1 /*
2  * Copyright (c) 2008-2015 Mozilla Foundation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20  * DEALINGS IN THE SOFTWARE.
21  */
22 
23 #ifndef jArray_h
24 #define jArray_h
25 
26 #include "mozilla/Attributes.h"
27 #include "mozilla/BinarySearch.h"
28 #include "nsDebug.h"
29 
30 template <class T, class L>
31 struct staticJArray {
32   const T* arr;
33   const L length;
34   operator T*() { return arr; }
35   T& operator[](L const index) {
36     MOZ_ASSERT(index >= 0, "Array access with negative index.");
37     MOZ_ASSERT(index < length, "Array index out of bounds.");
38     return ((T*)arr)[index];
39   }
binarySearchstaticJArray40   L binarySearch(T const elem) {
41     size_t idx;
42     bool found = mozilla::BinarySearch(arr, 0, length, elem, &idx);
43     return found ? idx : -1;
44   }
45 };
46 
47 template <class T, class L>
48 class autoJArray;
49 
50 template <class T, class L>
51 class jArray {
52   friend class autoJArray<T, L>;
53 
54  private:
55   T* arr;
56 
57  public:
58   L length;
newJArray(L const len)59   static jArray<T, L> newJArray(L const len) {
60     MOZ_ASSERT(len >= 0, "Negative length.");
61     jArray<T, L> newArray = {new T[size_t(len)], len};
62     return newArray;
63   }
newFallibleJArray(L const len)64   static jArray<T, L> newFallibleJArray(L const len) {
65     MOZ_ASSERT(len >= 0, "Negative length.");
66     T* a = new (mozilla::fallible) T[size_t(len)];
67     jArray<T, L> newArray = {a, a ? len : 0};
68     return newArray;
69   }
70   operator T*() { return arr; }
71   T& operator[](L const index) {
72     MOZ_ASSERT(index >= 0, "Array access with negative index.");
73     MOZ_ASSERT(index < length, "Array index out of bounds.");
74     return arr[index];
75   }
76   void operator=(staticJArray<T, L>& other) {
77     arr = (T*)other.arr;
78     length = other.length;
79   }
jArray(decltype (nullptr))80   MOZ_IMPLICIT jArray(decltype(nullptr)) : arr(nullptr), length(0) {}
jArray()81   jArray() : arr(nullptr), length(0) {}
82 
83  private:
jArray(T * aArr,L aLength)84   jArray(T* aArr, L aLength) : arr(aArr), length(aLength) {}
85 };
86 
87 template <class T, class L>
88 class autoJArray {
89  private:
90   T* arr;
91 
92  public:
93   L length;
autoJArray()94   autoJArray() : arr(0), length(0) {}
autoJArray(const jArray<T,L> & other)95   MOZ_IMPLICIT autoJArray(const jArray<T, L>& other)
96       : arr(other.arr), length(other.length) {}
~autoJArray()97   ~autoJArray() { delete[] arr; }
98   operator T*() { return arr; }
99   T& operator[](L const index) {
100     MOZ_ASSERT(index >= 0, "Array access with negative index.");
101     MOZ_ASSERT(index < length, "Array index out of bounds.");
102     return arr[index];
103   }
104   operator jArray<T, L>() {
105     // WARNING! This makes it possible to goof with buffer ownership!
106     // This is needed for the getStack and getListOfActiveFormattingElements
107     // methods to work sensibly.
108     jArray<T, L> newArray = {arr, length};
109     return newArray;
110   }
111   void operator=(const jArray<T, L>& other) {
112     delete[] arr;
113     arr = other.arr;
114     length = other.length;
115   }
decltype(nullptr)116   void operator=(decltype(nullptr)) {
117     // Make assigning null to an array in Java delete the buffer in C++
118     delete[] arr;
119     arr = nullptr;
120     length = 0;
121   }
122 };
123 
124 #endif  // jArray_h
125