Transaction Priority System

[heifner]

Summary

WIRE-195

This PR implements a transaction priority system, allowing sysio system contract to configure custom priorities (increase or decrease) for transactions based on their actions.

Changes

System Contract (sysio.system)

• Added transaction priority table and actions (contracts/sysio.system/include/sysio.system/trx_priority.hpp, contracts/sysio.system/src/trx_priority.cpp)
  • trxpriority table: Stores priority configurations with receiver, action name, match type, and priority value
  • trxpglobal singleton: Tracks last update timestamp for cache invalidation
  • addtrxp action: Register new transaction priority rules (requires system authority)
  • deltrxp action: Remove existing priority rules (requires system authority)
  • Supports three match types:
    • only: Matches transactions with exactly one action
    • first: Matches the first action in a transaction
    • any: Matches any action in a transaction
  • Priority range: -32,768 to 32,767 (negative values deprioritize below default)

Producer Plugin

• Added trx_priority_db component (plugins/producer_plugin/include/sysio/producer_plugin/trx_priority_db.hpp, plugins/producer_plugin/src/trx_priority_db.cpp)
  • Thread-safe database for retrieving transaction priorities
  • Automatically refreshes from system contract table every 1000 blocks on LIB signal
  • Efficient lookup using flat_multimap indexed by receiver account
  • Implements priority matching logic with exact action name precedence over wildcards
  • 30ms timeout for deserialization to prevent blocking

When merged with #163 the priority values will not interfere with non-trx priority tasks. Requires #163.