Folder-sync app

This sample-app allows peers to join a shared folder, where each user will own a folder named as their username. The local peer can drop new files to its folder, where a filewatcher will automatically detect new files and sync to other joined peers.

Design

The main components of the applications are:

• A Store using new Threads V2.
• IPFS Lite to download files.

The Store will hold all files metadata, which is a JSON document derived from the following structure:

type userFolder struct {
	ID    core.EntityID
	Owner string
	Files []file
}

type file struct {
	ID               string
	FileRelativePath string
	CID              string

	IsDirectory bool
	Files       []file
}

In summary, each folder is represented by a userFolder which is owned by a user. This folder has a list of file which has file metadata such as:

• A unique uuid
• A relative path from the root of the shared folder: userXXX/file.txt
• The CID of the file, which can be fetched out-of-band with IPFS Lite.

The original intention is to allow arbitrary nested folders and files, but currently it has only one level support for files. It's on the plans to enable folder discovery to allow nested trees.

Currently, when a new file is discovered by a peer, it will try to fetch it using an ipfslite client, which will leveraged connected peers. By default, the ipfslite peer doesn't boostrap a DHT, but it can be enabled in a single line. Future versions will make this optional through flags. In the same vein, we can provide other sources from which fetch files such as the Filecoin network.

Usage

When a peer wants to bootstrap a new shared folder, to invite others, it has to run: go run main.go util.go client.go -name bob. This will create a new Store with an underlying new Thread, and will print an invitation link that other peers can use to join the shared folder.

Joining peers will run: go run main.go util.go client.go -name alice -inviteLink xxxxxxx to join the shared folder. The invite link has format: <thread-addr>?<follow-key>&<read-key>.

Current flags are:

• name: to setup the peer name, which will be his sharedfolder name
• repo: path to the repo that will hold data of Store
• sharedFolder: path to where will be the shared folder containing all peer folders with their files
• inviteLink: if provided is used to join an existing sharedFolder

Flags have reasonable defaults.

Tests

This app now has a pretty heavy test setup, where tunning a parameter simulates:

• A number N of peers joining a shared folder
• How many random files will each peer generate
• How big each random file will be
• How many core peers will be used to join the sharedFolder. This means, X peers will be used as invitation links by others in a round-robin fashion possibly to avoid DoSing all joining the same peer. May also be used to test how this impact syncing perf.
• How many seconds provide to the peers to sync before asserting convergence.

After the sync timeout triggers, the test will assert if all Store of peers are the same, and if all the files were fetched (that to say, each peer shared folder contains all peers folders and their files).

Take into consideration that tests configuration should be tuned to avoid timeouts and high overload, since all peers are running on the same host.