Method SaveHashSet

src/SHAHashSet.cpp:695–773

bool CAICHHashSet::SaveHashSet()
{
	if (m_eStatus != AICH_HASHSETCOMPLETE) {
		wxFAIL;
		return false;
	}
	if ( !m_pHashTree.m_bHashValid || m_pHashTree.m_nDataSize != m_pOwner->GetFileSize()) {
		wxFAIL;
		return false;
	}

	wxMutexLocker cacheLock(s_rootHashCacheMutex);

	if (!s_rootHashCacheLoaded) {
		LoadRootHashCacheLocked();
	}

	// O(1) dedup — replaces the linear file walk that used to make this
	// O(N) per call and O(N^2) over a bulk-hashing batch.
	if (s_rootHashCache.find(m_pHashTree.m_Hash) != s_rootHashCache.end()) {
		return true;
	}

	try {
		const wxString fullpath = thePrefs::GetConfigDir() + KNOWN2_MET_FILENAME;
		const bool exists = wxFile::Exists(fullpath);

		CFile file(fullpath, exists ? CFile::read_write : CFile::write);
		if (!file.IsOpened()) {
			AddDebugLogLineC(logSHAHashSet, "Failed to save HashSet: opening met file failed!");
			return false;
		}

		uint64 nExistingSize = file.GetLength();
		if (nExistingSize) {
			uint8 header = file.ReadUInt8();
			if (header != KNOWN2_MET_VERSION) {
				AddDebugLogLineC(logSHAHashSet, "Saving failed: Current file is not a met-file!");
				return false;
			}
			// Skip the in-file dedup walk; the cache already confirmed
			// our root hash isn't present.
			file.Seek(static_cast<wxFileOffset>(nExistingSize), wxFromStart);
		} else {
			file.WriteUInt8(KNOWN2_MET_VERSION);
			// Update the recorded size, in order for the sanity check below to work.
			nExistingSize += 1;
		}

		// write hashset
		m_pHashTree.m_Hash.Write(&file);
		uint32 nHashCount = (PARTSIZE/EMBLOCKSIZE + ((PARTSIZE % EMBLOCKSIZE != 0)? 1 : 0)) * (m_pHashTree.m_nDataSize/PARTSIZE);
		if (m_pHashTree.m_nDataSize % PARTSIZE != 0) {
			nHashCount += (m_pHashTree.m_nDataSize % PARTSIZE)/EMBLOCKSIZE + (((m_pHashTree.m_nDataSize % PARTSIZE) % EMBLOCKSIZE != 0)? 1 : 0);
		}
		file.WriteUInt32(nHashCount);
		if (!m_pHashTree.WriteLowestLevelHashs(&file, 0, true, true)) {
			// that's bad... really