Basic BinaryCacheStore implementation using async Rust

nix-rust/src/error.rs

@@ -1,6 +1,10 @@
 #[derive(Debug)]
 pub enum Error {
+    InvalidPath(crate::store::StorePath),
+    BadStorePath(std::path::PathBuf),
+    BadNarInfo,
     IOError(std::io::Error),
+    HttpError(reqwest::Error),
     Misc(String),
     Foreign(CppException),
 }
@@ -11,12 +15,24 @@ impl From<std::io::Error> for Error {
     }
 }
 
+impl From<reqwest::Error> for Error {
+    fn from(err: reqwest::Error) -> Self {
+        Error::HttpError(err)
+    }
+}
+
 impl From<Error> for CppException {
     fn from(err: Error) -> Self {
         match err {
+            Error::InvalidPath(_) => unsafe { make_error("invalid path") }, // FIXME
+            Error::BadNarInfo => unsafe { make_error(".narinfo file is corrupt") }, // FIXME
+            Error::BadStorePath(path) => unsafe {
+                make_error(&format!("path '{}' is not a store path", path.display()))
+            }, // FIXME
+            Error::IOError(err) => unsafe { make_error(&err.to_string()) },
+            Error::HttpError(err) => unsafe { make_error(&err.to_string()) },
             Error::Foreign(ex) => ex,
             Error::Misc(s) => unsafe { make_error(&s) },
-            Error::IOError(err) => unsafe { make_error(&err.to_string()) },
         }
     }
 }