Struct Engine 

pub struct Engine {
    pub(crate) db: DBWithThreadMode<MultiThreaded>,
    pub(crate) pool: Arc<Pool>,
    pub(crate) ctx: Arc<Context>,
    pub(crate) read_only: bool,
    pub(crate) secondary: bool,
    pub(crate) checksums: bool,
    corks: AtomicU32,
}

Handle to the opened RocksDB database and its shared resources.

One Engine exists per database, shared behind an Arc by every Map.

Fields

db: DBWithThreadMode<MultiThreaded>

The opened RocksDB instance.

pool: Arc<Pool>

Thread pool offloading uncached, blocking database requests from the tokio workers.

ctx: Arc<Context>

Resources constructed before the database is opened and outliving it (block caches, environment, column descriptors).

read_only: bool

Database was opened read-only; writes are rejected.

secondary: bool

Database was opened as a secondary follower of a primary instance.

checksums: bool

Verify block checksums on read.

corks: AtomicU32

Live cork count; nonzero suppresses the per-write WAL flush.

Implementations

impl Engine

pub fn backup(&self) -> Result

impl Engine

pub fn backup_list(&self) -> Result<impl Iterator<Item = String> + Send>

impl Engine

pub fn backup_count(&self) -> Result<usize>

impl Engine

fn backup_engine(&self) -> Result<BackupEngine>

impl Engine

fn backup_path(&self) -> Result<OsString>

impl Engine

pub fn file_list(&self) -> impl Iterator<Item = Result<SstFile>> + Send + use<>

impl Engine

pub fn memory_usage(&self) -> Result<String>

impl Engine

fn write_pool(&self, out: &mut String, name: &str, pool: &ColCache) -> Result

impl Engine

pub(crate) async fn open( ctx: Arc<Context>, desc: &[Descriptor], ) -> Result<Arc<Self>>

impl Engine

fn configure_cfds( ctx: &Arc<Context>, db_opts: &Options, desc: &[Descriptor], ) -> Result<(Vec<ColumnFamilyDescriptor>, Vec<String>)>

impl Engine

fn discover_cfs(path: &Path, opts: &Options) -> BTreeSet<String>

impl Engine

pub fn wait_compactions_blocking(&self) -> Result

Block until outstanding background compactions finish.

Waits without a timeout and does not flush first; aborts the wait if compaction has been paused.

pub fn sort(&self) -> Result

Flush the memtables to SST files.

Forces buffered writes out of memory into the on-disk LSM tree; distinct from flush and sync, which act on the write-ahead log.

pub fn update(&self) -> Result

Catch a secondary instance up to the primary’s latest writes.

Replays the primary’s newly appended WAL into this instance’s view; meaningful only when the database was opened as a secondary.

pub fn sync(&self) -> Result

Flush the write-ahead log and fsync it to disk.

Once this returns the buffered writes survive power loss. Heavier than flush, which stops at the OS page cache.

pub fn flush(&self) -> Result

Flush the buffered write-ahead log to the OS without an fsync.

Pushes WAL bytes to the page cache (durable against process crash, not power loss). This is the per-write flush that corking suppresses.

pub(crate) fn cork(&self)

Increment the cork count, suppressing the per-write WAL flush.

pub(crate) fn uncork(&self)

Decrement the cork count; the per-write flush resumes at zero.

pub fn corked(&self) -> bool

Whether any cork is currently held.

When true, Map insert and remove skip their post-write WAL flush so the records coalesce into one batch. Corking is purely a backend write-buffering signal: it never changes application logic or any observable database API behavior, because a write lands in the memtable synchronously and reads back regardless of WAL flush state. See the cork module.

pub(crate) fn property_integer( &self, cf: &impl AsColumnFamilyRef, name: &CStr, ) -> Result<u64>

Query for database property by null-terminated name which is expected to have a result with an integer representation. This is intended for low-overhead programmatic use.

pub(crate) fn property( &self, cf: &impl AsColumnFamilyRef, name: &str, ) -> Result<String>

Query for database property by name receiving the result in a string.

pub(crate) fn cf(&self, name: &str) -> Arc<BoundColumnFamily<'_>>

Look up a column-family handle by name.

Panics if the family was not described before the database was opened.

pub fn has_cf(&self, name: &str) -> bool

Whether a column family with this name exists.

pub fn current_sequence(&self) -> u64

The latest RocksDB sequence number, a monotonic counter of writes.

pub fn is_read_only(&self) -> bool

Whether writes are rejected: true for a read-only or secondary open.

pub fn is_secondary(&self) -> bool

Whether the database was opened as a secondary follower of a primary.

Trait Implementations

impl Drop for Engine

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.