Suo DB

Suo (suomi: swamp) is document oriented DB.

[TOC]

Status

!!! Important! Despite it's already using in production on some projects, it still in heavly development stage.

It means that API may changes, and currenty not tested as well as should.

Please keep it in mind.

MonoRepo

There is a root repo that contains a two main repos inside:

• suo - this library
• suo_generator - generator helper for declarative style DTOs
• simple_example - example usage of thge lib

Main concept

Description

It's platform agnostic DB is developing with dart language.

Main concept of this storage it's provide possibility to store any structures and make easy search by them, therefore in the docstorage we use indexing. Index is a structure that made for icrease datata retrieval speed, a bit detailed below.

Indexing

Current index implementation allows us to retrieve a document with indexed value in O(1) access time. Cuz index storing implemented by the hash set of keys and pointers. Physicaly index files stores in .idx files inside index direcory and have a structure like this.

entity_storage/
    index/
        index_name.idx
        index_name2.idx
        etc..

inside index file we have a following view:

index_value:link_1,link2,link3
index_value2:link_4,link_6,
index_valueN:link_x,link_z

etc..

where link_n is pointer (id) on exact document;

Index and IndexedEntity are classes that helps us to create this shit.

Index<V,I> is functional-based index. that keep two field inside name and indexFunction. IndexEntity<V,I> is wrapper around your primary DTO, that consist value list of indicies and computable field id its field something like primary key. as is a computable it could be composed key. but in generarall it have to be id of your DTO.

Instalation

Since it has not been published yet you should add it as git dependency in your pubspec.yaml

dependencies:
  suo:
    git:
      url: [email protected]:NiKoTron/suo.git
      path: suo

If you whant to use code generation feature you should also add a suo_generator in your dev_dependencies

dev_dependencies:
  suo:
    git:
      url: [email protected]:NiKoTron/suo.git
      path: suo_generator

Usage

Basic usage looks like this:

First of all we should create indexed wrapper for our DTO object.

class SomeObj {
    String id;

    String foo;
    String bar;
    String baz;

    SomeObj.fromJson(String json) // create instance from json
    toJson() => // convert to json...
}

class IndexedObj extends IndexedEntity<SomeObj, String> {

  IndexedBike(value) : super(
      value, // dto value
      (v) => v.id, // id
      [
        Index('foo', (v) => '${v?.foo}'),
        Index('foobaz', (v) => '${v?.foo}_${v?.baz}')
      ]);
}

Initialisation of storage.

For each type of object, we have to create their own docstorage with a unique directory.

We should pass four parameters to create storage instance:

The directory where data files will managing. Deserialiser and serialiser like in Suo above. Indexed factory is a function that makes an IndexedEntity wrapper instance for our DTO.

License

This package is dveloping under MIT license

Credits

Main contributor: Nikolai Simonov [email protected]