279 lines
10 KiB
Rust

use proc_macro2::{Ident, Span, TokenStream};
use quote::quote;
use super::{Metadata, Request, RequestField, RequestFieldKind};
impl Request {
pub fn expand_incoming(
&self,
metadata: &Metadata,
error_ty: &TokenStream,
ruma_api: &TokenStream,
) -> TokenStream {
let bytes = quote! { #ruma_api::exports::bytes };
let http = quote! { #ruma_api::exports::http };
let percent_encoding = quote! { #ruma_api::exports::percent_encoding };
let ruma_serde = quote! { #ruma_api::exports::ruma_serde };
let serde_json = quote! { #ruma_api::exports::serde_json };
let method = &metadata.method;
let incoming_request_type =
if self.contains_lifetimes() { quote!(IncomingRequest) } else { quote!(Request) };
let (parse_request_path, path_vars) = if self.has_path_fields() {
let path_string = metadata.path.value();
assert!(path_string.starts_with('/'), "path needs to start with '/'");
assert!(
path_string.chars().filter(|c| *c == ':').count() == self.path_field_count(),
"number of declared path parameters needs to match amount of placeholders in path"
);
let path_var_decls = path_string[1..]
.split('/')
.enumerate()
.filter(|(_, seg)| seg.starts_with(':'))
.map(|(i, seg)| {
let path_var = Ident::new(&seg[1..], Span::call_site());
quote! {
let #path_var = {
let segment = path_segments[#i].as_bytes();
let decoded =
#percent_encoding::percent_decode(segment).decode_utf8()?;
::std::convert::TryFrom::try_from(&*decoded)?
};
}
});
let parse_request_path = quote! {
let path_segments: ::std::vec::Vec<&::std::primitive::str> =
request.uri().path()[1..].split('/').collect();
#(#path_var_decls)*
};
let path_vars = path_string[1..]
.split('/')
.filter(|seg| seg.starts_with(':'))
.map(|seg| Ident::new(&seg[1..], Span::call_site()));
(parse_request_path, quote! { #(#path_vars,)* })
} else {
(TokenStream::new(), TokenStream::new())
};
let (parse_query, query_vars) = if let Some(field) = self.query_map_field() {
let field_name = field.ident.as_ref().expect("expected field to have an identifier");
let parse = quote! {
let #field_name = #ruma_serde::urlencoded::from_str(
&request.uri().query().unwrap_or(""),
)?;
};
(parse, quote! { #field_name, })
} else if self.has_query_fields() {
let (decls, names) = self.vars(RequestFieldKind::Query, quote!(request_query));
let parse = quote! {
let request_query: <RequestQuery as #ruma_serde::Outgoing>::Incoming =
#ruma_serde::urlencoded::from_str(
&request.uri().query().unwrap_or("")
)?;
#decls
};
(parse, names)
} else {
(TokenStream::new(), TokenStream::new())
};
let (parse_headers, header_vars) = if self.has_header_fields() {
let (decls, names): (TokenStream, Vec<_>) = self
.header_fields()
.map(|request_field| {
let (field, header_name) = match request_field {
RequestField::Header(field, header_name) => (field, header_name),
_ => panic!("expected request field to be header variant"),
};
let field_name = &field.ident;
let header_name_string = header_name.to_string();
let (some_case, none_case) = match &field.ty {
syn::Type::Path(syn::TypePath {
path: syn::Path { segments, .. }, ..
}) if segments.last().unwrap().ident == "Option" => {
(quote! { Some(str_value.to_owned()) }, quote! { None })
}
_ => (
quote! { str_value.to_owned() },
quote! {
return Err(
#ruma_api::error::HeaderDeserializationError::MissingHeader(
#header_name_string.into()
).into(),
)
},
),
};
let decl = quote! {
let #field_name = match headers.get(#http::header::#header_name) {
Some(header_value) => {
let str_value = header_value.to_str()?;
#some_case
}
None => #none_case,
};
};
(decl, field_name)
})
.unzip();
let parse = quote! {
let headers = request.headers();
#decls
};
(parse, quote! { #(#names,)* })
} else {
(TokenStream::new(), TokenStream::new())
};
let extract_body = if self.has_body_fields() || self.newtype_body_field().is_some() {
let body_lifetimes = if self.has_body_lifetimes() {
// duplicate the anonymous lifetime as many times as needed
let lifetimes = std::iter::repeat(quote! { '_ }).take(self.lifetimes.body.len());
quote! { < #( #lifetimes, )* >}
} else {
TokenStream::new()
};
quote! {
let request_body: <
RequestBody #body_lifetimes
as #ruma_serde::Outgoing
>::Incoming = {
let body = request.into_body();
if #bytes::Buf::has_remaining(&body) {
#serde_json::from_reader(#bytes::Buf::reader(body))?
} else {
// If the request body is completely empty, pretend it is an empty JSON
// object instead. This allows requests with only optional body parameters
// to be deserialized in that case.
#serde_json::from_str("{}")?
}
};
}
} else {
TokenStream::new()
};
let (parse_body, body_vars) = if let Some(field) = self.newtype_body_field() {
let field_name = field.ident.as_ref().expect("expected field to have an identifier");
let parse = quote! {
let #field_name = request_body.0;
};
(parse, quote! { #field_name, })
} else if let Some(field) = self.newtype_raw_body_field() {
let field_name = field.ident.as_ref().expect("expected field to have an identifier");
let parse = quote! {
let #field_name = {
let mut reader = #bytes::Buf::reader(request.into_body());
let mut vec = ::std::vec::Vec::new();
::std::io::Read::read_to_end(&mut reader, &mut vec)
.expect("reading from a bytes::Buf never fails");
vec
};
};
(parse, quote! { #field_name, })
} else {
self.vars(RequestFieldKind::Body, quote!(request_body))
};
let non_auth_impls = metadata.authentication.iter().map(|auth| {
if auth.value == "None" {
let attrs = &auth.attrs;
quote! {
#( #attrs )*
#[automatically_derived]
#[cfg(feature = "server")]
impl #ruma_api::IncomingNonAuthRequest for #incoming_request_type {}
}
} else {
TokenStream::new()
}
});
quote! {
#[automatically_derived]
#[cfg(feature = "server")]
#[allow(clippy::inconsistent_struct_constructor)]
impl #ruma_api::IncomingRequest for #incoming_request_type {
type EndpointError = #error_ty;
type OutgoingResponse = Response;
const METADATA: #ruma_api::Metadata = self::METADATA;
fn try_from_http_request<T: #bytes::Buf>(
request: #http::Request<T>
) -> ::std::result::Result<Self, #ruma_api::error::FromHttpRequestError> {
if request.method() != #http::Method::#method {
return Err(#ruma_api::error::FromHttpRequestError::MethodMismatch {
expected: #http::Method::#method,
received: request.method().clone(),
});
}
#parse_request_path
#parse_query
#parse_headers
#extract_body
#parse_body
Ok(Self {
#path_vars
#query_vars
#header_vars
#body_vars
})
}
}
#(#non_auth_impls)*
}
}
fn vars(
&self,
request_field_kind: RequestFieldKind,
src: TokenStream,
) -> (TokenStream, TokenStream) {
self.fields
.iter()
.filter_map(|f| f.field_of_kind(request_field_kind))
.map(|field| {
let field_name =
field.ident.as_ref().expect("expected field to have an identifier");
let cfg_attrs =
field.attrs.iter().filter(|a| a.path.is_ident("cfg")).collect::<Vec<_>>();
let decl = quote! {
#( #cfg_attrs )*
let #field_name = #src.#field_name;
};
(decl, quote! { #field_name, })
})
.unzip()
}
}