From a3473fda6acae16682a10051c1f092e039c19826 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Th=C3=A9o=20DELRIEU?= Date: Mon, 14 Aug 2017 18:04:51 +0200 Subject: [PATCH] add detail/serializer.hpp --- Makefile | 3 +- src/detail/serializer.hpp | 794 ++++++++++++++++++++++++++++++++++++++ src/json.hpp | 769 +----------------------------------- 3 files changed, 797 insertions(+), 769 deletions(-) create mode 100644 src/detail/serializer.hpp diff --git a/Makefile b/Makefile index 928f37d8..b646081d 100644 --- a/Makefile +++ b/Makefile @@ -20,7 +20,8 @@ SRCS = ${SRCDIR}/json.hpp \ ${SRCDIR}/detail/iterators/json_reverse_iterator.hpp \ ${SRCDIR}/detail/parsing/output_adapters.hpp \ ${SRCDIR}/detail/parsing/binary_reader.hpp \ - ${SRCDIR}/detail/parsing/binary_writer.hpp + ${SRCDIR}/detail/parsing/binary_writer.hpp \ + ${SRCDIR}/detail/serializer.hpp # main target all: diff --git a/src/detail/serializer.hpp b/src/detail/serializer.hpp new file mode 100644 index 00000000..955a3eac --- /dev/null +++ b/src/detail/serializer.hpp @@ -0,0 +1,794 @@ +#ifndef NLOHMANN_JSON_DETAIL_SERIALIZER_HPP +#define NLOHMANN_JSON_DETAIL_SERIALIZER_HPP + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "detail/macro_scope.hpp" +#include "detail/meta.hpp" +#include "detail/parsing/output_adapters.hpp" + +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// serialization // +/////////////////// + +template +class serializer +{ + using string_t = typename BasicJsonType::string_t; + using number_float_t = typename BasicJsonType::number_float_t; + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + public: + /*! + @param[in] s output stream to serialize to + @param[in] ichar indentation character to use + */ + serializer(output_adapter_t s, const char ichar) + : o(std::move(s)), loc(std::localeconv()), + thousands_sep(loc->thousands_sep == nullptr ? '\0' : * (loc->thousands_sep)), + decimal_point(loc->decimal_point == nullptr ? '\0' : * (loc->decimal_point)), + indent_char(ichar), indent_string(512, indent_char) {} + + // delete because of pointer members + serializer(const serializer&) = delete; + serializer& operator=(const serializer&) = delete; + + /*! + @brief internal implementation of the serialization function + + This function is called by the public member function dump and organizes + the serialization internally. The indentation level is propagated as + additional parameter. In case of arrays and objects, the function is + called recursively. + + - strings and object keys are escaped using `escape_string()` + - integer numbers are converted implicitly via `operator<<` + - floating-point numbers are converted to a string using `"%g"` format + + @param[in] val value to serialize + @param[in] pretty_print whether the output shall be pretty-printed + @param[in] indent_step the indent level + @param[in] current_indent the current indent level (only used internally) + */ + void dump(const BasicJsonType& val, const bool pretty_print, + const bool ensure_ascii, + const unsigned int indent_step, + const unsigned int current_indent = 0) + { + switch (val.m_type) + { + case value_t::object: + { + if (val.m_value.object->empty()) + { + o->write_characters("{}", 2); + return; + } + + if (pretty_print) + { + o->write_characters("{\n", 2); + + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } + + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\": ", 3); + dump(i->second, true, ensure_ascii, indent_step, new_indent); + o->write_characters(",\n", 2); + } + + // last element + assert(i != val.m_value.object->cend()); + assert(std::next(i) == val.m_value.object->cend()); + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\": ", 3); + dump(i->second, true, ensure_ascii, indent_step, new_indent); + + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character('}'); + } + else + { + o->write_character('{'); + + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\":", 2); + dump(i->second, false, ensure_ascii, indent_step, current_indent); + o->write_character(','); + } + + // last element + assert(i != val.m_value.object->cend()); + assert(std::next(i) == val.m_value.object->cend()); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\":", 2); + dump(i->second, false, ensure_ascii, indent_step, current_indent); + + o->write_character('}'); + } + + return; + } + + case value_t::array: + { + if (val.m_value.array->empty()) + { + o->write_characters("[]", 2); + return; + } + + if (pretty_print) + { + o->write_characters("[\n", 2); + + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } + + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + dump(*i, true, ensure_ascii, indent_step, new_indent); + o->write_characters(",\n", 2); + } + + // last element + assert(not val.m_value.array->empty()); + o->write_characters(indent_string.c_str(), new_indent); + dump(val.m_value.array->back(), true, ensure_ascii, indent_step, new_indent); + + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character(']'); + } + else + { + o->write_character('['); + + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + dump(*i, false, ensure_ascii, indent_step, current_indent); + o->write_character(','); + } + + // last element + assert(not val.m_value.array->empty()); + dump(val.m_value.array->back(), false, ensure_ascii, indent_step, current_indent); + + o->write_character(']'); + } + + return; + } + + case value_t::string: + { + o->write_character('\"'); + dump_escaped(*val.m_value.string, ensure_ascii); + o->write_character('\"'); + return; + } + + case value_t::boolean: + { + if (val.m_value.boolean) + { + o->write_characters("true", 4); + } + else + { + o->write_characters("false", 5); + } + return; + } + + case value_t::number_integer: + { + dump_integer(val.m_value.number_integer); + return; + } + + case value_t::number_unsigned: + { + dump_integer(val.m_value.number_unsigned); + return; + } + + case value_t::number_float: + { + dump_float(val.m_value.number_float); + return; + } + + case value_t::discarded: + { + o->write_characters("", 11); + return; + } + + case value_t::null: + { + o->write_characters("null", 4); + return; + } + } + } + + private: + /*! + @brief returns the number of expected bytes following in UTF-8 string + + @param[in] u the first byte of a UTF-8 string + @return the number of expected bytes following + */ + static constexpr std::size_t bytes_following(const uint8_t u) + { + return ((u <= 127) ? 0 + : ((192 <= u and u <= 223) ? 1 + : ((224 <= u and u <= 239) ? 2 + : ((240 <= u and u <= 247) ? 3 : std::string::npos)))); + } + + /*! + @brief calculates the extra space to escape a JSON string + + @param[in] s the string to escape + @param[in] ensure_ascii whether to escape non-ASCII characters with + \uXXXX sequences + @return the number of characters required to escape string @a s + + @complexity Linear in the length of string @a s. + */ + static std::size_t extra_space(const string_t& s, + const bool ensure_ascii) noexcept + { + std::size_t res = 0; + + for (std::size_t i = 0; i < s.size(); ++i) + { + switch (s[i]) + { + // control characters that can be escaped with a backslash + case '"': + case '\\': + case '\b': + case '\f': + case '\n': + case '\r': + case '\t': + { + // from c (1 byte) to \x (2 bytes) + res += 1; + break; + } + + // control characters that need \uxxxx escaping + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x0B: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1A: + case 0x1B: + case 0x1C: + case 0x1D: + case 0x1E: + case 0x1F: + { + // from c (1 byte) to \uxxxx (6 bytes) + res += 5; + break; + } + + default: + { + if (ensure_ascii and (s[i] & 0x80 or s[i] == 0x7F)) + { + const auto bytes = bytes_following(static_cast(s[i])); + // invalid characters will be detected by throw_if_invalid_utf8 + assert (bytes != std::string::npos); + + if (bytes == 3) + { + // codepoints that need 4 bytes (i.e., 3 additional + // bytes) in UTF-8 need a surrogate pair when \u + // escaping is used: from 4 bytes to \uxxxx\uxxxx + // (12 bytes) + res += (12 - bytes - 1); + } + else + { + // from x bytes to \uxxxx (6 bytes) + res += (6 - bytes - 1); + } + + // skip the additional bytes + i += bytes; + } + break; + } + } + } + + return res; + } + + static void escape_codepoint(int codepoint, string_t& result, std::size_t& pos) + { + // expecting a proper codepoint + assert(0x00 <= codepoint and codepoint <= 0x10FFFF); + + // the last written character was the backslash before the 'u' + assert(result[pos] == '\\'); + + // write the 'u' + result[++pos] = 'u'; + + // convert a number 0..15 to its hex representation (0..f) + static const std::array hexify = + { + { + '0', '1', '2', '3', '4', '5', '6', '7', + '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' + } + }; + + if (codepoint < 0x10000) + { + // codepoints U+0000..U+FFFF can be represented as \uxxxx. + result[++pos] = hexify[(codepoint >> 12) & 0x0F]; + result[++pos] = hexify[(codepoint >> 8) & 0x0F]; + result[++pos] = hexify[(codepoint >> 4) & 0x0F]; + result[++pos] = hexify[codepoint & 0x0F]; + } + else + { + // codepoints U+10000..U+10FFFF need a surrogate pair to be + // represented as \uxxxx\uxxxx. + // http://www.unicode.org/faq/utf_bom.html#utf16-4 + codepoint -= 0x10000; + const int high_surrogate = 0xD800 | ((codepoint >> 10) & 0x3FF); + const int low_surrogate = 0xDC00 | (codepoint & 0x3FF); + result[++pos] = hexify[(high_surrogate >> 12) & 0x0F]; + result[++pos] = hexify[(high_surrogate >> 8) & 0x0F]; + result[++pos] = hexify[(high_surrogate >> 4) & 0x0F]; + result[++pos] = hexify[high_surrogate & 0x0F]; + ++pos; // backslash is already in output + result[++pos] = 'u'; + result[++pos] = hexify[(low_surrogate >> 12) & 0x0F]; + result[++pos] = hexify[(low_surrogate >> 8) & 0x0F]; + result[++pos] = hexify[(low_surrogate >> 4) & 0x0F]; + result[++pos] = hexify[low_surrogate & 0x0F]; + } + + ++pos; + } + + /*! + @brief dump escaped string + + Escape a string by replacing certain special characters by a sequence of an + escape character (backslash) and another character and other control + characters by a sequence of "\u" followed by a four-digit hex + representation. The escaped string is written to output stream @a o. + + @param[in] s the string to escape + @param[in] ensure_ascii whether to escape non-ASCII characters with + \uXXXX sequences + + @complexity Linear in the length of string @a s. + */ + void dump_escaped(const string_t& s, const bool ensure_ascii) const + { + throw_if_invalid_utf8(s); + + const auto space = extra_space(s, ensure_ascii); + if (space == 0) + { + o->write_characters(s.c_str(), s.size()); + return; + } + + // create a result string of necessary size + string_t result(s.size() + space, '\\'); + std::size_t pos = 0; + + for (std::size_t i = 0; i < s.size(); ++i) + { + switch (s[i]) + { + case '"': // quotation mark (0x22) + { + result[pos + 1] = '"'; + pos += 2; + break; + } + + case '\\': // reverse solidus (0x5C) + { + // nothing to change + pos += 2; + break; + } + + case '\b': // backspace (0x08) + { + result[pos + 1] = 'b'; + pos += 2; + break; + } + + case '\f': // formfeed (0x0C) + { + result[pos + 1] = 'f'; + pos += 2; + break; + } + + case '\n': // newline (0x0A) + { + result[pos + 1] = 'n'; + pos += 2; + break; + } + + case '\r': // carriage return (0x0D) + { + result[pos + 1] = 'r'; + pos += 2; + break; + } + + case '\t': // horizontal tab (0x09) + { + result[pos + 1] = 't'; + pos += 2; + break; + } + + default: + { + // escape control characters (0x00..0x1F) or, if + // ensure_ascii parameter is used, non-ASCII characters + if ((0x00 <= s[i] and s[i] <= 0x1F) or + (ensure_ascii and (s[i] & 0x80 or s[i] == 0x7F))) + { + const auto bytes = bytes_following(static_cast(s[i])); + // invalid characters will be detected by throw_if_invalid_utf8 + assert (bytes != std::string::npos); + + // check that the additional bytes are present + assert(i + bytes < s.size()); + + // to use \uxxxx escaping, we first need to calculate + // the codepoint from the UTF-8 bytes + int codepoint = 0; + + // bytes is unsigned type: + assert(bytes <= 3); + switch (bytes) + { + case 0: + { + codepoint = s[i] & 0xFF; + break; + } + + case 1: + { + codepoint = ((s[i] & 0x3F) << 6) + + (s[i + 1] & 0x7F); + break; + } + + case 2: + { + codepoint = ((s[i] & 0x1F) << 12) + + ((s[i + 1] & 0x7F) << 6) + + (s[i + 2] & 0x7F); + break; + } + + case 3: + { + codepoint = ((s[i] & 0xF) << 18) + + ((s[i + 1] & 0x7F) << 12) + + ((s[i + 2] & 0x7F) << 6) + + (s[i + 3] & 0x7F); + break; + } + + default: + break; // LCOV_EXCL_LINE + } + + escape_codepoint(codepoint, result, pos); + i += bytes; + } + else + { + // all other characters are added as-is + result[pos++] = s[i]; + } + break; + } + } + } + + assert(pos == result.size()); + o->write_characters(result.c_str(), result.size()); + } + + /*! + @brief dump an integer + + Dump a given integer to output stream @a o. Works internally with + @a number_buffer. + + @param[in] x integer number (signed or unsigned) to dump + @tparam NumberType either @a number_integer_t or @a number_unsigned_t + */ + template::value or + std::is_same::value, + int> = 0> + void dump_integer(NumberType x) + { + // special case for "0" + if (x == 0) + { + o->write_character('0'); + return; + } + + const bool is_negative = (x <= 0) and (x != 0); // see issue #755 + std::size_t i = 0; + + while (x != 0) + { + // spare 1 byte for '\0' + assert(i < number_buffer.size() - 1); + + const auto digit = std::labs(static_cast(x % 10)); + number_buffer[i++] = static_cast('0' + digit); + x /= 10; + } + + if (is_negative) + { + // make sure there is capacity for the '-' + assert(i < number_buffer.size() - 2); + number_buffer[i++] = '-'; + } + + std::reverse(number_buffer.begin(), number_buffer.begin() + i); + o->write_characters(number_buffer.data(), i); + } + + /*! + @brief dump a floating-point number + + Dump a given floating-point number to output stream @a o. Works internally + with @a number_buffer. + + @param[in] x floating-point number to dump + */ + void dump_float(number_float_t x) + { + // NaN / inf + if (not std::isfinite(x) or std::isnan(x)) + { + o->write_characters("null", 4); + return; + } + + // get number of digits for a text -> float -> text round-trip + static constexpr auto d = std::numeric_limits::digits10; + + // the actual conversion + std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), "%.*g", d, x); + + // negative value indicates an error + assert(len > 0); + // check if buffer was large enough + assert(static_cast(len) < number_buffer.size()); + + // erase thousands separator + if (thousands_sep != '\0') + { + const auto end = std::remove(number_buffer.begin(), + number_buffer.begin() + len, thousands_sep); + std::fill(end, number_buffer.end(), '\0'); + assert((end - number_buffer.begin()) <= len); + len = (end - number_buffer.begin()); + } + + // convert decimal point to '.' + if (decimal_point != '\0' and decimal_point != '.') + { + const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), decimal_point); + if (dec_pos != number_buffer.end()) + { + *dec_pos = '.'; + } + } + + o->write_characters(number_buffer.data(), static_cast(len)); + + // determine if need to append ".0" + const bool value_is_int_like = + std::none_of(number_buffer.begin(), number_buffer.begin() + len + 1, + [](char c) + { + return (c == '.' or c == 'e'); + }); + + if (value_is_int_like) + { + o->write_characters(".0", 2); + } + } + + /*! + @brief check whether a string is UTF-8 encoded + + The function checks each byte of a string whether it is UTF-8 encoded. The + result of the check is stored in the @a state parameter. The function must + be called initially with state 0 (accept). State 1 means the string must + be rejected, because the current byte is not allowed. If the string is + completely processed, but the state is non-zero, the string ended + prematurely; that is, the last byte indicated more bytes should have + followed. + + @param[in,out] state the state of the decoding + @param[in] byte next byte to decode + + @note The function has been edited: a std::array is used and the code + point is not calculated. + + @copyright Copyright (c) 2008-2009 Bjoern Hoehrmann + @sa http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ + */ + static void decode(uint8_t& state, const uint8_t byte) + { + static const std::array utf8d = + { + { + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 00..1F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 20..3F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 40..5F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 60..7F + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, // 80..9F + 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // A0..BF + 8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, // C0..DF + 0xA, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x4, 0x3, 0x3, // E0..EF + 0xB, 0x6, 0x6, 0x6, 0x5, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, // F0..FF + 0x0, 0x1, 0x2, 0x3, 0x5, 0x8, 0x7, 0x1, 0x1, 0x1, 0x4, 0x6, 0x1, 0x1, 0x1, 0x1, // s0..s0 + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, // s1..s2 + 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, // s3..s4 + 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, // s5..s6 + 1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 // s7..s8 + } + }; + + const uint8_t type = utf8d[byte]; + state = utf8d[256u + state * 16u + type]; + } + + /*! + @brief throw an exception if a string is not UTF-8 encoded + + @param[in] str UTF-8 string to check + @throw type_error.316 if passed string is not UTF-8 encoded + + @since version 3.0.0 + */ + static void throw_if_invalid_utf8(const std::string& str) + { + // start with state 0 (= accept) + uint8_t state = 0; + + for (size_t i = 0; i < str.size(); ++i) + { + const auto byte = static_cast(str[i]); + decode(state, byte); + if (state == 1) + { + // state 1 means reject + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast(byte); + JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + ss.str())); + } + } + + if (state != 0) + { + // we finish reading, but do not accept: string was incomplete + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast(static_cast(str.back())); + JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + ss.str())); + } + } + + private: + /// the output of the serializer + output_adapter_t o = nullptr; + + /// a (hopefully) large enough character buffer + std::array number_buffer{{}}; + + /// the locale + const std::lconv* loc = nullptr; + /// the locale's thousand separator character + const char thousands_sep = '\0'; + /// the locale's decimal point character + const char decimal_point = '\0'; + + /// the indentation character + const char indent_char; + + /// the indentation string + string_t indent_string; +}; +} +} + +#endif diff --git a/src/json.hpp b/src/json.hpp index ff1af030..d52d6e83 100644 --- a/src/json.hpp +++ b/src/json.hpp @@ -68,6 +68,7 @@ SOFTWARE. #include "detail/parsing/output_adapters.hpp" #include "detail/parsing/binary_reader.hpp" #include "detail/parsing/binary_writer.hpp" +#include "detail/serializer.hpp" /*! @brief namespace for Niels Lohmann @@ -78,774 +79,6 @@ namespace nlohmann { namespace detail { -/////////////////// -// serialization // -/////////////////// - -template -class serializer -{ - using string_t = typename BasicJsonType::string_t; - using number_float_t = typename BasicJsonType::number_float_t; - using number_integer_t = typename BasicJsonType::number_integer_t; - using number_unsigned_t = typename BasicJsonType::number_unsigned_t; - public: - /*! - @param[in] s output stream to serialize to - @param[in] ichar indentation character to use - */ - serializer(output_adapter_t s, const char ichar) - : o(std::move(s)), loc(std::localeconv()), - thousands_sep(loc->thousands_sep == nullptr ? '\0' : * (loc->thousands_sep)), - decimal_point(loc->decimal_point == nullptr ? '\0' : * (loc->decimal_point)), - indent_char(ichar), indent_string(512, indent_char) {} - - // delete because of pointer members - serializer(const serializer&) = delete; - serializer& operator=(const serializer&) = delete; - - /*! - @brief internal implementation of the serialization function - - This function is called by the public member function dump and organizes - the serialization internally. The indentation level is propagated as - additional parameter. In case of arrays and objects, the function is - called recursively. - - - strings and object keys are escaped using `escape_string()` - - integer numbers are converted implicitly via `operator<<` - - floating-point numbers are converted to a string using `"%g"` format - - @param[in] val value to serialize - @param[in] pretty_print whether the output shall be pretty-printed - @param[in] indent_step the indent level - @param[in] current_indent the current indent level (only used internally) - */ - void dump(const BasicJsonType& val, const bool pretty_print, - const bool ensure_ascii, - const unsigned int indent_step, - const unsigned int current_indent = 0) - { - switch (val.m_type) - { - case value_t::object: - { - if (val.m_value.object->empty()) - { - o->write_characters("{}", 2); - return; - } - - if (pretty_print) - { - o->write_characters("{\n", 2); - - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (JSON_UNLIKELY(indent_string.size() < new_indent)) - { - indent_string.resize(indent_string.size() * 2, ' '); - } - - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first, ensure_ascii); - o->write_characters("\": ", 3); - dump(i->second, true, ensure_ascii, indent_step, new_indent); - o->write_characters(",\n", 2); - } - - // last element - assert(i != val.m_value.object->cend()); - assert(std::next(i) == val.m_value.object->cend()); - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first, ensure_ascii); - o->write_characters("\": ", 3); - dump(i->second, true, ensure_ascii, indent_step, new_indent); - - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character('}'); - } - else - { - o->write_character('{'); - - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_character('\"'); - dump_escaped(i->first, ensure_ascii); - o->write_characters("\":", 2); - dump(i->second, false, ensure_ascii, indent_step, current_indent); - o->write_character(','); - } - - // last element - assert(i != val.m_value.object->cend()); - assert(std::next(i) == val.m_value.object->cend()); - o->write_character('\"'); - dump_escaped(i->first, ensure_ascii); - o->write_characters("\":", 2); - dump(i->second, false, ensure_ascii, indent_step, current_indent); - - o->write_character('}'); - } - - return; - } - - case value_t::array: - { - if (val.m_value.array->empty()) - { - o->write_characters("[]", 2); - return; - } - - if (pretty_print) - { - o->write_characters("[\n", 2); - - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (JSON_UNLIKELY(indent_string.size() < new_indent)) - { - indent_string.resize(indent_string.size() * 2, ' '); - } - - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); - i != val.m_value.array->cend() - 1; ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - dump(*i, true, ensure_ascii, indent_step, new_indent); - o->write_characters(",\n", 2); - } - - // last element - assert(not val.m_value.array->empty()); - o->write_characters(indent_string.c_str(), new_indent); - dump(val.m_value.array->back(), true, ensure_ascii, indent_step, new_indent); - - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character(']'); - } - else - { - o->write_character('['); - - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); - i != val.m_value.array->cend() - 1; ++i) - { - dump(*i, false, ensure_ascii, indent_step, current_indent); - o->write_character(','); - } - - // last element - assert(not val.m_value.array->empty()); - dump(val.m_value.array->back(), false, ensure_ascii, indent_step, current_indent); - - o->write_character(']'); - } - - return; - } - - case value_t::string: - { - o->write_character('\"'); - dump_escaped(*val.m_value.string, ensure_ascii); - o->write_character('\"'); - return; - } - - case value_t::boolean: - { - if (val.m_value.boolean) - { - o->write_characters("true", 4); - } - else - { - o->write_characters("false", 5); - } - return; - } - - case value_t::number_integer: - { - dump_integer(val.m_value.number_integer); - return; - } - - case value_t::number_unsigned: - { - dump_integer(val.m_value.number_unsigned); - return; - } - - case value_t::number_float: - { - dump_float(val.m_value.number_float); - return; - } - - case value_t::discarded: - { - o->write_characters("", 11); - return; - } - - case value_t::null: - { - o->write_characters("null", 4); - return; - } - } - } - - private: - /*! - @brief returns the number of expected bytes following in UTF-8 string - - @param[in] u the first byte of a UTF-8 string - @return the number of expected bytes following - */ - static constexpr std::size_t bytes_following(const uint8_t u) - { - return ((u <= 127) ? 0 - : ((192 <= u and u <= 223) ? 1 - : ((224 <= u and u <= 239) ? 2 - : ((240 <= u and u <= 247) ? 3 : std::string::npos)))); - } - - /*! - @brief calculates the extra space to escape a JSON string - - @param[in] s the string to escape - @param[in] ensure_ascii whether to escape non-ASCII characters with - \uXXXX sequences - @return the number of characters required to escape string @a s - - @complexity Linear in the length of string @a s. - */ - static std::size_t extra_space(const string_t& s, - const bool ensure_ascii) noexcept - { - std::size_t res = 0; - - for (std::size_t i = 0; i < s.size(); ++i) - { - switch (s[i]) - { - // control characters that can be escaped with a backslash - case '"': - case '\\': - case '\b': - case '\f': - case '\n': - case '\r': - case '\t': - { - // from c (1 byte) to \x (2 bytes) - res += 1; - break; - } - - // control characters that need \uxxxx escaping - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0B: - case 0x0E: - case 0x0F: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1A: - case 0x1B: - case 0x1C: - case 0x1D: - case 0x1E: - case 0x1F: - { - // from c (1 byte) to \uxxxx (6 bytes) - res += 5; - break; - } - - default: - { - if (ensure_ascii and (s[i] & 0x80 or s[i] == 0x7F)) - { - const auto bytes = bytes_following(static_cast(s[i])); - // invalid characters will be detected by throw_if_invalid_utf8 - assert (bytes != std::string::npos); - - if (bytes == 3) - { - // codepoints that need 4 bytes (i.e., 3 additional - // bytes) in UTF-8 need a surrogate pair when \u - // escaping is used: from 4 bytes to \uxxxx\uxxxx - // (12 bytes) - res += (12 - bytes - 1); - } - else - { - // from x bytes to \uxxxx (6 bytes) - res += (6 - bytes - 1); - } - - // skip the additional bytes - i += bytes; - } - break; - } - } - } - - return res; - } - - static void escape_codepoint(int codepoint, string_t& result, std::size_t& pos) - { - // expecting a proper codepoint - assert(0x00 <= codepoint and codepoint <= 0x10FFFF); - - // the last written character was the backslash before the 'u' - assert(result[pos] == '\\'); - - // write the 'u' - result[++pos] = 'u'; - - // convert a number 0..15 to its hex representation (0..f) - static const std::array hexify = - { - { - '0', '1', '2', '3', '4', '5', '6', '7', - '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' - } - }; - - if (codepoint < 0x10000) - { - // codepoints U+0000..U+FFFF can be represented as \uxxxx. - result[++pos] = hexify[(codepoint >> 12) & 0x0F]; - result[++pos] = hexify[(codepoint >> 8) & 0x0F]; - result[++pos] = hexify[(codepoint >> 4) & 0x0F]; - result[++pos] = hexify[codepoint & 0x0F]; - } - else - { - // codepoints U+10000..U+10FFFF need a surrogate pair to be - // represented as \uxxxx\uxxxx. - // http://www.unicode.org/faq/utf_bom.html#utf16-4 - codepoint -= 0x10000; - const int high_surrogate = 0xD800 | ((codepoint >> 10) & 0x3FF); - const int low_surrogate = 0xDC00 | (codepoint & 0x3FF); - result[++pos] = hexify[(high_surrogate >> 12) & 0x0F]; - result[++pos] = hexify[(high_surrogate >> 8) & 0x0F]; - result[++pos] = hexify[(high_surrogate >> 4) & 0x0F]; - result[++pos] = hexify[high_surrogate & 0x0F]; - ++pos; // backslash is already in output - result[++pos] = 'u'; - result[++pos] = hexify[(low_surrogate >> 12) & 0x0F]; - result[++pos] = hexify[(low_surrogate >> 8) & 0x0F]; - result[++pos] = hexify[(low_surrogate >> 4) & 0x0F]; - result[++pos] = hexify[low_surrogate & 0x0F]; - } - - ++pos; - } - - /*! - @brief dump escaped string - - Escape a string by replacing certain special characters by a sequence of an - escape character (backslash) and another character and other control - characters by a sequence of "\u" followed by a four-digit hex - representation. The escaped string is written to output stream @a o. - - @param[in] s the string to escape - @param[in] ensure_ascii whether to escape non-ASCII characters with - \uXXXX sequences - - @complexity Linear in the length of string @a s. - */ - void dump_escaped(const string_t& s, const bool ensure_ascii) const - { - throw_if_invalid_utf8(s); - - const auto space = extra_space(s, ensure_ascii); - if (space == 0) - { - o->write_characters(s.c_str(), s.size()); - return; - } - - // create a result string of necessary size - string_t result(s.size() + space, '\\'); - std::size_t pos = 0; - - for (std::size_t i = 0; i < s.size(); ++i) - { - switch (s[i]) - { - case '"': // quotation mark (0x22) - { - result[pos + 1] = '"'; - pos += 2; - break; - } - - case '\\': // reverse solidus (0x5C) - { - // nothing to change - pos += 2; - break; - } - - case '\b': // backspace (0x08) - { - result[pos + 1] = 'b'; - pos += 2; - break; - } - - case '\f': // formfeed (0x0C) - { - result[pos + 1] = 'f'; - pos += 2; - break; - } - - case '\n': // newline (0x0A) - { - result[pos + 1] = 'n'; - pos += 2; - break; - } - - case '\r': // carriage return (0x0D) - { - result[pos + 1] = 'r'; - pos += 2; - break; - } - - case '\t': // horizontal tab (0x09) - { - result[pos + 1] = 't'; - pos += 2; - break; - } - - default: - { - // escape control characters (0x00..0x1F) or, if - // ensure_ascii parameter is used, non-ASCII characters - if ((0x00 <= s[i] and s[i] <= 0x1F) or - (ensure_ascii and (s[i] & 0x80 or s[i] == 0x7F))) - { - const auto bytes = bytes_following(static_cast(s[i])); - // invalid characters will be detected by throw_if_invalid_utf8 - assert (bytes != std::string::npos); - - // check that the additional bytes are present - assert(i + bytes < s.size()); - - // to use \uxxxx escaping, we first need to calculate - // the codepoint from the UTF-8 bytes - int codepoint = 0; - - // bytes is unsigned type: - assert(bytes <= 3); - switch (bytes) - { - case 0: - { - codepoint = s[i] & 0xFF; - break; - } - - case 1: - { - codepoint = ((s[i] & 0x3F) << 6) - + (s[i + 1] & 0x7F); - break; - } - - case 2: - { - codepoint = ((s[i] & 0x1F) << 12) - + ((s[i + 1] & 0x7F) << 6) - + (s[i + 2] & 0x7F); - break; - } - - case 3: - { - codepoint = ((s[i] & 0xF) << 18) - + ((s[i + 1] & 0x7F) << 12) - + ((s[i + 2] & 0x7F) << 6) - + (s[i + 3] & 0x7F); - break; - } - - default: - break; // LCOV_EXCL_LINE - } - - escape_codepoint(codepoint, result, pos); - i += bytes; - } - else - { - // all other characters are added as-is - result[pos++] = s[i]; - } - break; - } - } - } - - assert(pos == result.size()); - o->write_characters(result.c_str(), result.size()); - } - - /*! - @brief dump an integer - - Dump a given integer to output stream @a o. Works internally with - @a number_buffer. - - @param[in] x integer number (signed or unsigned) to dump - @tparam NumberType either @a number_integer_t or @a number_unsigned_t - */ - template::value or - std::is_same::value, - int> = 0> - void dump_integer(NumberType x) - { - // special case for "0" - if (x == 0) - { - o->write_character('0'); - return; - } - - const bool is_negative = (x <= 0) and (x != 0); // see issue #755 - std::size_t i = 0; - - while (x != 0) - { - // spare 1 byte for '\0' - assert(i < number_buffer.size() - 1); - - const auto digit = std::labs(static_cast(x % 10)); - number_buffer[i++] = static_cast('0' + digit); - x /= 10; - } - - if (is_negative) - { - // make sure there is capacity for the '-' - assert(i < number_buffer.size() - 2); - number_buffer[i++] = '-'; - } - - std::reverse(number_buffer.begin(), number_buffer.begin() + i); - o->write_characters(number_buffer.data(), i); - } - - /*! - @brief dump a floating-point number - - Dump a given floating-point number to output stream @a o. Works internally - with @a number_buffer. - - @param[in] x floating-point number to dump - */ - void dump_float(number_float_t x) - { - // NaN / inf - if (not std::isfinite(x) or std::isnan(x)) - { - o->write_characters("null", 4); - return; - } - - // get number of digits for a text -> float -> text round-trip - static constexpr auto d = std::numeric_limits::digits10; - - // the actual conversion - std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), "%.*g", d, x); - - // negative value indicates an error - assert(len > 0); - // check if buffer was large enough - assert(static_cast(len) < number_buffer.size()); - - // erase thousands separator - if (thousands_sep != '\0') - { - const auto end = std::remove(number_buffer.begin(), - number_buffer.begin() + len, thousands_sep); - std::fill(end, number_buffer.end(), '\0'); - assert((end - number_buffer.begin()) <= len); - len = (end - number_buffer.begin()); - } - - // convert decimal point to '.' - if (decimal_point != '\0' and decimal_point != '.') - { - const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), decimal_point); - if (dec_pos != number_buffer.end()) - { - *dec_pos = '.'; - } - } - - o->write_characters(number_buffer.data(), static_cast(len)); - - // determine if need to append ".0" - const bool value_is_int_like = - std::none_of(number_buffer.begin(), number_buffer.begin() + len + 1, - [](char c) - { - return (c == '.' or c == 'e'); - }); - - if (value_is_int_like) - { - o->write_characters(".0", 2); - } - } - - /*! - @brief check whether a string is UTF-8 encoded - - The function checks each byte of a string whether it is UTF-8 encoded. The - result of the check is stored in the @a state parameter. The function must - be called initially with state 0 (accept). State 1 means the string must - be rejected, because the current byte is not allowed. If the string is - completely processed, but the state is non-zero, the string ended - prematurely; that is, the last byte indicated more bytes should have - followed. - - @param[in,out] state the state of the decoding - @param[in] byte next byte to decode - - @note The function has been edited: a std::array is used and the code - point is not calculated. - - @copyright Copyright (c) 2008-2009 Bjoern Hoehrmann - @sa http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ - */ - static void decode(uint8_t& state, const uint8_t byte) - { - static const std::array utf8d = - { - { - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 00..1F - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 20..3F - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 40..5F - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 60..7F - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, // 80..9F - 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // A0..BF - 8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, // C0..DF - 0xA, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x4, 0x3, 0x3, // E0..EF - 0xB, 0x6, 0x6, 0x6, 0x5, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, // F0..FF - 0x0, 0x1, 0x2, 0x3, 0x5, 0x8, 0x7, 0x1, 0x1, 0x1, 0x4, 0x6, 0x1, 0x1, 0x1, 0x1, // s0..s0 - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, // s1..s2 - 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, // s3..s4 - 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, // s5..s6 - 1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 // s7..s8 - } - }; - - const uint8_t type = utf8d[byte]; - state = utf8d[256u + state * 16u + type]; - } - - /*! - @brief throw an exception if a string is not UTF-8 encoded - - @param[in] str UTF-8 string to check - @throw type_error.316 if passed string is not UTF-8 encoded - - @since version 3.0.0 - */ - static void throw_if_invalid_utf8(const std::string& str) - { - // start with state 0 (= accept) - uint8_t state = 0; - - for (size_t i = 0; i < str.size(); ++i) - { - const auto byte = static_cast(str[i]); - decode(state, byte); - if (state == 1) - { - // state 1 means reject - std::stringstream ss; - ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast(byte); - JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + ss.str())); - } - } - - if (state != 0) - { - // we finish reading, but do not accept: string was incomplete - std::stringstream ss; - ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast(static_cast(str.back())); - JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + ss.str())); - } - } - - private: - /// the output of the serializer - output_adapter_t o = nullptr; - - /// a (hopefully) large enough character buffer - std::array number_buffer{{}}; - - /// the locale - const std::lconv* loc = nullptr; - /// the locale's thousand separator character - const char thousands_sep = '\0'; - /// the locale's decimal point character - const char decimal_point = '\0'; - - /// the indentation character - const char indent_char; - - /// the indentation string - string_t indent_string; -}; - template class json_ref {