dist: avoid recomputing dist root URL

Author: djc

src/config.rs

@@ -944,7 +944,7 @@ impl<'a> Cfg<'a> {
 
 /// The root path of the release server, without the `/dist` suffix.
 /// By default, it points to [`dist::DEFAULT_DIST_SERVER`].
-pub(crate) fn dist_root_server(process: &Process) -> Result<String> {
+fn dist_root_server(process: &Process) -> Result<String> {
     if let Some(s) = process.var_opt("RUSTUP_DIST_SERVER")? {
         trace!("`RUSTUP_DIST_SERVER` has been set to `{s}`");
         return Ok(s);

src/dist/download.rs

@@ -12,7 +12,7 @@ use tracing::{debug, info, warn};
 use url::Url;
 
 use super::{Channel, DEFAULT_DIST_SERVER, ToolchainDesc, temp};
-use crate::config::{Cfg, dist_root_server};
+use crate::config::Cfg;
 use crate::dist::manifest::Manifest;
 use crate::download::{download_file, download_file_with_resume};
 use crate::errors::RustupError;
@@ -138,11 +138,11 @@ impl<'a> DownloadCfg<'a> {
 
     pub(crate) async fn dl_v2_manifest(
         &self,
-        dist_root: &str,
         update_hash: Option<&Path>,
         toolchain: &ToolchainDesc,
+        cfg: &Cfg<'_>,
     ) -> Result<Option<(Manifest, String)>> {
-        let manifest_url = toolchain.manifest_v2_url(dist_root, self.process);
+        let manifest_url = toolchain.manifest_v2_url(&cfg.dist_root_url, self.process);
         match self
             .download_and_check(&manifest_url, update_hash, None, ".toml")
             .await
@@ -168,8 +168,7 @@ impl<'a> DownloadCfg<'a> {
                     // Manifest checksum mismatched.
                     warn!("{err}");
 
-                    let server = dist_root_server(self.process)?;
-                    if server == DEFAULT_DIST_SERVER {
+                    if cfg.dist_root_url.starts_with(DEFAULT_DIST_SERVER) {
                         info!(
                             "this is likely due to an ongoing update of the official release server, please try again later"
                         );
@@ -178,7 +177,8 @@ impl<'a> DownloadCfg<'a> {
                         );
                     } else {
                         info!(
-                            "this might indicate an issue with the third-party release server '{server}'"
+                            "this might indicate an issue with the third-party release server '{}'",
+                            cfg.dist_root_url
                         );
                         info!(
                             "see <https://github.com/rust-lang/rustup/issues/3885> for more details"

src/dist/mod.rs

@@ -1063,7 +1063,6 @@ impl<'a> DistOptions<'a> {
         match self
             .dl_cfg
             .dl_v2_manifest(
-                &self.cfg.dist_root_url,
                 // Even if manifest has not changed, we must continue to install requested components.
                 // So if components or targets is not empty, we skip passing `update_hash` so that
                 // we essentially degenerate to `rustup component add` / `rustup target add`
@@ -1073,6 +1072,7 @@ impl<'a> DistOptions<'a> {
                     None
                 },
                 self.toolchain,
+                self.cfg,
             )
             .await
         {

src/toolchain/distributable.rs

@@ -519,12 +519,12 @@ impl<'a> DistributableToolchain<'a> {
     }
 
     pub async fn show_dist_version(&self) -> anyhow::Result<Option<String>> {
-        let dist_root = &self.toolchain.cfg.dist_root_url;
-        let update_hash = self.toolchain.cfg.get_hash_file(&self.desc, false)?;
-        let download_cfg = DownloadCfg::new(self.toolchain.cfg);
-
-        match download_cfg
-            .dl_v2_manifest(dist_root, Some(&update_hash), &self.desc)
+        match DownloadCfg::new(self.toolchain.cfg)
+            .dl_v2_manifest(
+                Some(&self.toolchain.cfg.get_hash_file(&self.desc, false)?),
+                &self.desc,
+                self.toolchain.cfg,
+            )
             .await?
         {
             Some((manifest, _)) => Ok(Some(manifest.get_rust_version()?.to_string())),