Implementation:Google deepmind Mujoco User VFS Header

Knowledge Sources	Google_deepmind_Mujoco
Domains	Physics Simulation, Virtual File System
Last Updated	2026-02-15 04:00 GMT

Overview

Declares the VFS (Virtual File System) class that manages resource providers and file operations for MuJoCo.

Description

user_vfs.h defines the mujoco::user::VFS class, which is the underlying implementation for the opaque mjVFS struct. The VFS owns and manages all mjResource instances created via mju_openResource, routing open/read/close operations to the appropriate mjpResourceProvider based on mounted paths. Providers can be mounted explicitly (via mj_mountVFS) or implicitly (via mjp_registerResourceProvider), with a default file-based provider as fallback. The class supports a self-destruct mode for legacy cases where VFS is an optional argument. It provides status codes for operations and is thread-safe through mutex protection.

Usage

Included by resource management code to declare the VFS interface, which is used whenever MuJoCo needs to open, read, or close external file resources.

Code Reference

Source Location

• Repository: Google_deepmind_Mujoco
• File: src/user/user_vfs.h
• Lines: 1-131

Key Functions

namespace mujoco::user {
class VFS {
 public:
  explicit VFS(mjVFS* vfs);
  ~VFS();

  mjResource* Open(const char* dir, const char* name);
  int Read(mjResource* resource, const void** buffer);
  // Close, Mount, SetToSelfDestruct, Upcast, etc.

  enum Status {
    kSuccess = 0,
    kFailedToLoad = -1,
    kRepeatedName = 2,
    // ...
  };
};
}  // namespace mujoco::user

Import

#include "user/user_vfs.h"

I/O Contract

Inputs

Name	Type	Required	Description
vfs	mjVFS*	Yes	Opaque VFS struct to wrap
dir	const char*	No	Base directory for resource path resolution
name	const char*	Yes	Resource name to open

Outputs

Name	Type	Description
mjResource*	mjResource*	Opened resource handle, or nullptr on error
int	int	Bytes read from resource, or -1 on error
Status	enum	Operation result code

Related Pages

• Environment:Google_deepmind_Mujoco_C_Build_Environment