Unified content block construction (WIP)

[lrettig]

Overview

As part of the Spacemesh transaction selection and processing workflow (#50, #37), the Spacemesh protocol specifies that all of the proposals (submitted by eligible Smeshers in a given layer) be assembled into a single, unified content block (hereinafter referred to simply as the "block") for that layer. This proposal describes the deterministic algorithm by which this happens.

Goals and motivation

Specify a simple, deterministic algorithm that takes as input a set of valid proposals, each containing zero or more transactions, and outputs a single block of ordered transactions. Drop (i.e., do not include in output) transactions that are invalid or won't be effective (i.e., won't pay any gas) if possible.

High-level design

• Take the union of all input transactions
• Drop invalid transactions
• Sort deterministically by principal, using a pseudorandom seed
• Cluster transactions by principal and subsort by nonce
• Drop duplicate transactions
• Simulate execution of transactions, in order, against most recent known state (when/if known) and drop transactions that are ineffective
• Assemble the filtered, sorted transactions into an output block

Prior art

Proposed implementation

Implementation plan

Questions

Dependencies and interactions

• Transaction Processing #37
• Transaction Selection #50

Stakeholders and reviewers

Testing and performance