sodium_crypto_generichash_update

<?php
$messages = [random_bytes(32), random_bytes(32), random_bytes(16)];
$state = sodium_crypto_generichash_init();
foreach ($messages as $message) {
    sodium_crypto_generichash_update($state, $message);
}
$final = sodium_crypto_generichash_final($state);
var_dump(sodium_bin2hex($final));

$allAtOnce = sodium_crypto_generichash(implode('', $messages));
var_dump(sodium_bin2hex($allAtOnce));
?>