FileSystem: new library for Path-friendly file system routines

This commit is contained in:
Denis Krjuchkov 2013-01-20 16:19:53 +06:00
parent 6f4560184c
commit e6ed592b8a
3 changed files with 259 additions and 0 deletions

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@ -297,6 +297,7 @@ src_mpd_SOURCES = \
src/Volume.cxx src/Volume.hxx \
src/SongFilter.cxx src/SongFilter.hxx \
src/PlaylistFile.cxx src/PlaylistFile.hxx \
src/FileSystem.cxx src/FileSystem.hxx \
src/timer.c
#

55
src/FileSystem.cxx Normal file
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@ -0,0 +1,55 @@
/*
* Copyright (C) 2003-2013 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include "FileSystem.hxx"
#include <errno.h>
bool ReadLink(const Path &path, Path &result)
{
#ifdef WIN32
(void)path;
result = Path::Null();
errno = EINVAL;
return false;
#else
char buffer[MPD_PATH_MAX];
ssize_t size = readlink(path.c_str(), buffer, MPD_PATH_MAX);
int orig_errno = errno;
if (size < 0) {
result = Path::Null();
errno = orig_errno;
return false;
}
if (size >= MPD_PATH_MAX) {
result = Path::Null();
errno = ENOMEM;
return false;
}
buffer[size] = '\0';
result = Path::FromFS(buffer);
if (result.IsNull()) {
errno = ENOMEM;
return false;
}
errno = orig_errno;
return true;
#endif
}

203
src/FileSystem.hxx Normal file
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@ -0,0 +1,203 @@
/*
* Copyright (C) 2003-2013 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_FILESYSTEM_HXX
#define MPD_FILESYSTEM_HXX
#include "check.h"
#include "fd_util.h"
#include "Path.hxx"
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <assert.h>
#include <stdio.h>
namespace FOpenMode {
/**
* Open mode for reading text files.
*/
constexpr Path::const_pointer ReadText = "r";
/**
* Open mode for reading binary files.
*/
constexpr Path::const_pointer ReadBinary = "rb";
/**
* Open mode for writing text files.
*/
constexpr Path::const_pointer WriteText = "w";
/**
* Open mode for writing binary files.
*/
constexpr Path::const_pointer WriteBinary = "wb";
}
/**
* Wrapper for fopen() that uses #Path names.
*/
static inline FILE *FOpen(const Path &file, Path::const_pointer mode)
{
return fopen(file.c_str(), mode);
}
/**
* Wrapper for open_cloexec() that uses #Path names.
*/
static inline int OpenFile(const Path &file, int flags, int mode)
{
return open_cloexec(file.c_str(), flags, mode);
}
/**
* Wrapper for rename() that uses #Path names.
*/
static inline int RenameFile(const Path &oldpath, const Path &newpath)
{
return rename(oldpath.c_str(), newpath.c_str());
}
/**
* Wrapper for stat() that uses #Path names.
*/
static inline int StatFile(const Path &file, struct stat &buf)
{
return stat(file.c_str(), &buf);
}
/**
* Wrapper for unlink() that uses #Path names.
*/
static inline int UnlinkFile(const Path &file)
{
return unlink(file.c_str());
}
/**
* Wrapper for readlink() that uses #Path names.
* Unlike readlink() it returns true on success and false otherwise.
* Use errno to get error code.
*/
bool ReadLink(const Path &path, Path &result);
/**
* Wrapper for access() that uses #Path names.
*/
static inline int CheckAccess(const Path &path, int mode)
{
#ifdef WIN32
(void)path;
(void)mode;
return 0;
#else
return access(path.c_str(), mode);
#endif
}
/**
* Checks if #Path is a regular file.
*/
static inline bool CheckIsRegular(const Path &path)
{
struct stat buf;
return StatFile(path, buf) == 0 && S_ISREG(buf.st_mode);
}
/**
* Checks if #Path is a directory.
*/
static inline bool CheckIsDirectory(const Path &path)
{
struct stat buf;
return StatFile(path, buf) == 0 && S_ISDIR(buf.st_mode);
}
/**
* Checks if #Path exists.
*/
static inline bool CheckExists(const Path &path)
{
struct stat buf;
return StatFile(path, buf) == 0;
}
/**
* Reader for directory entries.
*/
class DirectoryReader {
DIR *const dirp;
dirent *ent;
public:
/**
* Creates new directory reader for the specified #dir.
*/
explicit DirectoryReader(const Path &dir)
: dirp(opendir(dir.c_str())),
ent(nullptr) {
}
DirectoryReader(const DirectoryReader &other) = delete;
DirectoryReader &operator=(const DirectoryReader &other) = delete;
/**
* Destroys this instance.
*/
~DirectoryReader() {
if (!Failed())
closedir(dirp);
}
/**
* Checks if directory failed to open.
*/
bool Failed() const {
return dirp == nullptr;
}
/**
* Checks if directory entry is available.
*/
bool HasEntry() const {
assert(!Failed());
return ent != nullptr;
}
/**
* Reads next directory entry.
*/
bool ReadEntry() {
assert(!Failed());
ent = readdir(dirp);
return HasEntry();
}
/**
* Extracts directory entry that was previously read by #ReadEntry.
*/
Path GetEntry() const {
assert(HasEntry());
return Path::FromFS(ent->d_name);
}
};
#endif