Add unit test for UpdateCoins

This commit is contained in:
Alex Morcos 2015-11-11 20:36:16 -05:00
parent 03c82826f9
commit 1cf3dd80a6

View file

@ -6,6 +6,8 @@
#include "random.h"
#include "uint256.h"
#include "test/test_bitcoin.h"
#include "main.h"
#include "consensus/validation.h"
#include <vector>
#include <map>
@ -200,4 +202,133 @@ BOOST_AUTO_TEST_CASE(coins_cache_simulation_test)
BOOST_CHECK(missed_an_entry);
}
// This test is similar to the previous test
// except the emphasis is on testing the functionality of UpdateCoins
// random txs are created and UpdateCoins is used to update the cache stack
// In particular it is tested that spending a duplicate coinbase tx
// has the expected effect (the other duplicate is overwitten at all cache levels)
BOOST_AUTO_TEST_CASE(updatecoins_simulation_test)
{
bool spent_a_duplicate_coinbase = false;
// A simple map to track what we expect the cache stack to represent.
std::map<uint256, CCoins> result;
// The cache stack.
CCoinsViewTest base; // A CCoinsViewTest at the bottom.
std::vector<CCoinsViewCacheTest*> stack; // A stack of CCoinsViewCaches on top.
stack.push_back(new CCoinsViewCacheTest(&base)); // Start with one cache.
// Track the txids we've used and whether they have been spent or not
std::map<uint256, CAmount> coinbaseids;
std::set<uint256> alltxids;
std::set<uint256> duplicateids;
for (unsigned int i = 0; i < NUM_SIMULATION_ITERATIONS; i++) {
{
CMutableTransaction tx;
tx.vin.resize(1);
tx.vout.resize(1);
tx.vout[0].nValue = i; //Keep txs unique unless intended to duplicate
unsigned int height = insecure_rand();
// 1/10 times create a coinbase
if (insecure_rand() % 10 == 0 || coinbaseids.size() < 10) {
// 1/100 times create a duplicate coinbase
if (insecure_rand() % 10 == 0 && coinbaseids.size()) {
std::map<uint256, CAmount>::iterator coinbaseIt = coinbaseids.lower_bound(GetRandHash());
if (coinbaseIt == coinbaseids.end()) {
coinbaseIt = coinbaseids.begin();
}
//Use same random value to have same hash and be a true duplicate
tx.vout[0].nValue = coinbaseIt->second;
assert(tx.GetHash() == coinbaseIt->first);
duplicateids.insert(coinbaseIt->first);
}
else {
coinbaseids[tx.GetHash()] = tx.vout[0].nValue;
}
assert(CTransaction(tx).IsCoinBase());
}
// 9/10 times create a regular tx
else {
uint256 prevouthash;
// equally likely to spend coinbase or non coinbase
std::set<uint256>::iterator txIt = alltxids.lower_bound(GetRandHash());
if (txIt == alltxids.end()) {
txIt = alltxids.begin();
}
prevouthash = *txIt;
// Construct the tx to spend the coins of prevouthash
tx.vin[0].prevout.hash = prevouthash;
tx.vin[0].prevout.n = 0;
// Update the expected result of prevouthash to know these coins are spent
CCoins& oldcoins = result[prevouthash];
oldcoins.Clear();
// It is of particular importance here that once we spend a coinbase tx hash
// it is no longer available to be duplicated (or spent again)
// BIP 34 in conjunction with enforcing BIP 30 (at least until BIP 34 was active)
// results in the fact that no coinbases were duplicated after they were already spent
alltxids.erase(prevouthash);
coinbaseids.erase(prevouthash);
// The test is designed to ensure spending a duplicate coinbase will work properly
// if that ever happens and not resurrect the previously overwritten coinbase
if (duplicateids.count(prevouthash))
spent_a_duplicate_coinbase = true;
assert(!CTransaction(tx).IsCoinBase());
}
// Track this tx to possibly spend later
alltxids.insert(tx.GetHash());
// Update the expected result to know about the new output coins
CCoins &coins = result[tx.GetHash()];
coins.FromTx(tx, height);
CValidationState dummy;
UpdateCoins(tx, dummy, *(stack.back()), height);
}
// Once every 1000 iterations and at the end, verify the full cache.
if (insecure_rand() % 1000 == 1 || i == NUM_SIMULATION_ITERATIONS - 1) {
for (std::map<uint256, CCoins>::iterator it = result.begin(); it != result.end(); it++) {
const CCoins* coins = stack.back()->AccessCoins(it->first);
if (coins) {
BOOST_CHECK(*coins == it->second);
} else {
BOOST_CHECK(it->second.IsPruned());
}
}
}
if (insecure_rand() % 100 == 0) {
// Every 100 iterations, change the cache stack.
if (stack.size() > 0 && insecure_rand() % 2 == 0) {
stack.back()->Flush();
delete stack.back();
stack.pop_back();
}
if (stack.size() == 0 || (stack.size() < 4 && insecure_rand() % 2)) {
CCoinsView* tip = &base;
if (stack.size() > 0) {
tip = stack.back();
}
stack.push_back(new CCoinsViewCacheTest(tip));
}
}
}
// Clean up the stack.
while (stack.size() > 0) {
delete stack.back();
stack.pop_back();
}
// Verify coverage.
BOOST_CHECK(spent_a_duplicate_coinbase);
}
BOOST_AUTO_TEST_SUITE_END()