[−][src]Trait hash_db::HashDB
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.
Trait Implementations
impl<'a, H: Hasher, T> AsHashDB<H, T> for &'a mut dyn HashDB<H, T>
[src]
impl<'a, H: Hasher, T> AsHashDB<H, T> for &'a mut dyn HashDB<H, T>
fn as_hash_db(&self) -> &dyn HashDB<H, T> | [src] |
fn as_hash_db_mut<'b>(&'b mut self) -> &'b mut (dyn HashDB<H, T> + 'b) | [src] |