Struct ckb_db::db_with_ttl::DBWithTTL

pub struct DBWithTTL { /* fields omitted */ }

DB with ttl support wrapper

TTL is accepted in seconds If TTL is non positive or not provided, the behaviour is TTL = infinity (int32_t)Timestamp(creation) is suffixed to values in Put internally Expired TTL values are deleted in compaction only:(Timestamp+ttl<time_now) Get/Iterator may return expired entries(compaction not run on them yet) Different TTL may be used during different Opens Example: Open1 at t=0 with ttl=4 and insert k1,k2, close at t=2. Open2 at t=3 with ttl=5. Now k1,k2 should be deleted at t>=5 read_only=true opens in the usual read-only mode. Compactions will not be triggered(neither manual nor automatic), so no expired entries removed

Implementations

impl DBWithTTL

pub fn open_cf<P, I, N>(path: P, cf_names: I, ttl: i32) -> Result<Self> where
    P: AsRef<Path>,
    I: IntoIterator<Item = N>,
    N: Into<String>, 

Open a database with ttl support.

pub fn get_pinned(
    &self,
    col: &str,
    key: &[u8]
) -> Result<Option<DBPinnableSlice<'_>>>

Return the value associated with a key using RocksDB’s PinnableSlice from the given column so as to avoid unnecessary memory copy.

pub fn put<K, V>(&self, col: &str, key: K, value: V) -> Result<()> where
    K: AsRef<[u8]>,
    V: AsRef<[u8]>, 

Insert a value into the database under the given key.

pub fn create_cf_with_ttl(&mut self, col: &str, ttl: i32) -> Result<()>

Create a new column family for the database.

pub fn drop_cf(&mut self, col: &str) -> Result<()>

Delete column family.

pub fn estimate_num_keys_cf(&self, col: &str) -> Result<Option<u64>>

“rocksdb.estimate-num-keys” - returns estimated number of total keys in the active and unflushed immutable memtables and storage.

Trait Implementations

impl Debug for DBWithTTL

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

Formats the value using the given formatter.