Struct mysql::Pool

pub struct Pool { /* fields omitted */ }

Pool serves to provide you with a PooledConn's. However you can prepare statements directly on Pool without invoking Pool::get_conn.

Pool will hold at least min connections and will create as many as max connections with possible overhead of one connection per alive thread.

Example of multithreaded Pool usage:

let opts = get_opts();
let pool = Pool::new(opts).unwrap();
let mut threads = Vec::new();

for _ in 0..100 {
    let pool = pool.clone();
    threads.push(std::thread::spawn(move || {
        let mut conn = pool.get_conn().unwrap();
        let result: u8 = conn.query_first("SELECT 1").unwrap().unwrap();
        assert_eq!(result, 1_u8);
    }));
}

for t in threads.into_iter() {
    assert!(t.join().is_ok());
}

For more info on how to work with mysql connection please look at PooledConn documentation.

Methods

impl Pool

pub fn new<T: Into<Opts>>(opts: T) -> Result<Pool>

Creates new pool with min = 10 and max = 100.

pub fn new_manual<T: Into<Opts>>(
    min: usize,
    max: usize,
    opts: T
) -> Result<Pool>

Same as new but you can set min and max.

pub fn use_cache(&mut self, use_cache: bool)

A way to turn off searching for cached statement (on by default).

If turned on, then calls to Pool::{prepare, prep_exec, first_exec} will search for cached statement through all connections in the pool. Useless if the value of the stmt_cache_size option is 0.

pub fn check_health(&mut self, check_health: bool)

A way to turn off connection health check on each call to get_conn and prepare (prep_exec is not affected) (on by default).

pub fn get_conn(&self) -> Result<PooledConn>

Gives you a PooledConn.

Pool will check that connection is alive via Conn::ping and will call Conn::reset if necessary.

pub fn try_get_conn(&self, timeout_ms: u32) -> Result<PooledConn>

Will try to get connection for a duration of timeout_ms milliseconds.

Failure

This function will return Error::DriverError(DriverError::Timeout) if timeout was reached while waiting for new connection to become available.

pub fn start_transaction(&self, tx_opts: TxOpts) -> Result<Transaction<'static>>

Shortcut for pool.get_conn()?.start_transaction(..).

Trait Implementations

impl Clone for Pool

fn clone(&self) -> Pool

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Pool

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

Formats the value using the given formatter.