postgresql-simple-queue: A PostgreSQL backed queue

[ bsd3, library, web ] [ Propose Tags ]

This module utilize PostgreSQL to implement a durable queue for efficently processing arbitrary payloads which can be represented as JSON.

Typically a producer would enqueue a new payload as part of larger database transaction

 createAccount userRecord = do
    'runDBTSerializable' $ do
       createUserDB userRecord
       'enqueueDB' $ makeVerificationEmail userRecord

In another thread or process, the consumer would drain the queue.

  forever $ do
    -- Attempt get a payload or block until one is available
    payload <- 'lock' conn

    -- Perform application specifc parsing of the payload value
    case fromJSON $ 'pValue' payload of
      Success x -> sendEmail x -- Perform application specific processing
      Error err -> logErr err

    -- Remove the payload from future processing
    'dequeue' conn $ 'pId' payload

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Modules

[Last Documentation]

Database
- PostgreSQL
  - Simple
    - Database.PostgreSQL.Simple.Queue
      - Examples
        Database.PostgreSQL.Simple.Queue.Examples.EmailQueue
      - Database.PostgreSQL.Simple.Queue.Main
      - Database.PostgreSQL.Simple.Queue.Migrate

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postgresql-simple-queue-0.1.0.0.tar.gz [browse] (Cabal source package)
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JonathanFischoff

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Versions [RSS]	0.1.0.0, 0.1.0.1, 0.2.0.0, 0.2.1.0, 0.3.0.0, 0.4.0.0, 0.5.0.0, 0.5.0.1, 0.5.1.0, 0.5.1.1, 1.0.0, 1.0.1
Dependencies	aeson, amazonka, amazonka-ses, base (>=4.7 && <5), bytestring, data-default, exceptions, lens, lifted-async, lifted-base, monad-control, optparse-generic, pg-transact, postgresql-simple, postgresql-simple-opts, postgresql-simple-queue, random, resource-pool, text, time, transformers, uuid [details]
License	BSD-3-Clause
Copyright	2017 Jonathan Fischoff
Author	Jonathan Fischoff
Maintainer	jonathangfischoff@gmail.com
Category	Web
Home page	https://github.com/jfischoff/postgresql-queue#readme
Source repo	head: git clone https://github.com/jfischoff/postgresql-queue
Uploaded	by JonathanFischoff at 2017-06-17T05:07:38Z
Distributions
Reverse Dependencies	1 direct, 0 indirect [details]
Executables	async-email-example
Downloads	7163 total (48 in the last 30 days)
Rating	(no votes yet) [estimated by Bayesian average]
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Status	Docs not available [build log] All reported builds failed as of 2017-06-17 [all 3 reports]

Readme for postgresql-simple-queue-0.1.0.0

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postgresql-simple-queue

This module utilize PostgreSQL to implement a durable queue for efficently processing arbitrary payloads which can be represented as JSON.

Typically a producer would enqueue a new payload as part of larger database transaction

createAccount userRecord = do
  runDBTSerializable $ do
    createUserDB userRecord
    enqueueDB $ makeVerificationEmail userRecord

In another thread or process, the consumer would drain the queue.

  forever $ do
    -- Attempt get a payload or block until one is available
    payload <- lock conn

    -- Perform application specifc parsing of the payload value
    case fromJSON $ pValue payload of
      Success x -> sendEmail x -- Perform application specific processing
      Error err -> logErr err

    -- Remove the payload from future processing
    dequeue conn $ pId payload