Add a quick and dirty bench

ledger/benches/u8_vec_resize.rs

@@ -0,0 +1,93 @@
+#![feature(test)]
+extern crate test;
+
+use solana_ledger::shred::SHRED_PAYLOAD_SIZE;
+use test::Bencher;
+
+const VAL: u8 = 225;
+const NUM_VECS: usize = 1000;
+
+#[bench]
+fn bench_allocate_vec_250(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vec = vec![VAL; 250];
+    });
+}
+
+#[bench]
+fn bench_allocate_and_resize_vec_250(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vec = vec![VAL; 250];
+        vec.resize(SHRED_PAYLOAD_SIZE, 0);
+    });
+}
+
+#[bench]
+fn bench_allocate_vec_500(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vec = vec![VAL; 500];
+    });
+}
+
+#[bench]
+fn bench_allocate_and_resize_vec_500(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vec = vec![VAL; 500];
+        vec.resize(SHRED_PAYLOAD_SIZE, 0);
+    });
+}
+
+#[bench]
+fn bench_allocate_vec_750(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vec = vec![VAL; 750];
+    });
+}
+
+#[bench]
+fn bench_allocate_and_resize_vec_750(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vec = vec![VAL; 750];
+        vec.resize(SHRED_PAYLOAD_SIZE, 0);
+    });
+}
+
+#[bench]
+fn bench_allocate_vec_1000(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vec = vec![VAL; 1000];
+    });
+}
+
+#[bench]
+fn bench_allocate_and_resize_vec_1000(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vec = vec![VAL; 1000];
+        vec.resize(SHRED_PAYLOAD_SIZE, 0);
+    });
+}
+
+#[bench]
+fn bench_allocate_1000_vec_500(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let vecs: Vec<Vec<u8>> = (0..NUM_VECS)
+            .map(|_| {
+                vec![VAL; 500]
+            })
+            .collect();
+    });
+}
+
+#[bench]
+fn bench_allocate_and_resize_1000_vec_500(bencher: &mut Bencher) {
+    bencher.iter(|| {
+        let mut vecs: Vec<Vec<u8>> = (0..NUM_VECS)
+            .map(|_| {
+                vec![VAL; 500]
+            })
+            .collect();
+        for i in 0..NUM_VECS {
+            vecs[i].resize(SHRED_PAYLOAD_SIZE, 0);
+        }
+    });
+}