benches: add sqlite_fetch_all benchmark

adapted code from https://github.com/launchbadge/sqlx/issues/266#issuecomment-921722399

.gitignore

@@ -9,3 +9,7 @@ target/
 
 # Environment
 .env
+
+# Shared-memory and WAL files created by SQLite.
+*-shm
+*-wal

Cargo.lock

@@ -2419,6 +2419,7 @@ dependencies = [
 name = "sqlx-bench"
 version = "0.1.0"
 dependencies = [
+ "chrono",
  "criterion",
  "dotenv",
  "once_cell",

sqlx-bench/Cargo.toml

@@ -33,15 +33,23 @@ runtime-tokio-rustls = [
 ]
 
 postgres = ["sqlx/postgres"]
+sqlite = ["sqlx/sqlite"]
 
 [dependencies]
 criterion = "0.3.3"
 dotenv = "0.15.0"
 once_cell = "1.4"
-sqlx = { version = "0.6", path = "../", default-features = false }
+sqlx = { version = "0.6", path = "../", default-features = false, features = ["macros"] }
 sqlx-rt = { version = "0.6", path = "../sqlx-rt", default-features = false }
 
+chrono = "0.4.19"
+
 [[bench]]
 name = "pg_pool"
 harness = false
 required-features = ["postgres"]
+
+[[bench]]
+name = "sqlite_fetch_all"
+harness = false
+required-features = ["sqlite"]

sqlx-bench/benches/sqlite_fetch_all.rs

@@ -0,0 +1,45 @@
+use sqlx::{Connection, Executor};
+
+use std::time::Instant;
+
+#[derive(sqlx::FromRow)]
+struct Test {
+    id: i32,
+}
+
+fn main() -> sqlx::Result<()> {
+    sqlx_rt::block_on(async {
+        let mut conn = sqlx::SqliteConnection::connect("sqlite://test.db?mode=rwc").await?;
+        let delete_sql = "DROP TABLE IF EXISTS test";
+        conn.execute(delete_sql).await?;
+
+        let create_sql = "CREATE TABLE IF NOT EXISTS test (id INTEGER PRIMARY KEY NOT NULL)";
+        conn.execute(create_sql).await?;
+
+        let mut tx = conn.begin().await?;
+        for entry in 0i32..100000 {
+            sqlx::query("INSERT INTO test (id) VALUES ($1)")
+                .bind(entry)
+                .execute(&mut tx)
+                .await?;
+        }
+        tx.commit().await?;
+
+        for _ in 0..10i8 {
+            let start = chrono::Utc::now();
+
+            println!(
+                "total: {}",
+                sqlx::query!("SELECT id from test")
+                    .fetch_all(&mut conn)
+                    .await?
+                    .len()
+            );
+
+            let elapsed = chrono::Utc::now() - start;
+            println!("elapsed {}", elapsed);
+        }
+
+        Ok(())
+    })
+}