path: root/cpp/src/IceUtil/FileUtil.cpp

// **********************************************************************
//
// Copyright (c) 2003-2012 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************

#include <IceUtil/DisableWarnings.h>
#include <IceUtil/FileUtil.h>
#include <IceUtil/Unicode.h>
#include <IceUtil/Exception.h>
#include <climits>
#include <string.h>

#ifdef _WIN32
#  include <process.h>
#endif

#ifdef _WIN32
#  include <io.h>
#endif

#ifdef __BCPLUSPLUS__
#  include <dir.h>
#endif

using namespace std;

//
// Determine if path is an absolute path
//
bool
IceUtilInternal::isAbsolutePath(const string& path)
{
    size_t i = 0;
    size_t size = path.size();

    // Skip whitespace
    while(i < size && isspace(static_cast<unsigned char>(path[i])))
    {
        ++i;
    }

#ifdef _WIN32
    // We need at least 3 non whitespace character to have
    // and absolute path
    if(i + 3 > size)
    {
        return false;
    }

    // Check for X:\ path ('\' may have been converted to '/')
    if((path[i] >= 'A' && path[i] <= 'Z') || (path[i] >= 'a' && path[i] <= 'z'))
    {
        return path[i + 1] == ':' && (path[i + 2] == '\\' || path[i + 2] == '/');
    }

    // Check for UNC path
    return (path[i] == '\\' && path[i + 1] == '\\') || path[i] == '/';
#else
    if(i >= size)
    {
        return false;
    }

    return path[i] == '/';
#endif
}

//
// Determine if a directory exists.
//
bool
IceUtilInternal::directoryExists(const string& path)
{
    IceUtilInternal::structstat st;
    if(IceUtilInternal::stat(path, &st) != 0 || !S_ISDIR(st.st_mode))
    {
        return false;
    }
    return true;
}

//
// Determine if a regular file exists.
//
bool
IceUtilInternal::fileExists(const string& path)
{
    IceUtilInternal::structstat st;
    if(IceUtilInternal::stat(path, &st) != 0 || !S_ISREG(st.st_mode))
    {
        return false;
    }
    return true;
}

#ifdef _WIN32

//
// Stat
//
int
IceUtilInternal::stat(const string& path, structstat* buffer)
{
    return _wstat(IceUtil::stringToWstring(path).c_str(), buffer);
}

int
IceUtilInternal::remove(const string& path)
{
    return ::_wremove(IceUtil::stringToWstring(path).c_str());
}

int
IceUtilInternal::rename(const string& from, const string& to)
{
    return ::_wrename(IceUtil::stringToWstring(from).c_str(), IceUtil::stringToWstring(to).c_str());
}

int
IceUtilInternal::rmdir(const string& path)
{
    return ::_wrmdir(IceUtil::stringToWstring(path).c_str());
}

int
IceUtilInternal::mkdir(const string& path, int)
{
    return ::_wmkdir(IceUtil::stringToWstring(path).c_str());
}

FILE*
IceUtilInternal::fopen(const string& path, const string& mode)
{
    return ::_wfopen(IceUtil::stringToWstring(path).c_str(), IceUtil::stringToWstring(mode).c_str());
}

int
IceUtilInternal::open(const string& path, int flags)
{
    if(flags & _O_CREAT)
    {
        return ::_wopen(IceUtil::stringToWstring(path).c_str(), flags, _S_IREAD | _S_IWRITE);
    }
    else
    {
        return ::_wopen(IceUtil::stringToWstring(path).c_str(), flags);
    }
}

int
IceUtilInternal::getcwd(string& cwd)
{
    wchar_t cwdbuf[_MAX_PATH];
    if(_wgetcwd(cwdbuf, _MAX_PATH) == NULL)
    {
        return -1;
    }
    cwd = IceUtil::wstringToString(cwdbuf);
    return 0;
}

int
IceUtilInternal::unlink(const string& path)
{
    return _wunlink(IceUtil::stringToWstring(path).c_str());
}

int
IceUtilInternal::close(int fd)
{
#if defined(_MSC_VER) && (_MSC_VER >= 1400)
        return _close(fd);
#else
        return ::close(fd);
#endif
}

IceUtilInternal::FileLock::FileLock(const std::string& path) :
    _fd(INVALID_HANDLE_VALUE),
    _path(path)
{
    _fd = ::CreateFileW(IceUtil::stringToWstring(path).c_str(), GENERIC_WRITE, 0, NULL,
                        OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
    _path = path;

    if(_fd == INVALID_HANDLE_VALUE)
    {
        throw IceUtil::FileLockException(__FILE__, __LINE__, GetLastError(), _path);
    }

    if(::LockFile(_fd, 0, 0, 0, 0) == 0)
    {
        ::CloseHandle(_fd);
        throw IceUtil::FileLockException(__FILE__, __LINE__, GetLastError(), _path);
    }
    //
    // In Windows implementation we don't write the process pid to the file, as is 
    // not posible to read the file from other process while it is locked here.
    //
}

IceUtilInternal::FileLock::~FileLock()
{
    assert(_fd != INVALID_HANDLE_VALUE);
    CloseHandle(_fd);
    unlink(_path);
}

#ifdef _STLP_BEGIN_NAMESPACE
namespace
{
int
toFileFlags(ios_base::openmode mode)
{
    int flags = 0;
    if(mode & ios_base::app)
    {
        flags |= _O_APPEND;
    }
    if(mode & ios_base::trunc)
    {
        flags |= _O_TRUNC;
    }
    if(mode & ios_base::binary)
    {
        flags |= _O_BINARY;
    }
    if((mode & ios_base::in) && !(mode & ios_base::out))
    {
        flags |= _O_RDONLY;
    }
    else if((mode & ios_base::out) && !(mode & ios_base::in))
    {
        flags |= _O_WRONLY | _O_CREAT;
    }
    else 
    {
        flags |= _O_RDWR;
        if(mode & ios_base::trunc)
        {
            flags |= _O_CREAT;
        }
    }
    return flags;
}
}
#endif

IceUtilInternal::ifstream::ifstream()
#ifdef _STLP_BEGIN_NAMESPACE
    : _fd(-1)
#endif
{
}

#ifdef _STLP_BEGIN_NAMESPACE

IceUtilInternal::ifstream::ifstream(const string& path, ios_base::openmode mode) : _fd(-1)
{
    open(path, mode);
}

IceUtilInternal::ifstream::~ifstream()
{
    close();
}

void
IceUtilInternal::ifstream::close()
{
    if(!rdbuf()->close())
    {
        setstate(ios_base::failbit);
    }
    if(_fd >= 0)
    {
        _close(_fd);
    }
}

void
IceUtilInternal::ifstream::open(const string& path, ios_base::openmode mode)
{
    mode |= ifstream::in;
    _fd = IceUtilInternal::open(path, toFileFlags(mode));
    if(_fd < 0 || !rdbuf()->open(_fd, mode))
    {
        setstate(ios_base::failbit);
    }
    if(mode & (ios_base::ate || ios_base::app))
    {
        seekg(ios_base::end);
    }
}

#else

IceUtilInternal::ifstream::ifstream(const string& path, ios_base::openmode mode) : std::ifstream(IceUtil::stringToWstring(path).c_str(), mode)
{
}

void
IceUtilInternal::ifstream::open(const string& path, ios_base::openmode mode)
{
    std::ifstream::open(IceUtil::stringToWstring(path).c_str(), mode);
}

#endif

IceUtilInternal::ofstream::ofstream()
#ifdef _STLP_BEGIN_NAMESPACE
    : _fd(-1)
#endif
{
}

#ifdef _STLP_BEGIN_NAMESPACE

IceUtilInternal::ofstream::ofstream(const string& path, ios_base::openmode mode) : _fd(-1)
{
    open(path, mode);
}

IceUtilInternal::ofstream::~ofstream()
{
    close();
}

void
IceUtilInternal::ofstream::close()
{
    if(!rdbuf()->close())
    {
        setstate(ios_base::failbit);
    }
    if(_fd >= 0)
    {
        _close(_fd);
    }
}

void
IceUtilInternal::ofstream::open(const string& path, ios_base::openmode mode)
{
    mode |= ofstream::out;
    _fd = IceUtilInternal::open(path, toFileFlags(mode));
    if(_fd < 0 || !rdbuf()->open(_fd, mode))
    {
        setstate(ios_base::failbit);
    }
    if(mode & (ios_base::ate || ios_base::app))
    {
        seekp(ios_base::end);
    }
}

#else

IceUtilInternal::ofstream::ofstream(const string& path, ios_base::openmode mode) : std::ofstream(IceUtil::stringToWstring(path).c_str(), mode)
{
}

void
IceUtilInternal::ofstream::open(const string& path, ios_base::openmode mode)
{
    std::ofstream::open(IceUtil::stringToWstring(path).c_str(), mode);
}

#endif

#else

//
// Stat
//
int
IceUtilInternal::stat(const string& path, structstat* buffer)
{
    return ::stat(path.c_str(), buffer);
}

int
IceUtilInternal::remove(const string& path)
{
    return ::remove(path.c_str());
}

int
IceUtilInternal::rename(const string& from, const string& to)
{
    return ::rename(from.c_str(), to.c_str());
}

int
IceUtilInternal::rmdir(const string& path)
{
    return ::rmdir(path.c_str());
}

int
IceUtilInternal::mkdir(const string& path, int perm)
{
    return ::mkdir(path.c_str(), perm);
}

FILE*
IceUtilInternal::fopen(const string& path, const string& mode)
{
    return ::fopen(path.c_str(), mode.c_str());
}

int
IceUtilInternal::open(const string& path, int flags)
{
    if(flags & O_CREAT)
    {
        // By default, create with rw-rw-rw- modified by the user's umask (same as fopen).
        return ::open(path.c_str(), flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
    }
    else
    {
        return ::open(path.c_str(), flags);
    }
}

int
IceUtilInternal::getcwd(string& cwd)
{
    char cwdbuf[PATH_MAX];
    if(::getcwd(cwdbuf, PATH_MAX) == NULL)
    {
        return -1;
    }
    cwd = cwdbuf;
    return 0;
}

int
IceUtilInternal::unlink(const string& path)
{
    return ::unlink(path.c_str());
}

int
IceUtilInternal::close(int fd)
{
    return ::close(fd);
}

IceUtilInternal::FileLock::FileLock(const std::string& path) :
    _fd(-1),
    _path(path)
{
    _fd = ::open(path.c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
    if(_fd < 0)
    {
        throw IceUtil::FileLockException(__FILE__, __LINE__, errno, _path);
    }

    struct ::flock lock;
    lock.l_type = F_WRLCK; // Write lock
    lock.l_whence = SEEK_SET; // Begining of file
    lock.l_start = 0;
    lock.l_len = 0;
    
    //
    // F_SETLK tells fcntl to not block if it cannot 
    // acquire the lock, if the lock cannot be acquired 
    // it returns -1 without wait.
    //
    if(::fcntl(_fd, F_SETLK, &lock) == -1)
    {
        IceUtil::FileLockException ex(__FILE__, __LINE__, errno, _path);
        close(_fd);
        throw ex;
    }

    //
    // If there is an error after here, we close the fd,
    // to release the lock.
    //
    
    //
    // Now that we have acquire an excluxive write lock,
    // write the process pid there.
    //
    ostringstream os;
    os << getpid();
    
    if(write(_fd, os.str().c_str(), os.str().size()) == -1)
    {
        IceUtil::FileLockException ex(__FILE__, __LINE__, errno, _path);
        close(_fd);
        throw ex;
    }
}

IceUtilInternal::FileLock::~FileLock()
{
    assert(_fd > -1);
    unlink(_path);
}

IceUtilInternal::ifstream::ifstream()
{
}

IceUtilInternal::ifstream::ifstream(const string& path, ios_base::openmode mode) : std::ifstream(path.c_str(), mode)
{
}

void
IceUtilInternal::ifstream::open(const string& path, ios_base::openmode mode)
{
    std::ifstream::open(path.c_str(), mode);
}

IceUtilInternal::ofstream::ofstream()
{
}

IceUtilInternal::ofstream::ofstream(const string& path, ios_base::openmode mode) : std::ofstream(path.c_str(), mode)
{
}

void
IceUtilInternal::ofstream::open(const string& path, ios_base::openmode mode)
{
    std::ofstream::open(path.c_str(), mode);
}

#endif