ruwuma/src/api/mod.rs

329 lines
10 KiB
Rust

use quote::{ToTokens, Tokens};
use syn::{Field, MetaItem};
mod metadata;
mod request;
mod response;
use parse::Entry;
use self::metadata::Metadata;
use self::request::Request;
use self::response::Response;
pub fn strip_serde_attrs(field: &Field) -> Field {
let mut field = field.clone();
field.attrs = field.attrs.into_iter().filter(|attr| {
let (attr_ident, _) = match attr.value {
MetaItem::List(ref attr_ident, _) => {
(attr_ident, ())
}
_ => return true,
};
if attr_ident != "serde" {
return true;
}
false
}).collect();
field
}
#[derive(Debug)]
pub struct Api {
metadata: Metadata,
request: Request,
response: Response,
}
impl ToTokens for Api {
fn to_tokens(&self, tokens: &mut Tokens) {
let description = &self.metadata.description;
let method = &self.metadata.method;
let name = &self.metadata.name;
let path = &self.metadata.path;
let rate_limited = &self.metadata.rate_limited;
let requires_authentication = &self.metadata.requires_authentication;
let request_types = {
let mut tokens = Tokens::new();
self.request.to_tokens(&mut tokens);
tokens
};
let response_types = {
let mut tokens = Tokens::new();
self.response.to_tokens(&mut tokens);
tokens
};
let set_request_path = if self.request.has_path_fields() {
let path_str_quoted = path.as_str();
assert!(
path_str_quoted.starts_with('"') && path_str_quoted.ends_with('"'),
"path needs to be a string literal"
);
let path_str = &path_str_quoted[1 .. path_str_quoted.len() - 1];
assert!(path_str.starts_with('/'), "path needs to start with '/'");
assert!(
path_str.chars().filter(|c| *c == ':').count() == self.request.path_field_count(),
"number of declared path parameters needs to match amount of placeholders in path"
);
let request_path_init_fields = self.request.request_path_init_fields();
let mut tokens = quote! {
let request_path = RequestPath {
#request_path_init_fields
};
// This `unwrap()` can only fail when the url is a
// cannot-be-base url like `mailto:` or `data:`, which is not
// the case for our placeholder url.
let mut path_segments = url.path_segments_mut().unwrap();
};
for segment in path_str[1..].split('/') {
tokens.append(quote! {
path_segments.push
});
tokens.append("(");
if segment.starts_with(':') {
tokens.append("&request_path.");
tokens.append(&segment[1..]);
tokens.append(".to_string()");
} else {
tokens.append("\"");
tokens.append(segment);
tokens.append("\"");
}
tokens.append(");");
}
tokens
} else {
quote! {
url.set_path(metadata.path);
}
};
let set_request_query = if self.request.has_query_fields() {
let request_query_init_fields = self.request.request_query_init_fields();
quote! {
let request_query = RequestQuery {
#request_query_init_fields
};
url.set_query(Some(&::serde_urlencoded::to_string(request_query)?));
}
} else {
Tokens::new()
};
let add_body_to_request = if let Some(field) = self.request.newtype_body_field() {
let field_name = field.ident.as_ref().expect("expected body field to have a name");
quote! {
let request_body = RequestBody(request.#field_name);
hyper_request.set_body(::serde_json::to_vec(&request_body)?);
}
} else if self.request.has_body_fields() {
let request_body_init_fields = self.request.request_body_init_fields();
quote! {
let request_body = RequestBody {
#request_body_init_fields
};
hyper_request.set_body(::serde_json::to_vec(&request_body)?);
}
} else {
Tokens::new()
};
let deserialize_response_body = if let Some(field) = self.response.newtype_body_field() {
let field_type = &field.ty;
let mut tokens = Tokens::new();
tokens.append(quote! {
let future_response = hyper_response.body()
.fold::<_, _, Result<_, ::std::io::Error>>(Vec::new(), |mut bytes, chunk| {
bytes.write_all(&chunk)?;
Ok(bytes)
})
.map_err(::ruma_api::Error::from)
.and_then(|bytes| {
::serde_json::from_slice::<#field_type>(bytes.as_slice())
.map_err(::ruma_api::Error::from)
})
});
tokens.append(".and_then(move |response_body| {");
tokens
} else if self.response.has_body_fields() {
let mut tokens = Tokens::new();
tokens.append(quote! {
let future_response = hyper_response.body()
.fold::<_, _, Result<_, ::std::io::Error>>(Vec::new(), |mut bytes, chunk| {
bytes.write_all(&chunk)?;
Ok(bytes)
})
.map_err(::ruma_api::Error::from)
.and_then(|bytes| {
::serde_json::from_slice::<ResponseBody>(bytes.as_slice())
.map_err(::ruma_api::Error::from)
})
});
tokens.append(".and_then(move |response_body| {");
tokens
} else {
let mut tokens = Tokens::new();
tokens.append(quote! {
let future_response = ::futures::future::ok(())
});
tokens.append(".and_then(move |_| {");
tokens
};
let mut closure_end = Tokens::new();
closure_end.append("});");
let extract_headers = if self.response.has_header_fields() {
quote! {
let mut headers = hyper_response.headers().clone();
}
} else {
Tokens::new()
};
let response_init_fields = if self.response.has_fields() {
self.response.init_fields()
} else {
Tokens::new()
};
tokens.append(quote! {
#[allow(unused_imports)]
use std::io::Write as _Write;
#[allow(unused_imports)]
use ::futures::{Future as _Future, Stream as _Stream};
use ::ruma_api::Endpoint as _RumaApiEndpoint;
/// The API endpoint.
#[derive(Debug)]
pub struct Endpoint;
#request_types
impl ::std::convert::TryFrom<Request> for ::hyper::Request {
type Error = ::ruma_api::Error;
#[allow(unused_mut, unused_variables)]
fn try_from(request: Request) -> Result<Self, Self::Error> {
let metadata = Endpoint::METADATA;
// Use dummy homeserver url which has to be overwritten in
// the calling code. Previously (with hyper::Uri) this was
// not required, but Url::parse only accepts absolute urls.
let mut url = ::url::Url::parse("http://invalid-host-please-change/").unwrap();
{ #set_request_path }
{ #set_request_query }
let mut hyper_request = ::hyper::Request::new(
metadata.method,
// Every valid URL is a valid URI
url.into_string().parse().unwrap(),
);
{ #add_body_to_request }
Ok(hyper_request)
}
}
#response_types
impl ::futures::future::FutureFrom<::hyper::Response> for Response {
type Future = Box<_Future<Item = Self, Error = Self::Error>>;
type Error = ::ruma_api::Error;
#[allow(unused_variables)]
fn future_from(hyper_response: ::hyper::Response)
-> Box<_Future<Item = Self, Error = Self::Error>> {
#extract_headers
#deserialize_response_body
let response = Response {
#response_init_fields
};
Ok(response)
#closure_end
Box::new(future_response)
}
}
impl ::ruma_api::Endpoint for Endpoint {
type Request = Request;
type Response = Response;
const METADATA: ::ruma_api::Metadata = ::ruma_api::Metadata {
description: #description,
method: ::hyper::#method,
name: #name,
path: #path,
rate_limited: #rate_limited,
requires_authentication: #requires_authentication,
};
}
});
}
}
impl From<Vec<Entry>> for Api {
fn from(entries: Vec<Entry>) -> Api {
if entries.len() != 3 {
panic!("ruma_api! expects 3 blocks: metadata, request, and response");
}
let mut metadata = None;
let mut request = None;
let mut response = None;
for entry in entries {
match entry {
Entry::Metadata(fields) => metadata = Some(Metadata::from(fields)),
Entry::Request(fields) => request = Some(Request::from(fields)),
Entry::Response(fields) => response = Some(Response::from(fields)),
}
}
Api {
metadata: metadata.expect("ruma_api! is missing metadata"),
request: request.expect("ruma_api! is missing request"),
response: response.expect("ruma_api! is missing response"),
}
}
}