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/*
* Copyright (C) 2010 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 "os.h"
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <cstddef>
#include <memory>
#include <android-base/logging.h>
#include "unix_file/fd_file.h"
namespace art {
File* OS::OpenFileForReading(const char* name) {
return OpenFileWithFlags(name, O_RDONLY);
}
File* OS::OpenFileReadWrite(const char* name) {
return OpenFileWithFlags(name, O_RDWR);
}
static File* CreateEmptyFile(const char* name, int extra_flags) {
// In case the file exists, unlink it so we get a new file. This is necessary as the previous
// file may be in use and must not be changed.
unlink(name);
return OS::OpenFileWithFlags(name, O_CREAT | extra_flags);
}
File* OS::CreateEmptyFile(const char* name) {
return art::CreateEmptyFile(name, O_RDWR | O_TRUNC);
}
File* OS::CreateEmptyFileWriteOnly(const char* name) {
#ifdef _WIN32
int flags = O_WRONLY | O_TRUNC;
#else
int flags = O_WRONLY | O_TRUNC | O_NOFOLLOW | O_CLOEXEC;
#endif
return art::CreateEmptyFile(name, flags);
}
File* OS::OpenFileWithFlags(const char* name, int flags, bool auto_flush) {
CHECK(name != nullptr);
bool read_only = ((flags & O_ACCMODE) == O_RDONLY);
bool check_usage = !read_only && auto_flush;
std::unique_ptr<File> file(
new File(name, flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH, check_usage));
if (!file->IsOpened()) {
return nullptr;
}
return file.release();
}
bool OS::FileExists(const char* name, bool check_file_type) {
struct stat st;
if (stat(name, &st) == 0) {
if (check_file_type) {
return S_ISREG(st.st_mode); // TODO: Deal with symlinks?
} else {
return true;
}
} else {
return false;
}
}
bool OS::DirectoryExists(const char* name) {
struct stat st;
if (stat(name, &st) == 0) {
return S_ISDIR(st.st_mode); // TODO: Deal with symlinks?
} else {
return false;
}
}
int64_t OS::GetFileSizeBytes(const char* name) {
struct stat st;
if (stat(name, &st) == 0) {
return st.st_size; // TODO: Deal with symlinks? According to the documentation,
// the st_size for a symlink is "the length of the pathname
// it contains, without a terminating null byte."
} else {
return -1;
}
}
} // namespace art
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