base/files/file_win.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/files/file.h"
   6
   7 #include <io.h>
   8
   9 #include "base/logging.h"
  10 #include "base/metrics/sparse_histogram.h"
  11 #include "base/threading/thread_restrictions.h"
  12
  13 namespace base {
  14
  15 // Make sure our Whence mappings match the system headers.
  16 COMPILE_ASSERT(File::FROM_BEGIN   == FILE_BEGIN &&
  17                File::FROM_CURRENT == FILE_CURRENT &&
  18                File::FROM_END     == FILE_END, whence_matches_system);
  19
  20 bool File::IsValid() const {
  21   return file_.IsValid();
  22 }
  23
  24 PlatformFile File::GetPlatformFile() const {
  25   return file_.Get();
  26 }
  27
  28 PlatformFile File::TakePlatformFile() {
  29   return file_.Take();
  30 }
  31
  32 void File::Close() {
  33   if (!file_.IsValid())
  34     return;
  35
  36   ThreadRestrictions::AssertIOAllowed();
  37   SCOPED_FILE_TRACE("Close");
  38   file_.Close();
  39 }
  40
  41 int64 File::Seek(Whence whence, int64 offset) {
  42   ThreadRestrictions::AssertIOAllowed();
  43   DCHECK(IsValid());
  44
  45   SCOPED_FILE_TRACE_WITH_SIZE("Seek", offset);
  46
  47   LARGE_INTEGER distance, res;
  48   distance.QuadPart = offset;
  49   DWORD move_method = static_cast<DWORD>(whence);
  50   if (!SetFilePointerEx(file_.Get(), distance, &res, move_method))
  51     return -1;
  52   return res.QuadPart;
  53 }
  54
  55 int File::Read(int64 offset, char* data, int size) {
  56   ThreadRestrictions::AssertIOAllowed();
  57   DCHECK(IsValid());
  58   DCHECK(!async_);
  59   if (size < 0)
  60     return -1;
  61
  62   SCOPED_FILE_TRACE_WITH_SIZE("Read", size);
  63
  64   LARGE_INTEGER offset_li;
  65   offset_li.QuadPart = offset;
  66
  67   OVERLAPPED overlapped = {0};
  68   overlapped.Offset = offset_li.LowPart;
  69   overlapped.OffsetHigh = offset_li.HighPart;
  70
  71   DWORD bytes_read;
  72   if (::ReadFile(file_.Get(), data, size, &bytes_read, &overlapped))
  73     return bytes_read;
  74   if (ERROR_HANDLE_EOF == GetLastError())
  75     return 0;
  76
  77   return -1;
  78 }
  79
  80 int File::ReadAtCurrentPos(char* data, int size) {
  81   ThreadRestrictions::AssertIOAllowed();
  82   DCHECK(IsValid());
  83   DCHECK(!async_);
  84   if (size < 0)
  85     return -1;
  86
  87   SCOPED_FILE_TRACE_WITH_SIZE("ReadAtCurrentPos", size);
  88
  89   DWORD bytes_read;
  90   if (::ReadFile(file_.Get(), data, size, &bytes_read, NULL))
  91     return bytes_read;
  92   if (ERROR_HANDLE_EOF == GetLastError())
  93     return 0;
  94
  95   return -1;
  96 }
  97
  98 int File::ReadNoBestEffort(int64 offset, char* data, int size) {
  99   // TODO(dbeam): trace this separately?
 100   return Read(offset, data, size);
 101 }
 102
 103 int File::ReadAtCurrentPosNoBestEffort(char* data, int size) {
 104   // TODO(dbeam): trace this separately?
 105   return ReadAtCurrentPos(data, size);
 106 }
 107
 108 int File::Write(int64 offset, const char* data, int size) {
 109   ThreadRestrictions::AssertIOAllowed();
 110   DCHECK(IsValid());
 111   DCHECK(!async_);
 112
 113   SCOPED_FILE_TRACE_WITH_SIZE("Write", size);
 114
 115   LARGE_INTEGER offset_li;
 116   offset_li.QuadPart = offset;
 117
 118   OVERLAPPED overlapped = {0};
 119   overlapped.Offset = offset_li.LowPart;
 120   overlapped.OffsetHigh = offset_li.HighPart;
 121
 122   DWORD bytes_written;
 123   if (::WriteFile(file_.Get(), data, size, &bytes_written, &overlapped))
 124     return bytes_written;
 125
 126   return -1;
 127 }
 128
 129 int File::WriteAtCurrentPos(const char* data, int size) {
 130   ThreadRestrictions::AssertIOAllowed();
 131   DCHECK(IsValid());
 132   DCHECK(!async_);
 133   if (size < 0)
 134     return -1;
 135
 136   SCOPED_FILE_TRACE_WITH_SIZE("WriteAtCurrentPos", size);
 137
 138   DWORD bytes_written;
 139   if (::WriteFile(file_.Get(), data, size, &bytes_written, NULL))
 140     return bytes_written;
 141
 142   return -1;
 143 }
 144
 145 int File::WriteAtCurrentPosNoBestEffort(const char* data, int size) {
 146   return WriteAtCurrentPos(data, size);
 147 }
 148
 149 int64 File::GetLength() {
 150   ThreadRestrictions::AssertIOAllowed();
 151   DCHECK(IsValid());
 152
 153   SCOPED_FILE_TRACE("GetLength");
 154
 155   LARGE_INTEGER size;
 156   if (!::GetFileSizeEx(file_.Get(), &size))
 157     return -1;
 158
 159   return static_cast<int64>(size.QuadPart);
 160 }
 161
 162 bool File::SetLength(int64 length) {
 163   ThreadRestrictions::AssertIOAllowed();
 164   DCHECK(IsValid());
 165
 166   SCOPED_FILE_TRACE_WITH_SIZE("SetLength", length);
 167
 168   // Get the current file pointer.
 169   LARGE_INTEGER file_pointer;
 170   LARGE_INTEGER zero;
 171   zero.QuadPart = 0;
 172   if (!::SetFilePointerEx(file_.Get(), zero, &file_pointer, FILE_CURRENT))
 173     return false;
 174
 175   LARGE_INTEGER length_li;
 176   length_li.QuadPart = length;
 177   // If length > file size, SetFilePointerEx() should extend the file
 178   // with zeroes on all Windows standard file systems (NTFS, FATxx).
 179   if (!::SetFilePointerEx(file_.Get(), length_li, NULL, FILE_BEGIN))
 180     return false;
 181
 182   // Set the new file length and move the file pointer to its old position.
 183   // This is consistent with ftruncate()'s behavior, even when the file
 184   // pointer points to a location beyond the end of the file.
 185   // TODO(rvargas): Emulating ftruncate details seem suspicious and it is not
 186   // promised by the interface (nor was promised by PlatformFile). See if this
 187   // implementation detail can be removed.
 188   return ((::SetEndOfFile(file_.Get()) != FALSE) &&
 189           (::SetFilePointerEx(file_.Get(), file_pointer, NULL, FILE_BEGIN) !=
 190            FALSE));
 191 }
 192
 193 bool File::SetTimes(Time last_access_time, Time last_modified_time) {
 194   ThreadRestrictions::AssertIOAllowed();
 195   DCHECK(IsValid());
 196
 197   SCOPED_FILE_TRACE("SetTimes");
 198
 199   FILETIME last_access_filetime = last_access_time.ToFileTime();
 200   FILETIME last_modified_filetime = last_modified_time.ToFileTime();
 201   return (::SetFileTime(file_.Get(), NULL, &last_access_filetime,
 202                         &last_modified_filetime) != FALSE);
 203 }
 204
 205 bool File::GetInfo(Info* info) {
 206   ThreadRestrictions::AssertIOAllowed();
 207   DCHECK(IsValid());
 208
 209   SCOPED_FILE_TRACE("GetInfo");
 210
 211   BY_HANDLE_FILE_INFORMATION file_info;
 212   if (!GetFileInformationByHandle(file_.Get(), &file_info))
 213     return false;
 214
 215   LARGE_INTEGER size;
 216   size.HighPart = file_info.nFileSizeHigh;
 217   size.LowPart = file_info.nFileSizeLow;
 218   info->size = size.QuadPart;
 219   info->is_directory =
 220       (file_info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
 221   info->is_symbolic_link = false;  // Windows doesn't have symbolic links.
 222   info->last_modified = Time::FromFileTime(file_info.ftLastWriteTime);
 223   info->last_accessed = Time::FromFileTime(file_info.ftLastAccessTime);
 224   info->creation_time = Time::FromFileTime(file_info.ftCreationTime);
 225   return true;
 226 }
 227
 228 File::Error File::Lock() {
 229   DCHECK(IsValid());
 230
 231   SCOPED_FILE_TRACE("Lock");
 232
 233   BOOL result = LockFile(file_.Get(), 0, 0, MAXDWORD, MAXDWORD);
 234   if (!result)
 235     return OSErrorToFileError(GetLastError());
 236   return FILE_OK;
 237 }
 238
 239 File::Error File::Unlock() {
 240   DCHECK(IsValid());
 241
 242   SCOPED_FILE_TRACE("Unlock");
 243
 244   BOOL result = UnlockFile(file_.Get(), 0, 0, MAXDWORD, MAXDWORD);
 245   if (!result)
 246     return OSErrorToFileError(GetLastError());
 247   return FILE_OK;
 248 }
 249
 250 File File::Duplicate() {
 251   if (!IsValid())
 252     return File();
 253
 254   SCOPED_FILE_TRACE("Duplicate");
 255
 256   HANDLE other_handle = nullptr;
 257
 258   if (!::DuplicateHandle(GetCurrentProcess(),  // hSourceProcessHandle
 259                          GetPlatformFile(),
 260                          GetCurrentProcess(),  // hTargetProcessHandle
 261                          &other_handle,
 262                          0,  // dwDesiredAccess ignored due to SAME_ACCESS
 263                          FALSE,  // !bInheritHandle
 264                          DUPLICATE_SAME_ACCESS)) {
 265     return File(OSErrorToFileError(GetLastError()));
 266   }
 267
 268   File other(other_handle);
 269   if (async())
 270     other.async_ = true;
 271   return other.Pass();
 272 }
 273
 274 // Static.
 275 File::Error File::OSErrorToFileError(DWORD last_error) {
 276   switch (last_error) {
 277     case ERROR_SHARING_VIOLATION:
 278       return FILE_ERROR_IN_USE;
 279     case ERROR_FILE_EXISTS:
 280       return FILE_ERROR_EXISTS;
 281     case ERROR_FILE_NOT_FOUND:
 282     case ERROR_PATH_NOT_FOUND:
 283       return FILE_ERROR_NOT_FOUND;
 284     case ERROR_ACCESS_DENIED:
 285       return FILE_ERROR_ACCESS_DENIED;
 286     case ERROR_TOO_MANY_OPEN_FILES:
 287       return FILE_ERROR_TOO_MANY_OPENED;
 288     case ERROR_OUTOFMEMORY:
 289     case ERROR_NOT_ENOUGH_MEMORY:
 290       return FILE_ERROR_NO_MEMORY;
 291     case ERROR_HANDLE_DISK_FULL:
 292     case ERROR_DISK_FULL:
 293     case ERROR_DISK_RESOURCES_EXHAUSTED:
 294       return FILE_ERROR_NO_SPACE;
 295     case ERROR_USER_MAPPED_FILE:
 296       return FILE_ERROR_INVALID_OPERATION;
 297     case ERROR_NOT_READY:
 298     case ERROR_SECTOR_NOT_FOUND:
 299     case ERROR_DEV_NOT_EXIST:
 300     case ERROR_IO_DEVICE:
 301     case ERROR_FILE_CORRUPT:
 302     case ERROR_DISK_CORRUPT:
 303       return FILE_ERROR_IO;
 304     default:
 305       UMA_HISTOGRAM_SPARSE_SLOWLY("PlatformFile.UnknownErrors.Windows",
 306                                   last_error);
 307       return FILE_ERROR_FAILED;
 308   }
 309 }
 310
 311 void File::DoInitialize(const FilePath& path, uint32 flags) {
 312   ThreadRestrictions::AssertIOAllowed();
 313   DCHECK(!IsValid());
 314
 315   DWORD disposition = 0;
 316
 317   if (flags & FLAG_OPEN)
 318     disposition = OPEN_EXISTING;
 319
 320   if (flags & FLAG_CREATE) {
 321     DCHECK(!disposition);
 322     disposition = CREATE_NEW;
 323   }
 324
 325   if (flags & FLAG_OPEN_ALWAYS) {
 326     DCHECK(!disposition);
 327     disposition = OPEN_ALWAYS;
 328   }
 329
 330   if (flags & FLAG_CREATE_ALWAYS) {
 331     DCHECK(!disposition);
 332     DCHECK(flags & FLAG_WRITE);
 333     disposition = CREATE_ALWAYS;
 334   }
 335
 336   if (flags & FLAG_OPEN_TRUNCATED) {
 337     DCHECK(!disposition);
 338     DCHECK(flags & FLAG_WRITE);
 339     disposition = TRUNCATE_EXISTING;
 340   }
 341
 342   if (!disposition) {
 343     NOTREACHED();
 344     return;
 345   }
 346
 347   DWORD access = 0;
 348   if (flags & FLAG_WRITE)
 349     access = GENERIC_WRITE;
 350   if (flags & FLAG_APPEND) {
 351     DCHECK(!access);
 352     access = FILE_APPEND_DATA;
 353   }
 354   if (flags & FLAG_READ)
 355     access |= GENERIC_READ;
 356   if (flags & FLAG_WRITE_ATTRIBUTES)
 357     access |= FILE_WRITE_ATTRIBUTES;
 358   if (flags & FLAG_EXECUTE)
 359     access |= GENERIC_EXECUTE;
 360
 361   DWORD sharing = (flags & FLAG_EXCLUSIVE_READ) ? 0 : FILE_SHARE_READ;
 362   if (!(flags & FLAG_EXCLUSIVE_WRITE))
 363     sharing |= FILE_SHARE_WRITE;
 364   if (flags & FLAG_SHARE_DELETE)
 365     sharing |= FILE_SHARE_DELETE;
 366
 367   DWORD create_flags = 0;
 368   if (flags & FLAG_ASYNC)
 369     create_flags |= FILE_FLAG_OVERLAPPED;
 370   if (flags & FLAG_TEMPORARY)
 371     create_flags |= FILE_ATTRIBUTE_TEMPORARY;
 372   if (flags & FLAG_HIDDEN)
 373     create_flags |= FILE_ATTRIBUTE_HIDDEN;
 374   if (flags & FLAG_DELETE_ON_CLOSE)
 375     create_flags |= FILE_FLAG_DELETE_ON_CLOSE;
 376   if (flags & FLAG_BACKUP_SEMANTICS)
 377     create_flags |= FILE_FLAG_BACKUP_SEMANTICS;
 378
 379   file_.Set(CreateFile(path.value().c_str(), access, sharing, NULL,
 380                        disposition, create_flags, NULL));
 381
 382   if (file_.IsValid()) {
 383     error_details_ = FILE_OK;
 384     async_ = ((flags & FLAG_ASYNC) == FLAG_ASYNC);
 385
 386     if (flags & (FLAG_OPEN_ALWAYS))
 387       created_ = (ERROR_ALREADY_EXISTS != GetLastError());
 388     else if (flags & (FLAG_CREATE_ALWAYS | FLAG_CREATE))
 389       created_ = true;
 390   } else {
 391     error_details_ = OSErrorToFileError(GetLastError());
 392   }
 393 }
 394
 395 bool File::DoFlush() {
 396   ThreadRestrictions::AssertIOAllowed();
 397   DCHECK(IsValid());
 398   return ::FlushFileBuffers(file_.Get()) != FALSE;
 399 }
 400
 401 void File::SetPlatformFile(PlatformFile file) {
 402   file_.Set(file);
 403 }
 404
 405 }  // namespace base