Move key generation and signing from transaction benchmark

Key generation, signing and verification are not the performance
bottleneck. Something is probably wrong here.

src/bin/client-demo.rs

@@ -4,12 +4,12 @@ fn main() {
     use silk::accountant_stub::AccountantStub;
     use std::time::Instant;
     use std::net::UdpSocket;
-    use silk::event::{generate_keypair, get_pubkey};
+    use silk::event::{generate_keypair, get_pubkey, sign_transaction_data};
 
     let addr = "127.0.0.1:8000";
     let send_addr = "127.0.0.1:8001";
     let socket = UdpSocket::bind(send_addr).unwrap();
-    let mut acc = AccountantStub::new(addr, socket);
+    let acc = AccountantStub::new(addr, socket);
     let alice_keypair = generate_keypair();
     let alice_pubkey = get_pubkey(&alice_keypair);
     let txs = 2_000;
@@ -19,13 +19,30 @@ fn main() {
     assert_eq!(acc.get_balance(&alice_pubkey).unwrap(), txs);
     println!("Done.");
 
+    let one = 1;
+    println!("Signing transactions...");
+    let now = Instant::now();
+    let sigs = (0..txs).map(|_| {
+        let rando_keypair = generate_keypair();
+        let rando_pubkey = get_pubkey(&rando_keypair);
+        let sig = sign_transaction_data(&one, &alice_keypair, &rando_pubkey);
+        (rando_pubkey, sig)
+    });
+    let duration = now.elapsed();
+    let ns = duration.as_secs() * 1_000_000_000 + duration.subsec_nanos() as u64;
+    let bsps = txs as f64 / ns as f64;
+    let nsps = ns as f64 / txs as f64;
+    println!(
+        "Done. {} billion signatures per second, {}ns per signature",
+        bsps, nsps
+    );
+
     println!("Transferring 1 unit {} times...", txs);
     let now = Instant::now();
     let mut sig = sig;
-    for _ in 0..txs {
-        let bob_keypair = generate_keypair();
-        let bob_pubkey = get_pubkey(&bob_keypair);
-        sig = acc.transfer(1, &alice_keypair, bob_pubkey).unwrap();
+    for (k, s) in sigs {
+        acc.transfer_signed(alice_pubkey, k, one, s).unwrap();
+        sig = s;
     }
     println!("Waiting for last transaction to be confirmed...",);
     acc.wait_on_signature(&sig).unwrap();