Factor RPC request mechanism out of RpcClient into *RpcClientRequest

client/src/rpc_client_request.rs

@@ -0,0 +1,81 @@
+use crate::generic_rpc_client_request::GenericRpcClientRequest;
+use crate::rpc_request::{RpcError, RpcRequest};
+use log::*;
+use reqwest;
+use reqwest::header::CONTENT_TYPE;
+use solana_sdk::timing::{DEFAULT_TICKS_PER_SLOT, NUM_TICKS_PER_SECOND};
+use std::thread::sleep;
+use std::time::Duration;
+
+pub struct RpcClientRequest {
+    client: reqwest::Client,
+    url: String,
+}
+
+impl RpcClientRequest {
+    pub fn new(url: String) -> Self {
+        Self {
+            client: reqwest::Client::new(),
+            url,
+        }
+    }
+
+    pub fn new_with_timeout(url: String, timeout: Duration) -> Self {
+        let client = reqwest::Client::builder()
+            .timeout(timeout)
+            .build()
+            .expect("build rpc client");
+
+        Self { client, url }
+    }
+}
+
+impl GenericRpcClientRequest for RpcClientRequest {
+    fn send(
+        &self,
+        request: &RpcRequest,
+        params: Option<serde_json::Value>,
+        mut retries: usize,
+    ) -> Result<serde_json::Value, Box<dyn std::error::Error>> {
+        // Concurrent requests are not supported so reuse the same request id for all requests
+        let request_id = 1;
+
+        let request_json = request.build_request_json(request_id, params);
+
+        loop {
+            match self
+                .client
+                .post(&self.url)
+                .header(CONTENT_TYPE, "application/json")
+                .body(request_json.to_string())
+                .send()
+            {
+                Ok(mut response) => {
+                    let json: serde_json::Value = serde_json::from_str(&response.text()?)?;
+                    if json["error"].is_object() {
+                        Err(RpcError::RpcRequestError(format!(
+                            "RPC Error response: {}",
+                            serde_json::to_string(&json["error"]).unwrap()
+                        )))?
+                    }
+                    return Ok(json["result"].clone());
+                }
+                Err(e) => {
+                    info!(
+                        "make_rpc_request() failed, {} retries left: {:?}",
+                        retries, e
+                    );
+                    if retries == 0 {
+                        Err(e)?;
+                    }
+                    retries -= 1;
+
+                    // Sleep for approximately half a slot
+                    sleep(Duration::from_millis(
+                        500 * DEFAULT_TICKS_PER_SLOT / NUM_TICKS_PER_SECOND,
+                    ));
+                }
+            }
+        }
+    }
+}