Database.LevelDB.Streaming

High-level, Data.List-like, streaming interface to Database.LevelDB.Iterator.

This module contains types and functions to construct Streams from Iterators, and re-exports the functions operating on Streams from Data.Stream.Monadic.

Note that most of the functions from the latter module are (intentionally) conflicting with the Prelude, it is thus recommended to import this module qualified:

import Database.LevelDB -- or Database.LevelDB.Base
import qualified Database.LevelDB.Streaming as S

Documentation

data Slice

Constructors

Slice !Iterator (Maybe KeyRange) !Direction

data KeyRange

Constructors

KeyRange

Fields

start :: !ByteString

end :: ByteString -> Ordering

AllKeys

data Direction

Constructors

Asc

Desc

Instances

Show Direction

type Key = ByteString

type Value = ByteString

type Entry = (Key, Value)

Constructing streams

keySlice :: (Applicative m, MonadIO m) => Iterator -> KeyRange -> Direction -> Stream m Key

Create a Stream which yields only the keys of the given KeyRange (in the given Direction).

Since traversing the Stream mutates the state of the underlying Iterator, it is obviously unsafe to share the latter (between threads, or when zipping). Hence, it is highly recommended to create a new Iterator for each Stream.

entrySlice :: (Applicative m, MonadIO m) => Iterator -> KeyRange -> Direction -> Stream m Entry

Create a Stream which yields key/value pairs of the given KeyRange (in the given Direction).

Since traversing the Stream mutates the state of the underlying Iterator, it is obviously unsafe to share the latter (between threads, or when zipping). Hence, it is highly recommended to create a new Iterator for each Stream.

Re-exports

module Data.Stream.Monadic