Struct File

pub struct File<'a> { /* private fields */ }

A file in the archive.

File objects allow standard operations on file inodes in an archive. File implements Read and Seek, so anything that reads files using standard Rust semantics can interact natively with these files. to_bytes and to_string offer convenience wrappers around this. Files that were archived with compression and fragmentation disabled can also be mmaped and accessed as an ordinary byte array.

let archive = Archive::new("archive.sfs")?;
let node = archive.get("/a/01.txt")?.unwrap().resolve()?;
let file = node.as_file()?;
// File can now be used like anything else that implements `Read` and `Seek`.
let mut buf = [0; 10];
file.seek(SeekFrom::End(-10))?;
file.read(&mut buf)?;

Implementations

impl<'a> File<'a>

pub fn size(&self) -> u64

Retrieve the size of the file in bytes.

pub fn to_bytes(&mut self) -> Result<Vec<u8>>

Retrieve the entire contents of the file in the form of a byte Vec.

pub fn to_string(&mut self) -> Result<String>

Retrieve the entire contents of the file in the form of a String.

This calls Read::read_to_string under the hood. Consequently, a UTF-8 error will be raised if the entire file is not valid UTF-8.

pub fn mmap<'b>(&'b mut self) -> Option<&'b [u8]>

Map a file into memory for fast parallel random access.

This uses mmap to map the file into memory. It will fail and return None if the file is compressed or fragmented. If the DontCompress and DontFragment options are set for a file at archive creation time, it will be added to the archive in one contiguous unmodified chunk. This is necessary because mmap provides a view into a file exactly as it is on-disk; there is no opportunity for the library to apply decompression or other transformations when mapping.

let map = file.mmap().expect("File is not mmappable");
println!("{}", str::from_utf8(map)?);

Trait Implementations

impl<'a> Debug for File<'a>

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

Formats the value using the given formatter.

impl<'a> Read for File<'a>

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

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>

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

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

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

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

Reads the exact number of bytes required to fill 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)

Reads 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<'a> Seek for File<'a>

fn seek(&mut self, pos: 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.