pub trait HashDB<H, T>: Send + Sync + AsHashDB<H, T> where
H: Hasher, {
fn get(
&self,
key: &<H as Hasher>::Out,
prefix: (&[u8], Option<u8>)
) -> Option<T>;
fn contains(
&self,
key: &<H as Hasher>::Out,
prefix: (&[u8], Option<u8>)
) -> bool;
fn insert(
&mut self,
prefix: (&[u8], Option<u8>),
value: &[u8]
) -> <H as Hasher>::Out;
fn emplace(
&mut self,
key: <H as Hasher>::Out,
prefix: (&[u8], Option<u8>),
value: T
);
fn remove(&mut self, key: &<H as Hasher>::Out, prefix: (&[u8], Option<u8>));
}
Expand description
Trait modelling datastore keyed by a hash defined by the Hasher
.
Required methods
Look up a given hash into the bytes that hash to it, returning None if the hash is not known.
Check for the existance of a hash-key.
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.
Like insert()
, except you provide the key and the data is all moved.
Trait Implementations
sourceimpl<'a, H, T> AsHashDB<H, T> for &'a mut (dyn HashDB<H, T> + 'a) where
H: Hasher,
impl<'a, H, T> AsHashDB<H, T> for &'a mut (dyn HashDB<H, T> + 'a) where
H: Hasher,
sourcepub fn as_hash_db(&self) -> &dyn HashDB<H, T>
pub fn as_hash_db(&self) -> &dyn HashDB<H, T>
Perform upcast to HashDB for anything that derives from HashDB.
sourcepub fn as_hash_db_mut(&'b mut self) -> &'b mut (dyn HashDB<H, T> + 'b)
pub fn as_hash_db_mut(&'b mut self) -> &'b mut (dyn HashDB<H, T> + 'b)
Perform mutable upcast to HashDB for anything that derives from HashDB.