#include #include #include #include #include #include #include #include namespace DB { namespace ErrorCodes { extern const int TOO_DEEP_RECURSION; extern const int DIRECTORY_ALREADY_EXISTS; } static void localBackupImpl(const Poco::Path & source_path, const Poco::Path & destination_path, size_t level, std::optional max_level) { if (max_level && level > *max_level) return; if (level >= 1000) throw DB::Exception("Too deep recursion", DB::ErrorCodes::TOO_DEEP_RECURSION); Poco::File(destination_path).createDirectories(); Poco::DirectoryIterator dir_end; for (Poco::DirectoryIterator dir_it(source_path); dir_it != dir_end; ++dir_it) { Poco::Path source = dir_it.path(); Poco::Path destination = destination_path; destination.append(dir_it.name()); if (!dir_it->isDirectory()) { dir_it->setReadOnly(); createHardLink(source.toString(), destination.toString()); } else { localBackupImpl(source, destination, level + 1, max_level); } } } void localBackup(const Poco::Path & source_path, const Poco::Path & destination_path, std::optional max_level) { if (Poco::File(destination_path).exists() && Poco::DirectoryIterator(destination_path) != Poco::DirectoryIterator()) { throw DB::Exception("Directory " + destination_path.toString() + " already exists and is not empty.", DB::ErrorCodes::DIRECTORY_ALREADY_EXISTS); } size_t try_no = 0; const size_t max_tries = 10; /** Files in the directory can be permanently added and deleted. * If some file is deleted during an attempt to make a backup, then try again, * because it's important to take into account any new files that might appear. */ while (true) { try { localBackupImpl(source_path, destination_path, 0, max_level); } catch (const DB::ErrnoException & e) { if (e.getErrno() != ENOENT) throw; ++try_no; if (try_no == max_tries) throw; continue; } catch (const Poco::FileNotFoundException &) { ++try_no; if (try_no == max_tries) throw; continue; } break; } } }