Trait WriteBufferManager 

pub trait WriteBufferManager:
    Send
    + Sync
    + Debug {
    // Required methods
    fn should_flush_engine(&self) -> bool;
    fn should_stall(&self) -> bool;
    fn reserve_mem(&self, mem: usize);
    fn schedule_free_mem(&self, mem: usize);
    fn free_mem(&self, mem: usize);
    fn memory_usage(&self) -> usize;
    fn flush_limit(&self) -> usize;
}

Global write buffer (memtable) manager.

Tracks write buffer (memtable) usages and decide whether the engine needs to flush.

Required Methods

fn should_flush_engine(&self) -> bool

Returns whether to trigger the engine.

fn should_stall(&self) -> bool

Returns whether to stall write requests.

fn reserve_mem(&self, mem: usize)

Reserves mem bytes.

fn schedule_free_mem(&self, mem: usize)

Tells the manager we are freeing mem bytes.

We are in the process of freeing mem bytes, so it is not considered when checking the soft limit.

fn free_mem(&self, mem: usize)

We have freed mem bytes.

fn memory_usage(&self) -> usize

Returns the total memory used by memtables.

fn flush_limit(&self) -> usize

Returns the mutable memtable memory limit.

The write buffer manager should flush memtables when the mutable memory usage exceeds this limit.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl WriteBufferManager for WriteBufferManagerImpl