/**
* Perform a HEAD request to the specified URL.
*
* Note :
*
* Since the MediaFire checker works by parsing the "Location" header, redirect following
* _must_ be disabled. This can become a problem on servers where WP is forced to fall back
* on using WP_Http_Fopen which ignores the 'redirection' flag. WP_Http_Fsockopen would work,
* but it has the lowest priority of all transports.
*
* Alas, there is no way to reliably influence which transport is chosen - the WP_Http::_getTransport
* function caches the available choices, so plugins can disable individual transports only during
* its first run. Therefore, we must pick the best transport manually.
*
* @param string $url
* @return array|WP_Error
*/
function head($url)
{
//Only consider transports that allow redirection to be disabled.
$args = array();
if (class_exists('WP_Http_ExtHttp') && true === WP_Http_ExtHttp::test($args)) {
$transport = new WP_Http_ExtHttp();
} else {
if (class_exists('WP_Http_Curl') && true === WP_Http_Curl::test($args)) {
$transport = new WP_Http_Curl();
} else {
if (class_exists('WP_Http_Curl') && true === WP_Http_Fsockopen::test($args)) {
$transport = new WP_Http_Fsockopen();
} else {
return new WP_Error('no_suitable_transport', "No suitable HTTP transport found. Please upgrade to a more recent version of PHP or install the CURL extension.");
}
}
}
$conf = blc_get_configuration();
$args = array('timeout' => $conf->options['timeout'], 'redirection' => 0, 'method' => 'HEAD');
return $transport->request($url, $args);
}
/**
* Tests the WordPress HTTP objects for an object to use and returns it.
*
* Tests all of the objects and returns the object that passes. Also caches
* that object to be used later. This is for posting content to a URL and
* is used when there is a body. The plain Fopen Transport can not be used
* to send content, but the streams transport can. This is a limitation that
* is addressed here, by just not including that transport.
*
* @since 2.7.0
* @access private
*
* @param array $args Request args, default us an empty array
* @return object|null Null if no transports are available, HTTP transport object.
*/
function &_postTransport($args = array())
{
static $working_transport, $blocking_transport, $nonblocking_transport;
if (is_null($working_transport)) {
if (true === WP_Http_ExtHttp::test($args)) {
$working_transport['exthttp'] = new WP_Http_ExtHttp();
$blocking_transport[] =& $working_transport['exthttp'];
} else {
if (true === WP_Http_Curl::test($args)) {
$working_transport['curl'] = new WP_Http_Curl();
$blocking_transport[] =& $working_transport['curl'];
} else {
if (true === WP_Http_Streams::test($args)) {
$working_transport['streams'] = new WP_Http_Streams();
$blocking_transport[] =& $working_transport['streams'];
} else {
if (true === WP_Http_Fsockopen::test($args)) {
$working_transport['fsockopen'] = new WP_Http_Fsockopen();
$blocking_transport[] =& $working_transport['fsockopen'];
}
}
}
}
foreach (array('curl', 'streams', 'fsockopen', 'exthttp') as $transport) {
if (isset($working_transport[$transport])) {
$nonblocking_transport[] =& $working_transport[$transport];
}
}
}
do_action('http_transport_post_debug', $working_transport, $blocking_transport, $nonblocking_transport);
if (isset($args['blocking']) && !$args['blocking']) {
return $nonblocking_transport;
} else {
return $blocking_transport;
}
}
/**
* Tests the WordPress HTTP objects for an object to use and returns it.
*
* Tests all of the objects and returns the object that passes. Also caches
* that object to be used later. This is for posting content to a URL and
* is used when there is a body. The plain Fopen Transport can not be used
* to send content, but the streams transport can. This is a limitation that
* is addressed here, by just not including that transport.
*
* @since 2.7.0
* @access private
*
* @param array $args Request args, default us an empty array
* @return object|null Null if no transports are available, HTTP transport object.
*/
function &_postTransport($args = array())
{
static $working_transport, $blocking_transport, $nonblocking_transport;
if (is_null($working_transport)) {
if (true === WP_Http_ExtHttp::test() && apply_filters('use_http_extension_transport', true)) {
$working_transport['exthttp'] = new WP_Http_ExtHttp();
$blocking_transport[] =& $working_transport['exthttp'];
} else {
if (true === WP_Http_Streams::test() && apply_filters('use_streams_transport', true)) {
$working_transport['streams'] = new WP_Http_Streams();
$blocking_transport[] =& $working_transport['streams'];
} else {
if (true === WP_Http_Fsockopen::test() && apply_filters('use_fsockopen_transport', true)) {
$working_transport['fsockopen'] = new WP_Http_Fsockopen();
$blocking_transport[] =& $working_transport['fsockopen'];
}
}
}
foreach (array('streams', 'fsockopen', 'exthttp') as $transport) {
if (isset($working_transport[$transport])) {
$nonblocking_transport[] =& $working_transport[$transport];
}
}
}
if (has_filter('http_transport_post_debug')) {
do_action('http_transport_post_debug', $working_transport, $blocking_transport, $nonblocking_transport);
}
if (isset($args['blocking']) && !$args['blocking']) {
return $nonblocking_transport;
} else {
return $blocking_transport;
}
}