Fix: Provide timeouts for reading from sockets (#93)

* Provide timeouts for reading from sockets

When Microsoft's CDNs are having a bad day, or when a user has limited
bandwidth, the download process can stall and die permanently.
This change allows xwin to recognise when this has happened and do something about it.

* Allow user configuration of timeout

* Default to 60s if user does not specify

---------

Co-authored-by: Jake Shadle <jake.shadle@embark-studios.com>

src/ctx.rs

@@ -1,3 +1,5 @@
+use std::time::Duration;
+
 use crate::{
     splat::SdkHeaders,
     util::{ProgressTarget, Sha256},
@@ -23,33 +25,31 @@ pub struct Ctx {
 }
 
 impl Ctx {
-    fn http_client() -> Result<ureq::Agent, Error> {
+    fn http_client(read_timeout: Option<Duration>) -> Result<ureq::Agent, Error> {
+        let mut builder = ureq::builder();
+
         #[cfg(feature = "native-tls")]
         {
             use std::sync::Arc;
-            let mut builder =
-                ureq::builder().tls_connector(Arc::new(native_tls_crate::TlsConnector::new()?));
-            if let Ok(proxy) = std::env::var("https_proxy") {
-                let proxy = ureq::Proxy::new(proxy)?;
-                builder = builder.proxy(proxy);
-            };
-            Ok(builder.build())
+            builder = builder.tls_connector(Arc::new(native_tls_crate::TlsConnector::new()?));
         }
 
-        #[cfg(not(feature = "native-tls"))]
-        {
-            let mut builder = ureq::builder();
-            if let Ok(proxy) = std::env::var("https_proxy") {
-                let proxy = ureq::Proxy::new(proxy)?;
-                builder = builder.proxy(proxy);
-            };
-            Ok(builder.build())
+        // Allow user to specify timeout values in the case of bad/slow proxies
+        // or MS itself being terrible, but default to a minute, which is _far_
+        // more than it should take in normal situations, as by default ureq
+        // sets no timeout on the response
+        builder = builder.timeout_read(read_timeout.unwrap_or(Duration::from_secs(60)));
+
+        if let Ok(proxy) = std::env::var("https_proxy") {
+            let proxy = ureq::Proxy::new(proxy)?;
+            builder = builder.proxy(proxy);
         }
+        Ok(builder.build())
     }
 
-    pub fn with_temp(dt: ProgressTarget) -> Result<Self, Error> {
+    pub fn with_temp(dt: ProgressTarget, read_timeout: Option<Duration>) -> Result<Self, Error> {
         let td = tempfile::TempDir::new()?;
-        let client = Self::http_client()?;
+        let client = Self::http_client(read_timeout)?;
 
         Ok(Self {
             work_dir: PathBuf::from_path_buf(td.path().to_owned()).map_err(|pb| {
@@ -61,8 +61,12 @@ impl Ctx {
         })
     }
 
-    pub fn with_dir(mut work_dir: PathBuf, dt: ProgressTarget) -> Result<Self, Error> {
-        let client = Self::http_client()?;
+    pub fn with_dir(
+        mut work_dir: PathBuf,
+        dt: ProgressTarget,
+        read_timeout: Option<Duration>,
+    ) -> Result<Self, Error> {
+        let client = Self::http_client(read_timeout)?;
 
         work_dir.push("dl");
         std::fs::create_dir_all(&work_dir)?;

src/main.rs

@@ -3,6 +3,7 @@ use camino::Utf8PathBuf as PathBuf;
 use clap::builder::{PossibleValuesParser, TypedValueParser as _};
 use clap::{Parser, Subcommand};
 use indicatif as ia;
+use std::time::Duration;
 use tracing_subscriber::filter::LevelFilter;
 
 fn setup_logger(json: bool, log_level: LevelFilter) -> Result<(), Error> {
@@ -89,7 +90,30 @@ const LOG_LEVELS: &[&str] = &["off", "error", "warn", "info", "debug", "trace"];
 
 fn parse_level(s: &str) -> Result<LevelFilter, Error> {
     s.parse::<LevelFilter>()
-        .map_err(|_| anyhow::anyhow!("failed to parse level '{}'", s))
+        .map_err(|_| anyhow::anyhow!("failed to parse level '{s}'"))
+}
+
+#[allow(clippy::indexing_slicing)]
+fn parse_duration(src: &str) -> anyhow::Result<Duration> {
+    let suffix_pos = src.find(char::is_alphabetic).unwrap_or(src.len());
+
+    let num: u64 = src[..suffix_pos].parse()?;
+    let suffix = if suffix_pos == src.len() {
+        "s"
+    } else {
+        &src[suffix_pos..]
+    };
+
+    let duration = match suffix {
+        "ms" => Duration::from_millis(num),
+        "s" | "S" => Duration::from_secs(num),
+        "m" | "M" => Duration::from_secs(num * 60),
+        "h" | "H" => Duration::from_secs(num * 60 * 60),
+        "d" | "D" => Duration::from_secs(num * 60 * 60 * 24),
+        s => anyhow::bail!("unknown duration suffix '{s}'"),
+    };
+
+    Ok(duration)
 }
 
 #[derive(Parser)]
@@ -131,6 +155,9 @@ pub struct Args {
     /// Whether to include the Active Template Library (ATL) in the installation
     #[arg(long)]
     include_atl: bool,
+    /// Specifies a timeout for how long a single download is allowed to take. The default is 60s.
+    #[arg(short, long, value_parser = parse_duration)]
+    timeout: Option<Duration>,
     /// The architectures to include
     #[arg(
         long,
@@ -176,13 +203,13 @@ fn main() -> Result<(), Error> {
     let draw_target = xwin::util::ProgressTarget::Stdout;
 
     let ctx = if args.temp {
-        xwin::Ctx::with_temp(draw_target)?
+        xwin::Ctx::with_temp(draw_target, args.timeout)?
     } else {
         let cache_dir = match &args.cache_dir {
             Some(cd) => cd.clone(),
             None => cwd.join(".xwin-cache"),
         };
-        xwin::Ctx::with_dir(cache_dir, draw_target)?
+        xwin::Ctx::with_dir(cache_dir, draw_target, args.timeout)?
     };
 
     let ctx = std::sync::Arc::new(ctx);

tests/compiles.rs

@@ -3,6 +3,7 @@ fn verify_compiles() {
     let ctx = xwin::Ctx::with_dir(
         xwin::PathBuf::from(".xwin-cache/compile-test"),
         xwin::util::ProgressTarget::Hidden,
+        None,
     )
     .unwrap();
 

tests/deterministic.rs

@@ -6,6 +6,7 @@ fn verify_deterministic() {
     let ctx = xwin::Ctx::with_dir(
         PathBuf::from(".xwin-cache/deterministic"),
         xwin::util::ProgressTarget::Hidden,
+        None,
     )
     .unwrap();
 

tests/snapshots/xwin.snap

@@ -60,6 +60,10 @@ Options:
           Whether to include the Active Template Library (ATL) in the
           installation
 
+  -t, --timeout <TIMEOUT>
+          Specifies a timeout for how long a single download is allowed to take.
+          The default is 60s
+
       --arch <ARCH>
           The architectures to include