# 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)?;
```