solidity/libdevcore/JSON.cpp

/*
	This file is part of solidity.

	solidity is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	solidity 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 General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file JSON.cpp
 * @author Alexander Arlt <alexander.arlt@arlt-labs.com>
 * @date 2018
 */

#include "JSON.h"

#include <sstream>
#include <map>
#include <memory>

using namespace std;

static_assert(
	(JSONCPP_VERSION_MAJOR == 1) && (JSONCPP_VERSION_MINOR == 7) && (JSONCPP_VERSION_PATCH == 7),
	"Unexpected jsoncpp version: " JSONCPP_VERSION_STRING ". Expecting 1.7.7."
);

namespace dev
{

namespace
{

/// StreamWriterBuilder that can be constructed with specific settings
class StreamWriterBuilder: public Json::StreamWriterBuilder
{
public:
	explicit StreamWriterBuilder(map<string, string> const& _settings)
	{
		for (auto const& iter :_settings)
			this->settings_[iter.first] = iter.second;
	}
};

/// CharReaderBuilder with strict-mode settings
class StrictModeCharReaderBuilder: public Json::CharReaderBuilder
{
public:
	StrictModeCharReaderBuilder()
	{
		Json::CharReaderBuilder::strictMode(&this->settings_);
	}
};

/// Serialise the JSON object (@a _input) with specific builder (@a _builder)
/// \param _input JSON input string
/// \param _builder StreamWriterBuilder that is used to create new Json::StreamWriter
/// \return serialized json object
string print(Json::Value const& _input, Json::StreamWriterBuilder const& _builder)
{
	stringstream stream;
	unique_ptr<Json::StreamWriter> writer(_builder.newStreamWriter());
	writer->write(_input, &stream);
	return stream.str();
}

/// Parse a JSON string (@a _input) with specified builder (@ _builder) and writes resulting JSON object to (@a _json)
/// \param _builder CharReaderBuilder that is used to create new Json::CharReaders
/// \param _input JSON input string
/// \param _json [out] resulting JSON object
/// \param _errs [out] Formatted error messages
/// \return \c true if the document was successfully parsed, \c false if an error occurred.
bool parse(Json::CharReaderBuilder& _builder, string const& _input, Json::Value& _json, string* _errs)
{
	unique_ptr<Json::CharReader> reader(_builder.newCharReader());
	return reader->parse(_input.c_str(), _input.c_str() + _input.length(), &_json, _errs);
}

} // end anonymous namespace

string jsonPrettyPrint(Json::Value const& _input)
{
	static map<string, string> settings{{"indentation", "  "}};
	static StreamWriterBuilder writerBuilder(settings);
	return print(_input, writerBuilder);
}

string jsonCompactPrint(Json::Value const& _input)
{
	static map<string, string> settings{{"indentation", ""}};
	static StreamWriterBuilder writerBuilder(settings);
	return print(_input, writerBuilder);
}

bool jsonParseStrict(string const& _input, Json::Value& _json, string* _errs /* = nullptr */)
{
	static StrictModeCharReaderBuilder readerBuilder;
	return parse(readerBuilder, _input, _json, _errs);
}

bool jsonParse(string const& _input, Json::Value& _json, string *_errs /* = nullptr */)
{
	static Json::CharReaderBuilder readerBuilder;
	return parse(readerBuilder, _input, _json, _errs);
}

} // namespace dev