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use std::str;
use std::io::{self, Read};
use reqwest::Client;
use reqwest::header::Connection;
use failure::ResultExt;
use self::error::{DownloadError, ErrorKind};
/// Downloads the file and converts it to a String.
/// Any invalid bytes are converted to a replacement character.
///
/// The error indicated either a failed download or that the DownloadLimit was reached
pub fn download(url: &str, max_kib: Option<usize>) -> Result<String, DownloadError> {
let mut response = Client::new()
.get(url)
.header(Connection::close())
.send()
.context(ErrorKind::Connection)?;
// 100 kibibyte buffer
let mut buf = [0; 100 * 1024];
let mut written = 0;
let mut bytes = Vec::new();
// Read until we reach EOF or max_kib KiB
loop {
let len = match response.read(&mut buf) {
Ok(0) => break,
Ok(len) => len,
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,
Err(e) => Err(e).context(ErrorKind::Read)?,
};
bytes.extend_from_slice(&buf);
written += len;
// Check if the file is too large to download
if let Some(max_kib) = max_kib {
if written > max_kib * 1024 {
Err(ErrorKind::DownloadLimit)?;
}
}
}
Ok(String::from_utf8_lossy(&bytes).into_owned())
}
pub mod error {
#[derive(Copy, Clone, Eq, PartialEq, Debug, Fail, Error)]
#[error = "DownloadError"]
pub enum ErrorKind {
/// Connection Error
#[fail(display = "A connection error has occured")]
Connection,
/// Read Error
#[fail(display = "A read error has occured")]
Read,
/// Reached download limit error
#[fail(display = "Reached download limit")]
DownloadLimit,
}
}
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