platform_file_posix.cc revision 513209b27ff55e2841eac0e4120199c23acce758 
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/eintr_wrapper.h"
12#include "base/file_path.h"
13#include "base/logging.h"
14#include "base/utf_string_conversions.h"
15
16namespace base {
17
18#if defined(OS_OPENBSD) || defined(OS_FREEBSD) || \
19    (defined(OS_MACOSX) && \
20     MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5)
21typedef struct stat stat_wrapper_t;
22static int CallFstat(int fd, stat_wrapper_t *sb) {
23  return fstat(fd, sb);
24}
25#else
26typedef struct stat64 stat_wrapper_t;
27static int CallFstat(int fd, stat_wrapper_t *sb) {
28  return fstat64(fd, sb);
29}
30#endif
31
32// TODO(erikkay): does it make sense to support PLATFORM_FILE_EXCLUSIVE_* here?
33PlatformFile CreatePlatformFile(const FilePath& name, int flags,
34                                bool* created, PlatformFileError* error_code) {
35  int open_flags = 0;
36  if (flags & PLATFORM_FILE_CREATE)
37    open_flags = O_CREAT | O_EXCL;
38
39  if (flags & PLATFORM_FILE_CREATE_ALWAYS) {
40    DCHECK(!open_flags);
41    open_flags = O_CREAT | O_TRUNC;
42  }
43
44  if (!open_flags && !(flags & PLATFORM_FILE_OPEN) &&
45      !(flags & PLATFORM_FILE_OPEN_ALWAYS)) {
46    NOTREACHED();
47    errno = EOPNOTSUPP;
48    if (error_code)
49      *error_code = PLATFORM_FILE_ERROR_FAILED;
50    return kInvalidPlatformFileValue;
51  }
52
53  if (flags & PLATFORM_FILE_WRITE && flags & PLATFORM_FILE_READ) {
54    open_flags |= O_RDWR;
55  } else if (flags & PLATFORM_FILE_WRITE) {
56    open_flags |= O_WRONLY;
57  } else if (!(flags & PLATFORM_FILE_READ) &&
58             !(flags & PLATFORM_FILE_WRITE_ATTRIBUTES) &&
59             !(flags & PLATFORM_FILE_OPEN_ALWAYS)) {
60    NOTREACHED();
61  }
62
63  if (flags & PLATFORM_FILE_TRUNCATE) {
64    DCHECK(flags & PLATFORM_FILE_WRITE);
65    open_flags |= O_TRUNC;
66  }
67
68  DCHECK(O_RDONLY == 0);
69
70  int descriptor = open(name.value().c_str(), open_flags, S_IRUSR | S_IWUSR);
71
72  if (flags & PLATFORM_FILE_OPEN_ALWAYS) {
73    if (descriptor > 0) {
74      if (created)
75        *created = false;
76    } else {
77      open_flags |= O_CREAT;
78      if (flags & PLATFORM_FILE_EXCLUSIVE_READ ||
79          flags & PLATFORM_FILE_EXCLUSIVE_WRITE) {
80        open_flags |= O_EXCL;   // together with O_CREAT implies O_NOFOLLOW
81      }
82      descriptor = open(name.value().c_str(), open_flags, S_IRUSR | S_IWUSR);
83      if (created && descriptor > 0)
84        *created = true;
85    }
86  }
87
88  if (created && (descriptor > 0) &&
89      (flags & (PLATFORM_FILE_CREATE_ALWAYS | PLATFORM_FILE_CREATE)))
90    *created = true;
91
92  if ((descriptor > 0) && (flags & PLATFORM_FILE_DELETE_ON_CLOSE)) {
93    unlink(name.value().c_str());
94  }
95
96  if (error_code) {
97    if (descriptor >= 0)
98      *error_code = PLATFORM_FILE_OK;
99    else {
100      switch (errno) {
101        case EACCES:
102        case EISDIR:
103        case EROFS:
104        case EPERM:
105          *error_code = PLATFORM_FILE_ERROR_ACCESS_DENIED;
106          break;
107        case ETXTBSY:
108          *error_code = PLATFORM_FILE_ERROR_IN_USE;
109          break;
110        case EEXIST:
111          *error_code = PLATFORM_FILE_ERROR_EXISTS;
112          break;
113        case ENOENT:
114          *error_code = PLATFORM_FILE_ERROR_NOT_FOUND;
115          break;
116        case EMFILE:
117          *error_code = PLATFORM_FILE_ERROR_TOO_MANY_OPENED;
118          break;
119        case ENOMEM:
120          *error_code = PLATFORM_FILE_ERROR_NO_MEMORY;
121          break;
122        case ENOSPC:
123          *error_code = PLATFORM_FILE_ERROR_NO_SPACE;
124          break;
125        case ENOTDIR:
126          *error_code = PLATFORM_FILE_ERROR_NOT_A_DIRECTORY;
127          break;
128        default:
129          *error_code = PLATFORM_FILE_ERROR_FAILED;
130      }
131    }
132  }
133
134  return descriptor;
135}
136
137PlatformFile CreatePlatformFile(const std::wstring& name, int flags,
138                                bool* created) {
139  return CreatePlatformFile(FilePath::FromWStringHack(name), flags,
140                            created, NULL);
141}
142
143bool ClosePlatformFile(PlatformFile file) {
144  return !close(file);
145}
146
147int ReadPlatformFile(PlatformFile file, int64 offset, char* data, int size) {
148  if (file < 0)
149    return -1;
150
151  return HANDLE_EINTR(pread(file, data, size, offset));
152}
153
154int WritePlatformFile(PlatformFile file, int64 offset,
155                      const char* data, int size) {
156  if (file < 0)
157    return -1;
158
159  return HANDLE_EINTR(pwrite(file, data, size, offset));
160}
161
162bool TruncatePlatformFile(PlatformFile file, int64 length) {
163  return ((file >= 0) && !HANDLE_EINTR(ftruncate(file, length)));
164}
165
166bool FlushPlatformFile(PlatformFile file) {
167  return !fsync(file);
168}
169
170bool TouchPlatformFile(PlatformFile file, const base::Time& last_access_time,
171                       const base::Time& last_modified_time) {
172#ifdef ANDROID
173  // futimes() isn't actually POSIX.
174  // TODO: Check all callers to see if this needs to work correctly on Android.
175  return false;
176#else
177  if (file < 0)
178    return false;
179
180  timeval times[2];
181  times[0] = last_access_time.ToTimeVal();
182  times[1] = last_modified_time.ToTimeVal();
183  return !futimes(file, times);
184#endif
185}
186
187bool GetPlatformFileInfo(PlatformFile file, PlatformFileInfo* info) {
188  if (!info)
189    return false;
190
191  stat_wrapper_t file_info;
192  if (CallFstat(file, &file_info))
193    return false;
194
195  info->is_directory = S_ISDIR(file_info.st_mode);
196  info->size = file_info.st_size;
197  info->last_modified = base::Time::FromTimeT(file_info.st_mtime);
198  info->last_accessed = base::Time::FromTimeT(file_info.st_atime);
199  info->creation_time = base::Time::FromTimeT(file_info.st_ctime);
200  return true;
201}
202
203}  // namespace base
204