Safe Haskell	None
Language	GHC2024

Arbiter.Core.Codec

Contents

Column types
Row decoding
Parameter encoding
Bidirectional job write codec
Job codecs
Cron codecs
Worker codecs
Queue codecs

Description

Typed encoding and decoding for PostgreSQL queries.

RowCodec decodes result rows. It is a free applicative that each backend (postgresql-simple, hasql, orville) interprets natively.
Params is the typed parameter list for query execution.

Both use the same Col GADT.

Synopsis

data Col a where
- CInt4 :: Col Int32
- CInt8 :: Col Int64
- CText :: Col Text
- CBool :: Col Bool
- CTimestamptz :: Col UTCTime
- CJsonb :: Col Value
- CFloat8 :: Col Double
- CUuid :: Col UUID
data NullCol a where
- NotNull :: forall a. Text -> Col a -> NullCol a
- Nullable :: forall a1. Text -> Col a1 -> NullCol (Maybe a1)
type RowCodec = Ap NullCol
col :: Text -> Col a -> RowCodec a
ncol :: Text -> Col a -> RowCodec (Maybe a)
runCodec :: Applicative f => (forall x. NullCol x -> f x) -> RowCodec a -> f a
codecColumns :: RowCodec a -> [Text]
data ParamType a where
- PScalar :: forall a. Col a -> ParamType a
- PNullable :: forall a1. Col a1 -> ParamType (Maybe a1)
- PArray :: forall a1. Col a1 -> ParamType [a1]
- PNullArray :: forall a1. Col a1 -> ParamType [Maybe a1]
data SomeParam where
- SomeParam :: forall a. ParamType a -> a -> SomeParam
type Params = [SomeParam]
pval :: Col a -> a -> SomeParam
pnul :: Col a -> Maybe a -> SomeParam
parr :: Col a -> [a] -> SomeParam
pnarr :: Col a -> [Maybe a] -> SomeParam
data Codec s a
cDecode :: Codec s a -> RowCodec a
cColumns :: Codec s a -> [(Text, Text)]
cScalar :: Codec s a -> s -> Params
cArray :: Codec s a -> [s] -> Params
jobCodec :: Text -> Codec (JobWriteSource payload) (JobRead Value)
data JobWriteSource payload = JobWriteSource {
- sourceJob :: JobWrite payload
- sourceEncoded :: Value
- sourceColumns :: PayloadColumns
- sourceParentId :: Maybe Int64
- sourceParentState :: Maybe Value
- sourceSuspended :: Bool
}
writeColumnNames :: [Text]
jobRowCodec :: Text -> RowCodec (JobRead Value)
dlqRowCodec :: Text -> RowCodec (Int64, UTCTime, JobRead Value)
archiveRowCodec :: Text -> RowCodec (Int64, UTCTime, JobRead Value, Maybe Value)
rateLimitPolicyViewCodec :: RowCodec RateLimitPolicyView
rateLimitBucketCodec :: RowCodec RateLimitBucketView
concurrencyPolicyViewCodec :: RowCodec ConcurrencyPolicyView
concurrencyKeyViewCodec :: RowCodec ConcurrencyKeyView
cronScheduleRowCodec :: RowCodec CronScheduleRow
workerRowWithHealthCodec :: RowCodec (WorkerRow, Text)
queueRowCodec :: RowCodec QueueRow

Column types

Source #data Col a where

Scalar PostgreSQL column type. The GADT tag recovers the Haskell type.

Constructors

CInt4 :: Col Int32
CInt8 :: Col Int64
CText :: Col Text
CBool :: Col Bool
CTimestamptz :: Col UTCTime
CJsonb :: Col Value
CFloat8 :: Col Double
CUuid :: Col UUID

Source #data NullCol a where

A named column with nullability. Carries the column name for backends that use name-based decoding (e.g. orville).

Constructors

NotNull :: forall a. Text -> Col a -> NullCol a
Nullable :: forall a1. Text -> Col a1 -> NullCol (Maybe a1)

Row decoding

Source #type RowCodec = Ap NullCol

Free applicative over NullCol. Backends interpret this into their native row parser by pattern-matching on each NullCol.

Source #col :: Text -> Col a -> RowCodec a

A non-nullable column.

Source #ncol :: Text -> Col a -> RowCodec (Maybe a)

A nullable column.

Source #runCodec :: Applicative f => (forall x. NullCol x -> f x) -> RowCodec a -> f a

Interpret a RowCodec by providing a natural transformation from NullCol to some Applicative.

Source #codecColumns :: RowCodec a -> [Text]

Extract the column names from a codec (in order).

Parameter encoding

Source #data ParamType a where

How a parameter is shaped: scalar, nullable, or array.

Constructors

PScalar :: forall a. Col a -> ParamType a
PNullable :: forall a1. Col a1 -> ParamType (Maybe a1)
PArray :: forall a1. Col a1 -> ParamType [a1]
PNullArray :: forall a1. Col a1 -> ParamType [Maybe a1]

Source #data SomeParam where

An existentially-typed parameter. A ParamType paired with its value.

Constructors

SomeParam :: forall a. ParamType a -> a -> SomeParam

Source #type Params = [SomeParam]

Positional query parameters.

Source #pval :: Col a -> a -> SomeParam

A non-null scalar parameter.

Source #pnul :: Col a -> Maybe a -> SomeParam

A nullable scalar parameter.

Source #parr :: Col a -> [a] -> SomeParam

A non-null array parameter.

Source #pnarr :: Col a -> [Maybe a] -> SomeParam

An array parameter with nullable elements.

Bidirectional job write codec

Source #data Codec s a

A profunctor codec. Writes source s to INSERT columns and params, decodes value a back.

Instances

Instances details

Applicative (Codec s) Source #
Instance details Defined in Arbiter.Core.Codec Methods #pure :: a -> Codec s a #(<>) :: Codec s (a -> b) -> Codec s a -> Codec s b #liftA2 :: (a -> b -> c) -> Codec s a -> Codec s b -> Codec s c #(>) :: Codec s a -> Codec s b -> Codec s b #(<*) :: Codec s a -> Codec s b -> Codec s a
Functor (Codec s) Source #
Instance details Defined in Arbiter.Core.Codec Methods #fmap :: (a -> b) -> Codec s a -> Codec s b #(<$) :: a -> Codec s b -> Codec s a

Source #cDecode :: Codec s a -> RowCodec a

The read side.

Source #cColumns :: Codec s a -> [(Text, Text)]

Writable (column name, PostgreSQL type) pairs, in order.

Source #cScalar :: Codec s a -> s -> Params

Single-row parameters, one per column.

Source #cArray :: Codec s a -> [s] -> Params

Batch parameters, one array per column.

Source #jobCodec :: Text -> Codec (JobWriteSource payload) (JobRead Value)

Main-table codec. The write source contains public enqueue fields, payload columns, parent id, rollup state, and suspension state.

Source #data JobWriteSource payload

The insert side of a job row. The payload encoding is built once by the caller.

Constructors

JobWriteSource
Fields sourceJob :: JobWrite payload sourceEncoded :: Value sourceColumns :: PayloadColumns sourceParentId :: Maybe Int64 sourceParentState :: Maybe Value sourceSuspended :: Bool