minetest/src/util/serialize.cpp

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/*
2013-02-24 18:40:43 +01:00
Minetest
Copyright (C) 2010-2012 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "serialize.h"
#include <sstream>
#include <iomanip>
// Creates a string encoded in JSON format (almost equivalent to a C string literal)
std::string serializeJsonString(const std::string &plain)
{
std::ostringstream os(std::ios::binary);
os<<"\"";
for(size_t i = 0; i < plain.size(); i++)
{
char c = plain[i];
switch(c)
{
case '"': os<<"\\\""; break;
case '\\': os<<"\\\\"; break;
case '/': os<<"\\/"; break;
case '\b': os<<"\\b"; break;
case '\f': os<<"\\f"; break;
case '\n': os<<"\\n"; break;
case '\r': os<<"\\r"; break;
case '\t': os<<"\\t"; break;
default:
{
if(c >= 32 && c <= 126)
{
os<<c;
}
else
{
u32 cnum = (u32) (u8) c;
os<<"\\u"<<std::hex<<std::setw(4)<<std::setfill('0')<<cnum;
}
break;
}
}
}
os<<"\"";
return os.str();
}
// Reads a string encoded in JSON format
std::string deSerializeJsonString(std::istream &is)
{
std::ostringstream os(std::ios::binary);
char c, c2;
// Parse initial doublequote
is >> c;
if(c != '"')
throw SerializationError("JSON string must start with doublequote");
// Parse characters
for(;;)
{
c = is.get();
if(is.eof())
throw SerializationError("JSON string ended prematurely");
if(c == '"')
{
return os.str();
}
else if(c == '\\')
{
c2 = is.get();
if(is.eof())
throw SerializationError("JSON string ended prematurely");
switch(c2)
{
default: os<<c2; break;
case 'b': os<<'\b'; break;
case 'f': os<<'\f'; break;
case 'n': os<<'\n'; break;
case 'r': os<<'\r'; break;
case 't': os<<'\t'; break;
case 'u':
{
char hexdigits[4+1];
is.read(hexdigits, 4);
if(is.eof())
throw SerializationError("JSON string ended prematurely");
hexdigits[4] = 0;
std::istringstream tmp_is(hexdigits, std::ios::binary);
int hexnumber;
tmp_is >> std::hex >> hexnumber;
os<<((char)hexnumber);
break;
}
}
}
else
{
os<<c;
}
}
return os.str();
}