Struct c3p0_postgres::deadpool::postgres::StatementCache

pub struct StatementCache { /* private fields */ }

Representation of a cache of Statements.

StatementCache is bound to one Client, and Statements generated by that Client must not be used with other Clients.

It can be used like that:

let client = pool.get().await?;
let stmt = client
    .statement_cache
    .prepare(&client, "SELECT 1")
    .await;
let rows = client.query(stmt, &[]).await?;
...

Normally, you probably want to use the ClientWrapper::prepare_cached() and ClientWrapper::prepare_typed_cached() methods instead (or the similar ones on Transaction).

Implementations

impl StatementCache

pub fn size(&self) -> usize

Returns current size of this StatementCache.

pub fn clear(&self)

Clears this StatementCache.

Important: This only clears the StatementCache of one Client instance. If you want to clear the StatementCache of all Clients you should be calling pool.manager().statement_caches.clear() instead.

pub fn remove(&self, query: &str, types: &[Type]) -> Option<Statement>

Removes a Statement from this StatementCache.

Important: This only removes a Statement from one Client cache. If you want to remove a Statement from all StatementCaches you should be calling pool.manager().statement_caches.remove() instead.

pub async fn prepare( &self, client: &Client, query: &str ) -> Result<Statement, Error>

Creates a new prepared Statement using this StatementCache, if possible.

See tokio_postgres::Client::prepare().

pub async fn prepare_typed( &self, client: &Client, query: &str, types: &[Type] ) -> Result<Statement, Error>

Creates a new prepared Statement with specifying its Types explicitly using this StatementCache, if possible.

See tokio_postgres::Client::prepare_typed().

Trait Implementations

impl Debug for StatementCache

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

Formats the value using the given formatter.