467 lines
15 KiB
PHP

<?php
/**
* ActivityPub Dispatcher Class.
*
* @package Activitypub
*/
namespace Activitypub;
use Activitypub\Activity\Activity;
use Activitypub\Collection\Followers;
use Activitypub\Collection\Outbox;
/**
* ActivityPub Dispatcher Class.
*
* @author Matthias Pfefferle
*
* @see https://www.w3.org/TR/activitypub/
*/
class Dispatcher {
/**
* Batch size.
*
* @var int
*/
public static $batch_size = ACTIVITYPUB_OUTBOX_PROCESSING_BATCH_SIZE;
/**
* Callback for the async batch processing.
*
* @var array
*/
public static $callback = array( self::class, 'send_to_followers' );
/**
* Error codes that qualify for a retry.
*
* @see https://github.com/tfredrich/RestApiTutorial.com/blob/fd08b0f67f07450521d143b123cd6e1846cb2e3b/content/advanced/responses/retries.md
* @var int[]
*/
public static $retry_error_codes = array( 408, 429, 500, 502, 503, 504 );
/**
* Initialize the class, registering WordPress hooks.
*/
public static function init() {
\add_action( 'activitypub_process_outbox', array( self::class, 'process_outbox' ) );
// Default filters to add Inboxes to sent to.
\add_filter( 'activitypub_additional_inboxes', array( self::class, 'add_inboxes_by_mentioned_actors' ), 10, 3 );
\add_filter( 'activitypub_additional_inboxes', array( self::class, 'add_inboxes_of_replied_urls' ), 10, 3 );
\add_filter( 'activitypub_additional_inboxes', array( self::class, 'add_inboxes_of_relays' ), 10, 3 );
// Fallback for `activitypub_send_to_inboxes` filter.
\add_filter(
'activitypub_additional_inboxes',
function ( $inboxes, $actor_id, $activity ) {
/**
* Filters the list of interactees inboxes to send the Activity to.
*
* @param array $inboxes The list of inboxes to send to.
* @param int $actor_id The actor ID.
* @param Activity $activity The ActivityPub Activity.
*
* @deprecated 5.2.0 Use `activitypub_additional_inboxes` instead.
* @deprecated 5.4.0 Use `activitypub_additional_inboxes` instead.
*/
$inboxes = \apply_filters_deprecated( 'activitypub_send_to_inboxes', array( $inboxes, $actor_id, $activity ), '5.2.0', 'activitypub_additional_inboxes' );
$inboxes = \apply_filters_deprecated( 'activitypub_interactees_inboxes', array( $inboxes, $actor_id, $activity ), '5.4.0', 'activitypub_additional_inboxes' );
return $inboxes;
},
10,
3
);
}
/**
* Process the outbox.
*
* @param int $id The outbox ID.
*/
public static function process_outbox( $id ) {
$outbox_item = \get_post( $id );
// If the activity is not a post, return.
if ( ! $outbox_item ) {
return;
}
$actor = Outbox::get_actor( $outbox_item );
if ( \is_wp_error( $actor ) ) {
// If the actor is not found, publish the post and don't try again.
\wp_publish_post( $outbox_item );
return;
}
$activity = Outbox::get_activity( $outbox_item );
// Send to mentioned and replied-to users. Everyone other than followers.
self::send_to_additional_inboxes( $activity, $actor->get__id(), $outbox_item );
if ( self::should_send_to_followers( $activity, $actor, $outbox_item ) ) {
Scheduler::async_batch(
self::$callback,
$outbox_item->ID,
self::$batch_size,
\get_post_meta( $outbox_item->ID, '_activitypub_outbox_offset', true ) ?: 0 // phpcs:ignore
);
} else {
// No followers to process for this update. We're done.
\wp_publish_post( $outbox_item );
\delete_post_meta( $outbox_item->ID, '_activitypub_outbox_offset' );
}
}
/**
* Asynchronously runs batch processing routines.
*
* @param int $outbox_item_id The Outbox item ID.
* @param int $batch_size Optional. The batch size. Default ACTIVITYPUB_OUTBOX_PROCESSING_BATCH_SIZE.
* @param int $offset Optional. The offset. Default 0.
*
* @return array|void The next batch of followers to process, or void if done.
*/
public static function send_to_followers( $outbox_item_id, $batch_size = ACTIVITYPUB_OUTBOX_PROCESSING_BATCH_SIZE, $offset = 0 ) {
$json = Outbox::get_activity( $outbox_item_id )->to_json();
$actor = Outbox::get_actor( \get_post( $outbox_item_id ) );
$inboxes = Followers::get_inboxes_for_activity( $json, $actor->get__id(), $batch_size, $offset );
$retries = self::send_to_inboxes( $inboxes, $outbox_item_id );
// Retry failed inboxes.
if ( ! empty( $retries ) ) {
self::schedule_retry( $retries, $outbox_item_id );
}
if ( is_countable( $inboxes ) && count( $inboxes ) < $batch_size ) {
\delete_post_meta( $outbox_item_id, '_activitypub_outbox_offset' );
/**
* Fires when the followers are complete.
*
* @param array $inboxes The inboxes.
* @param string $json The ActivityPub Activity JSON
* @param int $actor_id The actor ID.
* @param int $outbox_item_id The Outbox item ID.
* @param int $batch_size The batch size.
* @param int $offset The offset.
*/
\do_action( 'activitypub_outbox_processing_complete', $inboxes, $json, $actor->get__id(), $outbox_item_id, $batch_size, $offset );
// No more followers to process for this update.
\wp_publish_post( $outbox_item_id );
} else {
\update_post_meta( $outbox_item_id, '_activitypub_outbox_offset', $offset + $batch_size );
/**
* Fires when the batch of followers is complete.
*
* @param array $inboxes The inboxes.
* @param string $json The ActivityPub Activity JSON
* @param int $actor_id The actor ID.
* @param int $outbox_item_id The Outbox item ID.
* @param int $batch_size The batch size.
* @param int $offset The offset.
*/
\do_action( 'activitypub_outbox_processing_batch_complete', $inboxes, $json, $actor->get__id(), $outbox_item_id, $batch_size, $offset );
return array( $outbox_item_id, $batch_size, $offset + $batch_size );
}
}
/**
* Retry sending to followers.
*
* @param string $transient_key The key to retrieve retry inboxes.
* @param int $outbox_item_id The Outbox item ID.
* @param int $attempt The attempt number.
*/
public static function retry_send_to_followers( $transient_key, $outbox_item_id, $attempt = 1 ) {
$inboxes = \get_transient( $transient_key );
if ( false === $inboxes ) {
return;
}
// Delete the transient as we no longer need it.
\delete_transient( $transient_key );
$retries = self::send_to_inboxes( $inboxes, $outbox_item_id );
// Retry failed inboxes.
if ( ++$attempt < 3 && ! empty( $retries ) ) {
self::schedule_retry( $retries, $outbox_item_id, $attempt );
}
}
/**
* Send to inboxes.
*
* @param array $inboxes The inboxes to notify.
* @param int $outbox_item_id The Outbox item ID.
* @return array The failed inboxes.
*/
private static function send_to_inboxes( $inboxes, $outbox_item_id ) {
$json = Outbox::get_activity( $outbox_item_id )->to_json();
$actor = Outbox::get_actor( \get_post( $outbox_item_id ) );
$retries = array();
/**
* Fires before sending an Activity to inboxes.
*
* @param string $json The ActivityPub Activity JSON.
* @param array $inboxes The inboxes to send to.
* @param int $outbox_item_id The Outbox item ID.
*/
\do_action( 'activitypub_pre_send_to_inboxes', $json, $inboxes, $outbox_item_id );
foreach ( $inboxes as $inbox ) {
$result = safe_remote_post( $inbox, $json, $actor->get__id() );
if ( is_wp_error( $result ) && in_array( $result->get_error_code(), self::$retry_error_codes, true ) ) {
$retries[] = $inbox;
}
/**
* Fires after an Activity has been sent to an inbox.
*
* @param array $result The result of the remote post request.
* @param string $inbox The inbox URL.
* @param string $json The ActivityPub Activity JSON.
* @param int $actor_id The actor ID.
* @param int $outbox_item_id The Outbox item ID.
*/
\do_action( 'activitypub_sent_to_inbox', $result, $inbox, $json, $actor->get__id(), $outbox_item_id );
}
return $retries;
}
/**
* Schedule a retry.
*
* @param array $retries The inboxes to retry.
* @param int $outbox_item_id The Outbox item ID.
* @param int $attempt Optional. The attempt number. Default 1.
*/
private static function schedule_retry( $retries, $outbox_item_id, $attempt = 1 ) {
$transient_key = 'activitypub_retry_' . \wp_generate_password( 12, false );
\set_transient( $transient_key, $retries, WEEK_IN_SECONDS );
\wp_schedule_single_event(
\time() + ( $attempt * $attempt * HOUR_IN_SECONDS ),
'activitypub_async_batch',
array(
array( self::class, 'retry_send_to_followers' ),
$transient_key,
$outbox_item_id,
$attempt,
)
);
}
/**
* Send an Activity to a custom list of inboxes, like mentioned users or replied-to posts.
*
* For all custom implementations, please use the `activitypub_additional_inboxes` filter.
*
* @param Activity $activity The ActivityPub Activity.
* @param int $actor_id The actor ID.
* @param \WP_Post $outbox_item The WordPress object.
*/
private static function send_to_additional_inboxes( $activity, $actor_id, $outbox_item = null ) {
/**
* Filters the list of inboxes to send the Activity to.
*
* @param array $inboxes The list of inboxes to send to.
* @param int $actor_id The actor ID.
* @param Activity $activity The ActivityPub Activity.
*/
$inboxes = apply_filters( 'activitypub_additional_inboxes', array(), $actor_id, $activity );
$inboxes = array_unique( $inboxes );
$retries = self::send_to_inboxes( $inboxes, $outbox_item->ID );
// Retry failed inboxes.
if ( ! empty( $retries ) ) {
self::schedule_retry( $retries, $outbox_item->ID );
}
}
/**
* Default filter to add Inboxes of Mentioned Actors
*
* @param array $inboxes The list of Inboxes.
* @param int $actor_id The WordPress Actor-ID.
* @param Activity $activity The ActivityPub Activity.
*
* @return array The filtered Inboxes.
*/
public static function add_inboxes_by_mentioned_actors( $inboxes, $actor_id, $activity ) {
$cc = $activity->get_cc() ?? array();
$to = $activity->get_to() ?? array();
$audience = array_merge( $cc, $to );
// Remove "public placeholder" and "same domain" from the audience.
$audience = array_filter(
$audience,
function ( $actor ) {
return 'https://www.w3.org/ns/activitystreams#Public' !== $actor && ! is_same_domain( $actor );
}
);
if ( $audience ) {
$mentioned_inboxes = Mention::get_inboxes( $audience );
return array_merge( $inboxes, $mentioned_inboxes );
}
return $inboxes;
}
/**
* Default filter to add Inboxes of Posts that are set as `in-reply-to`
*
* @param array $inboxes The list of Inboxes.
* @param int $actor_id The WordPress Actor-ID.
* @param Activity $activity The ActivityPub Activity.
*
* @return array The filtered Inboxes
*/
public static function add_inboxes_of_replied_urls( $inboxes, $actor_id, $activity ) {
$in_reply_to = $activity->get_in_reply_to();
if ( ! $in_reply_to ) {
return $inboxes;
}
if ( ! is_array( $in_reply_to ) ) {
$in_reply_to = array( $in_reply_to );
}
foreach ( $in_reply_to as $url ) {
// No need to self-notify.
if ( is_same_domain( $url ) ) {
continue;
}
$object = Http::get_remote_object( $url );
if (
! $object ||
\is_wp_error( $object ) ||
empty( $object['attributedTo'] )
) {
continue;
}
$actor = object_to_uri( $object['attributedTo'] );
$actor = Http::get_remote_object( $actor );
if ( ! $actor || \is_wp_error( $actor ) ) {
continue;
}
if ( ! empty( $actor['endpoints']['sharedInbox'] ) ) {
$inboxes[] = $actor['endpoints']['sharedInbox'];
} elseif ( ! empty( $actor['inbox'] ) ) {
$inboxes[] = $actor['inbox'];
}
}
return $inboxes;
}
/**
* Adds Blog Actor inboxes to Updates so the Blog User's followers are notified of edits.
*
* @deprecated 5.2.0 Use {@see Followers::maybe_add_inboxes_of_blog_user} instead.
*
* @param array $inboxes The list of Inboxes.
* @param int $actor_id The WordPress Actor-ID.
* @param Activity $activity The ActivityPub Activity.
*
* @return array The filtered Inboxes.
*/
public static function maybe_add_inboxes_of_blog_user( $inboxes, $actor_id, $activity ) { // phpcs:ignore
_deprecated_function( __METHOD__, '5.2.0', 'Followers::maybe_add_inboxes_of_blog_user' );
return $inboxes;
}
/**
* Check if passed Activity is public.
*
* @param Activity $activity The Activity object.
* @param \Activitypub\Model\User|\Activitypub\Model\Blog $actor The Actor object.
* @param \WP_Post $outbox_item The Outbox item.
*
* @return boolean True if public, false if not.
*/
protected static function should_send_to_followers( $activity, $actor, $outbox_item ) {
// Check if follower endpoint is set.
$cc = $activity->get_cc() ?? array();
$to = $activity->get_to() ?? array();
$audience = array_merge( $cc, $to );
$send = (
// Check if activity is public.
in_array( 'https://www.w3.org/ns/activitystreams#Public', $audience, true ) ||
// ...or check if follower endpoint is set.
in_array( $actor->get_followers(), $audience, true )
);
if ( $send ) {
$followers = Followers::get_inboxes_for_activity( $activity->to_json(), $actor->get__id() );
// Only send if there are followers to send to.
$send = ! is_countable( $followers ) || 0 < count( $followers );
}
/**
* Filters whether to send an Activity to followers.
*
* @param bool $send_activity_to_followers Whether to send the Activity to followers.
* @param Activity $activity The ActivityPub Activity.
* @param int $actor_id The actor ID.
* @param \WP_Post $outbox_item The WordPress object.
*/
return apply_filters( 'activitypub_send_activity_to_followers', $send, $activity, $actor->get__id(), $outbox_item );
}
/**
* Add Inboxes of Relays.
*
* @param array $inboxes The list of Inboxes.
* @param int $actor_id The Actor-ID.
* @param Activity $activity The ActivityPub Activity.
*
* @return array The filtered Inboxes.
*/
public static function add_inboxes_of_relays( $inboxes, $actor_id, $activity ) {
// Check if follower endpoint is set.
$cc = $activity->get_cc() ?? array();
$to = $activity->get_to() ?? array();
$audience = array_merge( $cc, $to );
// Check if activity is public.
if ( ! in_array( 'https://www.w3.org/ns/activitystreams#Public', $audience, true ) ) {
return $inboxes;
}
$relays = \get_option( 'activitypub_relays', array() );
if ( empty( $relays ) ) {
return $inboxes;
}
return array_merge( $inboxes, $relays );
}
}