Safe Haskell	None
Language	Haskell2010

Database.Haskey.Store.File

Contents

Storage
Binary encoding
Exceptions

Description

On-disk storage back-end. Can be used as a storage back-end for the append-only page allocator (see Data.BTree.Alloc).

Synopsis

Storage

data Page (t :: PageType) where Source #

A decoded page, of a certain type t of kind PageType.

Constructors

EmptyPage :: Page TypeEmpty
ConcurrentMetaPage :: Root root => ConcurrentMeta root -> Page TypeConcurrentMeta
OverflowPage :: Value v => v -> Page TypeOverflow
LeafNodePage :: (Key k, Value v) => Height Z -> Node Z k v -> Page TypeLeafNode
IndexNodePage :: (Key k, Value v) => Height (S h) -> Node (S h) k v -> Page TypeIndexNode

data FileStoreConfig Source #

File store configuration.

The default configuration can be obtained by using defFileStoreConfig

A configuration with a specific page size can be obtained by using fileStoreConfigWithPageSize.

Constructors

FileStoreConfig
Fields fileStoreConfigPageSize :: !PageSize fileStoreConfigMaxKeySize :: !Word64 fileStoreConfigMaxValueSize :: !Word64

Instances

Show FileStoreConfig Source #
Methods showsPrec :: Int -> FileStoreConfig -> ShowS # show :: FileStoreConfig -> String # showList :: [FileStoreConfig] -> ShowS #
Monad m => MonadReader FileStoreConfig (FileStoreT fp m) Source #
Methods ask :: FileStoreT fp m FileStoreConfig # local :: (FileStoreConfig -> FileStoreConfig) -> FileStoreT fp m a -> FileStoreT fp m a # reader :: (FileStoreConfig -> a) -> FileStoreT fp m a #

defFileStoreConfig :: FileStoreConfig Source #

The default configuration

This is an unwrapped fileStoreConfigWithPageSize with a page size of 4096 bytes.

fileStoreConfigWithPageSize :: PageSize -> Maybe FileStoreConfig Source #

Create a configuration with a specific page size.

The maximum key and value sizes are calculated using calculateMaxKeySize and calculateMaxValueSize.

If the page size is too small, Nothing is returned.

data FileStoreT fp m a Source #

Monad in which on-disk storage operations can take place.

Two important instances are StoreM making it a storage back-end, and ConcurrentMetaStoreM making it a storage back-end compatible with the concurrent page allocator.

Instances

Monad m => MonadReader FileStoreConfig (FileStoreT fp m) Source #
Methods ask :: FileStoreT fp m FileStoreConfig # local :: (FileStoreConfig -> FileStoreConfig) -> FileStoreT fp m a -> FileStoreT fp m a # reader :: (FileStoreConfig -> a) -> FileStoreT fp m a #
(Applicative m, Monad m, MonadIO m, MonadThrow m) => StoreM FilePath (FileStoreT FilePath m) Source #
Methods openHandle :: FilePath -> FileStoreT FilePath m () Source # lockHandle :: FilePath -> FileStoreT FilePath m () Source # releaseHandle :: FilePath -> FileStoreT FilePath m () Source # flushHandle :: FilePath -> FileStoreT FilePath m () Source # closeHandle :: FilePath -> FileStoreT FilePath m () Source # removeHandle :: FilePath -> FileStoreT FilePath m () Source # nodePageSize :: (Key key, Value val) => FileStoreT FilePath m (Height height -> Node height key val -> PageSize) Source # maxPageSize :: FileStoreT FilePath m PageSize Source # maxKeySize :: FileStoreT FilePath m Word64 Source # maxValueSize :: FileStoreT FilePath m Word64 Source # getNodePage :: (Key key, Value val) => FilePath -> Height height -> Proxy * key -> Proxy * val -> NodeId height key val -> FileStoreT FilePath m (Node height key val) Source # putNodePage :: (Key key, Value val) => FilePath -> Height height -> NodeId height key val -> Node height key val -> FileStoreT FilePath m () Source # getOverflow :: Value val => FilePath -> Proxy * val -> FileStoreT FilePath m val Source # putOverflow :: Value val => FilePath -> val -> FileStoreT FilePath m () Source # listOverflows :: FilePath -> FileStoreT FilePath m [FilePath] Source #
Monad m => Monad (FileStoreT fp m) Source #
Methods (>>=) :: FileStoreT fp m a -> (a -> FileStoreT fp m b) -> FileStoreT fp m b # (>>) :: FileStoreT fp m a -> FileStoreT fp m b -> FileStoreT fp m b # return :: a -> FileStoreT fp m a # fail :: String -> FileStoreT fp m a #
Functor m => Functor (FileStoreT fp m) Source #
Methods fmap :: (a -> b) -> FileStoreT fp m a -> FileStoreT fp m b # (<$) :: a -> FileStoreT fp m b -> FileStoreT fp m a #
Monad m => Applicative (FileStoreT fp m) Source #
Methods pure :: a -> FileStoreT fp m a # (<>) :: FileStoreT fp m (a -> b) -> FileStoreT fp m a -> FileStoreT fp m b # liftA2 :: (a -> b -> c) -> FileStoreT fp m a -> FileStoreT fp m b -> FileStoreT fp m c # (>) :: FileStoreT fp m a -> FileStoreT fp m b -> FileStoreT fp m b # (<*) :: FileStoreT fp m a -> FileStoreT fp m b -> FileStoreT fp m a #
MonadIO m => MonadIO (FileStoreT fp m) Source #
Methods liftIO :: IO a -> FileStoreT fp m a #
MonadThrow m => MonadThrow (FileStoreT fp m) Source #
Methods throwM :: Exception e => e -> FileStoreT fp m a #
MonadCatch m => MonadCatch (FileStoreT fp m) Source #
Methods catch :: Exception e => FileStoreT fp m a -> (e -> FileStoreT fp m a) -> FileStoreT fp m a #
MonadMask m => MonadMask (FileStoreT fp m) Source #
Methods mask :: ((forall a. FileStoreT fp m a -> FileStoreT fp m a) -> FileStoreT fp m b) -> FileStoreT fp m b # uninterruptibleMask :: ((forall a. FileStoreT fp m a -> FileStoreT fp m a) -> FileStoreT fp m b) -> FileStoreT fp m b # generalBracket :: FileStoreT fp m a -> (a -> ExitCase b -> FileStoreT fp m c) -> (a -> FileStoreT fp m b) -> FileStoreT fp m (b, c) #
(Applicative m, Monad m, MonadIO m, MonadCatch m) => ConcurrentMetaStoreM (FileStoreT FilePath m) Source #
Methods putConcurrentMeta :: Root root => FilePath -> ConcurrentMeta root -> FileStoreT FilePath m () Source # readConcurrentMeta :: Root root => FilePath -> Proxy * root -> FileStoreT FilePath m (Maybe (ConcurrentMeta root)) Source #

runFileStoreT Source #

Arguments

:: Monad m
=> FileStoreT FilePath m a	Action
-> FileStoreConfig	Configuration
-> m a

Run the storage operations in the FileStoreT monad, given a collection of open files.

Binary encoding

encodeAndPad :: PageSize -> Page t -> Maybe ByteString Source #

Encode a page padding it to the maxim page size.

Return Nothing of the page is too large to fit into one page size.

Exceptions

newtype FileNotFoundError hnd Source #

Exception thrown when a file is accessed that doesn't exist.

Constructors

FileNotFoundError hnd

Instances

Show hnd => Show (FileNotFoundError hnd) Source #
Methods showsPrec :: Int -> FileNotFoundError hnd -> ShowS # show :: FileNotFoundError hnd -> String # showList :: [FileNotFoundError hnd] -> ShowS #
(Typeable * hnd, Show hnd) => Exception (FileNotFoundError hnd) Source #
Methods toException :: FileNotFoundError hnd -> SomeException # fromException :: SomeException -> Maybe (FileNotFoundError hnd) # displayException :: FileNotFoundError hnd -> String #

data PageOverflowError Source #

Exception thrown when a page that is too large is written.

As used in putNodePage.

Constructors

PageOverflowError

Instances

Show PageOverflowError Source #
Methods showsPrec :: Int -> PageOverflowError -> ShowS # show :: PageOverflowError -> String # showList :: [PageOverflowError] -> ShowS #
Exception PageOverflowError Source #
Methods toException :: PageOverflowError -> SomeException # fromException :: SomeException -> Maybe PageOverflowError # displayException :: PageOverflowError -> String #

data WrongNodeTypeError Source #

Exception thrown when a node cannot be cast to the right type.

As used in getNodePage.

Constructors

WrongNodeTypeError

Instances

Show WrongNodeTypeError Source #
Methods showsPrec :: Int -> WrongNodeTypeError -> ShowS # show :: WrongNodeTypeError -> String # showList :: [WrongNodeTypeError] -> ShowS #
Exception WrongNodeTypeError Source #
Methods toException :: WrongNodeTypeError -> SomeException # fromException :: SomeException -> Maybe WrongNodeTypeError # displayException :: WrongNodeTypeError -> String #

data WrongOverflowValueError Source #

Exception thrown when a value from an overflow page cannot be cast.

As used in getOverflow.

Constructors

WrongOverflowValueError

Instances

Show WrongOverflowValueError Source #
Methods showsPrec :: Int -> WrongOverflowValueError -> ShowS # show :: WrongOverflowValueError -> String # showList :: [WrongOverflowValueError] -> ShowS #
Exception WrongOverflowValueError Source #
Methods toException :: WrongOverflowValueError -> SomeException # fromException :: SomeException -> Maybe WrongOverflowValueError # displayException :: WrongOverflowValueError -> String #