Struct sp_trie::NodeCodec

pub struct NodeCodec<H>(/* private fields */);

The Substrate format implementation of NodeCodec. Concrete implementation of a NodeCodecT with SCALE encoding.

It is generic over H the Hasher.

Trait Implementations

impl<H: Clone> Clone for NodeCodec<H>

fn clone(&self) -> NodeCodec<H>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<H: Default> Default for NodeCodec<H>

fn default() -> NodeCodec<H>

Returns the “default value” for a type.

impl<H> NodeCodec for NodeCodec<H>where H: Hasher,

const ESCAPE_HEADER: Option<u8> = _

Escape header byte sequence to indicate next node is a branch or leaf with hash of value, followed by the value node.

type Error = Error<<H as Hasher>::Out>

Codec error type.

type HashOut = <H as Hasher>::Out

Output type of encoded node hasher.

fn hashed_null_node() -> <H as Hasher>::Out

Get the hashed null node.

fn decode_plan(data: &[u8]) -> Result<NodePlan, Self::Error>

Decode bytes to a NodePlan. Returns Self::E on failure.

fn is_empty_node(data: &[u8]) -> bool

Check if the provided bytes correspond to the codecs “empty” node.

fn empty_node() -> &'static [u8]

Returns an encoded empty node.

fn leaf_node( partial: impl Iterator<Item = u8>, number_nibble: usize, value: Value<'_> ) -> Vec<u8>

Returns an encoded leaf node

fn extension_node( _partial: impl Iterator<Item = u8>, _nbnibble: usize, _child: ChildReference<<H as Hasher>::Out> ) -> Vec<u8>

Returns an encoded extension node

fn branch_node( _children: impl Iterator<Item = impl Borrow<Option<ChildReference<<H as Hasher>::Out>>>>, _maybe_value: Option<Value<'_>> ) -> Vec<u8>

Returns an encoded branch node. Takes an iterator yielding ChildReference<Self::HashOut> and an optional value.

fn branch_node_nibbled( partial: impl Iterator<Item = u8>, number_nibble: usize, children: impl Iterator<Item = impl Borrow<Option<ChildReference<<H as Hasher>::Out>>>>, value: Option<Value<'_>> ) -> Vec<u8>

Returns an encoded branch node with a possible partial path. number_nibble is the partial path length as in extension_node.

fn decode<'a>(data: &'a [u8]) -> Result<Node<'a>, Self::Error>

Decode bytes to a Node. Returns Self::E on failure.

impl<'a, H: Hasher> TrieCache<NodeCodec<H>> for TrieCache<'a, H>

fn get_or_insert_node( &mut self, hash: H::Out, fetch_node: &mut dyn FnMut() -> Result<NodeOwned<H::Out>, H::Out, Error<H::Out>> ) -> Result<&NodeOwned<H::Out>, H::Out, Error<H::Out>>

Get or insert a NodeOwned.

fn get_node(&mut self, hash: &H::Out) -> Option<&NodeOwned<H::Out>>

Get the NodeOwned that corresponds to the given hash.

fn lookup_value_for_key(&mut self, key: &[u8]) -> Option<&CachedValue<H::Out>>

Lookup value for the given key.

fn cache_value_for_key(&mut self, key: &[u8], data: CachedValue<H::Out>)

Cache the given value for the given key.