Method

Creates a publisher: what is written to $publisher is delivered to every subscription of $subscribers.

Description#

public static phasync::publisher(
    ?SubscribersInterface &$subscribers,
    ?WriteChannelInterface &$publisher
): void

Each subscription receives the messages written after it was made, in order, and a slow subscription does not hold back the others. A subscription made later does not see earlier messages. Writing with no subscriber succeeds. Closing the publisher ends the subscriptions once they have read what was written.

A publisher forwards messages in a phasync::service coroutine, which ends when the publisher is closed or its write end is dropped, and is cancelled when the outermost run() has nothing else left to do.

Parameters#

$subscribers ?SubscribersInterface

Receives the object to subscribe with

$publisher ?WriteChannelInterface

Receives the writing end

Examples#

phasync::run(function () {
    phasync::publisher($subscribers, $publisher);

    foreach ([1, 2] as $i) {
        $subscription = $subscribers->subscribe();
        phasync::go(function () use ($subscription, $i) {
            foreach ($subscription as $event) {
                echo "subscriber $i got $event\n";
            }
        });
    }
    $publisher->write('deployed');
    $publisher->close();
});

See also#