Files
SingularityViewer/indra/llcommon/llfile.h
Aleric Inglewood a7e72ceb32 AIFile bug fixes.
Compare with errno instead of rc.
Make sure errno is preserved.
2013-11-07 18:20:49 +01:00

450 lines
14 KiB
C++

/**
* @file llfile.h
* @author Michael Schlachter
* @date 2006-03-23
* @brief Declaration of cross-platform POSIX file buffer and c++
* stream classes.
*
* $LicenseInfo:firstyear=2006&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#ifndef LL_LLFILE_H
#define LL_LLFILE_H
#include <fstream>
#include <sys/stat.h>
/**
* This class provides a cross platform interface to the filesystem.
* Attempts to mostly mirror the POSIX style IO functions.
*/
typedef FILE LLFILE;
#if LL_WINDOWS
// windows version of stat function and stat data structure are called _stat
typedef struct _stat llstat;
#else
typedef struct stat llstat;
#include <ext/stdio_filebuf.h>
#include <bits/postypes.h>
#endif
#ifndef S_ISREG
# define S_ISREG(x) (((x) & S_IFMT) == S_IFREG)
#endif
#ifndef S_ISDIR
# define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
#endif
#include "llstring.h" // safe char* -> std::string conversion
class LL_COMMON_API LLFile
{
public:
// All these functions take UTF8 path/filenames.
static LLFILE* fopen(const std::string& filename,const char* accessmode); /* Flawfinder: ignore */
static LLFILE* _fsopen(const std::string& filename,const char* accessmode,int sharingFlag);
static int close(LLFILE * file);
// Singu extension: the same as below, but doesn't print a warning as to leave errno alone.
static int mkdir_nowarn(const std::string& filename, int perms);
static int rmdir_nowarn(const std::string& filename);
static int remove_nowarn(const std::string& filename);
static int rename_nowarn(const std::string& filename, const std::string& newname);
// perms is a permissions mask like 0777 or 0700. In most cases it will
// be overridden by the user's umask. It is ignored on Windows.
static int mkdir(const std::string& filename, int perms = 0700);
static int rmdir(const std::string& filename);
static int remove(const std::string& filename);
static int rename(const std::string& filename,const std::string& newname);
static int stat(const std::string& filename,llstat* file_status);
static bool isdir(const std::string& filename);
static bool isfile(const std::string& filename);
static LLFILE * _Fiopen(const std::string& filename,
std::ios::openmode mode);
static const char * tmpdir();
static std::string strerr(int errn);
static std::string strerr();
};
/**
* @brief Provides a layer of compatibility for C/POSIX.
*
* This is taken from both the GNU __gnu_cxx::stdio_filebuf extension and
* VC's basic_filebuf implementation.
* This file buffer provides extensions for working with standard C FILE*'s
* and POSIX file descriptors for platforms that support this.
*/
namespace
{
#if LL_WINDOWS
//typedef std::filebuf _Myfb;
//Singu note: Wrap around std::filebuf to override the open procedure.
// The client encodes filepaths in UTF-8, however Windows uses UTF-16 encoding natively.
// Need to convert paths to UTF-16 before calling std::filebuf::open.
struct _Myfb : public std::filebuf
{
_Myfb() : std::filebuf() {}
_Myfb(_Filet* file) : std::filebuf(file) {}
_Myt *open(const char *filename, std::ios_base::openmode mode, int prot = (int)std::ios_base::_Openprot)
{
return std::filebuf::open(utf8str_to_utf16str(filename).c_str(),mode,prot);
}
};
#else
typedef __gnu_cxx::stdio_filebuf< char > _Myfb;
typedef std::__c_file _Filet;
#endif /* LL_WINDOWS */
}
class LL_COMMON_API llstdio_filebuf : public _Myfb
{
public:
/**
* deferred initialization / destruction
*/
llstdio_filebuf() : _Myfb() {}
virtual ~llstdio_filebuf() {}
/**
* @param f An open @c FILE*.
* @param mode Same meaning as in a standard filebuf.
* @param size Optimal or preferred size of internal buffer, in chars.
* Defaults to system's @c BUFSIZ.
*
* This constructor associates a file stream buffer with an open
* C @c FILE*. The @c FILE* will not be automatically closed when the
* stdio_filebuf is closed/destroyed.
*/
llstdio_filebuf(_Filet* __f, std::ios_base::openmode __mode,
//size_t __size = static_cast<size_t>(BUFSIZ)) :
size_t __size = static_cast<size_t>(1)) :
#if LL_WINDOWS
_Myfb(__f) {}
#else
_Myfb(__f, __mode, __size) {}
#endif
/**
* @brief Opens an external file.
* @param s The name of the file.
* @param mode The open mode flags.
* @return @c this on success, NULL on failure
*
* If a file is already open, this function immediately fails.
* Otherwise it tries to open the file named @a s using the flags
* given in @a mode.
*/
//llstdio_filebuf* open(const char *_Filename,
// std::ios_base::openmode _Mode);
/**
* @param fd An open file descriptor.
* @param mode Same meaning as in a standard filebuf.
* @param size Optimal or preferred size of internal buffer, in chars.
*
* This constructor associates a file stream buffer with an open
* POSIX file descriptor. The file descriptor will be automatically
* closed when the stdio_filebuf is closed/destroyed.
*/
#if !LL_WINDOWS
llstdio_filebuf(int __fd, std::ios_base::openmode __mode,
//size_t __size = static_cast<size_t>(BUFSIZ)) :
size_t __size = static_cast<size_t>(1)) :
_Myfb(__fd, __mode, __size) {}
#endif
// *TODO: Seek the underlying c stream for better cross-platform compatibility?
#if !LL_WINDOWS
protected:
/** underflow() and uflow() functions are called to get the next
* character from the real input source when the buffer is empty.
* Buffered input uses underflow()
*/
/*virtual*/ int_type underflow();
/* Convert internal byte sequence to external, char-based
* sequence via codecvt.
*/
bool _convert_to_external(char_type*, std::streamsize);
/** The overflow() function is called to transfer characters to the
* real output destination when the buffer is full. A call to
* overflow(c) outputs the contents of the buffer plus the
* character c.
* Consume some sequence of the characters in the pending sequence.
*/
/*virtual*/ int_type overflow(int_type __c = traits_type::eof());
/** sync() flushes the underlying @c FILE* stream.
*/
/*virtual*/ int sync();
std::streamsize xsgetn(char_type*, std::streamsize);
std::streamsize xsputn(char_type const*, std::streamsize);
#endif
};
/**
* @brief Controlling input for files.
*
* This class supports reading from named files, using the inherited
* functions from std::basic_istream. To control the associated
* sequence, an instance of std::basic_filebuf (or a platform-specific derivative)
* which allows construction using a pre-exisintg file stream buffer.
* We refer to this std::basic_filebuf (or derivative) as @c sb.
*/
class LL_COMMON_API llifstream : public std::istream
{
// input stream associated with a C stream
public:
// Constructors:
/**
* @brief Default constructor.
*
* Initializes @c sb using its default constructor, and passes
* @c &sb to the base class initializer. Does not open any files
* (you haven't given it a filename to open).
*/
llifstream();
/**
* @brief Create an input file stream.
* @param Filename String specifying the filename.
* @param Mode Open file in specified mode (see std::ios_base).
*
* @c ios_base::in is automatically included in @a mode.
*/
explicit llifstream(const std::string& _Filename,
ios_base::openmode _Mode = ios_base::in);
explicit llifstream(const char* _Filename,
ios_base::openmode _Mode = ios_base::in);
/**
* @brief Create a stream using an open c file stream.
* @param File An open @c FILE*.
@param Mode Same meaning as in a standard filebuf.
@param Size Optimal or preferred size of internal buffer, in chars.
Defaults to system's @c BUFSIZ.
*/
explicit llifstream(_Filet *_File,
ios_base::openmode _Mode = ios_base::in,
//size_t _Size = static_cast<size_t>(BUFSIZ));
size_t _Size = static_cast<size_t>(1));
/**
* @brief Create a stream using an open file descriptor.
* @param fd An open file descriptor.
@param Mode Same meaning as in a standard filebuf.
@param Size Optimal or preferred size of internal buffer, in chars.
Defaults to system's @c BUFSIZ.
*/
#if !LL_WINDOWS
explicit llifstream(int __fd,
ios_base::openmode _Mode = ios_base::in,
//size_t _Size = static_cast<size_t>(BUFSIZ));
size_t _Size = static_cast<size_t>(1));
#endif
/**
* @brief The destructor does nothing.
*
* The file is closed by the filebuf object, not the formatting
* stream.
*/
virtual ~llifstream() {}
// Members:
/**
* @brief Accessing the underlying buffer.
* @return The current basic_filebuf buffer.
*
* This hides both signatures of std::basic_ios::rdbuf().
*/
llstdio_filebuf* rdbuf() const
{ return const_cast<llstdio_filebuf*>(&_M_filebuf); }
/**
* @brief Wrapper to test for an open file.
* @return @c rdbuf()->is_open()
*/
bool is_open() const;
/**
* @brief Opens an external file.
* @param Filename The name of the file.
* @param Node The open mode flags.
*
* Calls @c llstdio_filebuf::open(s,mode|in). If that function
* fails, @c failbit is set in the stream's error state.
*/
void open(const std::string& _Filename,
ios_base::openmode _Mode = ios_base::in)
{ open(_Filename.c_str(), _Mode); }
void open(const char* _Filename,
ios_base::openmode _Mode = ios_base::in);
/**
* @brief Close the file.
*
* Calls @c llstdio_filebuf::close(). If that function
* fails, @c failbit is set in the stream's error state.
*/
void close();
private:
llstdio_filebuf _M_filebuf;
};
/**
* @brief Controlling output for files.
*
* This class supports writing to named files, using the inherited
* functions from std::basic_ostream. To control the associated
* sequence, an instance of std::basic_filebuf (or a platform-specific derivative)
* which allows construction using a pre-exisintg file stream buffer.
* We refer to this std::basic_filebuf (or derivative) as @c sb.
*/
class LL_COMMON_API llofstream : public std::ostream
{
public:
// Constructors:
/**
* @brief Default constructor.
*
* Initializes @c sb using its default constructor, and passes
* @c &sb to the base class initializer. Does not open any files
* (you haven't given it a filename to open).
*/
llofstream();
/**
* @brief Create an output file stream.
* @param Filename String specifying the filename.
* @param Mode Open file in specified mode (see std::ios_base).
*
* @c ios_base::out|ios_base::trunc is automatically included in
* @a mode.
*/
explicit llofstream(const std::string& _Filename,
ios_base::openmode _Mode = ios_base::out|ios_base::trunc);
explicit llofstream(const char* _Filename,
ios_base::openmode _Mode = ios_base::out|ios_base::trunc);
/**
* @brief Create a stream using an open c file stream.
* @param File An open @c FILE*.
@param Mode Same meaning as in a standard filebuf.
@param Size Optimal or preferred size of internal buffer, in chars.
Defaults to system's @c BUFSIZ.
*/
explicit llofstream(_Filet *_File,
ios_base::openmode _Mode = ios_base::out,
//size_t _Size = static_cast<size_t>(BUFSIZ));
size_t _Size = static_cast<size_t>(1));
/**
* @brief Create a stream using an open file descriptor.
* @param fd An open file descriptor.
@param Mode Same meaning as in a standard filebuf.
@param Size Optimal or preferred size of internal buffer, in chars.
Defaults to system's @c BUFSIZ.
*/
#if !LL_WINDOWS
explicit llofstream(int __fd,
ios_base::openmode _Mode = ios_base::out,
//size_t _Size = static_cast<size_t>(BUFSIZ));
size_t _Size = static_cast<size_t>(1));
#endif
/**
* @brief The destructor does nothing.
*
* The file is closed by the filebuf object, not the formatting
* stream.
*/
virtual ~llofstream() {}
// Members:
/**
* @brief Accessing the underlying buffer.
* @return The current basic_filebuf buffer.
*
* This hides both signatures of std::basic_ios::rdbuf().
*/
llstdio_filebuf* rdbuf() const
{ return const_cast<llstdio_filebuf*>(&_M_filebuf); }
/**
* @brief Wrapper to test for an open file.
* @return @c rdbuf()->is_open()
*/
bool is_open() const;
/**
* @brief Opens an external file.
* @param Filename The name of the file.
* @param Node The open mode flags.
*
* Calls @c llstdio_filebuf::open(s,mode|out). If that function
* fails, @c failbit is set in the stream's error state.
*/
void open(const std::string& _Filename,
ios_base::openmode _Mode = ios_base::out|ios_base::trunc)
{ open(_Filename.c_str(), _Mode); }
void open(const char* _Filename,
ios_base::openmode _Mode = ios_base::out|ios_base::trunc);
/**
* @brief Close the file.
*
* Calls @c llstdio_filebuf::close(). If that function
* fails, @c failbit is set in the stream's error state.
*/
void close();
private:
llstdio_filebuf _M_filebuf;
};
/**
* @breif filesize helpers.
*
* The file size helpers are not considered particularly efficient,
* and should only be used for config files and the like -- not in a
* loop.
*/
std::streamsize LL_COMMON_API llifstream_size(llifstream& fstr);
std::streamsize LL_COMMON_API llofstream_size(llofstream& fstr);
#endif // not LL_LLFILE_H