libreoffice-online/common/JsonUtil.hpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#pragma once
#include <cstddef>
#include <set>
#include <string>
#include <Poco/JSON/Object.h>
#include <Poco/JSON/Parser.h>
#include <Log.hpp>
#include <JsonUtil.hpp>
namespace JsonUtil
{
// Parse the json string and fill the Poco::JSON object
// Returns true if parsing successful otherwise false
inline bool parseJSON(const std::string& json, Poco::JSON::Object::Ptr& object)
{
bool success = false;
const size_t index = json.find_first_of('{');
if (index != std::string::npos)
{
const std::string stringJSON = json.substr(index);
Poco::JSON::Parser parser;
const Poco::Dynamic::Var result = parser.parse(stringJSON);
object = result.extract<Poco::JSON::Object::Ptr>();
success = true;
}
return success;
}
inline
int getLevenshteinDist(const std::string& string1, const std::string& string2)
{
int matrix[string1.size() + 1][string2.size() + 1];
std::memset(matrix, 0, sizeof(matrix[0][0]) * (string1.size() + 1) * (string2.size() + 1));
for (size_t i = 0; i < string1.size() + 1; i++)
{
for (size_t j = 0; j < string2.size() + 1; j++)
{
if (i == 0)
{
matrix[i][j] = j;
}
else if (j == 0)
{
matrix[i][j] = i;
}
else if (string1[i - 1] == string2[j - 1])
{
matrix[i][j] = matrix[i - 1][j - 1];
}
else
{
matrix[i][j] = 1 + std::min(std::min(matrix[i][j - 1], matrix[i - 1][j]),
matrix[i - 1][j - 1]);
}
}
}
return matrix[string1.size()][string2.size()];
}
// Gets value for `key` directly from the given JSON in `object`
template <typename T>
T getJSONValue(const Poco::JSON::Object::Ptr &object, const std::string& key)
{
try
{
const Poco::Dynamic::Var valueVar = object->get(key);
return valueVar.convert<T>();
}
catch (const Poco::Exception& exc)
{
LOG_ERR("getJSONValue for [" << key << "]: " << exc.displayText() <<
(exc.nested() ? " (" + exc.nested()->displayText() + ")" : ""));
}
return T();
}
/// Function that searches `object` for `key` and warns if there are minor mis-spellings involved.
/// Upon successful search, fills `value` with value found in object.
/// Removes the entry from the JSON object if @bRemove == true.
template <typename T>
bool findJSONValue(Poco::JSON::Object::Ptr &object, const std::string& key, T& value, bool bRemove = true)
{
std::string keyLower(key);
std::transform(begin(key), end(key), begin(keyLower), ::tolower);
std::vector<std::string> propertyNames;
object->getNames(propertyNames);
// Check each property name against given key
// and warn for mis-spells with tolerance of 2.
for (const std::string& userInput : propertyNames)
{
if (key != userInput)
{
std::string userInputLower(userInput);
std::transform(begin(userInput), end(userInput), begin(userInputLower), ::tolower);
// Mis-spelling tolerance.
const int levDist = getLevenshteinDist(keyLower, userInputLower);
if (levDist > 2)
continue; // Not even close, keep searching.
// We found something with some differences--warn and return.
LOG_WRN("Incorrect JSON property [" << userInput << "]. Did you mean [" << key <<
"] ? (Levenshtein distance: " << levDist << ")");
// Fail without exact match.
return false;
}
value = getJSONValue<T>(object, userInput);
if (bRemove)
object->remove(userInput);
LOG_TRC("Found JSON property [" << userInput << "] => [" << value << "]");
return true;
}
LOG_INF("Missing JSON property [" << key << "] will default to [" << value << "].");
return false;
}
} // end namespace JsonUtil
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */