Struct trie_db::FatDBMut

pub struct FatDBMut<'db, L> where
    L: TrieLayout,  { /* fields omitted */ }

A mutable Trie implementation which hashes keys and uses a generic HashDB backing database. Additionaly it stores inserted hash-key mappings for later retrieval.

Use it as a Trie or TrieMut trait object.

Implementations

impl<'db, L> FatDBMut<'db, L> where
    L: TrieLayout, 

pub fn new(
    db: &'db mut dyn HashDB<L::Hash, DBValue>,
    root: &'db mut TrieHash<L>
) -> Self

Create a new trie with the backing database db and empty root Initialise to the state entailed by the genesis block. This guarantees the trie is built correctly.

pub fn from_existing(
    db: &'db mut dyn HashDB<L::Hash, DBValue>,
    root: &'db mut TrieHash<L>
) -> Result<Self, TrieHash<L>, CError<L>>

Create a new trie with the backing database db and root.

Returns an error if root does not exist.

pub fn db(&self) -> &dyn HashDB<L::Hash, DBValue>

Get the backing database.

pub fn db_mut(&mut self) -> &mut dyn HashDB<L::Hash, DBValue>

Get the backing database.

Trait Implementations

impl<'db, L> TrieMut<L> for FatDBMut<'db, L> where
    L: TrieLayout, 

fn root(&mut self) -> &TrieHash<L>

Return the root of the trie.

fn is_empty(&self) -> bool

Is the trie empty?

fn contains(&self, key: &[u8]) -> Result<bool, TrieHash<L>, CError<L>>

Does the trie contain a given key?

fn get<'a, 'key>(
    &'a self,
    key: &'key [u8]
) -> Result<Option<DBValue>, TrieHash<L>, CError<L>> where
    'a: 'key, 

What is the value of the given key in this trie?

fn insert(
    &mut self,
    key: &[u8],
    value: &[u8]
) -> Result<Option<DBValue>, TrieHash<L>, CError<L>>

Insert a key/value pair into the trie. An empty value is equivalent to removing key from the trie. Returns the old value associated with this key, if it existed.

fn remove(
    &mut self,
    key: &[u8]
) -> Result<Option<DBValue>, TrieHash<L>, CError<L>>

Remove a key from the trie. Equivalent to making it equal to the empty value. Returns the old value associated with this key, if it existed.