Struct sp_state_machine::TrieBackend

pub struct TrieBackend<S: TrieBackendStorage<H>, H: Hasher> { /* fields omitted */ }

Patricia trie-based backend. Transaction type is an overlay of changes to commit.

Methods

impl<S: TrieBackendStorage<H>, H: Hasher> TrieBackend<S, H> where
    H::Out: Codec, 

pub fn new(storage: S, root: H::Out) -> Self

Create new trie-based backend.

pub fn essence(&self) -> &TrieBackendEssence<S, H>

Get backend essence reference.

pub fn backend_storage(&self) -> &S

Get backend storage reference.

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

Get trie root.

pub fn into_storage(self) -> S

Consumes self and returns underlying storage.

Trait Implementations

impl<S: TrieBackendStorage<H>, H: Hasher> Backend<H> for TrieBackend<S, H> where
    H::Out: Ord + Codec, 

type Error = String

An error type when fetching data is not possible.

type Transaction = S::Overlay

Storage changes to be applied if committing

type TrieBackendStorage = S

Type of trie backend storage.

fn storage(&self, key: &[u8]) -> Result<Option<StorageValue>, Self::Error>

Get keyed storage or None if there is nothing associated.

fn child_storage(
    &self,
    storage_key: &[u8],
    child_info: ChildInfo,
    key: &[u8]
) -> Result<Option<StorageValue>, Self::Error>

Get keyed child storage or None if there is nothing associated.

fn next_storage_key(
    &self,
    key: &[u8]
) -> Result<Option<StorageKey>, Self::Error>

Return the next key in storage in lexicographic order or None if there is no value.

fn next_child_storage_key(
    &self,
    storage_key: &[u8],
    child_info: ChildInfo,
    key: &[u8]
) -> Result<Option<StorageKey>, Self::Error>

Return the next key in child storage in lexicographic order or None if there is no value.

fn for_keys_with_prefix<F: FnMut(&[u8])>(&self, prefix: &[u8], f: F)

Retrieve all entries keys which start with the given prefix and call f for each of those keys.

fn for_key_values_with_prefix<F: FnMut(&[u8], &[u8])>(
    &self,
    prefix: &[u8],
    f: F
)

Retrieve all entries keys and values of which start with the given prefix and call f for each of those keys.

fn for_keys_in_child_storage<F: FnMut(&[u8])>(
    &self,
    storage_key: &[u8],
    child_info: ChildInfo,
    f: F
)

Retrieve all entries keys of child storage and call f for each of those keys.

fn for_child_keys_with_prefix<F: FnMut(&[u8])>(
    &self,
    storage_key: &[u8],
    child_info: ChildInfo,
    prefix: &[u8],
    f: F
)

Retrieve all child entries keys which start with the given prefix and call f for each of those keys.

fn pairs(&self) -> Vec<(StorageKey, StorageValue)>

Get all key/value pairs into a Vec.

fn keys(&self, prefix: &[u8]) -> Vec<StorageKey>

Get all keys with given prefix

fn storage_root<I>(&self, delta: I) -> (H::Out, S::Overlay) where
    I: IntoIterator<Item = (StorageKey, Option<StorageValue>)>, 

Calculate the storage root, with given delta over what is already stored in the backend, and produce a "transaction" that can be used to commit. Does not include child storage updates.

fn child_storage_root<I>(
    &self,
    storage_key: &[u8],
    child_info: ChildInfo,
    delta: I
) -> (H::Out, bool, Self::Transaction) where
    I: IntoIterator<Item = (StorageKey, Option<StorageValue>)>,
    H::Out: Ord, 

Calculate the child storage root, with given delta over what is already stored in the backend, and produce a "transaction" that can be used to commit. The second argument is true if child storage root equals default storage root.

fn as_trie_backend(
    &mut self
) -> Option<&TrieBackend<Self::TrieBackendStorage, H>>

Try convert into trie backend.

fn register_overlay_stats(&mut self, _stats: &StateMachineStats)

Register stats from overlay of state machine.

fn usage_info(&self) -> UsageInfo

Query backend usage statistics (i/o, memory)

fn storage_hash(&self, key: &[u8]) -> Result<Option<H::Out>, Self::Error>

Get keyed storage value hash or None if there is nothing associated.

fn child_storage_hash(
    &self,
    storage_key: &[u8],
    child_info: ChildInfo,
    key: &[u8]
) -> Result<Option<H::Out>, Self::Error>

Get child keyed storage value hash or None if there is nothing associated.

fn exists_storage(&self, key: &[u8]) -> Result<bool, Self::Error>

true if a key exists in storage.

fn exists_child_storage(
    &self,
    storage_key: &[u8],
    child_info: ChildInfo,
    key: &[u8]
) -> Result<bool, Self::Error>

true if a key exists in child storage.

fn child_keys(
    &self,
    storage_key: &[u8],
    child_info: ChildInfo,
    prefix: &[u8]
) -> Vec<StorageKey>

Get all keys of child storage with given prefix

fn full_storage_root<I1, I2i, I2>(
    &self,
    delta: I1,
    child_deltas: I2
) -> (H::Out, Self::Transaction) where
    I1: IntoIterator<Item = (StorageKey, Option<StorageValue>)>,
    I2i: IntoIterator<Item = (StorageKey, Option<StorageValue>)>,
    I2: IntoIterator<Item = (StorageKey, I2i, OwnedChildInfo)>,
    H::Out: Ord + Encode, 

Calculate the storage root, with given delta over what is already stored in the backend, and produce a "transaction" that can be used to commit. Does include child storage updates.

fn wipe(&self) -> Result<(), Self::Error>

Wipe the state database.

fn commit(
    &self,
    _storage_root: H::Out,
    _transaction: Self::Transaction
) -> Result<(), Self::Error>

Commit given transaction to storage.

impl<S: TrieBackendStorage<H>, H: Hasher> Debug for TrieBackend<S, H>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.