Struct wasi_common::fs::File

pub struct File<'ctx> { /* fields omitted */ }

A reference to an open file on the filesystem.

This corresponds to std::fs::File.

Note that this File has no open or create methods. To open or create a file, you must first obtain a Dir containing the file, and then call Dir::open_file or Dir::create_file.

Methods

impl<'ctx> File<'ctx>

pub unsafe fn from_raw_wasi_fd(ctx: &'ctx WasiCtx, fd: Fd) -> Self

Constructs a new instance of Self from the given raw WASI file descriptor.

This corresponds to std::fs::File::from_raw_fd.

pub fn sync_all(&self) -> Result<()>

Attempts to sync all OS-internal metadata to disk.

This corresponds to std::fs::File::sync_all.

pub fn sync_data(&self) -> Result<()>

This function is similar to sync_all, except that it may not synchronize file metadata to the filesystem.

This corresponds to std::fs::File::sync_data.

pub fn set_len(&self, size: u64) -> Result<()>

Truncates or extends the underlying file, updating the size of this file to become size.

This corresponds to std::fs::File::set_len.

pub fn metadata(&self) -> Result<Metadata>

Queries metadata about the underlying file.

This corresponds to std::fs::File::metadata.

Trait Implementations

impl<'ctx> Drop for File<'ctx>

fn drop(&mut self)

Executes the destructor for this type.

impl<'ctx> Read for File<'ctx>

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

TODO: Not yet implemented. See the comment in Dir::open_file.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

unsafe fn initializer(&self) -> Initializer

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

Determines if this Reader can work with buffers of uninitialized memory.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, appending them to buf.

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

Read the exact number of bytes required to fill buf.

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

Creates a "by reference" adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an [Iterator] over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read, 

Creates an adaptor which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

Creates an adaptor which will read at most limit bytes from it.