Add sample_txs function to perf_utils shared crate (#4104)

Shared code between bench-tps and bench-exchange

client/src/lib.rs

@@ -1,6 +1,7 @@
 pub mod client_error;
 mod generic_rpc_client_request;
 pub mod mock_rpc_client_request;
+pub mod perf_utils;
 pub mod rpc_client;
 pub mod rpc_client_request;
 pub mod rpc_request;

client/src/perf_utils.rs

@@ -0,0 +1,76 @@
+use log::*;
+use solana_sdk::client::Client;
+use solana_sdk::timing::duration_as_s;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, RwLock};
+use std::thread::sleep;
+use std::time::{Duration, Instant};
+
+#[derive(Default)]
+pub struct SampleStats {
+    /// Maximum TPS reported by this node
+    pub tps: f32,
+    /// Total time taken for those txs
+    pub elapsed: Duration,
+    /// Total transactions reported by this node
+    pub txs: u64,
+}
+
+pub fn sample_txs<T>(
+    exit_signal: &Arc<AtomicBool>,
+    sample_stats: &Arc<RwLock<Vec<(String, SampleStats)>>>,
+    sample_period: u64,
+    client: &Arc<T>,
+) where
+    T: Client,
+{
+    let mut max_tps = 0.0;
+    let mut total_elapsed;
+    let mut total_txs;
+    let mut now = Instant::now();
+    let start_time = now;
+    let initial_txs = client.get_transaction_count().expect("transaction count");
+    let mut last_txs = initial_txs;
+
+    loop {
+        total_elapsed = start_time.elapsed();
+        let elapsed = now.elapsed();
+        now = Instant::now();
+        let mut txs = client.get_transaction_count().expect("transaction count");
+
+        if txs < last_txs {
+            info!("Expected txs({}) >= last_txs({})", txs, last_txs);
+            txs = last_txs;
+        }
+        total_txs = txs - initial_txs;
+        let sample_txs = txs - last_txs;
+        last_txs = txs;
+
+        let tps = sample_txs as f32 / duration_as_s(&elapsed);
+        if tps > max_tps {
+            max_tps = tps;
+        }
+
+        info!(
+            "Sampler {:9.2} TPS, Transactions: {:6}, Total transactions: {} over {} s",
+            tps,
+            sample_txs,
+            total_txs,
+            total_elapsed.as_secs(),
+        );
+
+        if exit_signal.load(Ordering::Relaxed) {
+            let stats = SampleStats {
+                tps: max_tps,
+                elapsed: total_elapsed,
+                txs: total_txs,
+            };
+            sample_stats
+                .write()
+                .unwrap()
+                .push((client.transactions_addr(), stats));
+            return;
+        }
+        sleep(Duration::from_secs(sample_period));
+    }
+}