Function readJSONStringInto

src/IO/ReadHelpers.cpp:831–867

template <typename Vector, typename ReturnType>
ReturnType readJSONStringInto(Vector & s, ReadBuffer & buf)
{
    static constexpr bool throw_exception = std::is_same_v<ReturnType, void>;

    auto error = [](const char * message [[maybe_unused]], int code [[maybe_unused]])
    {
        if constexpr (throw_exception)
            throw ParsingException(message, code);
        return ReturnType(false);
    };

    if (buf.eof() || *buf.position() != '"')
        return error("Cannot parse JSON string: expected opening quote", ErrorCodes::CANNOT_PARSE_QUOTED_STRING);
    ++buf.position();

    while (!buf.eof())
    {
        char * next_pos = find_first_symbols<'\\', '"'>(buf.position(), buf.buffer().end());

        appendToStringOrVector(s, buf, next_pos);
        buf.position() = next_pos;

        if (!buf.hasPendingData())
            continue;

        if (*buf.position() == '"')
        {
            ++buf.position();
            return ReturnType(true);
        }

        if (*buf.position() == '\\')
            parseJSONEscapeSequence<Vector, ReturnType>(s, buf);
    }

    return error("Cannot parse JSON string: expected closing quote", ErrorCodes::CANNOT_PARSE_QUOTED_STRING);
}

void readJSONString(String & s, ReadBuffer & buf)
{