kv-rs is a key-value pairs to an append-only log file,
and keeps a mapping of keys to file positions in memory.
All live keys must fit in memory.
Deletes write a tombstone value to the log file.
To remove old garbage, logs can be compacted by writing new logs containing only live
data, skipping replaced values and tombstones.
use std::path::PathBuf;
use kv_rs::error::Error;
use kv_rs::storage::engine::Engine;
use kv_rs::storage::log_cask::LogCask;
fn main() {
println!("Hello, kv CLI!");
run().unwrap();
println!("Bye~");
}
fn run() -> Result<(), Error> {
let storage_path = PathBuf::new().join("D:/workspace/kv/storage/kvdb");
// let storage_path = tempdir::TempDir::new("demo")?.path().join("kvdb");
let mut engine = LogCask::new(storage_path)?;
engine.set(b"b", vec![0x01])?;
engine.set(b"b", vec![0x02])?;
engine.set(b"e", vec![0x05])?;
engine.delete(b"e")?;
engine.set(b"c", vec![0x00])?;
engine.delete(b"c")?;
engine.set(b"c", vec![0x03])?;
engine.set(b"", vec![])?;
engine.set(b"a", vec![0x01])?;
engine.delete(b"f")?;
engine.delete(b"d")?;
engine.set(b"d", vec![0x04])?;
// Make sure the scan yields the expected results.
assert_eq!(
vec![
(b"".to_vec(), vec![]),
(b"a".to_vec(), vec![0x01]),
(b"b".to_vec(), vec![0x02]),
(b"c".to_vec(), vec![0x03]),
(b"d".to_vec(), vec![0x04]),
],
engine.scan(..).collect::<Result<Vec<_>,Error>> ()?,
);
let rs = engine.flush();
Ok(())
}