src/base/files/file_posix.cc - gn - Git at Google

 // 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 <stdint.h>
 #include <sys/stat.h>
 #include <unistd.h>

 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/utf_string_conversions.h"
 #include "util/build_config.h"

 namespace base {

 // Make sure our Whence mappings match the system headers.
 static_assert(File::FROM_BEGIN == SEEK_SET && File::FROM_CURRENT == SEEK_CUR &&
                   File::FROM_END == SEEK_END,
               "whence mapping must match the system headers");

 namespace {

 #if defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL) || \
     defined(OS_HAIKU) || defined(OS_MSYS) || defined(OS_ZOS) ||  \
     defined(OS_ANDROID) && __ANDROID_API__ < 21 || defined(OS_SERENITY)
 int CallFstat(int fd, stat_wrapper_t* sb) {
   return fstat(fd, sb);
 }
 #else
 int CallFstat(int fd, stat_wrapper_t* sb) {
   return fstat64(fd, sb);
 }
 #endif

 // Some systems don'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_AIX)
 bool IsOpenAppend(PlatformFile file) {
   return (fcntl(file, F_GETFL) & O_APPEND) != 0;
 }

 int CallFtruncate(PlatformFile file, int64_t length) {
   return HANDLE_EINTR(ftruncate(file, length));
 }

 #if !defined(OS_FUCHSIA)
 File::Error CallFcntlFlock(PlatformFile file, bool do_lock) {
   struct flock lock;
   lock.l_type = do_lock ? F_WRLCK : F_UNLCK;
   lock.l_whence = SEEK_SET;
   lock.l_start = 0;
   lock.l_len = 0;  // Lock entire file.
   if (HANDLE_EINTR(fcntl(file, F_SETLK, &lock)) == -1)
     return File::GetLastFileError();
   return File::FILE_OK;
 }
 #endif

 #else   // !defined(OS_AIX)

 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;
 }

 int CallFtruncate(PlatformFile file, int64_t length) {
   NOTIMPLEMENTED();  // NaCl doesn't implement ftruncate.
   return 0;
 }

 File::Error CallFcntlFlock(PlatformFile file, bool do_lock) {
   NOTIMPLEMENTED();  // NaCl doesn't implement flock struct.
   return File::FILE_ERROR_INVALID_OPERATION;
 }
 #endif  // defined(OS_AIX)

 }  // namespace

 void File::Info::FromStat(const stat_wrapper_t& stat_info) {
   is_directory = S_ISDIR(stat_info.st_mode);
   is_symbolic_link = S_ISLNK(stat_info.st_mode);
   size = stat_info.st_size;

 #if defined(OS_MACOSX)
   time_t last_modified_sec = stat_info.st_mtimespec.tv_sec;
   int64_t last_modified_nsec = stat_info.st_mtimespec.tv_nsec;
   time_t last_accessed_sec = stat_info.st_atimespec.tv_sec;
   int64_t last_accessed_nsec = stat_info.st_atimespec.tv_nsec;
   time_t creation_time_sec = stat_info.st_ctimespec.tv_sec;
   int64_t creation_time_nsec = stat_info.st_ctimespec.tv_nsec;
 #elif defined(OS_AIX) || defined(OS_ZOS)
   time_t last_modified_sec = stat_info.st_mtime;
   int64_t last_modified_nsec = 0;
   time_t last_accessed_sec = stat_info.st_atime;
   int64_t last_accessed_nsec = 0;
   time_t creation_time_sec = stat_info.st_ctime;
   int64_t creation_time_nsec = 0;
 #elif defined(OS_POSIX)
   time_t last_modified_sec = stat_info.st_mtim.tv_sec;
   int64_t last_modified_nsec = stat_info.st_mtim.tv_nsec;
   time_t last_accessed_sec = stat_info.st_atim.tv_sec;
   int64_t last_accessed_nsec = stat_info.st_atim.tv_nsec;
   time_t creation_time_sec = stat_info.st_ctim.tv_sec;
   int64_t creation_time_nsec = stat_info.st_ctim.tv_nsec;
 #else
 #error
 #endif

   constexpr uint64_t kNano = 1'000'000'000;
   last_modified = last_modified_sec * kNano + last_modified_nsec;
   last_accessed = last_accessed_sec * kNano + last_accessed_nsec;
   creation_time = creation_time_sec * kNano + creation_time_nsec;
 }

 bool File::IsValid() const {
   return file_.is_valid();
 }

 PlatformFile File::GetPlatformFile() const {
   return file_.get();
 }

 PlatformFile File::TakePlatformFile() {
   return file_.release();
 }

 void File::Close() {
   if (!IsValid())
     return;

   file_.reset();
 }

 int64_t File::Seek(Whence whence, int64_t offset) {
   DCHECK(IsValid());

   static_assert(sizeof(int64_t) == sizeof(off_t), "off_t must be 64 bits");
   return lseek(file_.get(), static_cast<off_t>(offset),
                static_cast<int>(whence));
 }

 int File::Read(int64_t offset, char* data, int size) {
   DCHECK(IsValid());
   if (size < 0)
     return -1;

   int bytes_read = 0;
   int rv;
   do {
     rv = HANDLE_EINTR(pread(file_.get(), 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) {
   DCHECK(IsValid());
   if (size < 0)
     return -1;

   int bytes_read = 0;
   int rv;
   do {
     rv = HANDLE_EINTR(read(file_.get(), data + bytes_read, size - bytes_read));
     if (rv <= 0)
       break;

     bytes_read += rv;
   } while (bytes_read < size);

   return bytes_read ? bytes_read : rv;
 }

 int File::ReadNoBestEffort(int64_t offset, char* data, int size) {
   DCHECK(IsValid());
   return HANDLE_EINTR(pread(file_.get(), data, size, offset));
 }

 int File::ReadAtCurrentPosNoBestEffort(char* data, int size) {
   DCHECK(IsValid());
   if (size < 0)
     return -1;

   return HANDLE_EINTR(read(file_.get(), data, size));
 }

 int File::Write(int64_t offset, const char* data, int size) {
   if (IsOpenAppend(file_.get()))
     return WriteAtCurrentPos(data, size);

   DCHECK(IsValid());
   if (size < 0)
     return -1;

   int bytes_written = 0;
   int rv;
   do {
     rv = HANDLE_EINTR(pwrite(file_.get(), 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) {
   DCHECK(IsValid());
   if (size < 0)
     return -1;

   int bytes_written = 0;
   int rv;
   do {
     rv = HANDLE_EINTR(
         write(file_.get(), data + bytes_written, size - bytes_written));
     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) {
   DCHECK(IsValid());
   if (size < 0)
     return -1;

   return HANDLE_EINTR(write(file_.get(), data, size));
 }

 int64_t File::GetLength() {
   DCHECK(IsValid());

   stat_wrapper_t file_info;
   if (CallFstat(file_.get(), &file_info))
     return -1;

   return file_info.st_size;
 }

 bool File::SetLength(int64_t length) {
   DCHECK(IsValid());

   return !CallFtruncate(file_.get(), length);
 }

 bool File::GetInfo(Info* info) {
   DCHECK(IsValid());

   stat_wrapper_t file_info;
   if (CallFstat(file_.get(), &file_info))
     return false;

   info->FromStat(file_info);
   return true;
 }

 #if !defined(OS_FUCHSIA)
 File::Error File::Lock() {
   return CallFcntlFlock(file_.get(), true);
 }

 File::Error File::Unlock() {
   return CallFcntlFlock(file_.get(), false);
 }
 #endif

 File File::Duplicate() const {
   if (!IsValid())
     return File();

   PlatformFile other_fd = HANDLE_EINTR(dup(GetPlatformFile()));
   if (other_fd == -1)
     return File(File::GetLastFileError());

   File other(other_fd);
   return other;
 }

 // Static.
 File::Error File::OSErrorToFileError(int saved_errno) {
   switch (saved_errno) {
     case EACCES:
     case EISDIR:
     case EROFS:
     case EPERM:
       return FILE_ERROR_ACCESS_DENIED;
     case EBUSY:
     case ETXTBSY:
       return FILE_ERROR_IN_USE;
     case EEXIST:
       return FILE_ERROR_EXISTS;
     case EIO:
       return FILE_ERROR_IO;
     case ENOENT:
       return FILE_ERROR_NOT_FOUND;
     case ENFILE:  // fallthrough
     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:
       // This function should only be called for errors.
       DCHECK_NE(0, saved_errno);
       return FILE_ERROR_FAILED;
   }
 }

 void File::DoInitialize(const FilePath& path, uint32_t flags) {
   DCHECK(!IsValid());

   int open_flags = 0;
   if (flags & FLAG_CREATE)
     open_flags = O_CREAT | O_EXCL;

   if (flags & FLAG_CREATE_ALWAYS) {
     DCHECK(!open_flags);
     DCHECK(flags & FLAG_WRITE);
     open_flags = O_CREAT | O_TRUNC;
   }

   if (!open_flags && !(flags & FLAG_OPEN)) {
     NOTREACHED();
     errno = EOPNOTSUPP;
     error_details_ = 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) {
     open_flags |= O_RDONLY;
   } else {
     NOTREACHED();
   }

   int mode = S_IRUSR | S_IWUSR;
   int descriptor = HANDLE_EINTR(open(path.value().c_str(), open_flags, mode));

   if (descriptor < 0) {
     error_details_ = File::GetLastFileError();
     return;
   }

   error_details_ = FILE_OK;
   file_.reset(descriptor);
 }

 bool File::Flush() {
   DCHECK(IsValid());

 #if defined(OS_LINUX)
   return !HANDLE_EINTR(fdatasync(file_.get()));
 #else
   return !HANDLE_EINTR(fsync(file_.get()));
 #endif
 }

 void File::SetPlatformFile(PlatformFile file) {
   DCHECK(!file_.is_valid());
   file_.reset(file);
 }

 // static
 File::Error File::GetLastFileError() {
   return base::File::OSErrorToFileError(errno);
 }

 }  // namespace base
	// 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 <stdint.h>
	#include <sys/stat.h>
	#include <unistd.h>

	#include "base/logging.h"
	#include "base/posix/eintr_wrapper.h"
	#include "base/strings/utf_string_conversions.h"
	#include "util/build_config.h"

	namespace base {

	// Make sure our Whence mappings match the system headers.
	static_assert(File::FROM_BEGIN == SEEK_SET && File::FROM_CURRENT == SEEK_CUR &&
	File::FROM_END == SEEK_END,
	"whence mapping must match the system headers");

	namespace {

	#if defined(OS_BSD) \|\| defined(OS_MACOSX) \|\| defined(OS_NACL) \|\| \
	defined(OS_HAIKU) \|\| defined(OS_MSYS) \|\| defined(OS_ZOS) \|\| \
	defined(OS_ANDROID) && __ANDROID_API__ < 21 \|\| defined(OS_SERENITY)
	int CallFstat(int fd, stat_wrapper_t* sb) {
	return fstat(fd, sb);
	}
	#else
	int CallFstat(int fd, stat_wrapper_t* sb) {
	return fstat64(fd, sb);
	}
	#endif

	// Some systems don'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_AIX)
	bool IsOpenAppend(PlatformFile file) {
	return (fcntl(file, F_GETFL) & O_APPEND) != 0;
	}

	int CallFtruncate(PlatformFile file, int64_t length) {
	return HANDLE_EINTR(ftruncate(file, length));
	}

	#if !defined(OS_FUCHSIA)
	File::Error CallFcntlFlock(PlatformFile file, bool do_lock) {
	struct flock lock;
	lock.l_type = do_lock ? F_WRLCK : F_UNLCK;
	lock.l_whence = SEEK_SET;
	lock.l_start = 0;
	lock.l_len = 0; // Lock entire file.
	if (HANDLE_EINTR(fcntl(file, F_SETLK, &lock)) == -1)
	return File::GetLastFileError();
	return File::FILE_OK;
	}
	#endif

	#else // !defined(OS_AIX)

	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;
	}

	int CallFtruncate(PlatformFile file, int64_t length) {
	NOTIMPLEMENTED(); // NaCl doesn't implement ftruncate.
	return 0;
	}

	File::Error CallFcntlFlock(PlatformFile file, bool do_lock) {
	NOTIMPLEMENTED(); // NaCl doesn't implement flock struct.
	return File::FILE_ERROR_INVALID_OPERATION;
	}
	#endif // defined(OS_AIX)

	} // namespace

	void File::Info::FromStat(const stat_wrapper_t& stat_info) {
	is_directory = S_ISDIR(stat_info.st_mode);
	is_symbolic_link = S_ISLNK(stat_info.st_mode);
	size = stat_info.st_size;

	#if defined(OS_MACOSX)
	time_t last_modified_sec = stat_info.st_mtimespec.tv_sec;
	int64_t last_modified_nsec = stat_info.st_mtimespec.tv_nsec;
	time_t last_accessed_sec = stat_info.st_atimespec.tv_sec;
	int64_t last_accessed_nsec = stat_info.st_atimespec.tv_nsec;
	time_t creation_time_sec = stat_info.st_ctimespec.tv_sec;
	int64_t creation_time_nsec = stat_info.st_ctimespec.tv_nsec;
	#elif defined(OS_AIX) \|\| defined(OS_ZOS)
	time_t last_modified_sec = stat_info.st_mtime;
	int64_t last_modified_nsec = 0;
	time_t last_accessed_sec = stat_info.st_atime;
	int64_t last_accessed_nsec = 0;
	time_t creation_time_sec = stat_info.st_ctime;
	int64_t creation_time_nsec = 0;
	#elif defined(OS_POSIX)
	time_t last_modified_sec = stat_info.st_mtim.tv_sec;
	int64_t last_modified_nsec = stat_info.st_mtim.tv_nsec;
	time_t last_accessed_sec = stat_info.st_atim.tv_sec;
	int64_t last_accessed_nsec = stat_info.st_atim.tv_nsec;
	time_t creation_time_sec = stat_info.st_ctim.tv_sec;
	int64_t creation_time_nsec = stat_info.st_ctim.tv_nsec;
	#else
	#error
	#endif

	constexpr uint64_t kNano = 1'000'000'000;
	last_modified = last_modified_sec * kNano + last_modified_nsec;
	last_accessed = last_accessed_sec * kNano + last_accessed_nsec;
	creation_time = creation_time_sec * kNano + creation_time_nsec;
	}

	bool File::IsValid() const {
	return file_.is_valid();
	}

	PlatformFile File::GetPlatformFile() const {
	return file_.get();
	}

	PlatformFile File::TakePlatformFile() {
	return file_.release();
	}

	void File::Close() {
	if (!IsValid())
	return;

	file_.reset();
	}

	int64_t File::Seek(Whence whence, int64_t offset) {
	DCHECK(IsValid());

	static_assert(sizeof(int64_t) == sizeof(off_t), "off_t must be 64 bits");
	return lseek(file_.get(), static_cast<off_t>(offset),
	static_cast<int>(whence));
	}

	int File::Read(int64_t offset, char* data, int size) {
	DCHECK(IsValid());
	if (size < 0)
	return -1;

	int bytes_read = 0;
	int rv;
	do {
	rv = HANDLE_EINTR(pread(file_.get(), 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) {
	DCHECK(IsValid());
	if (size < 0)
	return -1;

	int bytes_read = 0;
	int rv;
	do {
	rv = HANDLE_EINTR(read(file_.get(), data + bytes_read, size - bytes_read));
	if (rv <= 0)
	break;

	bytes_read += rv;
	} while (bytes_read < size);

	return bytes_read ? bytes_read : rv;
	}

	int File::ReadNoBestEffort(int64_t offset, char* data, int size) {
	DCHECK(IsValid());
	return HANDLE_EINTR(pread(file_.get(), data, size, offset));
	}

	int File::ReadAtCurrentPosNoBestEffort(char* data, int size) {
	DCHECK(IsValid());
	if (size < 0)
	return -1;

	return HANDLE_EINTR(read(file_.get(), data, size));
	}

	int File::Write(int64_t offset, const char* data, int size) {
	if (IsOpenAppend(file_.get()))
	return WriteAtCurrentPos(data, size);

	DCHECK(IsValid());
	if (size < 0)
	return -1;

	int bytes_written = 0;
	int rv;
	do {
	rv = HANDLE_EINTR(pwrite(file_.get(), 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) {
	DCHECK(IsValid());
	if (size < 0)
	return -1;

	int bytes_written = 0;
	int rv;
	do {
	rv = HANDLE_EINTR(
	write(file_.get(), data + bytes_written, size - bytes_written));
	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) {
	DCHECK(IsValid());
	if (size < 0)
	return -1;

	return HANDLE_EINTR(write(file_.get(), data, size));
	}

	int64_t File::GetLength() {
	DCHECK(IsValid());

	stat_wrapper_t file_info;
	if (CallFstat(file_.get(), &file_info))
	return -1;

	return file_info.st_size;
	}

	bool File::SetLength(int64_t length) {
	DCHECK(IsValid());

	return !CallFtruncate(file_.get(), length);
	}

	bool File::GetInfo(Info* info) {
	DCHECK(IsValid());

	stat_wrapper_t file_info;
	if (CallFstat(file_.get(), &file_info))
	return false;

	info->FromStat(file_info);
	return true;
	}

	#if !defined(OS_FUCHSIA)
	File::Error File::Lock() {
	return CallFcntlFlock(file_.get(), true);
	}

	File::Error File::Unlock() {
	return CallFcntlFlock(file_.get(), false);
	}
	#endif

	File File::Duplicate() const {
	if (!IsValid())
	return File();

	PlatformFile other_fd = HANDLE_EINTR(dup(GetPlatformFile()));
	if (other_fd == -1)
	return File(File::GetLastFileError());

	File other(other_fd);
	return other;
	}

	// Static.
	File::Error File::OSErrorToFileError(int saved_errno) {
	switch (saved_errno) {
	case EACCES:
	case EISDIR:
	case EROFS:
	case EPERM:
	return FILE_ERROR_ACCESS_DENIED;
	case EBUSY:
	case ETXTBSY:
	return FILE_ERROR_IN_USE;
	case EEXIST:
	return FILE_ERROR_EXISTS;
	case EIO:
	return FILE_ERROR_IO;
	case ENOENT:
	return FILE_ERROR_NOT_FOUND;
	case ENFILE: // fallthrough
	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:
	// This function should only be called for errors.
	DCHECK_NE(0, saved_errno);
	return FILE_ERROR_FAILED;
	}
	}

	void File::DoInitialize(const FilePath& path, uint32_t flags) {
	DCHECK(!IsValid());

	int open_flags = 0;
	if (flags & FLAG_CREATE)
	open_flags = O_CREAT \| O_EXCL;

	if (flags & FLAG_CREATE_ALWAYS) {
	DCHECK(!open_flags);
	DCHECK(flags & FLAG_WRITE);
	open_flags = O_CREAT \| O_TRUNC;
	}

	if (!open_flags && !(flags & FLAG_OPEN)) {
	NOTREACHED();
	errno = EOPNOTSUPP;
	error_details_ = 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) {
	open_flags \|= O_RDONLY;
	} else {
	NOTREACHED();
	}

	int mode = S_IRUSR \| S_IWUSR;
	int descriptor = HANDLE_EINTR(open(path.value().c_str(), open_flags, mode));

	if (descriptor < 0) {
	error_details_ = File::GetLastFileError();
	return;
	}

	error_details_ = FILE_OK;
	file_.reset(descriptor);
	}

	bool File::Flush() {
	DCHECK(IsValid());

	#if defined(OS_LINUX)
	return !HANDLE_EINTR(fdatasync(file_.get()));
	#else
	return !HANDLE_EINTR(fsync(file_.get()));
	#endif
	}

	void File::SetPlatformFile(PlatformFile file) {
	DCHECK(!file_.is_valid());
	file_.reset(file);
	}

	// static
	File::Error File::GetLastFileError() {
	return base::File::OSErrorToFileError(errno);
	}

	} // namespace base