foundationdb/fdbclient/json_spirit/json_spirit_writer_template.h

312 lines
7.0 KiB
C++

#ifndef JSON_SPIRIT_WRITER_TEMPLATE
#define JSON_SPIRIT_WRITER_TEMPLATE
// Copyright John W. Wilkinson 2007 - 2014
// Distributed under the MIT License, see accompanying file LICENSE-OSS
// json spirit version 4.08
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
#pragma once
#endif
#include "json_spirit_value.h"
#include "json_spirit_writer_options.h"
#include <cassert>
#include <sstream>
#include <iomanip>
#include <boost/io/ios_state.hpp>
namespace json_spirit {
inline char to_hex_char(unsigned int c) {
assert(c <= 0xF);
const char ch = static_cast<char>(c);
if (ch < 10)
return '0' + ch;
return 'A' - 10 + ch;
}
template <class String_type>
String_type non_printable_to_string(unsigned int c) {
String_type result(6, '\\');
result[1] = 'u';
result[5] = to_hex_char(c & 0x000F);
c >>= 4;
result[4] = to_hex_char(c & 0x000F);
c >>= 4;
result[3] = to_hex_char(c & 0x000F);
c >>= 4;
result[2] = to_hex_char(c & 0x000F);
return result;
}
template <typename Char_type, class String_type>
bool add_esc_char(Char_type c, String_type& s) {
switch (c) {
case '"':
s += to_str<String_type>("\\\"");
return true;
case '\\':
s += to_str<String_type>("\\\\");
return true;
case '\b':
s += to_str<String_type>("\\b");
return true;
case '\f':
s += to_str<String_type>("\\f");
return true;
case '\n':
s += to_str<String_type>("\\n");
return true;
case '\r':
s += to_str<String_type>("\\r");
return true;
case '\t':
s += to_str<String_type>("\\t");
return true;
}
return false;
}
template <class String_type>
String_type add_esc_chars(const String_type& s, bool raw_utf8, bool esc_nonascii) {
typedef typename String_type::const_iterator Iter_type;
typedef typename String_type::value_type Char_type;
String_type result;
const Iter_type end(s.end());
for (Iter_type i = s.begin(); i != end; ++i) {
const Char_type c(*i);
if (add_esc_char(c, result))
continue;
if (raw_utf8) {
result += c;
} else {
const wint_t unsigned_c((c >= 0) ? c : 256 + c);
if (!esc_nonascii && iswprint(unsigned_c)) {
result += c;
} else {
result += non_printable_to_string<String_type>(unsigned_c);
}
}
}
return result;
}
// this class generates the JSON text,
// it keeps track of the indentation level etc.
//
template <class Value_type, class Ostream_type>
class Generator {
typedef typename Value_type::Config_type Config_type;
typedef typename Config_type::String_type String_type;
typedef typename Config_type::Object_type Object_type;
typedef typename Config_type::Array_type Array_type;
typedef typename String_type::value_type Char_type;
typedef typename Object_type::value_type Obj_member_type;
public:
Generator(const Value_type& value, Ostream_type& os, int options, unsigned int precision_of_doubles)
: os_(os), indentation_level_(0), pretty_((options & pretty_print) != 0 || (options & single_line_arrays) != 0),
raw_utf8_((options & raw_utf8) != 0), esc_nonascii_((options & always_escape_nonascii) != 0),
single_line_arrays_((options & single_line_arrays) != 0), ios_saver_(os) {
if (precision_of_doubles > 0) {
precision_of_doubles_ = precision_of_doubles;
} else {
precision_of_doubles_ = (options & remove_trailing_zeros) != 0 ? 16 : 17;
}
output(value);
}
private:
void output(const Value_type& value) {
switch (value.type()) {
case obj_type:
output(value.get_obj());
break;
case array_type:
output(value.get_array());
break;
case str_type:
output(value.get_str());
break;
case bool_type:
output(value.get_bool());
break;
case real_type:
output(value.get_real());
break;
case int_type:
output_int(value);
break;
case null_type:
os_ << "null";
break;
default:
assert(false);
}
}
void output(const Object_type& obj) { output_array_or_obj(obj, '{', '}'); }
void output(const Obj_member_type& member) {
output(Config_type::get_name(member));
space();
os_ << ':';
space();
output(Config_type::get_value(member));
}
void output_int(const Value_type& value) {
if (value.is_uint64()) {
os_ << value.get_uint64();
} else {
os_ << value.get_int64();
}
}
void output(const String_type& s) { os_ << '"' << add_esc_chars(s, raw_utf8_, esc_nonascii_) << '"'; }
void output(bool b) { os_ << to_str<String_type>(b ? "true" : "false"); }
void output(double d) { os_ << std::setprecision(precision_of_doubles_) << d; }
static bool contains_composite_elements(const Array_type& arr) {
for (typename Array_type::const_iterator i = arr.begin(); i != arr.end(); ++i) {
const Value_type& val = *i;
if (val.type() == obj_type || val.type() == array_type) {
return true;
}
}
return false;
}
template <class Iter>
void output_composite_item(Iter i, Iter last) {
output(*i);
if (++i != last) {
os_ << ',';
}
}
void output(const Array_type& arr) {
if (single_line_arrays_ && !contains_composite_elements(arr)) {
os_ << '[';
space();
for (typename Array_type::const_iterator i = arr.begin(); i != arr.end(); ++i) {
output_composite_item(i, arr.end());
space();
}
os_ << ']';
} else {
output_array_or_obj(arr, '[', ']');
}
}
template <class T>
void output_array_or_obj(const T& t, Char_type start_char, Char_type end_char) {
os_ << start_char;
new_line();
++indentation_level_;
for (typename T::const_iterator i = t.begin(); i != t.end(); ++i) {
indent();
output_composite_item(i, t.end());
new_line();
}
--indentation_level_;
indent();
os_ << end_char;
}
void indent() {
if (!pretty_)
return;
for (int i = 0; i < indentation_level_; ++i) {
os_ << " ";
}
}
void space() {
if (pretty_)
os_ << ' ';
}
void new_line() {
if (pretty_)
os_ << '\n';
}
Generator& operator=(const Generator&); // to prevent "assignment operator could not be generated" warning
Ostream_type& os_;
int indentation_level_;
bool pretty_;
bool raw_utf8_;
bool esc_nonascii_;
bool single_line_arrays_;
int precision_of_doubles_;
boost::io::basic_ios_all_saver<Char_type>
ios_saver_; // so that ostream state is reset after control is returned to the caller
};
// writes JSON Value to a stream, e.g.
//
// write_stream( value, os, pretty_print );
//
template <class Value_type, class Ostream_type>
void write_stream(const Value_type& value,
Ostream_type& os,
int options = none,
unsigned int precision_of_doubles = 0) {
os << std::dec;
Generator<Value_type, Ostream_type>(value, os, options, precision_of_doubles);
}
// writes JSON Value to a stream, e.g.
//
// const string json_str = write( value, pretty_print );
//
template <class Value_type>
typename Value_type::String_type write_string(const Value_type& value,
int options = none,
unsigned int precision_of_doubles = 0) {
typedef typename Value_type::String_type::value_type Char_type;
std::basic_ostringstream<Char_type> os;
write_stream(value, os, options, precision_of_doubles);
return os.str();
}
} // namespace json_spirit
#endif