treelogy

Installation

yarn add treelogy --save

About

Treelogy is a simple versioning framework.

• Treelogy is inspired by class inheritance in various programming languages
• Uses a version tree to keep track of changes
• Each version contains atomic parts called nodes
• The node can contain any type of data and could be overridden in child version
• Each node contains only delta, thus minimizing the memory footprint

Demos

Check the treelogy-demo project for online examples.

Class inheritance example

I'm using C# here because of its explicit modifiers, to better illustrate the point.

class Version_1
{
    public virtual string foo()
    {
        return 'foo';  
    }

    public virtual string bar()
    {
        return 'bar';  
    }
}

class Version_2 : Version_1
{
    // method foo() is implicitly present by inheritance 

    // overriden method
    public override string bar()
    {  
        return 'bar_2';  
    }

    // new method
    public virtual string baz()
    {  
        return 'baz';  
    }
}

In the above example, class Version_2 inherits from Version_1.

It overrides the method bar, providing own implementation.

Additionally it introduces a new method baz.

Treelogy example

Treelogy is a store containing a number of versions, where each version keeps track of its parent version.

For given version ID, Treelogy has the ability of processing all the ancestor deltas in order to build each version in full.

import Treelogy from "treelogy";

const demo = () => {
  const treelogy = new Treelogy();

  const version1 = treelogy.createVersion("Version_1");
  version1.createNode("foo", "foo"); // ID, data
  version1.createNode("bar", "bar");

  const version2 = treelogy.createVersion("Version_2", "Version_1"); // Version_2 inherits from Version_1
  tree2.updateNode("bar", "bar_2"); // overriden node
  tree2.updateNode("baz", "baz"); // new node

  // builds an array of processed versions
  // each version contains a full set of nodes, set of inherited IDs and set of overridden IDs
  const data = treelogy.process();

  // finding a particular version
  const version_1 = data.find(version => version.id === 'Version_1');
};

Build

If forking the library, you might want to build.

yarn build