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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
//! # Wasmtime's WASI HTTP Implementation
//!
//! This crate is Wasmtime's host implementation of the `wasi:http` package as
//! part of WASIp2. This crate's implementation is primarily built on top of
//! [`hyper`] and [`tokio`].
//!
//! # WASI HTTP Interfaces
//!
//! This crate contains implementations of the following interfaces:
//!
//! * [`wasi:http/incoming-handler`]
//! * [`wasi:http/outgoing-handler`]
//! * [`wasi:http/types`]
//!
//! The crate also contains an implementation of the [`wasi:http/proxy`] world.
//!
//! [`wasi:http/proxy`]: crate::bindings::Proxy
//! [`wasi:http/outgoing-handler`]: crate::bindings::http::outgoing_handler::Host
//! [`wasi:http/types`]: crate::bindings::http::types::Host
//! [`wasi:http/incoming-handler`]: crate::bindings::exports::wasi::http::incoming_handler::Guest
//!
//! This crate is very similar to [`wasmtime-wasi`] in the it uses the
//! `bindgen!` macro in Wasmtime to generate bindings to interfaces. Bindings
//! are located in the [`bindings`] module.
//!
//! # The `WasiHttpView` trait
//!
//! All `bindgen!`-generated `Host` traits are implemented in terms of a
//! [`WasiHttpView`] trait which provides basic access to [`WasiHttpCtx`],
//! configuration for WASI HTTP, and a [`wasmtime_wasi::ResourceTable`], the
//! state for all host-defined component model resources.
//!
//! The [`WasiHttpView`] trait additionally offers a few other configuration
//! methods such as [`WasiHttpView::send_request`] to customize how outgoing
//! HTTP requests are handled.
//!
//! # Async and Sync
//!
//! There are both asynchronous and synchronous bindings in this crate. For
//! example [`add_to_linker_async`] is for asynchronous embedders and
//! [`add_to_linker_sync`] is for synchronous embedders. Note that under the
//! hood both versions are implemented with `async` on top of [`tokio`].
//!
//! # Examples
//!
//! Usage of this crate is done through a few steps to get everything hooked up:
//!
//! 1. First implement [`WasiHttpView`] for your type which is the `T` in
//!    [`wasmtime::Store<T>`].
//! 2. Add WASI HTTP interfaces to a [`wasmtime::component::Linker<T>`]. There
//!    are a few options of how to do this:
//!    * Use [`add_to_linker_async`] to bundle all interfaces in
//!      `wasi:http/proxy` together
//!    * Use [`add_only_http_to_linker_async`] to add only HTTP interfaces but
//!      no others. This is useful when working with
//!      [`wasmtime_wasi::add_to_linker_async`] for example.
//!    * Add individual interfaces such as with the
//!      [`bindings::http::outgoing_handler::add_to_linker_get_host`] function.
//! 3. Use [`ProxyPre`](bindings::ProxyPre) to pre-instantiate a component
//!    before serving requests.
//! 4. When serving requests use
//!    [`ProxyPre::instantiate_async`](bindings::ProxyPre::instantiate_async)
//!    to create instances and handle HTTP requests.
//!
//! A standalone example of doing all this looks like:
//!
//! ```no_run
//! use anyhow::bail;
//! use hyper::server::conn::http1;
//! use std::sync::Arc;
//! use tokio::net::TcpListener;
//! use wasmtime::component::{Component, Linker, ResourceTable};
//! use wasmtime::{Config, Engine, Result, Store};
//! use wasmtime_wasi::{WasiCtx, WasiCtxBuilder, WasiView};
//! use wasmtime_wasi_http::bindings::ProxyPre;
//! use wasmtime_wasi_http::bindings::http::types::Scheme;
//! use wasmtime_wasi_http::body::HyperOutgoingBody;
//! use wasmtime_wasi_http::io::TokioIo;
//! use wasmtime_wasi_http::{WasiHttpCtx, WasiHttpView};
//!
//! #[tokio::main]
//! async fn main() -> Result<()> {
//!     let component = std::env::args().nth(1).unwrap();
//!
//!     // Prepare the `Engine` for Wasmtime
//!     let mut config = Config::new();
//!     config.async_support(true);
//!     let engine = Engine::new(&config)?;
//!
//!     // Compile the component on the command line to machine code
//!     let component = Component::from_file(&engine, &component)?;
//!
//!     // Prepare the `ProxyPre` which is a pre-instantiated version of the
//!     // component that we have. This will make per-request instantiation
//!     // much quicker.
//!     let mut linker = Linker::new(&engine);
//!     wasmtime_wasi_http::add_to_linker_async(&mut linker)?;
//!     let pre = ProxyPre::new(linker.instantiate_pre(&component)?)?;
//!
//!     // Prepare our server state and start listening for connections.
//!     let server = Arc::new(MyServer { pre });
//!     let listener = TcpListener::bind("127.0.0.1:8000").await?;
//!     println!("Listening on {}", listener.local_addr()?);
//!
//!     loop {
//!         // Accept a TCP connection and serve all of its requests in a separate
//!         // tokio task. Note that for now this only works with HTTP/1.1.
//!         let (client, addr) = listener.accept().await?;
//!         println!("serving new client from {addr}");
//!
//!         let server = server.clone();
//!         tokio::task::spawn(async move {
//!             if let Err(e) = http1::Builder::new()
//!                 .keep_alive(true)
//!                 .serve_connection(
//!                     TokioIo::new(client),
//!                     hyper::service::service_fn(move |req| {
//!                         let server = server.clone();
//!                         async move { server.handle_request(req).await }
//!                     }),
//!                 )
//!                 .await
//!             {
//!                 eprintln!("error serving client[{addr}]: {e:?}");
//!             }
//!         });
//!     }
//! }
//!
//! struct MyServer {
//!     pre: ProxyPre<MyClientState>,
//! }
//!
//! impl MyServer {
//!     async fn handle_request(
//!         &self,
//!         req: hyper::Request<hyper::body::Incoming>,
//!     ) -> Result<hyper::Response<HyperOutgoingBody>> {
//!         // Create per-http-request state within a `Store` and prepare the
//!         // initial resources  passed to the `handle` function.
//!         let mut store = Store::new(
//!             self.pre.engine(),
//!             MyClientState {
//!                 table: ResourceTable::new(),
//!                 wasi: WasiCtxBuilder::new().inherit_stdio().build(),
//!                 http: WasiHttpCtx::new(),
//!             },
//!         );
//!         let (sender, receiver) = tokio::sync::oneshot::channel();
//!         let req = store.data_mut().new_incoming_request(Scheme::Http, req)?;
//!         let out = store.data_mut().new_response_outparam(sender)?;
//!         let pre = self.pre.clone();
//!
//!         // Run the http request itself in a separate task so the task can
//!         // optionally continue to execute beyond after the initial
//!         // headers/response code are sent.
//!         let task = tokio::task::spawn(async move {
//!             let proxy = pre.instantiate_async(&mut store).await?;
//!
//!             if let Err(e) = proxy
//!                 .wasi_http_incoming_handler()
//!                 .call_handle(store, req, out)
//!                 .await
//!             {
//!                 return Err(e);
//!             }
//!
//!             Ok(())
//!         });
//!
//!         match receiver.await {
//!             // If the client calls `response-outparam::set` then one of these
//!             // methods will be called.
//!             Ok(Ok(resp)) => Ok(resp),
//!             Ok(Err(e)) => Err(e.into()),
//!
//!             // Otherwise the `sender` will get dropped along with the `Store`
//!             // meaning that the oneshot will get disconnected and here we can
//!             // inspect the `task` result to see what happened
//!             Err(_) => {
//!                 let e = match task.await {
//!                     Ok(r) => r.unwrap_err(),
//!                     Err(e) => e.into(),
//!                 };
//!                 bail!("guest never invoked `response-outparam::set` method: {e:?}")
//!             }
//!         }
//!     }
//! }
//!
//! struct MyClientState {
//!     wasi: WasiCtx,
//!     http: WasiHttpCtx,
//!     table: ResourceTable,
//! }
//!
//! impl WasiView for MyClientState {
//!     fn ctx(&mut self) -> &mut WasiCtx {
//!         &mut self.wasi
//!     }
//!     fn table(&mut self) -> &mut ResourceTable {
//!         &mut self.table
//!     }
//! }
//!
//! impl WasiHttpView for MyClientState {
//!     fn ctx(&mut self) -> &mut WasiHttpCtx {
//!         &mut self.http
//!     }
//!     fn table(&mut self) -> &mut ResourceTable {
//!         &mut self.table
//!     }
//! }
//! ```

#![deny(missing_docs)]
#![doc(test(attr(deny(warnings))))]
#![doc(test(attr(allow(dead_code, unused_variables, unused_mut))))]

mod error;
mod http_impl;
mod types_impl;

pub mod body;
pub mod io;
pub mod types;

pub mod bindings;

pub use crate::error::{
    http_request_error, hyper_request_error, hyper_response_error, HttpError, HttpResult,
};
#[doc(inline)]
pub use crate::types::{WasiHttpCtx, WasiHttpImpl, WasiHttpView};

/// Add all of the `wasi:http/proxy` world's interfaces to a [`wasmtime::component::Linker`].
///
/// This function will add the `async` variant of all interfaces into the
/// `Linker` provided. By `async` this means that this function is only
/// compatible with [`Config::async_support(true)`][async]. For embeddings with
/// async support disabled see [`add_to_linker_sync`] instead.
///
/// [async]: wasmtime::Config::async_support
///
/// # Example
///
/// ```
/// use wasmtime::{Engine, Result, Config};
/// use wasmtime::component::{ResourceTable, Linker};
/// use wasmtime_wasi::{WasiCtx, WasiView};
/// use wasmtime_wasi_http::{WasiHttpCtx, WasiHttpView};
///
/// fn main() -> Result<()> {
///     let mut config = Config::new();
///     config.async_support(true);
///     let engine = Engine::new(&config)?;
///
///     let mut linker = Linker::<MyState>::new(&engine);
///     wasmtime_wasi_http::add_to_linker_async(&mut linker)?;
///     // ... add any further functionality to `linker` if desired ...
///
///     Ok(())
/// }
///
/// struct MyState {
///     ctx: WasiCtx,
///     http_ctx: WasiHttpCtx,
///     table: ResourceTable,
/// }
///
/// impl WasiHttpView for MyState {
///     fn ctx(&mut self) -> &mut WasiHttpCtx { &mut self.http_ctx }
///     fn table(&mut self) -> &mut ResourceTable { &mut self.table }
/// }
/// impl WasiView for MyState {
///     fn ctx(&mut self) -> &mut WasiCtx { &mut self.ctx }
///     fn table(&mut self) -> &mut ResourceTable { &mut self.table }
/// }
/// ```
pub fn add_to_linker_async<T>(l: &mut wasmtime::component::Linker<T>) -> anyhow::Result<()>
where
    T: WasiHttpView + wasmtime_wasi::WasiView,
{
    let closure = type_annotate_wasi::<T, _>(|t| wasmtime_wasi::WasiImpl(t));
    wasmtime_wasi::bindings::clocks::wall_clock::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::clocks::monotonic_clock::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::io::poll::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::io::error::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::io::streams::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::cli::stdin::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::cli::stdout::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::cli::stderr::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::random::random::add_to_linker_get_host(l, closure)?;

    add_only_http_to_linker_async(l)
}

// NB: workaround some rustc inference - a future refactoring may make this
// obsolete.
fn type_annotate_http<T, F>(val: F) -> F
where
    F: Fn(&mut T) -> WasiHttpImpl<&mut T>,
{
    val
}
fn type_annotate_wasi<T, F>(val: F) -> F
where
    F: Fn(&mut T) -> wasmtime_wasi::WasiImpl<&mut T>,
{
    val
}

/// A slimmed down version of [`add_to_linker_async`] which only adds
/// `wasi:http` interfaces to the linker.
///
/// This is useful when using [`wasmtime_wasi::add_to_linker_async`] for
/// example to avoid re-adding the same interfaces twice.
pub fn add_only_http_to_linker_async<T>(
    l: &mut wasmtime::component::Linker<T>,
) -> anyhow::Result<()>
where
    T: WasiHttpView,
{
    let closure = type_annotate_http::<T, _>(|t| WasiHttpImpl(t));
    crate::bindings::http::outgoing_handler::add_to_linker_get_host(l, closure)?;
    crate::bindings::http::types::add_to_linker_get_host(l, closure)?;

    Ok(())
}

/// Add all of the `wasi:http/proxy` world's interfaces to a [`wasmtime::component::Linker`].
///
/// This function will add the `sync` variant of all interfaces into the
/// `Linker` provided. For embeddings with async support see
/// [`add_to_linker_async`] instead.
///
/// # Example
///
/// ```
/// use wasmtime::{Engine, Result, Config};
/// use wasmtime::component::{ResourceTable, Linker};
/// use wasmtime_wasi::{WasiCtx, WasiView};
/// use wasmtime_wasi_http::{WasiHttpCtx, WasiHttpView};
///
/// fn main() -> Result<()> {
///     let config = Config::default();
///     let engine = Engine::new(&config)?;
///
///     let mut linker = Linker::<MyState>::new(&engine);
///     wasmtime_wasi_http::add_to_linker_sync(&mut linker)?;
///     // ... add any further functionality to `linker` if desired ...
///
///     Ok(())
/// }
///
/// struct MyState {
///     ctx: WasiCtx,
///     http_ctx: WasiHttpCtx,
///     table: ResourceTable,
/// }
///
/// impl WasiHttpView for MyState {
///     fn ctx(&mut self) -> &mut WasiHttpCtx { &mut self.http_ctx }
///     fn table(&mut self) -> &mut ResourceTable { &mut self.table }
/// }
/// impl WasiView for MyState {
///     fn ctx(&mut self) -> &mut WasiCtx { &mut self.ctx }
///     fn table(&mut self) -> &mut ResourceTable { &mut self.table }
/// }
/// ```
pub fn add_to_linker_sync<T>(l: &mut wasmtime::component::Linker<T>) -> anyhow::Result<()>
where
    T: WasiHttpView + wasmtime_wasi::WasiView,
{
    let closure = type_annotate_wasi::<T, _>(|t| wasmtime_wasi::WasiImpl(t));

    wasmtime_wasi::bindings::clocks::wall_clock::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::clocks::monotonic_clock::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::sync::io::poll::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::sync::io::streams::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::io::error::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::cli::stdin::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::cli::stdout::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::cli::stderr::add_to_linker_get_host(l, closure)?;
    wasmtime_wasi::bindings::random::random::add_to_linker_get_host(l, closure)?;

    add_only_http_to_linker_sync(l)?;

    Ok(())
}

/// A slimmed down version of [`add_to_linker_sync`] which only adds
/// `wasi:http` interfaces to the linker.
///
/// This is useful when using [`wasmtime_wasi::add_to_linker_sync`] for
/// example to avoid re-adding the same interfaces twice.
pub fn add_only_http_to_linker_sync<T>(l: &mut wasmtime::component::Linker<T>) -> anyhow::Result<()>
where
    T: WasiHttpView,
{
    let closure = type_annotate_http::<T, _>(|t| WasiHttpImpl(t));

    crate::bindings::http::outgoing_handler::add_to_linker_get_host(l, closure)?;
    crate::bindings::http::types::add_to_linker_get_host(l, closure)?;

    Ok(())
}