Files
filament/libs/utils/src/Path.cpp

311 lines
7.8 KiB
C++

/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <utils/Path.h>
#include <sstream>
#include <ostream>
#include <iterator>
#if defined(WIN32)
# include <utils/compiler.h>
# include <utils/win32/stdtypes.h>
# define SEPARATOR '\\'
# define SEPARATOR_STR "\\"
#else
# include <unistd.h>
# define SEPARATOR '/'
# define SEPARATOR_STR "/"
#endif
#include <limits.h>
#include <sys/stat.h>
namespace utils {
Path::Path(const char* path)
: Path(std::string(path)) {
}
Path::Path(std::string_view pathname)
: Path(std::string(pathname)) {
}
Path::Path(const std::string& path)
: m_path(getCanonicalPath(path)) {
}
bool Path::exists() const {
#if defined(_WIN64) || defined(_M_X64)
struct _stat64 file;
return _stat64(c_str(), &file) == 0;
#else
struct stat file;
return stat(c_str(), &file) == 0;
#endif
}
bool Path::isFile() const {
struct stat file;
if (stat(c_str(), &file) == 0) {
return S_ISREG(file.st_mode);
}
return false;
}
bool Path::isDirectory() const {
struct stat file;
if (stat(c_str(), &file) == 0) {
return S_ISDIR(file.st_mode);
}
return false;
}
Path Path::concat(const Path& path) const {
if (path.isEmpty()) return *this;
if (path.isAbsolute()) return path;
// std::string::back() is UB if the string is empty, so we rely on short-circuit evaluation
if (!m_path.empty() && m_path.back() != SEPARATOR) {
return Path(m_path + SEPARATOR + path.getPath());
}
return Path(m_path + path.getPath());
}
void Path::concatToSelf(const Path& path) {
if (!path.isEmpty()) {
if (path.isAbsolute()) {
m_path = path.getPath();
// std::string::back() is UB if the string is empty, so we rely on short-circuit evaluation
} else if (!m_path.empty() && m_path.back() != SEPARATOR) {
m_path = getCanonicalPath(m_path + SEPARATOR + path.getPath());
} else {
m_path = getCanonicalPath(m_path + path.getPath());
}
}
}
Path Path::concat(const std::string& root, const std::string& leaf) {
return Path(root).concat(Path(leaf));
}
Path Path::getCurrentDirectory() {
char directory[PATH_MAX + 1];
if (getcwd(directory, PATH_MAX) == nullptr) {
return Path();
}
return Path(directory);
}
Path Path::getAbsolutePath() const {
if (isEmpty() || isAbsolute()) {
return *this;
}
return getCurrentDirectory().concat(*this);
}
#if !defined(WIN32)
bool Path::isAbsolute() const {
return !isEmpty() && m_path.front() == '/';
}
#endif
Path Path::getParent() const {
if (isEmpty()) return "";
std::string result;
std::vector<std::string> segments(split());
// if our path is absolute with a single segment,
// be sure to keep the prefix component
if (!isAbsolute() || segments.size() > 1) {
segments.pop_back(); // peel the last one
}
for (auto const& s : segments) {
result.append(s).append(SEPARATOR_STR);
}
return getCanonicalPath(result);
}
Path Path::getAncestor(int n) const {
Path result = getParent();
while (n--) {
result = result.getParent();
}
return result;
}
std::string Path::getName() const {
if (isEmpty()) return "";
std::vector<std::string> segments(split());
return segments.back();
}
std::string Path::getExtension() const {
if (isEmpty() || isDirectory()) {
return "";
}
auto name = getName();
auto index = name.rfind('.');
if (index != std::string::npos && index != 0) {
return name.substr(index + 1);
} else {
return "";
}
}
std::string Path::getNameWithoutExtension() const {
std::string name = getName();
size_t index = name.rfind('.');
if (index != std::string::npos) {
return name.substr(0, index);
}
return name;
}
std::ostream& operator<<(std::ostream& os, const Path& path) {
os << path.getPath();
return os;
}
std::vector<std::string> Path::split() const {
std::vector<std::string> segments;
if (isEmpty()) return segments;
size_t current;
ssize_t next = -1;
// If there is a leading disk designator such as C:, this naturally becomes the first segment.
// However if there there is leading slash or back slash, we need to explicitly preserve it.
// Note that we are guaranteed to have at least one char in the path at this point.
if (m_path[0] == '/' || m_path[0] == '\\') {
segments.push_back(m_path.substr(0, 1));
next = 0;
}
do {
current = size_t(next + 1);
next = m_path.find_first_of(SEPARATOR, current);
std::string segment(m_path.substr(current, next - current));
if (!segment.empty()) segments.push_back(segment);
} while (next != std::string::npos);
if (segments.empty()) segments.push_back(m_path);
return segments;
}
std::string Path::getCanonicalPath(const std::string& path) {
if (path.empty()) return "";
std::vector<std::string> segments;
// If the path starts with a / we must preserve it
bool starts_with_slash = path.front() == SEPARATOR;
// If the path does not end with a / we need to remove the
// extra / added by the join process
bool ends_with_slash = path.back() == SEPARATOR;
size_t current;
ssize_t next = -1;
do {
current = size_t(next + 1);
// Handle both Unix and Windows style separators
next = path.find_first_of("/\\", current);
std::string segment(path.substr(current, next - current));
size_t size = segment.length();
// skip empty (keep initial)
if (size == 0 && !segments.empty()) {
continue;
}
// skip . (keep initial)
if (segment == "." && !segments.empty()) {
continue;
}
// remove ..
if (segment == ".." && !segments.empty()) {
if (segments.back().empty()) { // ignore if .. follows initial /
continue;
}
if (segments.back() != "..") {
segments.pop_back();
continue;
}
}
segments.push_back(segment);
} while (next != std::string::npos);
// Join the vector as a single string, every element is
// separated by a '/'. This process adds an extra / at
// the end that might need to be removed
std::stringstream clean_path;
std::copy(segments.begin(), segments.end(),
std::ostream_iterator<std::string>(clean_path, SEPARATOR_STR));
std::string new_path = clean_path.str();
if (starts_with_slash && new_path.empty()) {
new_path = SEPARATOR_STR;
}
if (!ends_with_slash && new_path.length() > 1) {
new_path.pop_back();
}
return new_path;
}
bool Path::mkdirRecursive() const {
if (isEmpty()) {
return true;
}
errno = 0;
bool success = mkdir();
if (!success) {
int saveErrno = errno;
switch (saveErrno) {
case EEXIST: {
bool result = isDirectory();
errno = saveErrno;
return result;
}
case ENOENT:
getParent().mkdirRecursive();
return mkdir();
default:
break;
}
}
return success;
}
bool Path::unlinkFile() {
return ::unlink(m_path.c_str()) == 0;
}
} // namespace utils