Struct WriteableStream 

pub struct WriteableStream { /* private fields */ }

Loose wrapper implementation of a stream on top of the File System Access API’s FileSystemWritableFileStream.

The page writes only asynchronously. write_async, flush_async and close_async are upstream’s WriteAsync, FlushAsync and DisposeAsync. The synchronous Write the storage contracts hand out issues the same writes without waiting for them (the browser cannot block): the script stream queues them in order, and write and flush report a failure that has already settled. Dropping the stream closes it, which commits the file once the queued writes are done. Until that close settles, the storage items wait before they open the same file or read its properties, and a failed write or close is logged and reported by the next opening of that file (see [settle_pending_closes]).

Implementations

impl WriteableStream

pub fn can_read(&self) -> bool

pub fn can_seek(&self) -> bool

pub fn can_write(&self) -> bool

pub fn length(&self) -> u64

pub fn position(&self) -> u64

pub fn set_position(&mut self, position: u64) -> Result<()>

Moves the position to position.

pub fn set_length(&mut self, value: u64) -> Result<()>

Resizes the file to value bytes.

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

Writes buffer at the position; resolves once the page has written it.

pub async fn flush_async(&mut self) -> Result<()>

Resolves once every write, seek and truncation issued through the synchronous members has settled, with the first failure among them.

pub async fn close_async(self) -> Result<()>

Closes the stream, which commits the written content to the file.

Trait Implementations

impl Drop for WriteableStream

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

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

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl Seek for WriteableStream

fn seek(&mut self, position: SeekFrom) -> Result<u64>

Seek to an offset, in bytes, in a stream.

fn rewind(&mut self) -> Result<(), Error>

Rewind to the beginning of a stream.

fn stream_len(&mut self) -> Result<u64, Error>

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

Returns the length of this stream (in bytes).

fn stream_position(&mut self) -> Result<u64, Error>

Returns the current seek position from the start of the stream.

fn seek_relative(&mut self, offset: i64) -> Result<(), Error>

Seeks relative to the current position.

impl Write for WriteableStream

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

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

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

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

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

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

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.