fix: don't block executor with integrity checking

src/content/read.rs

@@ -118,15 +118,23 @@ pub fn read(cache: &Path, sri: &Integrity) -> Result<Vec<u8>> {
 }
 
 #[cfg(any(feature = "async-std", feature = "tokio"))]
-pub async fn read_async<'a>(cache: &'a Path, sri: &'a Integrity) -> Result<Vec<u8>> {
-    let cpath = path::content_path(cache, sri);
+pub async fn read_async<'c, 's>(cache: &'c Path, sri: Integrity) -> Result<Vec<u8>> {
+    // let cache = cache.to_path_buf();
+    let cpath = path::content_path(&cache, &sri);
     let ret = crate::async_lib::read(&cpath).await.with_context(|| {
         format!(
             "Failed to read contents for file at {}",
-            path::content_path(cache, sri).display()
+            path::content_path(&cache, &sri).display()
         )
     })?;
-    sri.check(&ret)?;
+    let integrity_check = move || {
+        sri.check(&ret)?;
+        Ok::<_, ssri::Error>(ret)
+    };
+    #[cfg(feature = "tokio")]
+    let ret = tokio::task::spawn_blocking(integrity_check).await??;
+    #[cfg(feature = "async-std")]
+    let ret = async_std::task::spawn_blocking(integrity_check).await?;
     Ok(ret)
 }
 

src/errors.rs

@@ -31,6 +31,12 @@ pub enum Error {
     #[error(transparent)]
     #[diagnostic(code(cacache::integrity_error), url(docsrs))]
     IntegrityError(#[from] ssri::Error),
+
+    /// Returned when a Tokio join error occured.
+    #[cfg(feature="tokio")]
+    #[error(transparent)]
+    #[diagnostic(code(cacache::tokio_joinerror), url(docsrs))]
+    TokioJoinError(#[from] tokio::task::JoinError)
 }
 
 /// The result type returned by calls to this library

src/get.rs

@@ -159,7 +159,7 @@ where
 {
     async fn inner(cache: &Path, key: &str) -> Result<Vec<u8>> {
         if let Some(entry) = index::find_async(cache, key).await? {
-            read_hash(cache, &entry.integrity).await
+            read_hash(cache, entry.integrity).await
         } else {
             Err(Error::EntryNotFound(cache.to_path_buf(), key.into()))
         }
@@ -183,7 +183,7 @@ where
 /// }
 /// ```
 #[cfg(any(feature = "async-std", feature = "tokio"))]
-pub async fn read_hash<P>(cache: P, sri: &Integrity) -> Result<Vec<u8>>
+pub async fn read_hash<P>(cache: P, sri: Integrity) -> Result<Vec<u8>>
 where
     P: AsRef<Path>,
 {