function get_day_id($calendar, $day, $month, $year)
{
global $conn;
$date = date('Y-m-d', strtotime("{$month}/{$day}/{$year}"));
if (!$date || !$calendar) {
return null;
}
$can_see = viewer_can_see_calendar($calendar);
if (!$can_see) {
// can be null or false, see comment above
return $can_see;
}
$result = $conn->query("SELECT id FROM days WHERE date = '{$date}' AND calendar = {$calendar}");
$existing_row = $result->fetch_assoc();
if ($existing_row) {
return intval($existing_row['id']);
}
$conn->query("INSERT INTO ids(table_name) VALUES('days')");
$new_day_id = $conn->insert_id;
$conn->query("INSERT INTO days(id, date, calendar) " . "VALUES ({$new_day_id}, '{$date}', {$calendar})");
if ($conn->errno === 0) {
return $new_day_id;
} else {
if ($conn->errno === 1062) {
// There's a race condition that can happen if two people start editing
// the same date at the same time, and two IDs are created for the same
// row. If this happens, the UNIQUE constraint `date_calendar` should be
// triggered on the second racer, and for that execution path our last
// query will have failed. We will recover by re-querying for the ID here,
// and deleting the extra ID we created from the `ids` table.
$result = $conn->query("SELECT id FROM days WHERE date = '{$date}' AND calendar = {$calendar}");
$existing_row = $result->fetch_assoc();
$conn->query("DELETE FROM ids WHERE id = {$new_day_id}");
return intval($existing_row['id']);
}
}
return null;
}
<?php
require_once 'config.php';
require_once 'auth.php';
header("Content-Type: application/json");
if ($https && !isset($_SERVER['HTTPS'])) {
// We're using mod_rewrite .htaccess for HTTPS redirect; this shouldn't happen
header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error', true, 500);
exit;
}
if (!isset($_POST['calendar']) || !isset($_POST['subscribe'])) {
exit(json_encode(array('error' => 'invalid_parameters', 'test' => $_POST)));
}
$calendar = (int) $_POST['calendar'];
$subscribe = $_POST['subscribe'] ? 1 : 0;
$can_see = viewer_can_see_calendar($calendar);
if ($can_see === null) {
exit(json_encode(array('error' => 'invalid_parameters')));
}
if (!$can_see) {
exit(json_encode(array('error' => 'invalid_credentials')));
}
$viewer_id = get_viewer_id();
$time = round(microtime(true) * 1000);
// in milliseconds
$conn->query("INSERT INTO roles(calendar, user, " . "creation_time, last_view, role, subscribed) " . "VALUES ({$calendar}, {$viewer_id}, {$time}, {$time}, " . ROLE_VIEWED . ", {$subscribe}) ON DUPLICATE KEY UPDATE " . "creation_time = LEAST(VALUES(creation_time), creation_time), " . "last_view = GREATEST(VALUES(last_view), last_view), " . "role = GREATEST(VALUES(role), role), subscribed = VALUES(subscribed)");
exit(json_encode(array('success' => true)));