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 <fcntl.h>
20 #include <sys/stat.h>
21 #include <sys/types.h>
22
23 #include <cstddef>
24 #include <memory>
25
26 #include <android-base/logging.h>
27
28 #include "unix_file/fd_file.h"
29
30 namespace art {
31
OpenFileForReading(const char * name)32 File* OS::OpenFileForReading(const char* name) {
33 return OpenFileWithFlags(name, O_RDONLY);
34 }
35
OpenFileReadWrite(const char * name)36 File* OS::OpenFileReadWrite(const char* name) {
37 return OpenFileWithFlags(name, O_RDWR);
38 }
39
CreateEmptyFile(const char * name,int extra_flags)40 static File* CreateEmptyFile(const char* name, int extra_flags) {
41 // In case the file exists, unlink it so we get a new file. This is necessary as the previous
42 // file may be in use and must not be changed.
43 unlink(name);
44
45 return OS::OpenFileWithFlags(name, O_CREAT | extra_flags);
46 }
47
CreateEmptyFile(const char * name)48 File* OS::CreateEmptyFile(const char* name) {
49 return art::CreateEmptyFile(name, O_RDWR | O_TRUNC);
50 }
51
CreateEmptyFileWriteOnly(const char * name)52 File* OS::CreateEmptyFileWriteOnly(const char* name) {
53 #ifdef _WIN32
54 int flags = O_WRONLY | O_TRUNC;
55 #else
56 int flags = O_WRONLY | O_TRUNC | O_NOFOLLOW | O_CLOEXEC;
57 #endif
58 return art::CreateEmptyFile(name, flags);
59 }
60
OpenFileWithFlags(const char * name,int flags,bool auto_flush)61 File* OS::OpenFileWithFlags(const char* name, int flags, bool auto_flush) {
62 CHECK(name != nullptr);
63 bool read_only = ((flags & O_ACCMODE) == O_RDONLY);
64 bool check_usage = !read_only && auto_flush;
65 std::unique_ptr<File> file(
66 new File(name, flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH, check_usage));
67 if (!file->IsOpened()) {
68 return nullptr;
69 }
70 return file.release();
71 }
72
FileExists(const char * name,bool check_file_type)73 bool OS::FileExists(const char* name, bool check_file_type) {
74 struct stat st;
75 if (stat(name, &st) == 0) {
76 if (check_file_type) {
77 return S_ISREG(st.st_mode); // TODO: Deal with symlinks?
78 } else {
79 return true;
80 }
81 } else {
82 return false;
83 }
84 }
85
DirectoryExists(const char * name)86 bool OS::DirectoryExists(const char* name) {
87 struct stat st;
88 if (stat(name, &st) == 0) {
89 return S_ISDIR(st.st_mode); // TODO: Deal with symlinks?
90 } else {
91 return false;
92 }
93 }
94
GetFileSizeBytes(const char * name)95 int64_t OS::GetFileSizeBytes(const char* name) {
96 struct stat st;
97 if (stat(name, &st) == 0) {
98 return st.st_size; // TODO: Deal with symlinks? According to the documentation,
99 // the st_size for a symlink is "the length of the pathname
100 // it contains, without a terminating null byte."
101 } else {
102 return -1;
103 }
104 }
105
106 } // namespace art
107