682 lines
18 KiB
C++
682 lines
18 KiB
C++
#pragma once
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#include "types.hh"
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#include "error.hh"
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#include "logging.hh"
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#include "ansicolor.hh"
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <dirent.h>
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#include <unistd.h>
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#include <signal.h>
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#include <boost/lexical_cast.hpp>
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#include <atomic>
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#include <functional>
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#include <map>
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#include <sstream>
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#include <optional>
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#ifndef HAVE_STRUCT_DIRENT_D_TYPE
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#define DT_UNKNOWN 0
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#define DT_REG 1
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#define DT_LNK 2
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#define DT_DIR 3
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#endif
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namespace nix {
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struct Sink;
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struct Source;
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/* The system for which Nix is compiled. */
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extern const std::string nativeSystem;
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/* Return an environment variable. */
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std::optional<std::string> getEnv(const std::string & key);
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/* Get the entire environment. */
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std::map<std::string, std::string> getEnv();
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/* Clear the environment. */
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void clearEnv();
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/* Return an absolutized path, resolving paths relative to the
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specified directory, or the current directory otherwise. The path
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is also canonicalised. */
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Path absPath(Path path,
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std::optional<PathView> dir = {},
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bool resolveSymlinks = false);
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/* Canonicalise a path by removing all `.' or `..' components and
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double or trailing slashes. Optionally resolves all symlink
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components such that each component of the resulting path is *not*
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a symbolic link. */
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Path canonPath(PathView path, bool resolveSymlinks = false);
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/* Return the directory part of the given canonical path, i.e.,
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everything before the final `/'. If the path is the root or an
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immediate child thereof (e.g., `/foo'), this means `/'
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is returned.*/
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Path dirOf(const PathView path);
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/* Return the base name of the given canonical path, i.e., everything
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following the final `/' (trailing slashes are removed). */
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std::string_view baseNameOf(std::string_view path);
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/* Check whether 'path' is a descendant of 'dir'. Both paths must be
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canonicalized. */
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bool isInDir(std::string_view path, std::string_view dir);
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/* Check whether 'path' is equal to 'dir' or a descendant of
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'dir'. Both paths must be canonicalized. */
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bool isDirOrInDir(std::string_view path, std::string_view dir);
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/* Get status of `path'. */
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struct stat lstat(const Path & path);
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/* Return true iff the given path exists. */
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bool pathExists(const Path & path);
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/* Read the contents (target) of a symbolic link. The result is not
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in any way canonicalised. */
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Path readLink(const Path & path);
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bool isLink(const Path & path);
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/* Read the contents of a directory. The entries `.' and `..' are
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removed. */
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struct DirEntry
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{
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std::string name;
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ino_t ino;
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unsigned char type; // one of DT_*
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DirEntry(std::string name, ino_t ino, unsigned char type)
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: name(std::move(name)), ino(ino), type(type) { }
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};
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typedef std::vector<DirEntry> DirEntries;
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DirEntries readDirectory(const Path & path);
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unsigned char getFileType(const Path & path);
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/* Read the contents of a file into a string. */
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std::string readFile(int fd);
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std::string readFile(const Path & path);
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void readFile(const Path & path, Sink & sink);
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/* Write a string to a file. */
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void writeFile(const Path & path, std::string_view s, mode_t mode = 0666);
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void writeFile(const Path & path, Source & source, mode_t mode = 0666);
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/* Read a line from a file descriptor. */
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std::string readLine(int fd);
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/* Write a line to a file descriptor. */
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void writeLine(int fd, std::string s);
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/* Delete a path; i.e., in the case of a directory, it is deleted
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recursively. It's not an error if the path does not exist. The
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second variant returns the number of bytes and blocks freed. */
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void deletePath(const Path & path);
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void deletePath(const Path & path, uint64_t & bytesFreed);
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std::string getUserName();
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/* Return $HOME or the user's home directory from /etc/passwd. */
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Path getHome();
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/* Return $XDG_CACHE_HOME or $HOME/.cache. */
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Path getCacheDir();
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/* Return $XDG_CONFIG_HOME or $HOME/.config. */
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Path getConfigDir();
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/* Return the directories to search for user configuration files */
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std::vector<Path> getConfigDirs();
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/* Return $XDG_DATA_HOME or $HOME/.local/share. */
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Path getDataDir();
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/* Create a directory and all its parents, if necessary. Returns the
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list of created directories, in order of creation. */
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Paths createDirs(const Path & path);
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inline Paths createDirs(PathView path) {
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return createDirs(Path(path));
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}
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/* Create a symlink. */
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void createSymlink(const Path & target, const Path & link,
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std::optional<time_t> mtime = {});
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/* Atomically create or replace a symlink. */
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void replaceSymlink(const Path & target, const Path & link,
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std::optional<time_t> mtime = {});
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/* Wrappers arount read()/write() that read/write exactly the
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requested number of bytes. */
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void readFull(int fd, char * buf, size_t count);
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void writeFull(int fd, std::string_view s, bool allowInterrupts = true);
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MakeError(EndOfFile, Error);
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/* Read a file descriptor until EOF occurs. */
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std::string drainFD(int fd, bool block = true, const size_t reserveSize=0);
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void drainFD(int fd, Sink & sink, bool block = true);
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/* Automatic cleanup of resources. */
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class AutoDelete
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{
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Path path;
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bool del;
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bool recursive;
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public:
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AutoDelete();
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AutoDelete(const Path & p, bool recursive = true);
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~AutoDelete();
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void cancel();
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void reset(const Path & p, bool recursive = true);
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operator Path() const { return path; }
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operator PathView() const { return path; }
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};
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class AutoCloseFD
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{
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int fd;
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public:
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AutoCloseFD();
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AutoCloseFD(int fd);
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AutoCloseFD(const AutoCloseFD & fd) = delete;
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AutoCloseFD(AutoCloseFD&& fd);
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~AutoCloseFD();
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AutoCloseFD& operator =(const AutoCloseFD & fd) = delete;
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AutoCloseFD& operator =(AutoCloseFD&& fd);
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int get() const;
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explicit operator bool() const;
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int release();
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void close();
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};
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/* Create a temporary directory. */
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Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
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bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);
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/* Create a temporary file, returning a file handle and its path. */
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std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix");
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class Pipe
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{
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public:
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AutoCloseFD readSide, writeSide;
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void create();
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void close();
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};
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struct DIRDeleter
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{
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void operator()(DIR * dir) const {
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closedir(dir);
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}
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};
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typedef std::unique_ptr<DIR, DIRDeleter> AutoCloseDir;
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class Pid
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{
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pid_t pid = -1;
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bool separatePG = false;
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int killSignal = SIGKILL;
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public:
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Pid();
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Pid(pid_t pid);
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~Pid();
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void operator =(pid_t pid);
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operator pid_t();
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int kill();
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int wait();
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void setSeparatePG(bool separatePG);
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void setKillSignal(int signal);
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pid_t release();
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};
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/* Kill all processes running under the specified uid by sending them
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a SIGKILL. */
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void killUser(uid_t uid);
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/* Fork a process that runs the given function, and return the child
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pid to the caller. */
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struct ProcessOptions
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{
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std::string errorPrefix = "";
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bool dieWithParent = true;
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bool runExitHandlers = false;
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bool allowVfork = false;
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};
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pid_t startProcess(std::function<void()> fun, const ProcessOptions & options = ProcessOptions());
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/* Run a program and return its stdout in a string (i.e., like the
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shell backtick operator). */
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std::string runProgram(Path program, bool searchPath = false,
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const Strings & args = Strings(),
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const std::optional<std::string> & input = {});
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struct RunOptions
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{
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Path program;
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bool searchPath = true;
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Strings args;
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std::optional<uid_t> uid;
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std::optional<uid_t> gid;
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std::optional<Path> chdir;
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std::optional<std::map<std::string, std::string>> environment;
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std::optional<std::string> input;
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Source * standardIn = nullptr;
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Sink * standardOut = nullptr;
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bool mergeStderrToStdout = false;
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};
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std::pair<int, std::string> runProgram(RunOptions && options);
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void runProgram2(const RunOptions & options);
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/* Change the stack size. */
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void setStackSize(size_t stackSize);
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/* Restore the original inherited Unix process context (such as signal
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masks, stack size). */
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void restoreProcessContext(bool restoreMounts = true);
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/* Save the current mount namespace. Ignored if called more than
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once. */
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void saveMountNamespace();
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/* Restore the mount namespace saved by saveMountNamespace(). Ignored
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if saveMountNamespace() was never called. */
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void restoreMountNamespace();
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/* Cause this thread to not share any FS attributes with the main
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thread, because this causes setns() in restoreMountNamespace() to
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fail. */
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void unshareFilesystem();
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class ExecError : public Error
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{
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public:
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int status;
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template<typename... Args>
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ExecError(int status, const Args & ... args)
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: Error(args...), status(status)
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{ }
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};
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/* Convert a list of strings to a null-terminated vector of char
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*'s. The result must not be accessed beyond the lifetime of the
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list of strings. */
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std::vector<char *> stringsToCharPtrs(const Strings & ss);
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/* Close all file descriptors except those listed in the given set.
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Good practice in child processes. */
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void closeMostFDs(const std::set<int> & exceptions);
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/* Set the close-on-exec flag for the given file descriptor. */
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void closeOnExec(int fd);
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/* User interruption. */
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extern std::atomic<bool> _isInterrupted;
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extern thread_local std::function<bool()> interruptCheck;
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void setInterruptThrown();
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void _interrupted();
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void inline checkInterrupt()
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{
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if (_isInterrupted || (interruptCheck && interruptCheck()))
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_interrupted();
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}
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MakeError(Interrupted, BaseError);
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MakeError(FormatError, Error);
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/* String tokenizer. */
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template<class C> C tokenizeString(std::string_view s, std::string_view separators = " \t\n\r");
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/* Concatenate the given strings with a separator between the
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elements. */
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template<class C>
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std::string concatStringsSep(const std::string_view sep, const C & ss)
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{
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size_t size = 0;
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// need a cast to string_view since this is also called with Symbols
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for (const auto & s : ss) size += sep.size() + std::string_view(s).size();
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std::string s;
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s.reserve(size);
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for (auto & i : ss) {
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if (s.size() != 0) s += sep;
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s += i;
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}
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return s;
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}
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template<class ... Parts>
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auto concatStrings(Parts && ... parts)
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-> std::enable_if_t<(... && std::is_convertible_v<Parts, std::string_view>), std::string>
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{
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std::string_view views[sizeof...(parts)] = { parts... };
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return concatStringsSep({}, views);
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}
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/* Add quotes around a collection of strings. */
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template<class C> Strings quoteStrings(const C & c)
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{
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Strings res;
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for (auto & s : c)
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res.push_back("'" + s + "'");
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return res;
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}
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/* Remove trailing whitespace from a string. FIXME: return
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std::string_view. */
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std::string chomp(std::string_view s);
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/* Remove whitespace from the start and end of a string. */
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std::string trim(std::string_view s, std::string_view whitespace = " \n\r\t");
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/* Replace all occurrences of a string inside another string. */
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std::string replaceStrings(
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std::string s,
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std::string_view from,
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std::string_view to);
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std::string rewriteStrings(std::string s, const StringMap & rewrites);
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/* Convert the exit status of a child as returned by wait() into an
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error string. */
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std::string statusToString(int status);
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bool statusOk(int status);
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/* Parse a string into an integer. */
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template<class N>
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std::optional<N> string2Int(const std::string_view s)
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{
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if (s.substr(0, 1) == "-" && !std::numeric_limits<N>::is_signed)
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return std::nullopt;
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try {
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return boost::lexical_cast<N>(s.data(), s.size());
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} catch (const boost::bad_lexical_cast &) {
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return std::nullopt;
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}
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}
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/* Like string2Int(), but support an optional suffix 'K', 'M', 'G' or
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'T' denoting a binary unit prefix. */
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template<class N>
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N string2IntWithUnitPrefix(std::string_view s)
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{
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N multiplier = 1;
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if (!s.empty()) {
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char u = std::toupper(*s.rbegin());
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if (std::isalpha(u)) {
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if (u == 'K') multiplier = 1ULL << 10;
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else if (u == 'M') multiplier = 1ULL << 20;
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else if (u == 'G') multiplier = 1ULL << 30;
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else if (u == 'T') multiplier = 1ULL << 40;
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else throw UsageError("invalid unit specifier '%1%'", u);
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s.remove_suffix(1);
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}
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}
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if (auto n = string2Int<N>(s))
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return *n * multiplier;
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throw UsageError("'%s' is not an integer", s);
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}
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/* Parse a string into a float. */
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template<class N>
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std::optional<N> string2Float(const std::string_view s)
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{
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try {
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return boost::lexical_cast<N>(s.data(), s.size());
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} catch (const boost::bad_lexical_cast &) {
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return std::nullopt;
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}
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}
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/* Return true iff `s' starts with `prefix'. */
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bool hasPrefix(std::string_view s, std::string_view prefix);
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/* Return true iff `s' ends in `suffix'. */
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bool hasSuffix(std::string_view s, std::string_view suffix);
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/* Convert a string to lower case. */
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std::string toLower(const std::string & s);
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/* Escape a string as a shell word. */
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std::string shellEscape(const std::string_view s);
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/* Exception handling in destructors: print an error message, then
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ignore the exception. */
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void ignoreException();
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/* Tree formatting. */
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constexpr char treeConn[] = "├───";
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constexpr char treeLast[] = "└───";
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constexpr char treeLine[] = "│ ";
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constexpr char treeNull[] = " ";
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/* Determine whether ANSI escape sequences are appropriate for the
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present output. */
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bool shouldANSI();
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/* Truncate a string to 'width' printable characters. If 'filterAll'
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is true, all ANSI escape sequences are filtered out. Otherwise,
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some escape sequences (such as colour setting) are copied but not
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included in the character count. Also, tabs are expanded to
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spaces. */
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std::string filterANSIEscapes(const std::string & s,
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bool filterAll = false,
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unsigned int width = std::numeric_limits<unsigned int>::max());
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/* Base64 encoding/decoding. */
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std::string base64Encode(std::string_view s);
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std::string base64Decode(std::string_view s);
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/* Remove common leading whitespace from the lines in the string
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's'. For example, if every line is indented by at least 3 spaces,
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then we remove 3 spaces from the start of every line. */
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std::string stripIndentation(std::string_view s);
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/* Get a value for the specified key from an associate container. */
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template <class T>
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std::optional<typename T::mapped_type> get(const T & map, const typename T::key_type & key)
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{
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auto i = map.find(key);
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if (i == map.end()) return {};
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return std::optional<typename T::mapped_type>(i->second);
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}
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/* Remove and return the first item from a container. */
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template <class T>
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std::optional<typename T::value_type> remove_begin(T & c)
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{
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auto i = c.begin();
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if (i == c.end()) return {};
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auto v = std::move(*i);
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c.erase(i);
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return v;
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}
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/* Remove and return the first item from a container. */
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template <class T>
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std::optional<typename T::value_type> pop(T & c)
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{
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if (c.empty()) return {};
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auto v = std::move(c.front());
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c.pop();
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return v;
|
|
}
|
|
|
|
|
|
template<typename T>
|
|
class Callback;
|
|
|
|
|
|
/* Start a thread that handles various signals. Also block those signals
|
|
on the current thread (and thus any threads created by it). */
|
|
void startSignalHandlerThread();
|
|
|
|
struct InterruptCallback
|
|
{
|
|
virtual ~InterruptCallback() { };
|
|
};
|
|
|
|
/* Register a function that gets called on SIGINT (in a non-signal
|
|
context). */
|
|
std::unique_ptr<InterruptCallback> createInterruptCallback(
|
|
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;
|
|
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. */
|
|
typedef std::function<bool(const Path & path)> PathFilter;
|
|
|
|
extern PathFilter defaultPathFilter;
|
|
|
|
/* Common initialisation performed in child processes. */
|
|
void commonChildInit(Pipe & logPipe);
|
|
|
|
/* Create a Unix domain socket. */
|
|
AutoCloseFD createUnixDomainSocket();
|
|
|
|
/* Create a Unix domain socket in listen mode. */
|
|
AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode);
|
|
|
|
/* Bind a Unix domain socket to a path. */
|
|
void bind(int fd, const std::string & path);
|
|
|
|
/* Connect to a Unix domain socket. */
|
|
void connect(int fd, const std::string & path);
|
|
|
|
|
|
// A Rust/Python-like enumerate() iterator adapter.
|
|
// Borrowed from http://reedbeta.com/blog/python-like-enumerate-in-cpp17.
|
|
template <typename T,
|
|
typename TIter = decltype(std::begin(std::declval<T>())),
|
|
typename = decltype(std::end(std::declval<T>()))>
|
|
constexpr auto enumerate(T && iterable)
|
|
{
|
|
struct iterator
|
|
{
|
|
size_t i;
|
|
TIter iter;
|
|
bool operator != (const iterator & other) const { return iter != other.iter; }
|
|
void operator ++ () { ++i; ++iter; }
|
|
auto operator * () const { return std::tie(i, *iter); }
|
|
};
|
|
|
|
struct iterable_wrapper
|
|
{
|
|
T iterable;
|
|
auto begin() { return iterator{ 0, std::begin(iterable) }; }
|
|
auto end() { return iterator{ 0, std::end(iterable) }; }
|
|
};
|
|
|
|
return iterable_wrapper{ std::forward<T>(iterable) };
|
|
}
|
|
|
|
|
|
// C++17 std::visit boilerplate
|
|
template<class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
|
|
template<class... Ts> overloaded(Ts...) -> overloaded<Ts...>;
|
|
|
|
|
|
std::string showBytes(uint64_t bytes);
|
|
|
|
|
|
}
|