Struct TarFileSystem 

pub struct TarFileSystem { /* private fields */ }

Read-only filesystem backed by the mount chunk of a .aospkg package.

The package container is header + manifest + mount index + mount.tar. TarFileSystem::open decodes only the precomputed mount index and serves reads from the uncompressed mount.tar chunk at mountBase + offset. Extraction would create a duplicate host tree, thousands of physical inodes, and a cleanup problem before reading the same bytes again.

File reads are an O(log n) index lookup plus a page-cache-backed memory slice; metadata and directory listings come from the in-memory index. The index must be pre-sorted by canonical path, and load performs a release-safe adjacent-order check before any binary-search-dependent path can run. The mmap is keyed by file identity and shared across VMs, so RSS follows the pages actually touched rather than the full archive size. This open path is on VM startup (configure_vm), so it must stay O(index decode): never parse tar headers, read/hash the whole archive, or recover metadata from legacy in-archive JSON here.

This filesystem is mounted only as a granular package-version leaf such as /opt/agentos/pkgs/<pkg>/<version>. Managed commands and current aliases are separate symlink leaf mounts, while parent directories stay writable overlay directories so user-installed files can coexist with managed ones.

Implementations

impl TarFileSystem

pub fn open(path: impl AsRef<Path>) -> Result<TarFileSystem, VfsError>

pub fn open_at( path: impl AsRef<Path>, root: &str, ) -> Result<TarFileSystem, VfsError>

pub fn source_path(&self) -> &Path

pub fn archive_root(&self) -> &str

Trait Implementations

impl Clone for TarFileSystem

fn clone(&self) -> TarFileSystem

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl VirtualFileSystem for TarFileSystem

fn read_file(&mut self, path: &str) -> Result<Vec<u8>, VfsError>

fn read_dir(&mut self, path: &str) -> Result<Vec<String>, VfsError>

fn read_dir_with_types( &mut self, path: &str, ) -> Result<Vec<VirtualDirEntry>, VfsError>

fn write_file( &mut self, path: &str, _content: impl Into<Vec<u8>>, ) -> Result<(), VfsError>

Writes caller-owned bytes into the filesystem.

fn create_dir(&mut self, path: &str) -> Result<(), VfsError>

fn mkdir(&mut self, path: &str, _recursive: bool) -> Result<(), VfsError>

fn exists(&self, path: &str) -> bool

fn stat(&mut self, path: &str) -> Result<VirtualStat, VfsError>

fn remove_file(&mut self, path: &str) -> Result<(), VfsError>

fn remove_dir(&mut self, path: &str) -> Result<(), VfsError>

fn rename(&mut self, old_path: &str, new_path: &str) -> Result<(), VfsError>

fn realpath(&self, path: &str) -> Result<String, VfsError>

fn symlink(&mut self, target: &str, link_path: &str) -> Result<(), VfsError>

fn read_link(&self, path: &str) -> Result<String, VfsError>

fn lstat(&self, path: &str) -> Result<VirtualStat, VfsError>

fn link(&mut self, old_path: &str, new_path: &str) -> Result<(), VfsError>

fn chmod(&mut self, path: &str, _mode: u32) -> Result<(), VfsError>

fn chown(&mut self, path: &str, _uid: u32, _gid: u32) -> Result<(), VfsError>

fn utimes( &mut self, path: &str, _atime_ms: u64, _mtime_ms: u64, ) -> Result<(), VfsError>

fn utimes_spec( &mut self, path: &str, _atime: VirtualUtimeSpec, _mtime: VirtualUtimeSpec, _follow_symlinks: bool, ) -> Result<(), VfsError>

fn truncate(&mut self, path: &str, _length: u64) -> Result<(), VfsError>

Resizes a file. VM resource policy must be enforced by the caller.

fn pread( &mut self, path: &str, offset: u64, length: usize, ) -> Result<Vec<u8>, VfsError>

fn read_text_file(&mut self, path: &str) -> Result<String, VfsError>

fn read_dir_limited( &mut self, path: &str, max_entries: usize, ) -> Result<Vec<String>, VfsError>

fn write_file_with_mode( &mut self, path: &str, content: impl Into<Vec<u8>>, mode: Option<u32>, ) -> Result<(), VfsError>

fn create_file_exclusive( &mut self, path: &str, content: impl Into<Vec<u8>>, ) -> Result<(), VfsError>

fn create_file_exclusive_with_mode( &mut self, path: &str, content: impl Into<Vec<u8>>, mode: Option<u32>, ) -> Result<(), VfsError>

fn append_file( &mut self, path: &str, content: impl Into<Vec<u8>>, ) -> Result<u64, VfsError>

Appends caller-owned bytes into the filesystem after checking that the in-memory file can grow without overflowing addressable memory.

fn create_dir_with_mode( &mut self, path: &str, mode: Option<u32>, ) -> Result<(), VfsError>

fn mkdir_with_mode( &mut self, path: &str, recursive: bool, mode: Option<u32>, ) -> Result<(), VfsError>

fn pwrite( &mut self, path: &str, content: impl Into<Vec<u8>>, offset: u64, ) -> Result<(), VfsError>

Writes caller-owned bytes at an offset after checking that the in-memory file can grow without overflowing addressable memory.