Struct MemDb

pub struct MemDb(/* private fields */);

This implements Database as an in-memory hash map. commit is not atomic.

Implementations

impl MemDb

pub fn new() -> Self

Create a new instance

pub fn count(&self, col: ColumnId) -> usize

Count number of values in a column

Trait Implementations

impl<H> Database<H> for MemDb

where H: Clone + AsRef<[u8]>,

fn commit(&self, transaction: Transaction<H>) -> Result<()>

Commit the transaction to the database atomically. Any further calls to get or lookup will reflect the new state.

fn get(&self, col: ColumnId, key: &[u8]) -> Option<Vec<u8>>

Retrieve the value previously stored against key or None if key is not currently in the database.

fn contains(&self, col: ColumnId, key: &[u8]) -> bool

Check if the value exists in the database without retrieving it.

fn value_size(&self, col: ColumnId, key: &[u8]) -> Option<usize>

Check value size in the database possibly without retrieving it.

fn with_get(&self, col: ColumnId, key: &[u8], f: &mut dyn FnMut(&[u8]))

Call f with the value previously stored against key.

fn supports_ref_counting(&self) -> bool

Check if database supports internal ref counting for state data.

fn sanitize_key(&self, _key: &mut Vec<u8>)

Remove a possible path-prefix from the key.

impl Default for MemDb

fn default() -> MemDb

Returns the “default value” for a type.