Struct kvdb_memorydb::InMemory

pub struct InMemory { /* private fields */ }

A key-value database fulfilling the KeyValueDB trait, living in memory. This is generally intended for tests and is not particularly optimized.

Trait Implementations

impl Default for InMemory

fn default() -> InMemory

Returns the “default value” for a type.

impl KeyValueDB for InMemory

fn get(&self, col: u32, key: &[u8]) -> Result<Option<DBValue>>

Get a value by key.

fn get_by_prefix(&self, col: u32, prefix: &[u8]) -> Option<Box<[u8]>>

Get the first value matching the given prefix.

fn write(&self, transaction: DBTransaction) -> Result<()>

Write a transaction of changes to the backing store.

fn iter<'a>(
    &'a self,
    col: u32
) -> Box<dyn Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a>

Iterate over the data for a given column.

fn iter_with_prefix<'a>(
    &'a self,
    col: u32,
    prefix: &'a [u8]
) -> Box<dyn Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a>

Iterate over the data for a given column, returning all key/value pairs where the key starts with the given prefix.

fn restore(&self, _new_db: &str) -> Result<()>

Attempt to replace this database with a new one located at the given path.

fn transaction(&self) -> DBTransaction

Helper to create a new transaction.

fn io_stats(&self, _kind: Kind) -> IoStats

Query statistics.

fn has_key(&self, col: u32, key: &[u8]) -> Result<bool, Error>

Check for the existence of a value by key.

fn has_prefix(&self, col: u32, prefix: &[u8]) -> bool

Check for the existence of a value by prefix.

impl MallocSizeOf for InMemory

fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself. If T::size_of is a constant, consider implementing constant_size as well.

fn constant_size() -> Option<usize>where
    Self: Sized,

Used to optimize MallocSizeOf implementation for collections like Vec and HashMap to avoid iterating over them unnecessarily. The Self: Sized bound is for object safety.