscriber_to_messages_path, $connected_subscriber_id ) {
|
|
$subscribers_to_last_connection_path = get_temp_dir() . DIRECTORY_SEPARATOR . 'subscribers_to_last_connection.txt';
|
|
// Example: array( 2323232121 => 34343433323(timestamp) ).
|
|
|
|
$fd_subscribers_last_connection = fopen( $subscribers_to_last_connection_path, 'c+' );
|
|
if ( ! $fd_subscribers_last_connection ) {
|
|
die( 'Could not open required file.' );
|
|
}
|
|
flock( $fd_subscribers_last_connection, LOCK_EX );
|
|
$subscribers_to_last_connection_time = static::get_contents_from_file_descriptor( $fd_subscribers_last_connection );
|
|
$subscribers_to_last_connection_time[ $connected_subscriber_id ] = time();
|
|
$needs_cleanup = false;
|
|
foreach ( $subscribers_to_last_connection_time as $subscriber_id => $last_connection_time ) {
|
|
// cleanup connections older than 1 hour.
|
|
if ( $last_connection_time < time() - 1 * 60 * 60 ) {
|
|
unset( $subscribers_to_last_connection_time[ $subscriber_id ] );
|
|
$needs_cleanup = true;
|
|
}
|
|
}
|
|
static::save_contents_to_file_descriptor( $fd_subscribers_last_connection, $subscribers_to_last_connection_time );
|
|
|
|
if ( $needs_cleanup ) {
|
|
$fd_subscriber_messages = fopen( $subscriber_to_messages_path, 'c+' );
|
|
if ( ! $fd_subscriber_messages ) {
|
|
die( 'Could not open required file.' );
|
|
}
|
|
flock( $fd_subscriber_messages, LOCK_EX );
|
|
$subscriber_to_messages = static::get_contents_from_file_descriptor( $fd_subscriber_messages );
|
|
foreach ( $subscriber_to_messages as $subscriber_id => $messages ) {
|
|
if ( ! isset( $subscribers_to_last_connection_time[ $subscriber_id ] ) ) {
|
|
unset( $subscriber_to_messages[ $subscriber_id ] );
|
|
}
|
|
}
|
|
static::save_contents_to_file_descriptor( $fd_subscriber_messages, $subscriber_to_messages );
|
|
|
|
$fd_topics_subscriber = fopen( $topics_to_subscribers_path, 'c+' );
|
|
if ( ! $fd_topics_subscriber ) {
|
|
die( 'Could not open required file.' );
|
|
}
|
|
flock( $fd_topics_subscriber, LOCK_EX );
|
|
$topics_to_subscribers = static::get_contents_from_file_descriptor( $fd_topics_subscriber );
|
|
foreach ( $topics_to_subscribers as $topic => $subscribers ) {
|
|
foreach ( $subscribers as $subscriber_id ) {
|
|
if ( ! isset( $subscribers_to_last_connection_time[ $subscriber_id ] ) ) {
|
|
$topics_to_subscribers[ $topic ] = array_diff( $topics_to_subscribers[ $topic ], array( $subscriber_id ) );
|
|
}
|
|
}
|
|
}
|
|
static::save_contents_to_file_descriptor( $fd_topics_subscriber, $topics_to_subscribers );
|
|
|
|
flock( $fd_subscriber_messages, LOCK_UN );
|
|
fclose( $fd_subscriber_messages );
|
|
|
|
flock( $fd_topics_subscriber, LOCK_UN );
|
|
fclose( $fd_topics_subscriber );
|
|
}
|
|
|
|
flock( $fd_subscribers_last_connection, LOCK_UN );
|
|
fclose( $fd_subscribers_last_connection );
|
|
}
|
|
}
|
|
|
|
Gutenberg_HTTP_Signaling_Server::init();
|
