Struct sync_file::SyncFile

pub struct SyncFile(/* private fields */);

A file wrapper that is safe to use concurrently.

This wrapper exists because std::fs::File uses a single cursor, so reading from a file concurrently will likely produce race conditions.

SyncFiles are cheap to clone and clones use distinct cursors, so they can be used concurrently without issues.

Implementations

impl SyncFile

pub fn open<P: AsRef<Path>>(path: P) -> Result<SyncFile>

Attempts to open a file in read-only mode.

See File::open for details.

pub fn create<P: AsRef<Path>>(path: P) -> Result<SyncFile>

Opens a file in write-only mode.

See File::create for details.

pub fn offset(&self) -> u64

Returns the offset used when reading the file.

This is equivalent to io::Seek::stream_position but does not use a fallible API nor require a mutable reference.

Methods from Deref<Target = RandomAccessFile>

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

Attempts to sync all OS-internal metadata to disk.

See File::sync_all for details.

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

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

See File::sync_data for details.

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

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

See File::set_len for details.

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

Queries metadata about the underlying file.

See File::metadata for details.

pub fn try_clone(&self) -> Result<RandomAccessFile>

Creates a new File instance that shares the same underlying file handle as the existing File instance

See File::try_clone for details.

pub fn set_permissions(&self, perm: Permissions) -> Result<()>

Changes the permissions on the underlying file.

See File::set_permissions for details.

Trait Implementations

impl AsFd for SyncFile

fn as_fd(&self) -> BorrowedFd<'_>

Borrows the file descriptor.

impl AsRawFd for SyncFile

fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor.

impl Clone for SyncFile

fn clone(&self) -> SyncFile

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SyncFile

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for SyncFile

type Target = RandomAccessFile

The resulting type after dereferencing.

fn deref(&self) -> &RandomAccessFile

Dereferences the value.

impl From<File> for SyncFile

fn from(file: File) -> SyncFile

Creates a new SyncFile from an open File.

The cursor starts at the beginning of the file.

impl From<OwnedFd> for SyncFile

fn from(fd: OwnedFd) -> Self

Converts to this type from the input type.

impl From<RandomAccessFile> for SyncFile

fn from(file: RandomAccessFile) -> SyncFile

Creates a new SyncFile from an open RandomAccessFile.

The cursor starts at the beginning of the file.

impl FromRawFd for SyncFile

unsafe fn from_raw_fd(fd: RawFd) -> Self

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

impl Read for SyncFile

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

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

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

Read the exact number of bytes required to fill buf.

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

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

fn is_read_vectored(&self) -> bool

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

Determines if this Reader has an efficient read_vectored implementation.

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_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

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

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

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

Read the exact number of bytes required to fill cursor.

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

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

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

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

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

where Self: Sized,

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

impl ReadAt for SyncFile

fn read_at(&self, buf: &mut [u8], offset: u64) -> Result<usize>

Reads a number of bytes starting from a given offset.

fn read_exact_at(&self, buf: &mut [u8], offset: u64) -> Result<()>

Reads the exact number of byte required to fill buf from the given offset.

fn read_vectored_at( &self, bufs: &mut [IoSliceMut<'_>], offset: u64 ) -> Result<usize>

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

impl Seek for SyncFile

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

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

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

Rewind to the beginning of a stream.

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

Returns the current seek position from the start of the 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 seek_relative(&mut self, offset: i64) -> Result<(), Error>

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

Seeks relative to the current position.

impl Write for SyncFile

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

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

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

Attempts to write an entire buffer into this writer.

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<()>

Flush 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_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, fmt: 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.

impl WriteAt for SyncFile

fn write_at(&self, buf: &[u8], offset: u64) -> Result<usize>

Writes a number of bytes starting from a given offset.

fn write_all_at(&self, buf: &[u8], offset: u64) -> Result<()>

Attempts to write an entire buffer starting from a given offset.

fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> Result<usize>

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

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

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