module Data.HList
- ( HList
+ ( -- Data.HList.Prelude
+ HList
, HNil(..)
, hNil
, (:*:)(..)
, (.*.)
- , HExtendable(..)
- , HAppendable(..)
+ , (:++:)
+ , (.++.)
, Applyable(..)
- , Applyable2(..)
- , Id(..)
- , ApplyHAppend(..)
-
- , HFoldrable(..)
- , HConcatable(..)
- , HMappable(..)
+ , HConcat
+ , HMap
)
where
-import Data.Typeable
-
--- HList
-class HList l
-
--- HNil
-data HNil
- = HNil
- deriving (Show, Eq, Ord, Read, Typeable)
-
-instance HList HNil
-
-hNil :: HNil
-hNil = HNil
-
--- :*:
-infixr 2 :*:
-infixr 2 .*.
-
-data e :*: l
- = e :*: l
- deriving (Show, Eq, Ord, Read, Typeable)
-
-instance HList l => HList (e :*: l)
-
-(.*.) :: HList l => e -> l -> e :*: l
-(.*.) = (:*:)
-
--- HExtendable
-class HExtendable e l where
- type HExtend e l
- hExtend :: e -> l -> HExtend e l
-
-instance HExtendable e HNil where
- type HExtend e HNil = e :*: HNil
- hExtend e nil = e .*. nil
-
-instance HList l => HExtendable e (e' :*: l) where
- type HExtend e (e' :*: l) = e :*: e' :*: l
- hExtend e (e' :*: l) = e .*. e' .*. l
-
--- HAppendable
-infixr 1 :++:
-infixr 1 .++.
-
-class HAppendable l l' where
- type l :++: l'
- (.++.) :: l -> l' -> l :++: l'
-
-instance HList l => HAppendable HNil l where
- type HNil :++: l = l
- _ .++. l = l
-
-instance ( HAppendable l l'
- , HList (l :++: l')
- ) => HAppendable (e :*: l) l' where
- type (e :*: l) :++: l' = e :*: (l :++: l')
- (e :*: l) .++. l' = e .*. (l .++. l')
-
--- Applyable
-class Applyable f a where
- type Apply f a
- apply :: f -> a -> Apply f a
-
--- Applyable2
-class Applyable2 f a b where
- type Apply2 f a b
- apply2 :: f -> a -> b -> Apply2 f a b
-
--- Id
-data Id = Id
-
-instance Applyable Id a where
- type Apply Id a = a
- apply _ a = a
-
--- ApplyHAppend
-data ApplyHAppend = ApplyHAppend
-
-instance HAppendable a b => Applyable2 ApplyHAppend a b where
- type Apply2 ApplyHAppend a b = a :++: b
- apply2 _ a b = a .++. b
-
--- HFoldrable
-class HFoldrable f v l where
- type HFoldr f v l
- hFoldr :: f -> v -> l -> HFoldr f v l
-
-instance HFoldrable f v HNil where
- type HFoldr f v HNil = v
- hFoldr _ v _ = v
-
-instance ( HFoldrable f v l
- , Applyable2 f e (HFoldr f v l)
- ) => HFoldrable f v (e :*: l) where
- type HFoldr f v (e :*: l) = Apply2 f e (HFoldr f v l)
- hFoldr f v (e :*: l) = apply2 f e (hFoldr f v l)
-
--- HConcatable
-class HConcatable ls where
- type HConcat ls
- hConcat :: ls -> HConcat ls
-
-instance HFoldrable ApplyHAppend HNil ls => HConcatable ls where
- type HConcat ls = HFoldr ApplyHAppend HNil ls
- hConcat ls = hFoldr ApplyHAppend hNil ls
-
--- HMappable
-class HMappable f l where
- type HMap f l
- hMap :: f -> l -> HMap f l
-
-instance HMappable f HNil where
- type HMap f HNil = HNil
- hMap _ _ = HNil
-
-instance ( HList (HMap f xs)
- , Applyable f x
- , HMappable f xs
- ) => HMappable f (x :*: xs) where
- type HMap f (x :*: xs) = Apply f x :*: HMap f xs
- hMap f (x :*: xs) = apply f x .*. hMap f xs
+import Data.HList.Prelude
--- /dev/null
+module Data.HList.Prelude
+ ( HList
+ , HNil(..)
+ , hNil
+ , (:*:)(..)
+ , (.*.)
+
+ , HExtendable(..)
+ , HAppendable(..)
+
+ , Applyable(..)
+ , Applyable2(..)
+
+ , Id(..)
+ , ApplyHAppend(..)
+
+ , HFoldrable(..)
+ , HConcatable(..)
+ , HMappable(..)
+ )
+ where
+
+import Data.Typeable
+
+
+-- HList
+class HList l
+
+-- HNil
+data HNil
+ = HNil
+ deriving (Show, Eq, Ord, Read, Typeable)
+
+instance HList HNil
+
+hNil :: HNil
+hNil = HNil
+
+-- :*:
+infixr 2 :*:
+infixr 2 .*.
+
+data e :*: l
+ = e :*: l
+ deriving (Show, Eq, Ord, Read, Typeable)
+
+instance HList l => HList (e :*: l)
+
+(.*.) :: HList l => e -> l -> e :*: l
+(.*.) = (:*:)
+
+-- HExtendable
+class HExtendable e l where
+ type HExtend e l
+ hExtend :: e -> l -> HExtend e l
+
+instance HExtendable e HNil where
+ type HExtend e HNil = e :*: HNil
+ hExtend e nil = e .*. nil
+
+instance HList l => HExtendable e (e' :*: l) where
+ type HExtend e (e' :*: l) = e :*: e' :*: l
+ hExtend e (e' :*: l) = e .*. e' .*. l
+
+-- HAppendable
+infixr 1 :++:
+infixr 1 .++.
+
+class HAppendable l l' where
+ type l :++: l'
+ (.++.) :: l -> l' -> l :++: l'
+
+instance HList l => HAppendable HNil l where
+ type HNil :++: l = l
+ _ .++. l = l
+
+instance ( HAppendable l l'
+ , HList (l :++: l')
+ ) => HAppendable (e :*: l) l' where
+ type (e :*: l) :++: l' = e :*: (l :++: l')
+ (e :*: l) .++. l' = e .*. (l .++. l')
+
+-- Applyable
+class Applyable f a where
+ type Apply f a
+ apply :: f -> a -> Apply f a
+
+-- Applyable2
+class Applyable2 f a b where
+ type Apply2 f a b
+ apply2 :: f -> a -> b -> Apply2 f a b
+
+-- Id
+data Id = Id
+
+instance Applyable Id a where
+ type Apply Id a = a
+ apply _ a = a
+
+-- ApplyHAppend
+data ApplyHAppend = ApplyHAppend
+
+instance HAppendable a b => Applyable2 ApplyHAppend a b where
+ type Apply2 ApplyHAppend a b = a :++: b
+ apply2 _ a b = a .++. b
+
+-- HFoldrable
+class HFoldrable f v l where
+ type HFoldr f v l
+ hFoldr :: f -> v -> l -> HFoldr f v l
+
+instance HFoldrable f v HNil where
+ type HFoldr f v HNil = v
+ hFoldr _ v _ = v
+
+instance ( HFoldrable f v l
+ , Applyable2 f e (HFoldr f v l)
+ ) => HFoldrable f v (e :*: l) where
+ type HFoldr f v (e :*: l) = Apply2 f e (HFoldr f v l)
+ hFoldr f v (e :*: l) = apply2 f e (hFoldr f v l)
+
+-- HConcatable
+class HConcatable ls where
+ type HConcat ls
+ hConcat :: ls -> HConcat ls
+
+instance HFoldrable ApplyHAppend HNil ls => HConcatable ls where
+ type HConcat ls = HFoldr ApplyHAppend HNil ls
+ hConcat ls = hFoldr ApplyHAppend hNil ls
+
+-- HMappable
+class HMappable f l where
+ type HMap f l
+ hMap :: f -> l -> HMap f l
+
+instance HMappable f HNil where
+ type HMap f HNil = HNil
+ hMap _ _ = HNil
+
+instance ( HList (HMap f xs)
+ , Applyable f x
+ , HMappable f xs
+ ) => HMappable f (x :*: xs) where
+ type HMap f (x :*: xs) = Apply f x :*: HMap f xs
+ hMap f (x :*: xs) = apply f x .*. hMap f xs
module Database.RRDtool.Create
- ( DataSource(..)
+ ( DataSource
+ , ExternalDSType(..)
+ , ExternalDataSource(..)
+ , ComputedDataSource(..)
, createRRD
-- Data.HList
-- 32bit counter, DERIVE with @'dsMin' = 0@ is probably preferable. If
-- you are using a 64bit counter, just about any max setting will
-- eliminate the possibility of mistaking a reset for a counter wrap.
-data DataSource
- = -- |GAUGE is for things like temperatures or number of people in
- -- a room or the value of a RedHat share.
- GAUGE {
+class DataSource ds
+
+data ExternalDSType
+ = GAUGE -- ^GAUGE is for things like temperatures or number of
+ -- people in a room or the value of a RedHat share.
+ | COUNTER -- ^COUNTER is for continuous incrementing counters
+ -- like the ifInOctets counter in a router. The COUNTER
+ -- data source assumes that the counter never
+ -- decreases, except when a counter overflows. The
+ -- update function takes the overflow into account. The
+ -- counter is stored as a per-second rate. When the
+ -- counter overflows, RRDtool checks if the overflow
+ -- happened at the 32bit or 64bit border and acts
+ -- accordingly by adding an appropriate value to the
+ -- result.
+ | DERIVE -- ^DERIVE will store the derivative of the line going
+ -- from the last to the current value of the data
+ -- source. This can be useful for gauges, for example,
+ -- to measure the rate of people entering or leaving a
+ -- room. Internally, derive works exactly like COUNTER
+ -- but without overflow checks. So if your counter does
+ -- not reset at 32 or 64 bit you might want to use
+ -- DERIVE and combine it with a 'dsMin' value of 0.
+ | ABSOLUTE -- ^ABSOLUTE is for counters which get reset upon
+ -- reading. This is used for fast counters which tend
+ -- to overflow. So instead of reading them normally you
+ -- reset them after every read to make sure you have a
+ -- maximum time available before the next
+ -- overflow. Another usage is for things you count like
+ -- number of messages since the last update.
+ deriving (Show, Eq, Ord)
+
+instance DataSource ExternalDSType
+
+data ExternalDataSource
+ = ExternalDataSource {
-- |The name you will use to reference this particular data
- -- source from an RRD. A ds-name must be 1 to 19 characters
+ -- source from an RRD. A ds name must be 1 to 19 characters
-- long in the characters @[a-zA-Z0-9_]@.
- dsName :: !String
- -- |Defines the maximum number of seconds that may
- -- pass between two updates of this data source before the
- -- value of the data source is assumed to be @*UNKNOWN*@.
- , dsHeartbeat :: !NominalDiffTime
- -- |'dsMin' and 'dsMax' Define the expected range values for
- -- data supplied by a data source. If 'dsMin' and\/or 'dsMax'
+ edsName :: !String
+ -- |The type of this data source.
+ , edsType :: !ExternalDSType
+ -- |Defines the maximum number of seconds that may pass
+ -- between two updates of this data source before the value of
+ -- the data source is assumed to be @*UNKNOWN*@.
+ , edsHeartbeat :: !NominalDiffTime
+ -- |'edsMin' and 'edsMax' Define the expected range values for
+ -- data supplied by a data source. If 'edsMin' and\/or 'edsMax'
-- any value outside the defined range will be regarded as
- -- @*UNKNOWN*@. If you do not know or care about 'dsMin' and
- -- 'dsMax', set them to 'Nothing' for unknown. Note that
- -- 'dsMin' and 'dsMax' always refer to the processed values of
+ -- @*UNKNOWN*@. If you do not know or care about 'edsMin' and
+ -- 'edsMax', set them to 'Nothing' for unknown. Note that
+ -- 'edsMin' and 'edsMax' always refer to the processed values of
-- the DS. For a traffic-'COUNTER' type DS this would be the
-- maximum and minimum data-rate expected from the device.
--
-- available, always set the min and\/or max properties. This
-- will help RRDtool in doing a simple sanity check on the
-- data supplied when running update.
- , dsMin :: !(Maybe Double)
- -- |See 'dsMin'.
- , dsMax :: !(Maybe Double)
- }
- -- |COUNTER is for continuous incrementing counters like the
- -- ifInOctets counter in a router. The COUNTER data source assumes
- -- that the counter never decreases, except when a counter
- -- overflows. The update function takes the overflow into
- -- account. The counter is stored as a per-second rate. When the
- -- counter overflows, RRDtool checks if the overflow happened at
- -- the 32bit or 64bit border and acts accordingly by adding an
- -- appropriate value to the result.
- | COUNTER {
- dsName :: !String
- , dsHeartbeat :: !NominalDiffTime
- , dsMin :: !(Maybe Double)
- , dsMax :: !(Maybe Double)
- }
- -- |DERIVE will store the derivative of the line going from the
- -- last to the current value of the data source. This can be
- -- useful for gauges, for example, to measure the rate of people
- -- entering or leaving a room. Internally, derive works exactly
- -- like COUNTER but without overflow checks. So if your counter
- -- does not reset at 32 or 64 bit you might want to use DERIVE and
- -- combine it with a 'dsMin' value of 0.
- | DERIVE {
- dsName :: !String
- , dsHeartbeat :: !NominalDiffTime
- , dsMin :: !(Maybe Double)
- , dsMax :: !(Maybe Double)
- }
- -- |ABSOLUTE is for counters which get reset upon reading. This is
- -- used for fast counters which tend to overflow. So instead of
- -- reading them normally you reset them after every read to make
- -- sure you have a maximum time available before the next
- -- overflow. Another usage is for things you count like number of
- -- messages since the last update.
- | ABSOLUTE {
- dsName :: !String
- , dsHeartbeat :: !NominalDiffTime
- , dsMin :: !(Maybe Double)
- , dsMax :: !(Maybe Double)
- }
- -- |COMPUTE is for storing the result of a formula applied to
- -- other data sources in the RRD. This data source is not supplied
- -- a value on update, but rather its Primary Data Points (PDPs)
- -- are computed from the PDPs of the data sources according to the
- -- rpn-expression that defines the formula. Consolidation
- -- functions are then applied normally to the PDPs of the COMPUTE
- -- data source (that is the rpn-expression is only applied to
- -- generate PDPs). In database software, such data sets are
- -- referred to as \"virtual\" or \"computed\" columns.
- --
- -- FIXME: doc links
- | forall a. IsCommonExpr a => COMPUTE {
- dsName :: !String
+ , edsMin :: !(Maybe Double)
+ -- |See 'edsMin'.
+ , edsMax :: !(Maybe Double)
+ }
+ deriving (Show, Eq, Ord)
+
+
+-- |ComputedDataSource is for storing the result of a formula applied
+-- to other data sources in the RRD. This data source is not supplied
+-- a value on update, but rather its Primary Data Points (PDPs) are
+-- computed from the PDPs of the data sources according to the
+-- rpn-expression that defines the formula. Consolidation functions
+-- are then applied normally to the PDPs of the COMPUTE data source
+-- (that is the rpn-expression is only applied to generate PDPs). In
+-- database software, such data sets are referred to as \"virtual\" or
+-- \"computed\" columns.
+--
+-- FIXME: doc links
+data ComputedDataSource e
+ = ComputedDataSource {
+ -- |See 'edsName'
+ cdsName :: !String
-- |rpn-expression defines the formula used to compute the
-- PDPs of a COMPUTE data source from other data sources in
-- the same \<RRD\>. It is similar to defining a CDEF argument
-- graph command.
--
-- FIXME: doc links
- , dsExpr :: !a
+ , cdsExpr :: !e
}
+ deriving (Show, Eq, Ord)
+
+instance IsCommonExpr e => DataSource (ComputedDataSource e)
+
-dsTest :: DataSource
-dsTest = COMPUTE {
- dsName = "foo"
--- , dsExpr = Previous :<: Const 100
--- , dsExpr = Var "foo" :<: Const 100
- , dsExpr = AverageOf (Const 100 .*. Const 200 .*. HNil)
+dsTest = ComputedDataSource {
+ cdsName = "foo"
+-- , dsExpr = Previous :<: Const 100
+-- , dsExpr = Var "foo" :<: Const 100
+ , cdsExpr = AverageOf (Const 100 .*. Const 200 .*. HNil)
}
-- |The 'createRRD' function lets you set up new Round Robin Database
-> Maybe NominalDiffTime -- ^Specifies the base interval in
-- seconds with which data will be fed
-- into the RRD. (default: 300 sec)
- -> [DataSource] -- ^Data sources to accept input from.
+-- -> [DataSource] -- ^Data sources to accept input from.
-> IO ()
createRRD = error "FIXME"
projects / hs-rrdtool.git / commitdiff