src/CFile.cpp

   1 //
   2 // This file is part of the aMule Project.
   3 //
   4 // Copyright (c) 2003-2011 aMule Team ( admin@amule.org / http://www.amule.org )
   5 // Copyright (c) 1998-2011 Vadim Zeitlin ( zeitlin@dptmaths.ens-cachan.fr )
   6 //
   7 // Any parts of this program derived from the xMule, lMule or eMule project,
   8 // or contributed by third-party developers are copyrighted by their
   9 // respective authors.
  10 //
  11 // This program is free software; you can redistribute it and/or modify
  12 // it under the terms of the GNU General Public License as published by
  13 // the Free Software Foundation; either version 2 of the License, or
  14 // (at your option) any later version.
  15 //
  16 // This program is distributed in the hope that it will be useful,
  17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 // GNU General Public License for more details.
  20 //
  21 // You should have received a copy of the GNU General Public License
  22 // along with this program; if not, write to the Free Software
  23 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
  24 //
  25
  26
  27 #include "CFile.h"              // Interface declarations.
  28 #include "Logger.h"             // Needed for AddDebugLogLineC
  29 #include <common/Path.h>        // Needed for CPath
  30
  31
  32 #ifdef HAVE_CONFIG_H
  33 #include "config.h"             // Needed for HAVE_SYS_PARAM_H
  34 #endif
  35
  36
  37 #ifdef HAVE_SYS_PARAM_H
  38 #include <sys/param.h>
  39 #endif
  40
  41 // standard
  42 #if defined(__WINDOWS__ ) && !defined(__GNUWIN32__) && !defined(__WXWINE__) && !defined(__WXMICROWIN__)
  43 #       include <io.h>
  44 #       ifndef __SALFORDC__
  45 #               define   WIN32_LEAN_AND_MEAN
  46 #               define   NOSERVICE
  47 #               define   NOIME
  48 #               define   NOATOM
  49 #               define   NOGDI
  50 #               define   NOGDICAPMASKS
  51 #               define   NOMETAFILE
  52 #ifndef NOMINMAX
  53         #define   NOMINMAX
  54 #endif
  55 #               define   NOMSG
  56 #               define   NOOPENFILE
  57 #               define   NORASTEROPS
  58 #               define   NOSCROLL
  59 #               define   NOSOUND
  60 #               define   NOSYSMETRICS
  61 #               define   NOTEXTMETRIC
  62 #               define   NOWH
  63 #               define   NOCOMM
  64 #               define   NOKANJI
  65 #               define   NOCRYPT
  66 #               define   NOMCX
  67 #       endif
  68 #elif (defined(__UNIX__) || defined(__GNUWIN32__))
  69 #       ifdef __GNUWIN32__
  70 #               include <windows.h>
  71 #       endif
  72 #elif (defined(__WXPM__))
  73 #       include <io.h>
  74 #elif (defined(__WXSTUBS__))
  75         // Have to ifdef this for different environments
  76 #       include <io.h>
  77 #elif (defined(__WXMAC__))
  78 #if __MSL__ < 0x6000
  79 int access( const char *path, int mode ) { return 0 ; }
  80 #else
  81 int _access( const char *path, int mode ) { return 0 ; }
  82 #endif
  83 char* mktemp( char * path ) { return path ;}
  84 #       include <stat.h>
  85 #else
  86 #       error  "Please specify the header with file functions declarations."
  87 #endif  //Win/UNIX
  88
  89 // there is no distinction between text and binary files under Unix, so define
  90 // O_BINARY as 0 if the system headers don't do it already
  91 #if defined(__UNIX__) && !defined(O_BINARY)
  92 #       define   O_BINARY    (0)
  93 #endif  //__UNIX__
  94
  95 #ifdef __WINDOWS__
  96 #include <wx/msw/mslu.h>
  97 #endif
  98
  99
 100 // The following defines handle different names across platforms,
 101 // and ensures that we use 64b IO on windows (only 32b by default).
 102 #ifdef __WINDOWS__
 103         #define FLUSH_FD(x)                     _commit(x)
 104         #define SEEK_FD(x, y, z)                _lseeki64(x, y, z)
 105         #define TELL_FD(x)                      _telli64(x)
 106
 107         #if (__MSVCRT_VERSION__ < 0x0601)
 108                 //#warning MSCVRT-Version smaller than 6.01
 109                 #define STAT_FD(x, y)           _fstati64(x, y)
 110                 #define STAT_STRUCT             struct _stati64
 111         #else
 112                 #define STAT_FD(x, y)           _fstat64(x, y)
 113                 #define STAT_STRUCT             struct __stat64
 114         #endif
 115 #else
 116
 117 // We don't need to sync all meta-data, just the contents,
 118 // so use fdatasync when possible (see man fdatasync).
 119         #if defined(_POSIX_SYNCHRONIZED_IO) && (_POSIX_SYNCHRONIZED_IO > 0)
 120                 #define FLUSH_FD(x)             fdatasync(x)
 121         #else
 122                 #define FLUSH_FD(x)             fsync(x)
 123         #endif
 124
 125         #define SEEK_FD(x, y, z)                lseek(x, y, z)
 126         #define TELL_FD(x)                      wxTell(x)
 127         #define STAT_FD(x, y)                   fstat(x, y)
 128         #define STAT_STRUCT                     struct stat
 129 #endif
 130
 131
 132 // This function is used to check if a syscall failed, in that case
 133 // log an appropriate message containing the errno string.
 134 inline void syscall_check(
 135         bool check,
 136         const CPath& filePath,
 137         const wxString& what)
 138 {
 139         if (!check) {
 140                 AddDebugLogLineC(logCFile,
 141                         CFormat(wxT("Error when %s (%s): %s"))
 142                                 % what % filePath % wxSysErrorMsg());
 143         }
 144 }
 145
 146
 147 CSeekFailureException::CSeekFailureException(const wxString& desc)
 148         : CIOFailureException(wxT("SeekFailure"), desc)
 149 {}
 150
 151
 152 CFile::CFile()
 153         : m_fd(fd_invalid), m_safeWrite(false)
 154 {}
 155
 156
 157 CFile::CFile(const CPath& fileName, OpenMode mode)
 158         : m_fd(fd_invalid)
 159 {
 160         Open(fileName, mode);
 161 }
 162
 163
 164 CFile::CFile(const wxString& fileName, OpenMode mode)
 165         : m_fd(fd_invalid)
 166 {
 167         Open(fileName, mode);
 168 }
 169
 170
 171 CFile::~CFile()
 172 {
 173         if (IsOpened()) {
 174                 // If the writing gets aborted, dtor is still called.
 175                 // In this case do NOT replace the original file with the
 176                 // probably broken new one!
 177                 m_safeWrite = false;
 178                 Close();
 179         }
 180 }
 181
 182
 183 int CFile::fd() const
 184 {
 185         return m_fd;
 186 }
 187
 188
 189 bool CFile::IsOpened() const
 190 {
 191         return m_fd != fd_invalid;
 192 }
 193
 194
 195 const CPath& CFile::GetFilePath() const
 196 {
 197         return m_filePath;
 198 }
 199
 200
 201 bool CFile::Create(const CPath& path, bool overwrite, int accessMode)
 202 {
 203         if (!overwrite && path.FileExists()) {
 204                 return false;
 205         }
 206
 207         return Open(path, write, accessMode);
 208 }
 209
 210 bool CFile::Create(const wxString& path, bool overwrite, int accessMode)
 211 {
 212         return Create(CPath(path), overwrite, accessMode);
 213 }
 214
 215
 216 bool CFile::Open(const wxString& fileName, OpenMode mode, int accessMode)
 217 {
 218         MULE_VALIDATE_PARAMS(fileName.Length(), wxT("CFile: Cannot open, empty path."));
 219
 220         return Open(CPath(fileName), mode, accessMode);
 221 }
 222
 223
 224 bool CFile::Open(const CPath& fileName, OpenMode mode, int accessMode)
 225 {
 226         MULE_VALIDATE_PARAMS(fileName.IsOk(), wxT("CFile: Cannot open, empty path."));
 227
 228         if (IsOpened()) {
 229                 Close();
 230         }
 231
 232         m_safeWrite = false;
 233         m_filePath = fileName;
 234
 235 #ifdef __linux__
 236         int flags = O_BINARY | O_LARGEFILE;
 237 #else
 238         int flags = O_BINARY;
 239 #endif
 240         switch ( mode ) {
 241                 case read:
 242                         flags |= O_RDONLY;
 243                         break;
 244
 245                 case write_append:
 246                         if (fileName.FileExists())
 247                         {
 248                                 flags |= O_WRONLY | O_APPEND;
 249                                 break;
 250                         }
 251                         //else: fall through as write_append is the same as write if the
 252                         //      file doesn't exist
 253
 254                 case write:
 255                         flags |= O_WRONLY | O_CREAT | O_TRUNC;
 256                         break;
 257
 258                 case write_safe:
 259                         flags |= O_WRONLY | O_CREAT | O_TRUNC;
 260                         m_filePath = m_filePath.AppendExt(wxT(".new"));
 261                         m_safeWrite = true;
 262                         break;
 263
 264                 case write_excl:
 265                         flags |= O_WRONLY | O_CREAT | O_EXCL;
 266                         break;
 267
 268                 case read_write:
 269                         flags |= O_RDWR;
 270                 break;
 271         }
 272
 273         // Windows needs wide character file names
 274 #ifdef __WINDOWS__
 275         m_fd = _wopen(m_filePath.GetRaw().c_str(), flags, accessMode);
 276 #else
 277         Unicode2CharBuf tmpFileName = filename2char(m_filePath.GetRaw());
 278         wxASSERT_MSG(tmpFileName, wxT("Convertion failed in CFile::Open"));
 279         m_fd = open(tmpFileName, flags, accessMode);
 280 #endif
 281         syscall_check(m_fd != fd_invalid, m_filePath, wxT("opening file"));
 282
 283         return IsOpened();
 284 }
 285
 286
 287 void CFile::Reopen(OpenMode mode)
 288 {
 289         if (!Open(m_filePath, mode)) {
 290                 throw CIOFailureException(wxString(wxT("Error reopening file")));
 291         }
 292 }
 293
 294
 295 bool CFile::Close()
 296 {
 297         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot close closed file."));
 298
 299         bool closed = (close(m_fd) != -1);
 300         syscall_check(closed, m_filePath, wxT("closing file"));
 301
 302         m_fd = fd_invalid;
 303
 304         if (m_safeWrite) {
 305                 CPath filePathTemp(m_filePath);
 306                 m_filePath = m_filePath.RemoveExt();    // restore m_filePath for Reopen()
 307                 if (closed) {
 308                         closed = CPath::RenameFile(filePathTemp, m_filePath, true);
 309                 }
 310         }
 311
 312         return closed;
 313 }
 314
 315
 316 bool CFile::Flush()
 317 {
 318         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot flush closed file."));
 319
 320         bool flushed = (FLUSH_FD(m_fd) != -1);
 321         syscall_check(flushed, m_filePath, wxT("flushing file"));
 322
 323         return flushed;
 324 }
 325
 326
 327 sint64 CFile::doRead(void* buffer, size_t count) const
 328 {
 329         MULE_VALIDATE_PARAMS(buffer, wxT("CFile: Invalid buffer in read operation."));
 330         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot read from closed file."));
 331
 332         size_t totalRead = 0;
 333         while (totalRead < count) {
 334                 int current = ::read(m_fd, (char*)buffer + totalRead, count - totalRead);
 335
 336                 if (current == -1) {
 337                         // Read error, nothing we can do other than abort.
 338                         throw CIOFailureException(wxString(wxT("Error reading from file: ")) + wxSysErrorMsg());
 339                 } else if ((totalRead + current < count) && Eof()) {
 340                         // We may fail to read the specified count in a couple
 341                         // of situations: EOF and interrupts. The check for EOF
 342                         // is needed to avoid inf. loops.
 343                         break;
 344                 }
 345
 346                 totalRead += current;
 347         }
 348
 349         return totalRead;
 350 }
 351
 352
 353 sint64 CFile::doWrite(const void* buffer, size_t nCount)
 354 {
 355         MULE_VALIDATE_PARAMS(buffer, wxT("CFile: Invalid buffer in write operation."));
 356         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot write to closed file."));
 357
 358         sint64 result = ::write(m_fd, buffer, nCount);
 359
 360         if (result != (sint64)nCount) {
 361                 throw CIOFailureException(wxString(wxT("Error writing to file: ")) + wxSysErrorMsg());
 362         }
 363
 364         return result;
 365 }
 366
 367
 368 sint64 CFile::doSeek(sint64 offset) const
 369 {
 370         MULE_VALIDATE_STATE(IsOpened(), wxT("Cannot seek on closed file."));
 371         MULE_VALIDATE_PARAMS(offset >= 0, wxT("Invalid position, must be positive."));
 372
 373         sint64 result = SEEK_FD(m_fd, offset, SEEK_SET);
 374
 375         if (result == offset) {
 376                 return result;
 377         } else if (result == wxInvalidOffset) {
 378                 throw CSeekFailureException(wxString(wxT("Seeking failed: ")) + wxSysErrorMsg());
 379         } else {
 380                 throw CSeekFailureException(wxT("Seeking returned incorrect position"));
 381         }
 382 }
 383
 384
 385 uint64 CFile::GetPosition() const
 386 {
 387         MULE_VALIDATE_STATE(IsOpened(), wxT("Cannot get position in closed file."));
 388
 389         sint64 pos = TELL_FD(m_fd);
 390         if (pos == wxInvalidOffset) {
 391                 throw CSeekFailureException(wxString(wxT("Failed to retrieve position in file: ")) + wxSysErrorMsg());
 392         }
 393
 394         return pos;
 395 }
 396
 397
 398 uint64 CFile::GetLength() const
 399 {
 400         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot get length of closed file."));
 401
 402         STAT_STRUCT buf;
 403         if (STAT_FD(m_fd, &buf) == -1) {
 404                 throw CIOFailureException(wxString(wxT("Failed to retrieve length of file: ")) + wxSysErrorMsg());
 405         }
 406
 407         return buf.st_size;
 408 }
 409
 410
 411 uint64 CFile::GetAvailable() const
 412 {
 413         const uint64 length = GetLength();
 414         const uint64 position = GetPosition();
 415
 416         // Safely handle seeking past EOF
 417         if (position < length) {
 418                 return length - position;
 419         }
 420
 421         // File is at or after EOF
 422         return 0;
 423 }
 424
 425
 426 bool CFile::SetLength(uint64 new_len)
 427 {
 428         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot set length when no file is open."));
 429
 430 #ifdef __WINDOWS__
 431 #ifdef _MSC_VER
 432 // MSVC has a 64bit version
 433         bool result = _chsize_s(m_fd, new_len) == 0;
 434 #else
 435 // MingW has an old runtime without it
 436         bool result = chsize(m_fd, new_len) == 0;
 437 #endif
 438 #else
 439         bool result = ftruncate(m_fd, new_len) != -1;
 440 #endif
 441
 442         syscall_check(result, m_filePath, wxT("truncating file"));
 443
 444         return result;
 445 }
 446 // File_checked_for_headers