Chan.KickChan

Kick Channels

data KickChan v a

A Channel that drops elements from the end when a KCReader lags too far behind the writer.

Creation

newKickChan :: (MVector v' a, v ~ v' RealWorld) => Int -> IO (KickChan v a)

Create a new KickChan of the requested size. The actual size will be rounded up to the next highest power of 2. The stored size will have one subtracted, because that's the value we use for masking, which is the most common operation.

kcSize :: KickChan v a -> Int

Get the size of a KickChan.

Writing

putKickChan :: (MVector v' a, v ~ v' RealWorld) => KickChan v a -> a -> IO ()

Put a value into a KickChan.

if there are multiple writers, putKickChan may block if one writer has wrapped around and a write is pending to the underlying storage location.

putKickChan will never block on readers, instead KCReaders will be invalidated if they lag too far behind.

invalidateKickChan :: KickChan v a -> IO ()

Invalidate all current readers on a channel.

Reading

data KCReader v a

A reader for a KickChan

newReader :: KickChan v a -> IO (KCReader v a)

create a new reader for a KickChan. The reader will be initialized to the head of the KickChan, so that an immediate call to readNext will block (provided no new values have been put into the chan in the meantime).

readNext :: (MVector v' a, v ~ v' RealWorld) => KCReader v a -> IO (Maybe a)

get the next value from a KCReader. This function will block if the next value is not yet available.

if Nothing is returned, the reader has lagged the writer and values have been dropped.

currentLag :: KCReader v a -> IO Int

The lag between a KCReader and its writer. Mostly useful for determining if a call to readNext will block.

type constraint helpers

type KickChanS a = KickChan (MVector RealWorld) a

type KickChanV a = KickChan (MVector RealWorld) a

type KickChanU a = KickChan (MVector RealWorld) a

kcUnboxed :: KickChan (MVector RealWorld) a -> KickChan (MVector RealWorld) a

Constrain a KickChan to work with an Unboxed data storage

kcStorable :: KickChan (MVector RealWorld) a -> KickChan (MVector RealWorld) a

Constrain a KickChan to work with a Storable data storage

kcDefault :: KickChan (MVector RealWorld) a -> KickChan (MVector RealWorld) a

Constrain a KickChan to work with a standard boxed vector data storage

type KCReaderS a = KCReader (MVector RealWorld) a

type KCReaderV a = KCReader (MVector RealWorld) a

type KCReaderU a = KCReader (MVector RealWorld) a