Find best download source out of alternatives (format extension)

Cargo.toml

@@ -10,8 +10,8 @@ edition = "2021"
 license = "GPL-3.0"
 
 [package.metadata.binstall]
-pkg-url = "{ repo }/releases/download/v{ version }/{ name }-{ target }.{ format }"
-bin-dir = "{ bin }{ format }"
+pkg-url = "{ repo }/releases/download/v{ version }/{ name }-{ target }.{ archive-format }"
+bin-dir = "{ bin }{ binary-ext }"
 
 [package.metadata.binstall.overrides.x86_64-pc-windows-msvc]
 pkg-fmt = "zip"

src/fetchers.rs

@@ -21,8 +21,15 @@ pub trait Fetcher: Send + Sync {
     /// Fetch a package and extract
     async fn fetch_and_extract(&self, dst: &Path) -> Result<(), BinstallError>;
 
-    /// Check if a package is available for download
-    async fn check(&self) -> Result<bool, BinstallError>;
+    /// Find the package, if it is available for download
+    ///
+    /// This may look for multiple remote targets, but must write (using some form of interior
+    /// mutability) the best one to the implementing struct in some way so `fetch_and_extract` can
+    /// proceed without additional work.
+    ///
+    /// Must return `true` if a package is available, `false` if none is, and reserve errors to
+    /// fatal conditions only.
+    async fn find(&self) -> Result<bool, BinstallError>;
 
     /// Return the package format
     fn pkg_fmt(&self) -> PkgFmt;
@@ -56,7 +63,7 @@ impl MultiFetcher {
     pub fn add(&mut self, fetcher: Arc<dyn Fetcher>) {
         self.0.push((
             fetcher.clone(),
-            AutoAbortJoinHandle::new(tokio::spawn(async move { fetcher.check().await })),
+            AutoAbortJoinHandle::new(tokio::spawn(async move { fetcher.find().await })),
         ));
     }
 

src/fetchers/gh_crate_meta.rs

@@ -2,25 +2,21 @@ use std::path::Path;
 use std::sync::Arc;
 
 use log::{debug, info, warn};
+use once_cell::sync::OnceCell;
 use reqwest::Client;
 use reqwest::Method;
 use serde::Serialize;
 use url::Url;
 
 use super::Data;
-use crate::{download_and_extract, remote_exists, BinstallError, PkgFmt, Template};
+use crate::{
+    download_and_extract, remote_exists, AutoAbortJoinHandle, BinstallError, PkgFmt, Template,
+};
 
 pub struct GhCrateMeta {
     client: Client,
     data: Data,
-}
-
-impl GhCrateMeta {
-    fn url(&self) -> Result<Url, BinstallError> {
-        let ctx = Context::from_data(&self.data);
-        debug!("Using context: {:?}", ctx);
-        ctx.render_url(&self.data.meta.pkg_url)
-    }
+    url: OnceCell<Url>,
 }
 
 #[async_trait::async_trait]
@@ -29,24 +25,52 @@ impl super::Fetcher for GhCrateMeta {
         Arc::new(Self {
             client: client.clone(),
             data: data.clone(),
+            url: OnceCell::new(),
         })
     }
 
-    async fn check(&self) -> Result<bool, BinstallError> {
-        let url = self.url()?;
+    async fn find(&self) -> Result<bool, BinstallError> {
+        // build up list of potential URLs
+        let urls = self.data.meta.pkg_fmt.extensions().iter().map(|ext| {
+            let ctx = Context::from_data(&self.data, ext);
+            ctx.render_url(&self.data.meta.pkg_url)
+        });
+
+        // go check all potential URLs at once
+        let checks = urls
+            .map(|url| {
+                let client = self.client.clone();
+                AutoAbortJoinHandle::new(tokio::spawn(async move {
+                    let url = url?;
+                    info!("Checking for package at: '{url}'");
+                    remote_exists(client, url.clone(), Method::HEAD)
+                        .await
+                        .map(|exists| (url.clone(), exists))
+                }))
+            })
+            .collect::<Vec<_>>();
+
+        // get the first URL that exists
+        for check in checks {
+            let (url, exists) = check.await??;
+            if exists {
+                if url.scheme() != "https" {
+                    warn!(
+                        "URL is not HTTPS! This may become a hard error in the future, tell the upstream!"
+                    );
+                }
 
-        if url.scheme() != "https" {
-            warn!(
-                "URL is not HTTPS! This may become a hard error in the future, tell the upstream!"
-            );
+                info!("Winning URL is {url}");
+                self.url.set(url).unwrap(); // find() is called first
+                return Ok(true);
+            }
         }
 
-        info!("Checking for package at: '{url}'");
-        remote_exists(&self.client, url, Method::HEAD).await
+        Ok(false)
     }
 
     async fn fetch_and_extract(&self, dst: &Path) -> Result<(), BinstallError> {
-        let url = self.url()?;
+        let url = self.url.get().unwrap(); // find() is called first
         info!("Downloading package from: '{url}'");
         download_and_extract(&self.client, url, self.pkg_fmt(), dst).await
     }
@@ -56,7 +80,8 @@ impl super::Fetcher for GhCrateMeta {
     }
 
     fn source_name(&self) -> String {
-        self.url()
+        self.url
+            .get()
             .map(|url| {
                 if let Some(domain) = url.domain() {
                     domain.to_string()
@@ -66,7 +91,7 @@ impl super::Fetcher for GhCrateMeta {
                     url.to_string()
                 }
             })
-            .unwrap_or_else(|_| "invalid url template".to_string())
+            .unwrap_or_else(|| "invalid url".to_string())
     }
 
     fn is_third_party(&self) -> bool {
@@ -87,11 +112,11 @@ struct Context<'c> {
     pub version: &'c str,
 
     /// Soft-deprecated alias for archive-format
-    pub format: String,
+    pub format: &'c str,
 
     /// Archive format e.g. tar.gz, zip
     #[serde(rename = "archive-format")]
-    pub archive_format: String,
+    pub archive_format: &'c str,
 
     /// Filename extension on the binary, i.e. .exe on Windows, nothing otherwise
     #[serde(rename = "binary-ext")]
@@ -101,15 +126,14 @@ struct Context<'c> {
 impl<'c> Template for Context<'c> {}
 
 impl<'c> Context<'c> {
-    pub(self) fn from_data(data: &'c Data) -> Self {
-        let pkg_fmt = data.meta.pkg_fmt.to_string();
+    pub(self) fn from_data(data: &'c Data, archive_format: &'c str) -> Self {
         Self {
             name: &data.name,
             repo: data.repo.as_ref().map(|s| &s[..]),
             target: &data.target,
             version: &data.version,
-            format: pkg_fmt.clone(),
-            archive_format: pkg_fmt,
+            format: archive_format,
+            archive_format,
             binary_ext: if data.target.contains("windows") {
                 ".exe"
             } else {
@@ -119,6 +143,7 @@ impl<'c> Context<'c> {
     }
 
     pub(self) fn render_url(&self, template: &str) -> Result<Url, BinstallError> {
+        debug!("Render {template:?} using context: {:?}", self);
         Ok(Url::parse(&self.render(template)?)?)
     }
 }
@@ -144,7 +169,7 @@ mod test {
             meta,
         };
 
-        let ctx = Context::from_data(&data);
+        let ctx = Context::from_data(&data, "tgz");
         assert_eq!(
             ctx.render_url(&data.meta.pkg_url).unwrap(),
             url("https://github.com/ryankurte/cargo-binstall/releases/download/v1.2.3/cargo-binstall-x86_64-unknown-linux-gnu-v1.2.3.tgz")
@@ -163,7 +188,7 @@ mod test {
             meta,
         };
 
-        let ctx = Context::from_data(&data);
+        let ctx = Context::from_data(&data, "tgz");
         ctx.render_url(&data.meta.pkg_url).unwrap();
     }
 
@@ -182,7 +207,7 @@ mod test {
             meta,
         };
 
-        let ctx = Context::from_data(&data);
+        let ctx = Context::from_data(&data, "tgz");
         assert_eq!(
             ctx.render_url(&data.meta.pkg_url).unwrap(),
             url("https://example.com/releases/download/v1.2.3/cargo-binstall-x86_64-unknown-linux-gnu-v1.2.3.tgz")
@@ -206,7 +231,7 @@ mod test {
             meta,
         };
 
-        let ctx = Context::from_data(&data);
+        let ctx = Context::from_data(&data, "tgz");
         assert_eq!(
             ctx.render_url(&data.meta.pkg_url).unwrap(),
             url("https://github.com/rust-iot/rust-radio-sx128x/releases/download/v0.14.1-alpha.5/sx128x-util-x86_64-unknown-linux-gnu-v0.14.1-alpha.5.tgz")
@@ -228,7 +253,7 @@ mod test {
             meta,
         };
 
-        let ctx = Context::from_data(&data);
+        let ctx = Context::from_data(&data, "tgz");
         assert_eq!(
             ctx.render_url(&data.meta.pkg_url).unwrap(),
             url("https://github.com/rust-iot/rust-radio-sx128x/releases/download/v0.14.1-alpha.5/sx128x-util-x86_64-unknown-linux-gnu-v0.14.1-alpha.5.tgz")
@@ -253,7 +278,7 @@ mod test {
             meta,
         };
 
-        let ctx = Context::from_data(&data);
+        let ctx = Context::from_data(&data, "txz");
         assert_eq!(
             ctx.render_url(&data.meta.pkg_url).unwrap(),
             url("https://github.com/watchexec/cargo-watch/releases/download/v9.0.0/cargo-watch-v9.0.0-aarch64-apple-darwin.tar.xz")
@@ -276,7 +301,7 @@ mod test {
             meta,
         };
 
-        let ctx = Context::from_data(&data);
+        let ctx = Context::from_data(&data, "bin");
         assert_eq!(
             ctx.render_url(&data.meta.pkg_url).unwrap(),
             url("https://github.com/watchexec/cargo-watch/releases/download/v9.0.0/cargo-watch-v9.0.0-aarch64-pc-windows-msvc.exe")

src/fetchers/quickinstall.rs

@@ -32,17 +32,17 @@ impl super::Fetcher for QuickInstall {
         })
     }
 
-    async fn check(&self) -> Result<bool, BinstallError> {
+    async fn find(&self) -> Result<bool, BinstallError> {
         let url = self.package_url();
         self.report();
         info!("Checking for package at: '{url}'");
-        remote_exists(&self.client, Url::parse(&url)?, Method::HEAD).await
+        remote_exists(self.client.clone(), Url::parse(&url)?, Method::HEAD).await
     }
 
     async fn fetch_and_extract(&self, dst: &Path) -> Result<(), BinstallError> {
         let url = self.package_url();
         info!("Downloading package from: '{url}'");
-        download_and_extract(&self.client, Url::parse(&url)?, self.pkg_fmt(), dst).await
+        download_and_extract(&self.client, &Url::parse(&url)?, self.pkg_fmt(), dst).await
     }
 
     fn pkg_fmt(&self) -> PkgFmt {

src/formats.rs

@@ -1,11 +1,8 @@
 use serde::{Deserialize, Serialize};
-use strum_macros::{Display, EnumString, EnumVariantNames};
+use strum_macros::{Display, EnumString};
 
 /// Binary format enumeration
-#[derive(
-    Debug, Copy, Clone, PartialEq, Serialize, Deserialize, Display, EnumString, EnumVariantNames,
-)]
-#[strum(serialize_all = "snake_case")]
+#[derive(Debug, Copy, Clone, PartialEq, Serialize, Deserialize, EnumString)]
 #[serde(rename_all = "snake_case")]
 pub enum PkgFmt {
     /// Download format is TAR (uncompressed)
@@ -31,8 +28,7 @@ impl Default for PkgFmt {
 }
 
 impl PkgFmt {
-    /// If self is one of the tar based formats,
-    /// return Some.
+    /// If self is one of the tar based formats, return Some.
     pub fn decompose(self) -> PkgFmtDecomposed {
         match self {
             PkgFmt::Tar => PkgFmtDecomposed::Tar(TarBasedFmt::Tar),
@@ -44,6 +40,19 @@ impl PkgFmt {
             PkgFmt::Zip => PkgFmtDecomposed::Zip,
         }
     }
+
+    /// List of possible file extensions for the format.
+    pub fn extensions(self) -> &'static [&'static str] {
+        match self {
+            PkgFmt::Tar => &["tar"],
+            PkgFmt::Tbz2 => &["tbz2", "tar.bz2"],
+            PkgFmt::Tgz => &["tgz", "tar.gz"],
+            PkgFmt::Txz => &["txz", "tar.xz"],
+            PkgFmt::Tzstd => &["tzstd", "tzst", "tar.zst"],
+            PkgFmt::Bin => &["bin", "exe"],
+            PkgFmt::Zip => &["zip"],
+        }
+    }
 }
 
 #[derive(Debug, Copy, Clone, PartialEq)]

src/helpers.rs

@@ -113,7 +113,7 @@ pub fn create_reqwest_client(
 }
 
 pub async fn remote_exists(
-    client: &Client,
+    client: Client,
     url: Url,
     method: Method,
 ) -> Result<bool, BinstallError> {
@@ -147,11 +147,11 @@ async fn create_request(
 /// Download a file from the provided URL and extract it to the provided path.
 pub async fn download_and_extract<P: AsRef<Path>>(
     client: &Client,
-    url: Url,
+    url: &Url,
     fmt: PkgFmt,
     path: P,
 ) -> Result<(), BinstallError> {
-    let stream = create_request(client, url).await?;
+    let stream = create_request(client, url.clone()).await?;
 
     let path = path.as_ref();
     debug!("Downloading and extracting to: '{}'", path.display());

src/lib.rs

@@ -137,7 +137,7 @@ mod test {
 
         assert_eq!(
             &meta.pkg_url,
-            "{ repo }/releases/download/v{ version }/{ name }-{ target }.{ format }"
+            "{ repo }/releases/download/v{ version }/{ name }-{ target }.{ archive-format }"
         );
 
         assert_eq!(