Merge #16563: test: Add unit test for AddTimeData

7cd069d8ef900c6c6b904ddd6fbd64e14bd0f53e Add test for AddTimeData (Martin Zumsande)

Pull request description:

  `AddTimeData()` has poor test coverage but interesting logic (including a bug turned into a feature). This PR adds a unit test for it.

ACKs for top commit:
  laanwj:
    ACK 7cd069d8ef900c6c6b904ddd6fbd64e14bd0f53e, thanks for adding a test

Tree-SHA512: 8228f9027e52ed534411d595c7e45cf4edeee9757f26f5141fbcfae3fc6f598a8cea7f734bb8f55238857a37ad2f2d518e859e1fe8c106c0712da976792ac132
This commit is contained in:
Wladimir J. van der Laan 2019-08-14 14:32:03 +02:00 committed by Pasta
parent 7dca136101
commit 0cb1a9d39f
No known key found for this signature in database
GPG Key ID: 52527BEDABE87984

View File

@ -2,8 +2,14 @@
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
//
#include <timedata.h>
#include <netaddress.h>
#include <noui.h>
#include <test/setup_common.h>
#include <timedata.h>
#include <warnings.h>
#include <string>
#include <boost/test/unit_test.hpp>
@ -34,4 +40,61 @@ BOOST_AUTO_TEST_CASE(util_MedianFilter)
BOOST_CHECK_EQUAL(filter.median(), 7);
}
static void MultiAddTimeData(int n, int64_t offset)
{
static int cnt = 0;
for (int i = 0; i < n; ++i) {
CNetAddr addr;
addr.SetInternal(std::to_string(++cnt));
AddTimeData(addr, offset);
}
}
BOOST_AUTO_TEST_CASE(addtimedata)
{
BOOST_CHECK_EQUAL(GetTimeOffset(), 0);
//Part 1: Add large offsets to test a warning message that our clock may be wrong.
MultiAddTimeData(3, DEFAULT_MAX_TIME_ADJUSTMENT + 1);
// Filter size is 1 + 3 = 4: It is always initialized with a single element (offset 0)
noui_suppress();
MultiAddTimeData(1, DEFAULT_MAX_TIME_ADJUSTMENT + 1); //filter size 5
noui_reconnect();
BOOST_CHECK(GetWarnings("gui").find("clock is wrong") != std::string::npos);
// nTimeOffset is not changed if the median of offsets exceeds DEFAULT_MAX_TIME_ADJUSTMENT
BOOST_CHECK_EQUAL(GetTimeOffset(), 0);
// Part 2: Test positive and negative medians by adding more offsets
MultiAddTimeData(4, 100); // filter size 9
BOOST_CHECK_EQUAL(GetTimeOffset(), 100);
MultiAddTimeData(10, -100); //filter size 19
BOOST_CHECK_EQUAL(GetTimeOffset(), -100);
// Part 3: Test behaviour when filter has reached maximum number of offsets
const int MAX_SAMPLES = 200;
int nfill = (MAX_SAMPLES - 3 - 19) / 2; //89
MultiAddTimeData(nfill, 100);
MultiAddTimeData(nfill, -100); //filter size MAX_SAMPLES - 3
BOOST_CHECK_EQUAL(GetTimeOffset(), -100);
MultiAddTimeData(2, 100);
//filter size MAX_SAMPLES -1, median is the initial 0 offset
//since we added same number of positive/negative offsets
BOOST_CHECK_EQUAL(GetTimeOffset(), 0);
// After the number of offsets has reached MAX_SAMPLES -1 (=199), nTimeOffset will never change
// because it is only updated when the number of elements in the filter becomes odd. It was decided
// not to fix this because it prevents possible attacks. See the comment in AddTimeData() or issue #4521
// for a more detailed explanation.
MultiAddTimeData(2, 100); // filter median is 100 now, but nTimeOffset will not change
BOOST_CHECK_EQUAL(GetTimeOffset(), 0);
// We want this test to end with nTimeOffset==0, otherwise subsequent tests of the suite will fail.
}
BOOST_AUTO_TEST_SUITE_END()