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#include <sys/time.h>
#include <filesystem>
#include "util.hh"
#include "types.hh"
namespace fs = std::filesystem;
namespace nix {
void createSymlink(const Path & target, const Path & link,
std::optional<time_t> mtime)
{
if (symlink(target.c_str(), link.c_str()))
throw SysError("creating symlink from '%1%' to '%2%'", link, target);
if (mtime) {
struct timeval times[2];
times[0].tv_sec = *mtime;
times[0].tv_usec = 0;
times[1].tv_sec = *mtime;
times[1].tv_usec = 0;
if (lutimes(link.c_str(), times))
throw SysError("setting time of symlink '%s'", link);
}
}
void replaceSymlink(const Path & target, const Path & link,
std::optional<time_t> mtime)
{
for (unsigned int n = 0; true; n++) {
Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link)));
try {
createSymlink(target, tmp, mtime);
} catch (SysError & e) {
if (e.errNo == EEXIST) continue;
throw;
}
moveFile(tmp, link);
break;
}
}
void setWriteTime(const fs::path & p, const struct stat & st)
{
struct timeval times[2];
times[0] = {
.tv_sec = st.st_atime,
.tv_usec = 0,
};
times[1] = {
.tv_sec = st.st_mtime,
.tv_usec = 0,
};
warn("Setting the mtime of %s to %d", p.c_str(), st.st_mtim.tv_sec);
if (lutimes(p.c_str(), times) != 0)
throw SysError("changing modification time of '%s'", p);
}
void copy(const fs::directory_entry & from, const fs::path & to, bool andDelete)
{
// TODO: Rewrite the `is_*` to use `symlink_status()`
auto statOfFrom = lstat(from.path().c_str());
auto fromStatus = from.symlink_status();
// Mark the directory as writable so that we can delete its children
if (andDelete && fs::is_directory(fromStatus)) {
fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow);
}
if (fs::is_symlink(fromStatus) || fs::is_regular_file(fromStatus)) {
fs::copy(from.path(), to, fs::copy_options::copy_symlinks | fs::copy_options::overwrite_existing);
} else if (fs::is_directory(fromStatus)) {
fs::create_directory(to);
for (auto & entry : fs::directory_iterator(from.path())) {
copy(entry, to / entry.path().filename(), andDelete);
}
} else {
throw Error("file '%s' has an unsupported type", from.path());
}
setWriteTime(to, statOfFrom);
if (andDelete) {
if (!fs::is_symlink(fromStatus))
fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow);
fs::remove(from.path());
}
}
void moveFile(const Path & oldName, const Path & newName)
{
auto oldPath = fs::path(oldName);
auto newPath = fs::path(newName);
try {
fs::rename(oldPath, newPath);
} catch (fs::filesystem_error & e) {
if (e.code().value() == EXDEV) {
fs::remove(newPath);
warn("Copying %s to %s", oldName, newName);
copy(fs::directory_entry(oldPath), newPath, true);
}
}
}
}
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