platform_file_posix.cc revision c7f5f8508d98d5952d42ed7648c2a8f30a4da156 
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
15namespace base {
16
17// TODO(erikkay): does it make sense to support PLATFORM_FILE_EXCLUSIVE_* here?
18PlatformFile 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
71PlatformFile CreatePlatformFile(const std::wstring& name, int flags,
72                                bool* created) {
73  return CreatePlatformFile(FilePath::FromWStringHack(name), flags, created);
74}
75
76bool ClosePlatformFile(PlatformFile file) {
77  return close(file);
78}
79
80}  // namespace base
81