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rvargas@google.comb1ae3192013-11-28 10:31:31 +09001// 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
rvargas@chromium.org12938d72013-12-04 09:46:32 +09005#include "base/files/file.h"
rvargas@google.comb1ae3192013-11-28 10:31:31 +09006
rvargas@google.comb1ae3192013-11-28 10:31:31 +09007#include <errno.h>
rvargas@chromium.org12938d72013-12-04 09:46:32 +09008#include <fcntl.h>
rvargas@google.comb1ae3192013-11-28 10:31:31 +09009#include <sys/stat.h>
10#include <unistd.h>
11
12#include "base/files/file_path.h"
pasko63cb6792014-11-18 22:31:36 +090013#include "base/files/file_posix_hooks_internal.h"
rvargas@google.comb1ae3192013-11-28 10:31:31 +090014#include "base/logging.h"
15#include "base/metrics/sparse_histogram.h"
16#include "base/posix/eintr_wrapper.h"
17#include "base/strings/utf_string_conversions.h"
18#include "base/threading/thread_restrictions.h"
19
20#if defined(OS_ANDROID)
21#include "base/os_compat_android.h"
22#endif
23
24namespace base {
25
26// Make sure our Whence mappings match the system headers.
rvargas@chromium.org12938d72013-12-04 09:46:32 +090027COMPILE_ASSERT(File::FROM_BEGIN == SEEK_SET &&
28 File::FROM_CURRENT == SEEK_CUR &&
29 File::FROM_END == SEEK_END, whence_matches_system);
rvargas@google.comb1ae3192013-11-28 10:31:31 +090030
31namespace {
32
33#if defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL)
rvargas@google.comb1ae3192013-11-28 10:31:31 +090034static int CallFstat(int fd, stat_wrapper_t *sb) {
dbeame2a95e62015-04-24 06:42:34 +090035 ThreadRestrictions::AssertIOAllowed();
rvargas@google.comb1ae3192013-11-28 10:31:31 +090036 return fstat(fd, sb);
37}
38#else
rvargas@google.comb1ae3192013-11-28 10:31:31 +090039static int CallFstat(int fd, stat_wrapper_t *sb) {
dbeame2a95e62015-04-24 06:42:34 +090040 ThreadRestrictions::AssertIOAllowed();
rvargas@google.comb1ae3192013-11-28 10:31:31 +090041 return fstat64(fd, sb);
42}
43#endif
44
45// NaCl doesn't provide the following system calls, so either simulate them or
46// wrap them in order to minimize the number of #ifdef's in this file.
47#if !defined(OS_NACL)
48static bool IsOpenAppend(PlatformFile file) {
49 return (fcntl(file, F_GETFL) & O_APPEND) != 0;
50}
51
52static int CallFtruncate(PlatformFile file, int64 length) {
53 return HANDLE_EINTR(ftruncate(file, length));
54}
55
rvargas@google.comb1ae3192013-11-28 10:31:31 +090056static int CallFutimes(PlatformFile file, const struct timeval times[2]) {
57#ifdef __USE_XOPEN2K8
58 // futimens should be available, but futimes might not be
59 // http://pubs.opengroup.org/onlinepubs/9699919799/
60
61 timespec ts_times[2];
62 ts_times[0].tv_sec = times[0].tv_sec;
63 ts_times[0].tv_nsec = times[0].tv_usec * 1000;
64 ts_times[1].tv_sec = times[1].tv_sec;
65 ts_times[1].tv_nsec = times[1].tv_usec * 1000;
66
67 return futimens(file, ts_times);
68#else
69 return futimes(file, times);
70#endif
71}
72
rvargas@chromium.org12938d72013-12-04 09:46:32 +090073static File::Error CallFctnlFlock(PlatformFile file, bool do_lock) {
rvargas@google.comb1ae3192013-11-28 10:31:31 +090074 struct flock lock;
75 lock.l_type = F_WRLCK;
76 lock.l_whence = SEEK_SET;
77 lock.l_start = 0;
78 lock.l_len = 0; // Lock entire file.
79 if (HANDLE_EINTR(fcntl(file, do_lock ? F_SETLK : F_UNLCK, &lock)) == -1)
rvargas@chromium.org12938d72013-12-04 09:46:32 +090080 return File::OSErrorToFileError(errno);
81 return File::FILE_OK;
rvargas@google.comb1ae3192013-11-28 10:31:31 +090082}
83#else // defined(OS_NACL)
84
85static bool IsOpenAppend(PlatformFile file) {
86 // NaCl doesn't implement fcntl. Since NaCl's write conforms to the POSIX
87 // standard and always appends if the file is opened with O_APPEND, just
88 // return false here.
89 return false;
90}
91
92static int CallFtruncate(PlatformFile file, int64 length) {
93 NOTIMPLEMENTED(); // NaCl doesn't implement ftruncate.
94 return 0;
95}
96
rvargas@google.comb1ae3192013-11-28 10:31:31 +090097static int CallFutimes(PlatformFile file, const struct timeval times[2]) {
98 NOTIMPLEMENTED(); // NaCl doesn't implement futimes.
99 return 0;
100}
101
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900102static File::Error CallFctnlFlock(PlatformFile file, bool do_lock) {
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900103 NOTIMPLEMENTED(); // NaCl doesn't implement flock struct.
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900104 return File::FILE_ERROR_INVALID_OPERATION;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900105}
106#endif // defined(OS_NACL)
107
108} // namespace
109
rvargas@chromium.org527ea312014-04-05 11:39:18 +0900110void File::Info::FromStat(const stat_wrapper_t& stat_info) {
111 is_directory = S_ISDIR(stat_info.st_mode);
112 is_symbolic_link = S_ISLNK(stat_info.st_mode);
113 size = stat_info.st_size;
114
115#if defined(OS_LINUX)
116 time_t last_modified_sec = stat_info.st_mtim.tv_sec;
117 int64 last_modified_nsec = stat_info.st_mtim.tv_nsec;
118 time_t last_accessed_sec = stat_info.st_atim.tv_sec;
119 int64 last_accessed_nsec = stat_info.st_atim.tv_nsec;
120 time_t creation_time_sec = stat_info.st_ctim.tv_sec;
121 int64 creation_time_nsec = stat_info.st_ctim.tv_nsec;
122#elif defined(OS_ANDROID)
123 time_t last_modified_sec = stat_info.st_mtime;
124 int64 last_modified_nsec = stat_info.st_mtime_nsec;
125 time_t last_accessed_sec = stat_info.st_atime;
126 int64 last_accessed_nsec = stat_info.st_atime_nsec;
127 time_t creation_time_sec = stat_info.st_ctime;
128 int64 creation_time_nsec = stat_info.st_ctime_nsec;
129#elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
130 time_t last_modified_sec = stat_info.st_mtimespec.tv_sec;
131 int64 last_modified_nsec = stat_info.st_mtimespec.tv_nsec;
132 time_t last_accessed_sec = stat_info.st_atimespec.tv_sec;
133 int64 last_accessed_nsec = stat_info.st_atimespec.tv_nsec;
134 time_t creation_time_sec = stat_info.st_ctimespec.tv_sec;
135 int64 creation_time_nsec = stat_info.st_ctimespec.tv_nsec;
136#else
137 time_t last_modified_sec = stat_info.st_mtime;
138 int64 last_modified_nsec = 0;
139 time_t last_accessed_sec = stat_info.st_atime;
140 int64 last_accessed_nsec = 0;
141 time_t creation_time_sec = stat_info.st_ctime;
142 int64 creation_time_nsec = 0;
143#endif
144
145 last_modified =
146 Time::FromTimeT(last_modified_sec) +
147 TimeDelta::FromMicroseconds(last_modified_nsec /
148 Time::kNanosecondsPerMicrosecond);
149
150 last_accessed =
151 Time::FromTimeT(last_accessed_sec) +
152 TimeDelta::FromMicroseconds(last_accessed_nsec /
153 Time::kNanosecondsPerMicrosecond);
154
155 creation_time =
156 Time::FromTimeT(creation_time_sec) +
157 TimeDelta::FromMicroseconds(creation_time_nsec /
158 Time::kNanosecondsPerMicrosecond);
159}
160
pasko63cb6792014-11-18 22:31:36 +0900161// Default implementations of Protect/Unprotect hooks defined as weak symbols
162// where possible.
163void ProtectFileDescriptor(int fd) {
164}
165
166void UnprotectFileDescriptor(int fd) {
167}
168
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900169bool File::IsValid() const {
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900170 return file_.is_valid();
171}
172
173PlatformFile File::GetPlatformFile() const {
174 return file_.get();
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900175}
176
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900177PlatformFile File::TakePlatformFile() {
pasko63cb6792014-11-18 22:31:36 +0900178 if (IsValid())
179 UnprotectFileDescriptor(GetPlatformFile());
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900180 return file_.release();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900181}
182
183void File::Close() {
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900184 if (!IsValid())
185 return;
186
dbeame2a95e62015-04-24 06:42:34 +0900187 ThreadRestrictions::AssertIOAllowed();
pasko63cb6792014-11-18 22:31:36 +0900188 UnprotectFileDescriptor(GetPlatformFile());
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900189 file_.reset();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900190}
191
192int64 File::Seek(Whence whence, int64 offset) {
dbeame2a95e62015-04-24 06:42:34 +0900193 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900194 DCHECK(IsValid());
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900195
rvargas@chromium.orgba1a9542014-06-21 08:30:18 +0900196#if defined(OS_ANDROID)
197 COMPILE_ASSERT(sizeof(int64) == sizeof(off64_t), off64_t_64_bit);
198 return lseek64(file_.get(), static_cast<off64_t>(offset),
199 static_cast<int>(whence));
200#else
201 COMPILE_ASSERT(sizeof(int64) == sizeof(off_t), off_t_64_bit);
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900202 return lseek(file_.get(), static_cast<off_t>(offset),
203 static_cast<int>(whence));
rvargas@chromium.orgba1a9542014-06-21 08:30:18 +0900204#endif
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900205}
206
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900207int File::Read(int64 offset, char* data, int size) {
dbeame2a95e62015-04-24 06:42:34 +0900208 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900209 DCHECK(IsValid());
210 if (size < 0)
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900211 return -1;
212
213 int bytes_read = 0;
214 int rv;
215 do {
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900216 rv = HANDLE_EINTR(pread(file_.get(), data + bytes_read,
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900217 size - bytes_read, offset + bytes_read));
218 if (rv <= 0)
219 break;
220
221 bytes_read += rv;
222 } while (bytes_read < size);
223
224 return bytes_read ? bytes_read : rv;
225}
226
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900227int File::ReadAtCurrentPos(char* data, int size) {
dbeame2a95e62015-04-24 06:42:34 +0900228 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900229 DCHECK(IsValid());
230 if (size < 0)
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900231 return -1;
232
233 int bytes_read = 0;
234 int rv;
235 do {
hashimoto@chromium.org94f5b7d2014-04-01 07:18:09 +0900236 rv = HANDLE_EINTR(read(file_.get(), data + bytes_read, size - bytes_read));
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900237 if (rv <= 0)
238 break;
239
240 bytes_read += rv;
241 } while (bytes_read < size);
242
243 return bytes_read ? bytes_read : rv;
244}
245
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900246int File::ReadNoBestEffort(int64 offset, char* data, int size) {
dbeame2a95e62015-04-24 06:42:34 +0900247 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900248 DCHECK(IsValid());
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900249
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900250 return HANDLE_EINTR(pread(file_.get(), data, size, offset));
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900251}
252
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900253int File::ReadAtCurrentPosNoBestEffort(char* data, int size) {
dbeame2a95e62015-04-24 06:42:34 +0900254 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900255 DCHECK(IsValid());
256 if (size < 0)
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900257 return -1;
258
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900259 return HANDLE_EINTR(read(file_.get(), data, size));
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900260}
261
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900262int File::Write(int64 offset, const char* data, int size) {
dbeame2a95e62015-04-24 06:42:34 +0900263 ThreadRestrictions::AssertIOAllowed();
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900264
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900265 if (IsOpenAppend(file_.get()))
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900266 return WriteAtCurrentPos(data, size);
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900267
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900268 DCHECK(IsValid());
269 if (size < 0)
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900270 return -1;
271
272 int bytes_written = 0;
273 int rv;
274 do {
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900275 rv = HANDLE_EINTR(pwrite(file_.get(), data + bytes_written,
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900276 size - bytes_written, offset + bytes_written));
277 if (rv <= 0)
278 break;
279
280 bytes_written += rv;
281 } while (bytes_written < size);
282
283 return bytes_written ? bytes_written : rv;
284}
285
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900286int File::WriteAtCurrentPos(const char* data, int size) {
dbeame2a95e62015-04-24 06:42:34 +0900287 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900288 DCHECK(IsValid());
289 if (size < 0)
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900290 return -1;
291
292 int bytes_written = 0;
293 int rv;
294 do {
hashimoto@chromium.org94f5b7d2014-04-01 07:18:09 +0900295 rv = HANDLE_EINTR(write(file_.get(), data + bytes_written,
296 size - bytes_written));
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900297 if (rv <= 0)
298 break;
299
300 bytes_written += rv;
301 } while (bytes_written < size);
302
303 return bytes_written ? bytes_written : rv;
304}
305
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900306int File::WriteAtCurrentPosNoBestEffort(const char* data, int size) {
dbeame2a95e62015-04-24 06:42:34 +0900307 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900308 DCHECK(IsValid());
309 if (size < 0)
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900310 return -1;
311
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900312 return HANDLE_EINTR(write(file_.get(), data, size));
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900313}
314
rvargas@chromium.orge207eae2014-01-04 07:14:15 +0900315int64 File::GetLength() {
316 DCHECK(IsValid());
317
318 stat_wrapper_t file_info;
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900319 if (CallFstat(file_.get(), &file_info))
rvargas@chromium.orge207eae2014-01-04 07:14:15 +0900320 return false;
321
322 return file_info.st_size;
323}
324
325bool File::SetLength(int64 length) {
dbeame2a95e62015-04-24 06:42:34 +0900326 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900327 DCHECK(IsValid());
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900328 return !CallFtruncate(file_.get(), length);
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900329}
330
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900331bool File::SetTimes(Time last_access_time, Time last_modified_time) {
dbeame2a95e62015-04-24 06:42:34 +0900332 ThreadRestrictions::AssertIOAllowed();
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900333 DCHECK(IsValid());
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900334
335 timeval times[2];
336 times[0] = last_access_time.ToTimeVal();
337 times[1] = last_modified_time.ToTimeVal();
338
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900339 return !CallFutimes(file_.get(), times);
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900340}
341
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900342bool File::GetInfo(Info* info) {
343 DCHECK(IsValid());
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900344
345 stat_wrapper_t file_info;
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900346 if (CallFstat(file_.get(), &file_info))
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900347 return false;
348
rvargas@chromium.org527ea312014-04-05 11:39:18 +0900349 info->FromStat(file_info);
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900350 return true;
351}
352
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900353File::Error File::Lock() {
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900354 return CallFctnlFlock(file_.get(), true);
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900355}
356
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900357File::Error File::Unlock() {
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900358 return CallFctnlFlock(file_.get(), false);
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900359}
360
grt98ea39f2015-03-20 02:54:40 +0900361File File::Duplicate() {
362 if (!IsValid())
363 return File();
364
365 PlatformFile other_fd = dup(GetPlatformFile());
366 if (other_fd == -1)
367 return File(OSErrorToFileError(errno));
368
369 File other(other_fd);
370 if (async())
371 other.async_ = true;
372 return other.Pass();
373}
374
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900375// Static.
376File::Error File::OSErrorToFileError(int saved_errno) {
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900377 switch (saved_errno) {
378 case EACCES:
379 case EISDIR:
380 case EROFS:
381 case EPERM:
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900382 return FILE_ERROR_ACCESS_DENIED;
cmumford2eb66922015-03-14 04:35:02 +0900383 case EBUSY:
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900384#if !defined(OS_NACL) // ETXTBSY not defined by NaCl.
385 case ETXTBSY:
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900386#endif
cmumford2eb66922015-03-14 04:35:02 +0900387 return FILE_ERROR_IN_USE;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900388 case EEXIST:
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900389 return FILE_ERROR_EXISTS;
cmumford2eb66922015-03-14 04:35:02 +0900390 case EIO:
391 return FILE_ERROR_IO;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900392 case ENOENT:
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900393 return FILE_ERROR_NOT_FOUND;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900394 case EMFILE:
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900395 return FILE_ERROR_TOO_MANY_OPENED;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900396 case ENOMEM:
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900397 return FILE_ERROR_NO_MEMORY;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900398 case ENOSPC:
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900399 return FILE_ERROR_NO_SPACE;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900400 case ENOTDIR:
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900401 return FILE_ERROR_NOT_A_DIRECTORY;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900402 default:
403#if !defined(OS_NACL) // NaCl build has no metrics code.
404 UMA_HISTOGRAM_SPARSE_SLOWLY("PlatformFile.UnknownErrors.Posix",
405 saved_errno);
406#endif
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900407 return FILE_ERROR_FAILED;
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900408 }
409}
410
gavinpb7467662014-11-08 02:46:12 +0900411File::MemoryCheckingScopedFD::MemoryCheckingScopedFD() {
412 UpdateChecksum();
413}
414
415File::MemoryCheckingScopedFD::MemoryCheckingScopedFD(int fd) : file_(fd) {
416 UpdateChecksum();
417}
418
419File::MemoryCheckingScopedFD::~MemoryCheckingScopedFD() {}
420
421// static
422void File::MemoryCheckingScopedFD::ComputeMemoryChecksum(
423 unsigned int* out_checksum) const {
424 // Use a single iteration of a linear congruentional generator (lcg) to
425 // provide a cheap checksum unlikely to be accidentally matched by a random
426 // memory corruption.
427
428 // By choosing constants that satisfy the Hull-Duebell Theorem on lcg cycle
429 // length, we insure that each distinct fd value maps to a distinct checksum,
430 // which maximises the utility of our checksum.
431
432 // This code uses "unsigned int" throughout for its defined modular semantics,
433 // which implicitly gives us a divisor that is a power of two.
434
435 const unsigned int kMultiplier = 13035 * 4 + 1;
436 COMPILE_ASSERT(((kMultiplier - 1) & 3) == 0, pred_must_be_multiple_of_four);
437 const unsigned int kIncrement = 1595649551;
438 COMPILE_ASSERT(kIncrement & 1, must_be_coprime_to_powers_of_two);
439
440 *out_checksum =
441 static_cast<unsigned int>(file_.get()) * kMultiplier + kIncrement;
442}
443
444void File::MemoryCheckingScopedFD::Check() const {
445 unsigned int computed_checksum;
446 ComputeMemoryChecksum(&computed_checksum);
447 CHECK_EQ(file_memory_checksum_, computed_checksum) << "corrupted fd memory";
448}
449
450void File::MemoryCheckingScopedFD::UpdateChecksum() {
451 ComputeMemoryChecksum(&file_memory_checksum_);
452}
453
dbeam740120e2015-04-24 10:27:53 +0900454// NaCl doesn't implement system calls to open files directly.
455#if !defined(OS_NACL)
456// TODO(erikkay): does it make sense to support FLAG_EXCLUSIVE_* here?
457void File::DoInitialize(const FilePath& name, uint32 flags) {
458 ThreadRestrictions::AssertIOAllowed();
459 DCHECK(!IsValid());
460
461 int open_flags = 0;
462 if (flags & FLAG_CREATE)
463 open_flags = O_CREAT | O_EXCL;
464
465 created_ = false;
466
467 if (flags & FLAG_CREATE_ALWAYS) {
468 DCHECK(!open_flags);
469 DCHECK(flags & FLAG_WRITE);
470 open_flags = O_CREAT | O_TRUNC;
471 }
472
473 if (flags & FLAG_OPEN_TRUNCATED) {
474 DCHECK(!open_flags);
475 DCHECK(flags & FLAG_WRITE);
476 open_flags = O_TRUNC;
477 }
478
479 if (!open_flags && !(flags & FLAG_OPEN) && !(flags & FLAG_OPEN_ALWAYS)) {
480 NOTREACHED();
481 errno = EOPNOTSUPP;
482 error_details_ = FILE_ERROR_FAILED;
483 return;
484 }
485
486 if (flags & FLAG_WRITE && flags & FLAG_READ) {
487 open_flags |= O_RDWR;
488 } else if (flags & FLAG_WRITE) {
489 open_flags |= O_WRONLY;
490 } else if (!(flags & FLAG_READ) &&
491 !(flags & FLAG_WRITE_ATTRIBUTES) &&
492 !(flags & FLAG_APPEND) &&
493 !(flags & FLAG_OPEN_ALWAYS)) {
494 NOTREACHED();
495 }
496
497 if (flags & FLAG_TERMINAL_DEVICE)
498 open_flags |= O_NOCTTY | O_NDELAY;
499
500 if (flags & FLAG_APPEND && flags & FLAG_READ)
501 open_flags |= O_APPEND | O_RDWR;
502 else if (flags & FLAG_APPEND)
503 open_flags |= O_APPEND | O_WRONLY;
504
505 COMPILE_ASSERT(O_RDONLY == 0, O_RDONLY_must_equal_zero);
506
507 int mode = S_IRUSR | S_IWUSR;
508#if defined(OS_CHROMEOS)
509 mode |= S_IRGRP | S_IROTH;
510#endif
511
512 int descriptor = HANDLE_EINTR(open(name.value().c_str(), open_flags, mode));
513
514 if (flags & FLAG_OPEN_ALWAYS) {
515 if (descriptor < 0) {
516 open_flags |= O_CREAT;
517 if (flags & FLAG_EXCLUSIVE_READ || flags & FLAG_EXCLUSIVE_WRITE)
518 open_flags |= O_EXCL; // together with O_CREAT implies O_NOFOLLOW
519
520 descriptor = HANDLE_EINTR(open(name.value().c_str(), open_flags, mode));
521 if (descriptor >= 0)
522 created_ = true;
523 }
524 }
525
526 if (descriptor < 0) {
527 error_details_ = File::OSErrorToFileError(errno);
528 return;
529 }
530
531 if (flags & (FLAG_CREATE_ALWAYS | FLAG_CREATE))
532 created_ = true;
533
534 if (flags & FLAG_DELETE_ON_CLOSE)
535 unlink(name.value().c_str());
536
537 async_ = ((flags & FLAG_ASYNC) == FLAG_ASYNC);
538 error_details_ = FILE_OK;
539 file_.reset(descriptor);
540 ProtectFileDescriptor(descriptor);
541}
542#endif // !defined(OS_NACL)
543
tnagel7eaf4772015-04-03 19:11:46 +0900544bool File::DoFlush() {
dbeame2a95e62015-04-24 06:42:34 +0900545 ThreadRestrictions::AssertIOAllowed();
tnagel7eaf4772015-04-03 19:11:46 +0900546 DCHECK(IsValid());
547#if defined(OS_NACL)
548 NOTIMPLEMENTED(); // NaCl doesn't implement fsync.
549 return true;
550#elif defined(OS_LINUX) || defined(OS_ANDROID)
551 return !HANDLE_EINTR(fdatasync(file_.get()));
552#else
553 return !HANDLE_EINTR(fsync(file_.get()));
554#endif
555}
556
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900557void File::SetPlatformFile(PlatformFile file) {
pasko63cb6792014-11-18 22:31:36 +0900558 CHECK(!file_.is_valid());
zmo@chromium.org536b9a92014-03-18 11:39:03 +0900559 file_.reset(file);
pasko63cb6792014-11-18 22:31:36 +0900560 if (file_.is_valid())
561 ProtectFileDescriptor(GetPlatformFile());
rvargas@chromium.org12938d72013-12-04 09:46:32 +0900562}
563
rvargas@google.comb1ae3192013-11-28 10:31:31 +0900564} // namespace base