Data.ConnectionPool.Internal.ResourcePoolParams

Internal packages are here to provide access to internal definitions for library writers, but they should not be used in application code.

Preferably use qualified import, e.g.:

import qualified Data.ConnectionPool.Internal.ResourcePoolParams
  as Internal

Surprisingly this module doesn't depend on resource-pool package and it would be good if it stayed that way, but not at the cost of crippling functionality.

Importantly this package should not depend on streaming-commons package or other modules of this package.

Please, bear above in mind when doing modifications.

ResourcePoolParams

data ResourcePoolParams

Parameters of resource pool that describe things like its internal structure. See createPool for details.

Instance for Generic introduced in version 0.2.

Constructors

ResourcePoolParams

Fields

_numberOfStripes :: !Int

_resourceIdleTimeout :: !NominalDiffTime

_numberOfResourcesPerStripe :: !Int

Instances

Data ResourcePoolParams

Show ResourcePoolParams

Generic ResourcePoolParams

Default ResourcePoolParams

numberOfStripes = 1
resourceIdleTimeout = 0.5
numberOfResourcesPerStripe = 1

type Rep ResourcePoolParams

Lenses

numberOfResourcesPerStripe :: Functor f => (Int -> f Int) -> ResourcePoolParams -> f ResourcePoolParams

Lens for accessing maximum number of resources to keep open per stripe. The smallest acceptable value is 1 (default).

numberOfStripes :: Functor f => (Int -> f Int) -> ResourcePoolParams -> f ResourcePoolParams

Lens for accessing stripe count. The number of distinct sub-pools to maintain. The smallest acceptable value is 1 (default).

resourceIdleTimeout :: Functor f => (NominalDiffTime -> f NominalDiffTime) -> ResourcePoolParams -> f ResourcePoolParams

Lens for accessing amount of time for which an unused resource is kept open. The smallest acceptable value is 0.5 seconds (default).

Validation

validateResourcePoolParams

Arguments

:: ResourcePoolParams

Parameters to validate.

-> Either String ResourcePoolParams

Either error message or the same value of ResourcePoolParams passed as a first argument.

Check if all parameters for underlying resource pool are valid:

• numberOfStripes >= 1 Number of connection sub-pools. Keeping it set to 1 is good for most applications.
• numberOfResourcesPerStripe >= 1 Maximum number of connections in each stripe. Totally there can be numberOfStripes * numberOfResourcesPerStripe open connections simultaneously.
• resourceIdleTimeout >= 0.5 Property specified for how long connection will be kept alive after it is released by back to the pool before it is automatically closed. Value is in seconds.

For more details see createPool.

Since version 0.1.1.0.