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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2013-2017 Regents of the University of California.
*
* This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
*
* ndn-cxx library 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 3 of the License, or (at your option) any later version.
*
* ndn-cxx library 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 copies of the GNU General Public License and GNU Lesser
* General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
* <http://www.gnu.org/licenses/>.
*
* See AUTHORS.md for complete list of ndn-cxx authors and contributors.
*
* @author Yingdi Yu <http://irl.cs.ucla.edu/~yingdi/>
*/
#include "regex-repeat-matcher.hpp"
#include "regex-backref-matcher.hpp"
#include "regex-component-set-matcher.hpp"
#include <boost/regex.hpp>
#include <cstdlib>
namespace ndn {
RegexRepeatMatcher::RegexRepeatMatcher(const std::string& expr,
shared_ptr<RegexBackrefManager> backrefManager,
size_t indicator)
: RegexMatcher(expr, EXPR_REPEAT_PATTERN, std::move(backrefManager))
, m_indicator(indicator)
{
compile();
}
void
RegexRepeatMatcher::compile()
{
if ('(' == m_expr[0]) {
auto matcher = make_shared<RegexBackrefMatcher>(m_expr.substr(0, m_indicator), m_backrefManager);
m_backrefManager->pushRef(matcher);
matcher->lateCompile();
m_matchers.push_back(std::move(matcher));
}
else {
m_matchers.push_back(make_shared<RegexComponentSetMatcher>(m_expr.substr(0, m_indicator),
m_backrefManager));
}
parseRepetition();
}
bool
RegexRepeatMatcher::parseRepetition()
{
size_t exprSize = m_expr.size();
const size_t MAX_REPETITIONS = std::numeric_limits<size_t>::max();
if (exprSize == m_indicator) {
m_repeatMin = 1;
m_repeatMax = 1;
return true;
}
if (exprSize == (m_indicator + 1)) {
if ('?' == m_expr[m_indicator]) {
m_repeatMin = 0;
m_repeatMax = 1;
return true;
}
if ('+' == m_expr[m_indicator]) {
m_repeatMin = 1;
m_repeatMax = MAX_REPETITIONS;
return true;
}
if ('*' == m_expr[m_indicator]) {
m_repeatMin = 0;
m_repeatMax = MAX_REPETITIONS;
return true;
}
}
else {
std::string repeatStruct = m_expr.substr(m_indicator, exprSize - m_indicator);
size_t rsSize = repeatStruct.size();
size_t min = 0;
size_t max = 0;
if (boost::regex_match(repeatStruct, boost::regex("\\{[0-9]+,[0-9]+\\}"))) {
size_t separator = repeatStruct.find_first_of(',', 0);
min = std::atoi(repeatStruct.substr(1, separator - 1).data());
max = std::atoi(repeatStruct.substr(separator + 1, rsSize - separator - 2).data());
}
else if (boost::regex_match(repeatStruct, boost::regex("\\{,[0-9]+\\}"))) {
size_t separator = repeatStruct.find_first_of(',', 0);
min = 0;
max = std::atoi(repeatStruct.substr(separator + 1, rsSize - separator - 2).data());
}
else if (boost::regex_match(repeatStruct, boost::regex("\\{[0-9]+,\\}"))) {
size_t separator = repeatStruct.find_first_of(',', 0);
min = std::atoi(repeatStruct.substr(1, separator).data());
max = MAX_REPETITIONS;
}
else if (boost::regex_match(repeatStruct, boost::regex("\\{[0-9]+\\}"))) {
min = std::atoi(repeatStruct.substr(1, rsSize - 1).data());
max = min;
}
else
BOOST_THROW_EXCEPTION(Error(std::string("Error: RegexRepeatMatcher.ParseRepetition():")
+ " Unrecognized format " + m_expr));
if (min > MAX_REPETITIONS || max > MAX_REPETITIONS || min > max)
BOOST_THROW_EXCEPTION(Error(std::string("Error: RegexRepeatMatcher.ParseRepetition():")
+ " Wrong number " + m_expr));
m_repeatMin = min;
m_repeatMax = max;
return true;
}
return false;
}
bool
RegexRepeatMatcher::match(const Name& name, size_t offset, size_t len)
{
m_matchResult.clear();
if (m_repeatMin == 0)
if (len == 0)
return true;
if (recursiveMatch(0, name, offset, len)) {
for (size_t i = offset; i < offset + len; i++)
m_matchResult.push_back(name.get(i));
return true;
}
return false;
}
bool
RegexRepeatMatcher::recursiveMatch(size_t repeat, const Name& name, size_t offset, size_t len)
{
ssize_t tried = len;
if (0 < len && repeat >= m_repeatMax) {
return false;
}
if (0 == len && repeat < m_repeatMin) {
return false;
}
if (0 == len && repeat >= m_repeatMin) {
return true;
}
auto matcher = m_matchers[0];
while (tried >= 0) {
if (matcher->match(name, offset, tried) &&
recursiveMatch(repeat + 1, name, offset + tried, len - tried))
return true;
tried--;
}
return false;
}
} // namespace ndn