ZeroTierOne/ext/libpqxx-7.7.3/test/test29.cxx
2022-06-22 15:03:19 -07:00

109 lines
3.0 KiB
C++

#include <cstdio>
#include <iostream>
#include <vector>
#include <pqxx/nontransaction>
#include <pqxx/transaction>
#include "test_helpers.hxx"
using namespace pqxx;
// Test program for libpqxx. Open connection to database, start a transaction,
// abort it, and verify that it "never happened."
//
// The program will attempt to add an entry to a table called "pqxxevents",
// with a key column called "year"--and then abort the change.
namespace
{
// Let's take a boring year that is not going to be in the "pqxxevents" table
constexpr int BoringYear{1977};
std::string const Table{"pqxxevents"};
// Count events, and boring events, in table
std::pair<int, int> CountEvents(transaction_base &tx)
{
std::string const events_query{"SELECT count(*) FROM " + Table};
std::string const boring_query{
events_query + " WHERE year=" + to_string(BoringYear)};
return std::make_pair(
tx.query_value<int>(events_query), tx.query_value<int>(boring_query));
}
// Try adding a record, then aborting it, and check whether the abort was
// performed correctly.
void Test(connection &conn, bool ExplicitAbort)
{
std::vector<std::string> BoringRow{to_string(BoringYear), "yawn"};
std::pair<int, int> EventCounts;
// First run our doomed transaction. This will refuse to run if an event
// exists for our Boring Year.
{
// Begin a transaction acting on our current connection; we'll abort it
// later though.
work Doomed(conn, "Doomed");
// Verify that our Boring Year was not yet in the events table
EventCounts = CountEvents(Doomed);
PQXX_CHECK_EQUAL(
EventCounts.second, 0,
"Can't run; " + to_string(BoringYear) + " is already in the table.");
// Now let's try to introduce a row for our Boring Year
Doomed.exec0(
"INSERT INTO " + Table +
"(year, event) "
"VALUES (" +
to_string(BoringYear) + ", 'yawn')");
auto Recount{CountEvents(Doomed)};
PQXX_CHECK_EQUAL(Recount.second, 1, "Unexpected number of events.");
PQXX_CHECK_EQUAL(
Recount.first, EventCounts.first + 1, "Number of events changed.");
// Okay, we've added an entry but we don't really want to. Abort it
// explicitly if requested, or simply let the Transaction object "expire."
if (ExplicitAbort)
Doomed.abort();
// If now explicit abort requested, Doomed Transaction still ends here
}
// Now check that we're back in the original state. Note that this may go
// wrong if somebody managed to change the table between our two
// transactions.
work Checkup(conn, "Checkup");
auto NewEvents{CountEvents(Checkup)};
PQXX_CHECK_EQUAL(
NewEvents.first, EventCounts.first, "Wrong number of events.");
PQXX_CHECK_EQUAL(NewEvents.second, 0, "Found unexpected events.");
}
void test_029()
{
connection conn;
{
nontransaction tx{conn};
test::create_pqxxevents(tx);
}
// Test abort semantics, both with explicit and implicit abort
Test(conn, true);
Test(conn, false);
}
PQXX_REGISTER_TEST(test_029);
} // namespace