Benchmark adding 500 contacts from address book

Cargo.toml

@@ -103,6 +103,10 @@ required-features = ["repl"]
 name = "create_account"
 harness = false
 
+[[bench]]
+name = "contacts"
+harness = false
+
 [features]
 default = []
 internals = []

benches/contacts.rs

@@ -0,0 +1,30 @@
+use async_std::task::block_on;
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use deltachat::contact::Contact;
+use deltachat::context::Context;
+use tempfile::tempdir;
+
+async fn address_book_benchmark(n: u32) {
+    let dir = tempdir().unwrap();
+    let dbfile = dir.path().join("db.sqlite");
+    let id = 100;
+    let context = Context::new("FakeOS".into(), dbfile.into(), id)
+        .await
+        .unwrap();
+
+    let book = (0..n)
+        .map(|i| format!("Name {}\naddr{}@example.org\n", i, i))
+        .collect::<Vec<String>>()
+        .join("");
+
+    Contact::add_address_book(&context, book).await.unwrap();
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    c.bench_function("create 500 contacts", |b| {
+        b.iter(|| block_on(async { address_book_benchmark(black_box(500)).await }))
+    });
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);