nikidb

An embedded B+ tree-based persistent kv storage written in rust, similar to boltdb

example ```rust use nikidb::db::DB; use nikidb::db::DEFAULT_OPTIONS; use nikidb::error::{NKError, NKResult}; use nikidb::tx::Tx; use std::str;

fn main() { let db = DB::open("./test.db", DEFAULT_OPTIONS).unwrap();

//create bucket
db.update(Box::new(|tx: &mut Tx| -> NKResult<()> {
    match tx.create_bucket("default".as_bytes()) {
        Ok(_) => println!("create default bucket success"),
        Err(NKError::ErrBucketExists(e)) => println!("{} bucket exist", e),
        Err(e) => panic!("create bucket error"),
    }
    Ok(())
}))
.unwrap();

//set key value
db.update(Box::new(|tx: &mut Tx| -> NKResult<()> {
    let b = tx.bucket("default".as_bytes())?;
    b.put(b"abc", b"123").unwrap();
    Ok(())
}))
.unwrap();

//get key value
db.view(Box::new(|tx: &mut Tx| -> NKResult<()> {
    let b = tx.bucket("default".as_bytes())?;
    let v = b.get(b"abc").unwrap();
    println!("value:{:?}", str::from_utf8(v).unwrap());
    Ok(())
}))
.unwrap();

} ```