Trait HandleBackend 

pub trait HandleBackend {
    // Required methods
    fn sync_data(&mut self, tcf: &FileOperand) -> VfResult<()>;
    fn open_impl(&mut self, request: &OpenOp<'_>) -> VfResult<FileOperand>;
    fn close_impl(&mut self, file: &FileOperand) -> VfResult<()>;
    fn read_impl(&mut self, request: &ReadOp) -> VfResult<ReadResult>;
    fn write_impl(
        &mut self,
        request: WriteOp<&FileOperand, &[u8]>,
    ) -> VfResult<WriteResult>;
    fn seek_impl(
        &mut self,
        file: &FileOperand,
        position: SeekFrom,
    ) -> VfResult<u64>;
    fn metadata_impl(
        &mut self,
        target: Target<'_, FileOperand>,
        options: AttrsOptions,
    ) -> VfResult<VfAttrs>;
    fn set_attributes_impl(
        &mut self,
        update: &SetAttrsOp<Target<'_, FileOperand>>,
    ) -> VfResult<()>;

    // Provided methods
    fn prepare_object_refs(&mut self, _files: &[&FileOperand]) -> VfResult<()> { ... }
    fn open_object_ref(
        &self,
        _file: &FileOperand,
    ) -> VfResult<Option<OpenObjectRef<'_>>> { ... }
    fn vstatfs_impl(
        &mut self,
        files: &[FileOperand],
    ) -> VfResult<Vec<FilesystemStats>> { ... }
    fn close_deferred(&mut self, file: &FileOperand) -> VfResult<()> { ... }
    fn take_notifications(&mut self) -> Vec<Box<dyn FnOnce() + Send>> { ... }
    fn capabilities(&self) -> Capabilities { ... }
    fn abs_path(&self, path: &Path) -> PathBuf { ... }
    fn open_path_impl(
        &mut self,
        _base: VfPathBase,
        _pathname: &Path,
        _flags: i32,
        _mode: u32,
    ) -> VfResult<FileOperand> { ... }
    fn vfsync_impl(&mut self, files: &[FileOperand], mode: SyncMode) -> VfRes { ... }
    fn sync_all(&mut self, tcf: &FileOperand) -> VfResult<()> { ... }
    fn chdir(&mut self, _path: &Path) -> VfResult<()> { ... }
    fn getcwd(&self) -> PathBuf { ... }
    fn seek_raw_impl(
        &mut self,
        _tcf: &FileOperand,
        _offset: i64,
        _whence: SeekFrom,
    ) -> VfResult<i64> { ... }
    fn vf_path(&self, file: &FileOperand) -> VfResult<PathBuf> { ... }
    fn open_raw_impl(
        &mut self,
        pathname: &Path,
        flags: i32,
        mode: u32,
    ) -> VfResult<FileOperand> { ... }
    fn read_raw_impl(
        &mut self,
        file: &FileOperand,
        offset: u64,
        length: usize,
    ) -> VfResult<Vec<u8>> { ... }
    fn write_raw_impl(
        &mut self,
        file: &FileOperand,
        offset: u64,
        data: &[u8],
    ) -> VfResult<usize> { ... }
    fn read_file_impl(
        &mut self,
        file: &FileOperand,
        max_bytes: usize,
    ) -> VfResult<Vec<u8>> { ... }
    fn read_into_impl(
        &mut self,
        request: &ReadOp,
        buffer: &mut [u8],
    ) -> VfResult<ReadIntoResult> { ... }
    fn vsetattrs_impl(
        &mut self,
        updates: &[SetAttrsOp<Target<'_, FileOperand>>],
    ) -> VfResult<()> { ... }
}

Minimum contract for owned handles and descriptor lifecycle. This includes handle-level metadata/statistics hooks, but does not require namespace operations, directory enumeration, or native vector I/O.

Required Methods

fn sync_data(&mut self, tcf: &FileOperand) -> VfResult<()>

fn open_impl(&mut self, request: &OpenOp<'_>) -> VfResult<FileOperand>

fn close_impl(&mut self, file: &FileOperand) -> VfResult<()>

fn read_impl(&mut self, request: &ReadOp) -> VfResult<ReadResult>

fn write_impl( &mut self, request: WriteOp<&FileOperand, &[u8]>, ) -> VfResult<WriteResult>

fn seek_impl(&mut self, file: &FileOperand, position: SeekFrom) -> VfResult<u64>

fn metadata_impl( &mut self, target: Target<'_, FileOperand>, options: AttrsOptions, ) -> VfResult<VfAttrs>

Query a raw backend target with the same field/symlink options used by the application interface. Returned attributes retain target identity.

fn set_attributes_impl( &mut self, update: &SetAttrsOp<Target<'_, FileOperand>>, ) -> VfResult<()>

Apply one shared attribute operation. Raw timestamps and masks are converted by the backend, not exposed through a second mutation type.

Provided Methods

fn prepare_object_refs(&mut self, _files: &[&FileOperand]) -> VfResult<()>

Prepare object references in one backend batch when metadata is needed. Inputs retain request order so failure indices remain attributable. References returned for the batch must use a consistent, canonical representation. Return None when potentially aliased objects cannot be compared safely; unequal noncanonical filehandles are insufficient.

fn open_object_ref( &self, _file: &FileOperand, ) -> VfResult<Option<OpenObjectRef<'_>>>

Reference to the object pinned by a live File Descriptor, if available. Completion scheduling conservatively assumes aliasing when unknown. Saved paths and OPEN stateids must never be used as object references.

fn vstatfs_impl( &mut self, files: &[FileOperand], ) -> VfResult<Vec<FilesystemStats>>

fn close_deferred(&mut self, file: &FileOperand) -> VfResult<()>

fn take_notifications(&mut self) -> Vec<Box<dyn FnOnce() + Send>>

fn capabilities(&self) -> Capabilities

fn abs_path(&self, path: &Path) -> PathBuf

fn open_path_impl( &mut self, _base: VfPathBase, _pathname: &Path, _flags: i32, _mode: u32, ) -> VfResult<FileOperand>

fn vfsync_impl(&mut self, files: &[FileOperand], mode: SyncMode) -> VfRes

One backend synchronization vector. POSIX backends may loop under one lock because fsync has no vector syscall; protocol backends may batch.

fn sync_all(&mut self, tcf: &FileOperand) -> VfResult<()>

fn chdir(&mut self, _path: &Path) -> VfResult<()>

fn getcwd(&self) -> PathBuf

fn seek_raw_impl( &mut self, _tcf: &FileOperand, _offset: i64, _whence: SeekFrom, ) -> VfResult<i64>

fn vf_path(&self, file: &FileOperand) -> VfResult<PathBuf>

fn open_raw_impl( &mut self, pathname: &Path, flags: i32, mode: u32, ) -> VfResult<FileOperand>

fn read_raw_impl( &mut self, file: &FileOperand, offset: u64, length: usize, ) -> VfResult<Vec<u8>>

fn write_raw_impl( &mut self, file: &FileOperand, offset: u64, data: &[u8], ) -> VfResult<usize>

fn read_file_impl( &mut self, file: &FileOperand, max_bytes: usize, ) -> VfResult<Vec<u8>>

fn read_into_impl( &mut self, request: &ReadOp, buffer: &mut [u8], ) -> VfResult<ReadIntoResult>

fn vsetattrs_impl( &mut self, updates: &[SetAttrsOp<Target<'_, FileOperand>>], ) -> VfResult<()>

Borrow an ordered batch without transferring request ownership. Each operation carries its own final-symlink policy; native backends batch contiguous equal-policy runs and validate all inputs before I/O.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors