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Diffstat (limited to 'third_party/nix/src/libutil/util.hh')
| -rw-r--r-- | third_party/nix/src/libutil/util.hh | 476 |
1 files changed, 0 insertions, 476 deletions
diff --git a/third_party/nix/src/libutil/util.hh b/third_party/nix/src/libutil/util.hh deleted file mode 100644 index b3349c4f39..0000000000 --- a/third_party/nix/src/libutil/util.hh +++ /dev/null @@ -1,476 +0,0 @@ -#pragma once - -#include <cstdio> -#include <functional> -#include <future> -#include <limits> -#include <map> -#include <optional> -#include <sstream> - -#include <absl/strings/string_view.h> -#include <dirent.h> -#include <signal.h> -#include <sys/stat.h> -#include <sys/types.h> -#include <unistd.h> - -#include "libutil/types.hh" - -namespace nix { - -struct Sink; -struct Source; - -/* The system for which Nix is compiled. */ -extern const std::string nativeSystem; - -/* Return an environment variable. */ -std::optional<std::string> getEnv(const std::string& key); - -/* Get the entire environment. */ -std::map<std::string, std::string> getEnv(); - -/* Clear the environment. */ -void clearEnv(); - -/* 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, Path dir = ""); - -/* 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(const Path& path, bool resolveSymlinks = false); - -/* 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 an empty string - is returned. */ -Path dirOf(absl::string_view path); - -/* Return the base name of the given canonical path, i.e., everything - following the final `/'. */ -std::string baseNameOf(const Path& path); - -/* Check whether 'path' is a descendant of 'dir'. */ -bool isInDir(const Path& path, const Path& dir); - -/* Check whether 'path' is equal to 'dir' or a descendant of 'dir'. */ -bool isDirOrInDir(const Path& path, const Path& dir); - -/* Get status of `path'. */ -struct stat lstat(const Path& path); - -/* Return true iff the given path exists. */ -bool pathExists(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; - unsigned char type; // one of DT_* - DirEntry(const std::string& name, ino_t ino, unsigned char type) - : name(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(absl::string_view path, bool drain = false); -void readFile(absl::string_view path, Sink& sink); - -/* Write a string to a file. */ -void writeFile(const Path& path, const std::string& s, mode_t mode = 0666); - -void writeFile(const Path& path, Source& source, mode_t mode = 0666); - -/* Read a line from a file descriptor. */ -std::string readLine(int fd); - -/* Write a line to a file descriptor. */ -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, unsigned long long& bytesFreed); - -/* Create a temporary directory. */ -Path createTempDir(const Path& tmpRoot = "", const Path& prefix = "nix", - bool includePid = true, bool useGlobalCounter = true, - mode_t mode = 0755); - -std::string getUserName(); - -/* Return $HOME or the user's home directory from /etc/passwd. */ -Path getHome(); - -/* Return $XDG_CACHE_HOME or $HOME/.cache. */ -Path getCacheDir(); - -/* Return $XDG_CONFIG_HOME or $HOME/.config. */ -Path getConfigDir(); - -/* Return the directories to search for user configuration files */ -std::vector<Path> getConfigDirs(); - -/* Return $XDG_DATA_HOME or $HOME/.local/share. */ -Path getDataDir(); - -/* Create a directory and all its parents, if necessary. Returns the - list of created directories, in order of creation. */ -Paths createDirs(const 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); - -/* Wrappers arount read()/write() that read/write exactly the - requested number of bytes. */ -void readFull(int fd, unsigned char* buf, size_t count); -void writeFull(int fd, const unsigned char* buf, size_t count, - bool allowInterrupts = true); -void writeFull(int fd, const std::string& s, bool allowInterrupts = true); - -MakeError(EndOfFile, Error); - -/* Read a file descriptor until EOF occurs. */ -std::string drainFD(int fd, bool block = true); - -void drainFD(int fd, Sink& sink, bool block = true); - -/* Automatic cleanup of resources. */ - -class AutoDelete { - Path path; - bool del; - bool recursive; - - public: - AutoDelete(); - explicit AutoDelete(Path p, bool recursive = true); - ~AutoDelete(); - void cancel(); - void reset(const Path& p, bool recursive = true); - explicit operator Path() const { return path; } -}; - -class AutoCloseFD { - int fd; - void close(); - - public: - AutoCloseFD(); - explicit AutoCloseFD(int fd); - AutoCloseFD(const AutoCloseFD& fd) = delete; - AutoCloseFD(AutoCloseFD&& that); - ~AutoCloseFD(); - AutoCloseFD& operator=(const AutoCloseFD& fd) = delete; - AutoCloseFD& operator=(AutoCloseFD&& that); - int get() const; - explicit operator bool() const; - int release(); -}; - -class Pipe { - public: - AutoCloseFD readSide, writeSide; - void create(); -}; - -struct DIRDeleter { - void operator()(DIR* dir) const { closedir(dir); } -}; - -using AutoCloseDir = std::unique_ptr<DIR, DIRDeleter>; - -class Pid { - pid_t pid = -1; - bool separatePG = false; - int killSignal = SIGKILL; - - public: - Pid(); - explicit Pid(pid_t pid); - ~Pid(); - void operator=(pid_t pid); - explicit operator pid_t(); - int kill(); - int wait(); - - void setSeparatePG(bool separatePG); - void setKillSignal(int signal); - pid_t release(); - - friend bool operator==(const Pid& lhs, const Pid& rhs) { - return lhs.pid == rhs.pid; - } - - friend bool operator!=(const Pid& lhs, const Pid& rhs) { - return !(lhs == rhs); - } -}; - -/* Kill all processes running under the specified uid by sending them - a SIGKILL. */ -void killUser(uid_t uid); - -/* Fork a process that runs the given function, and return the child - pid to the caller. */ -struct ProcessOptions { - std::string errorPrefix = "error: "; - bool dieWithParent = true; - bool runExitHandlers = false; -}; - -pid_t startProcess(std::function<void()> fun, - const ProcessOptions& options = ProcessOptions()); - -/* Run a program and return its stdout in a string (i.e., like the - shell backtick operator). */ -std::string runProgram(const Path& program, bool searchPath = false, - const Strings& args = Strings(), - const std::optional<std::string>& input = {}); - -struct RunOptions { - std::optional<uid_t> uid; - std::optional<uid_t> gid; - std::optional<Path> chdir; - std::optional<std::map<std::string, std::string>> environment; - Path program; - bool searchPath = true; - Strings args; - std::optional<std::string> input; - Source* standardIn = nullptr; - Sink* standardOut = nullptr; - bool mergeStderrToStdout = false; - bool _killStderr = false; - - RunOptions(const Path& program, const Strings& args) - : program(program), args(args){}; - - RunOptions& killStderr(bool v) { - _killStderr = true; - return *this; - } -}; - -std::pair<int, std::string> runProgram(const RunOptions& options); - -void runProgram2(const RunOptions& options); - -class ExecError : public Error { - public: - int status; - - template <typename... Args> - explicit ExecError(int status, Args... args) - : Error(args...), status(status) {} -}; - -/* Convert a list of strings to a null-terminated vector of char - *'s. The result must not be accessed beyond the lifetime of the - list of strings. */ -std::vector<char*> stringsToCharPtrs(const Strings& ss); - -/* Close all file descriptors except those listed in the given set. - Good practice in child processes. */ -void closeMostFDs(const std::set<int>& exceptions); - -/* Set the close-on-exec flag for the given file descriptor. */ -void closeOnExec(int fd); - -/* User interruption. */ - -extern bool _isInterrupted; - -extern thread_local std::function<bool()> interruptCheck; - -void setInterruptThrown(); - -void _interrupted(); - -void inline checkInterrupt() { - if (_isInterrupted || (interruptCheck && interruptCheck())) { - _interrupted(); - } -} - -MakeError(Interrupted, BaseError); - -MakeError(FormatError, Error); - -/* Concatenate the given strings with a separator between the - elements. */ -std::string concatStringsSep(const std::string& sep, const Strings& ss); -std::string concatStringsSep(const std::string& sep, const StringSet& ss); - -/* Replace all occurrences of a string inside another string. */ -std::string replaceStrings(const std::string& s, const std::string& from, - const std::string& to); - -/* Convert the exit status of a child as returned by wait() into an - error string. */ -std::string statusToString(int status); - -bool statusOk(int status); - -/* Parse a string into a float. */ -template <class N> -bool string2Float(const std::string& s, N& n) { - std::istringstream str(s); - str >> n; - return str && str.get() == EOF; -} - -/* Convert a string to lower case. */ -std::string toLower(const std::string& s); - -/* Escape a string as a shell word. */ -std::string shellEscape(const std::string& s); - -/* Exception handling in destructors: print an error message, then - ignore the exception. */ -void ignoreException(); - -/* Some ANSI escape sequences. */ -#define ANSI_NORMAL "\e[0m" -#define ANSI_BOLD "\e[1m" -#define ANSI_FAINT "\e[2m" -#define ANSI_RED "\e[31;1m" -#define ANSI_GREEN "\e[32;1m" -#define ANSI_BLUE "\e[34;1m" - -/* Truncate a string to 'width' printable characters. If 'filterAll' - is true, all ANSI escape sequences are filtered out. Otherwise, - some escape sequences (such as colour setting) are copied but not - included in the character count. Also, tabs are expanded to - spaces. */ -std::string filterANSIEscapes( - const std::string& s, bool filterAll = false, - unsigned int width = std::numeric_limits<unsigned int>::max()); - -/* Get a value for the specified key from an associate container, or a - default value if the key doesn't exist. */ -template <class T> -std::string get(const T& map, const std::string& key, - const std::string& def = "") { - auto i = map.find(key); - return i == map.end() ? def : i->second; -} - -/* A callback is a wrapper around a lambda that accepts a valid of - type T or an exception. (We abuse std::future<T> to pass the value or - exception.) */ -template <typename T> -class Callback { - std::function<void(std::future<T>)> fun; - std::atomic_flag done = ATOMIC_FLAG_INIT; - - public: - explicit Callback(std::function<void(std::future<T>)> fun) : fun(fun) {} - - Callback(Callback&& callback) : fun(std::move(callback.fun)) { - auto prev = callback.done.test_and_set(); - if (prev) { - done.test_and_set(); - } - } - -// The unused-variable assert is disabled in this block because the -// `prev` variables are only used in debug mode (in the asserts). -#pragma clang diagnostic push -#pragma clang diagnostic ignored "-Wunused-variable" - - void operator()(T&& t) noexcept { - auto prev = done.test_and_set(); - assert(!prev); - std::promise<T> promise; - promise.set_value(std::move(t)); - fun(promise.get_future()); - } - - void rethrow( - const std::exception_ptr& exc = std::current_exception()) noexcept { - auto prev = done.test_and_set(); - assert(!prev); - std::promise<T> promise; - promise.set_exception(exc); - fun(promise.get_future()); - } - -#pragma clang diagnostic pop -}; - -/* Start a thread that handles various signals. Also block those signals - on the current thread (and thus any threads created by it). */ -void startSignalHandlerThread(); - -/* Restore default signal handling. */ -void restoreSignals(); - -struct InterruptCallback { - virtual ~InterruptCallback(){}; -}; - -/* Register a function that gets called on SIGINT (in a non-signal - context). */ -std::unique_ptr<InterruptCallback> createInterruptCallback( - const std::function<void()>& callback); - -void triggerInterrupt(); - -/* A RAII class that causes the current thread to receive SIGUSR1 when - the signal handler thread receives SIGINT. That is, this allows - SIGINT to be multiplexed to multiple threads. */ -struct ReceiveInterrupts { - pthread_t target; - std::unique_ptr<InterruptCallback> callback; - - ReceiveInterrupts() - : target(pthread_self()), callback(createInterruptCallback([&]() { - pthread_kill(target, SIGUSR1); - })) {} -}; - -/* A RAII helper that increments a counter on construction and - decrements it on destruction. */ -template <typename T> -struct MaintainCount { - T& counter; - long delta; - explicit MaintainCount(T& counter, long delta = 1) - : counter(counter), delta(delta) { - counter += delta; - } - ~MaintainCount() { counter -= delta; } -}; - -/* Return the number of rows and columns of the terminal. */ -std::pair<unsigned short, unsigned short> getWindowSize(); - -/* Used in various places. */ -using PathFilter = std::function<bool(const Path&)>; - -extern PathFilter defaultPathFilter; - -} // namespace nix |