Database.Haskey.Store.Class

A storage back-end manages physical storage of pages.

Class

class (Applicative m, Monad m) => StoreM hnd m | m -> hnd where

A storage back-end that can store and fetch physical pages.

Minimal complete definition

openHandle, flushHandle, closeHandle, removeHandle, nodePageSize, maxPageSize, getNodePage, putNodePage, getOverflow, putOverflow, listOverflows

Methods

openHandle :: hnd -> m ()

Open a database handle for reading and writing.

flushHandle :: hnd -> m ()

Flush the contents of a handle to disk (or other storage).

closeHandle :: hnd -> m ()

Close a database handle.

removeHandle :: hnd -> m ()

Remove a handle from the storage back-end.

nodePageSize :: (Key key, Value val) => m (Height height -> Node height key val -> PageSize)

A function that calculates the hypothetical size of a node, if it were to be written to a page (regardless of the maximum page size).

maxPageSize :: m PageSize

The maximum page size the allocator can handle.

maxKeySize :: m Word64

Get the maximum key size

The default implementation will repeatedly call calculateMaxKeySize. You might want to cache this value in your own implementation.

maxValueSize :: m Word64

Get the maximum value size

The default implementation will repeatedly call calculateMaxValueSize. You might want to cache this value in your own implementation.

getNodePage :: (Key key, Value val) => hnd -> Height height -> Proxy key -> Proxy val -> NodeId height key val -> m (Node height key val)

Read a page and return the actual node and the transaction id when the node was written.

putNodePage :: (Key key, Value val) => hnd -> Height height -> NodeId height key val -> Node height key val -> m ()

Write a node to a physical page.

getOverflow :: Value val => hnd -> Proxy val -> m val

Read a value from an overflow page

putOverflow :: Value val => hnd -> val -> m ()

Write a value to an overflow page

listOverflows :: hnd -> m [hnd]

List overflow pages in the specific overflow directory.

The result should include **AT LEAST** the handles in the specified directory, but it may contain more handles, even handles that do not belong to an overflow page.

Instances

StoreM hnd m => StoreM hnd (StateT s m)

Methods

openHandle :: hnd -> StateT s m ()

flushHandle :: hnd -> StateT s m ()

closeHandle :: hnd -> StateT s m ()

removeHandle :: hnd -> StateT s m ()

nodePageSize :: (Key key, Value val) => StateT s m (Height height -> Node height key val -> PageSize)

maxPageSize :: StateT s m PageSize

maxKeySize :: StateT s m Word64

maxValueSize :: StateT s m Word64

getNodePage :: (Key key, Value val) => hnd -> Height height -> Proxy * key -> Proxy * val -> NodeId height key val -> StateT s m (Node height key val)

putNodePage :: (Key key, Value val) => hnd -> Height height -> NodeId height key val -> Node height key val -> StateT s m ()

getOverflow :: Value val => hnd -> Proxy * val -> StateT s m val

putOverflow :: Value val => hnd -> val -> StateT s m ()

listOverflows :: hnd -> StateT s m [hnd]

(Applicative m, Monad m, MonadIO m, MonadThrow m, Ord fp, Show fp, Typeable * fp) => StoreM fp (MemoryStoreT fp m)

Methods

openHandle :: fp -> MemoryStoreT fp m ()

flushHandle :: fp -> MemoryStoreT fp m ()

closeHandle :: fp -> MemoryStoreT fp m ()

removeHandle :: fp -> MemoryStoreT fp m ()

nodePageSize :: (Key key, Value val) => MemoryStoreT fp m (Height height -> Node height key val -> PageSize)

maxPageSize :: MemoryStoreT fp m PageSize

maxKeySize :: MemoryStoreT fp m Word64

maxValueSize :: MemoryStoreT fp m Word64

getNodePage :: (Key key, Value val) => fp -> Height height -> Proxy * key -> Proxy * val -> NodeId height key val -> MemoryStoreT fp m (Node height key val)

putNodePage :: (Key key, Value val) => fp -> Height height -> NodeId height key val -> Node height key val -> MemoryStoreT fp m ()

getOverflow :: Value val => fp -> Proxy * val -> MemoryStoreT fp m val

putOverflow :: Value val => fp -> val -> MemoryStoreT fp m ()

listOverflows :: fp -> MemoryStoreT fp m [fp]

(Applicative m, Monad m, MonadIO m, MonadThrow m) => StoreM FilePath (FileStoreT FilePath m)

Methods

openHandle :: FilePath -> FileStoreT FilePath m ()

flushHandle :: FilePath -> FileStoreT FilePath m ()

closeHandle :: FilePath -> FileStoreT FilePath m ()

removeHandle :: FilePath -> FileStoreT FilePath m ()

nodePageSize :: (Key key, Value val) => FileStoreT FilePath m (Height height -> Node height key val -> PageSize)

maxPageSize :: FileStoreT FilePath m PageSize

maxKeySize :: FileStoreT FilePath m Word64

maxValueSize :: FileStoreT FilePath m Word64

getNodePage :: (Key key, Value val) => FilePath -> Height height -> Proxy * key -> Proxy * val -> NodeId height key val -> FileStoreT FilePath m (Node height key val)

putNodePage :: (Key key, Value val) => FilePath -> Height height -> NodeId height key val -> Node height key val -> FileStoreT FilePath m ()

getOverflow :: Value val => FilePath -> Proxy * val -> FileStoreT FilePath m val

putOverflow :: Value val => FilePath -> val -> FileStoreT FilePath m ()

listOverflows :: FilePath -> FileStoreT FilePath m [FilePath]

StoreM hnd m => StoreM hnd (ReaderT * s m)

Methods

openHandle :: hnd -> ReaderT * s m ()

flushHandle :: hnd -> ReaderT * s m ()

closeHandle :: hnd -> ReaderT * s m ()

removeHandle :: hnd -> ReaderT * s m ()

nodePageSize :: (Key key, Value val) => ReaderT * s m (Height height -> Node height key val -> PageSize)

maxPageSize :: ReaderT * s m PageSize

maxKeySize :: ReaderT * s m Word64

maxValueSize :: ReaderT * s m Word64

getNodePage :: (Key key, Value val) => hnd -> Height height -> Proxy * key -> Proxy * val -> NodeId height key val -> ReaderT * s m (Node height key val)

putNodePage :: (Key key, Value val) => hnd -> Height height -> NodeId height key val -> Node height key val -> ReaderT * s m ()

getOverflow :: Value val => hnd -> Proxy * val -> ReaderT * s m val

putOverflow :: Value val => hnd -> val -> ReaderT * s m ()

listOverflows :: hnd -> ReaderT * s m [hnd]

Helpers

arbitrarySearch :: (Ord v, Integral n) => n -> (n -> v) -> v -> n

Search an arbitrary number, less than a limit, greater than a starting value.

calculateMaxKeySize

Arguments

:: PageSize

Maximum pages size

-> (Node Z ZeroEncoded ZeroEncoded -> PageSize)

Function that calculates the page size of a node

-> Word64

Maximum key size

Calculate the maximum key size.

Return the size for which at least 4 key-value pairs with keys and values of that size can fit in a leaf node.

calculateMaxValueSize

Arguments

:: PageSize

Maximum page size

-> Word64

Maximum key size

-> (Node Z ZeroEncoded ZeroEncoded -> PageSize)

Function that calculates the page size of a node

-> Word64

Maximum value size

Calculate the maximum value size.

Return the size for which at least 4 key-value pairs of the specified maximum key size and values of the returned size can fit in a leaf node. that size can fit in a leaf node.

data ZeroEncoded

Data type which encodes the integer using a variable amount of NULL or ONE bytes.

Constructors

ZeroEncoded

Fields

• getZeroEncoded :: Word64
• getZeroEncodedValue :: Word64

Instances

Eq ZeroEncoded

Methods

(==) :: ZeroEncoded -> ZeroEncoded -> Bool

(/=) :: ZeroEncoded -> ZeroEncoded -> Bool

Ord ZeroEncoded

Methods

compare :: ZeroEncoded -> ZeroEncoded -> Ordering

(<) :: ZeroEncoded -> ZeroEncoded -> Bool

(<=) :: ZeroEncoded -> ZeroEncoded -> Bool

(>) :: ZeroEncoded -> ZeroEncoded -> Bool

(>=) :: ZeroEncoded -> ZeroEncoded -> Bool

max :: ZeroEncoded -> ZeroEncoded -> ZeroEncoded

min :: ZeroEncoded -> ZeroEncoded -> ZeroEncoded

Show ZeroEncoded

Methods

showsPrec :: Int -> ZeroEncoded -> ShowS

show :: ZeroEncoded -> String

showList :: [ZeroEncoded] -> ShowS

Binary ZeroEncoded

Methods

put :: ZeroEncoded -> Put

get :: Get ZeroEncoded

putList :: [ZeroEncoded] -> Put

Key ZeroEncoded

Methods

narrow :: ZeroEncoded -> ZeroEncoded -> (ZeroEncoded, ZeroEncoded)

Value ZeroEncoded

Methods

fixedSize :: Proxy * ZeroEncoded -> Maybe Int