diff --git a/CHANGELOG.md b/CHANGELOG.md --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -4,6 +4,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html). +## 0.2.0 +### Changed +- Accept read options instead of snapshot for read operations. + ## 0.1.4 ### Changed - Documentation improvements. diff --git a/rocksdb-query.cabal b/rocksdb-query.cabal --- a/rocksdb-query.cabal +++ b/rocksdb-query.cabal @@ -2,10 +2,10 @@ -- -- see: https://github.com/sol/hpack -- --- hash: 6a197506c4da781d1961464f87333cda5a6687a1432fa0586d8cf4eadc50b1ed +-- hash: bcc5b994097bfd7c7418a70ade182d3fc5c268d6b4667e658cb0e5de7727a910 name: rocksdb-query -version: 0.1.4 +version: 0.2.0 synopsis: RocksDB database querying library for Haskell description: Please see the README on GitHub at category: Database @@ -52,6 +52,7 @@ build-depends: base >=4.7 && <5 , cereal + , data-default , hspec , rocksdb-haskell , rocksdb-query diff --git a/src/Database/RocksDB/Query.hs b/src/Database/RocksDB/Query.hs --- a/src/Database/RocksDB/Query.hs +++ b/src/Database/RocksDB/Query.hs @@ -1,25 +1,37 @@ {-# LANGUAGE LambdaCase #-} {-# LANGUAGE MultiParamTypeClasses #-} +{-| +Module : Database.RocksDB.Query +Copyright : No rights reserved +License : UNLICENSE +Maintainer : xenog@protonmail.com +Stability : experimental +Portability : POSIX + +Query functions to make interaction with RocksDB stores easier and safer. +-} module Database.RocksDB.Query where -import qualified Data.ByteString as B import Conduit -import Data.Serialize as S -import Database.RocksDB as R +import qualified Data.ByteString as B +import Data.Serialize as S +import Database.RocksDB as R import UnliftIO +-- | Class for types that are database keys. class Key key + +-- | Class for types that are corresponding database key and value. class KeyValue key value -- | Read a value from the database, or 'Nothing' if not found. retrieve :: (MonadIO m, KeyValue key value, Serialize key, Serialize value) => DB - -> Maybe Snapshot + -> ReadOptions -> key -> m (Maybe value) -retrieve db snapshot key = do - let opts = defaultReadOptions {useSnapshot = snapshot} +retrieve db opts key = R.get db opts (encode key) >>= \case Nothing -> return Nothing Just bytes -> @@ -27,6 +39,7 @@ Left e -> throwString e Right x -> return (Just x) +-- | Internal function for recursively matching a key. matchRecursive :: ( MonadIO m , KeyValue key value @@ -66,7 +79,7 @@ -- > db <- open "test-db" defaultOptions {createIfMissing = True} -- > insert db (FullKey "hello" "world") "despite all my rage" -- > Just record <- runResourceT . runConduit $ --- > matching db Nothing (ShortKey "hello") .| headC +-- > matching db def (ShortKey "hello") .| headC -- > print (record :: (MyKey, String)) -- > -- (Fullkey "hello" "world","despite all my rage") -- @@ -81,11 +94,10 @@ , Serialize value ) => DB - -> Maybe Snapshot + -> ReadOptions -> key -> ConduitT () (key, value) m () -matching db snapshot base = do - let opts = defaultReadOptions {useSnapshot = snapshot} +matching db opts base = withIterator db opts $ \it -> do iterSeek it (encode base) matchRecursive base it @@ -99,12 +111,11 @@ , Serialize value ) => DB - -> Maybe Snapshot + -> ReadOptions -> key -> key -> ConduitT () (key, value) m () -matchingSkip db snapshot base start = do - let opts = defaultReadOptions {useSnapshot = snapshot} +matchingSkip db opts base start = withIterator db opts $ \it -> do iterSeek it (encode start) matchRecursive base it @@ -146,11 +157,11 @@ , Serialize value ) => DB - -> Maybe Snapshot + -> ReadOptions -> key -> m (Maybe (key, value)) -firstMatching db snapshot base = - runResourceT . runConduit $ matching db snapshot base .| headC +firstMatching db opts base = + runResourceT . runConduit $ matching db opts base .| headC -- | Like 'matchingSkip', but return the first element only. firstMatchingSkip :: @@ -160,13 +171,13 @@ , Serialize value ) => DB - -> Maybe Snapshot + -> ReadOptions -> key -> key -> m (Maybe (key, value)) -firstMatchingSkip db snapshot base start = +firstMatchingSkip db opts base start = runResourceT . runConduit $ - matchingSkip db snapshot base start .| headC + matchingSkip db opts base start .| headC -- | Like 'matching' but return a list. matchingAsList :: @@ -176,12 +187,12 @@ , Serialize value ) => DB - -> Maybe Snapshot + -> ReadOptions -> key -> m [(key, value)] -matchingAsList db snapshot base = +matchingAsList db opts base = runResourceT . runConduit $ - matching db snapshot base .| sinkList + matching db opts base .| sinkList -- | Like 'matchingSkip', but return a list. matchingSkipAsList :: @@ -191,10 +202,10 @@ , Serialize value ) => DB - -> Maybe Snapshot + -> ReadOptions -> key -> key -> m [(key, value)] -matchingSkipAsList db snapshot base start = +matchingSkipAsList db opts base start = runResourceT . runConduit $ - matchingSkip db snapshot base start .| sinkList + matchingSkip db opts base start .| sinkList diff --git a/test/Spec.hs b/test/Spec.hs --- a/test/Spec.hs +++ b/test/Spec.hs @@ -2,6 +2,7 @@ {-# LANGUAGE MultiParamTypeClasses #-} import Control.Applicative import Control.Monad +import Data.Default import Data.Serialize as S import Data.Word import Database.RocksDB as R @@ -42,28 +43,28 @@ setup $ \db -> describe "database" $ do it "reads a record" $ do - r <- retrieve db Nothing (KeyTwo 1 2) + r <- retrieve db def (KeyTwo 1 2) r `shouldBe` Just "Hello First World Again!" it "reads two records at the end" $ do let ls = [ (KeyTwo 2 1, "Hello Second World!") , (KeyTwo 2 2, "Hello Second World Again!") ] - rs <- matchingAsList db Nothing (KeyTwoBase 2) + rs <- matchingAsList db def (KeyTwoBase 2) rs `shouldBe` ls it "reads two records in the middle" $ do let ls = [ (KeyTwo 1 1, "Hello First World!") , (KeyTwo 1 2, "Hello First World Again!") ] - rs <- matchingAsList db Nothing (KeyTwoBase 1) + rs <- matchingAsList db def (KeyTwoBase 1) rs `shouldBe` ls it "query and skip" $ do let ex = (KeyTwo 2 2, "Hello Second World Again!") rs <- matchingSkipAsList db - Nothing + def (KeyTwoBase 2) (KeyTwo 2 2) rs `shouldBe` [ex]