Add a few protocol codec benchmarks

Cargo.toml

@@ -36,6 +36,7 @@ uuid = { version = "0.8.1", optional = true }
 matches = "0.1.8"
 tokio = { version = "0.2.0-alpha.4", default-features = false, features = [ "rt-full" ] }
 sqlx-macros = { path = "sqlx-macros/" }
+criterion = "0.3"
 
 [profile.release]
 lto = true
@@ -44,3 +45,8 @@ codegen-units = 1
 [[test]]
 name = "sql-macro-test"
 required-features = ["uuid"]
+
+[[bench]]
+name = "postgres_protocol"
+required-features = ["postgres", "unstable"]
+harness = false

benches/postgres_protocol.rs

@@ -0,0 +1,37 @@
+use sqlx::postgres::protocol::{Bind, DataRow, RowDescription};
+use sqlx::postgres::protocol::{Encode, Decode};
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+
+fn bench(c: &mut Criterion) {
+    c.bench_function("decode_data_row", |b| {
+        b.iter(|| {
+            let _ = DataRow::decode(&black_box(b"\0\x03\0\0\0\x011\0\0\0\x012\0\0\0\x013")[..]);
+        });
+    });
+
+    c.bench_function( "decode_row_description",|b| {
+        b.iter(|| {
+            let _ = RowDescription::decode(&black_box(b"\0\x02user_id\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0number_of_pages\0\0\0\0\0\0\0\0\0\x05\0\0\0\0\0\0\0\0\0")[..]);
+        });
+    });
+
+    c.bench_function("encode_bind", |b| {
+        let mut buf = Vec::new();
+
+        b.iter(|| {
+            black_box(Bind {
+                portal: "__sqlx_portal_5121",
+                statement: "__sqlx_statement_5121",
+                formats: &[1],
+                values_len: 2,
+                values: &[(-1_i8) as _, 0, 0, 0, 1, 0, 0, 0, 25],
+                result_formats: &[1],
+            }).encode(&mut buf);
+
+            buf.clear();
+        });
+    });
+}
+
+criterion_group!(benches, bench);
+criterion_main!(benches);