Skip transaction simulation on retries

src/bin/sys-lend.rs

@@ -1002,10 +1002,6 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                     &vec![signer],
                 )?
             };
-            let simulation_result = send_rpc_client.simulate_transaction(&transaction)?.value;
-            if simulation_result.err.is_some() {
-                return Err(format!("Simulation failure: {simulation_result:?}").into());
-            }
 
             /*
             println!(
@@ -1016,7 +1012,6 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
             */
 
             let signature = transaction.signatures[0];
-
             let msg = match cmd {
                 Command::Deposit => format!(
                     "Depositing {} from {} into {} via {}",
@@ -1040,6 +1035,11 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                 ),
             };
 
+            let simulation_result = send_rpc_client.simulate_transaction(&transaction)?.value;
+            if simulation_result.err.is_some() {
+                return Err(format!("Simulation failure: {simulation_result:?}").into());
+            }
+
             if !send_transaction_until_expired(
                 &send_rpc_client,
                 &transaction,

src/lib.rs

@@ -23,18 +23,27 @@ pub fn app_version() -> String {
     })
 }
 
+// Assumes `transaction` has already been signed and simulated...
 pub fn send_transaction_until_expired(
     rpc_client: &RpcClient,
     transaction: &impl SerializableTransaction,
     last_valid_block_height: u64,
 ) -> bool {
-    use std::{
-        thread::sleep,
-        time::{Duration, Instant},
+    use {
+        solana_client::rpc_config::RpcSendTransactionConfig,
+        std::{
+            thread::sleep,
+            time::{Duration, Instant},
+        },
     };
 
     let mut last_send_attempt = None;
 
+    let config = RpcSendTransactionConfig {
+        skip_preflight: true,
+        ..RpcSendTransactionConfig::default()
+    };
+
     loop {
         if last_send_attempt.is_none()
             || Instant::now()
@@ -61,7 +70,7 @@ pub fn send_transaction_until_expired(
                 "Sending transaction {} [{valid_msg}]",
                 transaction.get_signature()
             );
-            if let Err(err) = rpc_client.send_transaction(transaction) {
+            if let Err(err) = rpc_client.send_transaction_with_config(transaction, config) {
                 println!("Transaction failed to send: {err:?}");
             }
             last_send_attempt = Some(Instant::now());