Data.TCache.TMVar.Dynamic: A dynamic interface for TCache using TMVars
Dynamic present essentially the same methods than Data.TCache. The added functionality is the management of IDynamic types. Any datatype that is instance of IResource and Typeable can be handled mixed with any other datatype. TCache.Dynamic is essentially a TCache working with a single datatype: IDynamic that is indexable and serializable. You dont need to do anything special except to define the IResource and typeable instances for your particular datatype. Also, before use, your datatype must be registered (with registerType, see example in the package).
there are basically two types of methods:
- *Resource(s) : manage one type of data, Are the same than Data.TCache. The marsalling to and from IDynamic is managed internally
- *DResource(s): handle the IDynamic type. you must wrap your datatype (with toIDyn) and unwap it (with fromIDyn)
The first set allows different modules to handle their particular kind of data without regard that it is being handled in the same cache with other datatypes.
The second set allows to handle, transact etc with many datatypes at the same time.
There is also a useful Key object whose purpose is to retrieve any objecto fo any datatype by its sting key
Also the parameter refcache has been dropped from the methods that used it (the syncronization methods)
- class IResource a where
- keyResource :: a -> String
- serialize :: a -> String
- deserialize :: String -> a
- tshowp :: a -> ST String
- treadp :: ST a
- defPath :: a -> String
- readResource :: a -> IO (Maybe a)
- writeResource :: a -> IO ()
- delResource :: a -> IO ()
- data Resources a b
- resources :: Resources a ()
- setCache :: (Ht a, Integer) -> IO ()
- refcache :: Cache a
- defaultCheck :: Integer -> Integer -> Integer -> Bool
- readFileStrict :: FilePath -> IO [Char]
- data IDynamic = forall a . (Typeable a, IResource a) => IDynamic a
- type Cache a = IORef (Ht a, Integer)
- class DynamicInterface x where
- toIDyn :: x -> IDynamic
- registerType :: IO x
- fromIDyn :: IDynamic -> x
- unsafeFromIDyn :: IDynamic -> x
- data Key = Key TypeRep String
- getTMVars :: [IDynamic] -> STM [Maybe (TMVar IDynamic)]
- getTMVarsIO :: [IDynamic] -> IO [TMVar IDynamic]
- withDResource :: IDynamic -> (Maybe IDynamic -> IDynamic) -> IO ()
- withDResources :: [IDynamic] -> ([Maybe IDynamic] -> [IDynamic]) -> IO ()
- withDSTMResources :: [IDynamic] -> ([Maybe IDynamic] -> Resources IDynamic x) -> STM x
- getDResource :: IDynamic -> IO (Maybe IDynamic)
- getDResources :: [IDynamic] -> IO [Maybe IDynamic]
- deleteDResource :: IDynamic -> IO ()
- deleteDResources :: [IDynamic] -> IO ()
- syncCache :: IO ()
- clearSyncCacheProc :: Int -> (Integer -> Integer -> Integer -> Bool) -> Int -> IO ThreadId
- withResource :: (Typeable a, Typeable b, IResource a, IResource b) => a -> (Maybe a -> b) -> IO ()
- withResources :: (Typeable a, Typeable b, IResource a, IResource b) => [a] -> ([Maybe a] -> [b]) -> IO ()
- withSTMResources :: forall x a b. (Typeable a, Typeable b, IResource a, IResource b) => [a] -> ([Maybe a] -> Resources b x) -> STM x
- getResource :: (Typeable a, Typeable b, IResource a, IResource b) => a -> IO (Maybe b)
- getResources :: (Typeable a, Typeable b, IResource a, IResource b) => [a] -> IO [Maybe b]
- deleteResource :: (Typeable a, IResource a) => a -> IO ()
- deleteResources :: (Typeable a, IResource a) => [a] -> IO ()
Documentation
Interface that must be defined for every object being cached.
readResource
and writeResource
are implemented by default as read-write to files with its key as filename
serialize
and deserialize
are specified just to allow these defaults. If you define your own persistence, then
serialize
and deserialize
are not needed. The package Workflow
need them anyway.
minimal definition: keyResource, serialize, deserialize
While serialize and deserialize are agnostic about the way of converison to strings, either binary or textual, treadp and tshowp use the monad defined in the RefSerialize package. Both ways of serialization are alternative. one is defined by default in terms of the other. the RefSerialize monad has been introduced to permit IResource objects to be serialized as part of larger structures that embody them. This is necessary for the Workdlow package.
The keyResource string must be a unique since this is used to index it in the hash table. when accessing a resource, the user must provide a partial object for wich the key can be obtained. for example:
data Person= Person{name, surname:: String, account :: Int ....) keyResource Person n s ...= n++s
the data being accesed must have the fields used by keyResource filled. For example
readResource Person {name=John, surname= Adams}
leaving the rest of the fields undefined
IResource has defaults definitions for all the methods except keyResource Either one or other serializer must be defiened for default witeResource, readResource and delResource
:: a | |
-> String | must be defined |
:: a | |
-> String | must be defined by the user |
:: String | |
-> a | must be defined by the user |
:: a | |
-> ST String | serializer in the |
:: ST a | deserialize in the RefSerilzlize monad. |
:: a | |
-> String | additional extension for default file paths or key prefixes |
readResource :: a -> IO (Maybe a)Source
writeResource :: a -> IO ()Source
delResource :: a -> IO ()Source
Resources returned by withSTMResources'
setCache :: (Ht a, Integer) -> IO ()Source
set the cache. this is useful for hot loaded modules that will update an existing cache
defaultCheck :: Integer -> Integer -> Integer -> BoolSource
To drop from the cache all the elems not accesed since half the time between now and the last sync the default check procedure :: Integer -- current time in seconds -> Integer --last access time for a given object -> Integer --last cache syncronization (with the persisten storage) -> Bool --return true for all the elems not accesed since half the time between now and the last sync
readFileStrict :: FilePath -> IO [Char]Source
class DynamicInterface x whereSource
DynamicInterface groups a set of default method calls to handle dynamic objects. It is not necessary to derive instances from it
:: x | |
-> IDynamic | encapsulates data in a dynamic object |
:: IO x | registers the deserialize, readp and readResource methods for this data type |
:: IDynamic | |
-> x | extract the data from the dynamic object. trows a user error when the cast fails |
:: IDynamic | |
-> x | unsafe version. |
(IResource x, Typeable x) => DynamicInterface x |
deleteDResource :: IDynamic -> IO ()Source
return error if any resource is not found
deleteDResources :: [IDynamic] -> IO ()Source
withResource :: (Typeable a, Typeable b, IResource a, IResource b) => a -> (Maybe a -> b) -> IO ()Source
withResources :: (Typeable a, Typeable b, IResource a, IResource b) => [a] -> ([Maybe a] -> [b]) -> IO ()Source