let's see..
use the curl_multi api (it's the only sane choice for doing this in PHP)
have a max simultaneous connection limit, don't just create a connection for each url (you'll get out-of-memory or out-of-resource errors if you just create a million simultaneous connections. and i wouldn't even trust the timeout errors if you just created a million connections simultaneously)
only fetch the headers, because downloading the body would be a waste of time and bandwidth
here is my attempt:
// if return_fault_reason is false, then the return is a simple array of strings of urls that validated.
// otherwise it's an array with the url as the key containing array(bool validated,int curl_error_code,string reason) for every url
function validate_urls(array $urls, int $max_connections, int $timeout_ms = 10000, bool $consider_http_300_redirect_as_error = true, bool $return_fault_reason) : array
{
if ($max_connections < 1) {
throw new InvalidArgumentException("max_connections MUST be >=1");
}
foreach ($urls as $key => $foo) {
if (!is_string($foo)) {
throw new \InvalidArgumentException("all urls must be strings!");
}
if (empty($foo)) {
unset($urls[$key]); //?
}
}
unset($foo);
$urls = array_unique($urls); // remove duplicates.
$ret = array();
$mh = curl_multi_init();
$workers = array();
$work = function () use (&$ret, &$workers, &$mh, &$return_fault_reason) {
// > If an added handle fails very quickly, it may never be counted as a running_handle
while (1) {
curl_multi_exec($mh, $still_running);
if ($still_running < count($workers)) {
break;
}
$cms=curl_multi_select($mh, 10);
//var_dump('sr: ' . $still_running . " c: " . count($workers)." cms: ".$cms);
}
while (false !== ($info = curl_multi_info_read($mh))) {
//echo "NOT FALSE!";
//var_dump($info);
{
if ($info['msg'] !== CURLMSG_DONE) {
continue;
}
if ($info['result'] !== CURLM_OK) {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(false, $info['result'], "curl_exec error " . $info['result'] . ": " . curl_strerror($info['result']));
}
} elseif (CURLE_OK !== ($err = curl_errno($info['handle']))) {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(false, $err, "curl error " . $err . ": " . curl_strerror($err));
}
} else {
$code = (string)curl_getinfo($info['handle'], CURLINFO_HTTP_CODE);
if ($code[0] === "3") {
if ($consider_http_300_redirect_as_error) {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(false, -1, "got a http " . $code . " redirect, which is considered an error");
}
} else {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(true, 0, "got a http " . $code . " redirect, which is considered a success");
} else {
$ret[] = $workers[(int)$info['handle']];
}
}
} elseif ($code[0] === "2") {
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(true, 0, "got a http " . $code . " code, which is considered a success");
} else {
$ret[] = $workers[(int)$info['handle']];
}
} else {
// all non-2xx and non-3xx are always considered errors (500 internal server error, 400 client error, 404 not found, etcetc)
if ($return_fault_reason) {
$ret[$workers[(int)$info['handle']]] = array(false, -1, "got a http " . $code . " code, which is considered an error");
}
}
}
curl_multi_remove_handle($mh, $info['handle']);
assert(isset($workers[(int)$info['handle']]));
unset($workers[(int)$info['handle']]);
curl_close($info['handle']);
}
}
//echo "NO MORE INFO!";
};
foreach ($urls as $url) {
while (count($workers) >= $max_connections) {
//echo "TOO MANY WORKERS!\n";
$work();
}
$neww = curl_init($url);
if (!$neww) {
trigger_error("curl_init() failed! probably means that max_connections is too high and you ran out of resources", E_USER_WARNING);
if ($return_fault_reason) {
$ret[$url] = array(false, -1, "curl_init() failed");
}
continue;
}
$workers[(int)$neww] = $url;
curl_setopt_array($neww, array(
CURLOPT_NOBODY => 1,
CURLOPT_SSL_VERIFYHOST => 0,
CURLOPT_SSL_VERIFYPEER => 0,
CURLOPT_TIMEOUT_MS => $timeout_ms
));
curl_multi_add_handle($mh, $neww);
//curl_multi_exec($mh, $unused_here); LIKELY TO BE MUCH SLOWER IF DONE IN THIS LOOP: TOO MANY SYSCALLS
}
while (count($workers) > 0) {
//echo "WAITING FOR WORKERS TO BECOME 0!";
//var_dump(count($workers));
$work();
}
curl_multi_close($mh);
return $ret;
}
here is some test code
$urls = [
'www.example.org',
'www.google.com',
'https://www.google.com',
];
var_dump(validate_urls($urls, 1000, 1, true, false));
returns
array(0) {
}
because they all timed out (1 millisecond timeout), and fail reason reporting was disabled (that's the last argument),
$urls = [
'www.example.org',
'www.google.com',
'https://www.google.com',
];
var_dump(validate_urls($urls, 1000, 1, true, true));
returns
array(3) {
["www.example.org"]=>
array(3) {
[0]=>
bool(false)
[1]=>
int(28)
[2]=>
string(39) "curl_exec error 28: Timeout was reached"
}
["www.google.com"]=>
array(3) {
[0]=>
bool(false)
[1]=>
int(28)
[2]=>
string(39) "curl_exec error 28: Timeout was reached"
}
["https://www.google.com"]=>
array(3) {
[0]=>
bool(false)
[1]=>
int(28)
[2]=>
string(39) "curl_exec error 28: Timeout was reached"
}
}
increasing the timeout limit to 1000 we get
var_dump(validate_urls($urls, 1000, 1000, true, false));
=
array(3) {
[0]=>
string(14) "www.google.com"
[1]=>
string(22) "https://www.google.com"
[2]=>
string(15) "www.example.org"
}
and
var_dump(validate_urls($urls, 1000, 1000, true, true));
=
array(3) {
["www.google.com"]=>
array(3) {
[0]=>
bool(true)
[1]=>
int(0)
[2]=>
string(50) "got a http 200 code, which is considered a success"
}
["www.example.org"]=>
array(3) {
[0]=>
bool(true)
[1]=>
int(0)
[2]=>
string(50) "got a http 200 code, which is considered a success"
}
["https://www.google.com"]=>
array(3) {
[0]=>
bool(true)
[1]=>
int(0)
[2]=>
string(50) "got a http 200 code, which is considered a success"
}
}
and so on :) the speed should depend on your bandwidth and $max_connections variable, which is configurable.
