Does the leader need to go through socket?

[ronag]

Couldn't the leader use the db directly?

[ronag]

I guess I don't understand this part:

party/index.js

Lines 104 to 114 in 6d5dc4f

	if (client.isFlushed()) {
	return
	}
	const sock = net.connect(sockPath)
	pump(sock, client.createRpcStream(), sock, function () {
	// TODO: err?
	})
	client.once('flush', function () {
	sock.destroy()
	})

[ronag]

Also, are we missing a ref: socket here?

party/index.js

Line 109 in 6d5dc4f

pump(sock, client.createRpcStream(), sock, function () {

Actually why do we even need ref: socket? pipeline should/will destroy.

[vweevers]

Couldn't the leader use the db directly?

It does, 99% of the time.

I guess I don't understand this part

That's to counter the fact that the party starts after the publicly consumed db (i.e. multileveldown.client()) has opened itself. So at that point there could already be pending requests (from e.g. a db.put() call) that, even when the db is a leader, must be flushed, as if the db is not a leader. It's ugly and I want to refactor this - once I understand the ref thing.

As for why we don't need ref in this code path: I think because we're expecting to have to flush only a few early requests, after which the socket can be destroyed.

[vweevers]

Actually why do we even need ref: socket? pipeline should/will destroy.

If a ref is provided, we unref that after having received responses to all pending requests, meaning there are no active db operations left that should keep the event loop alive (matching regular level behavior). Once a new db operation is made, we re-ref.

I discovered a small bug here: we don't initially unref. You must make at least one db operation for it to work. So this hangs:

const name = Date.now().toString()

const db1 = party(name)
const db2 = party(name)

await db1.open()
await db2.open()

console.log('opened')

// Comment this out to not make the event loop hang
// await db1.put('a', 'b')
// console.log(await db2.get('a'))