[WIP] doc: Files API

[schomatis]

This is a work in progress, I don't have a clear idea of the final form of this document, for now it is placeholder for any information I want to provide to the user while studying the Files API. Much of that information may not ultimately belong here but for the ease of the development process I'm centralizing it all (to avoid raising many PRs scattered through different repos).

[schomatis]

Hey @nitishm, this is something I should have finished a looong time ago, but since you mentioned you were interested in ipfs add to understand the code flow and you are proficient in Go I think you'd be perfect to help me move this PR forward which aimed to do exactly that, explain some go-ipfs internals through basic commands like ipfs add.

A good first step would be to follow the calls through ipfs add and try to identify the most important operations going on (e.g., we take the file and chunk it in some-function, we then organize the chunks in a DAG in some-other-function, we save them in the MFS, etc). Here is some (really incomplete) documentation about how we organize files in IPFS (any questions/clarifications you ask while reading that would be invaluable): https://github.com/ipfs/go-mfs#documentation. Besides just following the code with the IDE what really helped when I was starting was following it with a debugger like Delve (#5274 (comment)) for reasons like we use some interface indirections that are really tough to follow in the static code, our package manager is not great for beginners yet and some pieces of code can be hard to find (and as usual, seeing the code in action with actual values is really helpful to get concrete examples while reasoning about the code).

Give this a try and feel free to ask any number and sort of questions (open any issues/PRs you need and tag them under this milestone).

[nitishm]

@schomatis This is something I definitely feel comfortable doing. I have been using dlv with my IDE to follow the flow of ipfs add. (I should've really written it down yesterday. God dang!)
Where exactly do you want me to capture the flow ?

Here is some (really incomplete) documentation about how we organize files in IPFS (any questions/clarifications you ask while reading that would be invaluable): https://github.com/ipfs/go-mfs#documentation.

I will add my thoughts and questions as I go through the code once again.

[schomatis]

Great!

Where exactly do you want me to capture the flow ?

For now, open a separate PR (or issue, whatever feels best to write a simple document) tagging this milestone since I'm not sure I can give you permissions to push to this one.

[nitishm]

@schomatis How can I tag my issue #5858 with the milestone ?

[schomatis]

Closing in favor of #5864.