mirror of https://github.com/stjepang/smol
70 lines
2.0 KiB
Rust
70 lines
2.0 KiB
Rust
//! A simple HTTP+TLS client based on `async-native-tls`.
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//!
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//! Run with:
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//!
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//! ```
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//! cargo run --example simple-client
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//! ```
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use std::net::{TcpStream, ToSocketAddrs};
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use anyhow::{bail, Context as _, Result};
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use smol::{prelude::*, Async};
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use url::Url;
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/// Sends a GET request and fetches the response.
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async fn fetch(addr: &str) -> Result<Vec<u8>> {
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// Parse the URL.
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let url = Url::parse(addr)?;
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let host = url.host().context("cannot parse host")?.to_string();
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let port = url.port_or_known_default().context("cannot guess port")?;
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let path = url.path().to_string();
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let query = match url.query() {
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Some(q) => format!("?{}", q),
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None => String::new(),
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};
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// Construct a request.
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let req = format!(
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"GET {}{} HTTP/1.1\r\nHost: {}\r\nAccept: */*\r\nConnection: close\r\n\r\n",
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path, query, host,
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);
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// Connect to the host.
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let socket_addr = {
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let host = host.clone();
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smol::unblock(move || (host.as_str(), port).to_socket_addrs())
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.await?
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.next()
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.context("cannot resolve address")?
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};
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let mut stream = Async::<TcpStream>::connect(socket_addr).await?;
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// Send the request and wait for the response.
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let mut resp = Vec::new();
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match url.scheme() {
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"http" => {
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stream.write_all(req.as_bytes()).await?;
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stream.read_to_end(&mut resp).await?;
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}
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"https" => {
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// In case of HTTPS, establish a secure TLS connection first.
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let mut stream = async_native_tls::connect(&host, stream).await?;
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stream.write_all(req.as_bytes()).await?;
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stream.read_to_end(&mut resp).await?;
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}
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scheme => bail!("unsupported scheme: {}", scheme),
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}
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Ok(resp)
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}
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fn main() -> Result<()> {
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smol::block_on(async {
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let addr = "https://www.rust-lang.org";
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let resp = fetch(addr).await?;
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println!("{}", String::from_utf8_lossy(&resp));
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Ok(())
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})
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}
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