Struct sp_database::Transaction

pub struct Transaction<H>(pub Vec<Change<H>>);

A series of changes to the database that can be committed atomically. They do not take effect until passed into Database::commit.

Implementations

impl<H> Transaction<H>

pub fn new() -> Self

Create a new transaction to be prepared and committed atomically.

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

Set the value of key in col to value, replacing anything that is there currently.

pub fn set_from_vec(&mut self, col: ColumnId, key: &[u8], value: Vec<u8>)

Set the value of key in col to value, replacing anything that is there currently.

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

Remove the value of key in col.

pub fn store(&mut self, hash: H, preimage: &[u8])

Store the preimage of hash into the database, so that it may be looked up later with Database::lookup. This may be called multiple times, but Database::lookup but subsequent calls will ignore preimage and simply increase the number of references on hash.

pub fn release(&mut self, hash: H)

Release the preimage of hash from the database. An equal number of these to the number of corresponding stores must have been given before it is legal for Database::lookup to be unable to provide the preimage.

Trait Implementations

impl<H: Clone> Clone for Transaction<H>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<H: Default> Default for Transaction<H>

fn default() -> Transaction<H>

Returns the “default value” for a type.