PHP已知图片base64流上传到服务器

<?php
   $img=$_POST['basefile'];
   $data=saveBase64Image($img);
   var_dump($data);


/**
 * 保存64位编码图片
 */

function saveBase64Image($base64_image_content){

  if (preg_match('/^(data:\s*image\/(\w+);base64,)/', $base64_image_content, $result)){

            //图片后缀
            $type = $result[2];
            if($type=='jpeg'){
                  $type='jpg';
            }

            //保存位置--图片名
            $image_name=date('His').str_pad(mt_rand(1, 99999), 5, '0', STR_PAD_LEFT).".".$type;
            $image_url = 'upload/'.date('Ymd').'/'.$image_name;           
            if(!is_dir(dirname('./'.$image_url))){
                   mkdir(dirname('./'.$image_url));
                   chmod(dirname('./'.$image_url), 0777);
                  // umask($oldumask);

            }
           
            //解码
            $decode=base64_decode(str_replace($result[1], '', $base64_image_content));
            if (file_put_contents('./'.$image_url, $decode)){
                  $data['code']='0';
                  $data['imageName']=$image_name;
                  $data['image_url']=$image_url;
                  $data['type']=$type;
                  $data['msg']='保存成功！';
            }else{
              $data['code']='1';
              $data['imgageName']='';
              $data['image_url']='';
              $data['type']='';
              $data['msg']='图片保存失败！';
            }
  }else{
      $data['code']='1';
      $data['imgageName']='';
      $data['image_url']='';
      $data['type']='';
      $data['msg']='base64图片格式有误！';


  }       
  return $data;


}