Merge pull request #854 from ethcore/ipc-prox

Syntax helpers for IPC RPC (part 2)
This commit is contained in:
Gav Wood 2016-04-03 07:24:09 -04:00
commit da315845ff
6 changed files with 341 additions and 26 deletions

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@ -25,6 +25,7 @@ use syntax::ast::{
Arg,
PatKind,
FunctionRetTy,
Ty,
};
use syntax::ast;
@ -52,11 +53,13 @@ pub fn expand_ipc_implementation(
let builder = aster::AstBuilder::new().span(span);
let impl_item = match implement_interface(cx, &builder, &item, push) {
Ok(item) => item,
let (impl_item, dispatches) = match implement_interface(cx, &builder, &item, push) {
Ok((item, dispatches)) => (item, dispatches),
Err(Error) => { return; }
};
push_client(cx, &builder, &item, &dispatches, push);
push(Annotatable::Item(impl_item))
}
@ -75,36 +78,41 @@ fn push_invoke_signature_aster(
) -> Dispatch {
let inputs = &signature.decl.inputs;
let (input_type_name, input_arg_names) = if inputs.len() > 0 {
let (input_type_name, input_arg_names, input_arg_tys) = if inputs.len() > 0 {
let first_field_name = field_name(builder, &inputs[0]).name.as_str();
if first_field_name == "self" && inputs.len() == 1 { (None, vec![]) }
if first_field_name == "self" && inputs.len() == 1 { (None, vec![], vec![]) }
else {
let skip = if first_field_name == "self" { 2 } else { 1 };
let name_str = format!("{}_input", implement.ident.name.as_str());
let mut arg_names = Vec::new();
let mut arg_tys = Vec::new();
let arg_name = format!("{}", field_name(builder, &inputs[skip-1]).name);
let arg_ty = inputs[skip-1].ty.clone();
let mut tree = builder.item()
.attr().word("derive(Serialize, Deserialize)")
.attr().word("allow(non_camel_case_types)")
.struct_(name_str.as_str())
.field(arg_name.as_str()).ty().build(inputs[skip-1].ty.clone());
.field(arg_name.as_str()).ty().build(arg_ty.clone());
arg_names.push(arg_name);
arg_tys.push(arg_ty.clone());
for arg in inputs.iter().skip(skip) {
let arg_name = format!("{}", field_name(builder, &arg));
tree = tree.field(arg_name.as_str()).ty().build(arg.ty.clone());
let arg_ty = arg.ty.clone();
tree = tree.field(arg_name.as_str()).ty().build(arg_ty.clone());
arg_names.push(arg_name);
arg_tys.push(arg_ty);
}
push(Annotatable::Item(tree.build()));
(Some(name_str.to_owned()), arg_names)
(Some(name_str.to_owned()), arg_names, arg_tys)
}
}
else {
(None, vec![])
(None, vec![], vec![])
};
let return_type_name = match signature.decl.output {
let (return_type_name, return_type_ty) = match signature.decl.output {
FunctionRetTy::Ty(ref ty) => {
let name_str = format!("{}_output", implement.ident.name.as_str());
let tree = builder.item()
@ -113,16 +121,18 @@ fn push_invoke_signature_aster(
.struct_(name_str.as_str())
.field(format!("payload")).ty().build(ty.clone());
push(Annotatable::Item(tree.build()));
Some(name_str.to_owned())
(Some(name_str.to_owned()), Some(ty.clone()))
}
_ => None
_ => (None, None)
};
Dispatch {
function_name: format!("{}", implement.ident.name.as_str()),
input_type_name: input_type_name,
input_arg_names: input_arg_names,
input_arg_tys: input_arg_tys,
return_type_name: return_type_name,
return_type_ty: return_type_ty,
}
}
@ -130,7 +140,9 @@ struct Dispatch {
function_name: String,
input_type_name: Option<String>,
input_arg_names: Vec<String>,
input_arg_tys: Vec<P<Ty>>,
return_type_name: Option<String>,
return_type_ty: Option<P<Ty>>,
}
fn implement_dispatch_arm_invoke(
@ -212,6 +224,7 @@ fn implement_dispatch_arm_invoke(
})
}
/// generates dispatch match for method id
fn implement_dispatch_arm(cx: &ExtCtxt, builder: &aster::AstBuilder, index: u32, dispatch: &Dispatch)
-> ast::Arm
{
@ -220,12 +233,256 @@ fn implement_dispatch_arm(cx: &ExtCtxt, builder: &aster::AstBuilder, index: u32,
quote_arm!(cx, $index_ident => { $invoke_expr } )
}
/// generates client type for specified server type
/// for say `Service` it generates `ServiceClient`
fn push_client_struct(cx: &ExtCtxt, builder: &aster::AstBuilder, item: &Item, push: &mut FnMut(Annotatable)) {
let proxy_ident = builder.id(format!("{}Client", item.ident.name.as_str()));
let proxy_struct_item = quote_item!(cx,
pub struct $proxy_ident <S: ::ipc::IpcSocket> {
socket: ::std::cell::RefCell<S>,
phantom: ::std::marker::PhantomData<S>,
});
push(Annotatable::Item(proxy_struct_item.expect(&format!("could not generate proxy struct for {:?}", proxy_ident.name))));
}
/// pushes generated code for the client class (type declaration and method invocation implementations)
fn push_client(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
item: &Item,
dispatches: &[Dispatch],
push: &mut FnMut(Annotatable))
{
push_client_struct(cx, builder, item, push);
push_client_implementation(cx, builder, dispatches, item, push);
}
/// returns an expression with the body for single operation that is being sent to server
/// operation itself serializes input, writes to socket and waits for socket to respond
/// (the latter only if original method signature returns anyting)
///
/// assuming expanded class contains method
/// fn commit(&self, f: u32) -> u32
///
/// the expanded implementation will generate method for the client like that
/// #[derive(Serialize)]
/// struct Request<'a> {
/// f: &'a u32,
/// }
/// let payload = Request{f: &f,};
/// let mut socket_ref = self.socket.borrow_mut();
/// let mut socket = socket_ref.deref_mut();
/// let serialized_payload = ::bincode::serde::serialize(&payload, ::bincode::SizeLimit::Infinite).unwrap();
/// ::ipc::invoke(0, &Some(serialized_payload), &mut socket);
/// while !socket.ready().load(::std::sync::atomic::Ordering::Relaxed) { }
/// ::bincode::serde::deserialize_from::<_, u32>(&mut socket, ::bincode::SizeLimit::Infinite).unwrap()
fn implement_client_method_body(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
index: u16,
dispatch: &Dispatch,
)
-> P<ast::Expr>
{
let request = if dispatch.input_arg_names.len() > 0 {
let arg_name = dispatch.input_arg_names[0].as_str();
let arg_ty = builder
.ty().ref_()
.lifetime("'a")
.ty().build(dispatch.input_arg_tys[0].clone());
let mut tree = builder.item()
.attr().word("derive(Serialize)")
.struct_("Request")
.generics()
.lifetime_name("'a")
.build()
.field(arg_name).ty().build(arg_ty);
for arg_idx in 1..dispatch.input_arg_names.len() {
let arg_name = dispatch.input_arg_names[arg_idx].as_str();
let arg_ty = builder
.ty().ref_()
.lifetime("'a")
.ty().build(dispatch.input_arg_tys[arg_idx].clone());
tree = tree.field(arg_name).ty().build(arg_ty);
}
let mut request_serialization_statements = Vec::new();
let struct_tree = tree.build();
let struct_stmt = quote_stmt!(cx, $struct_tree);
request_serialization_statements.push(struct_stmt);
// actually this is just expanded version of this:
// request_serialization_statements.push(quote_stmt!(cx, let payload = Request { p1: &p1, p2: &p2, ... pn: &pn, }));
// again, cannot dynamically create expression with arbitrary number of comma-separated members
request_serialization_statements.push({
let ext_cx = &*cx;
::quasi::parse_stmt_panic(&mut ::syntax::parse::new_parser_from_tts(
ext_cx.parse_sess(),
ext_cx.cfg(),
{
let _sp = ext_cx.call_site();
let mut tt = ::std::vec::Vec::new();
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("let"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("payload"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Eq));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("Request"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::OpenDelim(::syntax::parse::token::Brace)));
for arg in dispatch.input_arg_names.iter() {
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of(arg.as_str()), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Colon));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::BinOp(::syntax::parse::token::And)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of(arg.as_str()), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Comma));
}
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::CloseDelim(::syntax::parse::token::Brace)));
tt
}))
});
request_serialization_statements.push(
quote_stmt!(cx, let mut socket_ref = self.socket.borrow_mut()));
request_serialization_statements.push(
quote_stmt!(cx, let mut socket = socket_ref.deref_mut()));
request_serialization_statements.push(
quote_stmt!(cx, let serialized_payload = ::bincode::serde::serialize(&payload, ::bincode::SizeLimit::Infinite).unwrap()));
let index_ident = builder.id(format!("{}", index).as_str());
request_serialization_statements.push(
quote_stmt!(cx, ::ipc::invoke($index_ident, &Some(serialized_payload), &mut socket)));
request_serialization_statements
}
else {
vec![]
};
let wait_result_stmt = quote_stmt!(cx, while !socket.ready().load(::std::sync::atomic::Ordering::Relaxed) { });
if let Some(ref return_ty) = dispatch.return_type_ty {
let return_expr = quote_expr!(cx,
::bincode::serde::deserialize_from::<_, $return_ty>(&mut socket, ::bincode::SizeLimit::Infinite).unwrap()
);
quote_expr!(cx, {
$request
$wait_result_stmt
$return_expr
})
}
else {
quote_expr!(cx, {
$request
$wait_result_stmt
})
}
}
/// Generates signature and body (see `implement_client_method_body`)
/// for the client (signature is identical to the original method)
fn implement_client_method(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
index: u16,
dispatch: &Dispatch)
-> ast::ImplItem
{
let method_name = builder.id(dispatch.function_name.as_str());
let body = implement_client_method_body(cx, builder, index, dispatch);
let ext_cx = &*cx;
// expanded version of this
// pub fn $method_name(&self, p1: p1_ty, p2: p2_ty ... pn: pn_ty, ) [-> return_ty] { $body }
// looks like it's tricky to build function declaration with aster if body already generated
let signature = ::syntax::parse::parser::Parser::parse_impl_item(
&mut ::syntax::parse::new_parser_from_tts(
ext_cx.parse_sess(),
ext_cx.cfg(),
{
let _sp = ext_cx.call_site();
let mut tt = ::std::vec::Vec::new();
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("pub"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("fn"), ::syntax::parse::token::Plain)));
tt.extend(::quasi::ToTokens::to_tokens(&method_name, ext_cx).into_iter());
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::OpenDelim(::syntax::parse::token::Paren)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::BinOp(::syntax::parse::token::And)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of("self"), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Comma));
for arg_idx in 0..dispatch.input_arg_names.len() {
let arg_name = dispatch.input_arg_names[arg_idx].as_str();
let arg_ty = dispatch.input_arg_tys[arg_idx].clone();
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Ident(ext_cx.ident_of(arg_name), ::syntax::parse::token::Plain)));
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Colon));
tt.extend(::quasi::ToTokens::to_tokens(&arg_ty, ext_cx).into_iter());
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::Comma));
}
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::CloseDelim(::syntax::parse::token::Paren)));
if let Some(ref return_ty) = dispatch.return_type_ty {
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::RArrow));
tt.extend(::quasi::ToTokens::to_tokens(return_ty, ext_cx).into_iter());
}
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::OpenDelim(::syntax::parse::token::Brace)));
tt.extend(::quasi::ToTokens::to_tokens(&body, ext_cx).into_iter());
tt.push(::syntax::ast::TokenTree::Token(_sp, ::syntax::parse::token::CloseDelim(::syntax::parse::token::Brace)));
tt
}));
signature.unwrap()
}
/// pushes full client side code for the original class exposed via ipc
fn push_client_implementation(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
dispatches: &[Dispatch],
item: &Item,
push: &mut FnMut(Annotatable))
{
let mut index = -1i32;
let items = dispatches.iter()
.map(|dispatch| { index = index + 1; P(implement_client_method(cx, builder, index as u16, dispatch)) })
.collect::<Vec<P<ast::ImplItem>>>();
let client_ident = builder.id(format!("{}Client", item.ident.name.as_str()));
let implement = quote_item!(cx,
impl<S> $client_ident<S> where S: ::ipc::IpcSocket {
pub fn new(socket: S) -> $client_ident<S> {
$client_ident {
socket: ::std::cell::RefCell::new(socket),
phantom: ::std::marker::PhantomData,
}
}
#[cfg(test)]
pub fn socket(&self) -> &::std::cell::RefCell<S> {
&self.socket
}
$items
}).unwrap();
push(Annotatable::Item(implement));
}
/// implements `IpcInterface<C>` for the given class `C`
fn implement_interface(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
item: &Item,
push: &mut FnMut(Annotatable),
) -> Result<P<ast::Item>, Error> {
) -> Result<(P<ast::Item>, Vec<Dispatch>), Error> {
let (generics, impl_items) = match item.node {
ast::ItemKind::Impl(_, _, ref generics, _, _, ref impl_items) => (generics, impl_items),
_ => {
@ -258,7 +515,7 @@ fn implement_interface(
let dispatch_arms: Vec<_> = dispatch_table.iter()
.map(|dispatch| { index = index + 1; implement_dispatch_arm(cx, builder, index as u32, dispatch) }).collect();
Ok(quote_item!(cx,
Ok((quote_item!(cx,
impl $impl_generics ::ipc::IpcInterface<$ty> for $ty $where_clause {
fn dispatch<R>(&self, r: &mut R) -> Vec<u8>
where R: ::std::io::Read
@ -274,11 +531,6 @@ fn implement_interface(
_ => vec![]
}
}
fn invoke<W>(&self, _method_num: u16, _payload: &Option<Vec<u8>>, _w: &mut W)
where W: ::std::io::Write
{
}
}
).unwrap())
).unwrap(), dispatch_table))
}

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@ -7,3 +7,4 @@ license = "GPL-3.0"
[features]
[dependencies]
ethcore-devtools = { path = "../../devtools" }

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@ -16,9 +16,43 @@
//! IPC RPC interface
use std::io::{Read, Write};
use std::marker::Sync;
use std::sync::atomic::*;
pub trait IpcInterface<T> {
/// reads the message from io, dispatches the call and returns result
fn dispatch<R>(&self, r: &mut R) -> Vec<u8> where R: ::std::io::Read;
/// encodes the invocation, writes payload and waits for result
fn invoke<W>(&self, method_num: u16, params: &Option<Vec<u8>>, w: &mut W) where W: ::std::io::Write;
fn dispatch<R>(&self, r: &mut R) -> Vec<u8> where R: Read;
}
/// serializes method invocation (method_num and parameters) to the stream specified by `w`
pub fn invoke<W>(method_num: u16, params: &Option<Vec<u8>>, w: &mut W) where W: Write {
// creating buffer to contain all message
let buf_len = match *params { None => 2, Some(ref val) => val.len() + 2 };
let mut buf = vec![0u8; buf_len];
// writing method_num as u16
buf[1] = (method_num & 255) as u8;
buf[0] = (method_num >> 8) as u8;
// serializing parameters only if provided with any
if params.is_some() {
buf[2..buf_len].clone_from_slice(params.as_ref().unwrap());
}
if w.write(&buf).unwrap() != buf_len
{
// if write was inconsistent
panic!("failed to write to socket");
}
}
/// IpcSocket
pub trait IpcSocket: Read + Write + Sync {
fn ready(&self) -> AtomicBool;
}
impl IpcSocket for ::devtools::TestSocket {
fn ready(&self) -> AtomicBool {
AtomicBool::new(true)
}
}

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@ -16,5 +16,7 @@
//! IPC RPC interface
extern crate ethcore_devtools as devtools;
pub mod interface;
pub use interface::IpcInterface;
pub use interface::{IpcInterface, IpcSocket, invoke};

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@ -33,4 +33,28 @@ mod tests {
assert_eq!(10, *service.commits.read().unwrap());
}
#[test]
fn call_service_proxy() {
let mut socket = TestSocket::new();
socket.read_buffer = vec![0, 0, 0, 10];
let service_client = ServiceClient::new(socket);
let result = service_client.commit(5);
assert_eq!(vec![0, 0, 0, 0, 0, 5], service_client.socket().borrow().write_buffer.clone());
assert_eq!(10, result);
}
#[test]
fn call_service_proxy_optional() {
let mut socket = TestSocket::new();
socket.read_buffer = vec![0, 0, 0, 10];
let service_client = ServiceClient::new(socket);
let result = service_client.rollback(Some(5), 10);
assert_eq!(vec![0, 1, 1, 0, 0, 0, 5, 0, 0, 0, 10], service_client.socket().borrow().write_buffer.clone());
assert_eq!(10, result);
}
}

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@ -15,6 +15,7 @@
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
use std::sync::RwLock;
use std::ops::*;
pub struct Service {
pub commits: RwLock<usize>,
@ -28,10 +29,11 @@ impl Service {
*lock = *lock + f as usize;
f
}
pub fn rollback(&self, a: u32, b: u32) -> i32 {
pub fn rollback(&self, a: Option<u32>, b: u32) -> i32 {
let a_0 = a.unwrap_or_else(|| 0);
let mut lock = self.rollbacks.write().unwrap();
*lock = *lock + a as usize - b as usize;
(a - b) as i32
*lock = *lock + a_0 as usize - b as usize;
(a_0 - b) as i32
}
}