module Database.RRDtool
( DataSource(..)
- , Expr(..)
+
+ , Expr
+ , CommonExpr
+ , IterativeExpr
+ , AggregativeExpr
+
+ , ExprSet
+ , CommonExprSet
+
+ , Constant(..)
+ , CommonUnaryOp(..)
+ , CommonBinaryOp(..)
+ , CommonTrinaryOp(..)
+ , CommonSetOp(..)
+ , IterativeValue(..)
+ , AggregativeUnaryOp(..)
+
, createRRD
)
where
+import Data.HList
import Data.Time.Clock
import Data.Time.Clock.POSIX
-- 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 where
- -- |GAUGE is for things like temperatures or number of people in a
- -- room or the value of a RedHat share.
- GAUGE :: {
+data DataSource
+ = -- |GAUGE is for things like temperatures or number of people in
+ -- a room or the value of a RedHat share.
+ GAUGE {
-- |The name you will use to reference this particular data
-- source from an RRD. A ds-name must be 1 to 19 characters
-- long in the characters @[a-zA-Z0-9_]@.
, dsMin :: !(Maybe Double)
-- |See 'dsMin'.
, dsMax :: !(Maybe Double)
- } -> DataSource
+ }
-- |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
-- 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 :: {
+ | COUNTER {
dsName :: !String
, dsHeartbeat :: !NominalDiffTime
, dsMin :: !(Maybe Double)
, dsMax :: !(Maybe Double)
- } -> DataSource
+ }
-- |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
-- 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 :: {
+ | DERIVE {
dsName :: !String
, dsHeartbeat :: !NominalDiffTime
, dsMin :: !(Maybe Double)
, dsMax :: !(Maybe Double)
- } -> DataSource
+ }
-- |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 :: {
+ | ABSOLUTE {
dsName :: !String
, dsHeartbeat :: !NominalDiffTime
, dsMin :: !(Maybe Double)
, dsMax :: !(Maybe Double)
- } -> DataSource
+ }
-- |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)
-- referred to as \"virtual\" or \"computed\" columns.
--
-- FIXME: doc links
- COMPUTE :: CommonExpr a => {
+ | forall a. CommonExpr a => COMPUTE {
dsName :: !String
-- |rpn-expression defines the formula used to compute the
-- PDPs of a COMPUTE data source from other data sources in
--
-- FIXME: doc links
, dsExpr :: !a
- } -> DataSource
+ }
dsTest :: DataSource
dsTest = COMPUTE {
dsName = "foo"
- , dsExpr = Var "foo" :<: Const 100
--- , dsExpr = Previous
+-- , dsExpr = Previous :<: Const 100
+-- , dsExpr = Var "foo" :<: Const 100
+ , dsExpr = Average (Const 100 .*. Const 200 .*. HNil)
}
-{-
-data Value
-data Expr r where
- (:<: ) :: Expr Value -> Expr Value -> Expr Bool
- (:<=:) :: Expr Value -> Expr Value -> Expr Bool
- (:>: ) :: Expr Value -> Expr Value -> Expr Bool
- (:>=:) :: Expr Value -> Expr Value -> Expr Bool
- (:==:) :: Expr Value -> Expr Value -> Expr Bool
- (:/=:) :: Expr Value -> Expr Value -> Expr Bool
- IsUnknown :: Expr Value -> Expr Bool
- IsInfinity :: Expr Value -> Expr Bool
- If :: Expr Bool -> Expr a -> Expr a -> Expr a
- Min :: Expr Value -> Expr Value -> Expr Value
- Max :: Expr Value -> Expr Value -> Expr Value
--}
-class Expr a
-class Expr a => CommonExpr a
-class Expr a => IterativeExpr a
-class Expr a => AggregativeExpr a
-instance CommonExpr a => IterativeExpr a
-instance CommonExpr a => AggregativeExpr a
+class Show e => Expr e
+class Expr e => CommonExpr e
+class Expr e => IterativeExpr e
+class Expr e => AggregativeExpr e
+instance CommonExpr e => IterativeExpr e
+instance CommonExpr e => AggregativeExpr e
+
+class (Show es, HList es) => ExprSet es
+instance ExprSet HNil
+instance (Expr e, ExprSet es) => ExprSet (HCons e es)
+
+class (Show es, HList es) => CommonExprSet es
+instance CommonExprSet es => ExprSet es
+instance CommonExprSet HNil
+instance (CommonExpr e, CommonExprSet es) => CommonExprSet (HCons e es)
+
-- Constants and variable names
-data Constant where
- Const :: !Double -> Constant
- Var :: !String -> Constant
+data Constant
+ = Const !Double
+ | Var !String
+ deriving (Show, Eq, Ord)
instance Expr Constant
instance CommonExpr Constant
-- Common operators
-data CommonBinaryOp a b where
- (:<: ) :: !a -> !b -> CommonBinaryOp a b
- (:<=:) :: !a -> !b -> CommonBinaryOp a b
-instance (Expr a, Expr b) => Expr (CommonBinaryOp a b)
-instance (CommonExpr a, CommonExpr b) => CommonExpr (CommonBinaryOp a b)
+data CommonUnaryOp a
+ = IsUnknown !a
+ | IsInfinity !a
+ | Sin !a
+ | Cos !a
+ | Log !a
+ | Exp !a
+ | Sqrt !a
+ | Atan !a
+ | Floor !a
+ | Ceil !a
+ | Deg2Rad !a
+ | Rad2Deg !a
+ | Abs !a
+ deriving (Show, Eq, Ord)
+instance Expr a => Expr (CommonUnaryOp a)
+instance CommonExpr a => CommonExpr (CommonUnaryOp a)
+
+data CommonBinaryOp a b
+ = !a :<: !b
+ | !a :<=: !b
+ | !a :>: !b
+ | !a :>=: !b
+ | !a :==: !b
+ | !a :/=: !b
+ | Min !a !b
+ | Max !a !b
+ | !a :+: !b
+ | !a :-: !b
+ | !a :*: !b
+ | !a :/: !b
+ | !a :%: !b
+ | AddNaN !a !b
+ | AtanXY !a !b
+ deriving (Show, Eq, Ord)
+instance (Expr a, Expr b)
+ => Expr (CommonBinaryOp a b)
+instance (CommonExpr a, CommonExpr b)
+ => CommonExpr (CommonBinaryOp a b)
+
+data CommonTrinaryOp a b c
+ = If !a !b !c
+ | Limit !a !b !c
+ deriving (Show, Eq, Ord)
+instance (Expr a, Expr b, Expr c)
+ => Expr (CommonTrinaryOp a b c)
+instance (CommonExpr a, CommonExpr b, CommonExpr c)
+ => CommonExpr (CommonTrinaryOp a b c)
+
+-- SORT and REV can't be expressed in this way as they pushes possibly
+-- multiple values onto the stack...
+
+data CommonSetOp es
+ = Average !es
+ deriving (Show, Eq, Ord)
+instance ExprSet es => Expr (CommonSetOp es)
+instance CommonExprSet es => CommonExpr (CommonSetOp es)
-- Iterative special values
-data IterativeValue where
- Previous :: IterativeValue
+data IterativeValue
+ = Previous
+ deriving (Show, Eq, Ord)
instance Expr IterativeValue
instance IterativeExpr IterativeValue
-- Aggregative operators
-data AggregativeUnaryOp a where
- Maximum :: !a -> AggregativeUnaryOp a
+data AggregativeUnaryOp a
+ = Maximum !a
+ deriving (Show, Eq, Ord)
instance Expr a => Expr (AggregativeUnaryOp a)
instance AggregativeExpr a => AggregativeExpr (AggregativeUnaryOp a)
projects / hs-rrdtool.git / commitdiff