Struct trie_db::FatDBMut

pub struct FatDBMut<'db, H, C> where
    H: Hasher + 'db,
    C: NodeCodec<H>,  { /* 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.

Methods

impl<'db, H, C> FatDBMut<'db, H, C> where     H: Hasher,     C: NodeCodec<H>,

pub fn new(db: &'db mut dyn HashDB<H, DBValue>, root: &'db mut H::Out) -> 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<H, DBValue>,     root: &'db mut H::Out ) -> Result<Self, H::Out, C::Error>

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<H, DBValue>

Get the backing database.

pub fn db_mut(&mut self) -> &mut dyn HashDB<H, DBValue>

Get the backing database.

Trait Implementations

impl<'db, H, C> TrieMut<H, C> for FatDBMut<'db, H, C> where     H: Hasher,     C: NodeCodec<H>,

fn root(&mut self) -> &H::Out

Return the root of the trie.

fn is_empty(&self) -> bool

Is the trie empty?

fn contains(&self, key: &[u8]) -> Result<bool, H::Out, C::Error>

Does the trie contain a given key?

fn get<'a, 'key>(     &'a self,     key: &'key [u8] ) -> Result<Option<DBValue>, H::Out, C::Error> 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>, H::Out, C::Error>

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>, H::Out, C::Error>

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.