(PECL mongo >=1.3.0) Returns a resource that can be used to read the stored file
(PECL mongo >=0.9.0) Returns this file's size
(PECL mongo >=0.9.0) Writes this file to the filesystem
(PECL mongo >=0.9.0) Returns this file's contents as a string of bytes
(PECL mongo >=0.9.0) Returns this file's filename
(PECL mongo >=0.9.0) Create a new GridFS file