<?php # vim:ts=2:sw=2:et:
/* For licensing and copyright terms, see the file named LICENSE */

require_once 'MTrackWeb.php';

class MTrackWeb_Avatar extends MTrackWeb
{
    var $cache_duration = 3600;
    function getAuth()
    {
        return parent::getAuth();
    }
    
    function get() 
    {
        if (empty($_GET['u']) || empty($_GET['s'])) {
            die("invalid url");
        }
      
        $size = $_GET['s'];
        $u = DB_DataObject::factory('userinfo');
        $u->get('userid', $_GET['u']);
        
        $this->cachedir = ini_get('session.save_path').'/mtrack_cache';
        if (!file_exists($this->cachedir)) {
            mkdir($this->cachedir, 0700,true);
        }
        
        if (empty($u->avatar) && !empty($u->email))
        {
            $u->avatar  ="http://www.gravatar.com/avatar/" .
                md5(strtolower($u->email)) . "?s=$size&d=wavatar";
        }
        
                
        if ($u->avatar ) {
          $hint = basename($u->avatar );
          list($tosend) = $this->cache_get_url_and_operate(  $u->avatar);
          
          if ($tosend) {
            header("Content-Type: image/png");
            header("Content-Disposition: inline; filename=\"$hint\"");
            echo $tosend;
            exit;
          }
        }

        $cache = dirname(__FILE__) . "/images/default_avatar.png";
        header('Content-Type:image/png');
        header("Content-Disposition: inline");
        readfile($cache);
        exit;
        }
    // removed favatar option....

        /**
         * Fetches the contents of the URL $source using a cache.
         * Optionally runs a callback specified by $funcname on the
         * data while it is under a lock (to ensure a consistent view).
         * $funcname is passed the local cache filename as its first parameter.
         * Any additional parameters passed to this function will be passed
         * to $funcname as parameters after the cache filename.
         *
         * returns an array(
         *  0 => data from the url
         *  1 => return value of optional funcname
         * )
         */
    function cache_get_url_and_operate($source, $funcname = null /* args */)
    {
            

          $args = func_get_args();
          if (count($args) > 2) {
            array_shift($args);
            array_shift($args);
          } else {
            $args = array();
          }
          $cache = $this->cachedir . "/" . md5($source);
          array_unshift($args, $cache);

          // cache file population, avoiding thundering herd and maintaining
          // consistency under concurrency.

          $dat = null;
          $tosend = null;

          $tries = 20;
          while ($tries-- > 0) {
            //logit("tries=$tries");
            // Can we open the file for read?
            $fp = @fopen($cache, 'r+b');
            if (!$fp) {
              $fp = @fopen($cache, 'x+');
            }
            if ($fp) {
              // Yes; get a lock for consistency
              flock($fp, LOCK_SH);
             // logit("got shared lock");
              // What do we need to do?
              $st = fstat($fp);
              if ($st['size'] == 0) {
                // No data in the file, let's see if we can do something about that
                //logit("zero size; getting ex lock");
                flock($fp, LOCK_EX);
                $st = fstat($fp);
                if ($st['size'] == 0) {
                  // We get to fix it
                  //logit("zero sized; we're fixing it, reading from $source");
                  $tosend = file_get_contents($source);
                  fwrite($fp, $tosend);

                  //if ($funcname !== null) {
                  //  $dat = call_user_func_array($funcname, $args);
                  //}
                  break;
                }
                // Someone else fixed it
                //logit("Someone else fixed it, size is now $st[size]");
              } else if (time() - $st['mtime'] > $this->cache_duration) {
                // Someone needs to re-fetch the data
                //logit("Past cache period, getting ex lock");
                flock($fp, LOCK_EX);
                $st = fstat($fp);
                if (time() - $st['mtime'] > $this->cache_duration) {
                  // We get to fix it
                  //logit("cache expired; reading from $source, truncating");
                  ftruncate($fp, 0);
                  rewind($fp);
                  $tosend = file_get_contents($source);
                  //logit("read " . strlen($tosend) . " from $source");
                  $x = fwrite($fp, $tosend);
                  //logit("wrote $x to local cache file");
                  //if ($funcname !== null) {
                  //  $dat = call_user_func_array($funcname, $args);
                  //}
                  break;
                }
                // Someone else fixed it
                //logit("Someone fixed it, mtime now $st[mtime]");
              }
              // Good to read through
              //logit("Reading through cache");
              $tosend = stream_get_contents($fp);
              //if ($funcname !== null) {
              //  $dat = call_user_func_array($funcname, $args);
              //}
              break;
            }
            //logit("Couldn't get data, sleeping and retrying");
            usleep(100);
          }
          if ($fp) {
            flock($fp, LOCK_UN);
            fclose($fp);
          }
          return array($tosend, $dat);
        }

        }