base/platform_file_posix.cc

   1 // Copyright (c) 2009 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/platform_file.h"
   6
   7 #include <fcntl.h>
   8 #include <errno.h>
   9 #include <sys/stat.h>
  10
  11 #include "base/file_path.h"
  12 #include "base/logging.h"
  13 #include "base/utf_string_conversions.h"
  14
  15 namespace base {
  16
  17 // TODO(erikkay): does it make sense to support PLATFORM_FILE_EXCLUSIVE_* here?
  18 PlatformFile CreatePlatformFile(const FilePath& name, int flags,
  19                                 bool* created) {
  20   int open_flags = 0;
  21   if (flags & PLATFORM_FILE_CREATE)
  22     open_flags = O_CREAT | O_EXCL;
  23
  24   if (flags & PLATFORM_FILE_CREATE_ALWAYS) {
  25     DCHECK(!open_flags);
  26     open_flags = O_CREAT | O_TRUNC;
  27   }
  28
  29   if (!open_flags && !(flags & PLATFORM_FILE_OPEN) &&
  30       !(flags & PLATFORM_FILE_OPEN_ALWAYS)) {
  31     NOTREACHED();
  32     errno = EOPNOTSUPP;
  33     return kInvalidPlatformFileValue;
  34   }
  35
  36   if (flags & PLATFORM_FILE_WRITE && flags & PLATFORM_FILE_READ) {
  37     open_flags |= O_RDWR;
  38   } else if (flags & PLATFORM_FILE_WRITE) {
  39     open_flags |= O_WRONLY;
  40   } else if (!(flags & PLATFORM_FILE_READ)) {
  41     NOTREACHED();
  42   }
  43
  44   DCHECK(O_RDONLY == 0);
  45
  46   int descriptor = open(name.value().c_str(), open_flags, S_IRUSR | S_IWUSR);
  47
  48   if (flags & PLATFORM_FILE_OPEN_ALWAYS) {
  49     if (descriptor > 0) {
  50       if (created)
  51         *created = false;
  52     } else {
  53       open_flags |= O_CREAT;
  54       if (flags & PLATFORM_FILE_EXCLUSIVE_READ ||
  55           flags & PLATFORM_FILE_EXCLUSIVE_WRITE) {
  56         open_flags |= O_EXCL;   // together with O_CREAT implies O_NOFOLLOW
  57       }
  58       descriptor = open(name.value().c_str(), open_flags, S_IRUSR | S_IWUSR);
  59       if (created && descriptor > 0)
  60         *created = true;
  61     }
  62   }
  63
  64   if ((descriptor > 0) && (flags & PLATFORM_FILE_DELETE_ON_CLOSE)) {
  65     unlink(name.value().c_str());
  66   }
  67
  68   return descriptor;
  69 }
  70
  71 PlatformFile CreatePlatformFile(const std::wstring& name, int flags,
  72                                 bool* created) {
  73   return CreatePlatformFile(FilePath::FromWStringHack(name), flags, created);
  74 }
  75
  76 bool ClosePlatformFile(PlatformFile file) {
  77   return close(file);
  78 }
  79
  80 }  // namespace base