Setting up embedded SurrealDB with RocksDB backend in Rust

Before we get into the use of SurrealDB from Rust, let's see a very simple example of setting it up as an embedded database.

Depending on the use case you might want a stand-alone running SurrealDB to which you can connect from some external process or you might want a database that does not need a separate process. In this case you might use an in-memory version of SurreealDB, but for my current goal I wanted to have a persistent database where the data is stored on the disk. I just did not want to deal with a separate database server process.

For the disk storage I had to pick one of the database systems that provide the file stores. (As I understand there are several options. I went with RocksDB.

Crate a crate

cargo new embedded-rocksdb
cd embedded-rocksdb

Dependencies

These are the dependencies in the Cargo.toml file.

examples/surrealdb/embedded-rocksdb/Cargo.toml

[package]
name = "embedded-rocksdb"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
serde = { version = "1.0", features = ["derive"] }
surrealdb = { version = "1.1", features = ["kv-rocksdb"] }
tokio = { version = "1.35", features = ["macros", "rt-multi-thread"] }

The code

examples/surrealdb/embedded-rocksdb/src/main.rs

use surrealdb::Surreal;
use surrealdb::engine::local::RocksDb;

#[tokio::main]
async fn main() -> surrealdb::Result<()> {
    let _db = Surreal::new::<RocksDb>("tempdb").await?;

    // let current_dir = std::env::current_dir().unwrap();
    // let _db = Surreal::new::<RocksDb>(current_dir.join("tempdb")).await?;

    Ok(())
}

Running the code

cargo run

Running this code will first need to compile it that might take several minutes. Then it will create a folder called tempdb thats store the database.

This folder will be created in the root of the crate.

In some earlier versions of SurrealDB this feature was broken and I had to use a full-path to the folder. I left that code in as comment to show you that you can also provide a full path to the database folder.

Conclusion

I know we have not done much yet, but I like to celebrate even small steps.

If you need an in-memory database with slight modifications this can be converted to one. See Setting up an in-memory SurrealDB database in Rust.