v1.17: Allow to create HTTP Sender with custom Client (backport of #33580)

rpc-client/src/http_sender.rs

@@ -47,31 +47,41 @@ impl HttpSender {
     ///
     /// The URL is an HTTP URL, usually for port 8899.
     pub fn new_with_timeout<U: ToString>(url: U, timeout: Duration) -> Self {
-        let mut default_headers = header::HeaderMap::new();
-        default_headers.append(
-            header::HeaderName::from_static("solana-client"),
-            header::HeaderValue::from_str(
-                format!("rust/{}", solana_version::Version::default()).as_str(),
-            )
-            .unwrap(),
-        );
-
-        let client = Arc::new(
+        Self::new_with_client(
+            url,
             reqwest::Client::builder()
-                .default_headers(default_headers)
+                .default_headers(Self::default_headers())
                 .timeout(timeout)
                 .pool_idle_timeout(timeout)
                 .build()
                 .expect("build rpc client"),
-        );
+        )
+    }
 
+    /// Create an HTTP RPC sender.
+    ///
+    /// Most flexible way to create a sender. Pass a created `reqwest::Client`.
+    pub fn new_with_client<U: ToString>(url: U, client: reqwest::Client) -> Self {
         Self {
-            client,
+            client: Arc::new(client),
             url: url.to_string(),
             request_id: AtomicU64::new(0),
             stats: RwLock::new(RpcTransportStats::default()),
         }
     }
+
+    /// Create default headers used by HTTP Sender.
+    pub fn default_headers() -> header::HeaderMap {
+        let mut default_headers = header::HeaderMap::new();
+        default_headers.append(
+            header::HeaderName::from_static("solana-client"),
+            header::HeaderValue::from_str(
+                format!("rust/{}", solana_version::Version::default()).as_str(),
+            )
+            .unwrap(),
+        );
+        default_headers
+    }
 }
 
 struct StatsUpdater<'a> {