tsp_sdk: reuse reqwest clients to reduce HTTP/DID resolution overhead

tsp_sdk/src/http_client.rs

@@ -0,0 +1,40 @@
+#[cfg(feature = "resolve")]
+use once_cell::sync::OnceCell;
+
+#[cfg(feature = "resolve")]
+#[derive(Debug)]
+pub(crate) struct ReqwestClientError {
+    pub(crate) context: &'static str,
+    pub(crate) source: reqwest::Error,
+}
+
+#[cfg(feature = "resolve")]
+pub(crate) fn reqwest_client() -> Result<&'static reqwest::Client, ReqwestClientError> {
+    static CLIENT: OnceCell<reqwest::Client> = OnceCell::new();
+
+    CLIENT.get_or_try_init(|| {
+        let client = reqwest::Client::builder();
+
+        #[cfg(feature = "use_local_certificate")]
+        let client = {
+            #[cfg(feature = "async")]
+            tracing::warn!("Using local root CA! (should only be used for local testing)");
+
+            let cert = reqwest::Certificate::from_pem(include_bytes!(
+                "../../examples/test/root-ca.pem"
+            ))
+            .map_err(|e| ReqwestClientError {
+                context: "Local root CA",
+                source: e,
+            })?;
+
+            client.add_root_certificate(cert)
+        };
+
+        client.build().map_err(|e| ReqwestClientError {
+            context: "Client build error",
+            source: e,
+        })
+    })
+}
+

tsp_sdk/src/lib.rs

@@ -94,6 +94,8 @@ pub mod crypto;
 /// Defines several common data structures, traits and error types that are used throughout the project.
 pub mod definitions;
 mod error;
+#[cfg(feature = "resolve")]
+mod http_client;
 mod store;
 
 /// Contains code for handling *verified identifiers* and identities.

tsp_sdk/src/transport/http.rs

@@ -20,23 +20,11 @@ pub(crate) const SCHEME_WS: &str = "ws";
 pub(crate) const SCHEME_WSS: &str = "wss";
 
 pub(crate) async fn send_message(tsp_message: &[u8], url: &Url) -> Result<(), TransportError> {
-    let client = reqwest::Client::builder();
-
-    #[cfg(feature = "use_local_certificate")]
-    let cert = {
-        warn!("Using local root CA! (should only be used for local testing)");
-        let cert = include_bytes!("../../../examples/test/root-ca.pem");
-        reqwest::Certificate::from_pem(cert).unwrap()
-    };
-
-    #[cfg(feature = "use_local_certificate")]
-    let client = client.add_root_certificate(cert);
-
     let url = url.clone();
+    let client = crate::http_client::reqwest_client()
+        .map_err(|e| TransportError::Http(e.context.to_string(), e.source))?;
 
     let response = client
-        .build()
-        .map_err(|e| TransportError::Http("Client build error".to_string(), e))?
         .post(url.clone())
         .body(tsp_message.to_vec())
         .send()

tsp_sdk/src/vid/did/web.rs

@@ -173,21 +173,10 @@ pub async fn resolve(id: &str, parts: Vec<&str>) -> Result<Vid, VidError> {
     {
         let url = resolve_url(&parts)?;
 
-        let client = reqwest::Client::builder();
-
-        #[cfg(feature = "use_local_certificate")]
-        let cert = {
-            tracing::warn!("Using local root CA! (should only be used for local testing)");
-            reqwest::Certificate::from_pem(include_bytes!("../../../../examples/test/root-ca.pem"))
-                .unwrap()
-        };
-
-        #[cfg(feature = "use_local_certificate")]
-        let client = client.add_root_certificate(cert);
+        let client = crate::http_client::reqwest_client()
+            .map_err(|e| VidError::Http(e.context.to_string(), e.source))?;
 
         let response = client
-            .build()
-            .map_err(|e| VidError::Http("Client build error".to_string(), e))?
             .get(url.as_ref())
             .send()
             .await