1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182

//! `Handler` and supplemental components.

use futures::{Async, Poll};
use std::fmt;
use std::sync::Arc;

use error::Error;
use input::Input;
use output::{AsyncResponder, Output, Responder};

/// A trait representing handler functions.
pub trait Handler {
    /// Applies an incoming request to this handler.
    fn handle(&self, input: &mut Input) -> Handle;
}

impl<F> Handler for F
where
    F: Fn(&mut Input) -> Handle,
{
    #[inline]
    fn handle(&self, input: &mut Input) -> Handle {
        (*self)(input)
    }
}

impl<H> Handler for Arc<H>
where
    H: Handler,
{
    #[inline]
    fn handle(&self, input: &mut Input) -> Handle {
        (**self).handle(input)
    }
}

/// A type representing the return value from `Handler::handle`.
pub struct Handle(HandleKind);

#[cfg_attr(feature = "cargo-clippy", allow(large_enum_variant))]
enum HandleKind {
    Ready(Option<Result<Output, Error>>),
    Async(Box<dyn FnMut(&mut Input) -> Poll<Output, Error> + Send + 'static>),
}

#[cfg_attr(tarpaulin, skip)]
impl fmt::Debug for Handle {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.debug_struct("Handle").finish()
    }
}

impl Handle {
    #[doc(hidden)]
    pub fn ready(result: Result<Output, Error>) -> Handle {
        Handle(HandleKind::Ready(Some(result)))
    }

    #[doc(hidden)]
    pub fn wrap_async(mut x: impl AsyncResponder) -> Handle {
        Handle(HandleKind::Async(Box::new(move |input| {
            x.poll_respond_to(input)
        })))
    }

    pub(crate) fn poll_ready(&mut self, input: &mut Input) -> Poll<Output, Error> {
        match self.0 {
            HandleKind::Ready(ref mut res) => res.take().expect("this future has already polled").map(Async::Ready),
            HandleKind::Async(ref mut f) => (f)(input),
        }
    }
}

/// Create an instance of `Handler` from the provided function.
///
/// The provided handler is *synchronous*, which means that the provided handler
/// will return a result and immediately converted into an HTTP response without polling
/// the asynchronous status.
///
/// # Examples
///
/// ```
/// # use tsukuyomi::app::App;
/// # use tsukuyomi::input::Input;
/// # use tsukuyomi::handler::wrap_ready;
/// fn index(input: &mut Input) -> &'static str {
///     "Hello, Tsukuyomi.\n"
/// }
///
/// # fn main() -> tsukuyomi::AppResult<()> {
/// let app = App::builder()
///     .route(("/index.html", wrap_ready(index)))
///     .finish()?;
/// # Ok(())
/// # }
/// ```
pub fn wrap_ready<R>(f: impl Fn(&mut Input) -> R) -> impl Handler
where
    R: Responder,
{
    #[allow(missing_debug_implementations)]
    struct ReadyHandler<T>(T);

    impl<T, R> Handler for ReadyHandler<T>
    where
        T: Fn(&mut Input) -> R,
        R: Responder,
    {
        fn handle(&self, input: &mut Input) -> Handle {
            Handle::ready((self.0)(input).respond_to(input))
        }
    }

    ReadyHandler(f)
}

/// Create an instance of `Handler` from the provided function.
///
/// The provided handler is *asynchronous*, which means that the handler will
/// process some tasks by using the provided reference to `Input` and return a future for
/// processing the remaining task.
///
/// # Examples
///
/// ```
/// # use tsukuyomi::app::App;
/// # use tsukuyomi::error::Error;
/// # use tsukuyomi::input::Input;
/// # use tsukuyomi::output::AsyncResponder;
/// # use tsukuyomi::handler::wrap_async;
/// fn handler(input: &mut Input) -> impl AsyncResponder<Output = String> {
///     input.body_mut().read_all().convert_to()
/// }
///
/// # fn main() -> tsukuyomi::AppResult<()> {
/// let app = App::builder()
///     .route(("/posts", wrap_async(handler)))
///     .finish()?;
/// # Ok(())
/// # }
/// ```
///
/// ```ignore
/// # extern crate tsukuyomi;
/// # extern crate futures_await as futures;
/// # use tsukuyomi::app::App;
/// # use tsukuyomi::error::Error;
/// # use tsukuyomi::input::Input;
/// # use tsukuyomi::output::Responder;
/// # use tsukuyomi::handler::wrap_async;
/// # use futures::prelude::*;
/// #[async]
/// fn handler() -> tsukuyomi::Result<impl Responder> {
///     Ok("Hello")
/// }
///
/// # fn main() -> tsukuyomi::AppResult<()> {
/// let app = App::builder()
///     .route(("/posts", wrap_async(handler)))
///     .finish()?;
/// # Ok(())
/// # }
/// ```
pub fn wrap_async<R>(f: impl Fn(&mut Input) -> R) -> impl Handler
where
    R: AsyncResponder,
{
    #[allow(missing_debug_implementations)]
    struct AsyncHandler<T>(T);

    impl<T, R> Handler for AsyncHandler<T>
    where
        T: Fn(&mut Input) -> R,
        R: AsyncResponder,
    {
        fn handle(&self, input: &mut Input) -> Handle {
            Handle::wrap_async((self.0)(input))
        }
    }

    AsyncHandler(f)
}