feat: use dlc-macros for async dlc-manager

Cargo.toml

@@ -8,6 +8,7 @@ members = [
   "dlc-messages",
   "dlc-trie",
   "dlc-manager",
+  "dlc-macros",
   "mocks",
   "sample",
   "simple-wallet",

dlc-macros/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "dlc-macros"
+authors = ["benny b <[email protected]>"]
+version = "0.1.0"
+edition = "2018"
+description = "Procedural macros for writing optionally asynchronous code for traits and functions."
+homepage = "https://github.com/p2pderivatives/rust-dlc"
+license-file = "../LICENSE"
+repository = "https://github.com/p2pderivatives/rust-dlc/tree/master/dlc-macros"
+
+[dependencies]
+proc-macro2 = "1.0.87"
+quote = "1.0.37"
+syn = { version = "2.0.79", features = ["full", "extra-traits"] }
+tokio = { version = "1.40.0", features = ["macros", "test-util"] }
+
+[lib]
+proc-macro = true
+
+[dev-dependencies]
+trybuild = "1.0.99"

dlc-macros/src/lib.rs

@@ -0,0 +1,190 @@
+//! Procedural macros for writing optionally asynchronous code for traits and functions.
+//! Inspires by [`bdk-macros`](https://github.com/bitcoindevkit/bdk/blob/v0.29.0/macros/src/lib.rs)
+
+#![crate_name = "dlc_macros"]
+// Coding conventions
+#![forbid(unsafe_code)]
+#![deny(non_upper_case_globals)]
+#![deny(non_camel_case_types)]
+#![deny(non_snake_case)]
+#![deny(unused_mut)]
+#![deny(dead_code)]
+#![deny(unused_imports)]
+#![deny(missing_docs)]
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::spanned::Spanned;
+use syn::{
+    parse_macro_input, Attribute, Expr, ImplItem, Item, ItemFn, ItemImpl, ItemTrait, TraitItem,
+};
+
+// Check if the function attributes contains #[maybe_async].
+// For conditional compilation of member functions.
+fn is_maybe_async_attr(attr: &Attribute) -> bool {
+    // Check if the attribute path is exactly "maybe_async"
+    if attr.path().is_ident("maybe_async") {
+        return true;
+    }
+
+    // Check if the attribute path is of the form "module::maybe_async"
+    if let Some(last_segment) = attr.path().segments.last() {
+        return last_segment.ident == "maybe_async";
+    }
+    false
+}
+
+// Add async to a standalone function.
+fn add_async_to_fn(mut func: ItemFn) -> TokenStream {
+    // For standalone functions, we'll always make them potentially async
+    let sync_version = func.clone();
+    func.sig.asyncness = Some(syn::Token![async](func.sig.span()));
+
+    quote! {
+        #[cfg(not(feature = "async"))]
+        #sync_version
+
+        #[cfg(feature = "async")]
+        #func
+    }
+    .into()
+}
+
+// Adds the `async_trait` macro to the trait and appends async to all of
+// the member functions marked `#[maybe_async]`.
+fn add_async_to_trait(mut trait_item: ItemTrait) -> TokenStream {
+    // Check if the trait itself has the `#[maybe_async]` attribute
+    let is_trait_async = trait_item.attrs.iter().any(is_maybe_async_attr);
+    trait_item.attrs.retain(|attr| !is_maybe_async_attr(attr)); // Remove the attribute from the trait
+
+    let mut async_trait_item = trait_item.clone();
+
+    for item in &mut async_trait_item.items {
+        if let TraitItem::Fn(method) = item {
+            if is_trait_async || method.attrs.iter().any(is_maybe_async_attr) {
+                method.sig.asyncness = Some(syn::Token![async](method.sig.span()));
+                method.attrs.retain(is_maybe_async_attr);
+            }
+        }
+    }
+
+    quote! {
+        #[cfg(not(feature = "async"))]
+        #trait_item
+
+        #[cfg(feature = "async")]
+        #[async_trait::async_trait]
+        #async_trait_item
+    }
+    .into()
+}
+
+// Adds async to a member of a struct implementation method.
+fn add_async_to_impl(impl_item: ItemImpl) -> TokenStream {
+    let mut async_impl_item = impl_item.clone();
+
+    for item in &mut async_impl_item.items {
+        if let ImplItem::Fn(method) = item {
+            if method.attrs.iter().any(is_maybe_async_attr) {
+                method.sig.asyncness = Some(syn::Token![async](method.sig.span()));
+                method.attrs.retain(|attr| !is_maybe_async_attr(attr));
+            }
+        }
+    }
+
+    quote! {
+        #[cfg(not(feature = "async"))]
+        #impl_item
+
+        #[cfg(feature = "async")]
+        #[async_trait::async_trait]
+        #async_impl_item
+    }
+    .into()
+}
+
+/// Makes a method or every method of a trait `async`, if the `async` feature is enabled.
+///
+/// Requires the `async-trait` crate as a dependency whenever this attribute is used on a trait
+/// definition or trait implementation.
+#[proc_macro_attribute]
+pub fn maybe_async(_attr: TokenStream, item: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(item as Item);
+
+    match input {
+        Item::Fn(func) => add_async_to_fn(func),
+        Item::Trait(trait_item) => add_async_to_trait(trait_item),
+        Item::Impl(impl_item) => add_async_to_impl(impl_item),
+        Item::Verbatim(verbatim) => {
+            // This case handles unexpected verbatim content, like doc comments
+            quote! {
+                #verbatim
+            }
+            .into()
+        }
+        other => {
+            let item_type = format!("{:?}", other);
+            let error_msg = format!(
+                "#[maybe_async] can only be used on functions, traits, or impl blocks, not on: {}",
+                item_type
+            );
+            quote! {
+                compile_error!(#error_msg);
+            }
+            .into()
+        }
+    }
+}
+
+/// Awaits, if the `async` feature is enabled.
+#[proc_macro]
+pub fn maybe_await(input: TokenStream) -> TokenStream {
+    let expr = parse_macro_input!(input as Expr);
+    let quoted = quote! {
+        {
+            #[cfg(not(feature = "async"))]
+            {
+                #expr
+            }
+
+            #[cfg(feature = "async")]
+            {
+                #expr.await
+            }
+        }
+    };
+
+    quoted.into()
+}
+
+/// Awaits, if the `async` feature is enabled, uses `tokio::Runtime::block_on()` otherwise
+///
+/// Requires the `tokio` crate as a dependecy with `rt-core` or `rt-threaded` to build.
+#[proc_macro]
+pub fn await_or_block(expr: TokenStream) -> TokenStream {
+    let expr = parse_macro_input!(expr as Expr);
+    let quoted = quote! {
+        {
+            #[cfg(not(feature = "async"))]
+            {
+                tokio::runtime::Builder::new_current_thread().enable_all().build().unwrap().block_on(#expr)
+            }
+
+            #[cfg(feature = "async")]
+            {
+                #expr.await
+            }
+        }
+    };
+
+    quoted.into()
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_async_trait() {
+        let t = trybuild::TestCases::new();
+        t.pass("tests/sync.rs");
+    }
+}

dlc-macros/tests/maybe_async.rs

@@ -0,0 +1,27 @@
+use dlc_macros::*;
+
+#[maybe_async]
+trait TestTrait {
+    fn test_method(&self) -> Result<(), std::io::Error>;
+}
+
+struct TestStruct;
+
+#[maybe_async]
+impl TestTrait for TestStruct {
+    fn test_method(&self) -> Result<(), std::io::Error> {
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_sync_implementation() {
+        let test_struct = TestStruct;
+        let test = maybe_await!(test_struct.test_method());
+        assert!(test.is_ok());
+    }
+}

dlc-macros/tests/sync.rs

@@ -0,0 +1,20 @@
+use dlc_macros::maybe_async;
+
+/// Documentation
+#[maybe_async]
+pub trait Example {
+    /// Documentation
+    #[maybe_async]
+    fn example_fn(&self);
+}
+
+struct Test;
+
+impl Example for Test {
+    fn example_fn(&self) {}
+}
+
+fn main() {
+    let test = Test;
+    test.example_fn();
+}

dlc-manager/Cargo.toml

@@ -14,19 +14,22 @@ std = ["dlc/std", "dlc-messages/std", "dlc-trie/std", "bitcoin/std", "lightning/
 fuzztarget = ["rand_chacha"]
 parallel = ["dlc-trie/parallel"]
 use-serde = ["serde", "dlc/use-serde", "dlc-messages/use-serde", "dlc-trie/use-serde"]
+async = ["dep:async-trait"]
 
 [dependencies]
-async-trait = "0.1.50"
+async-trait = { version = "0.1.50", optional = true }
 bitcoin = { version = "0.32.2", default-features = false }
 dlc = { version = "0.7.0", default-features = false, path = "../dlc" }
 dlc-messages = { version = "0.7.0", default-features = false, path = "../dlc-messages" }
 dlc-trie = { version = "0.7.0", default-features = false, path = "../dlc-trie" }
+dlc-macros = { version = "0.1.0", path = "../dlc-macros" }
 hex = { package = "hex-conservative", version = "0.1" }
 lightning = { version = "0.0.125", default-features = false, features = ["grind_signatures"] }
 log = "0.4.14"
 rand_chacha = {version = "0.3.1", optional = true}
 secp256k1-zkp = {version = "0.11.0"}
 serde = {version = "1.0", optional = true}
+# bdk-macros = "0.6.0"
 
 [dev-dependencies]
 bitcoin-rpc-provider = {path = "../bitcoin-rpc-provider"}

dlc-manager/src/lib.rs

@@ -12,6 +12,7 @@
 #![deny(unused_imports)]
 #![deny(missing_docs)]
 
+#[cfg(feature = "async")]
 extern crate async_trait;
 extern crate bitcoin;
 extern crate dlc;
@@ -44,6 +45,7 @@ use channel::signed_channel::{SignedChannel, SignedChannelStateType};
 use channel::Channel;
 use contract::PreClosedContract;
 use contract::{offered_contract::OfferedContract, signed_contract::SignedContract, Contract};
+use dlc_macros::maybe_async;
 use dlc_messages::oracle_msgs::{OracleAnnouncement, OracleAttestation};
 use dlc_messages::ser_impls::{read_address, write_address};
 use error::Error;
@@ -225,13 +227,17 @@ pub trait Storage {
     fn get_chain_monitor(&self) -> Result<Option<ChainMonitor>, Error>;
 }
 
+#[allow(missing_docs)]
 /// Oracle trait provides access to oracle information.
+#[maybe_async]
 pub trait Oracle {
     /// Returns the public key of the oracle.
     fn get_public_key(&self) -> XOnlyPublicKey;
+    #[maybe_async]
     /// Returns the announcement for the event with the given id if found.
     fn get_announcement(&self, event_id: &str) -> Result<OracleAnnouncement, Error>;
     /// Returns the attestation for the event with the given id if found.
+    #[maybe_async]
     fn get_attestation(&self, event_id: &str) -> Result<OracleAttestation, Error>;
 }