Struct ValRef 

pub struct ValRef { /* private fields */ }

A reference to a value in the storage engine.

Implementations

impl ValRef

pub fn slice(&self) -> &[u8]

Returns the data as a byte slice.

Examples found in repository

examples/demo.rs (line 25)

fn main() -> Result<(), OpCode> {
    let path = std::env::temp_dir().join("mace");
    let _ = std::fs::remove_dir_all(&path);
    let opt = Options::new(path).validate()?;
    let db = Mace::new(opt)?;
    let bucket = db.new_bucket("test", BucketOptions::default())?;

    // start a read-write transaction
    let kv = bucket.begin()?;
    kv.put("foo", "bar")?;
    kv.put("fool", "+1s")?;
    kv.put("foolish", "elder")?;

    // can't create two identical keys
    let r = kv.put("foolish", "114514").err();
    assert_eq!(r.unwrap(), OpCode::AbortTx);

    // use `update` for exist key or use `upsert` when unsure
    let r = kv.update("foolish", "114514");
    assert!(r.is_ok());

    let r = kv.get("foo")?;
    assert_eq!(r.slice(), "bar".as_bytes());
    kv.del("foolish")?;
    kv.commit()?;

    // rollback
    let kv = bucket.begin()?;
    kv.put("mo", "ha")?;
    drop(kv);

    // start a read-only transaction
    let view = bucket.view()?;
    let r = view.get("foo")?;
    assert_eq!(r.slice(), "bar".as_bytes());
    let r = view.get("mo");
    assert_eq!(r.err().unwrap(), OpCode::NotFound);

    // prefix scan
    let r = view.get("foolish");
    assert!(r.is_err() && r.err().unwrap() == OpCode::NotFound);
    let iter = view.seek("foo");
    assert_eq!(iter.count(), 2);

    Ok(())
}

pub fn to_vec(self) -> Vec<u8>

Converts the reference into a owned Vec.

Trait Implementations

impl Clone for ValRef

fn clone(&self) -> ValRef

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.