cristianchaparroa/golang-challenge

Golang-Challenge

Challenge test

We ask that you complete the following challenge to evaluate your development skills.

The Challenge

Finish the implementation of the provided Transparent Cache package.

Show your work

1. Create a Private repository and share it with the recruiter ( please dont make a pull request, clone the private repository and create a new private one on your profile)
2. Commit each step of your process so we can follow your thought process.
3. Give your interviewer access to the private repo

What to build

Take a look at the current TransparentCache implementation.

You'll see some "TODO" items in the project for features that are still missing.

The solution can be implemented either in Golang or Java ( but you must be able to read code in Golang to realize the exercise )

Also, you'll see that some of the provided tests are failing because of that.

The following is expected for solving the challenge:

• Design and implement the missing features in the cache
• Make the failing tests pass, trying to make none (or minimal) changes to them
• Add more tests if needed to show that your implementation really works

Deliverables we expect:

• Your code in a private Github repo
• README file with the decisions taken and important notes

Time Spent

We suggest not to spend more than 2 hours total, which can be done over the course of 2 days. Please make commits as often as possible so we can see the time you spent and please do not make one commit. We will evaluate the code and time spent.

What we want to see is how well you handle yourself given the time you spend on the problem, how you think, and how you prioritize when time is insufficient to solve everything.

Please email your solution as soon as you have completed the challenge or the time is up.

Solution

1. The TransparentCache doesn't have a way to verify if the maxAge will be after the elapsed time of cache. For that reason I added a field called startAge to be able to calculate if the maxAge was after the startAge.

2. At some point the solution was good but, It wasn't able to re-start the time after the startAge was greater than maxAge, and It was a problem, reason because I create the function resetStartAge, to be to cache the prices again. Those points solve the first todo.

3. Adding a go routine in the GetPricesFor function allows to parallelize the query for each itemCode. I created a channel in which I added the prices and also another for handle errors. The channels allow me to keep the results.