1 /*
2  * Copyright (C) 2016 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 #ifndef UTIL_H_
18 #define UTIL_H_
19 
20 #include <cstdlib>
21 #include <memory>
22 #include <sstream>
23 #include <vector>
24 
25 #include <android-base/macros.h>
26 #include <util/map_ptr.h>
27 
28 #include "androidfw/StringPiece.h"
29 
30 #ifdef __ANDROID__
31 #define ANDROID_LOG(x) LOG(x)
32 #else
33 #define ANDROID_LOG(x) std::stringstream()
34 #endif
35 
36 namespace android {
37 namespace util {
38 
39 /**
40  * Makes a std::unique_ptr<> with the template parameter inferred by the
41  * compiler.
42  * This will be present in C++14 and can be removed then.
43  */
44 template <typename T, class... Args>
make_unique(Args &&...args)45 std::unique_ptr<T> make_unique(Args&&... args) {
46   return std::unique_ptr<T>(new T{std::forward<Args>(args)...});
47 }
48 
49 // Based on std::unique_ptr, but uses free() to release malloc'ed memory
50 // without incurring the size increase of holding on to a custom deleter.
51 template <typename T>
52 class unique_cptr {
53  public:
54   using pointer = typename std::add_pointer<T>::type;
55 
unique_cptr()56   constexpr unique_cptr() : ptr_(nullptr) {}
unique_cptr(std::nullptr_t)57   constexpr explicit unique_cptr(std::nullptr_t) : ptr_(nullptr) {}
unique_cptr(pointer ptr)58   explicit unique_cptr(pointer ptr) : ptr_(ptr) {}
unique_cptr(unique_cptr && o)59   unique_cptr(unique_cptr&& o) noexcept : ptr_(o.ptr_) { o.ptr_ = nullptr; }
60 
~unique_cptr()61   ~unique_cptr() { std::free(reinterpret_cast<void*>(ptr_)); }
62 
63   inline unique_cptr& operator=(unique_cptr&& o) noexcept {
64     if (&o == this) {
65       return *this;
66     }
67 
68     std::free(reinterpret_cast<void*>(ptr_));
69     ptr_ = o.ptr_;
70     o.ptr_ = nullptr;
71     return *this;
72   }
73 
74   inline unique_cptr& operator=(std::nullptr_t) {
75     std::free(reinterpret_cast<void*>(ptr_));
76     ptr_ = nullptr;
77     return *this;
78   }
79 
release()80   pointer release() {
81     pointer result = ptr_;
82     ptr_ = nullptr;
83     return result;
84   }
85 
get()86   inline pointer get() const { return ptr_; }
87 
88   void reset(pointer ptr = pointer()) {
89     if (ptr == ptr_) {
90       return;
91     }
92 
93     pointer old_ptr = ptr_;
94     ptr_ = ptr;
95     std::free(reinterpret_cast<void*>(old_ptr));
96   }
97 
swap(unique_cptr & o)98   inline void swap(unique_cptr& o) { std::swap(ptr_, o.ptr_); }
99 
100   inline explicit operator bool() const { return ptr_ != nullptr; }
101 
102   inline typename std::add_lvalue_reference<T>::type operator*() const { return *ptr_; }
103 
104   inline pointer operator->() const { return ptr_; }
105 
106   inline bool operator==(const unique_cptr& o) const { return ptr_ == o.ptr_; }
107 
108   inline bool operator!=(const unique_cptr& o) const { return ptr_ != o.ptr_; }
109 
110   inline bool operator==(std::nullptr_t) const { return ptr_ == nullptr; }
111 
112   inline bool operator!=(std::nullptr_t) const { return ptr_ != nullptr; }
113 
114  private:
115   DISALLOW_COPY_AND_ASSIGN(unique_cptr);
116 
117   pointer ptr_;
118 };
119 
120 void ReadUtf16StringFromDevice(const uint16_t* src, size_t len, std::string* out);
121 
122 // Converts a UTF-8 string to a UTF-16 string.
123 std::u16string Utf8ToUtf16(const StringPiece& utf8);
124 
125 // Converts a UTF-16 string to a UTF-8 string.
126 std::string Utf16ToUtf8(const StringPiece16& utf16);
127 
128 std::vector<std::string> SplitAndLowercase(const android::StringPiece& str, char sep);
129 
130 template <typename T>
IsFourByteAligned(const incfs::map_ptr<T> & data)131 inline bool IsFourByteAligned(const incfs::map_ptr<T>& data) {
132   return ((size_t)data.unsafe_ptr() & 0x3U) == 0;
133 }
134 
IsFourByteAligned(const void * data)135 inline bool IsFourByteAligned(const void* data) {
136   return ((size_t)data & 0x3U) == 0;
137 }
138 
139 }  // namespace util
140 }  // namespace android
141 
142 #endif /* UTIL_H_ */
143