Struct MitoRegion

pub(crate) struct MitoRegion {
    pub(crate) region_id: RegionId,
    pub(crate) version_control: Arc<VersionControl>,
    pub(crate) access_layer: AccessLayerRef,
    pub(crate) manifest_ctx: Arc<ManifestContext>,
    pub(crate) file_purger: FilePurgerRef,
    pub(crate) provider: Provider,
    last_flush_millis: AtomicI64,
    last_compaction_millis: AtomicI64,
    time_provider: Arc<dyn TimeProvider>,
    pub(crate) topic_latest_entry_id: AtomicU64,
    pub(crate) memtable_builder: MemtableBuilderRef,
    stats: ManifestStats,
}

Metadata and runtime status of a region.

Writing and reading a region follow a single-writer-multi-reader rule:

• Only the region worker thread this region belongs to can modify the metadata.
• Multiple reader threads are allowed to read a specific version of a region.

Fields

region_id: RegionId

Id of this region.

Accessing region id from the version control is inconvenient so we also store it here.

version_control: Arc<VersionControl>

Version controller for this region.

We MUST update the version control inside the write lock of the region manifest manager.

access_layer: AccessLayerRef

SSTs accessor for this region.

manifest_ctx: Arc<ManifestContext>

Context to maintain manifest for this region.

file_purger: FilePurgerRef

SST file purger.

provider: Provider

The provider of log store.

last_flush_millis: AtomicI64

Last flush time in millis.

last_compaction_millis: AtomicI64

Last compaction time in millis.

time_provider: Arc<dyn TimeProvider>

Provider to get current time.

topic_latest_entry_id: AtomicU64

The topic’s latest entry id since the region’s last flushing. Only used for remote WAL pruning.

The value will be updated to the high watermark of the topic if region receives a flush request or schedules a periodic flush task and the region’s memtable is empty.

There are no WAL entries in range [flushed_entry_id, topic_latest_entry_id] for current region, which means these WAL entries maybe able to be pruned up to topic_latest_entry_id.

memtable_builder: MemtableBuilderRef

Memtable builder for the region.

stats: ManifestStats

manifest stats

Implementations

impl MitoRegion

pub(crate) async fn stop(&self)

Stop background managers for this region.

pub(crate) fn metadata(&self) -> RegionMetadataRef

Returns current metadata of the region.

pub(crate) fn primary_key_encoding(&self) -> PrimaryKeyEncoding

Returns primary key encoding of the region.

pub(crate) fn version(&self) -> Arc<Version>

Returns current version of the region.

pub(crate) fn last_flush_millis(&self) -> i64

Returns last flush timestamp in millis.

pub(crate) fn update_flush_millis(&self)

Update flush time to current time.

pub(crate) fn last_compaction_millis(&self) -> i64

Return last compaction time in millis.

pub(crate) fn update_compaction_millis(&self)

Update compaction time to now millis.

pub(crate) fn region_dir(&self) -> &str

Returns the region dir.

pub(crate) fn is_writable(&self) -> bool

Returns whether the region is writable.

pub(crate) fn is_flushable(&self) -> bool

Returns whether the region is flushable.

pub(crate) fn is_downgrading(&self) -> bool

Returns whether the region is downgrading.

pub(crate) fn is_follower(&self) -> bool

Returns whether the region is readonly.

pub(crate) fn state(&self) -> RegionRoleState

Returns the state of the region.

pub(crate) fn set_role(&self, next_role: RegionRole)

Sets the region role state.

pub(crate) fn set_altering(&self) -> Result<()>

Sets the altering state. You should call this method in the worker loop.

pub(crate) fn set_dropping(&self) -> Result<()>

Sets the dropping state. You should call this method in the worker loop.

pub(crate) fn set_truncating(&self) -> Result<()>

Sets the truncating state. You should call this method in the worker loop.

pub(crate) fn set_editing(&self) -> Result<()>

Sets the editing state. You should call this method in the worker loop.

pub(crate) async fn set_role_state_gracefully( &self, state: SettableRegionRoleState, )

Sets the region to readonly gracefully. This acquires the manifest write lock.

pub(crate) fn switch_state_to_writable(&self, expect: RegionLeaderState)

Switches the region state to RegionRoleState::Leader(RegionLeaderState::Writable) if the current state is expect. Otherwise, logs an error.

pub(crate) fn region_statistic(&self) -> RegionStatistic

Returns the region statistic.

fn estimated_wal_usage(&self, memtable_usage: u64) -> u64

Estimated WAL size in bytes. Use the memtables size to estimate the size of wal.

fn compare_exchange_state( &self, expect: RegionLeaderState, state: RegionRoleState, ) -> Result<()>

Sets the state of the region to given state if the current state equals to the expected.

Trait Implementations

impl Debug for MitoRegion

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

Formats the value using the given formatter.