1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "os.h"
18
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <fcntl.h>
22 #include <cstddef>
23 #include <memory>
24
25 #include "base/logging.h"
26 #include "base/unix_file/fd_file.h"
27
28 namespace art {
29
OpenFileForReading(const char * name)30 File* OS::OpenFileForReading(const char* name) {
31 return OpenFileWithFlags(name, O_RDONLY);
32 }
33
OpenFileReadWrite(const char * name)34 File* OS::OpenFileReadWrite(const char* name) {
35 return OpenFileWithFlags(name, O_RDWR);
36 }
37
CreateEmptyFile(const char * name,int extra_flags)38 static File* CreateEmptyFile(const char* name, int extra_flags) {
39 // In case the file exists, unlink it so we get a new file. This is necessary as the previous
40 // file may be in use and must not be changed.
41 unlink(name);
42
43 return OS::OpenFileWithFlags(name, O_CREAT | extra_flags);
44 }
45
CreateEmptyFile(const char * name)46 File* OS::CreateEmptyFile(const char* name) {
47 return art::CreateEmptyFile(name, O_RDWR | O_TRUNC);
48 }
49
CreateEmptyFileWriteOnly(const char * name)50 File* OS::CreateEmptyFileWriteOnly(const char* name) {
51 return art::CreateEmptyFile(name, O_WRONLY | O_TRUNC | O_NOFOLLOW | O_CLOEXEC);
52 }
53
OpenFileWithFlags(const char * name,int flags,bool auto_flush)54 File* OS::OpenFileWithFlags(const char* name, int flags, bool auto_flush) {
55 CHECK(name != nullptr);
56 bool read_only = ((flags & O_ACCMODE) == O_RDONLY);
57 bool check_usage = !read_only && auto_flush;
58 std::unique_ptr<File> file(new File(name, flags, 0666, check_usage));
59 if (!file->IsOpened()) {
60 return nullptr;
61 }
62 return file.release();
63 }
64
FileExists(const char * name)65 bool OS::FileExists(const char* name) {
66 struct stat st;
67 if (stat(name, &st) == 0) {
68 return S_ISREG(st.st_mode); // TODO: Deal with symlinks?
69 } else {
70 return false;
71 }
72 }
73
DirectoryExists(const char * name)74 bool OS::DirectoryExists(const char* name) {
75 struct stat st;
76 if (stat(name, &st) == 0) {
77 return S_ISDIR(st.st_mode); // TODO: Deal with symlinks?
78 } else {
79 return false;
80 }
81 }
82
83 } // namespace art
84