/**
 * Default filter attached to pingback_ping_source_uri to validate the pingback's Source URI
 *
 * @since 3.5.1
 * @see wp_http_validate_url()
 *
 * @param string $source_uri
 * @return string
 */
function pingback_ping_source_uri($source_uri)
{
    return (string) wp_http_validate_url($source_uri);
}

//.........这里部分代码省略.........
      *
      * @param array  $r   An array of HTTP request arguments.
      * @param string $url The request URL.
      */
     $r = apply_filters('http_request_args', $r, $url);
     // The transports decrement this, store a copy of the original value for loop purposes.
     if (!isset($r['_redirection'])) {
         $r['_redirection'] = $r['redirection'];
     }
     /**
      * Filter whether to preempt an HTTP request's return value.
      *
      * Returning a non-false value from the filter will short-circuit the HTTP request and return
      * early with that value. A filter should return either:
      *
      *  - An array containing 'headers', 'body', 'response', 'cookies', and 'filename' elements
      *  - A WP_Error instance
      *  - boolean false (to avoid short-circuiting the response)
      *
      * Returning any other value may result in unexpected behaviour.
      *
      * @since 2.9.0
      *
      * @param false|array|WP_Error $preempt Whether to preempt an HTTP request's return value. Default false.
      * @param array               $r        HTTP request arguments.
      * @param string              $url      The request URL.
      */
     $pre = apply_filters('pre_http_request', false, $r, $url);
     if (false !== $pre) {
         return $pre;
     }
     if (function_exists('wp_kses_bad_protocol')) {
         if ($r['reject_unsafe_urls']) {
             $url = wp_http_validate_url($url);
         }
         if ($url) {
             $url = wp_kses_bad_protocol($url, array('http', 'https', 'ssl'));
         }
     }
     $arrURL = @parse_url($url);
     if (empty($url) || empty($arrURL['scheme'])) {
         return new WP_Error('http_request_failed', __('A valid URL was not provided.'));
     }
     if ($this->block_request($url)) {
         return new WP_Error('http_request_failed', __('User has blocked requests through HTTP.'));
     }
     /*
      * Determine if this is a https call and pass that on to the transport functions
      * so that we can blacklist the transports that do not support ssl verification
      */
     $r['ssl'] = $arrURL['scheme'] == 'https' || $arrURL['scheme'] == 'ssl';
     // Determine if this request is to OUR install of WordPress.
     $homeURL = parse_url(get_bloginfo('url'));
     $r['local'] = 'localhost' == $arrURL['host'] || isset($homeURL['host']) && $homeURL['host'] == $arrURL['host'];
     unset($homeURL);
     /*
      * If we are streaming to a file but no filename was given drop it in the WP temp dir
      * and pick its name using the basename of the $url.
      */
     if ($r['stream'] && empty($r['filename'])) {
         $r['filename'] = get_temp_dir() . wp_unique_filename(get_temp_dir(), basename($url));
     }
     /*
      * Force some settings if we are streaming to a file and check for existence and perms
      * of destination directory.
      */

//.........这里部分代码省略.........
      *
      * @param array  $r   An array of HTTP request arguments.
      * @param string $url The request URL.
      */
     $r = apply_filters('http_request_args', $r, $url);
     // The transports decrement this, store a copy of the original value for loop purposes.
     if (!isset($r['_redirection'])) {
         $r['_redirection'] = $r['redirection'];
     }
     /**
      * Filters whether to preempt an HTTP request's return value.
      *
      * Returning a non-false value from the filter will short-circuit the HTTP request and return
      * early with that value. A filter should return either:
      *
      *  - An array containing 'headers', 'body', 'response', 'cookies', and 'filename' elements
      *  - A WP_Error instance
      *  - boolean false (to avoid short-circuiting the response)
      *
      * Returning any other value may result in unexpected behaviour.
      *
      * @since 2.9.0
      *
      * @param false|array|WP_Error $preempt Whether to preempt an HTTP request's return value. Default false.
      * @param array               $r        HTTP request arguments.
      * @param string              $url      The request URL.
      */
     $pre = apply_filters('pre_http_request', false, $r, $url);
     if (false !== $pre) {
         return $pre;
     }
     if (function_exists('wp_kses_bad_protocol')) {
         if ($r['reject_unsafe_urls']) {
             $url = wp_http_validate_url($url);
         }
         if ($url) {
             $url = wp_kses_bad_protocol($url, array('http', 'https', 'ssl'));
         }
     }
     $arrURL = @parse_url($url);
     if (empty($url) || empty($arrURL['scheme'])) {
         return new WP_Error('http_request_failed', __('A valid URL was not provided.'));
     }
     if ($this->block_request($url)) {
         return new WP_Error('http_request_failed', __('User has blocked requests through HTTP.'));
     }
     // If we are streaming to a file but no filename was given drop it in the WP temp dir
     // and pick its name using the basename of the $url
     if ($r['stream']) {
         if (empty($r['filename'])) {
             $r['filename'] = get_temp_dir() . basename($url);
         }
         // Force some settings if we are streaming to a file and check for existence and perms of destination directory
         $r['blocking'] = true;
         if (!wp_is_writable(dirname($r['filename']))) {
             return new WP_Error('http_request_failed', __('Destination directory for file streaming does not exist or is not writable.'));
         }
     }
     if (is_null($r['headers'])) {
         $r['headers'] = array();
     }
     // WP allows passing in headers as a string, weirdly.
     if (!is_array($r['headers'])) {
         $processedHeaders = WP_Http::processHeaders($r['headers']);
         $r['headers'] = $processedHeaders['headers'];
     }

 /**
  * Handle redirecting the user after authorization
  *
  * @param string $verifier Verification code
  * @return null|WP_Error Null on success, error otherwise
  */
 public function handle_callback_redirect($verifier)
 {
     if (!empty($this->token['callback']) && $this->token['callback'] === 'oob') {
         return apply_filters('json_oauth1_handle_callback', null, $this->token);
     }
     if (empty($this->token['callback'])) {
         // No callback registered, display verification code to the user
         login_header(__('Access Token'));
         echo '<p>' . sprintf(__('Your verification token is <code>%s</code>'), $verifier) . '</p>';
         login_footer();
         return null;
     }
     $callback = $this->token['callback'];
     // Ensure the URL is safe to access
     // wp_http_validate_url is overly restrictive for desktop applications which might use
     // 127.0.0.1:xx for the callback. Add hook that allows localhost and check scheme/host of URL.
     $filtered_callback = parse_url($callback);
     $filtered_callback = $filtered_callback['scheme'] . '://' . $filtered_callback['host'];
     add_filter('http_request_host_is_external', array('WP_JSON_Authentication_OAuth1_Authorize', 'http_request_allow_external'));
     $filtered_callback = wp_http_validate_url($filtered_callback);
     remove_filter('http_request_host_is_external', array('WP_JSON_Authentication_OAuth1_Authorize', 'http_request_allow_external'));
     if (empty($filtered_callback)) {
         return new WP_Error('json_oauth1_invalid_callback', __('The callback URL is invalid'), array('status' => 400));
     }
     $args = array('oauth_token' => $this->token['key'], 'oauth_verifier' => $verifier, 'wp_scope' => '*');
     $args = apply_filters('json_oauth1_callback_args', $args, $token);
     $args = urlencode_deep($args);
     $callback = add_query_arg($args, $callback);
     wp_redirect($callback);
     return null;
 }

 /**
  * Handle redirecting the user after authorization
  *
  * @param string $verifier Verification code
  * @return null|WP_Error Null on success, error otherwise
  */
 public function handle_callback_redirect($verifier)
 {
     if (!empty($this->token['callback']) && $this->token['callback'] === 'oob') {
         return apply_filters('json_oauth1_handle_callback', null, $this->token);
     }
     if (empty($this->token['callback'])) {
         // No callback registered, display verification code to the user
         login_header(__('Access Token'));
         echo '<p>' . sprintf(__('Your verification token is <code>%s</code>'), $verifier) . '</p>';
         login_footer();
         return null;
     }
     $callback = $this->token['callback'];
     // Ensure the URL is safe to access
     $callback = wp_http_validate_url($callback);
     if (empty($callback)) {
         return new WP_Error('json_oauth1_invalid_callback', __('The callback URL is invalid'), array('status' => 400));
     }
     $args = array('oauth_token' => $this->token['key'], 'oauth_verifier' => $verifier, 'wp_scope' => '*');
     $args = apply_filters('json_oauth1_callback_args', $args, $this->token);
     $args = urlencode_deep($args);
     $callback = add_query_arg($args, $callback);
     wp_redirect($callback);
     return null;
 }

 public function image_exist()
 {
     if (false == $this->image() || empty($this->img_src)) {
         return false;
     }
     $result = array();
     if (false == $this->is_local_attachment()) {
         if (false == wp_http_validate_url($this->img_src)) {
             return false;
         }
         $result['external'] = $this->img_src;
         return $result;
     }
     $this->img_src = preg_replace('/-\\d+x\\d+(?=\\.(jpg|jpeg|png|gif)$)/i', '', $this->img_src);
     $img_filename = str_replace($this->upurl . '/', '', $this->img_src);
     $img_path = $this->updir . '/' . $img_filename;
     if (file_exists($img_path) && false != getimagesize($img_path)) {
         if (5 > getimagesize($img_path)[0] || 5 > getimagesize($img_path)[1]) {
             $result['toosmall'] = array('filename' => $img_filename, 'path' => $img_path);
         } else {
             $result['exists'] = array('filename' => $img_filename, 'path' => $img_path, 'src' => $this->img_src);
         }
     } else {
         $result['noexists'] = array('src' => $this->img_src);
     }
     return $result;
 }

 /**
  * PURGE a single URL
  *
  * @param string $url The specific URL to purge the cache for
  *
  * @return bool True on success
  */
 public function queue_purge_url($url)
 {
     $url = esc_url_raw($url);
     $url = wp_http_validate_url($url);
     if (false === $url) {
         return false;
     }
     $this->purge_urls[] = $url;
     return true;
 }