Struct Memtable 

pub struct Memtable { /* private fields */ }

Memtable - an in-memory sorted write buffer

Provides O(log n) insert, lookup, and delete operations. When the memtable reaches a size threshold, it should be flushed to disk as an SSTable.

Implementations

impl Memtable

pub fn new() -> Memtable

Creates a new empty Memtable

pub fn with_sequence(sequence: u64) -> Memtable

Creates a new Memtable with a starting sequence number

pub fn put(&mut self, key: Vec<u8>, value: Vec<u8>)

Inserts or updates a key-value pair

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

Retrieves a value by key

Returns:

• Some(Some(value)) if the key exists with a value
• Some(None) if the key was deleted (tombstone)
• None if the key is not in the memtable

pub fn delete(&mut self, key: Vec<u8>)

Marks a key as deleted with a tombstone

pub fn size_bytes(&self) -> u64

Returns the approximate size of the memtable in bytes

pub fn len(&self) -> usize

Returns the number of entries in the memtable

pub fn is_empty(&self) -> bool

Returns true if the memtable is empty

pub fn sequence(&self) -> u64

Returns the current sequence number

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

Returns an iterator over all entries in sorted order

pub fn range<R>( &self, range: R, ) -> impl Iterator<Item = (&Vec<u8>, &MemtableEntry)>

where R: RangeBounds<Vec<u8>>,

Returns an iterator over a range of keys

pub fn clear(&mut self)

Clears the memtable

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

Consumes the memtable and returns all entries sorted by key

Trait Implementations

impl Debug for Memtable

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

Formats the value using the given formatter.

impl Default for Memtable

fn default() -> Memtable

Returns the “default value” for a type.