diff --git a/Database/Redis/Simple.hs b/Database/Redis/Simple.hs new file mode 100644 --- /dev/null +++ b/Database/Redis/Simple.hs @@ -0,0 +1,127 @@ +-- | This module is meant to make working with redis in Haskell more simple. It +-- is a small layer above the full-blown @redis@ package. +-- +-- It only supports a small subset of the redis features. +-- +{-# LANGUAGE OverloadedStrings, GeneralizedNewtypeDeriving #-} +module Database.Redis.Simple + ( -- * Type for keys + Key (..) + + -- * Working with simple key-value pairs + , itemGet + , itemExists + , itemSet + , itemDelete + + -- * Working with sets + , setAdd + , setRemove + , setContains + , setFindAll + ) where + +import Control.Applicative ((<$>)) +import Data.Maybe (catMaybes) +import Data.Monoid (Monoid) +import Data.ByteString (ByteString) +import GHC.Exts (IsString) +import Data.Binary (Binary, encode, decode) + +import Database.Redis.Redis + +-- | Type for a key in the key-value store +-- +newtype Key = Key {unKey :: ByteString} + deriving (Show, Eq, Ord, IsString, Monoid, Binary) + +-- | Gets an item from the database +-- +itemGet :: Binary a + => Redis -- ^ Redis handle + -> Key -- ^ Key of the value to get + -> IO (Maybe a) -- ^ Resulting value +itemGet redis key = do + reply <- get redis $ unKey key + return $ case reply of RBulk (Just r) -> Just $ decode r + _ -> Nothing + +-- | Checks if an item with a given key exists +-- +itemExists :: Redis -- ^ Redis handle + -> Key -- ^ Key to test + -> IO Bool -- ^ If the key exists +itemExists redis (Key key) = do + reply <- exists redis key + return $ case reply of RInt 1 -> True + _ -> False + +-- | Set an item in the database +-- +itemSet :: Binary a + => Redis -- ^ Redis handle + -> Key -- ^ Key + -> a -- ^ Value + -> IO () -- ^ No result +itemSet redis (Key key) item = do + _ <- set redis key (encode item) + return () + +-- | Delete an item in the database +-- +itemDelete :: Redis -- ^ Redis handle + -> Key -- ^ Key + -> IO () -- ^ No result +itemDelete redis (Key key) = do + _ <- del redis key + return () + +-- | Add an item to a redis set +-- +setAdd :: Binary a + => Redis -- ^ Redis handle + -> Key -- ^ Key of the set + -> a -- ^ Item to add to the set + -> IO () -- ^ No result +setAdd redis (Key s) m = do + _ <- sadd redis s $ encode m + return () + +-- | Remove an item from a redis set +-- +setRemove :: Binary a + => Redis -- ^ Redis handle + -> Key -- ^ Key of the set + -> a -- ^ Item to remove from the set + -> IO () -- ^ No result +setRemove redis (Key s) m = do + _ <- srem redis s $ encode m + return () + +-- | Check if a set contains a certain item +-- +setContains :: Binary a + => Redis -- ^ Redis handle + -> Key -- ^ Key of the set + -> a -- ^ Item to check for + -> IO Bool -- ^ If the item is present in the set +setContains redis (Key s) m = do + reply <- sismember redis s $ encode m + return $ case reply of + RInt 1 -> True + _ -> False + +-- | Get all items from a set +-- +setFindAll :: Binary a + => Redis -- ^ Redis handle + -> Key -- ^ Key of the set + -> IO [a] -- ^ All items in the set +setFindAll redis (Key s) = do + reply <- smembers redis s + case reply of + RMulti (Just replies) -> + return $ catMaybes $ flip map replies $ \r -> case r of + RBulk i -> decode <$> i + _ -> Nothing + _ -> return [] diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +Copyright Jasper Van der Jeugt 2010 + +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following + disclaimer in the documentation and/or other materials provided + with the distribution. + + * Neither the name of Jasper Van der Jeugt nor the names of other + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/redis-simple.cabal b/redis-simple.cabal new file mode 100644 --- /dev/null +++ b/redis-simple.cabal @@ -0,0 +1,28 @@ +Name: redis-simple +Version: 0.1 +Synopsis: Simple redis bindings for Haskell +Description: This package is meant to simplify usage of redis in + Haskell. It is built on the full-blown @redis@ package + and, in fact, does nothing more than providing an easier + interface to a small subset of it's functions. +Homepage: http://github.com/jaspervdj/redis-simple +Bug-Reports: http://github.com/jaspervdj/redis-simple/issues +License: BSD3 +License-file: LICENSE +Author: Jasper Van der Jeugt +Maintainer: jaspervdj@gmail.com +Stability: Experimental +Category: Text +Build-type: Simple +Cabal-version: >=1.2 +Library + Ghc-Options: -Wall + + -- Modules exported by the library. + Exposed-modules: Database.Redis.Simple + + -- Packages needed in order to build this package. + Build-depends: base >= 4 && < 5, + redis >= 0.7, + bytestring >= 0.9, + binary >= 0.5