json/include/nlohmann/detail/output/fancy_serializer.hpp
2018-06-02 00:23:00 -05:00

290 lines
10 KiB
C++

#pragma once
#include <algorithm> // reverse, remove, fill, find, none_of
#include <array> // array
#include <cassert> // assert
#include <ciso646> // and, or
#include <clocale> // localeconv, lconv
#include <cmath> // labs, isfinite, isnan, signbit
#include <cstddef> // size_t, ptrdiff_t
#include <cstdint> // uint8_t
#include <cstdio> // snprintf
#include <limits> // numeric_limits
#include <string> // string
#include <type_traits> // is_same
#include <nlohmann/detail/exceptions.hpp>
#include <nlohmann/detail/conversions/to_chars.hpp>
#include <nlohmann/detail/macro_scope.hpp>
#include <nlohmann/detail/meta.hpp>
#include <nlohmann/detail/output/output_adapters.hpp>
#include <nlohmann/detail/value_t.hpp>
#include <nlohmann/detail/output/primitive_serializer.hpp>
namespace nlohmann
{
namespace detail
{
///////////////////
// serialization //
///////////////////
template<typename BasicJsonType>
class fancy_serializer
{
using primitive_serializer_t = primitive_serializer<BasicJsonType>;
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;
static constexpr uint8_t UTF8_ACCEPT = 0;
static constexpr uint8_t UTF8_REJECT = 1;
public:
/*!
@param[in] s output stream to serialize to
@param[in] ichar indentation character to use
*/
fancy_serializer(output_adapter_t<char> s, const char ichar)
: o(std::move(s)), indent_char(ichar), indent_string(512, indent_char)
{}
// delete because of pointer members
fancy_serializer(const fancy_serializer&) = delete;
fancy_serializer& operator=(const fancy_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('\"');
prim_serializer.dump_escaped(*o, 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('\"');
prim_serializer.dump_escaped(*o, 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('\"');
prim_serializer.dump_escaped(*o, 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('\"');
prim_serializer.dump_escaped(*o, 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('\"');
prim_serializer.dump_escaped(*o, *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:
{
prim_serializer.dump_integer(*o, val.m_value.number_integer);
return;
}
case value_t::number_unsigned:
{
prim_serializer.dump_integer(*o, val.m_value.number_unsigned);
return;
}
case value_t::number_float:
{
prim_serializer.dump_float(*o, val.m_value.number_float);
return;
}
case value_t::discarded:
{
o->write_characters("<discarded>", 11);
return;
}
case value_t::null:
{
o->write_characters("null", 4);
return;
}
}
}
private:
/// the output of the fancy_serializer
output_adapter_t<char> o = nullptr;
/// the indentation character
const char indent_char;
/// the indentation string
string_t indent_string;
/// Used for serializing "base" objects. Strings are sort of
/// counted in this, but not completely.
primitive_serializer_t prim_serializer;
};
}
template<typename BasicJsonType>
std::ostream& fancy_dump(std::ostream& o, const BasicJsonType& j)
{
// do the actual serialization
detail::fancy_serializer<BasicJsonType> s(detail::output_adapter<char>(o), o.fill());
s.dump(j, false, false, 0u);
return o;
}
}