Adds micro benchmark to all builders using basic api

.gitignore

@@ -3,3 +3,4 @@
 
 /Cargo.lock
 .DS_Store
+output.txt

benches/basic_api.rs

@@ -0,0 +1,145 @@
+#![feature(test)]
+/// To run this benchmark you must use the nightly version:
+/// rustup override set nightly
+extern crate test;
+
+#[cfg(test)]
+mod any_feature {
+  use sql_query_builder as sql;
+  use test::{black_box, Bencher};
+
+  #[bench]
+  fn alter_table_builder(b: &mut Bencher) {
+    b.iter(|| {
+      sql::AlterTable::new()
+        .alter_table(black_box("users"))
+        .add(black_box("COLUMN id serial primary key"))
+        .add(black_box("COLUMN login varchar(40) not null"))
+        .drop(black_box("CONSTRAINT users_login_key"))
+        .as_string()
+    })
+  }
+
+  #[bench]
+  fn create_table_builder(b: &mut Bencher) {
+    b.iter(|| {
+      sql::CreateTable::new()
+        .create_table(black_box("users"))
+        .column(black_box("id serial primary key"))
+        .column(black_box("login varchar(40) not null"))
+        .constraint(black_box("users_login_key unique(login)"))
+        .as_string()
+    })
+  }
+
+  #[bench]
+  fn delete_builder(b: &mut Bencher) {
+    b.iter(|| sql::DropTable::new().drop_table(black_box("users")).as_string())
+  }
+
+  #[bench]
+  fn drop_table_builder(b: &mut Bencher) {
+    b.iter(|| {
+      sql::Delete::new()
+        .delete_from(black_box("users"))
+        .where_clause(black_box("id = $1"))
+        .as_string()
+    })
+  }
+
+  #[bench]
+  fn insert_builder(b: &mut Bencher) {
+    b.iter(|| {
+      sql::Insert::new()
+        .insert_into(black_box("users (login, name)"))
+        .values(black_box("('foo', 'Foo')"))
+        .values(black_box("('bar', 'Bar')"))
+        .as_string()
+    })
+  }
+
+  #[bench]
+  fn select_builder(b: &mut Bencher) {
+    b.iter(|| {
+      sql::Select::new()
+        .select(black_box("*"))
+        .from(black_box("users"))
+        .inner_join(black_box("orders ON users.login = orders.login"))
+        .where_clause(black_box("user.login = $1"))
+        .order_by(black_box("created_at desc"))
+        .as_string()
+    })
+  }
+
+  #[bench]
+  fn update_builder(b: &mut Bencher) {
+    b.iter(|| {
+      sql::Update::new()
+        .update(black_box("users"))
+        .set(black_box("name = 'Bar'"))
+        .where_clause(black_box("id = $1"))
+        .as_string()
+    })
+  }
+
+  #[bench]
+  fn values_builder(b: &mut Bencher) {
+    b.iter(|| {
+      sql::Values::new()
+        .values(black_box("('foo', 'Foo')"))
+        .values(black_box("('bar', 'Bar')"))
+        .as_string()
+    })
+  }
+}
+
+#[cfg(any(feature = "postgresql", feature = "sqlite"))]
+#[cfg(test)]
+mod postgresql_or_sqlite {
+  use sql_query_builder as sql;
+  use test::{black_box, Bencher};
+
+  #[bench]
+  fn create_index_builder(b: &mut Bencher) {
+    b.iter(|| {
+      sql::CreateIndex::new()
+        .create_index(black_box("users_name_idx"))
+        .on(black_box("users"))
+        .column(black_box("name"))
+        .as_string()
+    })
+  }
+
+  #[bench]
+  fn drop_index_builder(b: &mut Bencher) {
+    b.iter(|| sql::DropIndex::new().drop_index("users_name_idx").as_string())
+  }
+}
+
+#[cfg(not(feature = "sqlite"))]
+#[cfg(test)]
+mod not_sqlite {
+  use sql_query_builder as sql;
+  use test::{black_box, Bencher};
+
+  #[bench]
+  fn transaction_builder(b: &mut Bencher) {
+    b.iter(|| {
+      let insert_foo = sql::Insert::new()
+        .insert_into(black_box("users (login, name)"))
+        .values(black_box("('foo', 'Foo')"));
+
+      let update_foo = sql::Update::new()
+        .update(black_box("users"))
+        .set(black_box("name = 'Bar'"))
+        .where_clause(black_box("login = 'foo'"));
+
+      sql::Transaction::new()
+        .start_transaction(black_box("isolation level serializable"))
+        .insert(insert_foo)
+        .update(update_foo)
+        .commit(black_box("transaction"))
+        .as_string()
+    })
+  }
+}