Farm Controller

Quick start

git clone git@github.com:untitledlt/farm.git
cd farm
yarn install
yarn test

Usage

const farm = new ChainFarm();

const calveA1 = farm.giveBirth(0, farm.nextId(), 'First calve');
const calveA2 = farm.giveBirth(0, farm.nextId(), 'Second calve');
const calveA3 = farm.giveBirth(0, farm.nextId(), 'Third calve');

const calve11 = farm.giveBirth(calveA1.cowId, farm.nextId(), 'Litter calveA1->B');

// so sad :'(
farm.endLifeSpan(calveA3.cowId);

farm.print();

Implementations

There are 5 implementations with different data types to control the farm. First 4 uses Array/Object/Map data types and the last one is my custom data structure implementation for Task's part #2.

1.1. Array

Implemented in file 1.1.ArrayFarm.ts

This method uses two Arrays to store primitive values:

• cow[index] = name
• parentMap[index] = parentId

This is the least convenient way to store/access data but it's the fasters method to read/insert data. It has downsides (f.e. incorrect lenght) when some elements are deleted as it still keeps undefined items.

1.2. Array of Object

Implemented in file 1.2.ArrayOfObjectsFarm.ts

This could be quite simple and convienient way to store data but it has super slow findCowById method because it needs to iterate Array until it finds required item. Probably I would use this method is speed was not an issue.

1.3. Object

Implemented in file 1.3.ObjectFarm.ts

Fast and most convenient method to store/access data. Requires addition parsing because index is stored in property name so it's a string.

1.4. Map

Implemented in file 1.4.MapFarm.ts

Most modern data type. A little bit nicer way to store/access data but it's slower then Object.

2.1. Chain

Implemented in file 2.1.ChainFarm.ts

This method does NOT use Array/Object type to store data

This is a solution to part 2 of this task.

It was inspired by my LRU cache implementation: https://github.com/untitledlt/currency-exchange-api/blob/main/src/LruCache/LruCache.ts

Method getList uses an Array but it's used only for debuging. Actual data structure does NOT use Array.

Data is stored in ChainCow instance as primitive values (no Array/Object). Each instance has a reference to next/previous record so all cows are connected to the chain to make it possible to iterate over each element.

Performance comparition

Class Name	Insert	Find	Delete	Total time
1.1. ArrayFarm	0.203 μs	0.111 μs	0.137 μs	45.1 ms
1.2. ArrayOfObjectsFarm	154.488 μs	62.922 μs	119.549 μs	33695 ms
1.3. ObjectFarm	0.477 μs	0.242 μs	0.143 μs	86.22 ms
1.4. MapFarm	0.580 μs	0.694 μs	0.120 μs	139.38 ms
2.1. ChainFarm	464.698 μs	274.855 μs	275.0 μs	101455.37 ms

Insert method also does 2x findCowById to validate data

Delete method also does 1x findCowById to validate data

Total time column represents total time in miliseconds of all iterations (100.000)

Other information

• All implementations extends base Farm class which has print method.

• File debug.ts contains some messy code that I used to test implementations, measure performance, etc.

• Folder coverage has unit tests coverage report