Trait vfs::file::File

pub trait File: Node {
    // Required methods
    fn open_file(
        &self,
        options: &FileOptions,
    ) -> impl Future<Output = Result<(), Status>> + Send;
    fn truncate(
        &self,
        length: u64,
    ) -> impl Future<Output = Result<(), Status>> + Send;
    fn get_backing_memory(
        &self,
        flags: VmoFlags,
    ) -> impl Future<Output = Result<Vmo, Status>> + Send;
    fn get_size(&self) -> impl Future<Output = Result<u64, Status>> + Send;
    fn update_attributes(
        &self,
        attributes: MutableNodeAttributes,
    ) -> impl Future<Output = Result<(), Status>> + Send;
    fn sync(
        &self,
        mode: SyncMode,
    ) -> impl Future<Output = Result<(), Status>> + Send;

    // Provided methods
    fn readable(&self) -> bool { ... }
    fn writable(&self) -> bool { ... }
    fn executable(&self) -> bool { ... }
    fn list_extended_attributes(
        &self,
    ) -> impl Future<Output = Result<Vec<Vec<u8>>, Status>> + Send { ... }
    fn get_extended_attribute(
        &self,
        _name: Vec<u8>,
    ) -> impl Future<Output = Result<Vec<u8>, Status>> + Send { ... }
    fn set_extended_attribute(
        &self,
        _name: Vec<u8>,
        _value: Vec<u8>,
        _mode: SetExtendedAttributeMode,
    ) -> impl Future<Output = Result<(), Status>> + Send { ... }
    fn remove_extended_attribute(
        &self,
        _name: Vec<u8>,
    ) -> impl Future<Output = Result<(), Status>> + Send { ... }
    fn allocate(
        &self,
        _offset: u64,
        _length: u64,
        _mode: AllocateMode,
    ) -> impl Future<Output = Result<(), Status>> + Send { ... }
    fn enable_verity(
        &self,
        _options: VerificationOptions,
    ) -> impl Future<Output = Result<(), Status>> + Send { ... }
    fn event(&self) -> Result<Option<Event>, Status> { ... }
}

Trait used for all files.

Required Methods

fn open_file( &self, options: &FileOptions, ) -> impl Future<Output = Result<(), Status>> + Send

Called when the file is going to be accessed, typically by a new connection. Flags is the same as the flags passed to fidl_fuchsia_io.Node/Open. The following flags are handled by the connection and do not need to be handled inside open():

• OPEN_FLAG_TRUNCATE - A call to truncate() will be made immediately after open().
• OPEN_FLAG_DESCRIBE - The OnOpen event is sent before any other requests are received from the file’s client.

fn truncate( &self, length: u64, ) -> impl Future<Output = Result<(), Status>> + Send

Truncate the file to length. If there are pending attributes to update (see update_attributes), they should also be flushed at this time. Otherwise, no attributes should be updated, other than size as needed.

fn get_backing_memory( &self, flags: VmoFlags, ) -> impl Future<Output = Result<Vmo, Status>> + Send

Get a VMO representing this file. If not supported by the underlying filesystem, should return Err(NOT_SUPPORTED).

fn get_size(&self) -> impl Future<Output = Result<u64, Status>> + Send

Get the size of this file. This is used to calculate seek offset relative to the end.

fn update_attributes( &self, attributes: MutableNodeAttributes, ) -> impl Future<Output = Result<(), Status>> + Send

Set the mutable attributes of this file based on the values in attributes. If the file does not support updating all of the specified attributes, implementations should fail with ZX_ERR_NOT_SUPPORTED.

fn sync( &self, mode: SyncMode, ) -> impl Future<Output = Result<(), Status>> + Send

Sync this file’s contents to the storage medium (probably disk). This does not necessarily guarantee that the file will be completely written to disk once the call returns. It merely guarantees that any changes to the file have been propagated to the next layer in the storage stack.

Provided Methods

fn readable(&self) -> bool

Capabilities:

fn writable(&self) -> bool

fn executable(&self) -> bool

fn list_extended_attributes( &self, ) -> impl Future<Output = Result<Vec<Vec<u8>>, Status>> + Send

List this files extended attributes.

fn get_extended_attribute( &self, _name: Vec<u8>, ) -> impl Future<Output = Result<Vec<u8>, Status>> + Send

Get the value for an extended attribute.

fn set_extended_attribute( &self, _name: Vec<u8>, _value: Vec<u8>, _mode: SetExtendedAttributeMode, ) -> impl Future<Output = Result<(), Status>> + Send

Set the value for an extended attribute.

fn remove_extended_attribute( &self, _name: Vec<u8>, ) -> impl Future<Output = Result<(), Status>> + Send

Remove the value for an extended attribute.

fn allocate( &self, _offset: u64, _length: u64, _mode: AllocateMode, ) -> impl Future<Output = Result<(), Status>> + Send

Preallocate disk space for this range.

fn enable_verity( &self, _options: VerificationOptions, ) -> impl Future<Output = Result<(), Status>> + Send

Set the merkle tree and the descriptor for this file and mark the file as fsverity-enabled.

fn event(&self) -> Result<Option<Event>, Status>

Returns an optional event for the file which signals fuchsia.io2.FileSignal events to clients (e.g. when a file becomes readable). See fuchsia.io2.File.Describe.

Object Safety

This trait is not object safe.

Implementors

impl File for VmoFile