Struct PostgresStore 

pub struct PostgresStore { /* private fields */ }

Postgres-based cache store for durable caching.

This store is used as the Durable tier in the tiered cache system. It provides persistent caching that survives restarts.

Runtime Invariants

• No DDL: This store never creates, alters, or drops tables
• Assumes table exists: All queries assume the table is present
• Errors propagate: SQL errors bubble up without retry

Schema

The store expects a table with the following schema:

CREATE TABLE {schema}.{table} (
    key TEXT PRIMARY KEY,
    value BYTEA,
    is_none BOOLEAN NOT NULL,
    expires_at TIMESTAMPTZ,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    CHECK (
        (is_none = TRUE AND value IS NULL)
     OR (is_none = FALSE AND value IS NOT NULL)
    )
);

CREATE INDEX idx_{table}_expires
ON {schema}.{table} (expires_at)
WHERE expires_at IS NOT NULL;

Use PostgresBuilder to create instances, or create the schema manually in your migrations.

Implementations

impl PostgresStore

pub async fn cleanup_expired(&self) -> Result<usize>

Clean up expired entries.

This is an optional maintenance operation that removes expired entries from the database. It’s not required for correctness (expired entries are filtered out on read), but can help with storage efficiency.

Returns the number of entries removed.

Trait Implementations

impl CacheStore for PostgresStore

fn get<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<Option<CacheEntry>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Get an entry from the store

fn set<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, entry: CacheEntry, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Set an entry in the store.

fn delete<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<bool>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Delete a specific key

fn invalidate<'life0, 'life1, 'async_trait>( &'life0 self, pattern: &'life1 CacheKeyPattern, ) -> Pin<Box<dyn Future<Output = Result<usize>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Delete keys matching a pattern

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

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

Clear all entries

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

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

Get statistics about the store

impl Debug for PostgresStore

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

Formats the value using the given formatter.