practice: Database.Cassandra (using cassy)

Test.hs

{-# LANGUAGE OverloadedStrings #-}
module Main where

import Database.Cassandra.Basic
import System.Environment (getArgs)
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Instances ()
import Data.Binary (encode, decode)
import qualified Data.ByteString.Lazy.Char8 as BS (putStrLn)

keySpace :: KeySpace
keySpace = "test_keyspace"

columnFamily :: ColumnFamily
columnFamily = "user"

newServer :: String -> String -> Server
newServer h p = (h, read p)

main :: IO ()
main = do
  [host, port] <- getArgs
  pool <- createCassandraPool [newServer host port] 1 1 300 keySpace
  runCas pool $ do
    insert columnFamily "u999" QUORUM [col "name" "zzz", col "point" $ encode (999 :: Int)]
    getCol columnFamily "u999" ("name" :: String) QUORUM >>= liftIO . printName
    getCol columnFamily "u999" ("point" :: String) QUORUM >>= liftIO . printPoint

  -- XXX pool の開放はどうやるのか？

printName :: Maybe Column -> IO ()
printName c = case c of
                Just column -> do
                  let n = colVal column
                  BS.putStrLn n
                Nothing     -> putStrLn "not found"

printPoint :: Maybe Column -> IO ()
printPoint c = case c of
                Just column -> do
                  let p = decode $ colVal column :: Int
                  print p
                Nothing     -> putStrLn "not found"