nanopool

A fast and tiny asynchronous database pool for PostgreSQL.

The pool is built on top of the Tokio ecosystem to minimize non-Tokio dependencies and maximize performance. It also aims to be easy to use, with a simple API and minimal configuration. The pool has built-in TLS support, and optional features like uuid can be enabled for additional PostgreSQL functionality. It purposely does not support other databases to keep the codebase small and focused.

The pool is backed by a Tokio mpsc channel, which is optimized for fast concurrent access. Database operations are executed using tokio-postgres, which is a high-performance asynchronous PostgreSQL driver. Secure connections to PostgreSQL are supported through the tokio-native-tls crate. The core pool implementation is <200 lines of code, making it lightweight and easy to understand.

Usage

1. Add nanopool to your Cargo.toml:

[dependencies]
nanopool = "1.0"

2. Create and use a connection pool:

use nanopool::{Pool, tls};

// create the pool with TLS support
let tls = tls::configure(tls::TlsMode::Require).unwrap();
let pool_size = 4;
let pool = Pool::new("postgresql://postgres:postgres@localhost/postgres", tls, pool_size).await.unwrap();

// or without TLS support
// let pool = Pool::new("postgresql://postgres:postgres@localhost/postgres", tls::NoTls, pool_size).await.unwrap();

// returns a `tokio_postgres::Client` instance
let client = pool.client().await.unwrap();

// execute a query
let row = client.query_one("SELECT 1 + 2", &[]).await.unwrap();
let sum: i32 = row.get(0);

// the client is automatically returned to the pool when dropped

Optional features

• uuid: Enables support for UUIDs so they can be used in and returned from queries. This feature depends on the uuid crate. These can then be used from your code with nanopool::uuid::Uuid.

Development

Building

To build the library:

cargo build

Testing

To run unit tests:

cargo test

To also run integration tests against a PostgreSQL database:

docker compose -f tests/docker-compose.test.yml up -d
cargo test -- --include-ignored