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♻️ re-used existing UTF-8 decoder to simplfy string serialization

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Niels Lohmann 2018-01-16 20:42:00 +01:00
parent afe4571309
commit 7456f1d87b
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GPG key ID: 7F3CEA63AE251B69
2 changed files with 307 additions and 691 deletions
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465
develop/detail/serializer.hpp
View file

@ -34,6 +34,9 @@ class serializer
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;
static constexpr uint8_t UTF8_ACCEPT = 0;
static constexpr uint8_t UTF8_REJECT = 1;
public:
/*!
@param[in] s output stream to serialize to
@ -43,7 +46,8 @@ class serializer
: 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) {}
indent_char(ichar), indent_string(512, indent_char)
{}
// delete because of pointer members
serializer(const serializer&) = delete;
@ -259,171 +263,6 @@ class serializer
}
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<uint8_t>(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<char, 16> 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
@ -438,145 +277,145 @@ class serializer
@complexity Linear in the length of string @a s.
*/
void dump_escaped(const string_t& s, const bool ensure_ascii) const
void dump_escaped(const string_t& s, const bool ensure_ascii)
{
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;
uint32_t codepoint;
uint8_t state = UTF8_ACCEPT;
std::size_t bytes = 0; // number of bytes written to string_buffer
for (std::size_t i = 0; i < s.size(); ++i)
{
switch (s[i])
const auto byte = static_cast<uint8_t>(s[i]);
switch (decode(state, codepoint, byte))
{
case '"': // quotation mark (0x22)
case UTF8_ACCEPT: // decode found a new code point
{
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)))
switch (codepoint)
{
const auto bytes = bytes_following(static_cast<uint8_t>(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 0x08: // backspace
{
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
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 'b';
break;
}
escape_codepoint(codepoint, result, pos);
i += bytes;
case 0x09: // horizontal tab
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 't';
break;
}
case 0x0A: // newline
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 'n';
break;
}
case 0x0C: // formfeed
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 'f';
break;
}
case 0x0D: // carriage return
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 'r';
break;
}
case 0x22: // quotation mark
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = '\"';
break;
}
case 0x5C: // reverse solidus
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = '\\';
break;
}
default:
{
// escape control characters (0x00..0x1F) or, if
// ensure_ascii parameter is used, non-ASCII characters
if ((codepoint <= 0x1F) or (ensure_ascii and (codepoint >= 0x7F)))
{
if (codepoint <= 0xFFFF)
{
std::snprintf(string_buffer.data() + bytes, 7, "\\u%04x", codepoint);
bytes += 6;
}
else
{
std::snprintf(string_buffer.data() + bytes, 13, "\\u%04x\\u%04x",
(0xD7C0 + (codepoint >> 10)),
(0xDC00 + (codepoint & 0x3FF)));
bytes += 12;
}
}
else
{
// copy byte to buffer (all previous bytes
// been copied have in default case above)
string_buffer[bytes++] = s[i];
}
break;
}
}
else
// write buffer and reset index; there must be 13 bytes
// left, as this is the maximal number of bytes to be
// written ("\uxxxx\uxxxx\0") for one code point
if (string_buffer.size() - bytes < 13)
{
// all other characters are added as-is
result[pos++] = s[i];
o->write_characters(string_buffer.data(), bytes);
bytes = 0;
}
break;
}
case UTF8_REJECT: // decode found invalid UTF-8 byte
{
std::stringstream ss;
ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast<int>(byte);
JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + ss.str()));
}
default: // decode found yet incomplete multi-byte code point
{
if (not ensure_ascii)
{
// code point will not be escaped - copy byte to buffer
string_buffer[bytes++] = s[i];
}
break;
}
}
}
assert(pos == result.size());
o->write_characters(result.c_str(), result.size());
if (JSON_LIKELY(state == UTF8_ACCEPT))
{
// write buffer
if (bytes > 0)
{
o->write_characters(string_buffer.data(), bytes);
}
}
else
{
// 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<int>(static_cast<uint8_t>(s.back()));
JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + ss.str()));
}
}
/*!
@ -701,15 +540,16 @@ class serializer
followed.
@param[in,out] state the state of the decoding
@param[in,out] codep codepoint (valid only if resulting state is UTF8_ACCEPT)
@param[in] byte next byte to decode
@return new state
@note The function has been edited: a std::array is used and the code
point is not calculated.
@note The function has been edited: a std::array is used.
@copyright Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
@sa http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
*/
static void decode(uint8_t& state, const uint8_t byte)
static uint8_t decode(uint8_t& state, uint32_t& codep, const uint8_t byte) noexcept
{
static const std::array<uint8_t, 400> utf8d =
{
@ -732,42 +572,13 @@ class serializer
};
const uint8_t type = utf8d[byte];
codep = (state != UTF8_ACCEPT)
? (byte & 0x3fu) | (codep << 6)
: (0xff >> type) & (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<uint8_t>(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<int>(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<int>(static_cast<uint8_t>(str.back()));
JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + ss.str()));
}
return state;
}
private:
@ -784,9 +595,11 @@ class serializer
/// the locale's decimal point character
const char decimal_point = '\0';
/// string buffer
std::array<char, 512> string_buffer{{}};
/// the indentation character
const char indent_char;
/// the indentation string
string_t indent_string;
};

533
src/json.hpp
View file

@ -109,8 +109,6 @@ using json = basic_json<>;
// #include "detail/macro_scope.hpp"
#include <ciso646> // not
// This file contains all internal macro definitions
// You MUST include macro_unscope.hpp at the end of json.hpp to undef all of them
@ -147,7 +145,7 @@ using json = basic_json<>;
#endif
// allow to disable exceptions
#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && not defined(JSON_NOEXCEPTION)
#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && !defined(JSON_NOEXCEPTION)
#define JSON_THROW(exception) throw exception
#define JSON_TRY try
#define JSON_CATCH(exception) catch(exception)
@ -450,8 +448,7 @@ constexpr T static_const<T>::value;
}
// #include "detail/exceptions.hpp"
#ifndef NLOHMANN_JSON_DETAIL_EXCEPTIONS_HPP
#define NLOHMANN_JSON_DETAIL_EXCEPTIONS_HPP
#include <exception> // exception
#include <stdexcept> // runtime_error
@ -780,8 +777,6 @@ class other_error : public exception
}
}
#endif
// #include "detail/value_t.hpp"
@ -3667,10 +3662,8 @@ class parser
// #include "detail/iterators/primitive_iterator.hpp"
#include <ciso646> // not
#include <cstddef> // ptrdiff_t
#include <limits> // numeric_limits
#include <ostream> // ostream
namespace nlohmann
{
@ -3687,9 +3680,15 @@ end_value (`1`) models past the end.
*/
class primitive_iterator_t
{
public:
private:
using difference_type = std::ptrdiff_t;
static constexpr difference_type begin_value = 0;
static constexpr difference_type end_value = begin_value + 1;
/// iterator as signed integer type
difference_type m_it = (std::numeric_limits<std::ptrdiff_t>::min)();
public:
constexpr difference_type get_value() const noexcept
{
return m_it;
@ -3729,10 +3728,10 @@ class primitive_iterator_t
return lhs.m_it < rhs.m_it;
}
primitive_iterator_t operator+(difference_type i)
primitive_iterator_t operator+(difference_type n) noexcept
{
auto result = *this;
result += i;
result += n;
return result;
}
@ -3741,55 +3740,43 @@ class primitive_iterator_t
return lhs.m_it - rhs.m_it;
}
friend std::ostream& operator<<(std::ostream& os, primitive_iterator_t it)
{
return os << it.m_it;
}
primitive_iterator_t& operator++()
primitive_iterator_t& operator++() noexcept
{
++m_it;
return *this;
}
primitive_iterator_t const operator++(int)
primitive_iterator_t const operator++(int) noexcept
{
auto result = *this;
m_it++;
return result;
}
primitive_iterator_t& operator--()
primitive_iterator_t& operator--() noexcept
{
--m_it;
return *this;
}
primitive_iterator_t const operator--(int)
primitive_iterator_t const operator--(int) noexcept
{
auto result = *this;
m_it--;
return result;
}
primitive_iterator_t& operator+=(difference_type n)
primitive_iterator_t& operator+=(difference_type n) noexcept
{
m_it += n;
return *this;
}
primitive_iterator_t& operator-=(difference_type n)
primitive_iterator_t& operator-=(difference_type n) noexcept
{
m_it -= n;
return *this;
}
private:
static constexpr difference_type begin_value = 0;
static constexpr difference_type end_value = begin_value + 1;
/// iterator as signed integer type
difference_type m_it = (std::numeric_limits<std::ptrdiff_t>::min)();
};
}
}
@ -4527,7 +4514,7 @@ template<typename IteratorType> class iteration_proxy
public:
/// construct iteration proxy from a container
explicit iteration_proxy(typename IteratorType::reference cont)
explicit iteration_proxy(typename IteratorType::reference cont) noexcept
: container(cont) {}
/// return iterator begin (needed for range-based for)
@ -6477,6 +6464,9 @@ class serializer
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;
static constexpr uint8_t UTF8_ACCEPT = 0;
static constexpr uint8_t UTF8_REJECT = 1;
public:
/*!
@param[in] s output stream to serialize to
@ -6486,7 +6476,8 @@ class serializer
: 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) {}
indent_char(ichar), indent_string(512, indent_char)
{}
// delete because of pointer members
serializer(const serializer&) = delete;
@ -6702,171 +6693,6 @@ class serializer
}
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<uint8_t>(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<char, 16> 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
@ -6881,145 +6707,145 @@ class serializer
@complexity Linear in the length of string @a s.
*/
void dump_escaped(const string_t& s, const bool ensure_ascii) const
void dump_escaped(const string_t& s, const bool ensure_ascii)
{
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;
uint32_t codepoint;
uint8_t state = UTF8_ACCEPT;
std::size_t bytes = 0; // number of bytes written to string_buffer
for (std::size_t i = 0; i < s.size(); ++i)
{
switch (s[i])
const auto byte = static_cast<uint8_t>(s[i]);
switch (decode(state, codepoint, byte))
{
case '"': // quotation mark (0x22)
case UTF8_ACCEPT: // decode found a new code point
{
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)))
switch (codepoint)
{
const auto bytes = bytes_following(static_cast<uint8_t>(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 0x08: // backspace
{
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
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 'b';
break;
}
escape_codepoint(codepoint, result, pos);
i += bytes;
case 0x09: // horizontal tab
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 't';
break;
}
case 0x0A: // newline
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 'n';
break;
}
case 0x0C: // formfeed
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 'f';
break;
}
case 0x0D: // carriage return
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = 'r';
break;
}
case 0x22: // quotation mark
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = '\"';
break;
}
case 0x5C: // reverse solidus
{
string_buffer[bytes++] = '\\';
string_buffer[bytes++] = '\\';
break;
}
default:
{
// escape control characters (0x00..0x1F) or, if
// ensure_ascii parameter is used, non-ASCII characters
if ((codepoint <= 0x1F) or (ensure_ascii and (codepoint >= 0x7F)))
{
if (codepoint <= 0xFFFF)
{
std::snprintf(string_buffer.data() + bytes, 7, "\\u%04x", codepoint);
bytes += 6;
}
else
{
std::snprintf(string_buffer.data() + bytes, 13, "\\u%04x\\u%04x",
(0xD7C0 + (codepoint >> 10)),
(0xDC00 + (codepoint & 0x3FF)));
bytes += 12;
}
}
else
{
// copy byte to buffer (all previous bytes
// been copied have in default case above)
string_buffer[bytes++] = s[i];
}
break;
}
}
else
// write buffer and reset index; there must be 13 bytes
// left, as this is the maximal number of bytes to be
// written ("\uxxxx\uxxxx\0") for one code point
if (string_buffer.size() - bytes < 13)
{
// all other characters are added as-is
result[pos++] = s[i];
o->write_characters(string_buffer.data(), bytes);
bytes = 0;
}
break;
}
case UTF8_REJECT: // decode found invalid UTF-8 byte
{
std::stringstream ss;
ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast<int>(byte);
JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + ss.str()));
}
default: // decode found yet incomplete multi-byte code point
{
if (not ensure_ascii)
{
// code point will not be escaped - copy byte to buffer
string_buffer[bytes++] = s[i];
}
break;
}
}
}
assert(pos == result.size());
o->write_characters(result.c_str(), result.size());
if (JSON_LIKELY(state == UTF8_ACCEPT))
{
// write buffer
if (bytes > 0)
{
o->write_characters(string_buffer.data(), bytes);
}
}
else
{
// 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<int>(static_cast<uint8_t>(s.back()));
JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + ss.str()));
}
}
/*!
@ -7144,15 +6970,16 @@ class serializer
followed.
@param[in,out] state the state of the decoding
@param[in,out] codep codepoint (valid only if resulting state is UTF8_ACCEPT)
@param[in] byte next byte to decode
@return new state
@note The function has been edited: a std::array is used and the code
point is not calculated.
@note The function has been edited: a std::array is used.
@copyright Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
@sa http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
*/
static void decode(uint8_t& state, const uint8_t byte)
static uint8_t decode(uint8_t& state, uint32_t& codep, const uint8_t byte) noexcept
{
static const std::array<uint8_t, 400> utf8d =
{
@ -7175,42 +7002,13 @@ class serializer
};
const uint8_t type = utf8d[byte];
codep = (state != UTF8_ACCEPT)
? (byte & 0x3fu) | (codep << 6)
: (0xff >> type) & (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<uint8_t>(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<int>(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<int>(static_cast<uint8_t>(str.back()));
JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + ss.str()));
}
return state;
}
private:
@ -7227,9 +7025,11 @@ class serializer
/// the locale's decimal point character
const char decimal_point = '\0';
/// string buffer
std::array<char, 512> string_buffer{{}};
/// the indentation character
const char indent_char;
/// the indentation string
string_t indent_string;
};
@ -8589,7 +8389,7 @@ class basic_json
array = create<array_t>(std::move(value));
}
void destroy(value_t t)
void destroy(value_t t) noexcept
{
switch (t)
{
@ -8634,7 +8434,7 @@ class basic_json
value is changed, because the invariant expresses a relationship between
@a m_type and @a m_value.
*/
void assert_invariant() const
void assert_invariant() const noexcept
{
assert(m_type != value_t::object or m_value.object != nullptr);
assert(m_type != value_t::array or m_value.array != nullptr);
@ -9428,7 +9228,7 @@ class basic_json
@since version 1.0.0
*/
~basic_json()
~basic_json() noexcept
{
assert_invariant();
m_value.destroy(m_type);
@ -11769,7 +11569,7 @@ class basic_json
@note The name of this function is not yet final and may change in the
future.
*/
static iteration_proxy<iterator> iterator_wrapper(reference ref)
static iteration_proxy<iterator> iterator_wrapper(reference ref) noexcept
{
return iteration_proxy<iterator>(ref);
}
@ -11777,7 +11577,7 @@ class basic_json
/*!
@copydoc iterator_wrapper(reference)
*/
static iteration_proxy<const_iterator> iterator_wrapper(const_reference ref)
static iteration_proxy<const_iterator> iterator_wrapper(const_reference ref) noexcept
{
return iteration_proxy<const_iterator>(ref);
}
@ -11819,7 +11619,8 @@ class basic_json
@endcode
@note When iterating over an array, `key()` will return the index of the
element as string (see example).
element as string (see example). For primitive types (e.g., numbers),
`key()` returns an empty string.
@return iteration proxy object wrapping @a ref with an interface to use in
range-based for loops
@ -11830,8 +11631,10 @@ class basic_json
changes in the JSON value.
@complexity Constant.
@since version 3.x.x.
*/
iteration_proxy<iterator> items()
iteration_proxy<iterator> items() noexcept
{
return iteration_proxy<iterator>(*this);
}
@ -11839,7 +11642,7 @@ class basic_json
/*!
@copydoc items()
*/
iteration_proxy<const_iterator> items() const
iteration_proxy<const_iterator> items() const noexcept
{
return iteration_proxy<const_iterator>(*this);
}