2021-11-05 Example console demo

[leighmcculloch]

Here's video demo of a payment channel using CAP-21 and CAP-40 working on a test network between @acharb and I.

It is the examples/console app using the sdk package at 9dbede9.

The SDK at its core is the sdk/state package, which is a state machine that produces and verifies agreements. The goal of the state package is to make the channel safe, so it will reject agreements that leave it in an unsafe state. The current implementation optimizes for simplicity rather than flexibility, and therefore only accepts a single payment at a time.

The SDK also has the sdk/agent package, and a few other peripheral package, that have logic to handle setting up a TCP connection and negotiating the open, payments, ingestion, and close processes. The agent can ingest transactions from Horizon, or any other source. The agent is currently intended for use building examples, benchmarks, and experiments.

The sdk/agent/bufferedagent package wraps an agent and provides an implementation of buffered payments as described in #330 (comment).

Payments are buffered while the last payment is in flight and then sent together in a single agreement. This puts the network bandwidth available to use to get fast finality on a large number of payments at the same time.

Using buffered payments we've been able to get over 1 million TPS 🎉 .

In the video we saw 1.2 million TPS, and when recording the test values for capturing in a report, we saw 1.1 million to 1.5 million TPS.

Report: https://github.com/stellar/starlight/blob/main/benchmarks/Benchmark%20Report%202021-11-05.md

2021-11-05.-.Example.console.app.demo.mp4