Copyright	Copyright © 2019 Lars Kuhtz <lakuhtz@gmail.com>
License	BSD3
Maintainer	Lars Kuhtz <lakuhtz@gmail.com>
Stability	experimental
Safe Haskell	None
Language	Haskell2010

Data.Cuckoo.Internal

Contents

Hash functions

Description

Internal Utilities. No guarantee is made about the stability of these functions. Changes to these function won't be announced in the CHANGELOG and are not reflected in the package version.

Synopsis

w :: forall (n :: Nat). KnownNat n => Int
int :: Integral a => Num b => a -> b
fit :: Real a => Real b => Integral c => a -> b -> c
intFit :: Integral a => Integral b => a -> b -> a
nextPowerOfTwo :: Real a => Integral b => a -> b
intNextPowerOfTwo :: Int -> Int
set :: PrimMonad m => MutableByteArray (PrimState m) -> Int -> Word64 -> m ()
get :: PrimMonad m => MutableByteArray (PrimState m) -> Int -> m Word64
sip :: Storable a => Int -> a -> Word64
fnv1a :: Storable a => Int -> a -> Word64
fnv1a_bytes :: ByteArrayAccess a => Int -> a -> Word64
sip_bytes :: ByteArrayAccess a => Int -> a -> Word64
sip2 :: Storable a => Int -> a -> Word64

Documentation

w :: forall (n :: Nat). KnownNat n => Int Source #

Reify type level Nat into Int value.

int :: Integral a => Num b => a -> b Source #

An shorter alias for fromIntegral.

fit :: Real a => Real b => Integral c => a -> b -> c Source #

fit a b computes how many bs are needed to fit a, i.e. \(\left\lceil\frac{a}{b}\right\rceil\).

For instance,

fit 7 3 == 3

fit 6 3 == 2

intFit :: Integral a => Integral b => a -> b -> a Source #

fit a b computes how many bs are needed to fit a, i.e. \(\left\lceil\frac{a}{b}\right\rceil\).

For instance,

fit 7 3 == 3

fit 6 3 == 2

nextPowerOfTwo :: Real a => Integral b => a -> b Source #

nextPowerOfTwo a computes the smallest power of two that is larger or equal than a.

intNextPowerOfTwo :: Int -> Int Source #

nextPowerOfTwo a computes the smallest power of two that is larger or equal than a.

set Source #

Arguments

:: PrimMonad m
=> MutableByteArray (PrimState m)
-> Int	index in terms of `Word32`
-> Word64	`Word64` value that is written
-> m ()

Write a Word64 value into a Word32 aligned MutableByteArray

get Source #

Arguments

:: PrimMonad m
=> MutableByteArray (PrimState m)	byte array
-> Int	index in terms of `Word32`
-> m Word64	Word64 value that contains the result bits

Get a Word64 from a Word32 aligned MutableByteArray.

Hash functions

sip Source #

Arguments

:: Storable a
=> Int	Salt
-> a	Value that is hashes
-> Word64

Computes a Sip hash for a value that has an Storable instance.

The first argument is a salt value that is used to derive the key for the hash computation.

fnv1a Source #

Arguments

:: Storable a
=> Int	Salt
-> a	Value that is hashes
-> Word64

Computes a 64 bit Fnv1a hash for a value that has an Storable instance.

The first argument is use as a salt.

fnv1a_bytes Source #

Arguments

:: ByteArrayAccess a
=> Int	Salt
-> a	Value that is hashes
-> Word64

Computes a 64 bit Fnv1a hash for a value that is an instance of ByteArrayAccess.

The first argument is use as a salt.

sip_bytes Source #

Arguments

:: ByteArrayAccess a
=> Int	Salt
-> a	Value that is hashes
-> Word64

Computes a Sip hash for a value that is an instance of ByteArrayAccess.

The first argument is a salt value that is used to derive the key for the hash computation.

sip2 :: Storable a => Int -> a -> Word64 Source #

An version of a Sip hash that is used internally. In order to avoid dependencies between different hash computations, it shouldn't be used in the implementation of instances of CuckooFilterHash.