Struct tokio_file_unix::File
[−]
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pub struct File<F> { /* fields omitted */ }
Used to wrap file-like objects so they can be used with
tokio_core::reactor::PollEvented
.
Normally, you should use File::new_nb
rather than File::raw_new
unless
the underlying file descriptor has already been set to nonblocking mode.
Using a file descriptor that is not in nonblocking mode for asynchronous
I/O will lead to subtle and confusing bugs.
Wrapping regular files has no effect because they do not support nonblocking mode.
impl Evented for File<std::fs::File>; impl Evented for File<StdFile<StdinLock>>; impl Evented for File<impl AsRawFd>;
Example: read standard input line by line
extern crate futures; extern crate tokio_core; extern crate tokio_io; extern crate tokio_file_unix; use futures::Stream; use tokio_io::{io, AsyncRead, AsyncWrite}; use tokio_io::codec::FramedRead; use tokio_file_unix::{File, StdFile}; // initialize the event loop let mut core = tokio_core::reactor::Core::new()?; let handle = core.handle(); // get the standard input as a file let stdin = std::io::stdin(); let reader = File::new_nb(StdFile(stdin.lock()))?.into_reader(&handle)?; // turn it into a stream of lines and process them let future = io::lines(reader).for_each(|line| { println!("Got: {}", line); Ok(()) }); // start the event loop core.run(future)?;
Example: unsafe creation from raw file descriptor
To unsafely create File<F>
from a raw file descriptor fd
, you can do
something like:
use std::os::unix::io::FromRawFd; let file = tokio_file_unix::File::new_nb(F::from_raw_fd(fd))?;
which will enable nonblocking mode upon creation. The choice of F
is
critical: it determines the ownership semantics of the file descriptor.
For example, if you choose F = std::fs::File
, the file descriptor will
be closed upon destruction.
Methods
impl<F: AsRawFd> File<F>
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fn new_nb(file: F) -> Result<Self>
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Wraps a file-like object so it can be used with
tokio_core::reactor::PollEvented
, and also enables nonblocking
mode on the underlying file descriptor.
fn new_nb(std::fs::File) -> Result<impl Evented + Read + Write>; fn new_nb(StdFile<StdinLock>) -> Result<impl Evented + Read>; fn new_nb(StdFile<StdoutLock>) -> Result<impl Evented + Write>; fn new_nb(StdFile<StderrLock>) -> Result<impl Evented + Write>; fn new_nb(impl AsRawFd) -> Result<impl Evented>;
fn set_nonblocking(&self, nonblocking: bool) -> Result<()>
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Sets the nonblocking mode of the underlying file descriptor to either
on (true
) or off (false
). If File::new_nb
was previously used
to construct the File
, then nonblocking mode has already been turned
on.
Implementation detail: uses fcntl
to set O_NONBLOCK
.
fn into_io(self, handle: &Handle) -> Result<PollEvented<Self>>
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Converts into a pollable object that supports tokio_io::AsyncRead
and tokio_io::AsyncWrite
, making it suitable for tokio_io::io::*
.
fn into_io(File<std::fs::File>, &Handle) -> Result<impl AsyncRead + AsyncWrite>; fn into_io(File<StdFile<StdinLock>>, &Handle) -> Result<impl AsyncRead + AsyncWrite>; fn into_io(File<impl AsRawFd + Read>, &Handle) -> Result<impl AsyncRead>; fn into_io(File<impl AsRawFd + Write>, &Handle) -> Result<impl AsyncWrite>;
impl<F: AsRawFd + Read> File<F>
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fn into_reader(self, handle: &Handle) -> Result<BufReader<PollEvented<Self>>>
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Converts into a pollable object that supports tokio_io::AsyncRead
and std::io::BufRead
, making it suitable for tokio_io::io::read_*
.
fn into_reader(File<std::fs::File>, &Handle) -> Result<impl AsyncRead + BufRead>; fn into_reader(File<StdFile<StdinLock>>, &Handle) -> Result<impl AsyncRead + BufRead>; fn into_reader(File<impl AsRawFd + Read>, &Handle) -> Result<impl AsyncRead + BufRead>;
impl<F> File<F>
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fn raw_new(file: F) -> Self
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Raw constructor that does not enable nonblocking mode on the underlying file descriptor. This constructor should only be used if you are certain that the underlying file descriptor is already in nonblocking mode.
Trait Implementations
impl<F: Debug> Debug for File<F>
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impl<F: AsRawFd> AsRawFd for File<F>
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impl<F: AsRawFd> Evented for File<F>
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fn register(
&self,
poll: &Poll,
token: Token,
interest: Ready,
opts: PollOpt
) -> Result<()>
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&self,
poll: &Poll,
token: Token,
interest: Ready,
opts: PollOpt
) -> Result<()>
Register self
with the given Poll
instance. Read more
fn reregister(
&self,
poll: &Poll,
token: Token,
interest: Ready,
opts: PollOpt
) -> Result<()>
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&self,
poll: &Poll,
token: Token,
interest: Ready,
opts: PollOpt
) -> Result<()>
Re-register self
with the given Poll
instance. Read more
fn deregister(&self, poll: &Poll) -> Result<()>
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Deregister self
from the given Poll
instance Read more
impl<F: Read> Read for File<F>
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fn read(&mut self, buf: &mut [u8]) -> Result<usize>
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Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
unsafe fn initializer(&self) -> Initializer
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read_initializer
)Determines if this Read
er can work with buffers of uninitialized memory. Read more
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>
1.0.0[src]
Read all bytes until EOF in this source, placing them into buf
. Read more
fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>
1.0.0[src]
Read all bytes until EOF in this source, placing them into buf
. Read more
fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>
1.6.0[src]
Read the exact number of bytes required to fill buf
. Read more
fn by_ref(&mut self) -> &mut Self
1.0.0[src]
Creates a "by reference" adaptor for this instance of Read
. Read more
fn bytes(self) -> Bytes<Self>
1.0.0[src]
Transforms this Read
instance to an [Iterator
] over its bytes. Read more
fn chars(self) -> Chars<Self>
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🔬 This is a nightly-only experimental API. (io
)
the semantics of a partial read/write of where errors happen is currently unclear and may change
Transforms this Read
instance to an [Iterator
] over [char
]s. Read more
fn chain<R>(self, next: R) -> Chain<Self, R> where
R: Read,
1.0.0[src]
R: Read,
Creates an adaptor which will chain this stream with another. Read more
fn take(self, limit: u64) -> Take<Self>
1.0.0[src]
Creates an adaptor which will read at most limit
bytes from it. Read more
impl<F: Write> Write for File<F>
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fn write(&mut self, buf: &[u8]) -> Result<usize>
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Write a buffer into this object, returning how many bytes were written. Read more
fn flush(&mut self) -> Result<()>
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Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>
1.0.0[src]
Attempts to write an entire buffer into this write. Read more
fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>
1.0.0[src]
Writes a formatted string into this writer, returning any error encountered. Read more
fn by_ref(&mut self) -> &mut Self
1.0.0[src]
Creates a "by reference" adaptor for this instance of Write
. Read more