From 68d3f6c22e1a78c0a048ea2fd6ccd1565097cffa Mon Sep 17 00:00:00 2001
From: David Barsky <me@davidbarsky.com>
Date: Tue, 15 Jan 2019 15:05:14 -0500
Subject: [PATCH] Use `tokio::timer` instead of `tokio_timer`; use Kind pattern
 (#141)

---
 tower-timeout/src/lib.rs | 118 ++++++++++++++++++++++++++++++++-------
 1 file changed, 98 insertions(+), 20 deletions(-)

diff --git a/tower-timeout/src/lib.rs b/tower-timeout/src/lib.rs
index ce7528c..9cf49b7 100644
--- a/tower-timeout/src/lib.rs
+++ b/tower-timeout/src/lib.rs
@@ -3,13 +3,17 @@
 //! If the response does not complete within the specified timeout, the response
 //! will be aborted.
 
+#![doc(html_root_url = "https://docs.rs/tower-timeout/0.1.0")]
+#![deny(missing_debug_implementations, missing_docs)]
+#![cfg_attr(test, deny(warnings))]
+
 extern crate futures;
 extern crate tower_service;
 extern crate tokio_timer;
 
 use futures::{Future, Poll, Async};
 use tower_service::Service;
-use tokio_timer::{clock, Delay};
+use tokio_timer::{clock, Delay, Error as TimerError};
 
 use std::{error, fmt};
 use std::time::Duration;
@@ -23,12 +27,19 @@ pub struct Timeout<T> {
 
 /// Errors produced by `Timeout`.
 #[derive(Debug)]
-pub enum Error<T> {
-    /// The inner service produced an error
+pub struct Error<T>(Kind<T>);
+
+/// Timeout error variants
+#[derive(Debug)]
+enum Kind<T> {
+    /// Inner value returned an error
     Inner(T),
 
-    /// The request did not complete within the specified timeout.
-    Timeout,
+    /// The timeout elapsed.
+    Elapsed,
+
+    /// Timer returned an error.
+    Timer(TimerError),
 }
 
 /// `Timeout` response future
@@ -41,6 +52,7 @@ pub struct ResponseFuture<T> {
 // ===== impl Timeout =====
 
 impl<T> Timeout<T> {
+    /// Creates a new Timeout
     pub fn new(inner: T, timeout: Duration) -> Self {
         Timeout {
             inner,
@@ -59,7 +71,9 @@ where
 
     fn poll_ready(&mut self) -> Poll<(), Self::Error> {
         self.inner.poll_ready()
-            .map_err(Error::Inner)
+            .map_err(|e| {
+                Error(Kind::Inner(e))
+            })
     }
 
     fn call(&mut self, request: Request) -> Self::Future {
@@ -83,19 +97,18 @@ where T: Future,
         match self.response.poll() {
             Ok(Async::Ready(v)) => return Ok(Async::Ready(v)),
             Ok(Async::NotReady) => {}
-            Err(e) => return Err(Error::Inner(e)),
+            Err(e) => return Err(Error(Kind::Inner(e))),
         }
 
         // Now check the sleep
         match self.sleep.poll() {
             Ok(Async::NotReady) => Ok(Async::NotReady),
-            Ok(Async::Ready(_)) => Err(Error::Timeout),
-            Err(_) => Err(Error::Timeout),
+            Ok(Async::Ready(_)) => Err(Error(Kind::Elapsed)),
+            Err(e) => Err(Error(Kind::Timer(e))),
         }
     }
 }
 
-
 // ===== impl Error =====
 
 impl<T> fmt::Display for Error<T>
@@ -103,30 +116,95 @@ where
     T: fmt::Display,
 {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            Error::Inner(ref why) => fmt::Display::fmt(why, f),
-            Error::Timeout => f.pad("request timed out"),
+        match self.0 {
+            Kind::Inner(ref why) => fmt::Display::fmt(why, f),
+            Kind::Elapsed => f.pad("request timed out"),
+            Kind::Timer(ref why) => fmt::Display::fmt(why, f),
         }
     }
 }
 
 impl<T> error::Error for Error<T>
 where
-    T: error::Error,
+    T: error::Error + 'static,
 {
-    fn cause(&self) -> Option<&error::Error> {
-        if let Error::Inner(ref why) = *self {
+    fn description(&self) -> &str {
+        match self.0 {
+            Kind::Inner(ref e) => e.description(),
+            Kind::Elapsed => "request timed out",
+            Kind::Timer(ref e) => e.description(),
+        }
+    }
+
+    fn source(&self) -> Option<&(error::Error + 'static)> {
+        let kind = &self.0;
+        if let Kind::Inner(ref why) = kind {
             Some(why)
         } else {
             None
         }
     }
+}
 
-    fn description(&self) -> &str {
-        match *self {
-            Error::Inner(_) => "inner service error",
-            Error::Timeout => "request timed out",
+// ===== impl Error =====
+
+impl<T> Error<T> {
+    /// Create a new `Error` representing the inner value completing with `Err`.
+    pub fn inner(err: T) -> Error<T> {
+        Error(Kind::Inner(err))
+    }
+
+    /// Returns `true` if the error was caused by the inner value completing
+    /// with `Err`.
+    pub fn is_inner(&self) -> bool {
+        match self.0 {
+            Kind::Inner(_) => true,
+            _ => false,
         }
     }
 
+    /// Consumes `self`, returning the inner future error.
+    pub fn into_inner(self) -> Option<T> {
+        match self.0 {
+            Kind::Inner(err) => Some(err),
+            _ => None,
+        }
+    }
+
+    /// Create a new `Error` representing the inner value not completing before
+    /// the deadline is reached.
+    pub fn elapsed() -> Error<T> {
+        Error(Kind::Elapsed)
+    }
+
+    /// Returns `true` if the error was caused by the inner value not completing
+    /// before the deadline is reached.
+    pub fn is_elapsed(&self) -> bool {
+        match self.0 {
+            Kind::Elapsed => true,
+            _ => false,
+        }
+    }
+
+    /// Creates a new `Error` representing an error encountered by the timer
+    /// implementation
+    pub fn timer(err: TimerError) -> Error<T> {
+        Error(Kind::Timer(err))
+    }
+
+    /// Returns `true` if the error was caused by the timer.
+    pub fn is_timer(&self) -> bool {
+        match self.0 {
+            Kind::Timer(_) => true,
+            _ => false,
+        }
+    }
+
+    /// Consumes `self`, returning the error raised by the timer implementation.
+    pub fn into_timer(self) -> Option<TimerError> {
+        match self.0 {
+            Kind::Timer(err) => Some(err),
+            _ => None,
+        }
+    }
 }