A generic connection pool for Rust.
Opening a new database connection every time one is needed is both inefficient and can lead to resource exhaustion under high traffic conditions. A connection pool maintains a set of open connections to a database, handing them out for repeated use.
r2d2 is agnostic to the connection type it is managing. Implementors of the
ManageConnection trait provide the database-specific logic to create and
check the health of connections.
A (possibly not exhaustive) list of adaptors for different backends:
| Backend | Adaptor Crate |
|---|---|
| rust-postgres | r2d2-postgres |
| redis-rs | use r2d2 feature of redis-rs |
| rust-memcache | r2d2-memcache |
| rust-mysql-simple | r2d2-mysql |
| rusqlite | r2d2-sqlite |
| rsfbclient | r2d2-firebird |
| rusted-cypher | r2d2-cypher |
| diesel | diesel::r2d2 (docs) |
| couchdb | r2d2-couchdb |
| mongodb (archived) use official mongodb driver instead |
r2d2-mongodb (deprecated: official driver handles pooling internally) |
| odbc | r2d2-odbc |
| jfs | r2d2-jfs |
| oracle | r2d2-oracle |
| ldap3 | r2d2-ldap |
| duckdb-rs | use r2d2 feature of duckdb-rs |
Using an imaginary "foodb" database.
use std::thread;
extern crate r2d2;
extern crate r2d2_foodb;
fn main() {
let manager = r2d2_foodb::FooConnectionManager::new("localhost:1234");
let pool = r2d2::Pool::builder()
.max_size(15)
.build(manager)
.unwrap();
for _ in 0..20 {
let pool = pool.clone();
thread::spawn(move || {
let conn = pool.get().unwrap();
// use the connection
// it will be returned to the pool when it falls out of scope.
})
}
}Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.