Struct vfs::file::vmo::VmoFile

pub struct VmoFile { /* private fields */ }

Implementation of a VMO-backed file in a virtual file system.

Implementations

impl VmoFile

pub fn new( vmo: Vmo, readable: bool, writable: bool, executable: bool, ) -> Arc<Self>

Create a new VmoFile which is backed by an existing Vmo.

Arguments

• vmo - Vmo backing this file object.
• readable - Must be true, VmoFile needs to be readable.
• writable - Must be false, VmoFile no longer supports writing.
• executable - If true, allow connections with OpenFlags::RIGHT_EXECUTABLE.

pub fn new_with_inode( vmo: Vmo, readable: bool, writable: bool, executable: bool, inode: u64, ) -> Arc<Self>

Create a new VmoFile with the specified options and inode value.

Arguments

• vmo - Vmo backing this file object.
• readable - Must be true, VmoFile needs to be readable.
• writable - Must be false, VmoFile no longer supports writing.
• executable - If true, allow connections with OpenFlags::RIGHT_EXECUTABLE.
• inode - Inode value to report when getting the VmoFile’s attributes.

Trait Implementations

impl DirectoryEntry for VmoFile

fn open_entry(self: Arc<Self>, request: OpenRequest<'_>) -> Result<(), Status>

Opens this entry.

impl File for VmoFile

fn readable(&self) -> bool

Capabilities:

fn writable(&self) -> bool

fn executable(&self) -> bool

async fn open_file(&self, _options: &FileOptions) -> Result<(), Status>

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():

async fn truncate(&self, _length: u64) -> Result<(), Status>

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.

async fn get_backing_memory(&self, flags: VmoFlags) -> Result<Vmo, Status>

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

async fn get_size(&self) -> Result<u64, Status>

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

async fn update_attributes( &self, _attributes: MutableNodeAttributes, ) -> Result<(), Status>

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.

async fn sync(&self, _mode: SyncMode) -> Result<(), Status>

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.

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.

impl FileLike for VmoFile

fn open( self: Arc<Self>, scope: ExecutionScope, options: FileOptions, object_request: ObjectRequestRef<'_>, ) -> Result<(), Status>

impl GetEntryInfo for VmoFile

fn entry_info(&self) -> EntryInfo

This method is used to populate ReadDirents() output.

impl GetVmo for VmoFile

fn get_vmo(&self) -> &Vmo

Returns the underlying VMO for the node.

const PAGER_ON_FIDL_EXECUTOR: bool = false

True if the vmo is pager backed and the pager is serviced by the same executor as the StreamIoConnection.

impl Node for VmoFile

async fn get_attributes( &self, requested_attributes: NodeAttributesQuery, ) -> Result<NodeAttributes2, Status>

Returns node attributes (io2).

fn will_open_as_node(&self) -> Result<(), Status>

Called when the node is about to be opened as the node protocol. Implementers can use this to perform any initialization or reference counting. Errors here will result in the open failing. By default, this forwards to the infallible will_clone.

fn will_clone(&self)

Called when the node is about to be cloned (and also by the default implementation of will_open_as_node). Implementations that perform their own open count can use this. Each call to will_clone will be accompanied by an eventual call to close.

fn close(self: Arc<Self>)

Called when the node is closed.

fn link_into( self: Arc<Self>, _destination_dir: Arc<dyn MutableDirectory>, _name: Name, ) -> impl Future<Output = Result<(), Status>> + Send

where Self: Sized,

fn query_filesystem(&self) -> Result<FilesystemInfo, Status>

Returns information about the filesystem.

fn open_as_node( self: Arc<Self>, scope: ExecutionScope, options: NodeOptions, object_request: ObjectRequestRef<'_>, ) -> Result<(), Status>

where Self: Sized,

Opens the node using the node protocol.

impl Sync for VmoFile