Safe Haskell	None
Language	Haskell2010

Hasql.Pool

Synopsis

data Pool
type Settings = (Int, Int, Settings)
acquire :: Settings -> IO Pool
release :: Pool -> IO ()
data UsageError
use :: Pool -> Session a -> IO (Either UsageError a)

Documentation

data Pool Source #

A pool of connections to DB.

type Settings = (Int, Int, Settings) Source #

Settings of the connection pool. Consist of:

Pool-size.
Timeout. An amount of time in milliseconds for which the unused connections are kept open.
Connection settings.

acquire :: Settings -> IO Pool Source #

Given the pool-size, timeout and connection settings create a connection-pool.

release :: Pool -> IO () Source #

Release the connection-pool.

data UsageError Source #

A union over the connection establishment error and the session error.

Constructors

ConnectionUsageError ConnectionError	Error during an attempt to connect.
SessionUsageError QueryError	Error during session execution.
PoolIsReleasedUsageError	Pool has been released and can no longer be used.

Instances

Instances details

Eq UsageError Source #
Instance details Defined in Hasql.Pool Methods (==) :: UsageError -> UsageError -> Bool # (/=) :: UsageError -> UsageError -> Bool #
Show UsageError Source #
Instance details Defined in Hasql.Pool Methods showsPrec :: Int -> UsageError -> ShowS # show :: UsageError -> String # showList :: [UsageError] -> ShowS #

use :: Pool -> Session a -> IO (Either UsageError a) Source #

Use a connection from the pool to run a session and return the connection to the pool, when finished. If the session fails with ClientError the connection gets reestablished.