451ebf24ce
This re-implements the binary cache database in C++, allowing it to be used by other Store backends, in particular the S3 backend.
439 lines
10 KiB
C++
439 lines
10 KiB
C++
#pragma once
|
||
|
||
#include "types.hh"
|
||
|
||
#include <sys/types.h>
|
||
#include <sys/stat.h>
|
||
#include <dirent.h>
|
||
#include <unistd.h>
|
||
#include <signal.h>
|
||
#include <functional>
|
||
#include <limits>
|
||
#include <cstdio>
|
||
|
||
#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 {
|
||
|
||
|
||
/* Return an environment variable. */
|
||
string getEnv(const string & key, const string & def = "");
|
||
|
||
/* 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(const Path & path);
|
||
|
||
/* Return the base name of the given canonical path, i.e., everything
|
||
following the final `/'. */
|
||
string baseNameOf(const Path & path);
|
||
|
||
/* Check whether a given path is a descendant of the given
|
||
directory. */
|
||
bool isInDir(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
|
||
{
|
||
string name;
|
||
ino_t ino;
|
||
unsigned char type; // one of DT_*
|
||
DirEntry(const string & name, ino_t ino, unsigned char type)
|
||
: name(name), ino(ino), type(type) { }
|
||
};
|
||
|
||
typedef vector<DirEntry> DirEntries;
|
||
|
||
DirEntries readDirectory(const Path & path);
|
||
|
||
unsigned char getFileType(const Path & path);
|
||
|
||
/* Read the contents of a file into a string. */
|
||
string readFile(int fd);
|
||
string readFile(const Path & path, bool drain = false);
|
||
|
||
/* Write a string to a file. */
|
||
void writeFile(const Path & path, const string & s);
|
||
|
||
/* Read a line from a file descriptor. */
|
||
string readLine(int fd);
|
||
|
||
/* Write a line to a file descriptor. */
|
||
void writeLine(int fd, 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);
|
||
|
||
/* Return the path to $XDG_CACHE_HOME/.cache. */
|
||
Path getCacheDir();
|
||
|
||
/* 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);
|
||
|
||
|
||
template<class T, class A>
|
||
T singleton(const A & a)
|
||
{
|
||
T t;
|
||
t.insert(a);
|
||
return t;
|
||
}
|
||
|
||
|
||
/* Messages. */
|
||
|
||
|
||
typedef enum {
|
||
ltPretty, /* nice, nested output */
|
||
ltEscapes, /* nesting indicated using escape codes (for log2xml) */
|
||
ltFlat, /* no nesting */
|
||
ltSystemd, /* use systemd severity prefixes */
|
||
} LogType;
|
||
|
||
extern LogType logType;
|
||
extern Verbosity verbosity; /* suppress msgs > this */
|
||
|
||
class Nest
|
||
{
|
||
private:
|
||
bool nest;
|
||
public:
|
||
Nest();
|
||
~Nest();
|
||
void open(Verbosity level, const FormatOrString & fs);
|
||
void close();
|
||
};
|
||
|
||
void printMsg_(Verbosity level, const FormatOrString & fs);
|
||
|
||
#define startNest(varName, level, f) \
|
||
Nest varName; \
|
||
if (level <= verbosity) { \
|
||
varName.open(level, (f)); \
|
||
}
|
||
|
||
#define printMsg(level, f) \
|
||
do { \
|
||
if (level <= nix::verbosity) { \
|
||
nix::printMsg_(level, (f)); \
|
||
} \
|
||
} while (0)
|
||
|
||
#define debug(f) printMsg(lvlDebug, f)
|
||
|
||
void warnOnce(bool & haveWarned, const FormatOrString & fs);
|
||
|
||
void writeToStderr(const string & s);
|
||
|
||
extern std::function<void(const unsigned char * buf, size_t count)> _writeToStderr;
|
||
|
||
|
||
/* 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);
|
||
void writeFull(int fd, const string & s);
|
||
|
||
MakeError(EndOfFile, Error)
|
||
|
||
|
||
/* Read a file descriptor until EOF occurs. */
|
||
string drainFD(int fd);
|
||
|
||
|
||
|
||
/* Automatic cleanup of resources. */
|
||
|
||
|
||
template <class T>
|
||
struct AutoDeleteArray
|
||
{
|
||
T * p;
|
||
AutoDeleteArray(T * p) : p(p) { }
|
||
~AutoDeleteArray()
|
||
{
|
||
delete [] p;
|
||
}
|
||
};
|
||
|
||
|
||
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; }
|
||
};
|
||
|
||
|
||
class AutoCloseFD
|
||
{
|
||
int fd;
|
||
public:
|
||
AutoCloseFD();
|
||
AutoCloseFD(int fd);
|
||
AutoCloseFD(const AutoCloseFD & fd);
|
||
~AutoCloseFD();
|
||
void operator =(int fd);
|
||
operator int() const;
|
||
void close();
|
||
bool isOpen();
|
||
int borrow();
|
||
};
|
||
|
||
|
||
class Pipe
|
||
{
|
||
public:
|
||
AutoCloseFD readSide, writeSide;
|
||
void create();
|
||
};
|
||
|
||
|
||
class AutoCloseDir
|
||
{
|
||
DIR * dir;
|
||
public:
|
||
AutoCloseDir();
|
||
AutoCloseDir(DIR * dir);
|
||
~AutoCloseDir();
|
||
void operator =(DIR * dir);
|
||
operator DIR *();
|
||
void close();
|
||
};
|
||
|
||
|
||
class Pid
|
||
{
|
||
pid_t pid;
|
||
bool separatePG;
|
||
int killSignal;
|
||
public:
|
||
Pid();
|
||
Pid(pid_t pid);
|
||
~Pid();
|
||
void operator =(pid_t pid);
|
||
operator pid_t();
|
||
void kill(bool quiet = false);
|
||
int wait(bool block);
|
||
void setSeparatePG(bool separatePG);
|
||
void setKillSignal(int signal);
|
||
};
|
||
|
||
|
||
/* 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
|
||
{
|
||
string errorPrefix;
|
||
bool dieWithParent;
|
||
bool runExitHandlers;
|
||
bool allowVfork;
|
||
ProcessOptions() : errorPrefix("error: "), dieWithParent(true), runExitHandlers(false), allowVfork(true) { };
|
||
};
|
||
|
||
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). */
|
||
string runProgram(Path program, bool searchPath = false,
|
||
const Strings & args = Strings(), const string & input = "");
|
||
|
||
MakeError(ExecError, Error)
|
||
|
||
/* 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 stdin, stdout, stderr, and those
|
||
listed in the given set. Good practice in child processes. */
|
||
void closeMostFDs(const set<int> & exceptions);
|
||
|
||
/* Set the close-on-exec flag for the given file descriptor. */
|
||
void closeOnExec(int fd);
|
||
|
||
/* Restore default handling of SIGPIPE, otherwise some programs will
|
||
randomly say "Broken pipe". */
|
||
void restoreSIGPIPE();
|
||
|
||
|
||
/* User interruption. */
|
||
|
||
extern volatile sig_atomic_t _isInterrupted;
|
||
|
||
extern thread_local bool interruptThrown;
|
||
|
||
void _interrupted();
|
||
|
||
void inline checkInterrupt()
|
||
{
|
||
if (_isInterrupted) _interrupted();
|
||
}
|
||
|
||
MakeError(Interrupted, BaseError)
|
||
|
||
|
||
/* String tokenizer. */
|
||
template<class C> C tokenizeString(const string & s, const string & separators = " \t\n\r");
|
||
|
||
|
||
/* Concatenate the given strings with a separator between the
|
||
elements. */
|
||
string concatStringsSep(const string & sep, const Strings & ss);
|
||
string concatStringsSep(const string & sep, const StringSet & ss);
|
||
|
||
|
||
/* Remove trailing whitespace from a string. */
|
||
string chomp(const string & s);
|
||
|
||
|
||
/* Remove whitespace from the start and end of a string. */
|
||
string trim(const string & s, const string & whitespace = " \n\r\t");
|
||
|
||
|
||
/* Replace all occurrences of a string inside another string. */
|
||
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. */
|
||
string statusToString(int status);
|
||
|
||
bool statusOk(int status);
|
||
|
||
|
||
/* Parse a string into an integer. */
|
||
template<class N> bool string2Int(const string & s, N & n)
|
||
{
|
||
if (string(s, 0, 1) == "-" && !std::numeric_limits<N>::is_signed)
|
||
return false;
|
||
std::istringstream str(s);
|
||
str >> n;
|
||
return str && str.get() == EOF;
|
||
}
|
||
|
||
/* Parse a string into a float. */
|
||
template<class N> bool string2Float(const string & s, N & n)
|
||
{
|
||
std::istringstream str(s);
|
||
str >> n;
|
||
return str && str.get() == EOF;
|
||
}
|
||
|
||
|
||
/* Return true iff `s' ends in `suffix'. */
|
||
bool hasSuffix(const string & s, const string & suffix);
|
||
|
||
|
||
/* Read string `s' from stream `str'. */
|
||
void expect(std::istream & str, const string & s);
|
||
|
||
MakeError(FormatError, Error)
|
||
|
||
|
||
/* Read a C-style string from stream `str'. */
|
||
string parseString(std::istream & str);
|
||
|
||
|
||
/* Utility function used to parse legacy ATerms. */
|
||
bool endOfList(std::istream & str);
|
||
|
||
|
||
/* Escape a string that contains octal-encoded escape codes such as
|
||
used in /etc/fstab and /proc/mounts (e.g. "foo\040bar" decodes to
|
||
"foo bar"). */
|
||
string decodeOctalEscaped(const 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_RED "\e[31;1m"
|
||
|
||
|
||
/* Filter out ANSI escape codes from the given string. If ‘nixOnly’ is
|
||
set, only filter escape codes generated by Nixpkgs' stdenv (used to
|
||
denote nesting etc.). */
|
||
string filterANSIEscapes(const string & s, bool nixOnly = false);
|
||
|
||
|
||
/* Base64 encoding/decoding. */
|
||
string base64Encode(const string & s);
|
||
string base64Decode(const string & s);
|
||
|
||
|
||
/* Get a value for the specified key from an associate container, or a
|
||
default value if the key doesn't exist. */
|
||
template <class T>
|
||
string get(const T & map, const string & key, const string & def = "")
|
||
{
|
||
auto i = map.find(key);
|
||
return i == map.end() ? def : i->second;
|
||
}
|
||
|
||
|
||
}
|