libkiwix/src/tools/regexTools.cpp

78 lines
2.5 KiB
C++

/*
* Copyright 2011 Emmanuel Engelhart <kelson@kiwix.org>
*
* This program 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
* 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 General Public License for more details.
*
* You should have received a copy of the GNU 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 <tools/regexTools.h>
#include <unicode/regex.h>
#include <unicode/ucnv.h>
#include <memory>
#include <map>
#include <stdexcept>
#include <mutex>
std::map<std::string, std::shared_ptr<icu::RegexPattern>> regexCache;
static std::mutex regexLock;
std::unique_ptr<icu::RegexMatcher> buildMatcher(const std::string& regex, icu::UnicodeString& content)
{
std::shared_ptr<icu::RegexPattern> pattern;
/* Regex is in cache */
try {
pattern = regexCache.at(regex);
} catch (std::out_of_range&) {
// Redo the search with a lock to avoid race condition.
std::lock_guard<std::mutex> l(regexLock);
try {
pattern = regexCache.at(regex);
} catch (std::out_of_range&) {
UErrorCode status = U_ZERO_ERROR;
UParseError pe;
icu::UnicodeString uregex(regex.c_str());
pattern.reset(icu::RegexPattern::compile(uregex, UREGEX_CASE_INSENSITIVE, pe, status));
regexCache[regex] = pattern;
}
}
UErrorCode status = U_ZERO_ERROR;
return std::unique_ptr<icu::RegexMatcher>(pattern->matcher(content, status));
}
bool matchRegex(const std::string& content, const std::string& regex)
{
ucnv_setDefaultName("UTF-8");
icu::UnicodeString ucontent(content.c_str());
auto matcher = buildMatcher(regex, ucontent);
return matcher->find();
}
std::string replaceRegex(const std::string& content,
const std::string& replacement,
const std::string& regex)
{
ucnv_setDefaultName("UTF-8");
icu::UnicodeString ureplacement(replacement.c_str());
icu::UnicodeString ucontent(content.c_str());
auto matcher = buildMatcher(regex, ucontent);
UErrorCode status = U_ZERO_ERROR;
auto uresult = matcher->replaceAll(ureplacement, status);
std::string tmp;
uresult.toUTF8String(tmp);
return tmp;
}