Struct sp_state_machine::OverlayedChanges

pub struct OverlayedChanges { /* fields omitted */ }

The overlayed changes to state to be queried on top of the backend.

A transaction shares all prospective changes within an inner overlay that can be cleared.

Implementations

impl OverlayedChanges

pub fn is_empty(&self) -> bool

Whether the overlayed changes are empty.

pub fn set_collect_extrinsics(&mut self, collect_extrinsics: bool)

Ask to collect/not to collect extrinsics indices where key(s) has been changed.

pub fn storage(&self, key: &[u8]) -> Option<Option<&[u8]>>

Returns a double-Option: None if the key is unknown (i.e. and the query should be referred to the backend); Some(None) if the key has been deleted. Some(Some(...)) for a key whose value has been set.

#[must_use = "A change was registered, so this value MUST be modified."]pub fn value_mut_or_insert_with(
    &mut self,
    key: &[u8],
    init: impl Fn() -> StorageValue
) -> &mut StorageValue

Returns mutable reference to current changed value (prospective). If there is no value in the overlay, the default callback is used to initiate the value. Warning this function register a change, so the mutable reference MUST be modified.

pub fn child_storage(
    &self,
    child_info: &ChildInfo,
    key: &[u8]
) -> Option<Option<&[u8]>>

Returns a double-Option: None if the key is unknown (i.e. and the query should be referred to the backend); Some(None) if the key has been deleted. Some(Some(...)) for a key whose value has been set.

pub fn discard_prospective(&mut self)

Discard prospective changes to state.

pub fn commit_prospective(&mut self)

Commit prospective changes to state.

pub fn child_infos(&self) -> impl IntoIterator<Item = &ChildInfo>

Get an iterator over all pending and committed child tries in the overlay.

pub fn changes(
    &self,
    child_info: Option<&ChildInfo>
) -> impl Iterator<Item = (&StorageKey, &OverlayedValue)>

Get an iterator over all pending and committed changes.

Supplying None for child_info will only return changes that are in the top trie. Specifying some child_info will return only the changes in that child trie.

pub fn clone_pending(&self) -> OverlayedChangeSet

Return a clone of the currently pending changes.

pub fn replace_pending(&mut self, pending: OverlayedChangeSet)

Replace the currently pending changes.

pub fn into_storage_changes<B: Backend<H>, H: Hasher, N: BlockNumber>(
    self,
    backend: &B,
    changes_trie_state: Option<&ChangesTrieState<H, N>>,
    parent_hash: H::Out,
    cache: StorageTransactionCache<B::Transaction, H, N>
) -> Result<StorageChanges<B::Transaction, H, N>, String> where
    H::Out: Ord + Encode + 'static, 

Convert this instance with all changes into a StorageChanges instance.

pub fn drain_storage_changes<B: Backend<H>, H: Hasher, N: BlockNumber>(
    &mut self,
    backend: &B,
    changes_trie_state: Option<&ChangesTrieState<H, N>>,
    parent_hash: H::Out,
    cache: &mut StorageTransactionCache<B::Transaction, H, N>
) -> Result<StorageChanges<B::Transaction, H, N>, String> where
    H::Out: Ord + Encode + 'static, 

Drain all changes into a StorageChanges instance. Leave empty overlay in place.

pub fn storage_root<H: Hasher, N: BlockNumber, B: Backend<H>>(
    &self,
    backend: &B,
    cache: &mut StorageTransactionCache<B::Transaction, H, N>
) -> H::Out where
    H::Out: Ord + Encode, 

Generate the storage root using backend and all changes from prospective and committed.

Returns the storage root and caches storage transaction in the given cache.

pub fn changes_trie_root<'a, H: Hasher, N: BlockNumber, B: Backend<H>>(
    &self,
    backend: &B,
    changes_trie_state: Option<&'a ChangesTrieState<'a, H, N>>,
    parent_hash: H::Out,
    panic_on_storage_error: bool,
    cache: &mut StorageTransactionCache<B::Transaction, H, N>
) -> Result<Option<H::Out>, ()> where
    H::Out: Ord + Encode + 'static, 

Generate the changes trie root.

Returns the changes trie root and caches the storage transaction into the given cache.

Panics

Panics on storage error, when panic_on_storage_error is set.

pub fn default_child_info(&self, storage_key: &[u8]) -> Option<&ChildInfo>

Get child info for a storage key. Take the latest value so prospective first.

pub fn next_storage_key_change(
    &self,
    key: &[u8]
) -> Option<(&[u8], &OverlayedValue)>

Returns the next (in lexicographic order) storage key in the overlayed alongside its value. If no value is next then None is returned.

pub fn next_child_storage_key_change(
    &self,
    storage_key: &[u8],
    key: &[u8]
) -> Option<(&[u8], &OverlayedValue)>

Returns the next (in lexicographic order) child storage key in the overlayed alongside its value. If no value is next then None is returned.

Trait Implementations

impl Clone for OverlayedChanges

fn clone(&self) -> OverlayedChanges

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for OverlayedChanges

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

Formats the value using the given formatter.

impl Default for OverlayedChanges

fn default() -> OverlayedChanges

Returns the "default value" for a type.