Repository Structure

Relevant source files

• .gitignore
• Cargo.toml
• README.md

This page provides an overview of the organization of the axfs_crates repository, including its workspace setup, available crates, and the relationships between these components. For information about the overall filesystem architecture, see File System Architecture.

Workspace Organization

The axfs_crates repository is structured as a Rust workspace containing three primary crates, each implementing a distinct aspect of the filesystem infrastructure:

flowchart TD
A["axfs_crates Workspace"]
B["axfs_vfs: Virtual File System Interface"]
C["Implements VFS interface"]
D["Implements VFS interface"]

A --> B
A --> C
A --> D
B --> C
B --> D

Title: Repository Workspace Structure

Sources: Cargo.toml(L1 - L8)  README.md(L5 - L9) 

The workspace configuration is defined in the root Cargo.toml file, which specifies the member crates and shared metadata, including version information, author details, and licensing.

Crate Overview

The repository consists of the following crates:

Sources: README.md(L5 - L9)  Cargo.toml(L4 - L8) 

Dependency Relationships

The crates follow a clear hierarchical relationship, with axfs_vfs serving as the foundation that other filesystems build upon:

flowchart TD
subgraph subGraph1["External Usage"]
    app["Application Code"]
end
subgraph subGraph0["Crate Dependencies"]
    vfs["axfs_vfs: VfsNodeOps, VfsOps traits"]
    devfs["axfs_devfs: DeviceFileSystem"]
    ramfs["axfs_ramfs: RAMFileSystem"]
end

app --> devfs
app --> ramfs
app --> vfs
devfs --> vfs
ramfs --> vfs

Title: Dependency Structure Between Crates

Sources: Cargo.toml(L19 - L20) 

Key aspects of this dependency structure:

• axfs_vfs has no dependencies on other filesystem crates in the workspace
• Both axfs_devfs and axfs_ramfs depend on axfs_vfs to implement its interfaces
• Application code can use any or all of these crates, typically interacting through the axfs_vfs abstractions

Internal Structure of the Crates

axfs_vfs

The Virtual File System (VFS) crate defines the core interfaces that filesystem implementations must adhere to:

classDiagram
class VfsNodeOps {
    <<trait>>
    
    +get_attr() VfsResult~VfsNodeAttr~
    +parent() Option~VfsNodeRef~
    +lookup(path: str) VfsResult~VfsNodeRef~
    +read_dir(start_idx: usize, dirents: [VfsDirEntry]) VfsResult~usize~
    +read_at(offset: u64, buf: &mut [u8]) VfsResult~usize~
    +write_at(offset: u64, buf: &[u8]) VfsResult~usize~
    +create(path: str, ty: VfsNodeType) VfsResult
    +remove(path: str) VfsResult
    +truncate(size: u64) VfsResult
}

class VfsOps {
    <<trait>>
    
    +mount(path: str, mount_point: VfsNodeRef) VfsResult
    +root_dir() VfsNodeRef
}

class VfsNodeType {
    <<enum>>
    File
    Dir
    SymLink
    CharDevice
    BlockDevice
    Socket
    NamedPipe
    
}

Title: Core Traits in axfs_vfs

Sources: Based on the system architecture diagrams

axfs_devfs

The Device Filesystem provides a hierarchical structure for accessing system devices:

classDiagram
class DeviceFileSystem {
    -parent: Once~VfsNodeRef~
    -root: Arc~DirNode~
    +new() DeviceFileSystem
    +mkdir(name: str) Arc~DirNode~
    +add(name: str, node: VfsNodeRef) void
}

class DirNode {
    -parent: RwLock~Weak~dyn VfsNodeOps~~
    -children: RwLock~BTreeMap~str, VfsNodeRef~~
    +new(parent: Option~&VfsNodeRef~) Arc
    +mkdir(name: str) Arc
    +add(name: str, node: VfsNodeRef)
}

class NullDev {
    implements VfsNodeOps
    
}

class ZeroDev {
    implements VfsNodeOps
    
}

DeviceFileSystem  -->  DirNode : "contains root"
DirNode  -->  NullDev : "can contain"
DirNode  -->  ZeroDev : "can contain"

Title: DeviceFileSystem Implementation Structure

Sources: Based on the system architecture diagrams

axfs_ramfs

The RAM Filesystem provides an in-memory implementation of the filesystem interface:

classDiagram
class RAMFileSystem {
    implements VfsOps
    -root: Arc~DirNode~
    +new() RAMFileSystem
    +root_dir() VfsNodeRef
}

class DirNode {
    implements VfsNodeOps
    
}

class FileNode {
    implements VfsNodeOps
    -content: RwLock~Vec~u8~~
    
}

RAMFileSystem  -->  DirNode : "contains root"
DirNode  -->  DirNode
DirNode  -->  DirNode : "can contain subdirectories"
DirNode  -->  DirNode
DirNode  -->  FileNode : "can contain files"

Title: RAMFileSystem Implementation Structure

Sources: Based on the system architecture diagrams

Repository Configuration

The repository follows standard Rust project conventions and includes the following key configuration files:

Sources: Cargo.toml(L1 - L21)  .gitignore(L1 - L4)  README.md(L1 - L10) 

Publishing Information

The crates in this repository are published on crates.io and have the following shared metadata:

Sources: Cargo.toml(L10 - L17) 

This repository structure enables the development of modular filesystem components that can be used independently or together to provide filesystem functionality for the ArceOS operating system or other embedded systems projects.