Redish

A lightweight in-memory key-value storage DB created based on LSM Tree.

Features

• Lightweight LSM tree based key-value storage
• Type-friendly
• TTL support for keys
• Persistence with sstable auto-merge
• Write-ahead log (WAL)
• Optimistic transaction management
• Bloom filter with optional caching
• Optional index caching
• Optional value caching
• Optional compression (lz4, zstd or snappy)

Default settings are:

• WAL on
• bloom filter on
• index caching on (100Mb cache, 100 entries/sstables)
• value caching on (200Mb cache, 200k values)
• compression off All these settings could be altered via TreeSettingsBuilder.

Usage:

use std::time::Duration;
use redish::tree::Tree;
use bincode::{Decode, Encode};

#[derive(Debug, Encode, Decode, Clone)]
struct User {
    user_id: u64,
    username: String,
}
let user = User {user_id: 3, username: "JohnDoe2020".to_string()};

// to use default path for db 
let mut tree = Tree::load()?;

// or specified path
let mut tree2 = Tree::load_with_path("/path/to/db/with_file_name")?;


tree.put(b"key1".to_string().into_bytes(), "value".to_string().into_bytes())?;
tree.put_with_ttl("key2".to_string().into_bytes(), "value".to_string().into_bytes(), Some(Duration::from_secs(60)))?;

// type-friendly usage with turbo-fish
tree.put_typed::<User>("key3", &user)?;

assert_eq!(user.username, tree.get_typed::<User>("key3"));

Creating TreeSettings for Tree:

let tree = Tree::load_with_settings(
            TreeSettingsBuilder::new()
                .db_path("./my_db")
                .mem_table_max_size(20000)
                .index_cache(true)
                .value_cache(true)
                .compressor(CompressionConfig::best())
                .build()
        )?;

Using transactions:

let tx_id1 = tree.begin_transaction()?;
let tx_id2 = tree.begin_transaction()?;
tree.put_tx(tx_id1, b"key1".to_vec(), b"JohnDoe".to_vec(), None)?;
tree.put_tx(tx_id2, b"key_to_rollback".to_vec(), b"NotJohnDoe".to_vec(), None)?;
tree.commit_transaction(tx_id1)?;
tree.rollback_transaction(tx_id2)?;