function find_diaspora_person_by_handle($handle)
{
$update = false;
$r = q("select * from fcontact where network = '%s' and addr = '%s' limit 1", dbesc(NETWORK_DIASPORA), dbesc($handle));
if (count($r)) {
logger('find_diaspora_person_by handle: in cache ' . print_r($r, true), LOGGER_DEBUG);
// update record occasionally so it doesn't get stale
$d = strtotime($r[0]['updated'] . ' +00:00');
if ($d > strtotime('now - 14 days')) {
return $r[0];
}
$update = true;
}
logger('find_diaspora_person_by_handle: refresh', LOGGER_DEBUG);
require_once 'include/Scrape.php';
$r = probe_url($handle, PROBE_DIASPORA);
if (count($r) && $r['network'] === NETWORK_DIASPORA) {
add_fcontact($r, $update);
return $r;
}
return false;
}
function find_diaspora_person_by_handle($handle)
{
$person = false;
$update = false;
$got_lock = false;
$endlessloop = 0;
$maxloops = 10;
do {
$r = q("select * from fcontact where network = '%s' and addr = '%s' limit 1", dbesc(NETWORK_DIASPORA), dbesc($handle));
if (count($r)) {
$person = $r[0];
logger('find_diaspora_person_by handle: in cache ' . print_r($r, true), LOGGER_DEBUG);
// update record occasionally so it doesn't get stale
$d = strtotime($person['updated'] . ' +00:00');
if ($d < strtotime('now - 14 days')) {
$update = true;
}
}
// FETCHING PERSON INFORMATION FROM REMOTE SERVER
//
// If the person isn't in our 'fcontact' table, or if he/she is but
// his/her information hasn't been updated for more than 14 days, then
// we want to fetch the person's information from the remote server.
//
// Note that $person isn't changed by this block of code unless the
// person's information has been successfully fetched from the remote
// server. So if $person was 'false' to begin with (because he/she wasn't
// in the local cache), it'll stay false, and if $person held the local
// cache information to begin with, it'll keep that information. That way
// if there's a problem with the remote fetch, we can at least use our
// cached information--it's better than nothing.
if (!$person || $update) {
// Lock the function to prevent race conditions if multiple items
// come in at the same time from a person who doesn't exist in
// fcontact
//
// Don't loop forever. On the last loop, try to create the contact
// whether the function is locked or not. Maybe the locking thread
// has died or something. At any rate, a duplicate in 'fcontact'
// is a much smaller problem than a deadlocked thread
$got_lock = lock_function('find_diaspora_person_by_handle', false);
if ($endlessloop + 1 >= $maxloops) {
$got_lock = true;
}
if ($got_lock) {
logger('find_diaspora_person_by_handle: create or refresh', LOGGER_DEBUG);
require_once 'include/Scrape.php';
$r = probe_url($handle, PROBE_DIASPORA);
// Note that Friendica contacts can return a "Diaspora person"
// if Diaspora connectivity is enabled on their server
if (count($r) && $r['network'] === NETWORK_DIASPORA) {
add_fcontact($r, $update);
$person = $r;
}
unlock_function('find_diaspora_person_by_handle');
} else {
logger('find_diaspora_person_by_handle: couldn\'t lock function', LOGGER_DEBUG);
if (!$person) {
block_on_function_lock('find_diaspora_person_by_handle');
}
}
}
} while (!$person && !$got_lock && ++$endlessloop < $maxloops);
// We need to try again if the person wasn't in 'fcontact' but the function was locked.
// The fact that the function was locked may mean that another process was creating the
// person's record. It could also mean another process was creating or updating an unrelated
// person.
//
// At any rate, we need to keep trying until we've either got the person or had a chance to
// try to fetch his/her remote information. But we don't want to block on locking the
// function, because if the other process is creating the record, then when we acquire the lock
// we'll dive right into creating another, duplicate record. We DO want to at least wait
// until the lock is released, so we don't flood the database with requests.
//
// If the person was in the 'fcontact' table, don't try again. It's not worth the time, since
// we do have some information for the person
return $person;
}
