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Sled Storage

SledStorage is currently the representative persistent data storage for GlueSQL. As the name suggests, it's a storage option based on the Sled key-value embedded database built in Rust (Sled on Github).

SledStorage can only be used in a Rust environment. It is the only storage among those currently supported by GlueSQL that implements all Store traits, from non-clustered indexes to transactions. If you're looking for a basic storage to handle and store data in a Rust environment, SledStorage is an excellent choice.

How to use​

You can simply create a SledStorage instance using a path, as shown below:

use {
    gluesql::{prelude::Glue, sled_storage::SledStorage},
    sled_storage::sled,
    std::convert::TryFrom,
};

fn main() {
    let storage = SledStorage::new("data/temp").unwrap();
    let mut glue = Glue::new(storage);

    let sqls = "
        CREATE TABLE Glue (id INTEGER);
        INSERT INTO Glue VALUES (100), (200);
    ";

    glue.execute(sqls).unwrap();
}

If you want to use the Sled that SledStorage uses directly with a specific configuration, you can do so as follows:

let config = sled::Config::default()
    .path("data/using_config")
    .temporary(true)
    .mode(sled::Mode::HighThroughput);

let storage = SledStorage::try_from(config).unwrap();
let mut glue = Glue::new(storage);

Things to Know About Transactions​

The implementation of transactions in SledStorage manages not only data but also indexes and schema information based on snapshots. For example, if you use the following commands:

BEGIN;

CREATE TABLE Foo;
INSERT INTO Foo VALUES (1);

ROLLBACK;

The above usage will result in a rollback of even the contents regarding the Foo table. The transaction isolation level is repeatable read (snapshot isolation).

By default, there is a timeout for Transactions. The default is set to one hour, but you can modify the value or remove the timeout if desired.

storage.set_transaction_timeout(Some(1000)); // 1 sec
storage.set_transaction_timeout(None); // no timeout

Summary​

If you're looking for a storage to handle data for general purposes in a Rust environment, SledStorage would be your go-to choice. It offers all the necessary features of a database system, such as managing non-clustered indexes, handling transactions, and maintaining persistent storage. Additionally, its snapshot-based transaction model ensures consistency and reliability, making it an excellent choice for applications requiring persistent data storage.