move shared fail struct into own crate

Cargo.lock

@@ -670,6 +670,13 @@ dependencies = [
  "serde 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "shared-failure"
+version = "0.1.0"
+dependencies = [
+ "failure 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "shiny-robots"
 version = "0.1.0"
@@ -690,6 +697,7 @@ dependencies = [
  "serde 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "shared-failure 0.1.0",
  "slog 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "slog-json 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-core 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -28,5 +28,9 @@ toml = "0.4.5"
 version = "0.2.0"
 path = "libs/badge"
 
+[dependencies.shared-failure]
+version = "0.1.0"
+path = "libs/shared-failure"
+
 [build-dependencies]
 sass-rs = "0.2.1"

libs/shared-failure/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "shared-failure"
+version = "0.1.0"
+authors = ["Sam Rijs <srijs@airpost.net>"]
+
+[dependencies]
+failure = "0.1.1"

libs/shared-failure/src/lib.rs

@@ -0,0 +1,37 @@
+extern crate failure;
+
+use std::fmt::{Display, Formatter, Result as FmtResult};
+use std::sync::Arc;
+
+use failure::{Backtrace, Error, Fail};
+
+#[derive(Clone, Debug)]
+pub struct SharedFailure(Arc<Error>);
+
+impl SharedFailure {
+    pub fn downcast_ref<T: Fail>(&self) -> Option<&T> {
+        self.0.downcast_ref()
+    }
+}
+
+impl Fail for SharedFailure {
+    fn cause(&self) -> Option<&Fail> {
+        Some(self.0.cause())
+    }
+
+    fn backtrace(&self) -> Option<&Backtrace> {
+        Some(self.0.backtrace())
+    }
+}
+
+impl Display for SharedFailure {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        self.0.fmt(f)
+    }
+}
+
+impl From<Error> for SharedFailure {
+    fn from(err: Error) -> SharedFailure {
+        SharedFailure(Arc::new(err))
+    }
+}

src/main.rs

@@ -18,6 +18,7 @@ extern crate semver;
 #[macro_use] extern crate serde_derive;
 extern crate serde;
 extern crate serde_json;
+extern crate shared_failure;
 #[macro_use] extern crate slog;
 extern crate slog_json;
 extern crate tokio_core;

src/utils/cache.rs

@@ -1,13 +1,14 @@
-use std::fmt::{Debug, Display, Formatter, Result as FmtResult};
+use std::fmt::{Debug, Formatter, Result as FmtResult};
 use std::hash::Hash;
 use std::time::{Duration, Instant};
 use std::ops::Deref;
 use std::sync::Mutex;
 
-use failure::{Error, Fail};
+use failure::Error;
 use futures::{Future, Poll};
-use futures::future::{Shared, SharedError, SharedItem};
+use futures::future::{FromErr, Shared, SharedItem};
 use lru_cache::LruCache;
+use shared_failure::SharedFailure;
 use tokio_service::Service;
 
 pub struct Cache<S>
@@ -16,7 +17,7 @@ pub struct Cache<S>
 {
     inner: S,
     duration: Duration,
-    cache: Mutex<LruCache<S::Request, (Instant, Shared<S::Future>)>>
+    cache: Mutex<LruCache<S::Request, (Instant, Shared<FromErr<S::Future, SharedFailure>>)>>
 }
 
 impl<S> Debug for Cache<S>
@@ -50,7 +51,7 @@ impl<S> Service for Cache<S>
 {
     type Request = S::Request;
     type Response = CachedItem<S::Response>;
-    type Error = CachedError;
+    type Error = SharedFailure;
     type Future = Cached<S::Future>;
 
     fn call(&self, req: Self::Request) -> Self::Future {
@@ -63,18 +64,17 @@ impl<S> Service for Cache<S>
                 }
             }
         }
-        let shared_future = self.inner.call(req.clone()).shared();
+        let shared_future = self.inner.call(req.clone()).from_err().shared();
         cache.insert(req, (now + self.duration, shared_future.clone()));
         Cached(shared_future)
     }
 }
 
-pub struct Cached<F: Future>(Shared<F>);
+pub struct Cached<F: Future<Error=Error>>(Shared<FromErr<F, SharedFailure>>);
 
 impl<F> Debug for Cached<F>
-    where F: Future + Debug,
-          F::Item: Debug,
-          F::Error: Debug
+    where F: Future<Error=Error> + Debug,
+          F::Item: Debug
 {
     fn fmt(&self, fmt: &mut Formatter) -> FmtResult {
         self.0.fmt(fmt)
@@ -83,11 +83,11 @@ impl<F> Debug for Cached<F>
 
 impl<F: Future<Error=Error>> Future for Cached<F> {
     type Item = CachedItem<F::Item>;
-    type Error = CachedError;
+    type Error = SharedFailure;
 
     fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
         self.0.poll()
-            .map_err(CachedError)
+            .map_err(|err| (*err).clone())
             .map(|async| async.map(CachedItem))
     }
 }
@@ -102,26 +102,3 @@ impl<T> Deref for CachedItem<T> {
         &self.0.deref()
     }
 }
-
-#[derive(Debug)]
-pub struct CachedError(SharedError<Error>);
-
-impl Fail for CachedError {
-    fn cause(&self) -> Option<&Fail> {
-        Some(self.0.cause())
-    }
-
-    fn backtrace(&self) -> Option<&::failure::Backtrace> {
-        Some(self.0.backtrace())
-    }
-
-    fn causes(&self) -> ::failure::Causes {
-        self.0.causes()
-    }
-}
-
-impl Display for CachedError {
-    fn fmt(&self, f: &mut Formatter) -> FmtResult {
-        Display::fmt(&self.0, f)
-    }
-}