From 1857169713e2047ff16427f4f2add96a0251035b Mon Sep 17 00:00:00 2001 From: PHO Date: Tue, 20 Apr 2010 23:17:13 +0900 Subject: [PATCH] wip --- Database/RRDtool.hs | 176 ++++++++++++++++++++++++++++---------------- rrdtool.cabal | 8 ++ 2 files changed, 121 insertions(+), 63 deletions(-) diff --git a/Database/RRDtool.hs b/Database/RRDtool.hs index 7ffef44..ca842a4 100644 --- a/Database/RRDtool.hs +++ b/Database/RRDtool.hs @@ -33,10 +33,10 @@ 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 - = -- |GAUGE is for things like temperatures or number of people in - -- a room or the value of a RedHat share. - GAUGE { +data DataSource where + -- |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_]@. @@ -61,79 +61,129 @@ data DataSource , 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 { + } -> 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 + -- 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 { + } -> 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 + -- 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 { + } -> 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 :: { 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 - | COMPUTE { + } -> 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) + -- 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 + COMPUTE :: CommonExpr a => { dsName :: !String - -- |rpn-expression defines the formula used to compute the PDPs - -- of a COMPUTE data source from other data sources in the same - -- \. It is similar to defining a CDEF argument for the - -- graph command. For COMPUTE data sources, the following RPN - -- operations are not supported: COUNT, PREV, TIME, and - -- LTIME. In addition, in defining the RPN expression, the - -- COMPUTE data source may only refer to the names of data - -- source listed previously in the create command. This is - -- similar to the restriction that CDEFs must refer only to DEFs - -- and CDEFs previously defined in the same graph command. - -- - -- FIXME: doc links - , dsExpr :: !Expr - } - deriving (Eq, Ord, Show) + -- |rpn-expression defines the formula used to compute the + -- PDPs of a COMPUTE data source from other data sources in + -- the same \. It is similar to defining a CDEF argument + -- for the graph command. For COMPUTE data sources, the + -- following RPN operations are not supported: COUNT, PREV, + -- TIME, and LTIME. In addition, in defining the RPN + -- expression, the COMPUTE data source may only refer to the + -- names of data source listed previously in the create + -- command. This is similar to the restriction that CDEFs must + -- refer only to DEFs and CDEFs previously defined in the same + -- graph command. + -- + -- FIXME: doc links + , dsExpr :: !a + } -> DataSource -data Expr - = UNK - deriving (Show, Eq, Ord) +dsTest :: DataSource +dsTest = COMPUTE { + dsName = "foo" + , dsExpr = Var "foo" :<: Const 100 +-- , dsExpr = Previous + } + +{- +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 + +-- Constants and variable names +data Constant where + Const :: !Double -> Constant + Var :: !String -> Constant +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) + +-- Iterative special values +data IterativeValue where + Previous :: IterativeValue +instance Expr IterativeValue +instance IterativeExpr IterativeValue + +-- Aggregative operators +data AggregativeUnaryOp a where + Maximum :: !a -> AggregativeUnaryOp a +instance Expr a => Expr (AggregativeUnaryOp a) +instance AggregativeExpr a => AggregativeExpr (AggregativeUnaryOp a) -- |The 'createRRD' function lets you set up new Round Robin Database -- (RRD) files. The file is created at its final, full size and filled diff --git a/rrdtool.cabal b/rrdtool.cabal index d590e19..900e4c2 100644 --- a/rrdtool.cabal +++ b/rrdtool.cabal @@ -27,5 +27,13 @@ Library bindings-librrd == 0.1.*, time == 1.1.* + Extensions: + EmptyDataDecls + FlexibleInstances + GADTs + TypeOperators + TypeSynonymInstances + UndecidableInstances + Exposed-Modules: Database.RRDtool -- 2.40.0