top of book feature

[pabx06]

i was wondering how to efficiently get the top line of bids and asks without iteration over all the keys . sinc asks and bis ar stored as one big object instead of an array of object. Also a new event when the top1 of bid/ask change will be helpful too...

[tzurbaev]

Hi, @pabx06!

This package was created for one of my projects that is currently frozen and unfortunately I have no time to provide code updates at this moment.

If you can make PR for requested changes, I would glad to review them and merge.

Some hints:

• If by "the top line of bids/asks" you mean the most recent update, you can listen to the update event - raw payload from Bittrex will be it's first argument (see https://github.com/tzurbaev/bittrex-orderbook-manager/blob/master/src/BittrexOrderBook.js#L224);
• Or if you need to get biggest/lowest rate, you can do something like this:

  const minBidsRate = Math.min(...Object.keys(orderBook.orders.bids))
  const maxBidsRate = Math.min(...Object.keys(orderBook.order.bids))

• If the biggest/lowest rates are what you're looking for, then you can check & update rates in BittrexOrderBook.addOrder and emit this new event if something changes:

if (item.rate > this.lowestBidsRate) {
    this.emit('lowestRateUpdated', { side: 'bids', rate: item.rate})
    this.lowestBidsRate = item.rate
}

[pabx06]

exactly what i was thinking biggest bid and lowest ask. also would be nice to make the orderbook generic enough to plug it on other exchanges implementations. and swap signalr-client for @discordjs/uws websocket tiny memory footprint