ager@chromium.org | 9258b6b | 2008-09-11 09:11:10 +0000 | [diff] [blame] | 1 | // Copyright 2008 the V8 project authors. All rights reserved. |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | |
| 28 | #ifndef V8_SMART_POINTER_H_ |
| 29 | #define V8_SMART_POINTER_H_ |
| 30 | |
kasperl@chromium.org | 71affb5 | 2009-05-26 05:44:31 +0000 | [diff] [blame] | 31 | namespace v8 { |
| 32 | namespace internal { |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 33 | |
| 34 | |
kasperl@chromium.org | b912362 | 2008-09-17 14:05:56 +0000 | [diff] [blame] | 35 | // A 'scoped array pointer' that calls DeleteArray on its pointer when the |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 36 | // destructor is called. |
| 37 | template<typename T> |
| 38 | class SmartPointer { |
| 39 | public: |
kasperl@chromium.org | b912362 | 2008-09-17 14:05:56 +0000 | [diff] [blame] | 40 | |
| 41 | // Default constructor. Construct an empty scoped pointer. |
| 42 | inline SmartPointer() : p(NULL) {} |
| 43 | |
| 44 | |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 45 | // Construct a scoped pointer from a plain one. |
kasperl@chromium.org | b912362 | 2008-09-17 14:05:56 +0000 | [diff] [blame] | 46 | explicit inline SmartPointer(T* pointer) : p(pointer) {} |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 47 | |
| 48 | |
| 49 | // Copy constructor removes the pointer from the original to avoid double |
| 50 | // freeing. |
| 51 | inline SmartPointer(const SmartPointer<T>& rhs) : p(rhs.p) { |
| 52 | const_cast<SmartPointer<T>&>(rhs).p = NULL; |
| 53 | } |
| 54 | |
| 55 | |
kasperl@chromium.org | b912362 | 2008-09-17 14:05:56 +0000 | [diff] [blame] | 56 | // When the destructor of the scoped pointer is executed the plain pointer |
| 57 | // is deleted using DeleteArray. This implies that you must allocate with |
| 58 | // NewArray. |
| 59 | inline ~SmartPointer() { if (p) DeleteArray(p); } |
| 60 | |
| 61 | |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 62 | // You can get the underlying pointer out with the * operator. |
| 63 | inline T* operator*() { return p; } |
| 64 | |
| 65 | |
kasperl@chromium.org | b912362 | 2008-09-17 14:05:56 +0000 | [diff] [blame] | 66 | // You can use [n] to index as if it was a plain pointer |
| 67 | inline T& operator[](size_t i) { |
| 68 | return p[i]; |
| 69 | } |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 70 | |
| 71 | // We don't have implicit conversion to a T* since that hinders migration: |
| 72 | // You would not be able to change a method from returning a T* to |
| 73 | // returning an SmartPointer<T> and then get errors wherever it is used. |
| 74 | |
| 75 | |
| 76 | // If you want to take out the plain pointer and don't want it automatically |
| 77 | // deleted then call Detach(). Afterwards, the smart pointer is empty |
| 78 | // (NULL). |
| 79 | inline T* Detach() { |
| 80 | T* temp = p; |
| 81 | p = NULL; |
| 82 | return temp; |
| 83 | } |
| 84 | |
| 85 | |
| 86 | // Assignment requires an empty (NULL) SmartPointer as the receiver. Like |
| 87 | // the copy constructor it removes the pointer in the original to avoid |
| 88 | // double freeing. |
| 89 | inline SmartPointer& operator=(const SmartPointer<T>& rhs) { |
kasperl@chromium.org | 5a8ca6c | 2008-10-23 13:57:19 +0000 | [diff] [blame] | 90 | ASSERT(is_empty()); |
kasperl@chromium.org | b912362 | 2008-09-17 14:05:56 +0000 | [diff] [blame] | 91 | T* tmp = rhs.p; // swap to handle self-assignment |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 92 | const_cast<SmartPointer<T>&>(rhs).p = NULL; |
kasperl@chromium.org | b912362 | 2008-09-17 14:05:56 +0000 | [diff] [blame] | 93 | p = tmp; |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 94 | return *this; |
| 95 | } |
| 96 | |
| 97 | |
kasperl@chromium.org | 5a8ca6c | 2008-10-23 13:57:19 +0000 | [diff] [blame] | 98 | inline bool is_empty() { |
| 99 | return p == NULL; |
| 100 | } |
| 101 | |
| 102 | |
christian.plesner.hansen | 43d26ec | 2008-07-03 15:10:15 +0000 | [diff] [blame] | 103 | private: |
| 104 | T* p; |
| 105 | }; |
| 106 | |
| 107 | } } // namespace v8::internal |
| 108 | |
| 109 | #endif // V8_SMART_POINTER_H_ |