types.hxx File Reference

#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <iosfwd>
#include <string>
#include <cosmos/BitMask.hxx>
#include <cosmos/dso_export.h>
#include <cosmos/utils.hxx>

Go to the source code of this file.

Classes
class	cosmos::FileType
	Convenience wrapper around FileT. More...
class	cosmos::FileMode
	Represents the mode bits portion of a ModeT. More...

Typedefs
using	cosmos::FollowSymlinks = NamedBool<struct follow_links_t, false>
	Strong boolean type to enable following of symlinks in the file system.
using	cosmos::AutoCloseFD = NamedBool<struct close_file_t, true>
	Strong boolean type for expressing the responsibility to close file descriptors.
using	cosmos::OpenFlags = BitMask<OpenFlag>
	Collection of OpenFlag used for opening files.
using	cosmos::FileModeBits = BitMask<FileModeBit>
	BitMask of FileModeBit (represents the mode bit portion of ModeT).

Enumerations
enum class	cosmos::FileNum : int {   INVALID = -1 , STDIN = STDIN_FILENO , STDOUT = STDOUT_FILENO , STDERR = STDERR_FILENO ,   AT_CWD = AT_FDCWD , MAX_FD = ~int(0) }
	Primitive file descriptor. More...
enum class	cosmos::Inode : ino_t
	A unique file number for a file on a block device. More...
enum class	cosmos::DeviceID : dev_t
	A device file identification type (consists of major:minor parts). More...
enum class	cosmos::OpenMode : int { READ_ONLY = O_RDONLY , WRITE_ONLY = O_WRONLY , READ_WRITE = O_RDWR }
	Strong enum type wrapper for the basic open() mode flag. More...
enum class	cosmos::OpenFlag : int {   APPEND = O_APPEND , ASYNC = O_ASYNC , CLOEXEC = O_CLOEXEC , CREATE = O_CREAT ,   DIRECT = O_DIRECT , DIRECTORY = O_DIRECTORY , DSYNC = O_DSYNC , EXCLUSIVE = O_EXCL ,   NOATIME = O_NOATIME , NO_CONTROLLING_TTY = O_NOCTTY , NOFOLLOW = O_NOFOLLOW , NONBLOCK = O_NONBLOCK ,   PATH = O_PATH , SYNC = O_SYNC , TMPFILE = O_TMPFILE , TRUNCATE = O_TRUNC }
	Strong enum type wrapper for file descriptor settings on top of the basic OpenMode.. More...
enum class	cosmos::ModeT : mode_t { NONE = 0 , MODE_T_TYPE_MASK = S_IFMT , MODE_T_MODE_MASK = ~static_cast<mode_t>(S_IFMT) }
	Combined file type and mode bits of a file (as found in st_mode struct stat). More...
enum class	cosmos::FileModeBit : mode_t {   SETUID = S_ISUID , SETGID = S_ISGID , STICKY = S_ISVTX , OWNER_READ = S_IRUSR ,   OWNER_WRITE = S_IWUSR , OWNER_EXEC = S_IXUSR , OWNER_ALL = S_IRWXU , GROUP_READ = S_IRGRP ,   GROUP_WRITE = S_IWGRP , GROUP_EXEC = S_IXGRP , GROUP_ALL = S_IRWXG , OTHER_READ = S_IROTH ,   OTHER_WRITE = S_IWOTH , OTHER_EXEC = S_IXOTH , OTHER_ALL = S_IRWXO }
	Bitmask values for file mode bits. More...

Functions
ModeT	cosmos::operator& (const ModeT a, const ModeT b)
	Support bit masking operations on ModeT for extracting type and mode parts.
COSMOS_API std::ostream &	operator<< (std::ostream &o, const cosmos::FileMode mode)
	Outputs a friendly version of the FileMode information onto the stream.
COSMOS_API std::ostream &	operator<< (std::ostream &o, const cosmos::FileType type)
	Outputs a symbolic type character onto the stream.
COSMOS_API std::ostream &	operator<< (std::ostream &o, const cosmos::OpenFlags flags)
	Outputs a friendly version of the OpenFlags bitmask onto the stream.

Detailed Description

Basic types used in file system APIs.

Definition in file types.hxx.

Typedef Documentation

AutoCloseFD

using cosmos::AutoCloseFD = NamedBool<struct close_file_t, true>

Strong boolean type for expressing the responsibility to close file descriptors.

Definition at line 29 of file types.hxx.

FileModeBits

using cosmos::FileModeBits = BitMask<FileModeBit>

BitMask of FileModeBit (represents the mode bit portion of ModeT).

Definition at line 144 of file types.hxx.

FollowSymlinks

using cosmos::FollowSymlinks = NamedBool<struct follow_links_t, false>

Strong boolean type to enable following of symlinks in the file system.

Definition at line 26 of file types.hxx.

OpenFlags

using cosmos::OpenFlags = BitMask<OpenFlag>

Collection of OpenFlag used for opening files.

Definition at line 96 of file types.hxx.

Enumeration Type Documentation

DeviceID

enum class cosmos::DeviceID : dev_t

strong

A device file identification type (consists of major:minor parts).

Definition at line 48 of file types.hxx.

                    : dev_t {
};

FileModeBit

enum class cosmos::FileModeBit : mode_t

strong

Bitmask values for file mode bits.

These are the lower (07777) bits of the st_mode field in struct stat.

These make up the classical UNIX user/group/other permission bits plus the three special bits for set-uid, set-gid and sticky bit.

Definition at line 125 of file types.hxx.

                       : mode_t {
        SETUID      = S_ISUID, // set user-id bit
        SETGID      = S_ISGID, // set group-id bit
        STICKY      = S_ISVTX, // only has a meaning for directory, typically set on /tmp
        OWNER_READ  = S_IRUSR,
        OWNER_WRITE = S_IWUSR,
        OWNER_EXEC  = S_IXUSR,
        OWNER_ALL   = S_IRWXU,
        GROUP_READ  = S_IRGRP,
        GROUP_WRITE = S_IWGRP,
        GROUP_EXEC  = S_IXGRP,
        GROUP_ALL   = S_IRWXG,
        OTHER_READ  = S_IROTH,
        OTHER_WRITE = S_IWOTH,
        OTHER_EXEC  = S_IXOTH,
        OTHER_ALL   = S_IRWXO
};

FileNum

enum class cosmos::FileNum : int

strong

Primitive file descriptor.

Enumerator
AT_CWD	special constant denoting the CWD in the *at family of API calls.
MAX_FD	maximum file descriptor number; useful in fs::close_range().

Definition at line 32 of file types.hxx.

                   : int {
        INVALID = -1,
        STDIN   = STDIN_FILENO,
        STDOUT  = STDOUT_FILENO,
        STDERR  = STDERR_FILENO,
        AT_CWD  = AT_FDCWD,
        MAX_FD  = ~int(0)
};

Inode

enum class cosmos::Inode : ino_t

strong

A unique file number for a file on a block device.

Definition at line 44 of file types.hxx.

                 : ino_t {
};

ModeT

enum class cosmos::ModeT : mode_t

strong

Combined file type and mode bits of a file (as found in st_mode struct stat).

In struct stat the st_mode field contains the file type value in the upper four bits and the file mode bitmask in the lower bits.

This type should be treated mostly opaque. Operate on the two parts independently by using FileType and FileMode.

Enumerator
MODE_T_TYPE_MASK	masks all type bits
MODE_T_MODE_MASK	masks all mode bits

Definition at line 106 of file types.hxx.

                 : mode_t {
        NONE      = 0,
        MODE_T_TYPE_MASK = S_IFMT, 
        MODE_T_MODE_MASK = ~static_cast<mode_t>(S_IFMT) 
};

OpenFlag

enum class cosmos::OpenFlag : int

strong

Strong enum type wrapper for file descriptor settings on top of the basic OpenMode..

Enumerator
APPEND	Writes will always happen at the end of the file.
ASYNC	Enable signal driven I/O for certain file types.
CLOEXEC	Close file descriptor during execve() system call.
CREATE	Create the file if it doesn't exist (file mode required as well).
DIRECT	Bypass Kernel side caching.
DIRECTORY	Require the path to refer to a directory.
DSYNC	Use synchronous write operation, after write() returns everything should be written to disk.
EXCLUSIVE	Use this in conjunction with CREATE to make sure the file gets newly created.
NOATIME	Don't update the access time of the file if certain preconditions are fulfilled.
NO_CONTROLLING_TTY	If the file refers to a terminal, don't make it the controlling terminal of the calling process.
NOFOLLOW	Don't follow symlinks in the final path component.
NONBLOCK	Attempt to open the file in non-blocking mode causing I/O operations not to block.
PATH	Open only the file location, not the actual file object the resulting file descriptor can mostly only be used for Navigating the file system using *at system calls.
SYNC	Similar to DSYNC, see man page.
TMPFILE	Attempt to create an unnamed temporary file, path needs to specify the directory where to create it.
TRUNCATE	If write access was requested and is allowed then an already existing file object is truncated to zero size.

Definition at line 59 of file types.hxx.

                    : int {
        APPEND             = O_APPEND,
        ASYNC              = O_ASYNC,
        CLOEXEC            = O_CLOEXEC,
        CREATE             = O_CREAT,
        DIRECT             = O_DIRECT,
        DIRECTORY          = O_DIRECTORY,
        DSYNC              = O_DSYNC,
        EXCLUSIVE          = O_EXCL,
        NOATIME            = O_NOATIME,
        NO_CONTROLLING_TTY = O_NOCTTY,
        NOFOLLOW           = O_NOFOLLOW,
        NONBLOCK           = O_NONBLOCK,
        PATH               = O_PATH,
        SYNC               = O_SYNC,
        TMPFILE            = O_TMPFILE,
        TRUNCATE           = O_TRUNC
};

OpenMode

enum class cosmos::OpenMode : int

strong

Strong enum type wrapper for the basic open() mode flag.

Definition at line 52 of file types.hxx.

                    : int {
        READ_ONLY  = O_RDONLY,
        WRITE_ONLY = O_WRONLY,
        READ_WRITE = O_RDWR
};

Function Documentation

operator&()

ModeT cosmos::operator& ( const ModeT a, const ModeT b )

inline

Support bit masking operations on ModeT for extracting type and mode parts.

Definition at line 113 of file types.hxx.

                                                     {
        auto ret = static_cast<mode_t>(a) & static_cast<mode_t>(b);
        return static_cast<ModeT>(ret);
}

operator<<() [1/3]

COSMOS_API std::ostream & operator<<	(	std::ostream &	o,
		const cosmos::FileMode	mode )

Outputs a friendly version of the FileMode information onto the stream.

Definition at line 103 of file FileStatus.cxx.

                                                                 {
        o << mode.symbolic() << " (" << cosmos::OctNum{cosmos::to_integral(mode.raw()), 4} << ")";
        return o;
}

operator<<() [2/3]

COSMOS_API std::ostream & operator<<	(	std::ostream &	o,
		const cosmos::FileType	type )

Outputs a symbolic type character onto the stream.

Definition at line 108 of file FileStatus.cxx.

                                                                 {
        o << type.symbolic();
        return o;
}

operator<<() [3/3]

COSMOS_API std::ostream & operator<<	(	std::ostream &	o,
		const cosmos::OpenFlags	flags )

Outputs a friendly version of the OpenFlags bitmask onto the stream.

Definition at line 113 of file FileStatus.cxx.

                                                                   {
        using Flag = cosmos::OpenFlag;
        bool first = true;
 
        for (const auto &pair: {
                        std::make_pair(Flag::APPEND,    "APPEND"),
                                      {Flag::ASYNC,     "ASYNC"},
                                      {Flag::CLOEXEC,   "CLOEXEC"},
                                      {Flag::CREATE,    "CREATE"},
                                      {Flag::DIRECT,    "DIRECT"},
                                      {Flag::DIRECTORY, "DIRECTORY"},
                                      {Flag::DSYNC,     "DSYNC"},
                                      {Flag::EXCLUSIVE, "EXCLUSIVE"},
                                      {Flag::NOATIME,   "NOATIME"},
                                      {Flag::NO_CONTROLLING_TTY, "NO_CONTROLLING_TTY"},
                                      {Flag::NOFOLLOW,  "NOFOLLOW"},
                                      {Flag::NONBLOCK,  "NONBLOCK"},
                                      {Flag::PATH,      "PATH"},
                                      {Flag::SYNC,      "SYNC"},
                                      {Flag::TMPFILE,   "TMPFILE"},
                                      {Flag::TRUNCATE,  "TRUNCATE"}
        }) {
                auto [flag, label] = pair;
 
                if (flags[flag]) {
                        if (first)
                                first = false;
                        else
                                o << ", ";
 
                        o << label;
                }
        }
 
        return o;
}