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util.{hh,cc}: Split out file-system.{hh,cc}

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Change-Id: Ifa89a529e7e34e7291eca87d802d2f569cf2493e
This commit is contained in:
Tom Hubrecht 2024-05-28 11:52:13 +02:00
parent 81bdf8d2d6
commit 6b5078c815
24 changed files with 974 additions and 919 deletions
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1
src/libstore/build/hook-instance.cc
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@ -1,3 +1,4 @@
#include "file-system.hh"
#include "globals.hh"
#include "hook-instance.hh"

1
src/libstore/crypto.cc
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@ -1,5 +1,6 @@
#include "crypto.hh"
#include "util.hh"
#include "file-system.hh"
#include "globals.hh"
#include <sodium.h>

1
src/libstore/lock.cc
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@ -1,4 +1,5 @@
#include "lock.hh"
#include "file-system.hh"
#include "globals.hh"
#include "pathlocks.hh"

1
src/libstore/ssh.hh
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@ -1,6 +1,7 @@
#pragma once
///@file
#include "file-system.hh"
#include "util.hh"
#include "sync.hh"

1
src/libutil/archive.cc
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@ -12,6 +12,7 @@
#include <fcntl.h>
#include "archive.hh"
#include "file-system.hh"
#include "util.hh"
#include "config.hh"
#include "signals.hh"

1
src/libutil/archive.hh
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@ -3,6 +3,7 @@
#include "types.hh"
#include "serialise.hh"
#include "file-system.hh"
namespace nix {

2
src/libutil/canon-path.cc
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@ -1,5 +1,5 @@
#include "canon-path.hh"
#include "util.hh"
#include "file-system.hh"
namespace nix {

1
src/libutil/cgroup.cc
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@ -2,6 +2,7 @@
#include "cgroup.hh"
#include "util.hh"
#include "file-system.hh"
#include "finally.hh"
#include <chrono>

1
src/libutil/config.cc
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@ -2,6 +2,7 @@
#include "args.hh"
#include "abstract-setting-to-json.hh"
#include "experimental-features.hh"
#include "file-system.hh"
#include "config-impl.hh"

678
src/libutil/file-system.cc Normal file
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#include <sys/time.h>
#include <filesystem>
#include <atomic>
#include "environment-variables.hh"
#include "file-system.hh"
#include "finally.hh"
#include "serialise.hh"
#include "util.hh"
#include "signals.hh"
#include "types.hh"
namespace fs = std::filesystem;
namespace nix {
Path absPath(Path path, std::optional<PathView> dir, bool resolveSymlinks)
{
if (path.empty() || path[0] != '/') {
if (!dir) {
#ifdef __GNU__
/* GNU (aka. GNU/Hurd) doesn't have any limitation on path
lengths and doesn't define `PATH_MAX'. */
char *buf = getcwd(NULL, 0);
if (buf == NULL)
#else
char buf[PATH_MAX];
if (!getcwd(buf, sizeof(buf)))
#endif
throw SysError("cannot get cwd");
path = concatStrings(buf, "/", path);
#ifdef __GNU__
free(buf);
#endif
} else
path = concatStrings(*dir, "/", path);
}
return canonPath(path, resolveSymlinks);
}
Path canonPath(PathView path, bool resolveSymlinks)
{
assert(path != "");
std::string s;
s.reserve(256);
if (path[0] != '/')
throw Error("not an absolute path: '%1%'", path);
std::string temp;
/* Count the number of times we follow a symlink and stop at some
arbitrary (but high) limit to prevent infinite loops. */
unsigned int followCount = 0, maxFollow = 1024;
while (1) {
/* Skip slashes. */
while (!path.empty() && path[0] == '/') path.remove_prefix(1);
if (path.empty()) break;
/* Ignore `.'. */
if (path == "." || path.substr(0, 2) == "./")
path.remove_prefix(1);
/* If `..', delete the last component. */
else if (path == ".." || path.substr(0, 3) == "../")
{
if (!s.empty()) s.erase(s.rfind('/'));
path.remove_prefix(2);
}
/* Normal component; copy it. */
else {
s += '/';
if (const auto slash = path.find('/'); slash == std::string::npos) {
s += path;
path = {};
} else {
s += path.substr(0, slash);
path = path.substr(slash);
}
/* If s points to a symlink, resolve it and continue from there */
if (resolveSymlinks && isLink(s)) {
if (++followCount >= maxFollow)
throw Error("infinite symlink recursion in path '%1%'", path);
temp = concatStrings(readLink(s), path);
path = temp;
if (!temp.empty() && temp[0] == '/') {
s.clear(); /* restart for symlinks pointing to absolute path */
} else {
s = dirOf(s);
if (s == "/") { // we don’t want trailing slashes here, which dirOf only produces if s = /
s.clear();
}
}
}
}
}
return s.empty() ? "/" : std::move(s);
}
void chmodPath(const Path & path, mode_t mode)
{
if (chmod(path.c_str(), mode) == -1)
throw SysError("setting permissions on '%s'", path);
}
Path dirOf(const PathView path)
{
Path::size_type pos = path.rfind('/');
if (pos == std::string::npos)
return ".";
return pos == 0 ? "/" : Path(path, 0, pos);
}
std::string_view baseNameOf(std::string_view path)
{
if (path.empty())
return "";
auto last = path.size() - 1;
if (path[last] == '/' && last > 0)
last -= 1;
auto pos = path.rfind('/', last);
if (pos == std::string::npos)
pos = 0;
else
pos += 1;
return path.substr(pos, last - pos + 1);
}
std::string expandTilde(std::string_view path)
{
// TODO: expand ~user ?
auto tilde = path.substr(0, 2);
if (tilde == "~/" || tilde == "~")
return getHome() + std::string(path.substr(1));
else
return std::string(path);
}
bool isInDir(std::string_view path, std::string_view dir)
{
return path.substr(0, 1) == "/"
&& path.substr(0, dir.size()) == dir
&& path.size() >= dir.size() + 2
&& path[dir.size()] == '/';
}
bool isDirOrInDir(std::string_view path, std::string_view dir)
{
return path == dir || isInDir(path, dir);
}
struct stat stat(const Path & path)
{
struct stat st;
if (stat(path.c_str(), &st))
throw SysError("getting status of '%1%'", path);
return st;
}
struct stat lstat(const Path & path)
{
struct stat st;
if (lstat(path.c_str(), &st))
throw SysError("getting status of '%1%'", path);
return st;
}
std::optional<struct stat> maybeLstat(const Path & path)
{
std::optional<struct stat> st{std::in_place};
if (lstat(path.c_str(), &*st))
{
if (errno == ENOENT || errno == ENOTDIR)
st.reset();
else
throw SysError("getting status of '%s'", path);
}
return st;
}
bool pathExists(const Path & path)
{
return maybeLstat(path).has_value();
}
bool pathAccessible(const Path & path)
{
try {
return pathExists(path);
} catch (SysError & e) {
// swallow EPERM
if (e.errNo == EPERM) return false;
throw;
}
}
Path readLink(const Path & path)
{
checkInterrupt();
std::vector<char> buf;
for (ssize_t bufSize = PATH_MAX/4; true; bufSize += bufSize/2) {
buf.resize(bufSize);
ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize);
if (rlSize == -1)
if (errno == EINVAL)
throw Error("'%1%' is not a symlink", path);
else
throw SysError("reading symbolic link '%1%'", path);
else if (rlSize < bufSize)
return std::string(buf.data(), rlSize);
}
}
bool isLink(const Path & path)
{
struct stat st = lstat(path);
return S_ISLNK(st.st_mode);
}
DirEntries readDirectory(DIR *dir, const Path & path)
{
DirEntries entries;
entries.reserve(64);
struct dirent * dirent;
while (errno = 0, dirent = readdir(dir)) { /* sic */
checkInterrupt();
std::string name = dirent->d_name;
if (name == "." || name == "..") continue;
entries.emplace_back(name, dirent->d_ino,
#ifdef HAVE_STRUCT_DIRENT_D_TYPE
dirent->d_type
#else
DT_UNKNOWN
#endif
);
}
if (errno) throw SysError("reading directory '%1%'", path);
return entries;
}
DirEntries readDirectory(const Path & path)
{
AutoCloseDir dir(opendir(path.c_str()));
if (!dir) throw SysError("opening directory '%1%'", path);
return readDirectory(dir.get(), path);
}
unsigned char getFileType(const Path & path)
{
struct stat st = lstat(path);
if (S_ISDIR(st.st_mode)) return DT_DIR;
if (S_ISLNK(st.st_mode)) return DT_LNK;
if (S_ISREG(st.st_mode)) return DT_REG;
return DT_UNKNOWN;
}
std::string readFile(int fd)
{
struct stat st;
if (fstat(fd, &st) == -1)
throw SysError("statting file");
return drainFD(fd, true, st.st_size);
}
std::string readFile(const Path & path)
{
AutoCloseFD fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)};
if (!fd)
throw SysError("opening file '%1%'", path);
return readFile(fd.get());
}
void readFile(const Path & path, Sink & sink)
{
AutoCloseFD fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)};
if (!fd)
throw SysError("opening file '%s'", path);
drainFD(fd.get(), sink);
}
void writeFile(const Path & path, std::string_view s, mode_t mode, bool sync)
{
AutoCloseFD fd{open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)};
if (!fd)
throw SysError("opening file '%1%'", path);
try {
writeFull(fd.get(), s);
} catch (Error & e) {
e.addTrace({}, "writing file '%1%'", path);
throw;
}
if (sync)
fd.fsync();
// Explicitly close to make sure exceptions are propagated.
fd.close();
if (sync)
syncParent(path);
}
void writeFile(const Path & path, Source & source, mode_t mode, bool sync)
{
AutoCloseFD fd{open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)};
if (!fd)
throw SysError("opening file '%1%'", path);
std::vector<char> buf(64 * 1024);
try {
while (true) {
try {
auto n = source.read(buf.data(), buf.size());
writeFull(fd.get(), {buf.data(), n});
} catch (EndOfFile &) { break; }
}
} catch (Error & e) {
e.addTrace({}, "writing file '%1%'", path);
throw;
}
if (sync)
fd.fsync();
// Explicitly close to make sure exceptions are propagated.
fd.close();
if (sync)
syncParent(path);
}
void syncParent(const Path & path)
{
AutoCloseFD fd{open(dirOf(path).c_str(), O_RDONLY, 0)};
if (!fd)
throw SysError("opening file '%1%'", path);
fd.fsync();
}
static void _deletePath(int parentfd, const Path & path, uint64_t & bytesFreed)
{
checkInterrupt();
std::string name(baseNameOf(path));
struct stat st;
if (fstatat(parentfd, name.c_str(), &st, AT_SYMLINK_NOFOLLOW) == -1) {
if (errno == ENOENT) return;
throw SysError("getting status of '%1%'", path);
}
if (!S_ISDIR(st.st_mode)) {
/* We are about to delete a file. Will it likely free space? */
switch (st.st_nlink) {
/* Yes: last link. */
case 1:
bytesFreed += st.st_size;
break;
/* Maybe: yes, if 'auto-optimise-store' or manual optimisation
was performed. Instead of checking for real let's assume
it's an optimised file and space will be freed.
In worst case we will double count on freed space for files
with exactly two hardlinks for unoptimised packages.
*/
case 2:
bytesFreed += st.st_size;
break;
/* No: 3+ links. */
default:
break;
}
}
if (S_ISDIR(st.st_mode)) {
/* Make the directory accessible. */
const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR;
if ((st.st_mode & PERM_MASK) != PERM_MASK) {
if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1)
throw SysError("chmod '%1%'", path);
}
int fd = openat(parentfd, path.c_str(), O_RDONLY);
if (fd == -1)
throw SysError("opening directory '%1%'", path);
AutoCloseDir dir(fdopendir(fd));
if (!dir)
throw SysError("opening directory '%1%'", path);
for (auto & i : readDirectory(dir.get(), path))
_deletePath(dirfd(dir.get()), path + "/" + i.name, bytesFreed);
}
int flags = S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0;
if (unlinkat(parentfd, name.c_str(), flags) == -1) {
if (errno == ENOENT) return;
throw SysError("cannot unlink '%1%'", path);
}
}
static void _deletePath(const Path & path, uint64_t & bytesFreed)
{
Path dir = dirOf(path);
if (dir == "")
dir = "/";
AutoCloseFD dirfd{open(dir.c_str(), O_RDONLY)};
if (!dirfd) {
if (errno == ENOENT) return;
throw SysError("opening directory '%1%'", path);
}
_deletePath(dirfd.get(), path, bytesFreed);
}
void deletePath(const Path & path)
{
uint64_t dummy;
deletePath(path, dummy);
}
void deletePath(const Path & path, uint64_t & bytesFreed)
{
//Activity act(*logger, lvlDebug, "recursively deleting path '%1%'", path);
bytesFreed = 0;
_deletePath(path, bytesFreed);
}
Paths createDirs(const Path & path)
{
Paths created;
if (path == "/") return created;
struct stat st;
if (lstat(path.c_str(), &st) == -1) {
created = createDirs(dirOf(path));
if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST)
throw SysError("creating directory '%1%'", path);
st = lstat(path);
created.push_back(path);
}
if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1)
throw SysError("statting symlink '%1%'", path);
if (!S_ISDIR(st.st_mode)) throw Error("'%1%' is not a directory", path);
return created;
}
//////////////////////////////////////////////////////////////////////
AutoDelete::AutoDelete() : del{false} {}
AutoDelete::AutoDelete(const std::string & p, bool recursive) : path(p)
{
del = true;
this->recursive = recursive;
}
AutoDelete::~AutoDelete()
{
try {
if (del) {
if (recursive)
deletePath(path);
else {
if (remove(path.c_str()) == -1)
throw SysError("cannot unlink '%1%'", path);
}
}
} catch (...) {
ignoreException();
}
}
void AutoDelete::cancel()
{
del = false;
}
void AutoDelete::reset(const Path & p, bool recursive) {
path = p;
this->recursive = recursive;
del = true;
}
//////////////////////////////////////////////////////////////////////
static Path tempName(Path tmpRoot, const Path & prefix, bool includePid,
std::atomic<unsigned int> & counter)
{
tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true);
if (includePid)
return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++);
else
return fmt("%1%/%2%-%3%", tmpRoot, prefix, counter++);
}
Path createTempDir(const Path & tmpRoot, const Path & prefix,
bool includePid, bool useGlobalCounter, mode_t mode)
{
static std::atomic<unsigned int> globalCounter = 0;
std::atomic<unsigned int> localCounter = 0;
auto & counter(useGlobalCounter ? globalCounter : localCounter);
while (1) {
checkInterrupt();
Path tmpDir = tempName(tmpRoot, prefix, includePid, counter);
if (mkdir(tmpDir.c_str(), mode) == 0) {
#if __FreeBSD__
/* Explicitly set the group of the directory. This is to
work around around problems caused by BSD's group
ownership semantics (directories inherit the group of
the parent). For instance, the group of /tmp on
FreeBSD is "wheel", so all directories created in /tmp
will be owned by "wheel"; but if the user is not in
"wheel", then "tar" will fail to unpack archives that
have the setgid bit set on directories. */
if (chown(tmpDir.c_str(), (uid_t) -1, getegid()) != 0)
throw SysError("setting group of directory '%1%'", tmpDir);
#endif
return tmpDir;
}
if (errno != EEXIST)
throw SysError("creating directory '%1%'", tmpDir);
}
}
std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix)
{
Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX");
// Strictly speaking, this is UB, but who cares...
// FIXME: use O_TMPFILE.
AutoCloseFD fd(mkstemp((char *) tmpl.c_str()));
if (!fd)
throw SysError("creating temporary file '%s'", tmpl);
closeOnExec(fd.get());
return {std::move(fd), tmpl};
}
void createSymlink(const Path & target, const Path & link)
{
if (symlink(target.c_str(), link.c_str()))
throw SysError("creating symlink from '%1%' to '%2%'", link, target);
}
void replaceSymlink(const Path & target, const Path & link)
{
for (unsigned int n = 0; true; n++) {
Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link)));
try {
createSymlink(target, tmp);
} catch (SysError & e) {
if (e.errNo == EEXIST) continue;
throw;
}
renameFile(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,
};
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, CopyFileFlags flags)
{
// 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 (flags.deleteAfter && 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)) {
auto opts = fs::copy_options::overwrite_existing;
if (!flags.followSymlinks) {
opts |= fs::copy_options::copy_symlinks;
}
fs::copy(from.path(), to, opts);
} else if (fs::is_directory(fromStatus)) {
fs::create_directory(to);
for (auto & entry : fs::directory_iterator(from.path())) {
copy(entry, to / entry.path().filename(), flags);
}
} else {
throw Error("file '%s' has an unsupported type", from.path());
}
setWriteTime(to, statOfFrom);
if (flags.deleteAfter) {
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 copyFile(const Path & oldPath, const Path & newPath, CopyFileFlags flags)
{
return copy(fs::directory_entry(fs::path(oldPath)), fs::path(newPath), flags);
}
void renameFile(const Path & oldName, const Path & newName)
{
fs::rename(oldName, newName);
}
void moveFile(const Path & oldName, const Path & newName)
{
try {
renameFile(oldName, newName);
} catch (fs::filesystem_error & e) {
auto oldPath = fs::path(oldName);
auto newPath = fs::path(newName);
// For the move to be as atomic as possible, copy to a temporary
// directory
fs::path temp = createTempDir(newPath.parent_path(), "rename-tmp");
Finally removeTemp = [&]() { fs::remove(temp); };
auto tempCopyTarget = temp / "copy-target";
if (e.code().value() == EXDEV) {
fs::remove(newPath);
warn("Can’t rename %s as %s, copying instead", oldName, newName);
copy(fs::directory_entry(oldPath), tempCopyTarget, { .deleteAfter = true });
renameFile(tempCopyTarget, newPath);
}
}
}
}

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src/libutil/file-system.hh Normal file
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#pragma once
/**
* @file
*
* Utiltities for working with the file sytem and file paths.
*/
#include "types.hh"
#include "util.hh"
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <boost/lexical_cast.hpp>
#include <functional>
#include <optional>
#ifndef HAVE_STRUCT_DIRENT_D_TYPE
#define DT_UNKNOWN 0
#define DT_REG 1
#define DT_LNK 2
#define DT_DIR 3
#endif
namespace nix {
struct Sink;
struct Source;
/**
* @return An absolutized path, resolving paths relative to the
* specified directory, or the current directory otherwise. The path
* is also canonicalised.
*/
Path absPath(Path path,
std::optional<PathView> dir = {},
bool resolveSymlinks = false);
/**
* Canonicalise a path by removing all `.` or `..` components and
* double or trailing slashes. Optionally resolves all symlink
* components such that each component of the resulting path is *not*
* a symbolic link.
*/
Path canonPath(PathView path, bool resolveSymlinks = false);
/**
* Change the permissions of a path
* Not called `chmod` as it shadows and could be confused with
* `int chmod(char *, mode_t)`, which does not handle errors
*/
void chmodPath(const Path & path, mode_t mode);
/**
* @return The directory part of the given canonical path, i.e.,
* everything before the final `/`. If the path is the root or an
* immediate child thereof (e.g., `/foo`), this means `/`
* is returned.
*/
Path dirOf(const PathView path);
/**
* @return the base name of the given canonical path, i.e., everything
* following the final `/` (trailing slashes are removed).
*/
std::string_view baseNameOf(std::string_view path);
/**
* Perform tilde expansion on a path.
*/
std::string expandTilde(std::string_view path);
/**
* Check whether 'path' is a descendant of 'dir'. Both paths must be
* canonicalized.
*/
bool isInDir(std::string_view path, std::string_view dir);
/**
* Check whether 'path' is equal to 'dir' or a descendant of
* 'dir'. Both paths must be canonicalized.
*/
bool isDirOrInDir(std::string_view path, std::string_view dir);
/**
* Get status of `path`.
*/
struct stat stat(const Path & path);
struct stat lstat(const Path & path);
/**
* `lstat` the given path if it exists.
* @return std::nullopt if the path doesn't exist, or an optional containing the result of `lstat` otherwise
*/
std::optional<struct stat> maybeLstat(const Path & path);
/**
* @return true iff the given path exists.
*/
bool pathExists(const Path & path);
/**
* A version of pathExists that returns false on a permission error.
* Useful for inferring default paths across directories that might not
* be readable.
* @return true iff the given path can be accessed and exists
*/
bool pathAccessible(const Path & path);
/**
* Read the contents (target) of a symbolic link. The result is not
* in any way canonicalised.
*/
Path readLink(const Path & path);
bool isLink(const Path & path);
/**
* Read the contents of a directory. The entries `.` and `..` are
* removed.
*/
struct DirEntry
{
std::string name;
ino_t ino;
/**
* one of DT_*
*/
unsigned char type;
DirEntry(std::string name, ino_t ino, unsigned char type)
: name(std::move(name)), ino(ino), type(type) { }
};
typedef std::vector<DirEntry> DirEntries;
DirEntries readDirectory(const Path & path);
unsigned char getFileType(const Path & path);
/**
* Read the contents of a file into a string.
*/
std::string readFile(int fd);
std::string readFile(const Path & path);
void readFile(const Path & path, Sink & sink);
/**
* Write a string to a file.
*/
void writeFile(const Path & path, std::string_view s, mode_t mode = 0666, bool sync = false);
void writeFile(const Path & path, Source & source, mode_t mode = 0666, bool sync = false);
/**
* Flush a file's parent directory to disk
*/
void syncParent(const Path & path);
/**
* Delete a path; i.e., in the case of a directory, it is deleted
* recursively. It's not an error if the path does not exist. The
* second variant returns the number of bytes and blocks freed.
*/
void deletePath(const Path & path);
void deletePath(const Path & path, uint64_t & bytesFreed);
/**
* Create a directory and all its parents, if necessary. Returns the
* list of created directories, in order of creation.
*/
Paths createDirs(const Path & path);
inline Paths createDirs(PathView path)
{
return createDirs(Path(path));
}
/**
* Create a symlink.
*/
void createSymlink(const Path & target, const Path & link);
/**
* Atomically create or replace a symlink.
*/
void replaceSymlink(const Path & target, const Path & link);
void renameFile(const Path & src, const Path & dst);
/**
* Similar to 'renameFile', but fallback to a copy+remove if `src` and `dst`
* are on a different filesystem.
*
* Beware that this might not be atomic because of the copy that happens behind
* the scenes
*/
void moveFile(const Path & src, const Path & dst);
struct CopyFileFlags
{
/**
* Delete the file after copying.
*/
bool deleteAfter = false;
/**
* Follow symlinks and copy the eventual target.
*/
bool followSymlinks = false;
};
/**
* Recursively copy the content of `oldPath` to `newPath`. If `andDelete` is
* `true`, then also remove `oldPath` (making this equivalent to `moveFile`, but
* with the guaranty that the destination will be “fresh”, with no stale inode
* or file descriptor pointing to it).
*/
void copyFile(const Path & oldPath, const Path & newPath, CopyFileFlags flags);
/**
* Automatic cleanup of resources.
*/
class AutoDelete
{
Path path;
bool del;
bool recursive;
public:
AutoDelete();
AutoDelete(const Path & p, bool recursive = true);
~AutoDelete();
void cancel();
void reset(const Path & p, bool recursive = true);
operator Path() const { return path; }
operator PathView() const { return path; }
};
struct DIRDeleter
{
void operator()(DIR * dir) const {
closedir(dir);
}
};
typedef std::unique_ptr<DIR, DIRDeleter> AutoCloseDir;
/**
* Create a temporary directory.
*/
Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);
/**
* Create a temporary file, returning a file handle and its path.
*/
std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix");
/**
* Used in various places.
*/
typedef std::function<bool(const Path & path)> PathFilter;
extern PathFilter defaultPathFilter;
}

176
src/libutil/filesystem.cc
View file

@ -1,176 +0,0 @@
#include <sys/time.h>
#include <filesystem>
#include <atomic>
#include "environment-variables.hh"
#include "finally.hh"
#include "util.hh"
#include "signals.hh"
#include "types.hh"
namespace fs = std::filesystem;
namespace nix {
static Path tempName(Path tmpRoot, const Path & prefix, bool includePid,
std::atomic<unsigned int> & counter)
{
tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true);
if (includePid)
return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++);
else
return fmt("%1%/%2%-%3%", tmpRoot, prefix, counter++);
}
Path createTempDir(const Path & tmpRoot, const Path & prefix,
bool includePid, bool useGlobalCounter, mode_t mode)
{
static std::atomic<unsigned int> globalCounter = 0;
std::atomic<unsigned int> localCounter = 0;
auto & counter(useGlobalCounter ? globalCounter : localCounter);
while (1) {
checkInterrupt();
Path tmpDir = tempName(tmpRoot, prefix, includePid, counter);
if (mkdir(tmpDir.c_str(), mode) == 0) {
#if __FreeBSD__
/* Explicitly set the group of the directory. This is to
work around around problems caused by BSD's group
ownership semantics (directories inherit the group of
the parent). For instance, the group of /tmp on
FreeBSD is "wheel", so all directories created in /tmp
will be owned by "wheel"; but if the user is not in
"wheel", then "tar" will fail to unpack archives that
have the setgid bit set on directories. */
if (chown(tmpDir.c_str(), (uid_t) -1, getegid()) != 0)
throw SysError("setting group of directory '%1%'", tmpDir);
#endif
return tmpDir;
}
if (errno != EEXIST)
throw SysError("creating directory '%1%'", tmpDir);
}
}
std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix)
{
Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX");
// Strictly speaking, this is UB, but who cares...
// FIXME: use O_TMPFILE.
AutoCloseFD fd(mkstemp((char *) tmpl.c_str()));
if (!fd)
throw SysError("creating temporary file '%s'", tmpl);
closeOnExec(fd.get());
return {std::move(fd), tmpl};
}
void createSymlink(const Path & target, const Path & link)
{
if (symlink(target.c_str(), link.c_str()))
throw SysError("creating symlink from '%1%' to '%2%'", link, target);
}
void replaceSymlink(const Path & target, const Path & link)
{
for (unsigned int n = 0; true; n++) {
Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link)));
try {
createSymlink(target, tmp);
} catch (SysError & e) {
if (e.errNo == EEXIST) continue;
throw;
}
renameFile(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,
};
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, CopyFileFlags flags)
{
// 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 (flags.deleteAfter && 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)) {
auto opts = fs::copy_options::overwrite_existing;
if (!flags.followSymlinks) {
opts |= fs::copy_options::copy_symlinks;
}
fs::copy(from.path(), to, opts);
} else if (fs::is_directory(fromStatus)) {
fs::create_directory(to);
for (auto & entry : fs::directory_iterator(from.path())) {
copy(entry, to / entry.path().filename(), flags);
}
} else {
throw Error("file '%s' has an unsupported type", from.path());
}
setWriteTime(to, statOfFrom);
if (flags.deleteAfter) {
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 copyFile(const Path & oldPath, const Path & newPath, CopyFileFlags flags)
{
return copy(fs::directory_entry(fs::path(oldPath)), fs::path(newPath), flags);
}
void renameFile(const Path & oldName, const Path & newName)
{
fs::rename(oldName, newName);
}
void moveFile(const Path & oldName, const Path & newName)
{
try {
renameFile(oldName, newName);
} catch (fs::filesystem_error & e) {
auto oldPath = fs::path(oldName);
auto newPath = fs::path(newName);
// For the move to be as atomic as possible, copy to a temporary
// directory
fs::path temp = createTempDir(newPath.parent_path(), "rename-tmp");
Finally removeTemp = [&]() { fs::remove(temp); };
auto tempCopyTarget = temp / "copy-target";
if (e.code().value() == EXDEV) {
fs::remove(newPath);
warn("Can’t rename %s as %s, copying instead", oldName, newName);
copy(fs::directory_entry(oldPath), tempCopyTarget, { .deleteAfter = true });
renameFile(tempCopyTarget, newPath);
}
}
}
}

1
src/libutil/hash.hh
View file

@ -3,6 +3,7 @@
#include "types.hh"
#include "serialise.hh"
#include "file-system.hh"
namespace nix {

6
src/libutil/input-accessor.hh
View file

@ -1,8 +1,10 @@
#pragma once
///@file
#include "types.hh"
#include "archive.hh"
#include <map>
#include <optional>
#include <string>
namespace nix {

3
src/libutil/meson.build
View file

@ -13,7 +13,7 @@ libutil_sources = files(
'escape-string.cc',
'exit.cc',
'experimental-features.cc',
'filesystem.cc',
'file-system.cc',
'git.cc',
'hash.cc',
'hilite.cc',
@ -62,6 +62,7 @@ libutil_headers = files(
'exit.hh',
'experimental-features.hh',
'experimental-features-json.hh',
'file-system.hh',
'finally.hh',
'fmt.hh',
'git.hh',

1
src/libutil/namespaces.cc
View file

@ -1,5 +1,6 @@
#if __linux__
#include "file-system.hh"
#include "namespaces.hh"
#include "util.hh"
#include "finally.hh"

2
src/libutil/source-path.hh
View file

@ -6,7 +6,9 @@
*/
#include "ref.hh"
#include "archive.hh"
#include "canon-path.hh"
#include "file-system.hh"
#include "repair-flag.hh"
#include "input-accessor.hh"

1
src/libutil/tarfile.cc
View file

@ -1,6 +1,7 @@
#include <archive.h>
#include <archive_entry.h>
#include "file-system.hh"
#include "serialise.hh"
#include "tarfile.hh"

501
src/libutil/util.cc
View file

@ -5,6 +5,7 @@
#include "cgroup.hh"
#include "signals.hh"
#include "environment-variables.hh"
#include "file-system.hh"
#include <array>
#include <cctype>
@ -50,352 +51,6 @@
namespace nix {
Path absPath(Path path, std::optional<PathView> dir, bool resolveSymlinks)
{
if (path.empty() || path[0] != '/') {
if (!dir) {
#ifdef __GNU__
/* GNU (aka. GNU/Hurd) doesn't have any limitation on path
lengths and doesn't define `PATH_MAX'. */
char *buf = getcwd(NULL, 0);
if (buf == NULL)
#else
char buf[PATH_MAX];
if (!getcwd(buf, sizeof(buf)))
#endif
throw SysError("cannot get cwd");
path = concatStrings(buf, "/", path);
#ifdef __GNU__
free(buf);
#endif
} else
path = concatStrings(*dir, "/", path);
}
return canonPath(path, resolveSymlinks);
}
Path canonPath(PathView path, bool resolveSymlinks)
{
assert(path != "");
std::string s;
s.reserve(256);
if (path[0] != '/')
throw Error("not an absolute path: '%1%'", path);
std::string temp;
/* Count the number of times we follow a symlink and stop at some
arbitrary (but high) limit to prevent infinite loops. */
unsigned int followCount = 0, maxFollow = 1024;
while (1) {
/* Skip slashes. */
while (!path.empty() && path[0] == '/') path.remove_prefix(1);
if (path.empty()) break;
/* Ignore `.'. */
if (path == "." || path.substr(0, 2) == "./")
path.remove_prefix(1);
/* If `..', delete the last component. */
else if (path == ".." || path.substr(0, 3) == "../")
{
if (!s.empty()) s.erase(s.rfind('/'));
path.remove_prefix(2);
}
/* Normal component; copy it. */
else {
s += '/';
if (const auto slash = path.find('/'); slash == std::string::npos) {
s += path;
path = {};
} else {
s += path.substr(0, slash);
path = path.substr(slash);
}
/* If s points to a symlink, resolve it and continue from there */
if (resolveSymlinks && isLink(s)) {
if (++followCount >= maxFollow)
throw Error("infinite symlink recursion in path '%1%'", path);
temp = concatStrings(readLink(s), path);
path = temp;
if (!temp.empty() && temp[0] == '/') {
s.clear(); /* restart for symlinks pointing to absolute path */
} else {
s = dirOf(s);
if (s == "/") { // we don’t want trailing slashes here, which dirOf only produces if s = /
s.clear();
}
}
}
}
}
return s.empty() ? "/" : std::move(s);
}
void chmodPath(const Path & path, mode_t mode)
{
if (chmod(path.c_str(), mode) == -1)
throw SysError("setting permissions on '%s'", path);
}
Path dirOf(const PathView path)
{
Path::size_type pos = path.rfind('/');
if (pos == std::string::npos)
return ".";
return pos == 0 ? "/" : Path(path, 0, pos);
}
std::string_view baseNameOf(std::string_view path)
{
if (path.empty())
return "";
auto last = path.size() - 1;
if (path[last] == '/' && last > 0)
last -= 1;
auto pos = path.rfind('/', last);
if (pos == std::string::npos)
pos = 0;
else
pos += 1;
return path.substr(pos, last - pos + 1);
}
std::string expandTilde(std::string_view path)
{
// TODO: expand ~user ?
auto tilde = path.substr(0, 2);
if (tilde == "~/" || tilde == "~")
return getHome() + std::string(path.substr(1));
else
return std::string(path);
}
bool isInDir(std::string_view path, std::string_view dir)
{
return path.substr(0, 1) == "/"
&& path.substr(0, dir.size()) == dir
&& path.size() >= dir.size() + 2
&& path[dir.size()] == '/';
}
bool isDirOrInDir(std::string_view path, std::string_view dir)
{
return path == dir || isInDir(path, dir);
}
struct stat stat(const Path & path)
{
struct stat st;
if (stat(path.c_str(), &st))
throw SysError("getting status of '%1%'", path);
return st;
}
struct stat lstat(const Path & path)
{
struct stat st;
if (lstat(path.c_str(), &st))
throw SysError("getting status of '%1%'", path);
return st;
}
std::optional<struct stat> maybeLstat(const Path & path)
{
std::optional<struct stat> st{std::in_place};
if (lstat(path.c_str(), &*st))
{
if (errno == ENOENT || errno == ENOTDIR)
st.reset();
else
throw SysError("getting status of '%s'", path);
}
return st;
}
bool pathExists(const Path & path)
{
return maybeLstat(path).has_value();
}
bool pathAccessible(const Path & path)
{
try {
return pathExists(path);
} catch (SysError & e) {
// swallow EPERM
if (e.errNo == EPERM) return false;
throw;
}
}
Path readLink(const Path & path)
{
checkInterrupt();
std::vector<char> buf;
for (ssize_t bufSize = PATH_MAX/4; true; bufSize += bufSize/2) {
buf.resize(bufSize);
ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize);
if (rlSize == -1)
if (errno == EINVAL)
throw Error("'%1%' is not a symlink", path);
else
throw SysError("reading symbolic link '%1%'", path);
else if (rlSize < bufSize)
return std::string(buf.data(), rlSize);
}
}
bool isLink(const Path & path)
{
struct stat st = lstat(path);
return S_ISLNK(st.st_mode);
}
DirEntries readDirectory(DIR *dir, const Path & path)
{
DirEntries entries;
entries.reserve(64);
struct dirent * dirent;
while (errno = 0, dirent = readdir(dir)) { /* sic */
checkInterrupt();
std::string name = dirent->d_name;
if (name == "." || name == "..") continue;
entries.emplace_back(name, dirent->d_ino,
#ifdef HAVE_STRUCT_DIRENT_D_TYPE
dirent->d_type
#else
DT_UNKNOWN
#endif
);
}
if (errno) throw SysError("reading directory '%1%'", path);
return entries;
}
DirEntries readDirectory(const Path & path)
{
AutoCloseDir dir(opendir(path.c_str()));
if (!dir) throw SysError("opening directory '%1%'", path);
return readDirectory(dir.get(), path);
}
unsigned char getFileType(const Path & path)
{
struct stat st = lstat(path);
if (S_ISDIR(st.st_mode)) return DT_DIR;
if (S_ISLNK(st.st_mode)) return DT_LNK;
if (S_ISREG(st.st_mode)) return DT_REG;
return DT_UNKNOWN;
}
std::string readFile(int fd)
{
struct stat st;
if (fstat(fd, &st) == -1)
throw SysError("statting file");
return drainFD(fd, true, st.st_size);
}
std::string readFile(const Path & path)
{
AutoCloseFD fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)};
if (!fd)
throw SysError("opening file '%1%'", path);
return readFile(fd.get());
}
void readFile(const Path & path, Sink & sink)
{
AutoCloseFD fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)};
if (!fd)
throw SysError("opening file '%s'", path);
drainFD(fd.get(), sink);
}
void writeFile(const Path & path, std::string_view s, mode_t mode, bool sync)
{
AutoCloseFD fd{open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)};
if (!fd)
throw SysError("opening file '%1%'", path);
try {
writeFull(fd.get(), s);
} catch (Error & e) {
e.addTrace({}, "writing file '%1%'", path);
throw;
}
if (sync)
fd.fsync();
// Explicitly close to make sure exceptions are propagated.
fd.close();
if (sync)
syncParent(path);
}
void writeFile(const Path & path, Source & source, mode_t mode, bool sync)
{
AutoCloseFD fd{open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)};
if (!fd)
throw SysError("opening file '%1%'", path);
std::vector<char> buf(64 * 1024);
try {
while (true) {
try {
auto n = source.read(buf.data(), buf.size());
writeFull(fd.get(), {buf.data(), n});
} catch (EndOfFile &) { break; }
}
} catch (Error & e) {
e.addTrace({}, "writing file '%1%'", path);
throw;
}
if (sync)
fd.fsync();
// Explicitly close to make sure exceptions are propagated.
fd.close();
if (sync)
syncParent(path);
}
void syncParent(const Path & path)
{
AutoCloseFD fd{open(dirOf(path).c_str(), O_RDONLY, 0)};
if (!fd)
throw SysError("opening file '%1%'", path);
fd.fsync();
}
std::string readLine(int fd)
{
@ -425,98 +80,6 @@ void writeLine(int fd, std::string s)
}
static void _deletePath(int parentfd, const Path & path, uint64_t & bytesFreed)
{
checkInterrupt();
std::string name(baseNameOf(path));
struct stat st;
if (fstatat(parentfd, name.c_str(), &st, AT_SYMLINK_NOFOLLOW) == -1) {
if (errno == ENOENT) return;
throw SysError("getting status of '%1%'", path);
}
if (!S_ISDIR(st.st_mode)) {
/* We are about to delete a file. Will it likely free space? */
switch (st.st_nlink) {
/* Yes: last link. */
case 1:
bytesFreed += st.st_size;
break;
/* Maybe: yes, if 'auto-optimise-store' or manual optimisation
was performed. Instead of checking for real let's assume
it's an optimised file and space will be freed.
In worst case we will double count on freed space for files
with exactly two hardlinks for unoptimised packages.
*/
case 2:
bytesFreed += st.st_size;
break;
/* No: 3+ links. */
default:
break;
}
}
if (S_ISDIR(st.st_mode)) {
/* Make the directory accessible. */
const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR;
if ((st.st_mode & PERM_MASK) != PERM_MASK) {
if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1)
throw SysError("chmod '%1%'", path);
}
int fd = openat(parentfd, path.c_str(), O_RDONLY);
if (fd == -1)
throw SysError("opening directory '%1%'", path);
AutoCloseDir dir(fdopendir(fd));
if (!dir)
throw SysError("opening directory '%1%'", path);
for (auto & i : readDirectory(dir.get(), path))
_deletePath(dirfd(dir.get()), path + "/" + i.name, bytesFreed);
}
int flags = S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0;
if (unlinkat(parentfd, name.c_str(), flags) == -1) {
if (errno == ENOENT) return;
throw SysError("cannot unlink '%1%'", path);
}
}
static void _deletePath(const Path & path, uint64_t & bytesFreed)
{
Path dir = dirOf(path);
if (dir == "")
dir = "/";
AutoCloseFD dirfd{open(dir.c_str(), O_RDONLY)};
if (!dirfd) {
if (errno == ENOENT) return;
throw SysError("opening directory '%1%'", path);
}
_deletePath(dirfd.get(), path, bytesFreed);
}
void deletePath(const Path & path)
{
uint64_t dummy;
deletePath(path, dummy);
}
void deletePath(const Path & path, uint64_t & bytesFreed)
{
//Activity act(*logger, lvlDebug, "recursively deleting path '%1%'", path);
bytesFreed = 0;
_deletePath(path, bytesFreed);
}
std::string getUserName()
{
auto pw = getpwuid(geteuid());
@ -632,28 +195,6 @@ std::optional<Path> getSelfExe()
}
Paths createDirs(const Path & path)
{
Paths created;
if (path == "/") return created;
struct stat st;
if (lstat(path.c_str(), &st) == -1) {
created = createDirs(dirOf(path));
if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST)
throw SysError("creating directory '%1%'", path);
st = lstat(path);
created.push_back(path);
}
if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1)
throw SysError("statting symlink '%1%'", path);
if (!S_ISDIR(st.st_mode)) throw Error("'%1%' is not a directory", path);
return created;
}
void readFull(int fd, char * buf, size_t count)
{
@ -762,46 +303,6 @@ unsigned int getMaxCPU()
//////////////////////////////////////////////////////////////////////
AutoDelete::AutoDelete() : del{false} {}
AutoDelete::AutoDelete(const std::string & p, bool recursive) : path(p)
{
del = true;
this->recursive = recursive;
}
AutoDelete::~AutoDelete()
{
try {
if (del) {
if (recursive)
deletePath(path);
else {
if (remove(path.c_str()) == -1)
throw SysError("cannot unlink '%1%'", path);
}
}
} catch (...) {
ignoreException();
}
}
void AutoDelete::cancel()
{
del = false;
}
void AutoDelete::reset(const Path & p, bool recursive) {
path = p;
this->recursive = recursive;
del = true;
}
//////////////////////////////////////////////////////////////////////
AutoCloseFD::AutoCloseFD() : fd{-1} {}

239
src/libutil/util.hh
View file

@ -39,135 +39,6 @@ struct Source;
extern const std::string nativeSystem;
/**
* @return An absolutized path, resolving paths relative to the
* specified directory, or the current directory otherwise. The path
* is also canonicalised.
*/
Path absPath(Path path,
std::optional<PathView> dir = {},
bool resolveSymlinks = false);
/**
* Canonicalise a path by removing all `.` or `..` components and
* double or trailing slashes. Optionally resolves all symlink
* components such that each component of the resulting path is *not*
* a symbolic link.
*/
Path canonPath(PathView path, bool resolveSymlinks = false);
/**
* Change the permissions of a path
* Not called `chmod` as it shadows and could be confused with
* `int chmod(char *, mode_t)`, which does not handle errors
*/
void chmodPath(const Path & path, mode_t mode);
/**
* @return The directory part of the given canonical path, i.e.,
* everything before the final `/`. If the path is the root or an
* immediate child thereof (e.g., `/foo`), this means `/`
* is returned.
*/
Path dirOf(const PathView path);
/**
* @return the base name of the given canonical path, i.e., everything
* following the final `/` (trailing slashes are removed).
*/
std::string_view baseNameOf(std::string_view path);
/**
* Perform tilde expansion on a path.
*/
std::string expandTilde(std::string_view path);
/**
* Check whether 'path' is a descendant of 'dir'. Both paths must be
* canonicalized.
*/
bool isInDir(std::string_view path, std::string_view dir);
/**
* Check whether 'path' is equal to 'dir' or a descendant of
* 'dir'. Both paths must be canonicalized.
*/
bool isDirOrInDir(std::string_view path, std::string_view dir);
/**
* Get status of `path`.
*/
struct stat stat(const Path & path);
struct stat lstat(const Path & path);
/**
* `lstat` the given path if it exists.
* @return std::nullopt if the path doesn't exist, or an optional containing the result of `lstat` otherwise
*/
std::optional<struct stat> maybeLstat(const Path & path);
/**
* @return true iff the given path exists.
*/
bool pathExists(const Path & path);
/**
* A version of pathExists that returns false on a permission error.
* Useful for inferring default paths across directories that might not
* be readable.
* @return true iff the given path can be accessed and exists
*/
bool pathAccessible(const Path & path);
/**
* Read the contents (target) of a symbolic link. The result is not
* in any way canonicalised.
*/
Path readLink(const Path & path);
bool isLink(const Path & path);
/**
* Read the contents of a directory. The entries `.` and `..` are
* removed.
*/
struct DirEntry
{
std::string name;
ino_t ino;
/**
* one of DT_*
*/
unsigned char type;
DirEntry(std::string name, ino_t ino, unsigned char type)
: name(std::move(name)), ino(ino), type(type) { }
};
typedef std::vector<DirEntry> DirEntries;
DirEntries readDirectory(const Path & path);
unsigned char getFileType(const Path & path);
/**
* Read the contents of a file into a string.
*/
std::string readFile(int fd);
std::string readFile(const Path & path);
void readFile(const Path & path, Sink & sink);
/**
* Write a string to a file.
*/
void writeFile(const Path & path, std::string_view s, mode_t mode = 0666, bool sync = false);
void writeFile(const Path & path, Source & source, mode_t mode = 0666, bool sync = false);
/**
* Flush a file's parent directory to disk
*/
void syncParent(const Path & path);
/**
* Read a line from a file descriptor.
*/
@ -178,14 +49,6 @@ std::string readLine(int fd);
*/
void writeLine(int fd, std::string s);
/**
* Delete a path; i.e., in the case of a directory, it is deleted
* recursively. It's not an error if the path does not exist. The
* second variant returns the number of bytes and blocks freed.
*/
void deletePath(const Path & path);
void deletePath(const Path & path, uint64_t & bytesFreed);
std::string getUserName();
@ -238,57 +101,6 @@ Path getStateDir();
*/
Path createNixStateDir();
/**
* Create a directory and all its parents, if necessary. Returns the
* list of created directories, in order of creation.
*/
Paths createDirs(const Path & path);
inline Paths createDirs(PathView path)
{
return createDirs(Path(path));
}
/**
* Create a symlink.
*/
void createSymlink(const Path & target, const Path & link);
/**
* Atomically create or replace a symlink.
*/
void replaceSymlink(const Path & target, const Path & link);
void renameFile(const Path & src, const Path & dst);
/**
* Similar to 'renameFile', but fallback to a copy+remove if `src` and `dst`
* are on a different filesystem.
*
* Beware that this might not be atomic because of the copy that happens behind
* the scenes
*/
void moveFile(const Path & src, const Path & dst);
struct CopyFileFlags
{
/**
* Delete the file after copying.
*/
bool deleteAfter = false;
/**
* Follow symlinks and copy the eventual target.
*/
bool followSymlinks = false;
};
/**
* Recursively copy the content of `oldPath` to `newPath`. If `andDelete` is
* `true`, then also remove `oldPath` (making this equivalent to `moveFile`, but
* with the guaranty that the destination will be “fresh”, with no stale inode
* or file descriptor pointing to it).
*/
void copyFile(const Path & oldPath, const Path & newPath, CopyFileFlags flags);
/**
* Wrappers arount read()/write() that read/write exactly the
@ -313,27 +125,6 @@ void drainFD(int fd, Sink & sink, bool block = true);
*/
unsigned int getMaxCPU();
/**
* Automatic cleanup of resources.
*/
class AutoDelete
{
Path path;
bool del;
bool recursive;
public:
AutoDelete();
AutoDelete(const Path & p, bool recursive = true);
~AutoDelete();
void cancel();
void reset(const Path & p, bool recursive = true);
operator Path() const { return path; }
operator PathView() const { return path; }
};
class AutoCloseFD
{
int fd;
@ -353,19 +144,6 @@ public:
void reset() { *this = {}; }
};
/**
* Create a temporary directory.
*/
Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);
/**
* Create a temporary file, returning a file handle and its path.
*/
std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix");
class Pipe
{
public:
@ -375,16 +153,6 @@ public:
};
struct DIRDeleter
{
void operator()(DIR * dir) const {
closedir(dir);
}
};
typedef std::unique_ptr<DIR, DIRDeleter> AutoCloseDir;
class Pid
{
pid_t pid = -1;
@ -823,13 +591,6 @@ struct MaintainCount
};
/**
* Used in various places.
*/
typedef std::function<bool(const Path & path)> PathFilter;
extern PathFilter defaultPathFilter;
/**
* Common initialisation performed in child processes.
*/

1
src/nix-collect-garbage/nix-collect-garbage.cc
View file

@ -1,3 +1,4 @@
#include "file-system.hh"
#include "store-api.hh"
#include "store-cast.hh"
#include "gc-store.hh"

1
tests/unit/libstore/machines.cc
View file

@ -1,3 +1,4 @@
#include "file-system.hh"
#include "machines.hh"
#include "globals.hh"
#include "tests/test-data.hh"

2
tests/unit/libutil-support/tests/characterization.hh
View file

@ -2,6 +2,8 @@
///@file
#include "environment-variables.hh"
#include "file-system.hh"
#include <gtest/gtest.h>
#include <filesystem>

1
tests/unit/libutil/tests.cc
View file

@ -1,3 +1,4 @@
#include "file-system.hh"
#include "util.hh"
#include "types.hh"
#include "terminal.hh"