Method rollback

src/transaction/transaction_manager.cpp:179–196

Note: We take in additional `transaction` here is due to that `transactionContext` might be destructed when a transaction throws an exception, while we need to roll back the active transaction still.

// destructed when a transaction throws an exception, while we need to roll back the active
// transaction still.
void TransactionManager::rollback(main::ClientContext& clientContext, Transaction* transaction) {
    std::unique_lock lck{mtxForSerializingPublicFunctionCalls};
    clientContext.cleanUp();
    switch (transaction->getType()) {
    case TransactionType::READ_ONLY: {
        clearTransactionNoLock(transaction->getID());
    } break;
    case TransactionType::RECOVERY:
    case TransactionType::WRITE: {
        transaction->rollback(&wal);
        clearTransactionNoLock(transaction->getID());
        activeWriteTransactionCount.fetch_sub(1, std::memory_order_release);
    } break;
    default: {
        throw TransactionManagerException("Invalid transaction type to rollback.");
    }
    }
}

void TransactionManager::checkpoint(main::ClientContext& clientContext) {
    if (clientContext.isInMemory()) {