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deserialize_command_for_replay

hypercall::nats::deserialize

Function deserialize_command_for_replay 

Source 
pub(crate) fn deserialize_command_for_replay(
    cmd_type: CommandType,
    command_version: u8,
    data: &[u8],
) -> Result<EngineCommand>
Expand description

Deserialize a persisted engine command during restart recovery.

This intentionally has a narrower compatibility surface than live NATS. The source-hash cutover changed DepositUpdate from BalanceCommandPayload to DepositUpdatePayload, but existing WAL rows can still contain the old named payload. Recovery accepts only that persisted shape and only when a sequence exists, so live messages stay on the new deterministic source-hash contract.

Compatibility exception audit:

  • Tracking ticket: CALL-1900.
  • Environment: AWS staging restart recovery after PR #2555, observed at command_id=284965 with command_data_len=73.
  • Historical shape: legacy wire-version tuple (WalletAddress, Decimal amount, Decimal balance_after, u64 timestamp_ms, Option<u64> sequence).
  • Hard cutover risk: staging cannot boot far enough to replay the journal and write a current snapshot while the historical WAL row is undecodable.
  • Removal plan: remove the legacy tuple branch after AWS staging boots on the hotfix image, replays the row, writes a compatible snapshot, and restarts without ENGINE_SNAPSHOT_RESTORE_ALLOW_UNSAFE_REPLAY=true.