Files
Xenia-Canary/src/xenia/base/filesystem_wildcard.cc

117 lines
3.2 KiB
C++

/**
******************************************************************************
* Xenia : Xbox 360 Emulator Research Project *
******************************************************************************
* Copyright 2015 Ben Vanik. All rights reserved. *
* Released under the BSD license - see LICENSE in the root for more details. *
******************************************************************************
*/
#include "xenia/base/filesystem_wildcard.h"
#include "xenia/base/assert.h"
#include <algorithm>
namespace xe {
namespace filesystem {
WildcardFlags WildcardFlags::FIRST(true, false, false);
WildcardFlags WildcardFlags::LAST(false, true, false);
WildcardFlags WildcardFlags::ANY(false, false, true);
WildcardFlags::WildcardFlags()
: FromStart(false), ToEnd(false), ExactLength(false) {}
WildcardFlags::WildcardFlags(bool start, bool end, bool exact_length)
: FromStart(start), ToEnd(end), ExactLength(exact_length) {}
WildcardRule::WildcardRule(const std::string& str_match,
const WildcardFlags& flags)
: match(str_match), rules(flags) {
std::transform(match.begin(), match.end(), match.begin(), tolower);
}
bool WildcardRule::Check(const std::string& str_lower,
std::string::size_type* offset) const {
if (match.empty()) {
return true;
}
if ((str_lower.size() - *offset) < match.size()) {
return false;
}
if (rules.ExactLength) {
*offset += match.size();
return true;
}
std::string::size_type result(str_lower.find(match, *offset));
if (result != std::string::npos) {
if (rules.FromStart && result != *offset) {
return false;
}
if (rules.ToEnd && result != (str_lower.size() - match.size())) {
return false;
}
*offset = (result + match.size());
return true;
}
return false;
}
void WildcardEngine::PreparePattern(const std::string& pattern) {
rules.clear();
WildcardFlags flags(WildcardFlags::FIRST);
size_t n = 0;
size_t last = 0;
while ((n = pattern.find_first_of("*?", last)) != pattern.npos) {
if (last != n) {
std::string str_str(pattern.substr(last, n - last));
rules.push_back(WildcardRule(str_str, flags));
}
if (pattern[n] == '?') {
auto end = pattern.find_first_not_of('?', n + 1);
auto count = end == pattern.npos ? (pattern.size() - n) : (end - n);
rules.push_back(
WildcardRule(pattern.substr(n, count), WildcardFlags::ANY));
last = n + count;
} else if (pattern[n] == '*') {
last = n + 1;
} else {
assert_always();
}
flags = WildcardFlags();
}
if (last != pattern.size()) {
std::string str_str(pattern.substr(last));
rules.push_back(WildcardRule(str_str, WildcardFlags::LAST));
}
}
void WildcardEngine::SetRule(const std::string& pattern) {
PreparePattern(pattern);
}
bool WildcardEngine::Match(const std::string& str) const {
std::string str_lc;
std::transform(str.begin(), str.end(), std::back_inserter(str_lc), tolower);
std::string::size_type offset(0);
for (const auto& rule : rules) {
if (!(rule.Check(str_lc, &offset))) {
return false;
}
}
return true;
}
} // namespace filesystem
} // namespace xe