Trait hashdb::HashDB [−][src]
pub trait HashDB<H: Hasher, T>: Send + Sync + AsHashDB<H, T> { fn keys(&self) -> HashMap<H::Out, i32>; fn get(&self, key: &H::Out) -> Option<T>; fn contains(&self, key: &H::Out) -> bool; fn insert(&mut self, value: &[u8]) -> H::Out; fn emplace(&mut self, key: H::Out, value: T); fn remove(&mut self, key: &H::Out); }
Trait modelling datastore keyed by a hash defined by the Hasher
.
Required Methods
fn keys(&self) -> HashMap<H::Out, i32>
Get the keys in the database together with number of underlying references.
fn get(&self, key: &H::Out) -> Option<T>
Look up a given hash into the bytes that hash to it, returning None if the hash is not known.
fn contains(&self, key: &H::Out) -> bool
Check for the existance of a hash-key.
fn insert(&mut self, value: &[u8]) -> H::Out
Insert a datum item into the DB and return the datum's hash for a later lookup. Insertions
are counted and the equivalent number of remove()
s must be performed before the data
is considered dead.
fn emplace(&mut self, key: H::Out, value: T)
Like insert()
, except you provide the key and the data is all moved.
fn remove(&mut self, key: &H::Out)
Remove a datum previously inserted. Insertions can be "owed" such that the same number of insert()
s may
happen without the data being eventually being inserted into the DB. It can be "owed" more than once.