Struct Vfs 

pub struct Vfs { /* private fields */ }

Implementations

impl Vfs

pub fn none() -> Self

A VFS that backs no directory. Every submilli:fs.* call traps; only fs.info() works (reporting mode: none).

pub fn external_with_mode(root: PathBuf, mode: VfsMode) -> Result<Self>

Mount an existing host directory the interpreter does not own. Used for named roots and for per_session dirs owned by the server.

pub fn external(root: PathBuf) -> Result<Self>

An existing host directory, as submilli run --vfs exposes it.

pub fn tempdir() -> Result<Self>

pub fn tempdir_in(parent: &Path) -> Result<Self>

Like tempdir but allocated under parent (created if absent). Lets the host place ephemeral scratch on a chosen volume.

pub fn root(&self) -> &Path

The host path backing this VFS. Server-side logging and test setup only — it is never the thing a guest path is resolved against. Empty for VfsMode::None.

pub fn dir(&self) -> Option<&Arc<Dir>>

The capability handle guest paths resolve against, or None under VfsMode::None.

A handle outlives the directory it was opened on: after the root is deleted the handle still answers is_dir(), so it is not a liveness check.

pub fn mode(&self) -> VfsMode

pub fn with_size_limit(self, limit: u64) -> Self

Enforce limit bytes on the files this VFS holds, starting from what the directory holds now; see with_measured_limit.

pub fn with_measured_limit(self, limit: u64, used: Option<u64>) -> Self

Enforce limit bytes, starting from used, what a walk of the directory found. A directory already over the limit still opens: reads and removals work, and writes that grow it are refused until it is back under. One that couldn’t be measured (None) opens the same way, as if full, so a program can still remove files and let a later run measure it.

pub fn with_shared_quota(self, quota: Arc<DiskQuota>) -> Self

Charge the root to quota, a limit the server shares between every VFS that opens the same named volume.

pub fn quota(&self) -> Option<&Arc<DiskQuota>>

The root’s size limit and its running count, when one applies.

pub fn with_access(self, access: Access) -> Self

Whether guest code may change the root. Mounts carry their own access.

pub fn access(&self) -> Access

pub fn with_volume_name(self, volume: &str) -> Self

Record the named volume backing the root, for fs.info().

pub fn volume(&self) -> Option<&str>

pub fn mounts(&self) -> &[Mount]

pub fn with_mount(self, spec: MountSpec) -> Result<Self, MountError>

Graft the volume spec describes at its guest path.

In a writable root the mount point is created as an empty directory, so listing its parent shows it like any other directory. A read-only root is never written, so there the mount point must already exist.

pub fn with_mount_subpath( self, spec: MountSpec, sub_path: Option<&str>, ) -> Result<Self, MountError>

pub fn with_mount_quota(self, guest_path: &str, quota: Arc<DiskQuota>) -> Self

Charge the volume mounted at guest_path to quota, the limit the server shares between every VFS that mounts it. No mount there is a no-op.

pub fn locate(&self, rel: &Path) -> Option<(Arc<Dir>, PathBuf, Placement)>

Route a root-relative path (as the lexical pass produced it) to the volume that holds it: the handle to open it through, the path relative to that handle, and the volume’s placement. None under VfsMode::None.

Matching is by whole components, so /memoryx is not under /memory. A mount point itself resolves to its volume’s root, ..

pub fn cwd(&self) -> &str

Guest working directory shared by I/O, policy, and introspection.

pub fn with_cwd(self, cwd: &str) -> Result<Self, ContainError>

pub fn with_subpath(self, sub_path: Option<&str>) -> Result<Self>

Select a directory through the volume handle, without ambient reopening.

pub fn measure_usage(&self) -> Result<u64>

The bytes held by regular files under the root; see measure_dir.

Trait Implementations

impl Clone for Vfs

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Vfs

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.