Data.ZoomCache.Codec

This module re-exports the required interfaces and some useful functions for developing zoom-cache codecs.

To implement a codec, specify SummaryData and SummaryWork types, and implement the methods of the ZoomReadable and ZoomWritable classes.

For sample implementations, read the source of the provided instances Data.ZoomCache.Int and Data.ZoomCache.Double.

Required interfaces

class ZoomReadable a where

A codec instance must specify a SummaryData type, and implement all methods of this class.

Associated Types

data SummaryData a :: *

Summaries of a subsequence of values of type a. In the default instances for Int and Double, this is a record containing values such as the maximum, minimum and mean of the subsequence.

Methods

readRaw :: (Functor m, MonadIO m) => Iteratee [Word8] m a

An iteratee to read one value of type a from a stream of '[Word8]'.

readSummary :: (Functor m, MonadIO m) => Iteratee [Word8] m (SummaryData a)

An iteratee to read one value of type 'SummaryData a' from a stream of '[Word8]'.

prettyRaw :: a -> String

Pretty printing, used for dumping values of type a.

prettySummaryData :: SummaryData a -> String

Pretty printing for values of type 'SummaryData a'.

Instances

ZoomReadable Double

ZoomReadable Int

class ZoomWritable a where

A codec instance must additionally specify a SummaryWork type

Associated Types

data SummaryWork a :: *

Intermediate calculations

Methods

fromRaw :: a -> Builder

Serialize a value of type a

fromSummaryData :: SummaryData a -> Builder

Serialize a 'SummaryData a'

initSummaryWork :: TimeStamp -> SummaryWork a

Generate a new 'SummaryWork a', given an initial timestamp.

updateSummaryData :: Int -> TimeStamp -> a -> SummaryWork a -> SummaryWork a

Update a SummaryData with the value of a occuring at the given TimeStamp.

toSummaryData :: Double -> SummaryWork a -> SummaryData a

Finalize a 'SummaryWork a', generating a 'SummaryData a'.

appendSummaryData :: Double -> SummaryData a -> Double -> SummaryData a -> SummaryData a

Append two SummaryData

Instances

ZoomWritable Double

ZoomWritable Int

class ZoomWrite t where

The ZoomWrite class provides write, a method to write a Haskell value to an open ZoomCache file.

Methods

write :: TrackNo -> t -> ZoomW ()

Write a value to an open ZoomCache file.

Instances

ZoomWrite Double

ZoomWrite Int

ZoomWrite (TimeStamp, Double)

ZoomWrite (TimeStamp, Int)

Raw data reading iteratees

readInt16be :: (Functor m, MonadIO m) => Iteratee [Word8] m Int

Read 2 bytes as a big-endian Int.

readInt32be :: (Functor m, MonadIO m) => Iteratee [Word8] m Int

Read 4 bytes as a big-endian Int.

readInt64be :: (Functor m, MonadIO m, Integral a) => Iteratee [Word8] m a

Read 8 bytes as a big-endian Integer

readDouble64be :: (Functor m, MonadIO m) => Iteratee [Word8] m Double

Read 8 bytes as a big-endian Double

readRational64be :: (Functor m, MonadIO m) => Iteratee [Word8] m Rational

Read 16 bytes as a big-endian Rational, encoded as an 8 byte big endian numerator followed by an 8 byte big endian denominator.

ZoomWrite instance helpers

writeData :: (Typeable a, ZoomWrite a, ZoomWritable a) => TrackNo -> a -> ZoomW ()

writeDataVBR :: (Typeable a, ZoomWrite a, ZoomWritable a) => TrackNo -> (TimeStamp, a) -> ZoomW ()

Builders

fromRational64 :: Rational -> Builder

Serialize a Rational as a sequence of two 64bit big endian format integers.

fromIntegral32be :: forall a. Integral a => a -> Builder

Serialize an Integral in 32bit big endian format.

fromDouble :: Double -> Builder

Serialize a Double in big-endian IEEE 754-2008 binary64 format (IEEE 754-1985 double format).

ZoomCache Types

data TimeStamp

Constructors

TS

Fields

unTS :: !Int64

Instances

Eq TimeStamp

Ord TimeStamp

Show TimeStamp

ZoomWrite (TimeStamp, Double)

ZoomWrite (TimeStamp, Int)