Struct sp_state_machine::OffchainOverlayedChanges

pub struct OffchainOverlayedChanges(_);

In-memory storage for offchain workers recoding changes for the actual offchain storage implementation.

Implementations

impl OffchainOverlayedChanges

pub fn into_iter(
    self
) -> impl Iterator<Item = ((Vec<u8>, Vec<u8>), OffchainOverlayedChange)>

Consume the offchain storage and iterate over all key value pairs.

Examples found in repository

src/overlayed_changes/offchain.rs (line 51)

	pub fn drain(&mut self) -> impl Iterator<Item = OffchainOverlayedChangesItemOwned> {
		sp_std::mem::take(self).into_iter()
	}

pub fn iter(
    &self
) -> impl Iterator<Item = (&'_ (Vec<u8>, Vec<u8>), &'_ OffchainOverlayedChange)>

Iterate over all key value pairs by reference.

pub fn drain(
    &mut self
) -> impl Iterator<Item = ((Vec<u8>, Vec<u8>), OffchainOverlayedChange)>

Drain all elements of changeset.

Examples found in repository

src/overlayed_changes/mod.rs (line 470)

	pub fn offchain_drain_committed(
		&mut self,
	) -> impl Iterator<Item = ((StorageKey, StorageKey), OffchainOverlayedChange)> {
		self.offchain.drain()
	}

pub fn remove(&mut self, prefix: &[u8], key: &[u8])

Remove a key and its associated value from the offchain database.

Examples found in repository

src/overlayed_changes/mod.rs (line 631)

	pub fn set_offchain_storage(&mut self, key: &[u8], value: Option<&[u8]>) {
		use sp_core::offchain::STORAGE_PREFIX;
		match value {
			Some(value) => self.offchain.set(STORAGE_PREFIX, key, value),
			None => self.offchain.remove(STORAGE_PREFIX, key),
		}
	}

pub fn set(&mut self, prefix: &[u8], key: &[u8], value: &[u8])

Set the value associated with a key under a prefix to the value provided.

Examples found in repository

src/overlayed_changes/mod.rs (line 630)

	pub fn set_offchain_storage(&mut self, key: &[u8], value: Option<&[u8]>) {
		use sp_core::offchain::STORAGE_PREFIX;
		match value {
			Some(value) => self.offchain.set(STORAGE_PREFIX, key, value),
			None => self.offchain.remove(STORAGE_PREFIX, key),
		}
	}

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

Obtain a associated value to the given key in storage with prefix.

pub fn overlay(
    &self
) -> &OverlayedMap<(Vec<u8>, Vec<u8>), OffchainOverlayedChange>

Reference to inner change set.

pub fn overlay_mut(
    &mut self
) -> &mut OverlayedMap<(Vec<u8>, Vec<u8>), OffchainOverlayedChange>

Mutable reference to inner change set.

Examples found in repository

src/overlayed_changes/mod.rs (line 359)

	pub fn start_transaction(&mut self) {
		self.top.start_transaction();
		for (_, (changeset, _)) in self.children.iter_mut() {
			changeset.start_transaction();
		}
		self.offchain.overlay_mut().start_transaction();
	}

	/// Rollback the last transaction started by `start_transaction`.
	///
	/// Any changes made during that transaction are discarded. Returns an error if
	/// there is no open transaction that can be rolled back.
	pub fn rollback_transaction(&mut self) -> Result<(), NoOpenTransaction> {
		self.top.rollback_transaction()?;
		retain_map(&mut self.children, |_, (changeset, _)| {
			changeset
				.rollback_transaction()
				.expect("Top and children changesets are started in lockstep; qed");
			!changeset.is_empty()
		});
		self.offchain
			.overlay_mut()
			.rollback_transaction()
			.expect("Top and offchain changesets are started in lockstep; qed");
		Ok(())
	}

	/// Commit the last transaction started by `start_transaction`.
	///
	/// Any changes made during that transaction are committed. Returns an error if there
	/// is no open transaction that can be committed.
	pub fn commit_transaction(&mut self) -> Result<(), NoOpenTransaction> {
		self.top.commit_transaction()?;
		for (_, (changeset, _)) in self.children.iter_mut() {
			changeset
				.commit_transaction()
				.expect("Top and children changesets are started in lockstep; qed");
		}
		self.offchain
			.overlay_mut()
			.commit_transaction()
			.expect("Top and offchain changesets are started in lockstep; qed");
		Ok(())
	}

	/// Call this before transfering control to the runtime.
	///
	/// This protects all existing transactions from being removed by the runtime.
	/// Calling this while already inside the runtime will return an error.
	pub fn enter_runtime(&mut self) -> Result<(), AlreadyInRuntime> {
		self.top.enter_runtime()?;
		for (_, (changeset, _)) in self.children.iter_mut() {
			changeset
				.enter_runtime()
				.expect("Top and children changesets are entering runtime in lockstep; qed")
		}
		self.offchain
			.overlay_mut()
			.enter_runtime()
			.expect("Top and offchain changesets are started in lockstep; qed");
		Ok(())
	}

	/// Call this when control returns from the runtime.
	///
	/// This commits all dangling transaction left open by the runtime.
	/// Calling this while outside the runtime will return an error.
	pub fn exit_runtime(&mut self) -> Result<(), NotInRuntime> {
		self.top.exit_runtime()?;
		for (_, (changeset, _)) in self.children.iter_mut() {
			changeset
				.exit_runtime()
				.expect("Top and children changesets are entering runtime in lockstep; qed");
		}
		self.offchain
			.overlay_mut()
			.exit_runtime()
			.expect("Top and offchain changesets are started in lockstep; qed");
		Ok(())
	}

Trait Implementations

impl Clone for OffchainOverlayedChanges

fn clone(&self) -> OffchainOverlayedChanges

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for OffchainOverlayedChanges

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

Formats the value using the given formatter.

impl Default for OffchainOverlayedChanges

fn default() -> OffchainOverlayedChanges

Returns the “default value” for a type.