void CheatEngine::addAddressesWithValue(const value_t& value, value_size_t size) {
assert(size > 0);
MEMORY_BASIC_INFORMATION info;
for (address_t address = nullptr;
VirtualQueryEx(m_process, address, &info, sizeof(info)) == sizeof(info);
address = static_cast<unsigned char*>(info.BaseAddress) + info.RegionSize) {
if (can_modify_page(info)) {
chunk_t chunk(info.RegionSize);
DWORD bytesRead;
ReadProcessMemory(m_process, address, chunk.data(), info.RegionSize, &bytesRead);
chunk.resize(bytesRead);
offsets_t matches;
for (chunk_t::size_type i = 0; i <= chunk.size() - size; ++i) {
if (std::equal(chunk.cbegin() + i, chunk.cbegin() + i + size, value.cbegin())) {
matches.push_back(i);
}
}
if (!matches.empty()) {
MemoryBlock block;
block.matches = matches;
block.baseAddress = info.BaseAddress;
block.size = bytesRead;
m_blocks.push_back(block);
}
}
}
}
void CheatEngine::keepAddressesWithValue(const value_t& value, value_size_t size) {
assert(!m_blocks.empty());
for (auto blockIt = begin(m_blocks); blockIt != end(m_blocks);) {
MEMORY_BASIC_INFORMATION info;
const auto len = VirtualQueryEx(m_process, blockIt->baseAddress, &info, sizeof(info));
assert(len == sizeof(info));
if (can_modify_page(info)) {
chunk_t chunk(blockIt->size);
DWORD bytesRead;
ReadProcessMemory(m_process, blockIt->baseAddress, chunk.data(), blockIt->size, &bytesRead);
chunk.resize(bytesRead);
blockIt->size = bytesRead;
// from the offsets that matched before within that page, only keep the ones that still match
offsets_t stillMatches;
for (auto offsetIt = blockIt->matches.cbegin(); offsetIt != blockIt->matches.cend(); ++offsetIt) {
assert(*offsetIt + size <= chunk.size());
if (std::equal(chunk.cbegin() + *offsetIt, chunk.cbegin() + *offsetIt + size, value.cbegin())) {
stillMatches.push_back(*offsetIt);
}
}
blockIt->matches = stillMatches;
// memory page no longer has matching addresses: drop it
if (blockIt->matches.empty()) {
blockIt = m_blocks.erase(blockIt);
}
else {
++blockIt;
}
}
else {
++blockIt;
}
}
}