// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/files/file.h"
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/metrics/sparse_histogram.h"
// TODO(rvargas): remove this (needed for kInvalidPlatformFileValue).
#include "base/platform_file.h"
#include "base/posix/eintr_wrapper.h"
#include "base/strings/utf_string_conversions.h"
#include "base/threading/thread_restrictions.h"
#if defined(OS_ANDROID)
#include "base/os_compat_android.h"
#endif
namespace base {
// Make sure our Whence mappings match the system headers.
COMPILE_ASSERT(File::FROM_BEGIN == SEEK_SET &&
File::FROM_CURRENT == SEEK_CUR &&
File::FROM_END == SEEK_END, whence_matches_system);
namespace {
#if defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL)
typedef struct stat stat_wrapper_t;
static int CallFstat(int fd, stat_wrapper_t *sb) {
base::ThreadRestrictions::AssertIOAllowed();
return fstat(fd, sb);
}
#else
typedef struct stat64 stat_wrapper_t;
static int CallFstat(int fd, stat_wrapper_t *sb) {
base::ThreadRestrictions::AssertIOAllowed();
return fstat64(fd, sb);
}
#endif
// NaCl doesn't provide the following system calls, so either simulate them or
// wrap them in order to minimize the number of #ifdef's in this file.
#if !defined(OS_NACL)
static bool IsOpenAppend(PlatformFile file) {
return (fcntl(file, F_GETFL) & O_APPEND) != 0;
}
static int CallFtruncate(PlatformFile file, int64 length) {
return HANDLE_EINTR(ftruncate(file, length));
}
static int CallFsync(PlatformFile file) {
return HANDLE_EINTR(fsync(file));
}
static int CallFutimes(PlatformFile file, const struct timeval times[2]) {
#ifdef __USE_XOPEN2K8
// futimens should be available, but futimes might not be
// http://pubs.opengroup.org/onlinepubs/9699919799/
timespec ts_times[2];
ts_times[0].tv_sec = times[0].tv_sec;
ts_times[0].tv_nsec = times[0].tv_usec * 1000;
ts_times[1].tv_sec = times[1].tv_sec;
ts_times[1].tv_nsec = times[1].tv_usec * 1000;
return futimens(file, ts_times);
#else
return futimes(file, times);
#endif
}
static File::Error CallFctnlFlock(PlatformFile file, bool do_lock) {
struct flock lock;
lock.l_type = F_WRLCK;
lock.l_whence = SEEK_SET;
lock.l_start = 0;
lock.l_len = 0; // Lock entire file.
if (HANDLE_EINTR(fcntl(file, do_lock ? F_SETLK : F_UNLCK, &lock)) == -1)
return File::OSErrorToFileError(errno);
return File::FILE_OK;
}
#else // defined(OS_NACL)
static bool IsOpenAppend(PlatformFile file) {
// NaCl doesn't implement fcntl. Since NaCl's write conforms to the POSIX
// standard and always appends if the file is opened with O_APPEND, just
// return false here.
return false;
}
static int CallFtruncate(PlatformFile file, int64 length) {
NOTIMPLEMENTED(); // NaCl doesn't implement ftruncate.
return 0;
}
static int CallFsync(PlatformFile file) {
NOTIMPLEMENTED(); // NaCl doesn't implement fsync.
return 0;
}
static int CallFutimes(PlatformFile file, const struct timeval times[2]) {
NOTIMPLEMENTED(); // NaCl doesn't implement futimes.
return 0;
}
static File::Error CallFctnlFlock(PlatformFile file, bool do_lock) {
NOTIMPLEMENTED(); // NaCl doesn't implement flock struct.
return File::FILE_ERROR_INVALID_OPERATION;
}
#endif // defined(OS_NACL)
} // namespace
// NaCl doesn't implement system calls to open files directly.
#if !defined(OS_NACL)
// TODO(erikkay): does it make sense to support FLAG_EXCLUSIVE_* here?
void File::CreateBaseFileUnsafe(const FilePath& name, uint32 flags) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(!IsValid());
DCHECK(!(flags & FLAG_ASYNC));
int open_flags = 0;
if (flags & FLAG_CREATE)
open_flags = O_CREAT | O_EXCL;
created_ = false;
if (flags & FLAG_CREATE_ALWAYS) {
DCHECK(!open_flags);
open_flags = O_CREAT | O_TRUNC;
}
if (flags & FLAG_OPEN_TRUNCATED) {
DCHECK(!open_flags);
DCHECK(flags & FLAG_WRITE);
open_flags = O_TRUNC;
}
if (!open_flags && !(flags & FLAG_OPEN) && !(flags & FLAG_OPEN_ALWAYS)) {
NOTREACHED();
errno = EOPNOTSUPP;
error_ = FILE_ERROR_FAILED;
return;
}
if (flags & FLAG_WRITE && flags & FLAG_READ) {
open_flags |= O_RDWR;
} else if (flags & FLAG_WRITE) {
open_flags |= O_WRONLY;
} else if (!(flags & FLAG_READ) &&
!(flags & FLAG_WRITE_ATTRIBUTES) &&
!(flags & FLAG_APPEND) &&
!(flags & FLAG_OPEN_ALWAYS)) {
NOTREACHED();
}
if (flags & FLAG_TERMINAL_DEVICE)
open_flags |= O_NOCTTY | O_NDELAY;
if (flags & FLAG_APPEND && flags & FLAG_READ)
open_flags |= O_APPEND | O_RDWR;
else if (flags & FLAG_APPEND)
open_flags |= O_APPEND | O_WRONLY;
COMPILE_ASSERT(O_RDONLY == 0, O_RDONLY_must_equal_zero);
int mode = S_IRUSR | S_IWUSR;
#if defined(OS_CHROMEOS)
mode |= S_IRGRP | S_IROTH;
#endif
int descriptor = HANDLE_EINTR(open(name.value().c_str(), open_flags, mode));
if (flags & FLAG_OPEN_ALWAYS) {
if (descriptor < 0) {
open_flags |= O_CREAT;
if (flags & FLAG_EXCLUSIVE_READ || flags & FLAG_EXCLUSIVE_WRITE)
open_flags |= O_EXCL; // together with O_CREAT implies O_NOFOLLOW
descriptor = HANDLE_EINTR(open(name.value().c_str(), open_flags, mode));
if (descriptor >= 0)
created_ = true;
}
}
if (descriptor >= 0 && (flags & (FLAG_CREATE_ALWAYS | FLAG_CREATE)))
created_ = true;
if ((descriptor >= 0) && (flags & FLAG_DELETE_ON_CLOSE))
unlink(name.value().c_str());
if (descriptor >= 0)
error_ = FILE_OK;
else
error_ = File::OSErrorToFileError(errno);
file_ = descriptor;
}
#endif // !defined(OS_NACL)
bool File::IsValid() const {
return file_ >= 0;
}
PlatformFile File::TakePlatformFile() {
PlatformFile file = file_;
file_ = kInvalidPlatformFileValue;
return file;
}
void File::Close() {
base::ThreadRestrictions::AssertIOAllowed();
if (!IsValid())
return;
if (!IGNORE_EINTR(close(file_)))
file_ = kInvalidPlatformFileValue;
}
int64 File::Seek(Whence whence, int64 offset) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
if (file_ < 0 || offset < 0)
return -1;
return lseek(file_, static_cast<off_t>(offset), static_cast<int>(whence));
}
int File::Read(int64 offset, char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
if (size < 0)
return -1;
int bytes_read = 0;
int rv;
do {
rv = HANDLE_EINTR(pread(file_, data + bytes_read,
size - bytes_read, offset + bytes_read));
if (rv <= 0)
break;
bytes_read += rv;
} while (bytes_read < size);
return bytes_read ? bytes_read : rv;
}
int File::ReadAtCurrentPos(char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
if (size < 0)
return -1;
int bytes_read = 0;
int rv;
do {
rv = HANDLE_EINTR(read(file_, data, size));
if (rv <= 0)
break;
bytes_read += rv;
} while (bytes_read < size);
return bytes_read ? bytes_read : rv;
}
int File::ReadNoBestEffort(int64 offset, char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
return HANDLE_EINTR(pread(file_, data, size, offset));
}
int File::ReadAtCurrentPosNoBestEffort(char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
if (size < 0)
return -1;
return HANDLE_EINTR(read(file_, data, size));
}
int File::Write(int64 offset, const char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
if (IsOpenAppend(file_))
return WriteAtCurrentPos(data, size);
DCHECK(IsValid());
if (size < 0)
return -1;
int bytes_written = 0;
int rv;
do {
rv = HANDLE_EINTR(pwrite(file_, data + bytes_written,
size - bytes_written, offset + bytes_written));
if (rv <= 0)
break;
bytes_written += rv;
} while (bytes_written < size);
return bytes_written ? bytes_written : rv;
}
int File::WriteAtCurrentPos(const char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
if (size < 0)
return -1;
int bytes_written = 0;
int rv;
do {
rv = HANDLE_EINTR(write(file_, data, size));
if (rv <= 0)
break;
bytes_written += rv;
} while (bytes_written < size);
return bytes_written ? bytes_written : rv;
}
int File::WriteAtCurrentPosNoBestEffort(const char* data, int size) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
if (size < 0)
return -1;
return HANDLE_EINTR(write(file_, data, size));
}
bool File::Truncate(int64 length) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
return !CallFtruncate(file_, length);
}
bool File::Flush() {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
return !CallFsync(file_);
}
bool File::SetTimes(Time last_access_time, Time last_modified_time) {
base::ThreadRestrictions::AssertIOAllowed();
DCHECK(IsValid());
timeval times[2];
times[0] = last_access_time.ToTimeVal();
times[1] = last_modified_time.ToTimeVal();
return !CallFutimes(file_, times);
}
bool File::GetInfo(Info* info) {
DCHECK(IsValid());
stat_wrapper_t file_info;
if (CallFstat(file_, &file_info))
return false;
info->is_directory = S_ISDIR(file_info.st_mode);
info->is_symbolic_link = S_ISLNK(file_info.st_mode);
info->size = file_info.st_size;
#if defined(OS_LINUX)
const time_t last_modified_sec = file_info.st_mtim.tv_sec;
const int64 last_modified_nsec = file_info.st_mtim.tv_nsec;
const time_t last_accessed_sec = file_info.st_atim.tv_sec;
const int64 last_accessed_nsec = file_info.st_atim.tv_nsec;
const time_t creation_time_sec = file_info.st_ctim.tv_sec;
const int64 creation_time_nsec = file_info.st_ctim.tv_nsec;
#elif defined(OS_ANDROID)
const time_t last_modified_sec = file_info.st_mtime;
const int64 last_modified_nsec = file_info.st_mtime_nsec;
const time_t last_accessed_sec = file_info.st_atime;
const int64 last_accessed_nsec = file_info.st_atime_nsec;
const time_t creation_time_sec = file_info.st_ctime;
const int64 creation_time_nsec = file_info.st_ctime_nsec;
#elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
const time_t last_modified_sec = file_info.st_mtimespec.tv_sec;
const int64 last_modified_nsec = file_info.st_mtimespec.tv_nsec;
const time_t last_accessed_sec = file_info.st_atimespec.tv_sec;
const int64 last_accessed_nsec = file_info.st_atimespec.tv_nsec;
const time_t creation_time_sec = file_info.st_ctimespec.tv_sec;
const int64 creation_time_nsec = file_info.st_ctimespec.tv_nsec;
#else
// TODO(gavinp): Investigate a good high resolution option for OS_NACL.
const time_t last_modified_sec = file_info.st_mtime;
const int64 last_modified_nsec = 0;
const time_t last_accessed_sec = file_info.st_atime;
const int64 last_accessed_nsec = 0;
const time_t creation_time_sec = file_info.st_ctime;
const int64 creation_time_nsec = 0;
#endif
info->last_modified =
base::Time::FromTimeT(last_modified_sec) +
base::TimeDelta::FromMicroseconds(last_modified_nsec /
base::Time::kNanosecondsPerMicrosecond);
info->last_accessed =
base::Time::FromTimeT(last_accessed_sec) +
base::TimeDelta::FromMicroseconds(last_accessed_nsec /
base::Time::kNanosecondsPerMicrosecond);
info->creation_time =
base::Time::FromTimeT(creation_time_sec) +
base::TimeDelta::FromMicroseconds(creation_time_nsec /
base::Time::kNanosecondsPerMicrosecond);
return true;
}
File::Error File::Lock() {
return CallFctnlFlock(file_, true);
}
File::Error File::Unlock() {
return CallFctnlFlock(file_, false);
}
// Static.
File::Error File::OSErrorToFileError(int saved_errno) {
switch (saved_errno) {
case EACCES:
case EISDIR:
case EROFS:
case EPERM:
return FILE_ERROR_ACCESS_DENIED;
#if !defined(OS_NACL) // ETXTBSY not defined by NaCl.
case ETXTBSY:
return FILE_ERROR_IN_USE;
#endif
case EEXIST:
return FILE_ERROR_EXISTS;
case ENOENT:
return FILE_ERROR_NOT_FOUND;
case EMFILE:
return FILE_ERROR_TOO_MANY_OPENED;
case ENOMEM:
return FILE_ERROR_NO_MEMORY;
case ENOSPC:
return FILE_ERROR_NO_SPACE;
case ENOTDIR:
return FILE_ERROR_NOT_A_DIRECTORY;
default:
#if !defined(OS_NACL) // NaCl build has no metrics code.
UMA_HISTOGRAM_SPARSE_SLOWLY("PlatformFile.UnknownErrors.Posix",
saved_errno);
#endif
return FILE_ERROR_FAILED;
}
}
void File::SetPlatformFile(PlatformFile file) {
DCHECK_EQ(file_, kInvalidPlatformFileValue);
file_ = file;
}
} // namespace base