xaRecover method

List<Xid>? xaRecover(int connectionId)

xa_recover: list every XID currently in the XaState.prepared state on the resource manager. Used after process restart to discover branches awaiting a Phase 2 decision.

Resume each XID with xaResumePrepared and call XaTransactionHandle.commitPrepared / XaTransactionHandle.rollbackPrepared per the Transaction Manager's recovery decision.

Returns an empty list when no prepared XIDs exist; returns null on FFI failure (call getStructuredErrorForConnection).

Implementation

List<Xid>? xaRecover(int connectionId) {
  final count = _native.xaRecoverCount(connectionId);
  if (count < 0) return null;
  final out = <Xid>[];
  for (var i = 0; i < count; i++) {
    final entry = _native.xaRecoverGet(i);
    if (entry == null) continue;
    // Xid() throws ArgumentError on length violations. We *want* to
    // catch that and skip the entry — those XIDs belong to a
    // different client that violated the X/Open length limits, and
    // we don't want recovery to abort over an unrelated bad
    // neighbour.
    try {
      out.add(
        Xid(
          formatId: entry.formatId,
          gtrid: entry.gtrid,
          bqual: entry.bqual,
        ),
      );
      // Catching `Error` is unidiomatic in general, but here the
      // error path is data-driven (a bad neighbour client wrote a
      // malformed prepared XID) and we explicitly want to skip,
      // not crash recovery.
      // ignore: avoid_catching_errors
    } on ArgumentError {
      // intentionally silent — see comment above
    }
  }
  return out;
}