Database.PostgreSQL.PQTypes.Internal.Connection

Documentation

newtype Connection

Wrapper for hiding representation of a connection object.

Constructors

Connection

Fields

• unConnection :: MVar (Maybe ConnectionData)

data ConnectionData

Representation of a connection object.

Constructors

ConnectionData

Fields

• cdFrgnPtr :: !(ForeignPtr (Ptr PGconn))

  Foreign pointer to pointer to connection object.

• cdPtr :: !(Ptr PGconn)

  Pointer to connection object (the same as in cdFrgnPtr).

• cdStats :: !ConnectionStats

  Statistics associated with the connection.

withConnectionData :: Connection -> String -> (ConnectionData -> IO (ConnectionData, r)) -> IO r

data ConnectionStats

Simple connection statistics.

Constructors

ConnectionStats

Fields

• statsQueries :: !Int

  Number of queries executed so far.

• statsRows :: !Int

  Number of rows fetched from the database.

• statsValues :: !Int

  Number of values fetched from the database.

• statsParams :: !Int

  Number of parameters sent to the database.

Instances

Eq ConnectionStats

Methods

(==) :: ConnectionStats -> ConnectionStats -> Bool

(/=) :: ConnectionStats -> ConnectionStats -> Bool

Ord ConnectionStats

Methods

compare :: ConnectionStats -> ConnectionStats -> Ordering

(<) :: ConnectionStats -> ConnectionStats -> Bool

(<=) :: ConnectionStats -> ConnectionStats -> Bool

(>) :: ConnectionStats -> ConnectionStats -> Bool

(>=) :: ConnectionStats -> ConnectionStats -> Bool

max :: ConnectionStats -> ConnectionStats -> ConnectionStats

min :: ConnectionStats -> ConnectionStats -> ConnectionStats

Show ConnectionStats

Methods

showsPrec :: Int -> ConnectionStats -> ShowS

show :: ConnectionStats -> String

showList :: [ConnectionStats] -> ShowS

data ConnectionSettings

Constructors

ConnectionSettings

Fields

• csConnInfo :: !Text

  Connection info string.

• csClientEncoding :: !(Maybe Text)

  Client-side encoding. If set to Nothing, database encoding is used.

• csComposites :: ![Text]

  A list of composite types to register. In order to be able to (de)serialize specific composite types, you need to register them.

Instances

Eq ConnectionSettings

Methods

(==) :: ConnectionSettings -> ConnectionSettings -> Bool

(/=) :: ConnectionSettings -> ConnectionSettings -> Bool

Ord ConnectionSettings

Methods

compare :: ConnectionSettings -> ConnectionSettings -> Ordering

(<) :: ConnectionSettings -> ConnectionSettings -> Bool

(<=) :: ConnectionSettings -> ConnectionSettings -> Bool

(>) :: ConnectionSettings -> ConnectionSettings -> Bool

(>=) :: ConnectionSettings -> ConnectionSettings -> Bool

max :: ConnectionSettings -> ConnectionSettings -> ConnectionSettings

min :: ConnectionSettings -> ConnectionSettings -> ConnectionSettings

Show ConnectionSettings

Methods

showsPrec :: Int -> ConnectionSettings -> ShowS

show :: ConnectionSettings -> String

showList :: [ConnectionSettings] -> ShowS

Default ConnectionSettings

Default connection settings. Note that all strings sent to PostgreSQL by the library are encoded as UTF-8, so don't alter client encoding unless you know what you're doing.

Methods

def :: ConnectionSettings

def :: Default a => a

The default value for this type.

newtype ConnectionSourceM m

Database connection supplier.

Constructors

ConnectionSourceM

Fields

• withConnection :: forall r. (Connection -> m r) -> m r

newtype ConnectionSource cs

Wrapper for a polymorphic connection source.

Constructors

ConnectionSource

Fields

• unConnectionSource :: forall m. MkConstraint m cs => ConnectionSourceM m

simpleSource :: ConnectionSettings -> ConnectionSource '[MonadBase IO, MonadMask]

Default connection supplier. It estabilishes new database connection each time withConnection is called.

poolSource

Arguments

:: ConnectionSettings

-> 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 database connection is kept open. The smallest acceptable value is 0.5 seconds.

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

-> Int

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

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

-> IO (ConnectionSource '[MonadBase IO, MonadMask])

Pooled source. It uses striped pool from resource-pool package to cache estabilished connections and reuse them.

connect :: ConnectionSettings -> IO Connection

Low-level function for connecting to the database. Useful if one wants to implement custom connection source.

disconnect :: Connection -> IO ()

Low-level function for disconnecting from the database. Useful if one wants to implement custom connection source.