blob: 6e5e7a1582fbc8161494c85b0abe91f998a6cbb0 [file] [log] [blame]
/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "base/unix_file/fd_file.h"
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "base/logging.h"
namespace unix_file {
FdFile::FdFile() : guard_state_(GuardState::kClosed), fd_(-1), auto_close_(true) {
}
FdFile::FdFile(int fd, bool check_usage)
: guard_state_(check_usage ? GuardState::kBase : GuardState::kNoCheck),
fd_(fd), auto_close_(true) {
}
FdFile::FdFile(int fd, const std::string& path, bool check_usage)
: guard_state_(check_usage ? GuardState::kBase : GuardState::kNoCheck),
fd_(fd), file_path_(path), auto_close_(true) {
CHECK_NE(0U, path.size());
}
FdFile::~FdFile() {
if (kCheckSafeUsage && (guard_state_ < GuardState::kNoCheck)) {
if (guard_state_ < GuardState::kFlushed) {
LOG(::art::ERROR) << "File " << file_path_ << " wasn't explicitly flushed before destruction.";
}
if (guard_state_ < GuardState::kClosed) {
LOG(::art::ERROR) << "File " << file_path_ << " wasn't explicitly closed before destruction.";
}
CHECK_GE(guard_state_, GuardState::kClosed);
}
if (auto_close_ && fd_ != -1) {
if (Close() != 0) {
PLOG(::art::WARNING) << "Failed to close file " << file_path_;
}
}
}
void FdFile::moveTo(GuardState target, GuardState warn_threshold, const char* warning) {
if (kCheckSafeUsage) {
if (guard_state_ < GuardState::kNoCheck) {
if (warn_threshold < GuardState::kNoCheck && guard_state_ >= warn_threshold) {
LOG(::art::ERROR) << warning;
}
guard_state_ = target;
}
}
}
void FdFile::moveUp(GuardState target, const char* warning) {
if (kCheckSafeUsage) {
if (guard_state_ < GuardState::kNoCheck) {
if (guard_state_ < target) {
guard_state_ = target;
} else if (target < guard_state_) {
LOG(::art::ERROR) << warning;
}
}
}
}
void FdFile::DisableAutoClose() {
auto_close_ = false;
}
bool FdFile::Open(const std::string& path, int flags) {
return Open(path, flags, 0640);
}
bool FdFile::Open(const std::string& path, int flags, mode_t mode) {
CHECK_EQ(fd_, -1) << path;
fd_ = TEMP_FAILURE_RETRY(open(path.c_str(), flags, mode));
if (fd_ == -1) {
return false;
}
file_path_ = path;
static_assert(O_RDONLY == 0, "Readonly flag has unexpected value.");
if (kCheckSafeUsage && (flags & (O_RDWR | O_CREAT | O_WRONLY)) != 0) {
// Start in the base state (not flushed, not closed).
guard_state_ = GuardState::kBase;
} else {
// We are not concerned with read-only files. In that case, proper flushing and closing is
// not important.
guard_state_ = GuardState::kNoCheck;
}
return true;
}
int FdFile::Close() {
int result = TEMP_FAILURE_RETRY(close(fd_));
// Test here, so the file is closed and not leaked.
if (kCheckSafeUsage) {
CHECK_GE(guard_state_, GuardState::kFlushed) << "File " << file_path_
<< " has not been flushed before closing.";
moveUp(GuardState::kClosed, nullptr);
}
if (result == -1) {
return -errno;
} else {
fd_ = -1;
file_path_ = "";
return 0;
}
}
int FdFile::Flush() {
#ifdef __linux__
int rc = TEMP_FAILURE_RETRY(fdatasync(fd_));
#else
int rc = TEMP_FAILURE_RETRY(fsync(fd_));
#endif
moveUp(GuardState::kFlushed, "Flushing closed file.");
return (rc == -1) ? -errno : rc;
}
int64_t FdFile::Read(char* buf, int64_t byte_count, int64_t offset) const {
#ifdef __linux__
int rc = TEMP_FAILURE_RETRY(pread64(fd_, buf, byte_count, offset));
#else
int rc = TEMP_FAILURE_RETRY(pread(fd_, buf, byte_count, offset));
#endif
return (rc == -1) ? -errno : rc;
}
int FdFile::SetLength(int64_t new_length) {
#ifdef __linux__
int rc = TEMP_FAILURE_RETRY(ftruncate64(fd_, new_length));
#else
int rc = TEMP_FAILURE_RETRY(ftruncate(fd_, new_length));
#endif
moveTo(GuardState::kBase, GuardState::kClosed, "Truncating closed file.");
return (rc == -1) ? -errno : rc;
}
int64_t FdFile::GetLength() const {
struct stat s;
int rc = TEMP_FAILURE_RETRY(fstat(fd_, &s));
return (rc == -1) ? -errno : s.st_size;
}
int64_t FdFile::Write(const char* buf, int64_t byte_count, int64_t offset) {
#ifdef __linux__
int rc = TEMP_FAILURE_RETRY(pwrite64(fd_, buf, byte_count, offset));
#else
int rc = TEMP_FAILURE_RETRY(pwrite(fd_, buf, byte_count, offset));
#endif
moveTo(GuardState::kBase, GuardState::kClosed, "Writing into closed file.");
return (rc == -1) ? -errno : rc;
}
int FdFile::Fd() const {
return fd_;
}
bool FdFile::IsOpened() const {
return fd_ >= 0;
}
bool FdFile::ReadFully(void* buffer, size_t byte_count) {
char* ptr = static_cast<char*>(buffer);
while (byte_count > 0) {
ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd_, ptr, byte_count));
if (bytes_read <= 0) {
// 0: end of file
// -1: error
return false;
}
byte_count -= bytes_read; // Reduce the number of remaining bytes.
ptr += bytes_read; // Move the buffer forward.
}
return true;
}
bool FdFile::WriteFully(const void* buffer, size_t byte_count) {
const char* ptr = static_cast<const char*>(buffer);
moveTo(GuardState::kBase, GuardState::kClosed, "Writing into closed file.");
while (byte_count > 0) {
ssize_t bytes_written = TEMP_FAILURE_RETRY(write(fd_, ptr, byte_count));
if (bytes_written == -1) {
return false;
}
byte_count -= bytes_written; // Reduce the number of remaining bytes.
ptr += bytes_written; // Move the buffer forward.
}
return true;
}
void FdFile::Erase() {
TEMP_FAILURE_RETRY(SetLength(0));
TEMP_FAILURE_RETRY(Flush());
TEMP_FAILURE_RETRY(Close());
}
int FdFile::FlushCloseOrErase() {
int flush_result = TEMP_FAILURE_RETRY(Flush());
if (flush_result != 0) {
LOG(::art::ERROR) << "CloseOrErase failed while flushing a file.";
Erase();
return flush_result;
}
int close_result = TEMP_FAILURE_RETRY(Close());
if (close_result != 0) {
LOG(::art::ERROR) << "CloseOrErase failed while closing a file.";
Erase();
return close_result;
}
return 0;
}
int FdFile::FlushClose() {
int flush_result = TEMP_FAILURE_RETRY(Flush());
if (flush_result != 0) {
LOG(::art::ERROR) << "FlushClose failed while flushing a file.";
}
int close_result = TEMP_FAILURE_RETRY(Close());
if (close_result != 0) {
LOG(::art::ERROR) << "FlushClose failed while closing a file.";
}
return (flush_result != 0) ? flush_result : close_result;
}
} // namespace unix_file