From ef9bfb8981a5a51b03a7a2c704b192dc560f0457 Mon Sep 17 00:00:00 2001
From: Nikolay Kim <fafhrd91@gmail.com>
Date: Tue, 12 Mar 2019 12:53:08 -0700
Subject: [PATCH] add helpers

---
 actix-service/CHANGES.md                    |  11 ++
 actix-service/src/apply.rs                  |  28 ++++
 actix-service/src/fn_transform.rs           |  13 ++
 actix-service/src/lib.rs                    |  21 ++-
 actix-service/src/transform.rs              | 108 ++++++++++---
 actix-service/src/transform_err.rs          | 162 ++++++++++++++++++++
 actix-service/src/transform_map_init_err.rs |  94 ------------
 7 files changed, 314 insertions(+), 123 deletions(-)
 create mode 100644 actix-service/src/transform_err.rs
 delete mode 100644 actix-service/src/transform_map_init_err.rs

diff --git a/actix-service/CHANGES.md b/actix-service/CHANGES.md
index 3cf8fc4c..e8f3df6c 100644
--- a/actix-service/CHANGES.md
+++ b/actix-service/CHANGES.md
@@ -1,5 +1,16 @@
 # Changes
 
+## [0.3.4] - 2019-03-12
+
+### Added
+
+* Add `Transform::from_err()` combinator
+
+* Add `apply_fn` and `apply_fn_factory` helpers
+
+* Add `apply_transform` helper
+
+
 ## [0.3.3] - 2019-03-09
 
 ### Added
diff --git a/actix-service/src/apply.rs b/actix-service/src/apply.rs
index d5dda2d4..9719e087 100644
--- a/actix-service/src/apply.rs
+++ b/actix-service/src/apply.rs
@@ -4,6 +4,34 @@ use futures::{Async, Future, IntoFuture, Poll};
 
 use super::{IntoNewService, IntoService, NewService, Service};
 
+/// Apply tranform function to a service
+pub fn apply_fn<T, F, In, Out, U>(service: U, f: F) -> Apply<T, F, In, Out>
+where
+    T: Service,
+    F: FnMut(In, &mut T) -> Out,
+    Out: IntoFuture,
+    Out::Error: From<T::Error>,
+    U: IntoService<T>,
+{
+    Apply::new(service.into_service(), f)
+}
+
+/// Create fractory for `apply_fn` service.
+pub fn apply_fn_factory<T, F, In, Out, Cfg, U>(
+    service: U,
+    f: F,
+) -> ApplyNewService<T, F, In, Out, Cfg>
+where
+    T: NewService<Cfg>,
+    F: FnMut(In, &mut T::Service) -> Out + Clone,
+    Out: IntoFuture,
+    Out::Error: From<T::Error>,
+    U: IntoNewService<T, Cfg>,
+{
+    ApplyNewService::new(service.into_new_service(), f)
+}
+
+#[doc(hidden)]
 /// `Apply` service combinator
 pub struct Apply<T, F, In, Out>
 where
diff --git a/actix-service/src/fn_transform.rs b/actix-service/src/fn_transform.rs
index 7c3773ba..f7d708f7 100644
--- a/actix-service/src/fn_transform.rs
+++ b/actix-service/src/fn_transform.rs
@@ -5,6 +5,19 @@ use futures::IntoFuture;
 
 use crate::{Apply, IntoTransform, Service, Transform};
 
+/// Use function as transform service
+pub fn fn_transform<F, S, In, Out, Err>(
+    f: F,
+) -> impl Transform<S, Request = In, Response = Out::Item, Error = Out::Error, InitError = Err>
+where
+    S: Service,
+    F: FnMut(In, &mut S) -> Out + Clone,
+    Out: IntoFuture,
+    Out::Error: From<S::Error>,
+{
+    FnTransform::new(f)
+}
+
 pub struct FnTransform<F, S, In, Out, Err>
 where
     F: FnMut(In, &mut S) -> Out + Clone,
diff --git a/actix-service/src/lib.rs b/actix-service/src/lib.rs
index 4e46da7b..38e220af 100644
--- a/actix-service/src/lib.rs
+++ b/actix-service/src/lib.rs
@@ -21,21 +21,34 @@ mod map_err;
 mod map_init_err;
 mod then;
 mod transform;
-mod transform_map_init_err;
+mod transform_err;
+
+#[doc(hidden)]
+#[deprecated(since = "0.3.4", note = "please use `apply_fn` instead")]
+pub use self::apply::Apply;
+#[doc(hidden)]
+#[deprecated(since = "0.3.4", note = "please use `apply_fn_factory` instead")]
+pub use self::apply::ApplyNewService;
+#[doc(hidden)]
+#[deprecated(since = "0.3.4", note = "please use `fn_transform` instead")]
+pub use self::fn_transform::FnTransform;
+#[doc(hidden)]
+#[deprecated(since = "0.3.4", note = "please use `apply_transform` instead")]
+pub use self::transform::ApplyTransform;
 
 pub use self::and_then::{AndThen, AndThenNewService};
 use self::and_then_apply::AndThenTransform;
 use self::and_then_apply_fn::{AndThenApply, AndThenApplyNewService};
-pub use self::apply::{Apply, ApplyNewService};
+pub use self::apply::{apply_fn, apply_fn_factory};
 pub use self::apply_cfg::ApplyConfig;
 pub use self::fn_service::{fn_cfg_factory, fn_factory, fn_service, FnService};
-pub use self::fn_transform::FnTransform;
+pub use self::fn_transform::fn_transform;
 pub use self::from_err::{FromErr, FromErrNewService};
 pub use self::map::{Map, MapNewService};
 pub use self::map_err::{MapErr, MapErrNewService};
 pub use self::map_init_err::MapInitErr;
 pub use self::then::{Then, ThenNewService};
-pub use self::transform::{ApplyTransform, IntoTransform, Transform};
+pub use self::transform::{apply_transform, IntoTransform, Transform};
 
 /// An asynchronous function from `Request` to a `Response`.
 pub trait Service {
diff --git a/actix-service/src/transform.rs b/actix-service/src/transform.rs
index 3e8a693e..b511b67a 100644
--- a/actix-service/src/transform.rs
+++ b/actix-service/src/transform.rs
@@ -3,8 +3,8 @@ use std::sync::Arc;
 
 use futures::{Async, Future, IntoFuture, Poll};
 
-use crate::transform_map_init_err::TransformMapInitErr;
-use crate::{NewService, Service};
+use crate::transform_err::{TransformFromErr, TransformMapInitErr};
+use crate::{IntoNewService, NewService, Service};
 
 /// `Transform` service factory.
 ///
@@ -36,7 +36,7 @@ pub trait Transform<S> {
     /// Create and return a new service value asynchronously.
     fn new_transform(&self, service: S) -> Self::Future;
 
-    /// Map this service's factory init error to a different error,
+    /// Map this service's factory error to a different error,
     /// returning a new transform service factory.
     fn map_init_err<F, E>(self, f: F) -> TransformMapInitErr<Self, S, F, E>
     where
@@ -45,6 +45,32 @@ pub trait Transform<S> {
     {
         TransformMapInitErr::new(self, f)
     }
+
+    /// Map this service's init error to any error implementing `From` for
+    /// this service`s `Error`.
+    ///
+    /// Note that this function consumes the receiving transform and returns a
+    /// wrapped version of it.
+    fn from_err<E>(self) -> TransformFromErr<Self, S, E>
+    where
+        Self: Sized,
+        E: From<Self::InitError>,
+    {
+        TransformFromErr::new(self)
+    }
+
+    // /// Map this service's init error to service's init error
+    // /// if it is implementing `Into` to this service`s `InitError`.
+    // ///
+    // /// Note that this function consumes the receiving transform and returns a
+    // /// wrapped version of it.
+    // fn into_err<E>(self) -> TransformIntoErr<Self, S>
+    // where
+    //     Self: Sized,
+    //     Self::InitError: From<Self::InitError>,
+    // {
+    //     TransformFromErr::new(self)
+    // }
 }
 
 impl<T, S> Transform<S> for Rc<T>
@@ -97,33 +123,65 @@ where
     }
 }
 
-/// `Apply` transform new service
-#[derive(Clone)]
-pub struct ApplyTransform<T, A, C> {
-    a: A,
+/// Apply transform to service factory. Function returns
+/// services factory that in initialization creates
+/// service and applies transform to this service.
+pub fn apply_transform<T, S, C, F, U>(
+    t: F,
+    service: U,
+) -> impl NewService<
+    C,
+    Request = T::Request,
+    Response = T::Response,
+    Error = T::Error,
+    Service = T::Transform,
+    InitError = S::InitError,
+> + Clone
+where
+    S: NewService<C>,
+    T: Transform<S::Service, InitError = S::InitError>,
+    F: IntoTransform<T, S::Service>,
+    U: IntoNewService<S, C>,
+{
+    ApplyTransform::new(t.into_transform(), service.into_new_service())
+}
+
+/// `Apply` transform to new service
+pub struct ApplyTransform<T, S, C> {
+    s: Rc<S>,
     t: Rc<T>,
     _t: std::marker::PhantomData<C>,
 }
 
-impl<T, A, C> ApplyTransform<T, A, C>
+impl<T, S, C> ApplyTransform<T, S, C>
 where
-    A: NewService<C>,
-    T: Transform<A::Service, Error = A::Error, InitError = A::InitError>,
+    S: NewService<C>,
+    T: Transform<S::Service, InitError = S::InitError>,
 {
-    /// Create new `ApplyNewService` new service instance
-    pub fn new<F: IntoTransform<T, A::Service>>(t: F, a: A) -> Self {
+    /// Create new `ApplyTransform` new service instance
+    pub fn new<F: IntoTransform<T, S::Service>>(t: F, service: S) -> Self {
         Self {
-            a,
+            s: Rc::new(service),
             t: Rc::new(t.into_transform()),
             _t: std::marker::PhantomData,
         }
     }
 }
 
-impl<T, A, C> NewService<C> for ApplyTransform<T, A, C>
+impl<T, S, C> Clone for ApplyTransform<T, S, C> {
+    fn clone(&self) -> Self {
+        ApplyTransform {
+            s: self.s.clone(),
+            t: self.t.clone(),
+            _t: std::marker::PhantomData,
+        }
+    }
+}
+
+impl<T, S, C> NewService<C> for ApplyTransform<T, S, C>
 where
-    A: NewService<C>,
-    T: Transform<A::Service, Error = A::Error, InitError = A::InitError>,
+    S: NewService<C>,
+    T: Transform<S::Service, InitError = S::InitError>,
 {
     type Request = T::Request;
     type Response = T::Response;
@@ -131,31 +189,31 @@ where
 
     type Service = T::Transform;
     type InitError = T::InitError;
-    type Future = ApplyTransformFuture<T, A, C>;
+    type Future = ApplyTransformFuture<T, S, C>;
 
     fn new_service(&self, cfg: &C) -> Self::Future {
         ApplyTransformFuture {
             t_cell: self.t.clone(),
-            fut_a: self.a.new_service(cfg).into_future(),
+            fut_a: self.s.new_service(cfg).into_future(),
             fut_t: None,
         }
     }
 }
 
-pub struct ApplyTransformFuture<T, A, C>
+pub struct ApplyTransformFuture<T, S, C>
 where
-    A: NewService<C>,
-    T: Transform<A::Service, Error = A::Error, InitError = A::InitError>,
+    S: NewService<C>,
+    T: Transform<S::Service, InitError = S::InitError>,
 {
-    fut_a: A::Future,
+    fut_a: S::Future,
     fut_t: Option<<T::Future as IntoFuture>::Future>,
     t_cell: Rc<T>,
 }
 
-impl<T, A, C> Future for ApplyTransformFuture<T, A, C>
+impl<T, S, C> Future for ApplyTransformFuture<T, S, C>
 where
-    A: NewService<C>,
-    T: Transform<A::Service, Error = A::Error, InitError = A::InitError>,
+    S: NewService<C>,
+    T: Transform<S::Service, InitError = S::InitError>,
 {
     type Item = T::Transform;
     type Error = T::InitError;
diff --git a/actix-service/src/transform_err.rs b/actix-service/src/transform_err.rs
new file mode 100644
index 00000000..dcc3c245
--- /dev/null
+++ b/actix-service/src/transform_err.rs
@@ -0,0 +1,162 @@
+use std::marker::PhantomData;
+
+use futures::{Future, Poll};
+
+use super::Transform;
+
+/// Transform for the `map_err` combinator, changing the type of a new
+/// transform's init error.
+///
+/// This is created by the `Transform::map_err` method.
+pub struct TransformMapInitErr<T, S, F, E> {
+    t: T,
+    f: F,
+    e: PhantomData<(S, E)>,
+}
+
+impl<T, S, F, E> TransformMapInitErr<T, S, F, E> {
+    /// Create new `TransformMapErr` new transform instance
+    pub fn new(t: T, f: F) -> Self
+    where
+        T: Transform<S>,
+        F: Fn(T::InitError) -> E,
+    {
+        Self {
+            t,
+            f,
+            e: PhantomData,
+        }
+    }
+}
+
+impl<T, S, F, E> Clone for TransformMapInitErr<T, S, F, E>
+where
+    T: Clone,
+    F: Clone,
+{
+    fn clone(&self) -> Self {
+        Self {
+            t: self.t.clone(),
+            f: self.f.clone(),
+            e: PhantomData,
+        }
+    }
+}
+
+impl<T, S, F, E> Transform<S> for TransformMapInitErr<T, S, F, E>
+where
+    T: Transform<S>,
+    F: Fn(T::InitError) -> E + Clone,
+{
+    type Request = T::Request;
+    type Response = T::Response;
+    type Error = T::Error;
+    type Transform = T::Transform;
+
+    type InitError = E;
+    type Future = TransformMapInitErrFuture<T, S, F, E>;
+
+    fn new_transform(&self, service: S) -> Self::Future {
+        TransformMapInitErrFuture {
+            fut: self.t.new_transform(service),
+            f: self.f.clone(),
+        }
+    }
+}
+
+pub struct TransformMapInitErrFuture<T, S, F, E>
+where
+    T: Transform<S>,
+    F: Fn(T::InitError) -> E,
+{
+    fut: T::Future,
+    f: F,
+}
+
+impl<T, S, F, E> Future for TransformMapInitErrFuture<T, S, F, E>
+where
+    T: Transform<S>,
+    F: Fn(T::InitError) -> E + Clone,
+{
+    type Item = T::Transform;
+    type Error = E;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        self.fut.poll().map_err(&self.f)
+    }
+}
+
+/// Transform for the `from_err` combinator, changing the type of a new
+/// transform's init error.
+///
+/// This is created by the `Transform::from_err` method.
+pub struct TransformFromErr<T, S, E> {
+    t: T,
+    e: PhantomData<(S, E)>,
+}
+
+impl<T, S, E> TransformFromErr<T, S, E>
+where
+    T: Transform<S>,
+    E: From<T::InitError>,
+{
+    /// Create new `TransformFromErr` new transform instance
+    pub fn new(t: T) -> Self {
+        Self { t, e: PhantomData }
+    }
+}
+
+impl<T, S, E> Clone for TransformFromErr<T, S, E>
+where
+    T: Clone,
+{
+    fn clone(&self) -> Self {
+        Self {
+            t: self.t.clone(),
+            e: PhantomData,
+        }
+    }
+}
+
+impl<T, S, E> Transform<S> for TransformFromErr<T, S, E>
+where
+    T: Transform<S>,
+    E: From<T::InitError>,
+{
+    type Request = T::Request;
+    type Response = T::Response;
+    type Error = T::Error;
+    type Transform = T::Transform;
+
+    type InitError = E;
+    type Future = TransformFromErrFuture<T, S, E>;
+
+    fn new_transform(&self, service: S) -> Self::Future {
+        TransformFromErrFuture {
+            fut: self.t.new_transform(service),
+            _t: PhantomData,
+        }
+    }
+}
+
+pub struct TransformFromErrFuture<T, S, E>
+where
+    T: Transform<S>,
+    E: From<T::InitError>,
+{
+    fut: T::Future,
+    _t: PhantomData<E>,
+}
+
+impl<T, S, E> Future for TransformFromErrFuture<T, S, E>
+where
+    T: Transform<S>,
+    E: From<T::InitError>,
+{
+    type Item = T::Transform;
+    type Error = E;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        self.fut.poll().map_err(E::from)
+    }
+}
diff --git a/actix-service/src/transform_map_init_err.rs b/actix-service/src/transform_map_init_err.rs
deleted file mode 100644
index 0b0dd9b9..00000000
--- a/actix-service/src/transform_map_init_err.rs
+++ /dev/null
@@ -1,94 +0,0 @@
-use std::marker::PhantomData;
-
-use futures::{Future, Poll};
-
-use super::Transform;
-
-/// NewTransform for the `map_init_err` combinator, changing the type of a new
-/// transform's error.
-///
-/// This is created by the `NewTransform::map_init_err` method.
-pub struct TransformMapInitErr<T, S, F, E> {
-    t: T,
-    f: F,
-    e: PhantomData<(S, E)>,
-}
-
-impl<T, S, F, E> TransformMapInitErr<T, S, F, E> {
-    /// Create new `MapInitErr` new transform instance
-    pub fn new(t: T, f: F) -> Self
-    where
-        T: Transform<S>,
-        F: Fn(T::InitError) -> E,
-    {
-        Self {
-            t,
-            f,
-            e: PhantomData,
-        }
-    }
-}
-
-impl<T, S, F, E> Clone for TransformMapInitErr<T, S, F, E>
-where
-    T: Clone,
-    F: Clone,
-{
-    fn clone(&self) -> Self {
-        Self {
-            t: self.t.clone(),
-            f: self.f.clone(),
-            e: PhantomData,
-        }
-    }
-}
-
-impl<T, S, F, E> Transform<S> for TransformMapInitErr<T, S, F, E>
-where
-    T: Transform<S>,
-    F: Fn(T::InitError) -> E + Clone,
-{
-    type Request = T::Request;
-    type Response = T::Response;
-    type Error = T::Error;
-    type Transform = T::Transform;
-
-    type InitError = E;
-    type Future = TransformMapInitErrFuture<T, S, F, E>;
-
-    fn new_transform(&self, service: S) -> Self::Future {
-        TransformMapInitErrFuture::new(self.t.new_transform(service), self.f.clone())
-    }
-}
-
-pub struct TransformMapInitErrFuture<T, S, F, E>
-where
-    T: Transform<S>,
-    F: Fn(T::InitError) -> E,
-{
-    fut: T::Future,
-    f: F,
-}
-
-impl<T, S, F, E> TransformMapInitErrFuture<T, S, F, E>
-where
-    T: Transform<S>,
-    F: Fn(T::InitError) -> E,
-{
-    fn new(fut: T::Future, f: F) -> Self {
-        TransformMapInitErrFuture { f, fut }
-    }
-}
-
-impl<T, S, F, E> Future for TransformMapInitErrFuture<T, S, F, E>
-where
-    T: Transform<S>,
-    F: Fn(T::InitError) -> E + Clone,
-{
-    type Item = T::Transform;
-    type Error = E;
-
-    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-        self.fut.poll().map_err(&self.f)
-    }
-}