1 /*
2  * Copyright (C) 2018 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 "perfetto/ext/base/temp_file.h"
18 
19 #include "perfetto/base/build_config.h"
20 
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 
25 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
26 #include <Windows.h>
27 #include <direct.h>
28 #include <fileapi.h>
29 #include <io.h>
30 #else
31 #include <unistd.h>
32 #endif
33 
34 #include "perfetto/base/logging.h"
35 #include "perfetto/ext/base/file_utils.h"
36 #include "perfetto/ext/base/string_utils.h"
37 
38 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
39 namespace {
GetTempName()40 std::string GetTempName() {
41   char name[] = "perfetto-XXXXXX";
42   PERFETTO_CHECK(_mktemp_s(name, sizeof(name)) == 0);
43   return name;
44 }
45 }  // namespace
46 #endif
47 
48 namespace perfetto {
49 namespace base {
50 
GetSysTempDir()51 std::string GetSysTempDir() {
52   const char* tmpdir = nullptr;
53 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
54   if ((tmpdir = getenv("TMP")))
55     return tmpdir;
56   if ((tmpdir = getenv("TEMP")))
57     return tmpdir;
58   return "C:\\TEMP";
59 #else
60   if ((tmpdir = getenv("TMPDIR")))
61     return base::StripSuffix(tmpdir, "/");
62 #if PERFETTO_BUILDFLAG(PERFETTO_OS_ANDROID)
63   return "/data/local/tmp";
64 #else
65   return "/tmp";
66 #endif  // !OS_ANDROID
67 #endif  // !OS_WIN
68 }
69 
70 // static
Create()71 TempFile TempFile::Create() {
72   TempFile temp_file;
73 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
74   temp_file.path_ = GetSysTempDir() + "\\" + GetTempName();
75   // Several tests want to read-back the temp file while still open. On Windows,
76   // that requires FILE_SHARE_READ. FILE_SHARE_READ is NOT settable when using
77   // the POSIX-compat equivalent function _open(). Hence the CreateFileA +
78   // _open_osfhandle dance here.
79   HANDLE h =
80       ::CreateFileA(temp_file.path_.c_str(), GENERIC_READ | GENERIC_WRITE,
81                     FILE_SHARE_DELETE | FILE_SHARE_READ, nullptr, CREATE_ALWAYS,
82                     FILE_ATTRIBUTE_TEMPORARY, nullptr);
83   PERFETTO_CHECK(PlatformHandleChecker::IsValid(h));
84   // According to MSDN, when using _open_osfhandle the caller must not call
85   // CloseHandle(). Ownership is moved to the file descriptor, which then needs
86   // to be closed with just with _close().
87   temp_file.fd_.reset(_open_osfhandle(reinterpret_cast<intptr_t>(h), 0));
88 #else
89   temp_file.path_ = GetSysTempDir() + "/perfetto-XXXXXXXX";
90   temp_file.fd_.reset(mkstemp(&temp_file.path_[0]));
91 #endif
92   if (PERFETTO_UNLIKELY(!temp_file.fd_)) {
93     PERFETTO_FATAL("Could not create temp file %s", temp_file.path_.c_str());
94   }
95   return temp_file;
96 }
97 
98 // static
CreateUnlinked()99 TempFile TempFile::CreateUnlinked() {
100   TempFile temp_file = TempFile::Create();
101   temp_file.Unlink();
102   return temp_file;
103 }
104 
105 TempFile::TempFile() = default;
106 
~TempFile()107 TempFile::~TempFile() {
108   Unlink();
109 }
110 
ReleaseFD()111 ScopedFile TempFile::ReleaseFD() {
112   Unlink();
113   return std::move(fd_);
114 }
115 
Unlink()116 void TempFile::Unlink() {
117   if (path_.empty())
118     return;
119 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
120   // If the FD is still open DeleteFile will mark the file as pending deletion
121   // and delete it only when the process exists.
122   PERFETTO_CHECK(DeleteFileA(path_.c_str()));
123 #else
124   PERFETTO_CHECK(unlink(path_.c_str()) == 0);
125 #endif
126   path_.clear();
127 }
128 
129 TempFile::TempFile(TempFile&&) noexcept = default;
130 TempFile& TempFile::operator=(TempFile&&) = default;
131 
132 // static
Create()133 TempDir TempDir::Create() {
134   TempDir temp_dir;
135 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
136   temp_dir.path_ = GetSysTempDir() + "\\" + GetTempName();
137   PERFETTO_CHECK(_mkdir(temp_dir.path_.c_str()) == 0);
138 #else
139   temp_dir.path_ = GetSysTempDir() + "/perfetto-XXXXXXXX";
140   PERFETTO_CHECK(mkdtemp(&temp_dir.path_[0]));
141 #endif
142   return temp_dir;
143 }
144 
145 TempDir::TempDir() = default;
146 TempDir::TempDir(TempDir&&) noexcept = default;
147 TempDir& TempDir::operator=(TempDir&&) = default;
148 
~TempDir()149 TempDir::~TempDir() {
150   if (path_.empty())
151     return;  // For objects that get std::move()d.
152   PERFETTO_CHECK(Rmdir(path_));
153 }
154 
155 }  // namespace base
156 }  // namespace perfetto
157