C++ string_view::data方法代码示例

vector<int> readIntegerFile(string_view fileName)
{
	ifstream inputStream(fileName.data());
	if (inputStream.fail()) {
		// We failed to open the file: throw an exception
		const string error = "Unable to open file "s + fileName.data();
		throw invalid_argument(error);
	}

	// Read the integers one-by-one and add them to a vector
	vector<int> integers;
	int temp;
	while (inputStream >> temp) {
		integers.push_back(temp);
	}

	if (!inputStream.eof()) {
		// We did not reach the end-of-file.
		// This means that some error occurred while reading the file.
		// Throw an exception.
		const string error = "Unable to read file "s + fileName.data();
		throw runtime_error(error);
	}

	return integers;
}

	bdecode_node bdecode_node::dict_find(string_view key) const
	{
		TORRENT_ASSERT(type() == dict_t);

		bdecode_token const* tokens = m_root_tokens;

		// this is the first item
		int token = m_token_idx + 1;

		while (tokens[token].type != bdecode_token::end)
		{
			bdecode_token const& t = tokens[token];
			TORRENT_ASSERT(t.type == bdecode_token::string);
			int const size = m_root_tokens[token + 1].offset - t.offset - t.start_offset();
			if (int(key.size()) == size
				&& std::equal(key.data(), key.data() + size, m_buffer
					+ t.offset + t.start_offset()))
			{
				// skip key
				token += t.next_item;
				TORRENT_ASSERT(tokens[token].type != bdecode_token::end);

				return bdecode_node(tokens, m_buffer, m_buffer_size, token);
			}

			// skip key
			token += t.next_item;
			TORRENT_ASSERT(tokens[token].type != bdecode_token::end);

			// skip value
			token += tokens[token].next_item;
		}

		return bdecode_node();
	}

    int reload(lua_State* L, const Data& chunk, const string_view& name)
    {
        lua_getglobal(L, "package");
        lua_pushliteral(L, "loaded");
        lua_rawget(L, -2);

        R_ASSERT(lua_istable(L, -1), "Missing control table 'package.loaded'");

        lua_pushlstring(L, name.data(), name.length());
        lua_pushnil(L);
        lua_rawset(L, -3);
        lua_pop(L, 2);
        return load(L, chunk, name.data(), true);
    }

	// returns the unicode codepoint and the number of bytes of the utf8 sequence
	// that was parsed. The codepoint is -1 if it's invalid
	std::pair<std::int32_t, int> parse_utf8_codepoint(string_view str)
	{
		int const sequence_len = trailingBytesForUTF8[static_cast<std::uint8_t>(str[0])] + 1;
		if (sequence_len > int(str.size())) return std::make_pair(-1, static_cast<int>(str.size()));

		if (sequence_len > 4)
		{
			return std::make_pair(-1, sequence_len);
		}

		if (!isLegalUTF8(reinterpret_cast<UTF8 const*>(str.data()), sequence_len))
		{
			return std::make_pair(-1, sequence_len);
		}

		std::uint32_t ch = 0;
		for (int i = 0; i < sequence_len; ++i)
		{
			ch <<= 6;
			ch += static_cast<std::uint8_t>(str[static_cast<std::size_t>(i)]);
		}
		ch -= offsetsFromUTF8[sequence_len-1];

		if (ch > 0x7fffffff)
		{
			return std::make_pair(-1, sequence_len);
		}

		return std::make_pair(static_cast<std::int32_t>(ch), sequence_len);
	}

void stdLogger(int level, string_view msg) noexcept
{
  const auto now = UnixClock::now();
  const auto t = UnixClock::to_time_t(now);
  const auto ms = timeToMs(now);

  struct tm tm;
  localtime_r(&t, &tm);

  // The following format has an upper-bound of 42 characters:
  // "%b %d %H:%M:%S.%03d %-7s [%d]: "
  //
  // Example:
  // Mar 14 00:00:00.000 WARNING [0123456789]: msg...
  // <---------------------------------------->
  char head[42 + 1];
  size_t hlen = strftime(head, sizeof(head), "%b %d %H:%M:%S", &tm);
  hlen += sprintf(head + hlen, ".%03d %-7s [%d]: ", static_cast<int>(ms % 1000), logLabel(level),
                  static_cast<int>(getpid()));
  char tail = '\n';
  iovec iov[] = {
    {head, hlen}, //
    {const_cast<char*>(msg.data()), msg.size()}, //
    {&tail, 1} //
  };

  int fd{level > LogWarning ? STDOUT_FILENO : STDERR_FILENO};
// Best effort given that this is the logger.
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-result"
  writev(fd, iov, sizeof(iov) / sizeof(iov[0]));
#pragma GCC diagnostic pop
}

void test_strview_basics(const string_view& sv, const char *p, size_t n) {
    ASSERT_EQ(p, sv.data());
    ASSERT_EQ(n, sv.size());
    ASSERT_EQ(n, sv.length());
    ASSERT_EQ((n == 0), sv.empty());

    ASSERT_EQ(p, sv.cbegin());
    ASSERT_EQ(p, sv.begin());
    ASSERT_EQ(p + n, sv.cend());
    ASSERT_EQ(p + n, sv.end());

    using reviter_t = std::reverse_iterator<string_view::const_iterator>;

    ASSERT_EQ(reviter_t(sv.end()),    sv.rbegin());
    ASSERT_EQ(reviter_t(sv.begin()),  sv.rend());
    ASSERT_EQ(reviter_t(sv.cend()),   sv.crbegin());
    ASSERT_EQ(reviter_t(sv.cbegin()), sv.crend());

    for (size_t i = 0; i < n; ++i) {
        ASSERT_EQ(p[i], sv[i]);
        ASSERT_EQ(p[i], sv.at(i));
    }
    ASSERT_THROW(sv.at(n), std::out_of_range);
    ASSERT_THROW(sv.at(string_view::npos), std::out_of_range);

    if (n > 0) {
        ASSERT_EQ(p,         &(sv.front()));
        ASSERT_EQ(p + (n-1), &(sv.back()));
        ASSERT_EQ(p[0],        sv.front());
        ASSERT_EQ(p[n-1],      sv.back());
    }
}

void
write_buffer(DynamicBuffer& b, string_view s)
{
    b.commit(boost::asio::buffer_copy(
        b.prepare(s.size()), boost::asio::buffer(
            s.data(), s.size())));
}

Exception::Exception(string_view what) noexcept
{
    const auto len = min(what.size(), MaxErrMsg);
    if (len > 0) {
        memcpy(what_, what.data(), len);
    }
    what_[len] = '\0';
}

	allocation_slot stack_allocator::copy_string(string_view str)
	{
		int const ret = int(m_storage.size());
		m_storage.resize(ret + numeric_cast<int>(str.size()) + 1);
		std::memcpy(&m_storage[ret], str.data(), str.size());
		m_storage[ret + int(str.length())] = '\0';
		return allocation_slot(ret);
	}

path_match_result path_match(string_view input, string_view& match_contents)
{
    if (input.length() < 2)
        return path_match_result::invalid;
    
    match_result result;
    token_kind kind;
    std::size_t length;
    
    switch (input.at(0))
    {
    case '.':
        result = match_simple_string(input.data() + 1, input.data() + input.size(), kind, length);
        if (result == match_result::complete)
        {
            match_contents = input.substr(0, length + 1);
            return path_match_result::simple_object;
        }
        else
        {
            return path_match_result::invalid;
        }
    case '[':
        result = attempt_match(input.data() + 1, input.data() + input.length(), kind, length);
        if (result == match_result::complete)
        {
            if (input.length() == length + 1 || input.at(1 + length) != ']')
                return path_match_result::invalid;
            if (kind != token_kind::string && kind != token_kind::number)
                return path_match_result::invalid;
            
            match_contents = input.substr(0, length + 2);
            return path_match_result::brace;
        }
        else
        {
            return path_match_result::invalid;
        }
    default:
        return path_match_result::invalid;
    }
}

	std::wstring utf8_wchar(string_view utf8, error_code& ec)
	{
		// allocate space for worst-case
		std::wstring wide;
		wide.resize(utf8.size());
		char const* src_start = utf8.data();
		utf8_errors::error_code_enum const ret = convert_to_wide<sizeof(wchar_t)>::convert(
			&src_start, src_start + utf8.size(), wide);
		if (ret != utf8_errors::error_code_enum::conversion_ok)
			ec = make_error_code(ret);
		return wide;
	}

void ArticleCitations::readFile(string_view fileName)
{
	// Open the file and check for failure.
	ifstream inputFile(fileName.data());
	if (inputFile.fail()) {
		throw invalid_argument("Unable to open file");
	}
	// Read the article author, title, etc. line.
	getline(inputFile, mArticle);

	// Skip the white space before the citations start.
	inputFile >> ws;

	int count = 0;
	// Save the current position so we can return to it.
	streampos citationsStart = inputFile.tellg();
	// First count the number of citations.
	cout << "readFile(): counting number of citations" << endl;
	while (!inputFile.eof()) {
		// Skip white space before the next entry.
		inputFile >> ws;
		string temp;
		getline(inputFile, temp);
		if (!temp.empty()) {
			cout << "Citation " << count << ": " << temp << endl;
			count++;
		}
	}

	cout << "Found " << count << " citations" << endl;
	cout << "readFile(): reading citations" << endl;
	if (count != 0) {
		// Allocate an array of strings to store the citations.
		mCitations = new string[count];
		mNumCitations = count;
		// Seek back to the start of the citations.
		inputFile.seekg(citationsStart);
		// Read each citation and store it in the new array.
		for (count = 0; count < mNumCitations; count++) {
			string temp;
			getline(inputFile, temp);
			if (!temp.empty()) {
				cout << temp << endl;
				mCitations[count] = temp;
			}
		}
	} else {
		mNumCitations = -1;
	}

	cout << "readFile(): finished" << endl;
}

// -----------------------------------------------------------------------------
// Shows the splash window with [message].
// If [progress] is true, the progress bar is displayed
// -----------------------------------------------------------------------------
void UI::showSplash(string_view message, bool progress, wxWindow* parent)
{
	if (!splash_enabled || !isMainThread())
		return;

	if (!splash_window)
	{
		SplashWindow::init();
		splash_window = std::make_unique<SplashWindow>();
	}

	splash_window->show(wxString{ message.data(), message.size() }, progress, parent);
}

vector<int> readIntegerFile(string_view fileName)
{
	ifstream inputStream(fileName.data());
	if (inputStream.fail()) {
		// We failed to open the file: throw an exception
		throw exception();
	}

	// Read the integers one-by-one and add them to a vector
	vector<int> integers;
	int temp;
	while (inputStream >> temp) {
		integers.push_back(temp);
	}
	return integers;
}

//===========================================================================
Count::Count(string_view path) {
    auto * base = path.data();
    auto * ptr = base;
    auto * eptr = ptr + path.size();
    char const * colon = nullptr;    // first ':'
    char const * slash = nullptr;    // last '/' or '\'
    char const * dot = nullptr;      // last '.'
    for (; ptr != eptr; ++ptr) {
        switch(*ptr) {
        case '.':
            dot = ptr;
            break;
        case '/':
        case '\\':
            slash = ptr;
            break;
        case ':':
            if (!colon)
                colon = ptr;
            break;
        }
    }

    if (!slash) {
        m_rootLen = colon ? unsigned(colon - base + 1) : 0;
        m_dirLen = 0;
    } else {
        m_rootLen = (colon && colon < slash) ? unsigned(colon - base + 1) : 0;
        m_dirLen = unsigned(slash - base + 1 - m_rootLen);
    }
    if (!dot || unsigned(dot - base) <= m_rootLen + m_dirLen) {
        m_stemLen = unsigned(path.size() - m_rootLen - m_dirLen);
        m_extLen = 0;
    } else {
        m_stemLen = unsigned(dot - base - m_rootLen - m_dirLen);
        m_extLen = unsigned(eptr - dot);
        if (m_extLen == 1 && m_stemLen == 1 && dot[-1] == '.') {
            m_stemLen = 2;
            m_extLen = 0;
        } else if (!m_stemLen) {
            m_stemLen = m_extLen;
            m_extLen = 0;
        }
    }
    assert(m_extLen == path.size() - m_rootLen - m_dirLen - m_stemLen);
}