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 #if defined(__WINDOWS__) && !wxCHECK_VERSION(3, 1, 0)
  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                 /* fall through */
 255                 case write:
 256                         flags |= O_WRONLY | O_CREAT | O_TRUNC;
 257                         break;
 258
 259                 case write_safe:
 260                         flags |= O_WRONLY | O_CREAT | O_TRUNC;
 261                         m_filePath = m_filePath.AppendExt(wxT(".new"));
 262                         m_safeWrite = true;
 263                         break;
 264
 265                 case write_excl:
 266                         flags |= O_WRONLY | O_CREAT | O_EXCL;
 267                         break;
 268
 269                 case read_write:
 270                         flags |= O_RDWR;
 271                 break;
 272         }
 273
 274         // Windows needs wide character file names
 275 #ifdef __WINDOWS__
 276         m_fd = _wopen(m_filePath.GetRaw().c_str(), flags, accessMode);
 277 #else
 278         Unicode2CharBuf tmpFileName = filename2char(m_filePath.GetRaw());
 279         wxASSERT_MSG(tmpFileName, wxT("Convertion failed in CFile::Open"));
 280         m_fd = open(tmpFileName, flags, accessMode);
 281 #endif
 282         syscall_check(m_fd != fd_invalid, m_filePath, wxT("opening file"));
 283
 284         return IsOpened();
 285 }
 286
 287
 288 void CFile::Reopen(OpenMode mode)
 289 {
 290         if (!Open(m_filePath, mode)) {
 291                 throw CIOFailureException(wxString(wxT("Error reopening file")));
 292         }
 293 }
 294
 295
 296 bool CFile::Close()
 297 {
 298         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot close closed file."));
 299
 300         bool closed = (close(m_fd) != -1);
 301         syscall_check(closed, m_filePath, wxT("closing file"));
 302
 303         m_fd = fd_invalid;
 304
 305         if (m_safeWrite) {
 306                 CPath filePathTemp(m_filePath);
 307                 m_filePath = m_filePath.RemoveExt();    // restore m_filePath for Reopen()
 308                 if (closed) {
 309                         closed = CPath::RenameFile(filePathTemp, m_filePath, true);
 310                 }
 311         }
 312
 313         return closed;
 314 }
 315
 316
 317 bool CFile::Flush()
 318 {
 319         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot flush closed file."));
 320
 321         bool flushed = (FLUSH_FD(m_fd) != -1);
 322         syscall_check(flushed, m_filePath, wxT("flushing file"));
 323
 324         return flushed;
 325 }
 326
 327
 328 sint64 CFile::doRead(void* buffer, size_t count) const
 329 {
 330         MULE_VALIDATE_PARAMS(buffer, wxT("CFile: Invalid buffer in read operation."));
 331         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot read from closed file."));
 332
 333         size_t totalRead = 0;
 334         while (totalRead < count) {
 335                 int current = ::read(m_fd, (char*)buffer + totalRead, count - totalRead);
 336
 337                 if (current == -1) {
 338                         // Read error, nothing we can do other than abort.
 339                         throw CIOFailureException(wxString(wxT("Error reading from file: ")) + wxSysErrorMsg());
 340                 } else if ((totalRead + current < count) && Eof()) {
 341                         // We may fail to read the specified count in a couple
 342                         // of situations: EOF and interrupts. The check for EOF
 343                         // is needed to avoid inf. loops.
 344                         break;
 345                 }
 346
 347                 totalRead += current;
 348         }
 349
 350         return totalRead;
 351 }
 352
 353
 354 sint64 CFile::doWrite(const void* buffer, size_t nCount)
 355 {
 356         MULE_VALIDATE_PARAMS(buffer, wxT("CFile: Invalid buffer in write operation."));
 357         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot write to closed file."));
 358
 359         sint64 result = ::write(m_fd, buffer, nCount);
 360
 361         if (result != (sint64)nCount) {
 362                 throw CIOFailureException(wxString(wxT("Error writing to file: ")) + wxSysErrorMsg());
 363         }
 364
 365         return result;
 366 }
 367
 368
 369 sint64 CFile::doSeek(sint64 offset) const
 370 {
 371         MULE_VALIDATE_STATE(IsOpened(), wxT("Cannot seek on closed file."));
 372         MULE_VALIDATE_PARAMS(offset >= 0, wxT("Invalid position, must be positive."));
 373
 374         sint64 result = SEEK_FD(m_fd, offset, SEEK_SET);
 375
 376         if (result == offset) {
 377                 return result;
 378         } else if (result == wxInvalidOffset) {
 379                 throw CSeekFailureException(wxString(wxT("Seeking failed: ")) + wxSysErrorMsg());
 380         } else {
 381                 throw CSeekFailureException(wxT("Seeking returned incorrect position"));
 382         }
 383 }
 384
 385
 386 uint64 CFile::GetPosition() const
 387 {
 388         MULE_VALIDATE_STATE(IsOpened(), wxT("Cannot get position in closed file."));
 389
 390         sint64 pos = TELL_FD(m_fd);
 391         if (pos == wxInvalidOffset) {
 392                 throw CSeekFailureException(wxString(wxT("Failed to retrieve position in file: ")) + wxSysErrorMsg());
 393         }
 394
 395         return pos;
 396 }
 397
 398
 399 uint64 CFile::GetLength() const
 400 {
 401         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot get length of closed file."));
 402
 403         STAT_STRUCT buf;
 404         if (STAT_FD(m_fd, &buf) == -1) {
 405                 throw CIOFailureException(wxString(wxT("Failed to retrieve length of file: ")) + wxSysErrorMsg());
 406         }
 407
 408         return buf.st_size;
 409 }
 410
 411
 412 uint64 CFile::GetAvailable() const
 413 {
 414         const uint64 length = GetLength();
 415         const uint64 position = GetPosition();
 416
 417         // Safely handle seeking past EOF
 418         if (position < length) {
 419                 return length - position;
 420         }
 421
 422         // File is at or after EOF
 423         return 0;
 424 }
 425
 426
 427 bool CFile::SetLength(uint64 new_len)
 428 {
 429         MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot set length when no file is open."));
 430
 431 #ifdef __WINDOWS__
 432 #ifdef _MSC_VER
 433 // MSVC has a 64bit version
 434         bool result = _chsize_s(m_fd, new_len) == 0;
 435 #else
 436 // MingW has an old runtime without it
 437         bool result = chsize(m_fd, new_len) == 0;
 438 #endif
 439 #else
 440         bool result = ftruncate(m_fd, new_len) != -1;
 441 #endif
 442
 443         syscall_check(result, m_filePath, wxT("truncating file"));
 444
 445         return result;
 446 }
 447 // File_checked_for_headers