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use proc_macro::TokenStream;
use quote::quote;
mod api_def;
#[proc_macro]
pub fn rpc_api(input_token_stream: TokenStream) -> TokenStream {
// Start by parsing the input into what we expect.
let defs: api_def::ApiDefinitions = syn::parse(input_token_stream)
.expect("failed to parse input");
let out: Vec<_> = defs.apis.into_iter().map(build_api).collect();
TokenStream::from(quote!{
#(#out)*
})
}
/// Generates the macro output token stream corresponding to a single API.
fn build_api(api: api_def::ApiDefinition) -> proc_macro2::TokenStream {
let enum_name = &api.name;
let visibility = &api.visibility;
let mut variants = Vec::new();
for function in &api.definitions {
let ret = match &function.output {
syn::ReturnType::Default => quote!{()},
syn::ReturnType::Type(_, ty) => quote!{#ty},
};
variants.push(quote!{
#variant_name {
respond: jsonrpsee::core::server::TypedResponder<'a, R, I, #ret>,
}
});
}
let next_request = {
let mut function_blocks = Vec::new();
for function in &api.definitions {
let rpc_method_name = function.ident.to_string();
function_blocks.push(quote!{
if method == #rpc_method_name {
let request = server.request_by_id(&request_id).unwrap();
/*$(
let $pn: $pty = {
let raw_val = match request.params().get(stringify!($pn)) {
Some(v) => v,
None => {
request.respond(Err(jsonrpsee::core::common::Error::invalid_params("foo"))).await; // TODO: message
continue;
}
};
match jsonrpsee::core::common::from_value(raw_val.clone()) {
Ok(v) => v,
Err(_) => {
request.respond(Err(jsonrpsee::core::common::Error::invalid_params("foo"))).await; // TODO: message
continue;
}
}
};
)**/
let respond = jsonrpsee::core::server::TypedResponder {
rq: request,
response_ty: std::marker::PhantomData,
};
#visibility async fn next_request(server: &'a mut jsonrpsee::core::server::Server<R, I>) -> Result<#enum_name<'a, R, I>, std::io::Error>
where R: jsonrpsee::core::server::raw::RawServer<RequestId = I>,
I: Clone + PartialEq + Eq + Send + Sync,
{
loop {
let (request_id, method) = match server.next_event().await.unwrap() { // TODO: don't unwrap
jsonrpsee::core::server::ServerEvent::Notification(n) => unimplemented!(), // TODO:
jsonrpsee::core::server::ServerEvent::Request(r) => (r.id(), r.method().to_owned()),
};
#(#function_blocks)*
server.request_by_id(&request_id).unwrap().respond(Err(jsonrpsee::core::common::Error::method_not_found())).await;
}
}
}
};
// Builds the functions that allow performing outbound JSON-RPC queries.
let mut client_functions = Vec::new();
for function in &api.definitions {
let f_name = &function.ident;
let ret_ty = &function.output;
let rpc_method_name = function.ident.to_string();
let mut params_list = Vec::new();
let mut params_to_json = Vec::new();
for (param_index, input) in function.inputs.iter().enumerate() {
let ty = match input {
syn::FnArg::Receiver(_) => panic!("Having `self` is not allowed in RPC queries definitions"),
syn::FnArg::Typed(syn::PatType { ty, .. }) => ty,
};
let generated_param_name = syn::Ident::new(
&format!("param{}", param_index),
proc_macro2::Span::call_site()
);
params_list.push(quote!{#generated_param_name: #ty});
params_to_json.push(quote!{
let #generated_param_name = jsonrpsee::common::to_value(#generated_param_name).unwrap(); // TODO: don't unwrap
});
}
// TODO: what if there's a conflict in the param name?
#visibility async fn #f_name(client: &mut jsonrpsee::core::client::Client<impl jsonrpsee::core::client::raw::RawClient> #(, #params_list)*) #ret_ty {
// TODO: don't unwrap
client.request(#rpc_method_name).await.unwrap()
#visibility enum #enum_name<'a, R, I> {
#(#variants),*
}
impl<'a, R, I> #enum_name<'a, R, I> {
#next_request
}
impl<'a> #enum_name<'a, (), ()> {
#(#client_functions)*
}