Struct PostgresTimestampOracle

pub struct PostgresTimestampOracle<N>
where
    N: GenericNowFn<Timestamp>,
{
    timeline: String,
    next: N,
    postgres_client: Arc<PostgresClient>,
    metrics: Arc<Metrics>,
    read_only: bool,
}

A TimestampOracle backed by “Postgres”.

Fields

timeline: String

next: N

postgres_client: Arc<PostgresClient>

metrics: Arc<Metrics>

read_only: bool

A read-only timestamp oracle is NOT allowed to do operations that change the backing Postgres/CRDB state.

Implementations

impl<N> PostgresTimestampOracle<N>

where N: GenericNowFn<Timestamp> + Debug + 'static,

pub async fn open( config: PostgresTimestampOracleConfig, timeline: String, initially: Timestamp, next: N, read_only: bool, ) -> Self

Open a Postgres TimestampOracle instance with config, for the timeline named timeline. next generates new timestamps when invoked. Timestamps that are returned are made durable and will never retract.

async fn get_connection(&self) -> Result<Object, PoolError>

pub async fn get_all_timelines( config: PostgresTimestampOracleConfig, ) -> Result<Vec<(String, Timestamp)>, Error>

Returns a Vec of all known timelines along with their current greatest timestamp (max of read_ts and write_ts).

For use when initializing another TimestampOracle implementation from another oracle’s state.

NOTE: This method can have linearizability violations, but it’s hard to get around those. They will only occur during bootstrap, and only if/when we migrate between different oracle implementations. Once we migrated from the catalog-backed oracle to the postgres/crdb-backed oracle we can remove this code and it’s callsite.

async fn fallible_write_ts(&self) -> Result<WriteTimestamp<Timestamp>, Error>

async fn fallible_peek_write_ts(&self) -> Result<Timestamp, Error>

async fn fallible_read_ts(&self) -> Result<Timestamp, Error>

async fn fallible_apply_write(&self, write_ts: Timestamp) -> Result<(), Error>

fn ts_to_decimal(ts: Timestamp) -> Numeric

fn decimal_to_ts(ts: Numeric) -> Timestamp

Trait Implementations

impl<N> Debug for PostgresTimestampOracle<N>

where N: GenericNowFn<Timestamp> + Debug,

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

Formats the value using the given formatter.

impl<N> TimestampOracle<Timestamp> for PostgresTimestampOracle<N>

where N: GenericNowFn<Timestamp> + Debug + 'static,

fn write_ts<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = WriteTimestamp<Timestamp>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Acquire a new timestamp for writing.

fn peek_write_ts<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Timestamp> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Peek the current write timestamp.

fn read_ts<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Timestamp> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Acquire a new timestamp for reading.

fn apply_write<'life0, 'async_trait>( &'life0 self, write_ts: Timestamp, ) -> Pin<Box<dyn Future<Output = ()> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Mark a write at write_ts completed.