Struct InMemoryFs 

pub struct InMemoryFs { /* private fields */ }

In-memory Vfs backing. Useful for tests, dry-run previews, and sandboxed environments where the apply layer must not touch the host filesystem.

Cheap to clone — all clones share the same underlying storage, so a caller can hand a clone to ApplyConfig::with_vfs and then inspect the in-memory state after the apply returns via the retained clone.

Storage shape

• Files: BTreeMap<PathBuf, Vec<u8>>, keyed by the absolute path the apply layer resolved them to.
• Directories: BTreeSet<PathBuf> of created directories.
• Both maps live behind a single Arc<Mutex<_>>. Contention is not a concern — the apply layer is single-threaded and holds the lock only for the duration of one syscall-shaped operation.

Implementations

impl InMemoryFs

pub fn new() -> Self

Construct an empty in-memory filesystem.

pub fn snapshot_files(&self) -> BTreeMap<PathBuf, Vec<u8>>

Take a snapshot of every file’s contents.

The returned map is keyed by the absolute path the apply layer wrote to. Use this after a successful apply to inspect the resulting layout in tests.

Panics

Panics if the internal mutex is poisoned.

pub fn snapshot_dirs(&self) -> BTreeSet<PathBuf>

Take a snapshot of every created directory path.

Panics

Panics if the internal mutex is poisoned.

pub fn read_file(&self, path: &Path) -> Option<Vec<u8>>

Read the bytes of a single file. Returns None if absent.

Panics

Panics if the internal mutex is poisoned.

Trait Implementations

impl Clone for InMemoryFs

fn clone(&self) -> InMemoryFs

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for InMemoryFs

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

Formats the value using the given formatter.

impl Default for InMemoryFs

fn default() -> InMemoryFs

Returns the “default value” for a type.

impl Vfs for InMemoryFs

fn open_write(&self, path: &Path) -> Result<Box<dyn VfsWrite>>

Open path for writing, creating it if it does not exist.

fn open_read(&self, path: &Path) -> Result<Box<dyn VfsRead>>

Open path for reading.

fn create_dir_all(&self, path: &Path) -> Result<()>

Create path and every missing ancestor directory.

fn remove_file(&self, path: &Path) -> Result<()>

Remove the file at path.

fn remove_dir(&self, path: &Path) -> Result<()>

Remove the (empty) directory at path.

fn read_dir(&self, path: &Path) -> Result<Vec<PathBuf>>

Return entries directly inside path. Order is implementation-defined.

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

Return true if any entry exists at path.

fn metadata(&self, path: &Path) -> Result<VfsMetadata>

Return metadata for path. Returns NotFound if the path does not exist.