Make api/rpc interfaces no_std compatible (#384)

* make rpc interface no-std compatible

* move feature flag below doc

Cargo.toml

@@ -25,9 +25,10 @@ log = { version = "0.4.14", default-features = false }
 serde = { version = "1.0.136", default-features = false, features = ["derive"] }
 serde_json = { version = "1.0.79", default-features = false }
 
+#FIXME: convert back to thiserror once possible #317
+thiserror = { version = "1.0", package = "thiserror-core", default-features = false }
+
 # crates.io std only
-primitive-types = { version = "0.12.1", optional = true, features = ["codec"] }
-thiserror = { version = "1.0.30", optional = true }
 url = { version = "2.0.0", optional = true }
 
 # websocket dependent features
@@ -70,9 +71,8 @@ std = [
     "log/std",
     "serde/std",
     "serde_json/std",
+    "thiserror/std",
     # crates.io std only
-    "primitive-types",
-    "thiserror",
     "url",
     # substrate no_std
     "frame-metadata/std",

compose-macros/src/lib.rs

@@ -21,9 +21,7 @@
 
 // re-export for macro resolution
 pub use ac_primitives as primitives;
-#[cfg(feature = "std")]
 pub use codec;
-#[cfg(feature = "std")]
 pub use log;
 pub use rpc::*;
 pub use sp_core;
@@ -98,7 +96,6 @@ macro_rules! compose_extrinsic_offline {
 /// * 'args' - Optional sequence of arguments of the call. They are not checked against the metadata.
 /// As of now the user needs to check himself that the correct arguments are supplied.
 #[macro_export]
-#[cfg(feature = "std")]
 macro_rules! compose_extrinsic {
 	($api: expr,
 	$module: expr,

primitives/src/rpc_params.rs

@@ -42,7 +42,6 @@ impl RpcParams {
 	}
 
 	/// Insert a plain value into the builder.
-	#[cfg(feature = "std")]
 	pub fn insert<P: Serialize>(&mut self, value: P) -> Result<()> {
 		self.0.insert(value)
 	}
@@ -145,6 +144,13 @@ impl ParamsBuilder {
 		Ok(())
 	}
 
+	/// Insert a plain value into the builder with heap allocation. If available,
+	/// use the more efficient std version.
+	#[cfg(not(feature = "std"))]
+	pub(crate) fn insert<P: Serialize>(&mut self, value: P) -> Result<()> {
+		self.insert_with_allocation(value)
+	}
+
 	/// Insert a plain value into the builder with heap allocation. For better performance,
 	/// use the std version, if possible.
 	pub(crate) fn insert_with_allocation<P: Serialize>(&mut self, value: P) -> Result<()> {

src/lib.rs

@@ -16,12 +16,16 @@
 */
 #![cfg_attr(not(feature = "std"), no_std)]
 #![feature(assert_matches)]
+#![feature(error_in_core)]
+
+extern crate alloc;
 
 pub use ac_compose_macros::*;
 pub use ac_node_api::*;
 pub use ac_primitives::*;
 pub use utils::*;
 
+pub mod rpc;
 pub mod utils;
 
 // std only features:
@@ -33,5 +37,3 @@ pub use api::*;
 pub mod api;
 #[cfg(feature = "std")]
 pub mod extrinsic;
-#[cfg(feature = "std")]
-pub mod rpc;

src/rpc/error.rs

@@ -15,33 +15,33 @@
 
 */
 
-use std::sync::mpsc::SendError;
+use alloc::{boxed::Box, string::String};
 
 pub type Result<T> = core::result::Result<T, Error>;
 
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
 	#[error("Serde json error: {0}")]
-	Serde(#[from] serde_json::error::Error),
+	Serde(serde_json::error::Error),
 	#[error("mpsc send Error: {0}")]
 	Send(String),
 	#[error("Could not convert to valid Url: {0}")]
-	Url(#[from] url::ParseError),
+	Url(String),
 	#[error("ChannelReceiveError, sender is disconnected: {0}")]
-	ChannelDisconnected(#[from] sp_std::sync::mpsc::RecvError),
+	ChannelDisconnected(String),
 	#[error("Failure during thread creation: {0}")]
-	Io(#[from] std::io::Error),
+	Io(String),
 	#[error("Exceeded maximum amount of connections")]
 	ConnectionAttemptsExceeded,
 	#[error("Websocket Connection was closed unexpectedly")]
 	ConnectionClosed,
 	#[error(transparent)]
-	Client(#[from] Box<dyn std::error::Error + Send + Sync + 'static>),
+	Client(#[from] Box<dyn core::error::Error + Send + Sync + 'static>),
 }
 
-impl From<SendError<String>> for Error {
-	fn from(error: SendError<String>) -> Self {
-		Self::Send(error.0)
+impl From<serde_json::error::Error> for Error {
+	fn from(error: serde_json::error::Error) -> Self {
+		Self::Serde(error)
 	}
 }
 
@@ -58,3 +58,35 @@ impl From<tungstenite::Error> for Error {
 		Self::Client(Box::new(error))
 	}
 }
+
+#[cfg(feature = "std")]
+pub use std_only::*;
+#[cfg(feature = "std")]
+mod std_only {
+	use super::*;
+	use std::sync::mpsc::{RecvError, SendError};
+
+	impl From<SendError<String>> for Error {
+		fn from(error: SendError<String>) -> Self {
+			Self::Send(error.0)
+		}
+	}
+
+	impl From<RecvError> for Error {
+		fn from(error: RecvError) -> Self {
+			Self::ChannelDisconnected(format!("{:?}", error))
+		}
+	}
+
+	impl From<std::io::Error> for Error {
+		fn from(error: std::io::Error) -> Self {
+			Self::Io(format!("{:?}", error))
+		}
+	}
+
+	impl From<url::ParseError> for Error {
+		fn from(error: url::ParseError) -> Self {
+			Self::Io(format!("{:?}", error))
+		}
+	}
+}

src/rpc/mod.rs

@@ -35,6 +35,7 @@ pub mod error;
 pub use error::*;
 
 use ac_primitives::RpcParams;
+use alloc::string::{String, ToString};
 use serde::de::DeserializeOwned;
 
 /// Trait to be implemented by the ws-client for sending rpc requests and extrinsic.

src/utils.rs

@@ -15,11 +15,7 @@
 
 */
 
-#[cfg(not(feature = "std"))]
-extern crate alloc;
-#[cfg(not(feature = "std"))]
 use alloc::{string::String, vec::Vec};
-
 use hex::FromHexError;
 use sp_core::{storage::StorageKey, twox_128, H256};