Build a real file system provider

[jrieken]

This to make #29194 and the goal is to build a file system provider that connects to a FTP server. We want to support the following things

• stuff works with scheme, not authority
• show remote files in the explorer like normal files
• allow read, write, and delete files
• allow to list, create, delete folders

The outcome of this is a more mature and complete (internal and external) API and a sample that illustrates how to use it. And last but not least this is to identify debt and false-assumptions about running on a (local) file system.

[siegebell]

I've been playing around with this and it looks very promising -- thanks!

@jrieken At the moment, it takes several seconds to load the file system in the explorer :(. Maybe you can change the API to allow batching multiple operations, or else have a readtree command that has a depth argument?

[siegebell]

Here is @jrieken's ftp example.

[jrieken]

Maybe you can change the API to allow batching multiple operations, or else have a readtree command that has a depth argument?

The challenge with readtree is that it easily leads to a tree-model of stats and that I want to avoid

[jrieken]

@jrieken At the moment, it takes several seconds to load the file system in the explorer

There was actually an issue that would always stat way too much... We have fixed that in https://github.com//Microsoft/vscode/commit/22170c2bf665c30119c3aabd67326871c7c1e378 and things should be a lot faster, esp with large directories.

Wrt 'readtree' I'd like to point out that our readdir call is something like 'readddirplus' which doesn't only return filenames but also it's stat. That keeps the number of round trips low.

[jrieken]

I am closing this issue now as the whole remote thing has become bigger and this particular issue isn't actionable. We have the ftp sample in its own repo and in this repo we use the remote-label as well as todo@remote comments