serai/processor/scheduler/utxo/transaction-chaining

Transaction Chaining Scheduler

A scheduler of transactions for networks premised on the UTXO model which support transaction chaining. Transaction chaining refers to the ability to obtain an identifier for an output within a transaction not yet signed usable to build and sign a transaction spending it.

Design

The scheduler is designed to achieve fulfillment of all expected payments with an O(1) delay (regardless of prior scheduler state), O(log n) time, and O(log(n) + n) computational complexity.

Due to the ability to chain transactions, we can immediately plan/sign dependent transactions. For the time/computational complexity, we use a tree to fulfill payments. This quickly gives us the ability to make as many outputs as necessary (regardless of per-transaction output limits) and only has the latency of including a chain of O(log n) transactions on-chain. The only computational overhead is in creating the transactions which are branches in the tree.