neobytes/src/test/coins_tests.cpp
2015-11-12 09:55:12 -05:00

335 lines
12 KiB
C++

// Copyright (c) 2014 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "coins.h"
#include "random.h"
#include "uint256.h"
#include "test/test_bitcoin.h"
#include "main.h"
#include "consensus/validation.h"
#include <vector>
#include <map>
#include <boost/test/unit_test.hpp>
namespace
{
class CCoinsViewTest : public CCoinsView
{
uint256 hashBestBlock_;
std::map<uint256, CCoins> map_;
public:
bool GetCoins(const uint256& txid, CCoins& coins) const
{
std::map<uint256, CCoins>::const_iterator it = map_.find(txid);
if (it == map_.end()) {
return false;
}
coins = it->second;
if (coins.IsPruned() && insecure_rand() % 2 == 0) {
// Randomly return false in case of an empty entry.
return false;
}
return true;
}
bool HaveCoins(const uint256& txid) const
{
CCoins coins;
return GetCoins(txid, coins);
}
uint256 GetBestBlock() const { return hashBestBlock_; }
bool BatchWrite(CCoinsMap& mapCoins, const uint256& hashBlock)
{
for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end(); ) {
if (it->second.flags & CCoinsCacheEntry::DIRTY) {
// Same optimization used in CCoinsViewDB is to only write dirty entries.
map_[it->first] = it->second.coins;
if (it->second.coins.IsPruned() && insecure_rand() % 3 == 0) {
// Randomly delete empty entries on write.
map_.erase(it->first);
}
}
mapCoins.erase(it++);
}
if (!hashBlock.IsNull())
hashBestBlock_ = hashBlock;
return true;
}
bool GetStats(CCoinsStats& stats) const { return false; }
};
class CCoinsViewCacheTest : public CCoinsViewCache
{
public:
CCoinsViewCacheTest(CCoinsView* base) : CCoinsViewCache(base) {}
void SelfTest() const
{
// Manually recompute the dynamic usage of the whole data, and compare it.
size_t ret = memusage::DynamicUsage(cacheCoins);
for (CCoinsMap::iterator it = cacheCoins.begin(); it != cacheCoins.end(); it++) {
ret += it->second.coins.DynamicMemoryUsage();
}
BOOST_CHECK_EQUAL(DynamicMemoryUsage(), ret);
}
};
}
BOOST_FIXTURE_TEST_SUITE(coins_tests, BasicTestingSetup)
static const unsigned int NUM_SIMULATION_ITERATIONS = 40000;
// This is a large randomized insert/remove simulation test on a variable-size
// stack of caches on top of CCoinsViewTest.
//
// It will randomly create/update/delete CCoins entries to a tip of caches, with
// txids picked from a limited list of random 256-bit hashes. Occasionally, a
// new tip is added to the stack of caches, or the tip is flushed and removed.
//
// During the process, booleans are kept to make sure that the randomized
// operation hits all branches.
BOOST_AUTO_TEST_CASE(coins_cache_simulation_test)
{
// Various coverage trackers.
bool removed_all_caches = false;
bool reached_4_caches = false;
bool added_an_entry = false;
bool removed_an_entry = false;
bool updated_an_entry = false;
bool found_an_entry = false;
bool missed_an_entry = 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.
// Use a limited set of random transaction ids, so we do test overwriting entries.
std::vector<uint256> txids;
txids.resize(NUM_SIMULATION_ITERATIONS / 8);
for (unsigned int i = 0; i < txids.size(); i++) {
txids[i] = GetRandHash();
}
for (unsigned int i = 0; i < NUM_SIMULATION_ITERATIONS; i++) {
// Do a random modification.
{
uint256 txid = txids[insecure_rand() % txids.size()]; // txid we're going to modify in this iteration.
CCoins& coins = result[txid];
CCoinsModifier entry = stack.back()->ModifyCoins(txid);
BOOST_CHECK(coins == *entry);
if (insecure_rand() % 5 == 0 || coins.IsPruned()) {
if (coins.IsPruned()) {
added_an_entry = true;
} else {
updated_an_entry = true;
}
coins.nVersion = insecure_rand();
coins.vout.resize(1);
coins.vout[0].nValue = insecure_rand();
*entry = coins;
} else {
coins.Clear();
entry->Clear();
removed_an_entry = true;
}
}
// 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);
found_an_entry = true;
} else {
BOOST_CHECK(it->second.IsPruned());
missed_an_entry = true;
}
}
BOOST_FOREACH(const CCoinsViewCacheTest *test, stack) {
test->SelfTest();
}
}
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();
} else {
removed_all_caches = true;
}
stack.push_back(new CCoinsViewCacheTest(tip));
if (stack.size() == 4) {
reached_4_caches = true;
}
}
}
}
// Clean up the stack.
while (stack.size() > 0) {
delete stack.back();
stack.pop_back();
}
// Verify coverage.
BOOST_CHECK(removed_all_caches);
BOOST_CHECK(reached_4_caches);
BOOST_CHECK(added_an_entry);
BOOST_CHECK(removed_an_entry);
BOOST_CHECK(updated_an_entry);
BOOST_CHECK(found_an_entry);
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()