Copyright	(c) 2011 MailRank Inc.
License	Apache
Maintainer	Mark Hibberd <mark@hibberd.id.au>, Nathan Hunter <nhunter@janrain.com>
Stability	experimental
Portability	portable
Safe Haskell	None
Language	Haskell98

Network.Riak.Connection.Pool

Description

A high-performance striped pooling abstraction for managing connections to a Riak cluster. This is a thin wrapper around Pool.

Synopsis

data Pool
client :: Pool -> Client
create :: Client -> Int -> NominalDiffTime -> Int -> IO Pool
idleTime :: Pool -> NominalDiffTime
maxConnections :: Pool -> Int
numStripes :: Pool -> Int
withConnection :: Pool -> (Connection -> IO a) -> IO a
withConnectionM :: MonadBaseControl IO m => Pool -> (Connection -> m a) -> m a

Documentation

data Pool Source #

A pool of connections to a Riak server.

This pool is "striped", i.e. it consists of several sub-pools that are managed independently.

The total number of connections that can possibly be open at once is maxConnections * numStripes.

Instances

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

client :: Pool -> Client Source #

Client specification. The client ID is ignored, and always regenerated automatically for each new connection.

create Source #

Arguments

:: Client	Client configuration. The client ID is ignored, and always regenerated automatically for each new connection.
-> Int	Stripe count. The number of distinct sub-pools to maintain. The smallest acceptable value is 1.
-> NominalDiffTime	Amount of time for which an unused connection is kept open. The smallest acceptable value is 0.5 seconds. The elapsed time before closing may be a little longer than requested, as the reaper thread wakes at 2-second intervals.
-> Int	Maximum number of connections to keep open per stripe. The smallest acceptable value is 1. Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.
-> IO Pool

Create a new connection pool.

idleTime :: Pool -> NominalDiffTime Source #

Amount of time for which an unused connection is kept open. The smallest acceptable value is 0.5 seconds.

The elapsed time before closing may be a little longer than requested, as the reaper thread wakes at 1-second intervals.

maxConnections :: Pool -> Int Source #

Maximum number of connections to keep open per stripe. The smallest acceptable value is 1.

Requests for connections will block if this limit is reached on a single stripe, even if other stripes have idle connections available.

numStripes :: Pool -> Int Source #

Stripe count. The number of distinct sub-pools to maintain. The smallest acceptable value is 1.

withConnection :: Pool -> (Connection -> IO a) -> IO a Source #

Temporarily take a connection from a Pool, perform an action with it, and return it to the pool afterwards.

If the pool has a connection available, it is used immediately.
Otherwise, if the maximum number of connections has not been reached, a new connection is created and used.
If the maximum number of connections has been reached, this function blocks until a connection becomes available, then that connection is used.

If the action throws an exception of any type, the Connection is destroyed, and not returned to the pool.

It probably goes without saying that you should never call disconnect on a connection, as doing so will cause a subsequent user (who expects the connection to be valid) to throw an exception.

withConnectionM :: MonadBaseControl IO m => Pool -> (Connection -> m a) -> m a Source #

Temporarily take a connection from a Pool, perform an action with it, and return it to the pool afterwards. This is a generalization of withConnection, which remains specialized to prevent breaking source compatibility with existing code.

If the pool has a connection available, it is used immediately.
Otherwise, if the maximum number of connections has not been reached, a new connection is created and used.
If the maximum number of connections has been reached, this function blocks until a connection becomes available, then that connection is used.

If the action throws an exception of any type, the Connection is destroyed, and not returned to the pool.

It probably goes without saying that you should never call disconnect on a connection, as doing so will cause a subsequent user (who expects the connection to be valid) to throw an exception.