fetch-metadata: remove tokio

Cargo.lock

@@ -10635,7 +10635,6 @@ dependencies = [
  "subxt-metadata",
  "syn 2.0.77",
  "thiserror",
- "tokio",
 ]
 
 [[package]]
@@ -10699,6 +10698,7 @@ name = "subxt-macro"
 version = "0.37.0"
 dependencies = [
  "darling 0.20.10",
+ "futures",
  "parity-scale-codec",
  "polkadot-sdk",
  "proc-macro-error2",

codegen/Cargo.toml

@@ -13,7 +13,7 @@ description = "Generate an API for interacting with a substrate node from FRAME
 
 [features]
 default = []
-fetch-metadata = ["dep:jsonrpsee", "dep:tokio", "dep:frame-metadata"]
+fetch-metadata = ["dep:jsonrpsee", "dep:frame-metadata"]
 web = ["jsonrpsee?/async-wasm-client", "jsonrpsee?/client-web-transport", "getrandom/js"]
 
 [dependencies]
@@ -25,9 +25,8 @@ quote = { workspace = true }
 syn = { workspace = true }
 scale-info = { workspace = true }
 subxt-metadata = { workspace = true }
-jsonrpsee = { workspace = true, features = ["async-client", "client-ws-transport-tls", "http-client"], optional = true }
+jsonrpsee = { workspace = true, features = ["ws-client", "http-client"], optional = true }
 hex = { workspace = true, features = ["std"] }
-tokio = { workspace = true, features = ["rt-multi-thread"], optional = true }
 thiserror = { workspace = true }
 scale-typegen = { workspace = true }
 

codegen/src/fetch_metadata.rs

@@ -7,11 +7,7 @@
 use crate::error::FetchMetadataError;
 use codec::{Decode, Encode};
 use jsonrpsee::{
-    async_client::ClientBuilder,
-    client_transport::ws::WsTransportClientBuilder,
-    core::client::{ClientT, Error},
-    http_client::HttpClientBuilder,
-    rpc_params,
+    core::client::ClientT, http_client::HttpClientBuilder, rpc_params, ws_client::WsClientBuilder,
 };
 use std::time::Duration;
 
@@ -60,23 +56,6 @@ pub fn fetch_metadata_from_file_blocking(
     Ok(bytes)
 }
 
-/// Returns the metadata bytes from the provided URL, blocking the current thread.
-pub fn fetch_metadata_from_url_blocking(
-    url: Url,
-    version: MetadataVersion,
-) -> Result<Vec<u8>, FetchMetadataError> {
-    tokio_block_on(fetch_metadata_from_url(url, version))
-}
-
-// Block on some tokio runtime for sync contexts
-fn tokio_block_on<T, Fut: std::future::Future<Output = T>>(fut: Fut) -> T {
-    tokio::runtime::Builder::new_multi_thread()
-        .enable_all()
-        .build()
-        .unwrap()
-        .block_on(fut)
-}
-
 /// Returns the metadata bytes from the provided URL.
 pub async fn fetch_metadata_from_url(
     url: Url,
@@ -95,15 +74,11 @@ async fn fetch_metadata_ws(
     url: Url,
     version: MetadataVersion,
 ) -> Result<Vec<u8>, FetchMetadataError> {
-    let (sender, receiver) = WsTransportClientBuilder::default()
-        .build(url)
-        .await
-        .map_err(|e| Error::Transport(e.into()))?;
-
-    let client = ClientBuilder::default()
+    let client = WsClientBuilder::new()
         .request_timeout(Duration::from_secs(180))
         .max_buffer_capacity_per_subscription(4096)
-        .build_with_tokio(sender, receiver);
+        .build(url)
+        .await?;
 
     fetch_metadata(client, version).await
 }

macro/Cargo.toml

@@ -29,6 +29,7 @@ quote = { workspace = true }
 subxt-codegen = { workspace = true, features = ["fetch-metadata"] }
 scale-typegen = { workspace = true }
 polkadot-sdk = { workspace = true, optional = true, features = ["sp-io", "sc-executor-common", "sp-state-machine", "sp-maybe-compressed-blob", "sc-executor"] }
+futures = { workspace = true, features = ["executor"] }
 
 [lints]
 workspace = true

macro/src/lib.rs

@@ -17,7 +17,7 @@ use scale_typegen::typegen::{
 };
 use subxt_codegen::{
     fetch_metadata::{
-        fetch_metadata_from_file_blocking, fetch_metadata_from_url_blocking, MetadataVersion, Url,
+        fetch_metadata_from_file_blocking, fetch_metadata_from_url, MetadataVersion, Url,
     },
     CodegenBuilder, CodegenError, Metadata,
 };
@@ -256,10 +256,13 @@ fn fetch_metadata(args: &RuntimeMetadataArgs) -> Result<subxt_codegen::Metadata,
                 false => MetadataVersion::Latest,
             };
 
-            fetch_metadata_from_url_blocking(url, version)
-                .map_err(CodegenError::from)
-                .and_then(|b| subxt_codegen::Metadata::decode(&mut &*b).map_err(Into::into))
-                .map_err(|e| e.into_compile_error())?
+            futures::executor::block_on(async {
+                fetch_metadata_from_url(url, version)
+                    .await
+                    .map_err(CodegenError::from)
+                    .and_then(|b| subxt_codegen::Metadata::decode(&mut &*b).map_err(Into::into))
+                    .map_err(|e| e.into_compile_error())
+            })?
         }
         #[cfg(feature = "runtime-path")]
         (None, None) => {