C++ AnyString::empty方法代码示例

	NodeType FetchFileStatus(const AnyString& filename, yuint64& size, yint64& lastModified, bool followSymLink)
	{
		size = 0u;
		lastModified = 0;
		return (YUNI_LIKELY(not filename.empty()))
			? Stat(filename, size, lastModified, followSymLink) : IO::typeUnknown;
	}

Cursor Transaction::prepare(const AnyString& stmt)
{
    assert(!(!pChannel));

    // the adapter
    ::yn_dbi_adapter& adapter = pChannel->adapter;

    if (YUNI_UNLIKELY(nullHandle == pTxHandle))
    {
        if (errNone != pChannel->begin(pTxHandle))
            return Cursor(adapter, nullptr);
    }

    // query handle
    void* handle = nullptr;

    if (YUNI_LIKELY(not stmt.empty() and adapter.dbh))
    {
        assert(adapter.query_new != NULL  and "invalid adapter query_new");
        assert(adapter.query_ref_acquire != NULL and "invalid adapter query_ref_acquire");
        assert(adapter.query_ref_release != NULL and "invalid adapter query_ref_release");

        adapter.query_new(&handle, adapter.dbh, stmt.c_str(), stmt.size());
    }

    return Cursor(adapter, handle);
}

	NodeType TypeOf(const AnyString& filename, bool followSymLink)
	{
		yuint64 size; // useless
		yint64 lastModified;
		return (YUNI_LIKELY(not filename.empty()))
			? Stat(filename, size, lastModified, followSymLink) : IO::typeUnknown;
	}

	File::File(const AnyString& filePath):
		pFormat(nullptr)
	{
		if (filePath.empty())
			return;

		# if LIBAVFORMAT_VERSION_MAJOR < 53
		if (::av_open_input_file(&pFormat, filePath.c_str(), nullptr, 0, nullptr))
		# else
		if (::avformat_open_input(&pFormat, filePath.c_str(), nullptr, nullptr))
		# endif // LIBAVFORMAT_VERSION_MAJOR < 53
		{
			pFormat = nullptr;
			return;
		}

		// After opening, we must search for the stream information because not
		// all formats will have it in stream headers (eg. system MPEG streams)
		# if LIBAVFORMAT_VERSION_MAJOR < 53
		if (::av_find_stream_info(pFormat) < 0)
		# else
		if (::avformat_find_stream_info(pFormat, nullptr) < 0)
		# endif // LIBAVFORMAT_VERSION_MAJOR < 53
		{
			# if LIBAVFORMAT_VERSION_MAJOR < 53
			::av_close_input_file(pFormat);
			# else
			::avformat_close_input(&pFormat);
			# endif // LIBAVFORMAT_VERSION_MAJOR < 53
			pFormat = nullptr;
			return;
		}
	}

	bool Size(const AnyString& filename, uint64& value)
	{
		struct stat results;
		if (not filename.empty() && stat(filename.c_str(), &results) == 0)
		{
			value = (uint64) results.st_size;
			return true;
		}
		value = 0u;
		return false;
	}

	Yuni::IO::NodeType TypeOf(const AnyString& filename)
	{
		if (filename.empty())
			return Yuni::IO::typeUnknown;

		# ifdef YUNI_OS_WINDOWS
		const char* p = filename.c_str();
		unsigned int len = filename.size();
		if (p[len - 1] == '\\' or p[len - 1] == '/')
		{
			if (!--len)
			{
				# ifdef YUNI_OS_WINDOWS
				return Yuni::IO::typeUnknown;
				# else
				// On Unixes, `/` is a valid folder
				return Yuni::IO::typeFolder;
				# endif
			}
		}

		// Driver letters
		if (len == 2 and p[1] == ':')
			return Yuni::IO::typeFolder;

		String  norm;
		Yuni::IO::Normalize(norm, AnyString(p, len));
		// Conversion into wchar_t
		Private::WString<true> wstr(norm);
		if (wstr.empty())
			return Yuni::IO::typeUnknown;

		WIN32_FILE_ATTRIBUTE_DATA infoFile;
		if (!GetFileAttributesExW(wstr.c_str(), GetFileExInfoStandard, &infoFile))
			return Yuni::IO::typeUnknown;

		return ((infoFile.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0)
			? Yuni::IO::typeFolder
			: Yuni::IO::typeFile;

		# else // WINDOWS

		struct stat s;
		if (stat(filename.c_str(), &s) != 0)
			return Yuni::IO::typeUnknown;

		return (S_ISDIR(s.st_mode))
			? Yuni::IO::typeFolder
			: Yuni::IO::typeFile;
		# endif
	}

	bool Create(const AnyString& path, uint mode)
	{
		if (not path.empty() and not Yuni::IO::Exists(path))
		{
			# ifdef YUNI_OS_WINDOWS
			// `mode` is not used on Windows
			(void) mode;
			return WindowsMake(path);
			# else
			return UnixMake(path, mode);
			# endif
		}
		return true;
	}

	Yuni::IO::Error Delete(const AnyString& filename)
	{
		// DeleteFile is actually a macro and will be replaced by DeleteFileW
		// with Visual Studio. Consequently we can not use the word DeleteFile.....

		if (filename.empty())
			return Yuni::IO::errUnknown;

		# ifndef YUNI_OS_WINDOWS

		return (unlink(filename.c_str()))
			? Yuni::IO::errUnknown
			: Yuni::IO::errNone;

		# else

		const char* const p = filename.c_str();
		uint len = filename.size();

		if (p[len - 1] == '\\' or p[len - 1] == '/')
			--len;

		// Driver letters
		if (len == 2 and p[1] == ':')
			return Yuni::IO::errBadFilename;

		String norm;
		Yuni::IO::Normalize(norm, AnyString(p, len));

		// Conversion into wchar_t
		WString wstr(norm, true);
		if (wstr.empty())
			return Yuni::IO::errUnknown;
		wstr.replace('/', '\\');

		return (DeleteFileW(wstr.c_str()))
			? Yuni::IO::errNone
			: Yuni::IO::errUnknown;
		# endif
	}

	static bool DecodeURLQuery(KeyValueStore& params, const AnyString& query)
	{
		// note: mongoose does not provide the fragment here, so we don't have
		// to check it

		// Some tests are already done before calling this method
		assert(not query.empty());

		String key; // temporary string for parameters handling
		uint offset = 0;
		uint start = 0;
		AnyString value;
		do
		{
			offset = query.find_first_of("=&", offset);
			if (offset >= query.size())
			{
				// ignoring fields with empty value (using default)
				break;
			}
			if (query[offset] == '=')
			{
				key.assign(query, offset - start, start);
				if (key.empty()) // malformed url. aborting
					return false;

				++offset;

				// FIXME !!!! & are not properly handled !!!!!!!!!!!!
				uint ampersand = offset;
				ampersand = query.find('&', ampersand);
				if (ampersand >= query.size())
				{
					value.adapt(query, query.size() - offset, offset);
					ampersand = query.size();
				}
				else
					value.adapt(query, ampersand - offset, offset);

				if (not value.empty())
				{
					KeyValueStore::iterator i = params.find(key);
					if (i != params.end())
					{
						// the item has been found !
						params[key] = value;
					}
				}

				offset = ampersand;
			}
			else
			{
				// ignoring fields with empty value (using default)
			}

			// updating offsets
			start = ++offset;
		}
		while (true);
		return true;
	}

	void Program::commandLine(AnyString cmd)
	{
		// remove all whitespaces
		cmd.trim();

		auto envptr = pEnv; // keeping a reference to the current env
		if (!envptr)
		{
			envptr = std::make_shared<ProcessSharedInfo>();
			pEnv = envptr;
		}
		ProcessSharedInfo& env = *envptr;

		MutexLocker locker(env.mutex);
		env.executable.clear();
		env.arguments.clear();

		if (cmd.empty())
			return;


		String* str = &env.executable;
		char instring = '\0';
		const AnyString::null_iterator end = cmd.utf8end();
		for (AnyString::const_utf8iterator i = cmd.utf8begin(); i != end; ++i)
		{
			char c = *i;
			switch (c)
			{
				default:
				{
					*str += i.value();
					break;
				}
				case '"':
					[[fallthrough]];
				case '\'':
				{
					if (instring == '\0')
					{
						instring = c;
					}
					else
					{
						if (instring == c)
							instring = '\0';
						else
							*str += c;
					}
					break;
				}
				case '\\':
				{
					++i;
					if (YUNI_UNLIKELY(i == end))
						return;
					c = *i;
					switch (c)
					{
						case 'n':  (*str) += '\n'; break;
						case 't':  (*str) += '\t'; break;
						case 'r':  (*str) += '\r'; break;
						case 'b':  (*str) += '\b'; break;
						case 'f':  (*str) += '\f'; break;
						case 'v':  (*str) += '\v'; break;
						case '0':  (*str) += '\0'; break;
						case 'e': [[fallthrough]];
						case 'a': [[fallthrough]];
						case 'E':  break;
						default:   (*str) << '\\' << c; break;
					}
					break;
				}
				case ' ':
					[[fallthrough]];
				case '\t':
				{
					if (instring == '\0')
					{
						if (not str->empty())
						{
							env.arguments.push_back(nullptr);
							str = &(env.arguments.back());
						}
					}
					else
						*str += c;
					break;
				}
			}
		}
	}

	void WString::prepareWString(const AnyString& string, bool uncprefix)
	{
		if (string.empty())
		{
			if (uncprefix)
			{
				pSize = 4;
				pWString = (wchar_t*)::realloc(pWString, sizeof(wchar_t) * 5);
				pWString[0] = L'\\';
				pWString[1] = L'\\';
				pWString[2] = L'?';
				pWString[3] = L'\\';
				pWString[4] = L'\0';
			}
			else
				clear();
			return;
		}

		if (string.size() > INT_MAX)
		{
			clear();
			return;
		}

		// Offset according to the presence of the UNC prefix
		const uint offset = (not uncprefix) ? 0 : 4;

		#ifdef YUNI_OS_WINDOWS
		{
			// Allocate and convert the C-String. Several iterations may be required
			// for allocating enough room for the conversion.
			const int sizeRequired = MultiByteToWideChar(CP_UTF8, 0, string.c_str(), string.size(), nullptr, 0);
			if (sizeRequired <= 0)
			{
				clear();
				return;
			}

			pSize = sizeRequired + offset;

			pWString = (wchar_t*) realloc(pWString, sizeof(wchar_t) * (pSize + 1));
			if (nullptr == pWString) // Impossible to allocate the buffer. Aborting.
			{
				clear();
				return;
			}

			// Converting into Wide String
			const int n = MultiByteToWideChar(CP_UTF8, 0, string.c_str(), static_cast<int>(string.size()), pWString + offset, static_cast<int>(pSize - offset));
			if (n != sizeRequired)
			{
				assert(false and "most likely an error");
				clear();
				return;
			}
		}
		#else
		{
			const char* wcstr = string.c_str();

			mbstate_t state;
			memset (&state, '\0', sizeof (state));

			size_t sizeRequired = mbsnrtowcs(nullptr, &wcstr, string.size(), 0, &state);
			if (0 == sizeRequired or (size_t) -1 == sizeRequired)
			{
				clear();
				return;
			}

			pSize = sizeRequired + offset;

			pWString = (wchar_t*) realloc(pWString, sizeof(wchar_t) * (pSize + 1));
			if (nullptr == pWString) // Impossible to allocate the buffer. Aborting.
			{
				clear();
				return;
			}

			memset (&state, '\0', sizeof (state));
			size_t written = mbsnrtowcs(pWString + offset, &wcstr, string.size(), pSize - offset, &state);
			if (0 == written or (size_t) -1 == written)
			{
				clear();
				return;
			}
		}
		#endif


		// prepend the Windows UNC prefix
		if (uncprefix)
		{
			pWString[0] = L'\\';
			pWString[1] = L'\\';
			pWString[2] = L'?';
			pWString[3] = L'\\';
		}

//.........这里部分代码省略.........

	bool Resize(const AnyString& filename, uint64_t size)
	{
		if (not filename.empty())
		{
			if (size < std::numeric_limits<off_t>::max())
			{
				#ifndef YUNI_OS_WINDOWS
				{
					assert((filename.c_str())[filename.size()] == '\0');
					#ifdef YUNI_OS_MAC
					int fd = open(filename.c_str(), O_WRONLY|O_CREAT, 0644);
					#else
					int fd = open(filename.c_str(), O_WRONLY|O_CREAT|O_LARGEFILE, 0644);
					#endif
					if (fd != -1)
					{
						bool success = (0 == ftruncate(fd, static_cast<off_t>(size)));
						close(fd);
						return success;
					}
				}
				#else
				{
					WString wstr(filename, true);
					if (not wstr.empty())
					{
						HANDLE hndl = CreateFileW(wstr.c_str(), GENERIC_WRITE, FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
						if (hndl)
						{
							LARGE_INTEGER li;
							li.QuadPart = size;
							DWORD dwPtr = SetFilePointer(hndl, li.LowPart, &li.HighPart, FILE_BEGIN);
							if (dwPtr != INVALID_SET_FILE_POINTER)
								SetEndOfFile(hndl);
							CloseHandle(hndl);
							return true;
						}
					}
				}
				#endif
			}
		}
		return false;
	}