License	Apache 2.0
Maintainer	smokejumperit@gmail.com
Stability	experimental
Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Snowchecked

Description

This generates unique (guaranteed) identifiers build from a timestamp, counter, and node id. Identifiers are convertible to values which are monotonically increasing with respect to time.

Synopsis

newSnowcheckedGen :: MonadIO io => SnowcheckedConfig -> Word256 -> io SnowcheckedGen
nextFlake :: MonadIO io => SnowcheckedGen -> io Flake
data SnowcheckedConfig = SnowcheckedConfig {
- confTimeBits :: Word8
- confCountBits :: Word8
- confNodeBits :: Word8
- confCheckBits :: Word8
}
data SnowcheckedGen
data Flake
snowcheckedConfigBitCount :: SnowcheckedConfig -> Word32
uniqueFlakeCount :: SnowcheckedConfig -> Integer

Documentation

newSnowcheckedGen :: MonadIO io => SnowcheckedConfig -> Word256 -> io SnowcheckedGen Source #

Create a new generator. Takes a configuration and node id. The node id may be any value that fits in a Word256, but it will be truncated to the number of bits specified in the provided configuration.

nextFlake :: MonadIO io => SnowcheckedGen -> io Flake Source #

Generates the next id.

data SnowcheckedConfig Source #

Configuration that specifies how many bits are used for each part of the id. These values are not validated and may be any legal value for the type.

The default value provided by def is 64 bits in total length, just like the original Snowflake algorithm.

Note that specifying 0 check bits results in the normal Snowflake generation. Setting confTimeBits or confCountBits near zero will significantly limit the total number of UIDs that can be generated, as well as the throughput of the UID generation.

Constructors

SnowcheckedConfig
Fields confTimeBits :: Word8 Number of bits used to hold the time confCountBits :: Word8 Number of bits used to count instances per-time confNodeBits :: Word8 Number of bits derived from the node id confCheckBits :: Word8 Number of bits used to store the checksum

Instances

Instances details

Generic SnowcheckedConfig Source #
Instance details Defined in Data.Snowchecked.Types Associated Types type Rep SnowcheckedConfig :: Type -> Type # Methods from :: SnowcheckedConfig -> Rep SnowcheckedConfig x # to :: Rep SnowcheckedConfig x -> SnowcheckedConfig #
Show SnowcheckedConfig Source #
Instance details Defined in Data.Snowchecked.Types Methods showsPrec :: Int -> SnowcheckedConfig -> ShowS # show :: SnowcheckedConfig -> String # showList :: [SnowcheckedConfig] -> ShowS #
Default SnowcheckedConfig Source #
Instance details Defined in Data.Snowchecked.Types Methods def :: SnowcheckedConfig #
NFData SnowcheckedConfig Source #
Instance details Defined in Data.Snowchecked.Types Methods rnf :: SnowcheckedConfig -> () #
Eq SnowcheckedConfig Source #
Instance details Defined in Data.Snowchecked.Types Methods (==) :: SnowcheckedConfig -> SnowcheckedConfig -> Bool # (/=) :: SnowcheckedConfig -> SnowcheckedConfig -> Bool #
Ord SnowcheckedConfig Source #
Instance details Defined in Data.Snowchecked.Types Methods compare :: SnowcheckedConfig -> SnowcheckedConfig -> Ordering # (<) :: SnowcheckedConfig -> SnowcheckedConfig -> Bool # (<=) :: SnowcheckedConfig -> SnowcheckedConfig -> Bool # (>) :: SnowcheckedConfig -> SnowcheckedConfig -> Bool # (>=) :: SnowcheckedConfig -> SnowcheckedConfig -> Bool # max :: SnowcheckedConfig -> SnowcheckedConfig -> SnowcheckedConfig # min :: SnowcheckedConfig -> SnowcheckedConfig -> SnowcheckedConfig #
type Rep SnowcheckedConfig Source #
Instance details Defined in Data.Snowchecked.Types type Rep SnowcheckedConfig = D1 ('MetaData "SnowcheckedConfig" "Data.Snowchecked.Types" "snowchecked-0.0.2.0-JwkIfxT25kc6AQyhojYiCd" 'False) (C1 ('MetaCons "SnowcheckedConfig" 'PrefixI 'True) ((S1 ('MetaSel ('Just "confTimeBits") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Word8) :: S1 ('MetaSel ('Just "confCountBits") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Word8)) :: (S1 ('MetaSel ('Just "confNodeBits") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Word8) :*: S1 ('MetaSel ('Just "confCheckBits") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Word8))))

data SnowcheckedGen Source #

The state that needs to be communicated between flake generation calls. This should be treated as opaque by consumers of this library: messing about with its internals may cause your code to hang indefinitely.

data Flake Source #

The state of a given generated instance. Note that the actual value is calculated on demand.

Instances

Instances details

Generic Flake Source #
Instance details Defined in Data.Snowchecked.Types Associated Types type Rep Flake :: Type -> Type # Methods from :: Flake -> Rep Flake x # to :: Rep Flake x -> Flake #
Show Flake Source #
Instance details Defined in Data.Snowchecked.Types Methods showsPrec :: Int -> Flake -> ShowS # show :: Flake -> String # showList :: [Flake] -> ShowS #
NFData Flake Source #
Instance details Defined in Data.Snowchecked.Types Methods rnf :: Flake -> () #
Eq Flake Source #
Instance details Defined in Data.Snowchecked.Types Methods (==) :: Flake -> Flake -> Bool # (/=) :: Flake -> Flake -> Bool #
Ord Flake Source #
Instance details Defined in Data.Snowchecked.Types Methods compare :: Flake -> Flake -> Ordering # (<) :: Flake -> Flake -> Bool # (<=) :: Flake -> Flake -> Bool # (>) :: Flake -> Flake -> Bool # (>=) :: Flake -> Flake -> Bool # max :: Flake -> Flake -> Flake # min :: Flake -> Flake -> Flake #
type Rep Flake Source #
Instance details Defined in Data.Snowchecked.Types type Rep Flake = D1 ('MetaData "Flake" "Data.Snowchecked.Types" "snowchecked-0.0.2.0-JwkIfxT25kc6AQyhojYiCd" 'False) (C1 ('MetaCons "Flake" 'PrefixI 'True) ((S1 ('MetaSel ('Just "flakeTime") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Word256) :: S1 ('MetaSel ('Just "flakeCount") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Word256)) :: (S1 ('MetaSel ('Just "flakeNodeId") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Word256) :*: S1 ('MetaSel ('Just "flakeConfig") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 SnowcheckedConfig))))

snowcheckedConfigBitCount :: SnowcheckedConfig -> Word32 Source #

Calculates the number of bits in each Flake generated using a given configuration. It returns a Word32 because there are 4 fields and the bitlength of each field fits in a Word8, so the total bit count must fit within a Word32.

uniqueFlakeCount :: SnowcheckedConfig -> Integer Source #

Provides the count of total number of unique flakes possibly generated by a node using this configuration.