Struct VirtioFsWriter 

pub struct VirtioFsWriter<'a, S = ()> { /* private fields */ }

Provide high-level interface over the sequence of memory regions defined by writable descriptors in the Virtio descriptor chain.

Note that virtio spec requires driver to place any device-writable descriptors after any device-readable descriptors (2.6.4.2 in Virtio Spec v1.1). Writer will start iterating the descriptors from the first writable one and will assume that all following descriptors are writable.

Implementations

impl<'a, S: BitmapSlice> VirtioFsWriter<'a, S>

pub async fn async_write(&mut self, data: &[u8]) -> Result<usize>

Write data from a buffer into this writer in asynchronous mode.

pub async fn async_write2(&mut self, data: &[u8], data2: &[u8]) -> Result<usize>

Write data from two buffers into this writer in asynchronous mode.

pub async fn async_write3( &mut self, data: &[u8], data2: &[u8], data3: &[u8], ) -> Result<usize>

Write data from three buffers into this writer in asynchronous mode.

pub async fn async_write_all(&mut self, buf: &[u8]) -> Result<()>

Attempts to write an entire buffer into this writer in asynchronous mode.

pub async fn async_write_from_at<F: AsyncFileReadWriteVolatile>( &mut self, src: &F, count: usize, off: u64, ) -> Result<usize>

Writes data to the descriptor chain buffer from a File at offset off. Returns the number of bytes written to the descriptor chain buffer.

pub async fn async_commit( &mut self, other: Option<&Writer<'a, S>>, ) -> Result<usize>

Commit all internal buffers of self and others We need this because the lifetime of others is usually shorter than self.

impl<'a> VirtioFsWriter<'a>

pub fn new<M>( mem: &'a M::Target, desc_chain: DescriptorChain<M>, ) -> Result<VirtioFsWriter<'a, MS<'a, M::Target>>>

where M: Deref, M::Target: GuestMemory + Sized,

Construct a new Writer wrapper over desc_chain.

impl<'a, S: BitmapSlice> VirtioFsWriter<'a, S>

pub fn write_obj<T: ByteValued>(&mut self, val: T) -> Result<()>

Write an object to the descriptor chain buffer.

pub fn write_from<F: FileReadWriteVolatile>( &mut self, src: F, count: usize, ) -> Result<usize>

Write data to the descriptor chain buffer from a file descriptor.

Return the number of bytes written to the descriptor chain buffer.

pub fn write_from_at<F: FileReadWriteVolatile>( &mut self, src: F, count: usize, off: u64, ) -> Result<usize>

Write data to the descriptor chain buffer from a File at offset off.

Return the number of bytes written to the descriptor chain buffer.

pub fn write_all_from<F: FileReadWriteVolatile>( &mut self, src: F, count: usize, ) -> Result<()>

Write all data to the descriptor chain buffer from a file descriptor.

pub fn available_bytes(&self) -> usize

Return number of bytes available for writing.

May return an error if the combined lengths of all the buffers in the DescriptorChain would cause an overflow.

pub fn bytes_written(&self) -> usize

Return number of bytes already written to the descriptor chain buffer.

pub fn split_at(&mut self, offset: usize) -> Result<Self>

Split this Writer into two at the given offset in the DescriptorChain buffer. After the split, self will be able to write up to offset bytes while the returned Writer can write up to available_bytes() - offset bytes. Returns an error if offset > self.available_bytes().

pub fn commit(&mut self, _other: Option<&Writer<'a, S>>) -> Result<usize>

Commit all internal buffers of self and others

This is provided just to be compatible with fusedev

Trait Implementations

impl<'a, S: Clone> Clone for VirtioFsWriter<'a, S>

fn clone(&self) -> VirtioFsWriter<'a, S>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a, S: BitmapSlice> From<VirtioFsWriter<'a, S>> for Writer<'a, S>

fn from(w: VirtioFsWriter<'a, S>) -> Self

Converts to this type from the input type.

impl<S: BitmapSlice> Write for VirtioFsWriter<'_, S>

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize>

Like write, except that it writes from a slice of buffers.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.