pail-fressian

Serialization and partitioning strategies for using data.Fressian with clj-pail. This library is modeled after pail-thrift which it shares many commonalities. Serialization is not currently set up to use different Fressian handlers and unlike pail-thrift there are no protocols to be had.

Usage

Add pail-fressian to your project's dependencies. If you're using Leiningen, your project.clj should look something like this:

(defproject ...
  :dependencies [[pail-fressian VERSION]])

Where VERSION is the latest version on Clojars.

Defining a PailStructure

PailStructure classes are defined with the gen-structure macro from clj-pail. pail-fressian provides serializers and partitioners that can be used with the gen-structure macro.

(ns example.pail
  (:require [clj-pail.structure :refer [gen-structure]]
            [pail-fressian.serializer :as s]
            [pail-fressian.partitioner :as p])
  (:gen-class))

(gen-structure example.pail.PailStructure
               :serializer (s/fressian-serializer)
               :partitioner (p/fressian-partitioner))

In the above example, we define a PailStructure that can serialize any native data type using Fressian read and write. The PailStructure will also be vertically partitioned by the first field of each data object.

Vertical Partitioning

A PailStructure is vertically partitioned according to the partitioner supplied as the :partitioner keyword argument of gen-structure. pail-fressian provides somewhat generic partitioners, but you will most likely want to create a partitioner specific to your application.

Generalized partitioners are defined in pail-fressian.partitioner. Currently, there are 2 partitioners. Both of them are somewhat contrived.

One uses the first property name of the data object to create a single level partitioning scheme. The other uses the type name of the data object, while also looking specifically for anything ending in [Pp]roperty, When found it looks for a possible second level of partitioning in a :property field. Due to the open nature of a fressian pail these partitioners are truly only examples of how to proceed in making your own application specific partitioner. Both partitioners short-circuit partition validation as almost anything goes here, and there is no type to check.

If you have ideas about better generic partitioners, validation or improvements please fork me.

License

Copyright © 2014 Eric Gebhart

Distributed under the MIT License.