Struct Memtable 

pub struct Memtable { /* private fields */ }

In-memory write buffer

Stores mutations in memory with token-based ordering. Each partition can have multiple mutations (e.g., multiple rows with different clustering keys).

Implementations

impl Memtable

pub fn new() -> Self

Create a new memtable

pub fn insert(&mut self, _mutation: Mutation) -> Result<()>

Insert a mutation into the memtable

Mutations are grouped by partition key (DecoratedKey). Multiple mutations for the same partition are stored as a vector.

pub fn insert_with_key( &mut self, key: DecoratedKey, mutation: Mutation, ) -> Result<()>

Insert a mutation with an explicit decorated key

This is the primary insertion API. The caller is responsible for computing the decorated key from the partition key using the table schema.

pub fn get(&self, key: &DecoratedKey) -> Option<&[Mutation]>

Get all mutations for a given partition key

pub fn is_empty(&self) -> bool

Check if memtable is empty

pub fn size_bytes(&self) -> usize

Get current size in bytes (approximate)

pub fn row_count(&self) -> usize

Get approximate row count

pub fn should_flush(&self, threshold_bytes: usize) -> bool

Check if memtable should be flushed

pub fn created_at(&self) -> i64

Get creation timestamp (microseconds since Unix epoch)

pub fn iter(&self) -> impl Iterator<Item = (&DecoratedKey, &[Mutation])>

Iterate over all partitions and their mutations

Returns an iterator over (DecoratedKey, mutations) pairs in token order.

pub fn clear(&mut self)

Clear all data from the memtable

Used after successful flush to SSTable.

Trait Implementations

impl Debug for Memtable

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

Formats the value using the given formatter.

impl Default for Memtable

fn default() -> Self

Returns the “default value” for a type.