Struct NamedFile

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

A Responder that sends file data with a Content-Type based on its file extension.

Example

A simple static file server mimicking FileServer:

use std::path::{PathBuf, Path};

use rocket::fs::{NamedFile, relative};

#[get("/file/<path..>")]
pub async fn second(path: PathBuf) -> Option<NamedFile> {
    let mut path = Path::new(relative!("static")).join(path);
    if path.is_dir() {
        path.push("index.html");
    }

    NamedFile::open(path).await.ok()
}

Always prefer to use FileServer which has more functionality and a pithier API.

Implementations

impl NamedFile

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

Attempts to open a file in read-only mode.

Errors

This function will return an error if path does not already exist. Other errors may also be returned according to OpenOptions::open().

Example

use rocket::fs::NamedFile;

#[get("/")]
async fn index() -> Option<NamedFile> {
    NamedFile::open("index.html").await.ok()
}

pub fn file(&self) -> &File

Retrieve the underlying File.

Example

use rocket::fs::NamedFile;

let named_file = NamedFile::open("index.html").await?;
let file = named_file.file();

pub fn file_mut(&mut self) -> &mut File

Retrieve a mutable borrow to the underlying File.

Example

use rocket::fs::NamedFile;

let mut named_file = NamedFile::open("index.html").await?;
let file = named_file.file_mut();

pub fn take_file(self) -> File

Take the underlying File.

Example

use rocket::fs::NamedFile;

let named_file = NamedFile::open("index.html").await?;
let file = named_file.take_file();

pub fn path(&self) -> &Path

Retrieve the path of this file.

Examples

use rocket::fs::NamedFile;

let file = NamedFile::open("foo.txt").await?;
assert_eq!(file.path().as_os_str(), "foo.txt");

Methods from Deref<Target = File>

pub async fn sync_all(&self) -> Result<(), Error>

Attempts to sync all OS-internal metadata to disk.

This function will attempt to ensure that all in-core data reaches the filesystem before returning.

Examples

use tokio::fs::File;
use tokio::io::AsyncWriteExt;

let mut file = File::create("foo.txt").await?;
file.write_all(b"hello, world!").await?;
file.sync_all().await?;

The write_all method is defined on the AsyncWriteExt trait.

pub async fn sync_data(&self) -> Result<(), Error>

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

This is intended for use cases that must synchronize content, but don’t need the metadata on disk. The goal of this method is to reduce disk operations.

Note that some platforms may simply implement this in terms of sync_all.

Examples

use tokio::fs::File;
use tokio::io::AsyncWriteExt;

let mut file = File::create("foo.txt").await?;
file.write_all(b"hello, world!").await?;
file.sync_data().await?;

The write_all method is defined on the AsyncWriteExt trait.

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

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

If the size is less than the current file’s size, then the file will be shrunk. If it is greater than the current file’s size, then the file will be extended to size and have all of the intermediate data filled in with 0s.

Errors

This function will return an error if the file is not opened for writing.

Examples

use tokio::fs::File;
use tokio::io::AsyncWriteExt;

let mut file = File::create("foo.txt").await?;
file.write_all(b"hello, world!").await?;
file.set_len(10).await?;

The write_all method is defined on the AsyncWriteExt trait.

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

Queries metadata about the underlying file.

Examples

use tokio::fs::File;

let file = File::open("foo.txt").await?;
let metadata = file.metadata().await?;

println!("{:?}", metadata);

pub async fn try_clone(&self) -> Result<File, Error>

Creates a new File instance that shares the same underlying file handle as the existing File instance. Reads, writes, and seeks will affect both File instances simultaneously.

Examples

use tokio::fs::File;

let file = File::open("foo.txt").await?;
let file_clone = file.try_clone().await?;

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

Changes the permissions on the underlying file.

Platform-specific behavior

This function currently corresponds to the fchmod function on Unix and the SetFileInformationByHandle function on Windows. Note that, this may change in the future.

Errors

This function will return an error if the user lacks permission change attributes on the underlying file. It may also return an error in other os-specific unspecified cases.

Examples

use tokio::fs::File;

let file = File::open("foo.txt").await?;
let mut perms = file.metadata().await?.permissions();
perms.set_readonly(true);
file.set_permissions(perms).await?;

pub fn set_max_buf_size(&mut self, max_buf_size: usize)

Set the maximum buffer size for the underlying AsyncRead / AsyncWrite operation.

Although Tokio uses a sensible default value for this buffer size, this function would be useful for changing that default depending on the situation.

Examples

use tokio::fs::File;
use tokio::io::AsyncWriteExt;

let mut file = File::open("foo.txt").await?;

// Set maximum buffer size to 8 MiB
file.set_max_buf_size(8 * 1024 * 1024);

let mut buf = vec![1; 1024 * 1024 * 1024];

// Write the 1 GiB buffer in chunks up to 8 MiB each.
file.write_all(&mut buf).await?;

Trait Implementations

impl Debug for NamedFile

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

Formats the value using the given formatter.

impl Deref for NamedFile

type Target = File

The resulting type after dereferencing.

fn deref(&self) -> &File

Dereferences the value.

impl DerefMut for NamedFile

fn deref_mut(&mut self) -> &mut File

Mutably dereferences the value.

impl<'r> Responder<'r, 'static> for NamedFile

Streams the named file to the client. Sets or overrides the Content-Type in the response according to the file’s extension if the extension is recognized. See ContentType::from_extension() for more information. If you would like to stream a file with a different Content-Type than that implied by its extension, use a File directly.

fn respond_to(self, req: &'r Request<'_>) -> Result<'static>

Returns Ok if a Response could be generated successfully. Otherwise, returns an Err with a failing Status.