Trait hashdb::HashDB
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pub trait HashDB: AsHashDB + Send + Sync { fn keys(&self) -> HashMap<H256, i32>; fn get(&self, key: &H256) -> Option<DBValue>; fn contains(&self, key: &H256) -> bool; fn insert(&mut self, value: &[u8]) -> H256; fn emplace(&mut self, key: H256, value: DBValue); fn remove(&mut self, key: &H256); }
Trait modelling datastore keyed by a 32-byte Keccak hash.
Required Methods
fn keys(&self) -> HashMap<H256, i32>
Get the keys in the database together with number of underlying references.
fn get(&self, key: &H256) -> Option<DBValue>
Look up a given hash into the bytes that hash to it, returning None if the hash is not known.
fn contains(&self, key: &H256) -> bool
Check for the existance of a hash-key.
fn insert(&mut self, value: &[u8]) -> H256
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: H256, value: DBValue)
Like insert()
, except you provide the key and the data is all moved.
fn remove(&mut self, key: &H256)
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> AsHashDB for &'a mut HashDB
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fn as_hashdb(&self) -> &HashDB
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Perform upcast to HashDB for anything that derives from HashDB.
fn as_hashdb_mut(&mut self) -> &mut HashDB
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Perform mutable upcast to HashDB for anything that derives from HashDB.